Rrp1b, a New Candidate Susceptibility Gene for Breast Cancer Progression and Metastasis

PubMed Central

Crawford, Nigel P. S; Qian, Xiaolan; Ziogas, Argyrios; Papageorge, Alex G; Boersma, Brenda J; Walker, Renard C; Lukes, Luanne; Rowe, William L; Zhang, Jinghui; Ambs, Stefan; Lowy, Douglas R; Anton-Culver, Hoda; Hunter, Kent W

2007-01-01

A novel candidate metastasis modifier, ribosomal RNA processing 1 homolog B (Rrp1b), was identified through two independent approaches. First, yeast two-hybrid, immunoprecipitation, and functional assays demonstrated a physical and functional interaction between Rrp1b and the previous identified metastasis modifier Sipa1. In parallel, using mouse and human metastasis gene expression data it was observed that extracellular matrix (ECM) genes are common components of metastasis predictive signatures, suggesting that ECM genes are either important markers or causal factors in metastasis. To investigate the relationship between ECM genes and poor prognosis in breast cancer, expression quantitative trait locus analysis of polyoma middle-T transgene-induced mammary tumor was performed. ECM gene expression was found to be consistently associated with Rrp1b expression. In vitro expression of Rrp1b significantly altered ECM gene expression, tumor growth, and dissemination in metastasis assays. Furthermore, a gene signature induced by ectopic expression of Rrp1b in tumor cells predicted survival in a human breast cancer gene expression dataset. Finally, constitutional polymorphism within RRP1B was found to be significantly associated with tumor progression in two independent breast cancer cohorts. These data suggest that RRP1B may be a novel susceptibility gene for breast cancer progression and metastasis. PMID:18081427

Evaluation of Allelic Expression of Imprinted Genes in Adult Human Blood

PubMed Central

Frost, Jennifer M.; Monk, Dave; Stojilkovic-Mikic, Taita; Woodfine, Kathryn; Chitty, Lyn S.; Murrell, Adele; Stanier, Philip; Moore, Gudrun E.

2010-01-01

Background Imprinted genes are expressed from only one allele in a parent-of-origin dependent manner. Loss of imprinted (LOI) expression can result in a variety of human disorders and is frequently reported in cancer. Biallelic expression of imprinted genes in adult blood has been suggested as a useful biomarker and is currently being investigated in colorectal cancer. In general, the expression profiles of imprinted genes are well characterised during human and mouse fetal development, but not in human adults. Methodology/Principal Findings We investigated quantitative expression of 36 imprinted genes in adult human peripheral blood leukocytes obtained from healthy individuals. Allelic expression was also investigated in B and T lymphocytes and myeloid cells. We found that 21 genes were essentially undetectable in adult blood. Only six genes were demonstrably monoallelic, and most importantly, we found that nine genes were either biallelic or showed variable expression in different individuals. Separated leukocyte populations showed the same expression patterns as whole blood. Differential methylation at each of the imprinting control loci analysed was maintained, including regions that contained biallelically expressed genes. This suggests in some cases methylation has become uncoupled from its role in regulating gene expression. Conclusions/Significance We conclude that only a limited set of imprinted genes, including IGF2 and SNRPN, may be useful for LOI cancer biomarker studies. In addition, blood is not a good tissue to use for the discovery of new imprinted genes. Finally, lymphocyte DNA methylation status in the adult may not always be a reliable indicator of monoallelic gene expression. PMID:21042416

Gene expression profiling data of Schizosaccharomyces pombe under nitrosative stress using differential display.

PubMed

Biswas, Pranjal; Majumdar, Uddalak; Ghosh, Sanjay

2016-03-01

Excess production of nitric oxide (NO) and reactive nitrogen intermediates (RNIs) causes nitrosative stress on cells. Schizosaccharomyces pombe was used as a model to study nitrosative stress response. In the present data article, we have used differential display to identify the differentially expressed genes in the fission yeast under nitrosative stress conditions. We have used pure NO donor compound detaNONOate at final concentrations of 0.1 mM and 1 mM to treat the cells for 15 min alongside control before studying their gene expression profiles. At both the treated conditions, we identified genes which were commonly repressed while several genes were induced upon both 0.1 mM and 1 mM treatments. The differentially expressed genes were further analyzed in DAVID and categorized into several different pathways.

Alterations in Bronchial Airway miRNA Expression for Lung Cancer Detection.

PubMed

Pavel, Ana B; Campbell, Joshua D; Liu, Gang; Elashoff, David; Dubinett, Steven; Smith, Kate; Whitney, Duncan; Lenburg, Marc E; Spira, Avrum

2017-11-01

We have previously shown that gene expression alterations in normal-appearing bronchial epithelial cells can serve as a lung cancer detection biomarker in smokers. Given that miRNAs regulate airway gene expression responses to smoking, we evaluated whether miRNA expression is also altered in the bronchial epithelium of smokers with lung cancer. Using epithelial brushings from the mainstem bronchus of patients undergoing bronchoscopy for suspected lung cancer (as part of the AEGIS-1/2 clinical trials), we profiled miRNA expression via small-RNA sequencing from 347 current and former smokers for which gene expression data were also available. Patients were followed for one year postbronchoscopy until a final diagnosis of lung cancer ( n = 194) or benign disease ( n = 153) was made. Following removal of 6 low-quality samples, we used 138 patients (AEGIS-1) as a discovery set to identify four miRNAs (miR-146a-5p, miR-324-5p, miR-223-3p, and miR-223-5p) that were downregulated in the bronchial airway of lung cancer patients (ANOVA P < 0.002, FDR < 0.2). The expression of these miRNAs is significantly more negatively correlated with the expression of their mRNA targets than with the expression of other nontarget genes (K-S P < 0.05). Furthermore, these mRNA targets are enriched among genes whose expression is elevated in cancer patients (GSEA FDR < 0.001). Finally, we found that the addition of miR-146a-5p to an existing mRNA biomarker for lung cancer significantly improves its performance (AUC) in the 203 samples (AEGIS-1/2) serving an independent test set (DeLong P < 0.05). Our findings suggest that there are miRNAs whose expression is altered in the cytologically normal bronchial epithelium of smokers with lung cancer, and that they may regulate cancer-associated gene expression differences. Cancer Prev Res; 10(11); 651-9. ©2017 AACR . ©2017 American Association for Cancer Research.

Identification of Homeotic Target Genes in Drosophila Melanogaster Including Nervy, a Proto-Oncogene Homologue

PubMed Central

Feinstein, P. G.; Kornfeld, K.; Hogness, D. S.; Mann, R. S.

1995-01-01

In Drosophila, the specific morphological characteristics of each segment are determined by the homeotic genes that regulate the expression of downstream target genes. We used a subtractive hybridization procedure to isolate activated target genes of the homeotic gene Ultrabithorax (Ubx). In addition, we constructed a set of mutant genotypes that measures the regulatory contribution of individual homeotic genes to a complex target gene expression pattern. Using these mutants, we demonstrate that homeotic genes can regulate target gene expression at the start of gastrulation, suggesting a previously unknown role for the homeotic genes at this early stage. We also show that, in abdominal segments, the levels of expression for two target genes increase in response to high levels of Ubx, demonstrating that the normal down-regulation of Ubx in these segments is functional. Finally, the DNA sequence of cDNAs for one of these genes predicts a protein that is similar to a human proto-oncogene involved in acute myeloid leukemias. These results illustrate potentially general rules about the homeotic control of target gene expression and suggest that subtractive hybridization can be used to isolate interesting homeotic target genes. PMID:7498738

Expression of Fushi tarazu factor 1 homolog and Pit-1 genes in the pituitaries of pre-spawning chum and sockeye salmon.

PubMed

Higa, M; Ando, H; Urano, A

2001-06-01

Fushi tarazu factor-1 (FTZ-F1) and Pit-1 are major pituitary transcription factors, controlling expression of genes coding for gonadotropin (GTH) subunits and growth hormone/prolactin/somatolactin family hormone, respectively. As a first step to investigate physiological factors regulating gene expression of these transcription factors, we determined their mRNA levels in the pituitaries of chum salmon (Oncorhynchus keta) at different stages of sexual maturation. FTZ-F1 gene expression was increased in males at the stage before spermiation, where the levels of GTH alpha and IIbeta subunit mRNAs were elevated. Pit-1 mRNA showed maximum levels at the final stage of sexual maturation in both sexes, when expression of somatolactin gene peaked. To clarify whether gonadotropin-releasing hormone (GnRH) is involved in these increases in FTZ-F1 and Pit-1 gene expression, we examined effects of GnRH analog (GnRHa) administration on their gene expression in maturing sockeye salmon (Oncorhynchus nerka). GnRHa stimulated Pit-1 gene expression in females only, but failed to stimulate FTZ-F1 gene expression in both sexes. The up-regulated expression of FTZ-F1 and Pit-1 genes at the pre-spawning stages suggest that the two transcription factors have roles in sexual maturation of salmonids. Physiological factors regulating gene expression of FTZ-F1 and Pit-1 are discussed in this review.

Dynamics of the yeast transcriptome during wine fermentation reveals a novel fermentation stress response

PubMed Central

Marks, Virginia D.; Ho Sui, Shannan J.; Erasmus, Daniel; van der Merwe, George K.; Brumm, Jochen; Wasserman, Wyeth W.; Bryan, Jennifer; van Vuuren, Hennie J. J.

2016-01-01

In this study, genome-wide expression analyses were used to study the response of Saccharomyces cerevisiae to stress throughout a 15-day wine fermentation. Forty per cent of the yeast genome significantly changed expression levels to mediate long-term adaptation to fermenting grape must. Among the genes that changed expression levels, a group of 223 genes was identified, which was designated as fermentation stress response (FSR) genes that were dramatically induced at various points during fermentation. FSR genes sustain high levels of induction up to the final time point and exhibited changes in expression levels ranging from four- to 80-fold. The FSR is novel; 62% of the genes involved have not been implicated in global stress responses and 28% of the FSR genes have no functional annotation. Genes involved in respiratory metabolism and gluconeogenesis were expressed during fermentation despite the presence of high concentrations of glucose. Ethanol, rather than nutrient depletion, seems to be responsible for entry of yeast cells into the stationary phase. PMID:18215224

Targeting pancreatic expressed PAX genes for the treatment of diabetes mellitus and pancreatic neuroendocrine tumors.

PubMed

Martin-Montalvo, Alejandro; Lorenzo, Petra I; López-Noriega, Livia; Gauthier, Benoit R

2017-01-01

Four members of the PAX family, PAX2, PAX4, PAX6 and PAX8 are known to be expressed in the pancreas. Accumulated evidences indicate that several pancreatic expressed PAX genes play a significant role in pancreatic development/functionality and alterations in these genes are involved in the pathogenesis of pancreatic diseases. Areas covered: In this review, we summarize the ongoing research related to pancreatic PAX genes in diabetes mellitus and pancreatic neuroendocrine tumors. We dissect the current knowledge at different levels; from mechanistic studies in cell lines performed to understand the molecular processes controlled by pancreatic PAX genes, to in vivo studies using rodent models that over-express or lack specific PAX genes. Finally, we describe human studies associating variants on pancreatic-expressed PAX genes with pancreatic diseases. Expert opinion: Based on the current literature, we propose that future interventions to treat pancreatic neuroendocrine tumors and diabetes mellitus could be developed via the modulation of PAX4 and/or PAX6 regulated pathways.

From Saccharomyces cerevisiae to human: The important gene co-expression modules.

PubMed

Liu, Wei; Li, Li; Ye, Hua; Chen, Haiwei; Shen, Weibiao; Zhong, Yuexian; Tian, Tian; He, Huaqin

2017-08-01

Network-based systems biology has become an important method for analyzing high-throughput gene expression data and gene function mining. Yeast has long been a popular model organism for biomedical research. In the current study, a weighted gene co-expression network analysis algorithm was applied to construct a gene co-expression network in Saccharomyces cerevisiae . Seventeen stable gene co-expression modules were detected from 2,814 S. cerevisiae microarray data. Further characterization of these modules with the Database for Annotation, Visualization and Integrated Discovery tool indicated that these modules were associated with certain biological processes, such as heat response, cell cycle, translational regulation, mitochondrion oxidative phosphorylation, amino acid metabolism and autophagy. Hub genes were also screened by intra-modular connectivity. Finally, the module conservation was evaluated in a human disease microarray dataset. Functional modules were identified in budding yeast, some of which are associated with patient survival. The current study provided a paradigm for single cell microorganisms and potentially other organisms.

Transgenic over-expression of YY1 induces pathologic cardiac hypertrophy in a sex-specific manner

PubMed Central

Stauffer, Brian L.; Dockstader, Karen; Russell, Gloria; Hijmans, Jamie; Walker, Lisa; Cecil, Mackenzie; Demos-Davies, Kimberly; Medway, Allen; McKinsey, Timothy A.; Sucharov, Carmen C.

2015-01-01

YY1 can activate or repress transcription of various genes. In cardiac myocytes in culture YY1 has been shown to regulate expression of several genes involved in myocyte pathology. YY1 can also acutely protect the heart against detrimental changes in gene expression. In this study we show that cardiac over-expression of YY1 induces pathologic cardiac hypertrophy in male mice, measured by changes in gene expression and lower ejection fraction/fractional shortening. In contrast, female animals are protected against pathologic gene expression changes and cardiac dysfunction. Furthermore, we show that YY1 regulates, in a sex-specific manner, the expression of mammalian enable (Mena), a factor that regulates cytoskeletal actin dynamics and whose expression is increased in several models of cardiac pathology, and that Mena expression in humans with heart failure is sex-dependent. Finally, we show that sex differences in YY1 expression are also observed in human heart failure. In summary, this is the first work to show that YY1 has a sex-specific effect in the regulation of cardiac pathology. PMID:25935483

Differential gene expression analysis in glioblastoma cells and normal human brain cells based on GEO database.

PubMed

Wang, Anping; Zhang, Guibin

2017-11-01

The differentially expressed genes between glioblastoma (GBM) cells and normal human brain cells were investigated to performed pathway analysis and protein interaction network analysis for the differentially expressed genes. GSE12657 and GSE42656 gene chips, which contain gene expression profile of GBM were obtained from Gene Expression Omniub (GEO) database of National Center for Biotechnology Information (NCBI). The 'limma' data packet in 'R' software was used to analyze the differentially expressed genes in the two gene chips, and gene integration was performed using 'RobustRankAggreg' package. Finally, pheatmap software was used for heatmap analysis and Cytoscape, DAVID, STRING and KOBAS were used for protein-protein interaction, Gene Ontology (GO) and KEGG analyses. As results: i) 702 differentially expressed genes were identified in GSE12657, among those genes, 548 were significantly upregulated and 154 were significantly downregulated (p<0.01, fold-change >1), and 1,854 differentially expressed genes were identified in GSE42656, among the genes, 1,068 were significantly upregulated and 786 were significantly downregulated (p<0.01, fold-change >1). A total of 167 differentially expressed genes including 100 upregulated genes and 67 downregulated genes were identified after gene integration, and the genes showed significantly different expression levels in GBM compared with normal human brain cells (p<0.05). ii) Interactions between the protein products of 101 differentially expressed genes were identified using STRING and expression network was established. A key gene, called CALM3, was identified by Cytoscape software. iii) GO enrichment analysis showed that differentially expressed genes were mainly enriched in 'neurotransmitter:sodium symporter activity' and 'neurotransmitter transporter activity', which can affect the activity of neurotransmitter transportation. KEGG pathway analysis showed that the differentially expressed genes were mainly enriched in 'protein processing in endoplasmic reticulum', which can affect protein processing in endoplasmic reticulum. The results showed that: i) 167 differentially expressed genes were identified from two gene chips after integration; and ii) protein interaction network was established, and GO and KEGG pathway analyses were successfully performed to identify and annotate the key gene, which provide new insights for the studies on GBN at gene level.

Genome-wide profiling identifies a subset of methamphetamine (METH)-induced genes associated with METH-induced increased H4K5Ac binding in the rat striatum

PubMed Central

2013-01-01

Background METH is an illicit drug of abuse that influences gene expression in the rat striatum. Histone modifications regulate gene transcription. Methods We therefore used microarray analysis and genome-scale approaches to examine potential relationships between the effects of METH on gene expression and on DNA binding of histone H4 acetylated at lysine 4 (H4K5Ac) in the rat dorsal striatum of METH-naïve and METH-pretreated rats. Results Acute and chronic METH administration caused differential changes in striatal gene expression. METH also increased H4K5Ac binding around the transcriptional start sites (TSSs) of genes in the rat striatum. In order to relate gene expression to histone acetylation, we binned genes of similar expression into groups of 100 genes and proceeded to relate gene expression to H4K5Ac binding. We found a positive correlation between gene expression and H4K5Ac binding in the striatum of control rats. Similar correlations were observed in METH-treated rats. Genes that showed acute METH-induced increased expression in saline-pretreated rats also showed METH-induced increased H4K5Ac binding. The acute METH injection caused similar increases in H4K5Ac binding in METH-pretreated rats, without affecting gene expression to the same degree. Finally, genes that showed METH-induced decreased expression exhibited either decreases or no changes in H4K5Ac binding. Conclusion Acute METH injections caused increased gene expression of genes that showed increased H4K5Ac binding near their transcription start sites. PMID:23937714

Genome-wide profiling identifies a subset of methamphetamine (METH)-induced genes associated with METH-induced increased H4K5Ac binding in the rat striatum.

PubMed

Cadet, Jean Lud; Jayanthi, Subramaniam; McCoy, Michael T; Ladenheim, Bruce; Saint-Preux, Fabienne; Lehrmann, Elin; De, Supriyo; Becker, Kevin G; Brannock, Christie

2013-08-12

METH is an illicit drug of abuse that influences gene expression in the rat striatum. Histone modifications regulate gene transcription. We therefore used microarray analysis and genome-scale approaches to examine potential relationships between the effects of METH on gene expression and on DNA binding of histone H4 acetylated at lysine 4 (H4K5Ac) in the rat dorsal striatum of METH-naïve and METH-pretreated rats. Acute and chronic METH administration caused differential changes in striatal gene expression. METH also increased H4K5Ac binding around the transcriptional start sites (TSSs) of genes in the rat striatum. In order to relate gene expression to histone acetylation, we binned genes of similar expression into groups of 100 genes and proceeded to relate gene expression to H4K5Ac binding. We found a positive correlation between gene expression and H4K5Ac binding in the striatum of control rats. Similar correlations were observed in METH-treated rats. Genes that showed acute METH-induced increased expression in saline-pretreated rats also showed METH-induced increased H4K5Ac binding. The acute METH injection caused similar increases in H4K5Ac binding in METH-pretreated rats, without affecting gene expression to the same degree. Finally, genes that showed METH-induced decreased expression exhibited either decreases or no changes in H4K5Ac binding. Acute METH injections caused increased gene expression of genes that showed increased H4K5Ac binding near their transcription start sites.

Growth Factor Receptor-Directed Therapy in Human Breast Cancer

DTIC Science & Technology

1997-12-01

related more to acquired rather than to intrinsic drug resistance. 3) To define the role of HER-2 and heregulin gene expression in antiestrogen... treatment strategies in affected patients. 3) Role of HER-2 and heregulin gene expression in antiestrogen resistance. The hypothesis that heregulins may be a...native amplification/overexpression of the HER-2/neu gene and sion. Finally, to avoid the possibility that any observed are shown as positive controls

tortuga refines Notch pathway gene expression in the zebrafish presomitic mesoderm at the post-transcriptional level.

PubMed

Dill, Kariena K; Amacher, Sharon L

2005-11-15

We have identified the zebrafish tortuga (tor) gene by an ENU-induced mutation that disrupts the presomitic mesoderm (PSM) expression of Notch pathway genes. In tor mutants, Notch pathway gene expression persists in regions of the PSM where expression is normally off in wild type embryos. The expression of hairy/Enhancer of split-related 1 (her1) is affected first, followed by the delta genes deltaC and deltaD, and finally, by another hairy/Enhancer of split-related gene, her7. In situ hybridization with intron-specific probes for her1 and deltaC indicates that transcriptional bursts of expression are normal in tor mutants, suggesting that tor normally functions to refine her1 and deltaC message levels downstream of transcription. Despite the striking defects in Notch pathway gene expression, somite boundaries form normally in tor mutant embryos, although somitic mesoderm defects are apparent later, when cells mature to form muscle fibers. Thus, while the function of Notch pathway genes is required for proper somite formation, the tor mutant phenotype suggests that precise oscillations of Notch pathway transcripts are not essential for establishing segmental pattern in the presomitic mesoderm.

Identification and expression analyses of two genes encoding putative low-affinity nitrate transporters from Nicotiana plumbaginifolia.

PubMed

Fraisier, V; Dorbe, M F; Daniel-Vedele, F

2001-01-01

Higher plants have both high- and low-affinity nitrate uptake systems (HATS and LATS respectively). Here we report the isolation and characterization of two genes, NpNRT1.1 and NpNRT1.2, from Nicotiana plumbaginifolia whose structural features suggest that they both belong to the NRT1 gene family, which is involved in the LATS. Amino acid sequence alignment showed that the N. plumbaginifolia proteins have greater similarity to their corresponding tomato homologues than to each other. Genomic Southern blot analysis indicates that there are probably more than two members of this family in N. plumbaginifolia. Northern blot analysis shows that NpNRT1.2 expression is restricted strictly to roots, whereas NpNRT1.1, in addition to roots, is expressed at a basal level in all other plant organs. Likewise, differential expression in response to external treatments with various N sources was observed for these two genes: NpNRT1.1 can be considered as a constitutively expressed gene whereas NpNRT1.2 expression is dependent strictly on high nitrate concentrations. Finally, over-expression of a gene involved in the HATS does not lead to any modification of LATS gene expression.

An analysis of gene expression in PTSD implicates genes involved in the glucocorticoid receptor pathway and neural responses to stress

PubMed Central

Logue, Mark W.; Smith, Alicia K.; Baldwin, Clinton; Wolf, Erika J.; Guffanti, Guia; Ratanatharathorn, Andrew; Stone, Annjanette; Schichman, Steven A.; Humphries, Donald; Binder, Elisabeth B.; Arloth, Janine; Menke, Andreas; Uddin, Monica; Wildman, Derek; Galea, Sandro; Aiello, Allison E.; Koenen, Karestan C.; Miller, Mark W.

2015-01-01

We examined the association between posttraumatic stress disorder (PTSD) and gene expression using whole blood samples from a cohort of trauma-exposed white non-Hispanic male veterans (115 cases and 28 controls). 10,264 probes of genes and gene transcripts were analyzed. We found 41 that were differentially expressed in PTSD cases versus controls (multiple-testing corrected p<0.05). The most significant was DSCAM, a neurological gene expressed widely in the developing brain and in the amygdala and hippocampus of the adult brain. We then examined the 41 differentially expressed genes in a meta-analysis using two replication cohorts and found significant associations with PTSD for 7 of the 41 (p<0.05), one of which (ATP6AP1L) survived multiple-testing correction. There was also broad evidence of overlap across the discovery and replication samples for the entire set of genes implicated in the discovery data based on the direction of effect and an enrichment of p<0.05 significant probes beyond what would be expected under the null. Finally, we found that the set of differentially expressed genes from the discovery sample was enriched for genes responsive to glucocorticoid signaling with most showing reduced expression in PTSD cases compared to controls. PMID:25867994

Design of retrovirus vectors for transfer and expression of the human. beta. -globin gene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, A.D.; Bender, M.A.; Harris, E.A.S.

1988-11-01

Regulated expression of the human ..beta..-globin gene has been demonstrated in cultured murine erythroleukemia cells and in mice after retrovirus-mediated gene transfer. However, the low titer of recombinant viruses described to date results in relatively inefficient gene transfer, which limits their usefulness for animal studies and for potential gene therapy in humans for diseases involving defective ..beta..-globin genes. The authors found regions that interfered with virus production within intron 2 of the ..beta..-globin gene and on both sides of the gene. The flanking regions could be removed, but intron 2 was required for ..beta..-globin expression. Inclusion of ..beta..-globin introns necessitatesmore » an antisense orientation of the gene within the retrovirus vector. However, they found no effect of the antisense ..beta..-globin transcription on virus production. A region downstream of the ..beta..-globin gene that stimulates expression of the gene in transgenic mice was included in the viruses without detrimental effects on virus titer. Virus titers of over 10/sup 6/ CFU/ml were obtained with the final vector design, which retained the ability to direct regulated expression of human ..beta..-globin in murine erythroleukemia cells. The vector also allowed transfer and expression of the human ..beta..-globin gene in hematopoietic cells (CFU-S cells) in mice.« less

An RNA-Seq based gene expression atlas of the common bean.

PubMed

O'Rourke, Jamie A; Iniguez, Luis P; Fu, Fengli; Bucciarelli, Bruna; Miller, Susan S; Jackson, Scott A; McClean, Philip E; Li, Jun; Dai, Xinbin; Zhao, Patrick X; Hernandez, Georgina; Vance, Carroll P

2014-10-06

Common bean (Phaseolus vulgaris) is grown throughout the world and comprises roughly 50% of the grain legumes consumed worldwide. Despite this, genetic resources for common beans have been lacking. Next generation sequencing, has facilitated our investigation of the gene expression profiles associated with biologically important traits in common bean. An increased understanding of gene expression in common bean will improve our understanding of gene expression patterns in other legume species. Combining recently developed genomic resources for Phaseolus vulgaris, including predicted gene calls, with RNA-Seq technology, we measured the gene expression patterns from 24 samples collected from seven tissues at developmentally important stages and from three nitrogen treatments. Gene expression patterns throughout the plant were analyzed to better understand changes due to nodulation, seed development, and nitrogen utilization. We have identified 11,010 genes differentially expressed with a fold change ≥ 2 and a P-value < 0.05 between different tissues at the same time point, 15,752 genes differentially expressed within a tissue due to changes in development, and 2,315 genes expressed only in a single tissue. These analyses identified 2,970 genes with expression patterns that appear to be directly dependent on the source of available nitrogen. Finally, we have assembled this data in a publicly available database, The Phaseolus vulgaris Gene Expression Atlas (Pv GEA), http://plantgrn.noble.org/PvGEA/ . Using the website, researchers can query gene expression profiles of their gene of interest, search for genes expressed in different tissues, or download the dataset in a tabular form. These data provide the basis for a gene expression atlas, which will facilitate functional genomic studies in common bean. Analysis of this dataset has identified genes important in regulating seed composition and has increased our understanding of nodulation and impact of the nitrogen source on assimilation and distribution throughout the plant.

Bayesian approach to transforming public gene expression repositories into disease diagnosis databases.

PubMed

Huang, Haiyan; Liu, Chun-Chi; Zhou, Xianghong Jasmine

2010-04-13

The rapid accumulation of gene expression data has offered unprecedented opportunities to study human diseases. The National Center for Biotechnology Information Gene Expression Omnibus is currently the largest database that systematically documents the genome-wide molecular basis of diseases. However, thus far, this resource has been far from fully utilized. This paper describes the first study to transform public gene expression repositories into an automated disease diagnosis database. Particularly, we have developed a systematic framework, including a two-stage Bayesian learning approach, to achieve the diagnosis of one or multiple diseases for a query expression profile along a hierarchical disease taxonomy. Our approach, including standardizing cross-platform gene expression data and heterogeneous disease annotations, allows analyzing both sources of information in a unified probabilistic system. A high level of overall diagnostic accuracy was shown by cross validation. It was also demonstrated that the power of our method can increase significantly with the continued growth of public gene expression repositories. Finally, we showed how our disease diagnosis system can be used to characterize complex phenotypes and to construct a disease-drug connectivity map.

Progranulin levels in blood in Alzheimer's disease and mild cognitive impairment.

PubMed

Cooper, Yonatan A; Nachun, Daniel; Dokuru, Deepika; Yang, Zhongan; Karydas, Anna M; Serrero, Ginette; Yue, Binbin; Boxer, Adam L; Miller, Bruce L; Coppola, Giovanni

2018-05-01

Changes in progranulin ( GRN ) expression have been hypothesized to alter risk for Alzheimer's disease (AD). We investigated the relationship between GRN expression in peripheral blood and clinical diagnosis of AD and mild cognitive impairment (MCI). Peripheral blood progranulin gene expression was measured, using microarrays from Alzheimer's ( n = 186), MCI ( n = 118), and control ( n = 204) subjects from the University of California San Francisco Memory and Aging Center (UCSF-MAC) and two independent published series (AddNeuroMed and ADNI). GRN gene expression was correlated with clinical, demographic, and genetic data, including APOE haplotype and the GRN rs5848 single-nucleotide polymorphism. Finally, we assessed progranulin protein levels, using enzyme-linked immunosorbent assay, and methylation status using methylation microarrays. We observed an increase in blood progranulin gene expression and a decrease in GRN promoter methylation in males ( P = 0.007). Progranulin expression was 13% higher in AD and MCI patients compared with controls in the UCSF-MAC cohort ( F 2,505 = 10.41, P = 3.72*10 -5 ). This finding was replicated in the AddNeuroMed ( F 2,271 = 17.9, P = 4.83*10 -8 ) but not the ADNI series. The rs5848 SNP (T-allele) predicted decreased blood progranulin gene expression ( P = 0.03). The APOE4 haplotype was positively associated with progranulin expression independent of diagnosis ( P = 0.04). Finally, we did not identify differences in plasma progranulin protein levels or gene methylation between diagnostic categories. Progranulin mRNA is elevated in peripheral blood of patients with AD and MCI and its expression is associated with numerous genetic and demographic factors. These data suggest a role in the pathogenesis of neurodegenerative dementias besides frontotemporal dementia.

Back to basics: pBR322 and protein expression systems in E. coli.

PubMed

Balbás, Paulina; Bolívar, Francisco

2004-01-01

The extensive variety of plasmid-based expression systems in E. coli resulted from the fact that there is no single strategy for achieving maximal expression of every cloned gene. Although a number of strategies have been implemented to deal with problems associated to gene transcription and translation, protein folding, secretion, location, posttranslational modifications, particularities of different strains, and the like and more integrated processes have been developed, the basic plasmid-borne elements and their interaction with the particular host strain will influence the overall expression system and final productivity. Plasmid vector pBR322 is a well-established multipurpose cloning vector in laboratories worldwide, and a large number of derivatives have been created for specific applications and research purposes, including gene expression in its natural host, E. coli, and few other bacteria. The early characterization of the molecule, including its nucleotide sequence, replication and maintenance mechanisms, and determination of its coding regions, accounted for its success, not only as a universal cloning vector, but also as a provider of genes and an origin of replication for other intraspecies vectors. Since the publication of the aforementioned reviews, novel discoveries pertaining to these issues have appeared in the literature that deepen the understanding of the plasmid's features, behavior, and impact in gene expression systems, as well as some important strain characteristics that affect plasmid replication and stability. The objectives of this review include updating and discussing the new information about (1) the replication and maintenance of pBR322; (2) the host-related modulation mechanisms of plasmid replication; (3) the effects of growth rate on replication control, stability, and recombinant gene expression; (4) ways for plasmid amplification and elimination. Finally, (5) a summary of novel ancillary studies about pBR322 is presented.

Nur77 coordinately regulates expression of genes linked to glucose metabolism in skeletal muscle.

PubMed

Chao, Lily C; Zhang, Zidong; Pei, Liming; Saito, Tsugumichi; Tontonoz, Peter; Pilch, Paul F

2007-09-01

Innervation is important for normal metabolism in skeletal muscle, including insulin-sensitive glucose uptake. However, the transcription factors that transduce signals from the neuromuscular junction to the nucleus and affect changes in metabolic gene expression are not well defined. We demonstrate here that the orphan nuclear receptor Nur77 is a regulator of gene expression linked to glucose utilization in muscle. In vivo, Nur77 is preferentially expressed in glycolytic compared with oxidative muscle and is responsive to beta-adrenergic stimulation. Denervation of rat muscle compromises expression of Nur77 in parallel with that of numerous genes linked to glucose metabolism, including glucose transporter 4 and genes involved in glycolysis, glycogenolysis, and the glycerophosphate shuttle. Ectopic expression of Nur77, either in rat muscle or in C2C12 muscle cells, induces expression of a highly overlapping set of genes, including glucose transporter 4, muscle phosphofructokinase, and glycogen phosphorylase. Furthermore, selective knockdown of Nur77 in rat muscle by small hairpin RNA or genetic deletion of Nur77 in mice reduces the expression of a battery of genes involved in skeletal muscle glucose utilization in vivo. Finally, we show that Nur77 binds the promoter regions of multiple genes involved in glucose metabolism in muscle. These results identify Nur77 as a potential mediator of neuromuscular signaling in the control of metabolic gene expression.

Nur77 coordinately regulates expression of genes linked to glucose metabolism in skeletal muscle

PubMed Central

Chao, Lily C.; Zhang, Zidong; Pei, Liming; Saito, Tsugumichi; Tontonoz, Peter; Pilch, Paul F.

2008-01-01

Innervation is important for normal metabolism in skeletal muscle, including insulin-sensitive glucose uptake. However, the transcription factors that transduce signals from the neuromuscular junction to the nucleus and affect changes in metabolic gene expression are not well defined. We demonstrate here that the orphan nuclear receptor Nur77 is a regulator of gene expression linked to glucose utilization in muscle. In vivo, Nur77 is preferentially expressed in glycolytic compared to oxidative muscle and is responsive to β-adrenergic stimulation. Denervation of rat muscle compromises expression of Nur77 in parallel with that of numerous genes linked to glucose metabolism, including GLUT4 and genes involved in glycolysis, glycogenolysis, and the glycerophosphate shuttle. Ectopic expression of Nur77, either in rat muscle or in C2C12 muscle cells, induces expression of a highly overlapping set of genes, including GLUT4, muscle phosphofructokinase, and glycogen phosphorylase. Furthermore, selective knockdown of Nur77 in rat muscle by shRNA or genetic deletion of Nur77 in mice reduces the expression of a battery of genes involved in skeletal muscle glucose utilization in vivo. Finally, we show that Nur77 binds the promoter regions of multiple innervation-dependent genes in muscle. These results identify Nur77 as a potential mediator of neuromuscular signaling in the control of metabolic gene expression. PMID:17550977

Faster-X Evolution of Gene Expression in Drosophila

PubMed Central

Meisel, Richard P.; Malone, John H.; Clark, Andrew G.

2012-01-01

DNA sequences on X chromosomes often have a faster rate of evolution when compared to similar loci on the autosomes, and well articulated models provide reasons why the X-linked mode of inheritance may be responsible for the faster evolution of X-linked genes. We analyzed microarray and RNA–seq data collected from females and males of six Drosophila species and found that the expression levels of X-linked genes also diverge faster than autosomal gene expression, similar to the “faster-X” effect often observed in DNA sequence evolution. Faster-X evolution of gene expression was recently described in mammals, but it was limited to the evolutionary lineages shortly following the creation of the therian X chromosome. In contrast, we detect a faster-X effect along both deep lineages and those on the tips of the Drosophila phylogeny. In Drosophila males, the dosage compensation complex (DCC) binds the X chromosome, creating a unique chromatin environment that promotes the hyper-expression of X-linked genes. We find that DCC binding, chromatin environment, and breadth of expression are all predictive of the rate of gene expression evolution. In addition, estimates of the intraspecific genetic polymorphism underlying gene expression variation suggest that X-linked expression levels are not under relaxed selective constraints. We therefore hypothesize that the faster-X evolution of gene expression is the result of the adaptive fixation of beneficial mutations at X-linked loci that change expression level in cis. This adaptive faster-X evolution of gene expression is limited to genes that are narrowly expressed in a single tissue, suggesting that relaxed pleiotropic constraints permit a faster response to selection. Finally, we present a conceptional framework to explain faster-X expression evolution, and we use this framework to examine differences in the faster-X effect between Drosophila and mammals. PMID:23071459

Gene selection for tumor classification using neighborhood rough sets and entropy measures.

PubMed

Chen, Yumin; Zhang, Zunjun; Zheng, Jianzhong; Ma, Ying; Xue, Yu

2017-03-01

With the development of bioinformatics, tumor classification from gene expression data becomes an important useful technology for cancer diagnosis. Since a gene expression data often contains thousands of genes and a small number of samples, gene selection from gene expression data becomes a key step for tumor classification. Attribute reduction of rough sets has been successfully applied to gene selection field, as it has the characters of data driving and requiring no additional information. However, traditional rough set method deals with discrete data only. As for the gene expression data containing real-value or noisy data, they are usually employed by a discrete preprocessing, which may result in poor classification accuracy. In this paper, we propose a novel gene selection method based on the neighborhood rough set model, which has the ability of dealing with real-value data whilst maintaining the original gene classification information. Moreover, this paper addresses an entropy measure under the frame of neighborhood rough sets for tackling the uncertainty and noisy of gene expression data. The utilization of this measure can bring about a discovery of compact gene subsets. Finally, a gene selection algorithm is designed based on neighborhood granules and the entropy measure. Some experiments on two gene expression data show that the proposed gene selection is an effective method for improving the accuracy of tumor classification. Copyright © 2017 Elsevier Inc. All rights reserved.

Expression of TaCYP78A3, a gene encoding cytochrome P450 CYP78A3 protein in wheat (Triticum aestivum L.), affects seed size.

PubMed

Ma, Meng; Wang, Qian; Li, Zhanjie; Cheng, Huihui; Li, Zhaojie; Liu, Xiangli; Song, Weining; Appels, Rudi; Zhao, Huixian

2015-07-01

Several studies have described quantitative trait loci (QTL) for seed size in wheat, but the relevant genes and molecular mechanisms remain largely unknown. Here we report the functional characterization of the wheat TaCYP78A3 gene and its effect on seed size. TaCYP78A3 encoded wheat cytochrome P450 CYP78A3, and was specifically expressed in wheat reproductive organs. TaCYP78A3 activity was positively correlated with the final seed size. Its silencing caused a reduction of cell number in the seed coat, resulting in an 11% decrease in wheat seed size, whereas TaCYP78A3 over-expression induced production of more cells in the seed coat, leading to an 11-48% increase in Arabidopsis seed size. In addition, the cell number in the final seed coat was determined by the TaCYP78A3 expression level, which affected the extent of integument cell proliferation in the developing ovule and seed. Unfortunately, TaCYP78A3 over-expression in Arabidopsis caused a reduced seed set due to an ovule developmental defect. Moreover, TaCYP78A3 over-expression affected embryo development by promoting embryo integument cell proliferation during seed development, which also ultimately affected the final seed size in Arabidopsis. In summary, our results indicated that TaCYP78A3 plays critical roles in influencing seed size by affecting the extent of integument cell proliferation. The present study provides direct evidence that TaCYP78A3 affects seed size in wheat, and contributes to an understanding of the cellular basis of the gene influencing seed development. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

Hox genes and chordate evolution.

PubMed

Holland, P W; Garcia-Fernàndez, J

1996-02-01

Hox genes are implicated in the control of axial patterning during embryonic development of many, perhaps all, animals. Here we review recent data on Hox gene diversity, genomic organization, and embryonic expression in chordates (including tunicates, amphioxus, hagfish, lampreys, teleosts) plus their putative sister group, the hemichordates. We consider the potential of comparative Hox gene data to resolve some outstanding controversies in chordate phylogeny. The use of Hox gene expression patterns to identify homologies between body plans both within the vertebrates and between the chordate subphyla is also discussed. Homology between the vertebrate hindbrain and an extensive region of amphioxus neural tube is suggested by comparison of Hox-3 homologues and strengthened by new data on amphioxus Hox-1 gene expression reported here. Finally, we give two examples of how Hox genes are giving glimpses into chordate developmental evolution. The first relates changes in Hox gene expression to transposition of vertebral of vertebral identities; the second describes a correlation between vertebrate origins and Hox gene cluster duplication. We suggest that the simultaneous duplication of many classes of genes, often interacting in gene networks, allowed the elaboration of new developmental control mechanisms at vertebrate origins.

Population Level Purifying Selection and Gene Expression Shape Subgenome Evolution in Maize.

PubMed

Pophaly, Saurabh D; Tellier, Aurélien

2015-12-01

The maize ancestor experienced a recent whole-genome duplication (WGD) followed by gene erosion which generated two subgenomes, the dominant subgenome (maize1) experiencing fewer deletions than maize2. We take advantage of available extensive polymorphism and gene expression data in maize to study purifying selection and gene expression divergence between WGD retained paralog pairs. We first report a strong correlation in nucleotide diversity between duplicate pairs, except for upstream regions. We then show that maize1 genes are under stronger purifying selection than maize2. WGD retained genes have higher gene dosage and biased Gene Ontologies consistent with previous studies. The relative gene expression of paralogs across tissues demonstrates that 98% of duplicate pairs have either subfunctionalized in a tissuewise manner or have diverged consistently in their expression thereby preventing functional complementation. Tissuewise subfunctionalization seems to be a hallmark of transcription factors, whereas consistent repression occurs for macromolecular complexes. We show that dominant gene expression is a strong determinant of the strength of purifying selection, explaining the inferred stronger negative selection on maize1 genes. We propose a novel expression-based classification of duplicates which is more robust to explain observed polymorphism patterns than the subgenome location. Finally, upstream regions of repressed genes exhibit an enrichment in transposable elements which indicates a possible mechanism for expression divergence. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Differentially Coexpressed Disease Gene Identification Based on Gene Coexpression Network.

PubMed

Jiang, Xue; Zhang, Han; Quan, Xiongwen

2016-01-01

Screening disease-related genes by analyzing gene expression data has become a popular theme. Traditional disease-related gene selection methods always focus on identifying differentially expressed gene between case samples and a control group. These traditional methods may not fully consider the changes of interactions between genes at different cell states and the dynamic processes of gene expression levels during the disease progression. However, in order to understand the mechanism of disease, it is important to explore the dynamic changes of interactions between genes in biological networks at different cell states. In this study, we designed a novel framework to identify disease-related genes and developed a differentially coexpressed disease-related gene identification method based on gene coexpression network (DCGN) to screen differentially coexpressed genes. We firstly constructed phase-specific gene coexpression network using time-series gene expression data and defined the conception of differential coexpression of genes in coexpression network. Then, we designed two metrics to measure the value of gene differential coexpression according to the change of local topological structures between different phase-specific networks. Finally, we conducted meta-analysis of gene differential coexpression based on the rank-product method. Experimental results demonstrated the feasibility and effectiveness of DCGN and the superior performance of DCGN over other popular disease-related gene selection methods through real-world gene expression data sets.

Immune gene expression for diverse haemocytes derived from pacific white shrimp, Litopenaeus vannamei.

PubMed

Yang, Chih-Chiu; Lu, Chung-Lun; Chen, Sherwin; Liao, Wen-Liang; Chen, Shiu-Nan

2015-05-01

In this study, diverse haemocytes from Pacific white shrimp Litopenaeus vannamei were spread by flow cytometer sorting system. Using the two commonly flow cytometric parameters FSC and SSC, the haemocytes could be divided into three populations. Microscopy observation of L. vannamei haemocytes in anticoagulant buffer revealed three morphologically distinct cell types designated as granular cell, hyaline cell and semigranular cell. Immune genes, which includes prophenoloxidase (proPO), lipopolysaccharide-β-glucan binding protein (LGBP), peroxinectin, crustin, lysozyme, penaeid-3a and transglutaminase (TGase), expressed from different haemocyte were analysed by quantitative real time PCR (qPCR). Results from the mRNA expression was estimated by relative level of each gene to β-actin gene. Finally, the seven genes could be grouped by their dominant expression sites. ProPO, LGBP and peroxinectin were highly expressed in granular cells, while LGBP, crustin, lysozyme and P-3a were highly expressed in semigranular cells and TGase was highly expressed in hyaline cells. In this study, L. vannamei haemocytes were firstly grouped into three different types and the immune related genes expression in grouped haemocytes were estimated. Copyright © 2015 Elsevier Ltd. All rights reserved.

Brain region-specific gene expression changes after chronic intermittent ethanol exposure and early withdrawal in C57BL/6J mice

PubMed Central

Melendez, Roberto I.; McGinty, Jacqueline F.; Kalivas, Peter W.; Becker, Howard C.

2014-01-01

Neuroadaptations that participate in the ontogeny of alcohol dependence are likely a result of altered gene expression in various brain regions. The present study investigated brain region-specific changes in the pattern and magnitude of gene expression immediately following chronic intermittent ethanol (CIE) exposure and 8 hours following final ethanol exposure [i.e. early withdrawal (EWD)]. High-density oligonucleotide microarrays (Affymetrix 430A 2.0, Affymetrix, Santa Clara, CA, USA) and bioinformatics analysis were used to characterize gene expression and function in the prefrontal cortex (PFC), hippocampus (HPC) and nucleus accumbens (NAc) of C57BL/6J mice (Jackson Laboratories, Bar Harbor, ME, USA). Gene expression levels were determined using gene chip robust multi-array average followed by statistical analysis of microarrays and validated by quantitative real-time reverse transcription polymerase chain reaction and Western blot analysis. Results indicated that immediately following CIE exposure, changes in gene expression were strikingly greater in the PFC (284 genes) compared with the HPC (16 genes) and NAc (32 genes). Bioinformatics analysis revealed that most of the transcriptionally responsive genes in the PFC were involved in Ras/MAPK signaling, notch signaling or ubiquitination. In contrast, during EWD, changes in gene expression were greatest in the HPC (139 genes) compared with the PFC (four genes) and NAc (eight genes). The most transcriptionally responsive genes in the HPC were involved in mRNA processing or actin dynamics. Of the few genes detected in the NAc, the most representatives were involved in circadian rhythms. Overall, these findings indicate that brain region-specific and time-dependent neuroadaptive alterations in gene expression play an integral role in the development of alcohol dependence and withdrawal. PMID:21812870

A multi-strategy approach to informative gene identification from gene expression data.

PubMed

Liu, Ziying; Phan, Sieu; Famili, Fazel; Pan, Youlian; Lenferink, Anne E G; Cantin, Christiane; Collins, Catherine; O'Connor-McCourt, Maureen D

2010-02-01

An unsupervised multi-strategy approach has been developed to identify informative genes from high throughput genomic data. Several statistical methods have been used in the field to identify differentially expressed genes. Since different methods generate different lists of genes, it is very challenging to determine the most reliable gene list and the appropriate method. This paper presents a multi-strategy method, in which a combination of several data analysis techniques are applied to a given dataset and a confidence measure is established to select genes from the gene lists generated by these techniques to form the core of our final selection. The remainder of the genes that form the peripheral region are subject to exclusion or inclusion into the final selection. This paper demonstrates this methodology through its application to an in-house cancer genomics dataset and a public dataset. The results indicate that our method provides more reliable list of genes, which are validated using biological knowledge, biological experiments, and literature search. We further evaluated our multi-strategy method by consolidating two pairs of independent datasets, each pair is for the same disease, but generated by different labs using different platforms. The results showed that our method has produced far better results.

Major Shifts in Glial Regional Identity Are a Transcriptional Hallmark of Human Brain Aging.

PubMed

Soreq, Lilach; Rose, Jamie; Soreq, Eyal; Hardy, John; Trabzuni, Daniah; Cookson, Mark R; Smith, Colin; Ryten, Mina; Patani, Rickie; Ule, Jernej

2017-01-10

Gene expression studies suggest that aging of the human brain is determined by a complex interplay of molecular events, although both its region- and cell-type-specific consequences remain poorly understood. Here, we extensively characterized aging-altered gene expression changes across ten human brain regions from 480 individuals ranging in age from 16 to 106 years. We show that astrocyte- and oligodendrocyte-specific genes, but not neuron-specific genes, shift their regional expression patterns upon aging, particularly in the hippocampus and substantia nigra, while the expression of microglia- and endothelial-specific genes increase in all brain regions. In line with these changes, high-resolution immunohistochemistry demonstrated decreased numbers of oligodendrocytes and of neuronal subpopulations in the aging brain cortex. Finally, glial-specific genes predict age with greater precision than neuron-specific genes, thus highlighting the need for greater mechanistic understanding of neuron-glia interactions in aging and late-life diseases. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Noise in gene expression is coupled to growth rate.

PubMed

Keren, Leeat; van Dijk, David; Weingarten-Gabbay, Shira; Davidi, Dan; Jona, Ghil; Weinberger, Adina; Milo, Ron; Segal, Eran

2015-12-01

Genetically identical cells exposed to the same environment display variability in gene expression (noise), with important consequences for the fidelity of cellular regulation and biological function. Although population average gene expression is tightly coupled to growth rate, the effects of changes in environmental conditions on expression variability are not known. Here, we measure the single-cell expression distributions of approximately 900 Saccharomyces cerevisiae promoters across four environmental conditions using flow cytometry, and find that gene expression noise is tightly coupled to the environment and is generally higher at lower growth rates. Nutrient-poor conditions, which support lower growth rates, display elevated levels of noise for most promoters, regardless of their specific expression values. We present a simple model of noise in expression that results from having an asynchronous population, with cells at different cell-cycle stages, and with different partitioning of the cells between the stages at different growth rates. This model predicts non-monotonic global changes in noise at different growth rates as well as overall higher variability in expression for cell-cycle-regulated genes in all conditions. The consistency between this model and our data, as well as with noise measurements of cells growing in a chemostat at well-defined growth rates, suggests that cell-cycle heterogeneity is a major contributor to gene expression noise. Finally, we identify gene and promoter features that play a role in gene expression noise across conditions. Our results show the existence of growth-related global changes in gene expression noise and suggest their potential phenotypic implications. © 2015 Keren et al.; Published by Cold Spring Harbor Laboratory Press.

Noise in gene expression is coupled to growth rate

PubMed Central

Keren, Leeat; van Dijk, David; Weingarten-Gabbay, Shira; Davidi, Dan; Jona, Ghil; Weinberger, Adina; Milo, Ron; Segal, Eran

2015-01-01

Genetically identical cells exposed to the same environment display variability in gene expression (noise), with important consequences for the fidelity of cellular regulation and biological function. Although population average gene expression is tightly coupled to growth rate, the effects of changes in environmental conditions on expression variability are not known. Here, we measure the single-cell expression distributions of approximately 900 Saccharomyces cerevisiae promoters across four environmental conditions using flow cytometry, and find that gene expression noise is tightly coupled to the environment and is generally higher at lower growth rates. Nutrient-poor conditions, which support lower growth rates, display elevated levels of noise for most promoters, regardless of their specific expression values. We present a simple model of noise in expression that results from having an asynchronous population, with cells at different cell-cycle stages, and with different partitioning of the cells between the stages at different growth rates. This model predicts non-monotonic global changes in noise at different growth rates as well as overall higher variability in expression for cell-cycle–regulated genes in all conditions. The consistency between this model and our data, as well as with noise measurements of cells growing in a chemostat at well-defined growth rates, suggests that cell-cycle heterogeneity is a major contributor to gene expression noise. Finally, we identify gene and promoter features that play a role in gene expression noise across conditions. Our results show the existence of growth-related global changes in gene expression noise and suggest their potential phenotypic implications. PMID:26355006

Identification of differentially expressed genes in cucumber (Cucumis sativus L.) root under waterlogging stress by digital gene expression profile.

PubMed

Qi, Xiao-Hua; Xu, Xue-Wen; Lin, Xiao-Jian; Zhang, Wen-Jie; Chen, Xue-Hao

2012-03-01

High-throughput tag-sequencing (Tag-seq) analysis based on the Solexa Genome Analyzer platform was applied to analyze the gene expression profiling of cucumber plant at 5 time points over a 24h period of waterlogging treatment. Approximately 5.8 million total clean sequence tags per library were obtained with 143013 distinct clean tag sequences. Approximately 23.69%-29.61% of the distinct clean tags were mapped unambiguously to the unigene database, and 53.78%-60.66% of the distinct clean tags were mapped to the cucumber genome database. Analysis of the differentially expressed genes revealed that most of the genes were down-regulated in the waterlogging stages, and the differentially expressed genes mainly linked to carbon metabolism, photosynthesis, reactive oxygen species generation/scavenging, and hormone synthesis/signaling. Finally, quantitative real-time polymerase chain reaction using nine genes independently verified the tag-mapped results. This present study reveals the comprehensive mechanisms of waterlogging-responsive transcription in cucumber. Copyright © 2011 Elsevier Inc. All rights reserved.

Integrating Gene Expression with Summary Association Statistics to Identify Genes Associated with 30 Complex Traits.

PubMed

Mancuso, Nicholas; Shi, Huwenbo; Goddard, Pagé; Kichaev, Gleb; Gusev, Alexander; Pasaniuc, Bogdan

2017-03-02

Although genome-wide association studies (GWASs) have identified thousands of risk loci for many complex traits and diseases, the causal variants and genes at these loci remain largely unknown. Here, we introduce a method for estimating the local genetic correlation between gene expression and a complex trait and utilize it to estimate the genetic correlation due to predicted expression between pairs of traits. We integrated gene expression measurements from 45 expression panels with summary GWAS data to perform 30 multi-tissue transcriptome-wide association studies (TWASs). We identified 1,196 genes whose expression is associated with these traits; of these, 168 reside more than 0.5 Mb away from any previously reported GWAS significant variant. We then used our approach to find 43 pairs of traits with significant genetic correlation at the level of predicted expression; of these, eight were not found through genetic correlation at the SNP level. Finally, we used bi-directional regression to find evidence that BMI causally influences triglyceride levels and that triglyceride levels causally influence low-density lipoprotein. Together, our results provide insight into the role of gene expression in the susceptibility of complex traits and diseases. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

A 3,000-loci transcription map of chromosome 3B unravels the structural and functional features of gene islands in hexaploid wheat.

PubMed

Rustenholz, Camille; Choulet, Frédéric; Laugier, Christel; Safár, Jan; Simková, Hana; Dolezel, Jaroslav; Magni, Federica; Scalabrin, Simone; Cattonaro, Federica; Vautrin, Sonia; Bellec, Arnaud; Bergès, Hélène; Feuillet, Catherine; Paux, Etienne

2011-12-01

To improve our understanding of the organization and regulation of the wheat (Triticum aestivum) gene space, we established a transcription map of a wheat chromosome (3B) by hybridizing a newly developed wheat expression microarray with bacterial artificial chromosome pools from a new version of the 3B physical map as well as with cDNA probes derived from 15 RNA samples. Mapping data for almost 3,000 genes showed that the gene space spans the whole chromosome 3B with a 2-fold increase of gene density toward the telomeres due to an increase in the number of genes in islands. Comparative analyses with rice (Oryza sativa) and Brachypodium distachyon revealed that these gene islands are composed mainly of genes likely originating from interchromosomal gene duplications. Gene Ontology and expression profile analyses for the 3,000 genes located along the chromosome revealed that the gene islands are enriched significantly in genes sharing the same function or expression profile, thereby suggesting that genes in islands acquired shared regulation during evolution. Only a small fraction of these clusters of cofunctional and coexpressed genes was conserved with rice and B. distachyon, indicating a recent origin. Finally, genes with the same expression profiles in remote islands (coregulation islands) were identified suggesting long-distance regulation of gene expression along the chromosomes in wheat.

Computational genomic analysis of PARK7 interactome reveals high BBS1 gene expression as a prognostic factor favoring survival in malignant pleural mesothelioma.

PubMed

Vavougios, Georgios D; Solenov, Evgeniy I; Hatzoglou, Chrissi; Baturina, Galina S; Katkova, Liubov E; Molyvdas, Paschalis Adam; Gourgoulianis, Konstantinos I; Zarogiannis, Sotirios G

2015-10-01

The aim of our study was to assess the differential gene expression of Parkinson protein 7 (PARK7) interactome in malignant pleural mesothelioma (MPM) using data mining techniques to identify novel candidate genes that may play a role in the pathogenicity of MPM. We constructed the PARK7 interactome using the ConsensusPathDB database. We then interrogated the Oncomine Cancer Microarray database using the Gordon Mesothelioma Study, for differential gene expression of the PARK7 interactome. In ConsensusPathDB, 38 protein interactors of PARK7 were identified. In the Gordon Mesothelioma Study, 34 of them were assessed out of which SUMO1, UBC3, KIAA0101, HDAC2, DAXX, RBBP4, BBS1, NONO, RBBP7, HTRA2, and STUB1 were significantly overexpressed whereas TRAF6 and MTA2 were significantly underexpressed in MPM patients (network 2). Furthermore, Kaplan-Meier analysis revealed that MPM patients with high BBS1 expression had a median overall survival of 16.5 vs. 8.7 mo of those that had low expression. For validation purposes, we performed a meta-analysis in Oncomine database in five sarcoma datasets. Eight network 2 genes (KIAA0101, HDAC2, SUMO1, RBBP4, NONO, RBBP7, HTRA2, and MTA2) were significantly differentially expressed in an array of 18 different sarcoma types. Finally, Gene Ontology annotation enrichment analysis revealed significant roles of the PARK7 interactome in NuRD, CHD, and SWI/SNF protein complexes. In conclusion, we identified 13 novel genes differentially expressed in MPM, never reported before. Among them, BBS1 emerged as a novel predictor of overall survival in MPM. Finally, we identified that PARK7 interactome is involved in novel pathways pertinent in MPM disease. Copyright © 2015 the American Physiological Society.

High final energy of gallium arsenide laser increases MyoD gene expression during the intermediate phase of muscle regeneration after cryoinjury in rats.

PubMed

Santos, Caroline Pereira; Aguiar, Andreo Fernando; Giometti, Ines Cristina; Mariano, Thaoan Bruno; de Freitas, Carlos Eduardo Assumpção; Nai, Gisele Alborghetti; de Freitas, Selma Zambelli; Pai-Silva, Maeli Dal; Pacagnelli, Francis Lopes

2018-05-01

The aim of this study was to determine the effects of gallium arsenide (GaAs) laser on IGF-I, MyoD, MAFbx, and TNF-α gene expression during the intermediate phase of muscle regeneration after cryoinjury 21 Wistar rats were divided into three groups (n = 7 per group): untreated with no injury (control group), cryoinjury without GaAs (injured group), and cryoinjury with GaAs (GaAs-injured group). The cryoinjury was induced in the central region of the tibialis anterior muscle (TA). The region injured was irradiated once a day during 14 days using GaAs laser (904 nm; spot size 0.035 cm 2 , output power 50 mW; energy density 69 J cm -2 ; exposure time 4 s per point; final energy 4.8 J). Twenty-four hours after the last application, the right and left TA muscles were collected for histological (collagen content) and molecular (gene expression of IGF-I, MyoD, MAFbx, and TNF-α) analyses, respectively. Data were analyzed using one-way ANOVA at P < 0.05. There were no significant (P > 0.05) differences in collagen density and IGF-I gene expression in all experimental groups. There were similar (P < 0.05) decreases in MAFbx and TNF-α gene expression in the injured and GaAs-injured groups, compared to control group. The MyoD gene expression increased (P = 0.008) in the GaAs-injured group, but not in the injured group (P = 0.338), compared to control group. GaAs laser therapy had a positive effect on MyoD gene expression, but not IGF-I, MAFbx, and TNF-α, during intermediary phases (14 days post-injury) of muscle repair.

Gene expression profile change and growth inhibition in Drosophila larvae treated with azadirachtin.

PubMed

Lai, Duo; Jin, Xiaoyong; Wang, Hao; Yuan, Mei; Xu, Hanhong

2014-09-20

Azadirachtin is a botanical insecticide that affects various biological processes. The effects of azadirachtin on the digital gene expression profile and growth inhibition in Drosophila larvae have not been investigated. In this study, we applied high-throughput sequencing technology to detect the differentially expressed genes of Drosophila larvae regulated by azadirachtin. A total of 15,322 genes were detected, and 28 genes were found to be significantly regulated by azadirachtin. Biological process and pathway analysis showed that azadirachtin affected starch and sucrose metabolism, defense response, signal transduction, instar larval or pupal development, and chemosensory behavior processes. The genes regulated by azadirachtin were mainly enriched in starch and sucrose metabolism. This study provided a general digital gene expression profile of dysregulated genes in response to azadirachtin and showed that azadirachtin provoked potent growth inhibitory effects in Drosophila larvae by regulating the genes of cuticular protein, amylase, and odorant-binding protein. Finally, we propose a potential mechanism underlying the dysregulation of the insulin/insulin-like growth factor signaling pathway by azadirachtin. Copyright © 2014 Elsevier B.V. All rights reserved.

Selection of Reference Genes for Expression Studies of Xenobiotic Adaptation in Tetranychus urticae.

PubMed

Morales, Mariany Ashanty; Mendoza, Bianca Marie; Lavine, Laura Corley; Lavine, Mark Daniel; Walsh, Douglas Bruce; Zhu, Fang

2016-01-01

Quantitative real-time PCR (qRT-PCR) is an extensively used, high-throughput method to analyze transcriptional expression of genes of interest. An appropriate normalization strategy with reliable reference genes is required for calculating gene expression across diverse experimental conditions. In this study, we aim to identify the most stable reference genes for expression studies of xenobiotic adaptation in Tetranychus urticae, an extremely polyphagous herbivore causing significant yield reduction of agriculture. We chose eight commonly used housekeeping genes as candidates. The qRT-PCR expression data for these genes were evaluated from seven populations: a susceptible and three acaricide resistant populations feeding on lima beans, and three other susceptible populations which had been shifted host from lima beans to three other plant species. The stability of the candidate reference genes was then assessed using four different algorithms (comparative ΔCt method, geNorm, NormFinder, and BestKeeper). Additionally, we used an online web-based tool (RefFinder) to assign an overall final rank for each candidate gene. Our study found that CycA and Rp49 are best for investigating gene expression in acaricide susceptible and resistant populations. GAPDH, Rp49, and Rpl18 are best for host plant shift studies. And GAPDH and Rp49 were the most stable reference genes when investigating gene expression under changes in both experimental conditions. These results will facilitate research in revealing molecular mechanisms underlying the xenobiotic adaptation of this notorious agricultural pest.

Selection of Reference Genes for Expression Studies of Xenobiotic Adaptation in Tetranychus urticae

PubMed Central

Morales, Mariany Ashanty; Mendoza, Bianca Marie; Lavine, Laura Corley; Lavine, Mark Daniel; Walsh, Douglas Bruce; Zhu, Fang

2016-01-01

Quantitative real-time PCR (qRT-PCR) is an extensively used, high-throughput method to analyze transcriptional expression of genes of interest. An appropriate normalization strategy with reliable reference genes is required for calculating gene expression across diverse experimental conditions. In this study, we aim to identify the most stable reference genes for expression studies of xenobiotic adaptation in Tetranychus urticae, an extremely polyphagous herbivore causing significant yield reduction of agriculture. We chose eight commonly used housekeeping genes as candidates. The qRT-PCR expression data for these genes were evaluated from seven populations: a susceptible and three acaricide resistant populations feeding on lima beans, and three other susceptible populations which had been shifted host from lima beans to three other plant species. The stability of the candidate reference genes was then assessed using four different algorithms (comparative ΔCt method, geNorm, NormFinder, and BestKeeper). Additionally, we used an online web-based tool (RefFinder) to assign an overall final rank for each candidate gene. Our study found that CycA and Rp49 are best for investigating gene expression in acaricide susceptible and resistant populations. GAPDH, Rp49, and Rpl18 are best for host plant shift studies. And GAPDH and Rp49 were the most stable reference genes when investigating gene expression under changes in both experimental conditions. These results will facilitate research in revealing molecular mechanisms underlying the xenobiotic adaptation of this notorious agricultural pest. PMID:27570487

Successful pod infections by Moniliophthora roreri result in differential Theobroma cacao gene expression depending on the clone's level of tolerance.

PubMed

Ali, Shahin S; Melnick, Rachel L; Crozier, Jayne; Phillips-Mora, Wilberth; Strem, Mary D; Shao, Jonathan; Zhang, Dapeng; Sicher, Richard; Meinhardt, Lyndel; Bailey, Bryan A

2014-09-01

An understanding of the tolerance mechanisms of Theobroma cacao used against Moniliophthora roreri, the causal agent of frosty pod rot, is important for the generation of stable disease-tolerant clones. A comparative view was obtained of transcript populations of infected pods from two susceptible and two tolerant clones using RNA sequence (RNA-Seq) analysis. A total of 3009 transcripts showed differential expression among clones. KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway analysis of differentially expressed genes indicated shifts in 152 different metabolic pathways between the tolerant and susceptible clones. Real-time quantitative reverse transcription polymerase chain reaction (real-time qRT-PCR) analyses of 36 genes verified the differential expression. Regression analysis validated a uniform progression in gene expression in association with infection levels and fungal loads in the susceptible clones. Expression patterns observed in the susceptible clones diverged in tolerant clones, with many genes showing higher expression at a low level of infection and fungal load. Principal coordinate analyses of real-time qRT-PCR data separated the gene expression patterns between susceptible and tolerant clones for pods showing malformation. Although some genes were constitutively differentially expressed between clones, most results suggested that defence responses were induced at low fungal load in the tolerant clones. Several elicitor-responsive genes were highly expressed in tolerant clones, suggesting rapid recognition of the pathogen and induction of defence genes. Expression patterns suggested that the jasmonic acid-ethylene- and/or salicylic acid-mediated defence pathways were activated in the tolerant clones, being enhanced by reduced brassinosteroid (BR) biosynthesis and catabolic inactivation of both BR and abscisic acids. Finally, several genes associated with hypersensitive response-like cell death were also induced in tolerant clones. © 2014 BSPP AND JOHN WILEY & SONS LTD.

Global gene expression profiling of brown to white adipose tissue transformation in sheep reveals novel transcriptional components linked to adipose remodeling.

PubMed

Basse, Astrid L; Dixen, Karen; Yadav, Rachita; Tygesen, Malin P; Qvortrup, Klaus; Kristiansen, Karsten; Quistorff, Bjørn; Gupta, Ramneek; Wang, Jun; Hansen, Jacob B

2015-03-19

Large mammals are capable of thermoregulation shortly after birth due to the presence of brown adipose tissue (BAT). The majority of BAT disappears after birth and is replaced by white adipose tissue (WAT). We analyzed the postnatal transformation of adipose in sheep with a time course study of the perirenal adipose depot. We observed changes in tissue morphology, gene expression and metabolism within the first two weeks of postnatal life consistent with the expected transition from BAT to WAT. The transformation was characterized by massively decreased mitochondrial abundance and down-regulation of gene expression related to mitochondrial function and oxidative phosphorylation. Global gene expression profiling demonstrated that the time points grouped into three phases: a brown adipose phase, a transition phase and a white adipose phase. Between the brown adipose and the transition phase 170 genes were differentially expressed, and 717 genes were differentially expressed between the transition and the white adipose phase. Thirty-eight genes were shared among the two sets of differentially expressed genes. We identified a number of regulated transcription factors, including NR1H3, MYC, KLF4, ESR1, RELA and BCL6, which were linked to the overall changes in gene expression during the adipose tissue remodeling. Finally, the perirenal adipose tissue expressed both brown and brite/beige adipocyte marker genes at birth, the expression of which changed substantially over time. Using global gene expression profiling of the postnatal BAT to WAT transformation in sheep, we provide novel insight into adipose tissue plasticity in a large mammal, including identification of novel transcriptional components linked to adipose tissue remodeling. Moreover, our data set provides a useful resource for further studies in adipose tissue plasticity.

Low-rank regularization for learning gene expression programs.

PubMed

Ye, Guibo; Tang, Mengfan; Cai, Jian-Feng; Nie, Qing; Xie, Xiaohui

2013-01-01

Learning gene expression programs directly from a set of observations is challenging due to the complexity of gene regulation, high noise of experimental measurements, and insufficient number of experimental measurements. Imposing additional constraints with strong and biologically motivated regularizations is critical in developing reliable and effective algorithms for inferring gene expression programs. Here we propose a new form of regulation that constrains the number of independent connectivity patterns between regulators and targets, motivated by the modular design of gene regulatory programs and the belief that the total number of independent regulatory modules should be small. We formulate a multi-target linear regression framework to incorporate this type of regulation, in which the number of independent connectivity patterns is expressed as the rank of the connectivity matrix between regulators and targets. We then generalize the linear framework to nonlinear cases, and prove that the generalized low-rank regularization model is still convex. Efficient algorithms are derived to solve both the linear and nonlinear low-rank regularized problems. Finally, we test the algorithms on three gene expression datasets, and show that the low-rank regularization improves the accuracy of gene expression prediction in these three datasets.

Final technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edward DeLong

2011-10-07

Our overarching goals in this project were to: Develop and improve high-throughput sequencing methods and analytical approaches for quantitative analyses of microbial gene expression at the Hawaii Ocean Time Series Station and the Bermuda Atlantic Time Series Station; Conduct field analyses following gene expression patterns in picoplankton microbial communities in general, and Prochlorococcus flow sorted from that community, as they respond to different environmental variables (light, macronutrients, dissolved organic carbon), that are predicted to influence activity, productivity, and carbon cycling; Use the expression analyses of flow sorted Prochlorococcus to identify horizontally transferred genes and gene products, in particular those thatmore » are located in genomic islands and likely to confer habitat-specific fitness advantages; Use the microbial community gene expression data that we generate to gain insights, and test hypotheses, about the variability, genomic context, activity and function of as yet uncharacterized gene products, that appear highly expressed in the environment. We achieved the above goals, and even more over the course of the project. This includes a number of novel methodological developments, as well as the standardization of microbial community gene expression analyses in both field surveys, and experimental modalities. The availability of these methods, tools and approaches is changing current practice in microbial community analyses.« less

Sugar regulation of SUGAR TRANSPORTER PROTEIN 1 (STP1) expression in Arabidopsis thaliana

PubMed Central

Cordoba, Elizabeth; Aceves-Zamudio, Denise Lizeth; Hernández-Bernal, Alma Fabiola; Ramos-Vega, Maricela; León, Patricia

2015-01-01

Sugars regulate the expression of many genes at the transcriptional level. In Arabidopsis thaliana, sugars induce or repress the expression of >1800 genes, including the STP1 (SUGAR TRANSPORTER PROTEIN 1) gene, which encodes an H+/monosaccharide cotransporter. STP1 transcript levels decrease more rapidly after the addition of low concentrations of sugars than the levels of other repressed genes, such as DIN6 (DARK-INDUCED 6). We found that this regulation is exerted at the transcriptional level and is initiated by phosphorylatable sugars. Interestingly, the sugar signal that modulates STP1 expression is transmitted through a HEXOKINASE 1-independent signalling pathway. Finally, analysis of the STP1 5′ regulatory region allowed us to delimit a region of 309bp that contains the cis elements implicated in the glucose regulation of STP1 expression. Putative cis-acting elements involved in this response were identified. PMID:25281700

Dynamic gene expression of Lin-28 during embryonic development in mouse and chicken.

PubMed

Yokoyama, Shigetoshi; Hashimoto, Megumi; Shimizu, Hirohito; Ueno-Kudoh, Hiroe; Uchibe, Kenta; Kimura, Ichiro; Asahara, Hiroshi

2008-02-01

The Caenorhabditis elegans heterochronic gene lin-28 regulates developmental timing in the nematode trunk. We report the dynamic expression patterns of Lin-28 homologues in mouse and chick embryos. Whole mount in situ hybridization revealed specific and intriguing expression patterns of Lin-28 in the developing mouse and chick limb bud. Mouse Lin-28 expression was detected in both the forelimb and hindlimb at E9.5, but disappeared from the forelimb at E10.5, and finally from the forelimb and hindlimb at E11.5. Chicken Lin-28, which was first detected in the limb primordium at stage 15/16, was also downregulated as the stage proceeded. The amino acid sequences of mouse and chicken Lin-28 genes are highly conserved and the similar expression patterns of Lin-28 during limb development in mouse and chicken suggest that this heterochronic gene is also conserved during vertebrate limb development.

Cadmium induces cadmium-tolerant gene expression in the filamentous fungus Trichoderma harzianum.

PubMed

Cacciola, Santa O; Puglisi, Ivana; Faedda, Roberto; Sanzaro, Vincenzo; Pane, Antonella; Lo Piero, Angela R; Evoli, Maria; Petrone, Goffredo

2015-11-01

The filamentous fungus Trichoderma harzianum, strain IMI 393899, was able to grow in the presence of the heavy metals cadmium and mercury. The main objective of this research was to study the molecular mechanisms underlying the tolerance of the fungus T. harzianum to cadmium. The suppression subtractive hybridization (SSH) method was used for the characterization of the genes of T. harzianum implicated in cadmium tolerance compared with those expressed in the response to the stress induced by mercury. Finally, the effects of cadmium exposure were also validated by measuring the expression levels of the putative genes coding for a glucose transporter, a plasma membrane ATPase, a Cd(2+)/Zn(2+) transporter protein and a two-component system sensor histidine kinase YcbA, by real-time-PCR. By using the aforementioned SSH strategy, it was possible to identify 108 differentially expressed genes of the strain IMI 393899 of T. harzianum grown in a mineral substrate with the addition of cadmium. The expressed sequence tags identified by SSH technique were encoding different genes that may be involved in different biological processes, including those associated to primary and secondary metabolism, intracellular transport, transcription factors, cell defence, signal transduction, DNA metabolism, cell growth and protein synthesis. Finally, the results show that in the mechanism of tolerance to cadmium a possible signal transduction pathway could activate a Cd(2+)/Zn(2+) transporter protein and/or a plasma membrane ATPase that could be involved in the compartmentalization of cadmium inside the cell.

The HSV-1 Latency-Associated Transcript Functions to Repress Latent Phase Lytic Gene Expression and Suppress Virus Reactivation from Latently Infected Neurons

PubMed Central

Nicoll, Michael P.; Hann, William; Shivkumar, Maitreyi; Harman, Laura E. R.; Connor, Viv; Coleman, Heather M.; Proença, João T.; Efstathiou, Stacey

2016-01-01

Herpes simplex virus 1 (HSV-1) establishes life-long latent infection within sensory neurons, during which viral lytic gene expression is silenced. The only highly expressed viral gene product during latent infection is the latency-associated transcript (LAT), a non-protein coding RNA that has been strongly implicated in the epigenetic regulation of HSV-1 gene expression. We have investigated LAT-mediated control of latent gene expression using chromatin immunoprecipitation analyses and LAT-negative viruses engineered to express firefly luciferase or β-galactosidase from a heterologous lytic promoter. Whilst we were unable to determine a significant effect of LAT expression upon heterochromatin enrichment on latent HSV-1 genomes, we show that reporter gene expression from latent HSV-1 genomes occurs at a greater frequency in the absence of LAT. Furthermore, using luciferase reporter viruses we have observed that HSV-1 gene expression decreases during long-term latent infection, with a most marked effect during LAT-negative virus infection. Finally, using a fluorescent mouse model of infection to isolate and culture single latently infected neurons, we also show that reactivation occurs at a greater frequency from cultures harbouring LAT-negative HSV-1. Together, our data suggest that the HSV-1 LAT RNA represses HSV-1 gene expression in small populations of neurons within the mouse TG, a phenomenon that directly impacts upon the frequency of reactivation and the maintenance of the transcriptionally active latent reservoir. PMID:27055281

Exploration of new perspectives and limitations in Agrobacterium-mediated gene transfer technology. Final report, June 1, 1992--May 31, 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marton, L.

1996-02-01

Genetic manipulation of plants often involves the introduction of homologous or partly homologous genes. Ectropic introduction of homologous sequences into plant genomes may trigger epigenetic changes, making expression of the genes unpredictable. The main project objective was to examine the feasibility of using Agrobacterium-mediated gene transfer for homologous gene targeting in plants.

Construction of two vectors for gene expression in Trichoderma reesei.

PubMed

Lv, Dandan; Wang, Wei; Wei, Dongzhi

2012-01-01

We report the construction of two filamentous fungi Trichoderma reesei expression vectors, pWEF31 and pWEF32. Both vectors possess the hygromycin phosphotransferase B gene expression cassette and the strong promoter and terminator of the cellobiohydrolase 1 gene (cbh1) from T. reesei. The two newly constructed vectors can be efficiently transformed into T. reesei with Agrobacterium-mediated transformation. The difference between pWEF31 and pWEF32 is that pWEF32 has two longer homologous arms. As a result, pWEF32 easily undergoes homologous recombination. On the other hand, pWEF31 undergoes random recombination. The applicability of both vectors was tested by first generating the expression vectors pWEF31-red and pWEF32-red and then detecting the expression of the DsRed2 gene in T. reesei Rut C30. Additionally, we measured the exo-1,4-β-glucanase activity of the recombinant cells. Our work provides an effective transformation system for homologous and heterologous gene expression and gene knockout in T. reesei. It also provides a method for recombination at a specific chromosomal location. Finally, both vectors will be useful for the large-scale gene expression industry. Copyright © 2011 Elsevier Inc. All rights reserved.

Ion Channel Gene Expression in Lung Adenocarcinoma: Potential Role in Prognosis and Diagnosis

PubMed Central

Ko, Jae-Hong; Gu, Wanjun; Lim, Inja; Bang, Hyoweon; Ko, Eun A.; Zhou, Tong

2014-01-01

Ion channels are known to regulate cancer processes at all stages. The roles of ion channels in cancer pathology are extremely diverse. We systematically analyzed the expression patterns of ion channel genes in lung adenocarcinoma. First, we compared the expression of ion channel genes between normal and tumor tissues in patients with lung adenocarcinoma. Thirty-seven ion channel genes were identified as being differentially expressed between the two groups. Next, we investigated the prognostic power of ion channel genes in lung adenocarcinoma. We assigned a risk score to each lung adenocarcinoma patient based on the expression of the differentially expressed ion channel genes. We demonstrated that the risk score effectively predicted overall survival and recurrence-free survival in lung adenocarcinoma. We also found that the risk scores for ever-smokers were higher than those for never-smokers. Multivariate analysis indicated that the risk score was a significant prognostic factor for survival, which is independent of patient age, gender, stage, smoking history, Myc level, and EGFR/KRAS/ALK gene mutation status. Finally, we investigated the difference in ion channel gene expression between the two major subtypes of non-small cell lung cancer: adenocarcinoma and squamous-cell carcinoma. Thirty ion channel genes were identified as being differentially expressed between the two groups. We suggest that ion channel gene expression can be used to improve the subtype classification in non-small cell lung cancer at the molecular level. The findings in this study have been validated in several independent lung cancer cohorts. PMID:24466154

Vaccine-induced modulation of gene expression in turbot peritoneal cells. A microarray approach.

PubMed

Fontenla, Francisco; Blanco-Abad, Verónica; Pardo, Belén G; Folgueira, Iria; Noia, Manuel; Gómez-Tato, Antonio; Martínez, Paulino; Leiro, José M; Lamas, Jesús

2016-07-01

We used a microarray approach to examine changes in gene expression in turbot peritoneal cells after injection of the fish with vaccines containing the ciliate parasite Philasterides dicentrarchi as antigen and one of the following adjuvants: chitosan-PVMMA microspheres, Freund́s complete adjuvant, aluminium hydroxide gel or Matrix-Q (Isconova, Sweden). We identified 374 genes that were differentially expressed in all groups of fish. Forty-two genes related to tight junctions and focal adhesions and/or actin cytoskeleton were differentially expressed in free peritoneal cells. The profound changes in gene expression related to cell adherence and cytoskeleton may be associated with cell migration and also with the formation of cell-vaccine masses and their attachment to the peritoneal wall. Thirty-five genes related to apoptosis were differentially expressed. Although most of the proteins coded by these genes have a proapoptotic effect, others are antiapoptotic, indicating that both types of signals occur in peritoneal leukocytes of vaccinated fish. Interestingly, many of the genes related to lymphocytes and lymphocyte activity were downregulated in the groups injected with vaccine. We also observed decreased expression of genes related to antigen presentation, suggesting that macrophages (which were abundant in the peritoneal cavity after vaccination) did not express these during the early inflammatory response in the peritoneal cavity. Finally, several genes that participate in the inflammatory response were differentially expressed, and most participated in resolution of inflammation, indicating that an M2 macrophage response is generated in the peritoneal cavity of fish one day post vaccination. Copyright © 2016 Elsevier Ltd. All rights reserved.

Identification of suitable qPCR reference genes in leaves of Brassica oleracea under abiotic stresses.

PubMed

Brulle, Franck; Bernard, Fabien; Vandenbulcke, Franck; Cuny, Damien; Dumez, Sylvain

2014-04-01

Real-time quantitative PCR is nowadays a standard method to study gene expression variations in various samples and experimental conditions. However, to interpret results accurately, data normalization with appropriate reference genes appears to be crucial. The present study describes the identification and the validation of suitable reference genes in Brassica oleracea leaves. Expression stability of eight candidates was tested following drought and cold abiotic stresses by using three different softwares (BestKeeper, NormFinder and geNorm). Four genes (BolC.TUB6, BolC.SAND1, BolC.UBQ2 and BolC.TBP1) emerged as the most stable across the tested conditions. Further gene expression analysis of a drought- and a cold-responsive gene (BolC.DREB2A and BolC.ELIP, respectively), confirmed the stability and the reliability of the identified reference genes when used for normalization in the leaves of B. oleracea. These four genes were finally tested upon a benzene exposure and all appeared to be useful reference genes along this toxicological condition. These results provide a good starting point for future studies involving gene expression measurement on leaves of B. oleracea exposed to environmental modifications.

IDPT: Insights into potential intrinsically disordered proteins through transcriptomic analysis of genes for prostate carcinoma epigenetic data.

PubMed

Mallik, Saurav; Sen, Sagnik; Maulik, Ujjwal

2016-07-15

Involvement of intrinsically disordered proteins (IDPs) with various dreadful diseases like cancer is an interesting research topic. In order to gain novel insights into the regulation of IDPs, in this article, we perform a transcriptomic analysis of mRNAs (genes) for transcripts encoding IDPs on a human multi-omics prostate carcinoma dataset having both gene expression and methylation data. In this regard, firstly the genes that consist of both the expression and methylation data, and that are corresponding to the cancer-related prostate-tissue-specific disordered proteins of MobiDb database, are selected. We apply standard t-test for determining differentially expressed genes as well as differentially methylated genes. A network having these genes and their targeter miRNAs from Diana Tarbase v7.0 database and corresponding Transcription Factors from TRANSFAC and ITFP databases, is then built. Thereafter, we perform literature search, and KEGG pathway and Gene Ontology analyses using DAVID database. Finally, we report several significant potential gene-markers (with the corresponding IDPs) that have inverse relationship between differential expression and methylation patterns, and that are hub genes of the TF-miRNA-gene network. Copyright © 2016 Elsevier B.V. All rights reserved.

The 5th Symposium on Post-Transcriptional Regulation of Plant Gene Expression (PTRoPGE)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karen S. Browning; Marie Petrocek; Bonnie Bartel

2006-06-01

The 5th Symposium on Post-Transcriptional Regulation of Plant Gene Expression (PTRoPGE) will be held June 8-12, 2005 at the University of Texas at Austin. Exciting new and ongoing discoveries show significant regulation of gene expression occurs after transcription. These post-transcriptional control events in plants range from subtle regulation of transcribed genes and phosphorylation, to the processes of gene regulation through small RNAs. This meeting will focus on the regulatory role of RNA, from transcription, through translation and finally degradation. The cross-disciplinary design of this meeting is necessary to encourage interactions between researchers that have a common interest in post-transcriptional genemore » expression in plants. By bringing together a diverse group of plant molecular biologist and biochemists at all careers stages from across the world, this meeting will bring about more rapid progress in understanding how plant genomes work and how genes are finely regulated by post-transcriptional processes to ultimately regulate cells.« less

Fox (forkhead) genes are involved in the dorso-ventral patterning of the Xenopus mesoderm.

PubMed

El-Hodiri, H; Bhatia-Dey, N; Kenyon, K; Ault, K; Dirksen, M; Jamrich, M

2001-01-01

Fox (forkhead/winged helix) genes encode a family of transcription factors that are involved in embryonic pattern formation, regulation of tissue specific gene expression and tumorigenesis. Several of them are transcribed during Xenopus embryogenesis and are important for the patterning of ectoderm, mesoderm and endoderm. We have isolated three forkhead genes that are activated during gastrulation and play an important role in the dorso-ventral patterning of the mesoderm. XFKH1 (FoxA4b), the first vertebrate forkhead gene to be implicated in embryonic pattern formation, is expressed in the Spemann-Mangold organizer region and later in the embryonic notochord. XFKH7, the Xenopus orthologue of the murine Mfh1(Foxc2), is expressed in the presomitic mesoderm, but not in the notochord or lateral plate mesoderm. Finally, XFD-13'(FoxF1b)1 is expressed in the lateral plate mesoderm, but not in the notochord or presomitic mesoderm. Expression pattern and functional experiments indicate that these three forkhead genes are involved in the dorso-ventral patterning of the mesoderm.

Identification of genes showing differential expression profile associated with growth rate in skeletal muscle tissue of Landrace weanling pig.

PubMed

Komatsu, Yuuta; Sukegawa, Shin; Yamashita, Mai; Katsuda, Naoki; Tong, Bin; Ohta, Takeshi; Kose, Hiroyuki; Yamada, Takahisa

2016-06-01

Suppression subtractive hybridization was used to identify genes showing differential expression profile associated with growth rate in skeletal muscle tissue of Landrace weanling pig. Two subtracted cDNA populations were generated from musculus longissimus muscle tissues of selected pigs with extreme expected breeding values at the age of 100 kg. Three upregulated genes (EEF1A2, TSG101 and TTN) and six downregulated genes (ATP5B, ATP5C1, COQ3, HADHA, MYH1 and MYH7) in pig with genetic propensity for higher growth rate were identified by sequence analysis of 12 differentially expressed clones selected by differential screening following the generation of the subtracted cDNA population. Real-time PCR analysis confirmed difference in expression profiles of the identified genes in musculus longissimus muscle tissues between the two Landrace weanling pig groups with divergent genetic propensity for growth rate. Further, differential expression of the identified genes except for the TTN was validated by Western blot analysis. Additionally, the eight genes other than the ATP5C1 colocalized with the same chromosomal positions as QTLs that have been previously identified for growth rate traits. Finally, the changes of expression predicted from gene function suggested association of upregulation of expression of the EEF1A2, TSG101 and TTN genes and downregulation of the ATP5B, ATP5C1, COQ3, HADHA, MYH1 and MYH7 gene expression with increased growth rate. The identified genes will provide an important insight in understanding the molecular mechanism underlying growth rate in Landrace pig breed.

Identifying Epigenetic Biomarkers using Maximal Relevance and Minimal Redundancy Based Feature Selection for Multi-Omics Data.

PubMed

Mallik, Saurav; Bhadra, Tapas; Maulik, Ujjwal

2017-01-01

Epigenetic Biomarker discovery is an important task in bioinformatics. In this article, we develop a new framework of identifying statistically significant epigenetic biomarkers using maximal-relevance and minimal-redundancy criterion based feature (gene) selection for multi-omics dataset. Firstly, we determine the genes that have both expression as well as methylation values, and follow normal distribution. Similarly, we identify the genes which consist of both expression and methylation values, but do not follow normal distribution. For each case, we utilize a gene-selection method that provides maximal-relevant, but variable-weighted minimum-redundant genes as top ranked genes. For statistical validation, we apply t-test on both the expression and methylation data consisting of only the normally distributed top ranked genes to determine how many of them are both differentially expressed andmethylated. Similarly, we utilize Limma package for performing non-parametric Empirical Bayes test on both expression and methylation data comprising only the non-normally distributed top ranked genes to identify how many of them are both differentially expressed and methylated. We finally report the top-ranking significant gene-markerswith biological validation. Moreover, our framework improves positive predictive rate and reduces false positive rate in marker identification. In addition, we provide a comparative analysis of our gene-selection method as well as othermethods based on classificationperformances obtained using several well-known classifiers.

Differences in brain gene expression between sleep and waking as revealed by mRNA differential display and cDNA microarray technology.

PubMed

Cirelli, C; Tononi, G

1999-06-01

The consequences of sleep and sleep deprivation at the molecular level are largely unexplored. Knowledge of such molecular events is essential to understand the restorative processes occurring during sleep as well as the cellular mechanisms of sleep regulation. Here we review the available data about changes in neural gene expression across different behavioural states using candidate gene approaches such as in situ hybridization and immunocytochemistry. We then describe new techniques for systematic screening of gene expression in the brain, such as subtractive hybridization, mRNA differential display, and cDNA microarray technology, outlining advantages and disadvantages of these methods. Finally, we summarize our initial results of a systematic screening of gene expression in the rat brain across behavioural states using mRNA differential display and cDNA microarray technology. The expression pattern of approximately 7000 genes was analysed in the cerebral cortex of rats after 3 h of spontaneous sleep, 3 h of spontaneous waking, or 3 h of sleep deprivation. While the majority of transcripts were expressed at the same level among these three conditions, 14 mRNAs were modulated by sleep and waking. Six transcripts, four more expressed in waking and two more expressed in sleep, corresponded to novel genes. The eight known transcripts were all expressed at higher levels in waking than in sleep and included transcription factors and mitochondrial genes. A possible role for these known transcripts in mediating neural plasticity during waking is discussed.

Embryonic stem cell-like features of testicular carcinoma in situ revealed by genome-wide gene expression profiling.

PubMed

Almstrup, Kristian; Hoei-Hansen, Christina E; Wirkner, Ute; Blake, Jonathon; Schwager, Christian; Ansorge, Wilhelm; Nielsen, John E; Skakkebaek, Niels E; Rajpert-De Meyts, Ewa; Leffers, Henrik

2004-07-15

Carcinoma in situ (CIS) is the common precursor of histologically heterogeneous testicular germ cell tumors (TGCTs), which in recent decades have markedly increased and now are the most common malignancy of young men. Using genome-wide gene expression profiling, we identified >200 genes highly expressed in testicular CIS, including many never reported in testicular neoplasms. Expression was further verified by semiquantitative reverse transcription-PCR and in situ hybridization. Among the highest expressed genes were NANOG and POU5F1, and reverse transcription-PCR revealed possible changes in their stoichiometry on progression into embryonic carcinoma. We compared the CIS expression profile with patterns reported in embryonic stem cells (ESCs), which revealed a substantial overlap that may be as high as 50%. We also demonstrated an over-representation of expressed genes in regions of 17q and 12, reported as unstable in cultured ESCs. The close similarity between CIS and ESCs explains the pluripotency of CIS. Moreover, the findings are consistent with an early prenatal origin of TGCTs and thus suggest that etiologic factors operating in utero are of primary importance for the incidence trends of TGCTs. Finally, some of the highly expressed genes identified in this study are promising candidates for new diagnostic markers for CIS and/or TGCTs.

Gap Gene Regulatory Dynamics Evolve along a Genotype Network

PubMed Central

Crombach, Anton; Wotton, Karl R.; Jiménez-Guri, Eva; Jaeger, Johannes

2016-01-01

Developmental gene networks implement the dynamic regulatory mechanisms that pattern and shape the organism. Over evolutionary time, the wiring of these networks changes, yet the patterning outcome is often preserved, a phenomenon known as “system drift.” System drift is illustrated by the gap gene network—involved in segmental patterning—in dipteran insects. In the classic model organism Drosophila melanogaster and the nonmodel scuttle fly Megaselia abdita, early activation and placement of gap gene expression domains show significant quantitative differences, yet the final patterning output of the system is essentially identical in both species. In this detailed modeling analysis of system drift, we use gene circuits which are fit to quantitative gap gene expression data in M. abdita and compare them with an equivalent set of models from D. melanogaster. The results of this comparative analysis show precisely how compensatory regulatory mechanisms achieve equivalent final patterns in both species. We discuss the larger implications of the work in terms of “genotype networks” and the ways in which the structure of regulatory networks can influence patterns of evolutionary change (evolvability). PMID:26796549

A common haplotype lowers PU.1 expression in myeloid cells and delays onset of Alzheimer's disease.

PubMed

Huang, Kuan-Lin; Marcora, Edoardo; Pimenova, Anna A; Di Narzo, Antonio F; Kapoor, Manav; Jin, Sheng Chih; Harari, Oscar; Bertelsen, Sarah; Fairfax, Benjamin P; Czajkowski, Jake; Chouraki, Vincent; Grenier-Boley, Benjamin; Bellenguez, Céline; Deming, Yuetiva; McKenzie, Andrew; Raj, Towfique; Renton, Alan E; Budde, John; Smith, Albert; Fitzpatrick, Annette; Bis, Joshua C; DeStefano, Anita; Adams, Hieab H H; Ikram, M Arfan; van der Lee, Sven; Del-Aguila, Jorge L; Fernandez, Maria Victoria; Ibañez, Laura; Sims, Rebecca; Escott-Price, Valentina; Mayeux, Richard; Haines, Jonathan L; Farrer, Lindsay A; Pericak-Vance, Margaret A; Lambert, Jean Charles; van Duijn, Cornelia; Launer, Lenore; Seshadri, Sudha; Williams, Julie; Amouyel, Philippe; Schellenberg, Gerard D; Zhang, Bin; Borecki, Ingrid; Kauwe, John S K; Cruchaga, Carlos; Hao, Ke; Goate, Alison M

2017-08-01

A genome-wide survival analysis of 14,406 Alzheimer's disease (AD) cases and 25,849 controls identified eight previously reported AD risk loci and 14 novel loci associated with age at onset. Linkage disequilibrium score regression of 220 cell types implicated the regulation of myeloid gene expression in AD risk. The minor allele of rs1057233 (G), within the previously reported CELF1 AD risk locus, showed association with delayed AD onset and lower expression of SPI1 in monocytes and macrophages. SPI1 encodes PU.1, a transcription factor critical for myeloid cell development and function. AD heritability was enriched within the PU.1 cistrome, implicating a myeloid PU.1 target gene network in AD. Finally, experimentally altered PU.1 levels affected the expression of mouse orthologs of many AD risk genes and the phagocytic activity of mouse microglial cells. Our results suggest that lower SPI1 expression reduces AD risk by regulating myeloid gene expression and cell function.

Oxytocin, vasopressin and estrogen receptor gene expression in relation to social recognition in female mice

PubMed Central

Clipperton-Allen, Amy E.; Lee, Anna W.; Reyes, Anny; Devidze, Nino; Phan, Anna; Pfaff, Donald W.; Choleris, Elena

2012-01-01

Inter- and intra-species differences in social behavior and recognition-related hormones and receptors suggest that different distribution and/or expression patterns may relate to social recognition. We used qRT-PCR to investigate naturally occurring differences in expression of estrogen receptor-alpha (ERα), ER-beta (ERβ), progesterone receptor (PR), oxytocin (OT) and receptor, and vasopressin (AVP) and receptors in proestrous female mice. Following four 5 min exposures to the same two conspecifics, one was replaced with a novel mouse in the final trial (T5). Gene expression was examined in mice showing high (85–100%) and low (40–60%) social recognition scores (i.e., preferential novel mouse investigation in T5) in eight socially-relevant brain regions. Results supported OT and AVP involvement in social recognition, and suggest that in the medial preoptic area, increased OT and AVP mRNA, together with ERα and ERβ gene activation, relate to improved social recognition. Initial social investigation correlated with ERs, PR and OTR in the dorsolateral septum, suggesting that these receptors may modulate social interest without affecting social recognition. Finally, increased lateral amygdala gene activation in the LR mice may be associated with general learning impairments, while decreased lateral amygdala activity may indicate more efficient cognitive mechanisms in the HR mice. PMID:22079582

Non-parent of Origin Expression of Numerous Effector Genes Indicates a Role of Gene Regulation in Host Adaption of the Hybrid Triticale Powdery Mildew Pathogen.

PubMed

Praz, Coraline R; Menardo, Fabrizio; Robinson, Mark D; Müller, Marion C; Wicker, Thomas; Bourras, Salim; Keller, Beat

2018-01-01

Powdery mildew is an important disease of cereals. It is caused by one species, Blumeria graminis , which is divided into formae speciales each of which is highly specialized to one host. Recently, a new form capable of growing on triticale ( B.g. triticale ) has emerged through hybridization between wheat and rye mildews ( B.g. tritici and B.g. secalis , respectively). In this work, we used RNA sequencing to study the molecular basis of host adaptation in B.g. triticale . We analyzed gene expression in three B.g. tritici isolates, two B.g. secalis isolates and two B.g. triticale isolates and identified a core set of putative effector genes that are highly expressed in all formae speciales . We also found that the genes differentially expressed between isolates of the same form as well as between different formae speciales were enriched in putative effectors. Their coding genes belong to several families including some which contain known members of mildew avirulence ( Avr ) and suppressor ( Svr ) genes. Based on these findings we propose that effectors play an important role in host adaptation that is mechanistically based on Avr-Resistance gene-Svr interactions. We also found that gene expression in the B.g. triticale hybrid is mostly conserved with the parent-of-origin, but some genes inherited from B.g. tritici showed a B.g. secalis -like expression. Finally, we identified 11 unambiguous cases of putative effector genes with hybrid-specific, non-parent of origin gene expression, and we propose that they are possible determinants of host specialization in triticale mildew. These data suggest that altered expression of multiple effector genes, in particular Avr and Svr related factors, might play a role in mildew host adaptation based on hybridization.

Development of a Synthetic Oxytetracycline-Inducible Expression System for Streptomycetes Using de Novo Characterized Genetic Parts.

PubMed

Wang, Weishan; Yang, Tongjian; Li, Yihong; Li, Shanshan; Yin, Shouliang; Styles, Kathryn; Corre, Christophe; Yang, Keqian

2016-07-15

Precise control of gene expression using exogenous factors is of great significance. To develop ideal inducible expression systems for streptomycetes, new genetic parts, oxytetracycline responsive repressor OtrR, operator otrO, and promoter otrBp from Streptomyces rimosus, were selected de novo and characterized in vivo and in vitro. OtrR showed strong affinity to otrO (KD = 1.7 × 10(-10) M) and oxytetracycline induced dissociation of the OtrR/DNA complex in a concentration-dependent manner. On the basis of these genetic parts, a synthetic inducible expression system Potr* was optimized. Induction of Potr* with 0.01-4 μM of oxytetracycline triggered a wide-range expression level of gfp reporter gene in different Streptomyces species. Benchmarking Potr* against the widely used constitutive promoters ermE* and kasOp* revealed greatly enhanced levels of expression when Potr* was fully induced. Finally, Potr* was used as a tool to activate and optimize the expression of the silent jadomycin biosynthetic gene cluster in Streptomyces venezuelae. Altogether, the synthetic Potr* presents a new versatile tool for fine-tuning gene expression in streptomycetes.

Gene Expression Profiling of Peripheral Blood From Kidney Transplant Recipients for the Early Detection of Digestive System Cancer.

PubMed

Kusaka, M; Okamoto, M; Takenaka, M; Sasaki, H; Fukami, N; Kataoka, K; Ito, T; Kenmochi, T; Hoshinaga, K; Shiroki, R

2017-06-01

Kidney transplant recipients are at increased risk of developing cancer in comparison with the general population. To effectively manage post-transplantation malignancies, it is essential to proactively monitor patients. A long-term intensive screening program was associated with a reduced incidence of cancer after transplantation. This study evaluated the usefulness of the gene expression profiling of peripheral blood samples obtained from kidney transplant patients and adopted a screening test for detecting cancer of the digestive system (gastric, colon, pancreas, and biliary tract). Nineteen patients were included in this study and a total of 53 gene expression screening tests were performed. The gene expression profiles of blood-delivered total RNA and whole genome human gene expression profiles were obtained. We investigated the expression levels of 2665 genes associated with digestive cancers and counted the number of genes in which expression was altered. A hierarchical clustering analysis was also performed. The final prediction of the cancer possibility was determined according to an algorithm. The number of genes in which expression was altered was significantly increased in the kidney transplant recipients in comparison with the general population (1091 ± 63 vs 823 ± 94; P = .0024). The number of genes with altered expression decreased after the induction of mechanistic target of rapamycin (mTOR) inhibitor (1484 ± 227 vs 883 ± 154; P = .0439). No cases of possible digestive cancer were detected in this study period. The gene expression profiling of peripheral blood samples may be a useful and noninvasive diagnostic tool that allows for the early detection of cancer of the digestive system. Copyright © 2017 Elsevier Inc. All rights reserved.

The human TREM gene cluster at 6p21.1 encodes both activating and inhibitory single IgV domain receptors and includes NKp44.

PubMed

Allcock, Richard J N; Barrow, Alexander D; Forbes, Simon; Beck, Stephan; Trowsdale, John

2003-02-01

We have characterized a cluster of single immunoglobulin variable (IgV) domain receptors centromeric of the major histocompatibility complex (MHC) on human chromosome 6. In addition to triggering receptor expressed on myeloid cells (TREM)-1 and TREM2, the cluster contains NKp44, a triggering receptor whose expression is limited to NK cells. We identified three new related genes and two gene fragments within a cluster of approximately 200 kb. Two of the three new genes lack charged residues in their transmembrane domain tails. Further, one of the genes contains two potential immunotyrosine Inhibitory motifs in its cytoplasmic tail, suggesting that it delivers inhibitory signals. The human and mouse TREM clusters appear to have diverged such that there are unique sequences in each species. Finally, each gene in the TREM cluster was expressed in a different range of cell types.

RAS oncogene-mediated deregulation of the transcriptome: from molecular signature to function.

PubMed

Schäfer, Reinhold; Sers, Christine

2011-01-01

Transcriptome analysis of cancer cells has developed into a standard procedure to elucidate multiple features of the malignant process and to link gene expression to clinical properties. Gene expression profiling based on microarrays provides essentially correlative information and needs to be transferred to the functional level in order to understand the activity and contribution of individual genes or sets of genes as elements of the gene signature. To date, there exist significant gaps in the functional understanding of gene expression profiles. Moreover, the processes that drive the profound transcriptional alterations that characterize cancer cells remain mainly elusive. We have used pathway-restricted gene expression profiles derived from RAS oncogene-transformed cells and from RAS-expressing cancer cells to identify regulators downstream of the MAPK pathway.We describe the role of epigenetic regulation exemplified by the control of several immune genes in generic cell lines and colorectal cancer cells, particularly the functional interaction between signaling and DNA methylation. Moreover, we assess the role of the architectural transcription factor high mobility AT-hook 2 (HMGA2) as a regulator of the RAS-responsive transcriptome in ovarian epithelial cells. Finally, we describe an integrated approach combining pathway interference in colorectal cancer cells, gene expression profiling and computational analysis of regulatory elements of deregulated target genes. This strategy resulted in the identification of Y-box binding protein 1 (YBX1) as a regulator of MAPK-dependent proliferation and gene expression. The implications for a therapeutic application of HMGA2 gene silencing and the role of YBX1 as a prognostic factor are discussed.

Ossification of the posterior longitudinal ligament related genes identification using microarray gene expression profiling and bioinformatics analysis.

PubMed

He, Hailong; Mao, Lingzhou; Xu, Peng; Xi, Yanhai; Xu, Ning; Xue, Mingtao; Yu, Jiangming; Ye, Xiaojian

2014-01-10

Ossification of the posterior longitudinal ligament (OPLL) is a kind of disease with physical barriers and neurological disorders. The objective of this study was to explore the differentially expressed genes (DEGs) in OPLL patient ligament cells and identify the target sites for the prevention and treatment of OPLL in clinic. Gene expression data GSE5464 was downloaded from Gene Expression Omnibus; then DEGs were screened by limma package in R language, and changed functions and pathways of OPLL cells compared to normal cells were identified by DAVID (The Database for Annotation, Visualization and Integrated Discovery); finally, an interaction network of DEGs was constructed by string. A total of 1536 DEGs were screened, with 31 down-regulated and 1505 up-regulated genes. Response to wounding function and Toll-like receptor signaling pathway may involve in the development of OPLL. Genes, such as PDGFB, PRDX2 may involve in OPLL through response to wounding function. Toll-like receptor signaling pathway enriched genes such as TLR1, TLR5, and TLR7 may involve in spine cord injury in OPLL. PIK3R1 was the hub gene in the network of DEGs with the highest degree; INSR was one of the most closely related genes of it. OPLL related genes screened by microarray gene expression profiling and bioinformatics analysis may be helpful for elucidating the mechanism of OPLL. © 2013.

Porcine transcriptome analysis based on 97 non-normalized cDNA libraries and assembly of 1,021,891 expressed sequence tags

PubMed Central

Gorodkin, Jan; Cirera, Susanna; Hedegaard, Jakob; Gilchrist, Michael J; Panitz, Frank; Jørgensen, Claus; Scheibye-Knudsen, Karsten; Arvin, Troels; Lumholdt, Steen; Sawera, Milena; Green, Trine; Nielsen, Bente J; Havgaard, Jakob H; Rosenkilde, Carina; Wang, Jun; Li, Heng; Li, Ruiqiang; Liu, Bin; Hu, Songnian; Dong, Wei; Li, Wei; Yu, Jun; Wang, Jian; Stærfeldt, Hans-Henrik; Wernersson, Rasmus; Madsen, Lone B; Thomsen, Bo; Hornshøj, Henrik; Bujie, Zhan; Wang, Xuegang; Wang, Xuefei; Bolund, Lars; Brunak, Søren; Yang, Huanming; Bendixen, Christian; Fredholm, Merete

2007-01-01

Background Knowledge of the structure of gene expression is essential for mammalian transcriptomics research. We analyzed a collection of more than one million porcine expressed sequence tags (ESTs), of which two-thirds were generated in the Sino-Danish Pig Genome Project and one-third are from public databases. The Sino-Danish ESTs were generated from one normalized and 97 non-normalized cDNA libraries representing 35 different tissues and three developmental stages. Results Using the Distiller package, the ESTs were assembled to roughly 48,000 contigs and 73,000 singletons, of which approximately 25% have a high confidence match to UniProt. Approximately 6,000 new porcine gene clusters were identified. Expression analysis based on the non-normalized libraries resulted in the following findings. The distribution of cluster sizes is scaling invariant. Brain and testes are among the tissues with the greatest number of different expressed genes, whereas tissues with more specialized function, such as developing liver, have fewer expressed genes. There are at least 65 high confidence housekeeping gene candidates and 876 cDNA library-specific gene candidates. We identified differential expression of genes between different tissues, in particular brain/spinal cord, and found patterns of correlation between genes that share expression in pairs of libraries. Finally, there was remarkable agreement in expression between specialized tissues according to Gene Ontology categories. Conclusion This EST collection, the largest to date in pig, represents an essential resource for annotation, comparative genomics, assembly of the pig genome sequence, and further porcine transcription studies. PMID:17407547

Identification and validation of superior reference gene for gene expression normalization via RT-qPCR in staminate and pistillate flowers of Jatropha curcas - A biodiesel plant.

PubMed

Karuppaiya, Palaniyandi; Yan, Xiao-Xue; Liao, Wang; Wu, Jun; Chen, Fang; Tang, Lin

2017-01-01

Physic nut (Jatropha curcas L) seed oil is a natural resource for the alternative production of fossil fuel. Seed oil production is mainly depended on seed yield, which was restricted by the low ratio of staminate flowers to pistillate flowers. Further, the mechanism of physic nut flower sex differentiation has not been fully understood yet. Quantitative Real Time-Polymerase Chain Reaction is a reliable and widely used technique to quantify the gene expression pattern in biological samples. However, for accuracy of qRT-PCR, appropriate reference gene is highly desirable to quantify the target gene level. Hence, the present study was aimed to identify the stable reference genes in staminate and pistillate flowers of J. curcas. In this study, 10 candidate reference genes were selected and evaluated for their expression stability in staminate and pistillate flowers, and their stability was validated by five different algorithms (ΔCt, BestKeeper, NormFinder, GeNorm and RefFinder). Resulting, TUB and EF found to be the two most stably expressed reference for staminate flower; while GAPDH1 and EF found to be the most stably expressed reference gene for pistillate flowers. Finally, RT-qPCR assays of target gene AGAMOUS using the identified most stable reference genes confirmed the reliability of selected reference genes in different stages of flower development. AGAMOUS gene expression levels at different stages were further proved by gene copy number analysis. Therefore, the present study provides guidance for selecting appropriate reference genes for analyzing the expression pattern of floral developmental genes in staminate and pistillate flowers of J. curcas.

Identification and validation of superior reference gene for gene expression normalization via RT-qPCR in staminate and pistillate flowers of Jatropha curcas – A biodiesel plant

PubMed Central

Karuppaiya, Palaniyandi; Yan, Xiao-Xue; Liao, Wang; Chen, Fang; Tang, Lin

2017-01-01

Physic nut (Jatropha curcas L) seed oil is a natural resource for the alternative production of fossil fuel. Seed oil production is mainly depended on seed yield, which was restricted by the low ratio of staminate flowers to pistillate flowers. Further, the mechanism of physic nut flower sex differentiation has not been fully understood yet. Quantitative Real Time—Polymerase Chain Reaction is a reliable and widely used technique to quantify the gene expression pattern in biological samples. However, for accuracy of qRT-PCR, appropriate reference gene is highly desirable to quantify the target gene level. Hence, the present study was aimed to identify the stable reference genes in staminate and pistillate flowers of J. curcas. In this study, 10 candidate reference genes were selected and evaluated for their expression stability in staminate and pistillate flowers, and their stability was validated by five different algorithms (ΔCt, BestKeeper, NormFinder, GeNorm and RefFinder). Resulting, TUB and EF found to be the two most stably expressed reference for staminate flower; while GAPDH1 and EF found to be the most stably expressed reference gene for pistillate flowers. Finally, RT-qPCR assays of target gene AGAMOUS using the identified most stable reference genes confirmed the reliability of selected reference genes in different stages of flower development. AGAMOUS gene expression levels at different stages were further proved by gene copy number analysis. Therefore, the present study provides guidance for selecting appropriate reference genes for analyzing the expression pattern of floral developmental genes in staminate and pistillate flowers of J. curcas. PMID:28234941

Transcriptome sequencing reveals high isoform diversity in the ant Formica exsecta

PubMed Central

Paviala, Jenni; Morandin, Claire; Wheat, Christopher; Sundström, Liselotte; Helanterä, Heikki

2017-01-01

Transcriptome resources for social insects have the potential to provide new insight into polyphenism, i.e., how divergent phenotypes arise from the same genome. Here we present a transcriptome based on paired-end RNA sequencing data for the ant Formica exsecta (Formicidae, Hymenoptera). The RNA sequencing libraries were constructed from samples of several life stages of both sexes and female castes of queens and workers, in order to maximize representation of expressed genes. We first compare the performance of common assembly and scaffolding software (Trinity, Velvet-Oases, and SOAPdenovo-trans), in producing de novo assemblies. Second, we annotate the resulting expressed contigs to the currently published genomes of ants, and other insects, including the honeybee, to filter genes that have annotation evidence of being true genes. Our pipeline resulted in a final assembly of altogether 39,262 mRNA transcripts, with an average coverage of >300X, belonging to 17,496 unique genes with annotation in the related ant species. From these genes, 536 genes were unique to one caste or sex only, highlighting the importance of comprehensive sampling. Our final assembly also showed expression of several splice variants in 6,975 genes, and we show that accounting for splice variants affects the outcome of downstream analyses such as gene ontologies. Our transcriptome provides an outstanding resource for future genetic studies on F. exsecta and other ant species, and the presented transcriptome assembly can be adapted to any non-model species that has genomic resources available from a related taxon. PMID:29177112

A method to identify differential expression profiles of time-course gene data with Fourier transformation.

PubMed

Kim, Jaehee; Ogden, Robert Todd; Kim, Haseong

2013-10-18

Time course gene expression experiments are an increasingly popular method for exploring biological processes. Temporal gene expression profiles provide an important characterization of gene function, as biological systems are both developmental and dynamic. With such data it is possible to study gene expression changes over time and thereby to detect differential genes. Much of the early work on analyzing time series expression data relied on methods developed originally for static data and thus there is a need for improved methodology. Since time series expression is a temporal process, its unique features such as autocorrelation between successive points should be incorporated into the analysis. This work aims to identify genes that show different gene expression profiles across time. We propose a statistical procedure to discover gene groups with similar profiles using a nonparametric representation that accounts for the autocorrelation in the data. In particular, we first represent each profile in terms of a Fourier basis, and then we screen out genes that are not differentially expressed based on the Fourier coefficients. Finally, we cluster the remaining gene profiles using a model-based approach in the Fourier domain. We evaluate the screening results in terms of sensitivity, specificity, FDR and FNR, compare with the Gaussian process regression screening in a simulation study and illustrate the results by application to yeast cell-cycle microarray expression data with alpha-factor synchronization.The key elements of the proposed methodology: (i) representation of gene profiles in the Fourier domain; (ii) automatic screening of genes based on the Fourier coefficients and taking into account autocorrelation in the data, while controlling the false discovery rate (FDR); (iii) model-based clustering of the remaining gene profiles. Using this method, we identified a set of cell-cycle-regulated time-course yeast genes. The proposed method is general and can be potentially used to identify genes which have the same patterns or biological processes, and help facing the present and forthcoming challenges of data analysis in functional genomics.

Divergence of Gene Body DNA Methylation and Evolution of Plant Duplicate Genes

PubMed Central

Wang, Jun; Marowsky, Nicholas C.; Fan, Chuanzhu

2014-01-01

It has been shown that gene body DNA methylation is associated with gene expression. However, whether and how deviation of gene body DNA methylation between duplicate genes can influence their divergence remains largely unexplored. Here, we aim to elucidate the potential role of gene body DNA methylation in the fate of duplicate genes. We identified paralogous gene pairs from Arabidopsis and rice (Oryza sativa ssp. japonica) genomes and reprocessed their single-base resolution methylome data. We show that methylation in paralogous genes nonlinearly correlates with several gene properties including exon number/gene length, expression level and mutation rate. Further, we demonstrated that divergence of methylation level and pattern in paralogs indeed positively correlate with their sequence and expression divergences. This result held even after controlling for other confounding factors known to influence the divergence of paralogs. We observed that methylation level divergence might be more relevant to the expression divergence of paralogs than methylation pattern divergence. Finally, we explored the mechanisms that might give rise to the divergence of gene body methylation in paralogs. We found that exonic methylation divergence more closely correlates with expression divergence than intronic methylation divergence. We show that genomic environments (e.g., flanked by transposable elements and repetitive sequences) of paralogs generated by various duplication mechanisms are associated with the methylation divergence of paralogs. Overall, our results suggest that the changes in gene body DNA methylation could provide another avenue for duplicate genes to develop differential expression patterns and undergo different evolutionary fates in plant genomes. PMID:25310342

Transcriptional response of Pasteurella multocida to defined iron sources.

PubMed

Paustian, Michael L; May, Barbara J; Cao, Dongwei; Boley, Daniel; Kapur, Vivek

2002-12-01

Pasteurella multocida was grown in iron-free chemically defined medium supplemented with hemoglobin, transferrin, ferritin, and ferric citrate as iron sources. Whole-genome DNA microarrays were used to monitor global gene expression over seven time points after the addition of the defined iron source to the medium. This resulted in a set of data containing over 338,000 gene expression observations. On average, 12% of P. multocida genes were differentially expressed under any single condition. A majority of these genes encoded P. multocida proteins that were involved in either transport and binding or were annotated as hypothetical proteins. Several trends are evident when the data from different iron sources are compared. In general, only two genes (ptsN and sapD) were expressed at elevated levels under all of the conditions tested. The results also show that genes with increased expression in the presence of hemoglobin did not respond to transferrin or ferritin as an iron source. Correspondingly, genes with increased expression in the transferrin and ferritin experiments were expressed at reduced levels when hemoglobin was supplied as the sole iron source. Finally, the data show that genes that were most responsive to the presence of ferric citrate did not follow a trend similar to that of the other iron sources, suggesting that different pathways respond to inorganic or organic sources of iron in P. multocida. Taken together, our results demonstrate that unique subsets of P. multocida genes are expressed in response to different iron sources and that many of these genes have yet to be functionally characterized.

Identification of differentially expressed genes related to aphid resistance in cucumber (Cucumis sativus L.)

PubMed Central

Liang, Danna; Liu, Min; Hu, Qijing; He, Min; Qi, Xiaohua; Xu, Qiang; Zhou, Fucai; Chen, Xuehao

2015-01-01

Cucumber, a very important vegetable crop worldwide, is easily damaged by pests. Aphids (Aphis gossypii Glover) are among the most serious pests in cucumber production and often cause severe loss of yield and make fruit quality get worse. Identifying genes that render cucumbers resistant to aphid-induced damage and breeding aphid-resistant cucumber varieties have become the most promising control strategies. In this study, a Illumina Genome Analyzer platform was applied to monitor changes in gene expression in the whole genome of the cucumber cultivar ‘EP6392’ which is resistant to aphids. Nine DGE libraries were constructed from infected and uninfected leaves. In total, 49 differentially expressed genes related to cucumber aphid resistance were screened during the treatment period. These genes are mainly associated with signal transduction, plant-pathogen interactions, flavonoid biosynthesis, amino acid metabolism and sugar metabolism pathways. Eight of the 49 genes may be associated with aphid resistance. Finally, expression of 9 randomly selected genes was evaluated by qRT-PCR to verify the results for the tag-mapped genes. With the exception of 1-aminocyclopropane-1-carboxylate oxidase homolog 6, the expression of the chosen genes was in agreement with the results of the tag-sequencing analysis patterns. PMID:25959296

Protein-protein interaction network of gene expression in the hydrocortisone-treated keloid.

PubMed

Chen, Rui; Zhang, Zhiliang; Xue, Zhujia; Wang, Lin; Fu, Mingang; Lu, Yi; Bai, Ling; Zhang, Ping; Fan, Zhihong

2015-01-01

In order to explore the molecular mechanism of hydrocortisone in keloid tissue, the gene expression profiles of keloid samples treated with hydrocortisone were subjected to bioinformatics analysis. Firstly, the gene expression profiles (GSE7890) of five samples of keloid treated with hydrocortisone and five untreated keloid samples were downloaded from the Gene Expression Omnibus (GEO) database. Secondly, data were preprocessed using packages in R language and differentially expressed genes (DEGs) were screened using a significance analysis of microarrays (SAM) protocol. Thirdly, the DEGs were subjected to gene ontology (GO) function and KEGG pathway enrichment analysis. Finally, the interactions of DEGs in samples of keloid treated with hydrocortisone were explored in a human protein-protein interaction (PPI) network, and sub-modules of the DEGs interaction network were analyzed using Cytoscape software. Based on the analysis, 572 DEGs in the hydrocortisone-treated samples were screened; most of these were involved in the signal transduction and cell cycle. Furthermore, three critical genes in the module, including COL1A1, NID1, and PRELP, were screened in the PPI network analysis. These findings enhance understanding of the pathogenesis of the keloid and provide references for keloid therapy. © 2015 The International Society of Dermatology.

Regulators of gene expression as biomarkers for prostate cancer

PubMed Central

Willard, Stacey S; Koochekpour, Shahriar

2012-01-01

Recent technological advancements in gene expression analysis have led to the discovery of a promising new group of prostate cancer (PCa) biomarkers that have the potential to influence diagnosis and the prediction of disease severity. The accumulation of deleterious changes in gene expression is a fundamental mechanism of prostate carcinogenesis. Aberrant gene expression can arise from changes in epigenetic regulation or mutation in the genome affecting either key regulatory elements or gene sequences themselves. At the epigenetic level, a myriad of abnormal histone modifications and changes in DNA methylation are found in PCa patients. In addition, many mutations in the genome have been associated with higher PCa risk. Finally, over- or underexpression of key genes involved in cell cycle regulation, apoptosis, cell adhesion and regulation of transcription has been observed. An interesting group of biomarkers are emerging from these studies which may prove more predictive than the standard prostate specific antigen (PSA) serum test. In this review, we discuss recent results in the field of gene expression analysis in PCa including the most promising biomarkers in the areas of epigenetics, genomics and the transcriptome, some of which are currently under investigation as clinical tests for early detection and better prognostic prediction of PCa. PMID:23226612

DNA Microarray Highlights Nrf2-Mediated Neuron Protection Targeted by Wasabi-Derived Isothiocyanates in IMR-32 Cells

PubMed Central

Trio, Phoebe Zapanta; Fujisaki, Satoru; Tanigawa, Shunsuke; Hisanaga, Ayami; Sakao, Kozue; Hou, De-Xing

2016-01-01

6-(Methylsulfinyl)hexyl isothiocyanate (6-MSITC), 6-(methylthio)hexyl isothiocyanate (6-MTITC), and 4-(methylsulfinyl)butyl isothiocyanate (4-MSITC) are isothiocyanate (ITC) bioactive compounds from Japanese Wasabi. Previous in vivo studies highlighted the neuroprotective potential of ITCs since ITCs enhance the production of antioxidant-related enzymes. Thus, in this present study, a genome-wide DNA microarray analysis was designed to profile gene expression changes in a neuron cell line, IMR-32, stimulated by these ITCs. Among these ITCs, 6-MSITC caused the expression changes of most genes (263), of which 100 genes were upregulated and 163 genes were downregulated. Gene categorization showed that most of the differentially expressed genes are involved in oxidative stress response, and pathway analysis further revealed that Nrf2-mediated oxidative stress pathway is the top of the ITC-modulated signaling pathway. Finally, real-time polymerase chain reaction (PCR) and Western blotting confirmed the gene expression and protein products of the major targets by ITCs. Taken together, Wasabi-derived ITCs might target the Nrf2-mediated oxidative stress pathway to exert neuroprotective effects. PMID:27547033

DNA Microarray Highlights Nrf2-Mediated Neuron Protection Targeted by Wasabi-Derived Isothiocyanates in IMR-32 Cells.

PubMed

Trio, Phoebe Zapanta; Fujisaki, Satoru; Tanigawa, Shunsuke; Hisanaga, Ayami; Sakao, Kozue; Hou, De-Xing

2016-01-01

6-(Methylsulfinyl)hexyl isothiocyanate (6-MSITC), 6-(methylthio)hexyl isothiocyanate (6-MTITC), and 4-(methylsulfinyl)butyl isothiocyanate (4-MSITC) are isothiocyanate (ITC) bioactive compounds from Japanese Wasabi. Previous in vivo studies highlighted the neuroprotective potential of ITCs since ITCs enhance the production of antioxidant-related enzymes. Thus, in this present study, a genome-wide DNA microarray analysis was designed to profile gene expression changes in a neuron cell line, IMR-32, stimulated by these ITCs. Among these ITCs, 6-MSITC caused the expression changes of most genes (263), of which 100 genes were upregulated and 163 genes were downregulated. Gene categorization showed that most of the differentially expressed genes are involved in oxidative stress response, and pathway analysis further revealed that Nrf2-mediated oxidative stress pathway is the top of the ITC-modulated signaling pathway. Finally, real-time polymerase chain reaction (PCR) and Western blotting confirmed the gene expression and protein products of the major targets by ITCs. Taken together, Wasabi-derived ITCs might target the Nrf2-mediated oxidative stress pathway to exert neuroprotective effects.

Network-Induced Classification Kernels for Gene Expression Profile Analysis

PubMed Central

Dror, Gideon; Shamir, Ron

2012-01-01

Abstract Computational classification of gene expression profiles into distinct disease phenotypes has been highly successful to date. Still, robustness, accuracy, and biological interpretation of the results have been limited, and it was suggested that use of protein interaction information jointly with the expression profiles can improve the results. Here, we study three aspects of this problem. First, we show that interactions are indeed relevant by showing that co-expressed genes tend to be closer in the network of interactions. Second, we show that the improved performance of one extant method utilizing expression and interactions is not really due to the biological information in the network, while in another method this is not the case. Finally, we develop a new kernel method—called NICK—that integrates network and expression data for SVM classification, and demonstrate that overall it achieves better results than extant methods while running two orders of magnitude faster. PMID:22697242

Evaluation and Validation of Reference Genes for qRT-PCR Normalization in Frankliniella occidentalis (Thysanoptera:Thripidae)

PubMed Central

Zheng, Yu-Tao; Li, Hong-Bo; Lu, Ming-Xing; Du, Yu-Zhou

2014-01-01

Quantitative real time PCR (qRT-PCR) has emerged as a reliable and reproducible technique for studying gene expression analysis. For accurate results, the normalization of data with reference genes is particularly essential. Once the transcriptome sequencing of Frankliniella occidentalis was completed, numerous unigenes were identified and annotated. Unfortunately, there are no studies on the stability of reference genes used in F. occidentalis. In this work, seven candidate reference genes, including actin, 18S rRNA, H3, tubulin, GAPDH, EF-1 and RPL32, were evaluated for their suitability as normalization genes under different experimental conditions using the statistical software programs BestKeeper, geNorm, Normfinder and the comparative ΔCt method. Because the rankings of the reference genes provided by each of the four programs were different, we chose a user-friendly web-based comprehensive tool RefFinder to get the final ranking. The result demonstrated that EF-1 and RPL32 displayed the most stable expression in different developmental stages; RPL32 and GAPDH showed the most stable expression at high temperatures, while 18S and EF-1 exhibited the most stable expression at low temperatures. In this study, we validated the suitable reference genes in F. occidentalis for gene expression profiling under different experimental conditions. The choice of internal standard is very important in the normalization of the target gene expression levels, thus validating and selecting the best genes will help improve the quality of gene expression data of F. occidentalis. What is more, these validated reference genes could serve as the basis for the selection of candidate reference genes in other insects. PMID:25356721

Evaluation and validation of reference genes for qRT-PCR normalization in Frankliniella occidentalis (Thysanoptera: Thripidae).

PubMed

Zheng, Yu-Tao; Li, Hong-Bo; Lu, Ming-Xing; Du, Yu-Zhou

2014-01-01

Quantitative real time PCR (qRT-PCR) has emerged as a reliable and reproducible technique for studying gene expression analysis. For accurate results, the normalization of data with reference genes is particularly essential. Once the transcriptome sequencing of Frankliniella occidentalis was completed, numerous unigenes were identified and annotated. Unfortunately, there are no studies on the stability of reference genes used in F. occidentalis. In this work, seven candidate reference genes, including actin, 18S rRNA, H3, tubulin, GAPDH, EF-1 and RPL32, were evaluated for their suitability as normalization genes under different experimental conditions using the statistical software programs BestKeeper, geNorm, Normfinder and the comparative ΔCt method. Because the rankings of the reference genes provided by each of the four programs were different, we chose a user-friendly web-based comprehensive tool RefFinder to get the final ranking. The result demonstrated that EF-1 and RPL32 displayed the most stable expression in different developmental stages; RPL32 and GAPDH showed the most stable expression at high temperatures, while 18S and EF-1 exhibited the most stable expression at low temperatures. In this study, we validated the suitable reference genes in F. occidentalis for gene expression profiling under different experimental conditions. The choice of internal standard is very important in the normalization of the target gene expression levels, thus validating and selecting the best genes will help improve the quality of gene expression data of F. occidentalis. What is more, these validated reference genes could serve as the basis for the selection of candidate reference genes in other insects.

How powerful are summary-based methods for identifying expression-trait associations under different genetic architectures?

PubMed

Veturi, Yogasudha; Ritchie, Marylyn D

2018-01-01

Transcriptome-wide association studies (TWAS) have recently been employed as an approach that can draw upon the advantages of genome-wide association studies (GWAS) and gene expression studies to identify genes associated with complex traits. Unlike standard GWAS, summary level data suffices for TWAS and offers improved statistical power. Two popular TWAS methods include either (a) imputing the cis genetic component of gene expression from smaller sized studies (using multi-SNP prediction or MP) into much larger effective sample sizes afforded by GWAS - TWAS-MP or (b) using summary-based Mendelian randomization - TWAS-SMR. Although these methods have been effective at detecting functional variants, it remains unclear how extensive variability in the genetic architecture of complex traits and diseases impacts TWAS results. Our goal was to investigate the different scenarios under which these methods yielded enough power to detect significant expression-trait associations. In this study, we conducted extensive simulations based on 6000 randomly chosen, unrelated Caucasian males from Geisinger's MyCode population to compare the power to detect cis expression-trait associations (within 500 kb of a gene) using the above-described approaches. To test TWAS across varying genetic backgrounds we simulated gene expression and phenotype using different quantitative trait loci per gene and cis-expression /trait heritability under genetic models that differentiate the effect of causality from that of pleiotropy. For each gene, on a training set ranging from 100 to 1000 individuals, we either (a) estimated regression coefficients with gene expression as the response using five different methods: LASSO, elastic net, Bayesian LASSO, Bayesian spike-slab, and Bayesian ridge regression or (b) performed eQTL analysis. We then sampled with replacement 50,000, 150,000, and 300,000 individuals respectively from the testing set of the remaining 5000 individuals and conducted GWAS on each set. Subsequently, we integrated the GWAS summary statistics derived from the testing set with the weights (or eQTLs) derived from the training set to identify expression-trait associations using (a) TWAS-MP (b) TWAS-SMR (c) eQTL-based GWAS, or (d) standalone GWAS. Finally, we examined the power to detect functionally relevant genes using the different approaches under the considered simulation scenarios. In general, we observed great similarities among TWAS-MP methods although the Bayesian methods resulted in improved power in comparison to LASSO and elastic net as the trait architecture grew more complex while training sample sizes and expression heritability remained small. Finally, we observed high power under causality but very low to moderate power under pleiotropy.

Differential gene expression in patients with subsyndromal symptomatic depression and major depressive disorder.

PubMed

Yang, Chengqing; Hu, Guoqin; Li, Zezhi; Wang, Qingzhong; Wang, Xuemei; Yuan, Chengmei; Wang, Zuowei; Hong, Wu; Lu, Weihong; Cao, Lan; Chen, Jun; Wang, Yong; Yu, Shunying; Zhou, Yimin; Yi, Zhenghui; Fang, Yiru

2017-01-01

Subsyndromal symptomatic depression (SSD) is a subtype of subthreshold depressive and can lead to significant psychosocial functional impairment. Although the pathogenesis of major depressive disorder (MDD) and SSD still remains poorly understood, a set of studies have found that many same genetic factors play important roles in the etiology of these two disorders. Nowadays, the differential gene expression between MDD and SSD is still unknown. In our previous study, we compared the expression profile and made the classification with the leukocytes by using whole-genome cRNA microarrays among drug-free first-episode subjects with SSD, MDD and matched healthy controls (8 subjects in each group), and finally determined 48 gene expression signatures. Based on these findings, we further clarify whether these genes mRNA was different expressed in peripheral blood in patients with SSD, MDD and healthy controls (60 subjects respectively). With the help of the quantitative real-time reverse transcription-polymerase chain reaction (RT-qPCR), we gained gene relative expression levels among the three groups. We found that there are three of the forty eight co-regulated genes had differential expression in peripheral blood among the three groups, which are CD84, STRN, CTNS gene (F = 3.528, p = 0.034; F = 3.382, p = 0.039; F = 3.801, p = 0.026, respectively) while there were no significant differences for other genes. CD84, STRN, CTNS gene may have significant value for performing diagnostic functions and classifying SSD, MDD and healthy controls.

Aging Shapes the Population-Mean and -Dispersion of Gene Expression in Human Brains

PubMed Central

Brinkmeyer-Langford, Candice L.; Guan, Jinting; Ji, Guoli; Cai, James J.

2016-01-01

Human aging is associated with cognitive decline and an increased risk of neurodegenerative disease. Our objective for this study was to evaluate potential relationships between age and variation in gene expression across different regions of the brain. We analyzed the Genotype-Tissue Expression (GTEx) data from 54 to 101 tissue samples across 13 brain regions in post-mortem donors of European descent aged between 20 and 70 years at death. After accounting for the effects of covariates and hidden confounding factors, we identified 1446 protein-coding genes whose expression in one or more brain regions is correlated with chronological age at a false discovery rate of 5%. These genes are involved in various biological processes including apoptosis, mRNA splicing, amino acid biosynthesis, and neurotransmitter transport. The distribution of these genes among brain regions is uneven, suggesting variable regional responses to aging. We also found that the aging response of many genes, e.g., TP37 and C1QA, depends on individuals' genotypic backgrounds. Finally, using dispersion-specific analysis, we identified genes such as IL7R, MS4A4E, and TERF1/TERF2 whose expressions are differentially dispersed by aging, i.e., variances differ between age groups. Our results demonstrate that age-related gene expression is brain region-specific, genotype-dependent, and associated with both mean and dispersion changes. Our findings provide a foundation for more sophisticated gene expression modeling in the studies of age-related neurodegenerative diseases. PMID:27536236

A novel gene expression-based prognostic scoring system to predict survival in gastric cancer

DOE PAGES

Wang, Pin; Wang, Yunshan; Hang, Bo; ...

2016-07-11

Analysis of gene expression patterns in gastric cancer (GC) can help to identify a comprehensive panel of gene biomarkers for predicting clinical outcomes and to discover potential new therapeutic targets. Here, a multi-step bioinformatics analytic approach was developed to establish a novel prognostic scoring system for GC. We first identified 276 genes that were robustly differentially expressed between normal and GC tissues, of which, 249 were found to be significantly associated with overall survival (OS) by univariate Cox regression analysis. The biological functions of 249 genes are related to cell cycle, RNA/ncRNA process, acetylation and extracellular matrix organization. A networkmore » was generated for view of the gene expression architecture of 249 genes in 265 GCs. Finally, we applied a canonical discriminant analysis approach to identify a 53-gene signature and a prognostic scoring system was established based on a canonical discriminant function of 53 genes. The prognostic scores strongly predicted patients with GC to have either a poor or good OS. Our study raises the prospect that the practicality of GC patient prognosis can be assessed by this prognostic scoring system.« less

A novel gene expression-based prognostic scoring system to predict survival in gastric cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Pin; Wang, Yunshan; Hang, Bo

Analysis of gene expression patterns in gastric cancer (GC) can help to identify a comprehensive panel of gene biomarkers for predicting clinical outcomes and to discover potential new therapeutic targets. Here, a multi-step bioinformatics analytic approach was developed to establish a novel prognostic scoring system for GC. We first identified 276 genes that were robustly differentially expressed between normal and GC tissues, of which, 249 were found to be significantly associated with overall survival (OS) by univariate Cox regression analysis. The biological functions of 249 genes are related to cell cycle, RNA/ncRNA process, acetylation and extracellular matrix organization. A networkmore » was generated for view of the gene expression architecture of 249 genes in 265 GCs. Finally, we applied a canonical discriminant analysis approach to identify a 53-gene signature and a prognostic scoring system was established based on a canonical discriminant function of 53 genes. The prognostic scores strongly predicted patients with GC to have either a poor or good OS. Our study raises the prospect that the practicality of GC patient prognosis can be assessed by this prognostic scoring system.« less

Effect of decreasing temperature on the strobilation of Aurelia sp.1

NASA Astrophysics Data System (ADS)

Shi, Yan; Yu, Zhigang; Zhen, Yu; Wang, Guoshan; Wang, Xungong; Mi, Tiezhu

2018-03-01

The worldwide proliferation of marine jellyfish has become a crucial ecological and social issue, and as a cosmopolitan species, Aurelia spp. have received increasing scientific attentions. In the present study, the responses of strobilation in Aurelia sp.1 to decreasing temperature were illuminated through the expression levels of the retinoid x receptor (RxR) gene and the gene encoding a secreted protein, CL390. We observed that a higher final temperature decreased the strobilation prophase and strobilation interphase periods, and the growth rate of the strobilae ratio increased with increasing CL390 gene expression. The ratio of strobilae at 12°C was highest, and the strobilae showed the higher releasing ratios at both 12°C and 16°C compared with those at 4°C and 8°C. Furthermore, more ephyrae were released at the higher final temperature. Additionally, up-regulation and down-regulation of the CL390 gene were observed in response to the four decreasing temperatures. Although the four CL390 gene transcript levels increased more significantly than the transcript levels of the RxR gene, similar trends were observed in both genes.

lpxC and yafS are the most suitable internal controls to normalize real time RT-qPCR expression in the phytopathogenic bacteria Dickeya dadantii.

PubMed

Hommais, Florence; Zghidi-Abouzid, Ouafa; Oger-Desfeux, Christine; Pineau-Chapelle, Emilie; Van Gijsegem, Frederique; Nasser, William; Reverchon, Sylvie

2011-01-01

Quantitative RT-PCR is the method of choice for studying, with both sensitivity and accuracy, the expression of genes. A reliable normalization of the data, using several reference genes, is critical for an accurate quantification of gene expression. Here, we propose a set of reference genes, of the phytopathogenic bacteria Dickeya dadantii and Pectobacterium atrosepticum, which are stable in a wide range of growth conditions. We extracted, from a D. dadantii micro-array transcript profile dataset comprising thirty-two different growth conditions, an initial set of 49 expressed genes with very low variation in gene expression. Out of these, we retained 10 genes representing different functional categories, different levels of expression (low, medium, and high) and with no systematic variation in expression correlating with growth conditions. We measured the expression of these reference gene candidates using quantitative RT-PCR in 50 different experimental conditions, mimicking the environment encountered by the bacteria in their host and directly during the infection process in planta. The two most stable genes (ABF-0017965 (lpxC) and ABF-0020529 (yafS) were successfully used for normalization of RT-qPCR data. Finally, we demonstrated that the ortholog of lpxC and yafS in Pectobacterium atrosepticum also showed stable expression in diverse growth conditions. We have identified at least two genes, lpxC (ABF-0017965) and yafS (ABF-0020509), whose expressions are stable in a wide range of growth conditions and during infection. Thus, these genes are considered suitable for use as reference genes for the normalization of real-time RT-qPCR data of the two main pectinolytic phytopathogenic bacteria D. dadantii and P. atrosepticum and, probably, of other Enterobacteriaceae. Moreover, we defined general criteria to select good reference genes in bacteria.

Transcriptomic information from Pacific white shrimp (Litopenaeus vannamei) ovary and eyestalk, and expression patterns for genes putatively involved in the reproductive process.

PubMed

Ventura-López, Claudia; Galindo-Torres, Pavel E; Arcos, Fabiola G; Galindo-Sánchez, Clara; Racotta, Ilie S; Escobedo-Fregoso, Cristina; Llera-Herrera, Raúl; Ibarra, Ana M

2017-05-15

The increased use of massive sequencing technologies has enabled the identification of several genes known to be involved in different mechanisms associated with reproduction that so far have only been studied in vertebrates and other model invertebrate species. In order to further investigate the genes involved in Litopenaeus vannamei reproduction, cDNA and SSH libraries derived from female eyestalk and gonad were produced, allowing the identification of expressed sequences tags (ESTs) that potentially have a role in the regulation of gonadal maturation. In the present study, different transcripts involved in reproduction were identified and a number of them were characterized as full-length. These transcripts were evaluated in males and females in order to establish their tissue expression profiles during developmental stages (juvenile, subadult and adult), and in the case of females, their possible association with gonad maturation was assessed through expression analysis of vitellogenin. The results indicated that the expression of vitellogenin receptor (vtgr) and minichromosome maintenance (mcm) family members in the female gonad suggest an important role during previtellogenesis. Additionally, the expression profiles of genes such as famet, igfbp and gpcr in brain tissues suggest an interaction between the insulin/insulin-like growth factor signaling pathway (IIS) and methyl farnesoate (MF) biosynthesis for control of reproduction. Furthermore, the specific expression pattern of farnesoic acid O-methyltransferase suggests that final synthesis of MF is carried out in different target tissues, where it is regulated by esterase enzymes under a tissue-specific hormonal control. Finally, the presence of a vertebrate type steroid receptor in hepatopancreas and intestine besides being highly expressed in female gonads, suggest a role of that receptor during sexual maturation. Copyright © 2016 Elsevier Inc. All rights reserved.

Development of an antibiotic marker-free platform for heterologous protein production in Streptomyces.

PubMed

Sevillano, Laura; Díaz, Margarita; Santamaría, Ramón I

2017-09-26

The industrial use of enzymes produced by microorganisms is continuously growing due to the need for sustainable solutions. Nevertheless, many of the plasmids used for recombinant production of proteins in bacteria are based on the use of antibiotic resistance genes as selection markers. The safety concerns and legal requirements surrounding the increased use of antibiotic resistance genes have made the development of new antibiotic-free approaches essential. In this work, a system completely free of antibiotic resistance genes and useful for the production of high yields of proteins in Streptomyces is described. This system is based on the separation of the two components of the yefM/yoeBsl (antitoxin/toxin) operon; the toxin (yoeBsl) gene, responsible for host death, is integrated into the genome and the antitoxin gene (yefMsl), which inactivates the toxin, is located in the expression plasmid. To develop this system, the toxin gene was integrated into the genome of a strain lacking the complete operon, and the antibiotic resistance gene integrated along with the toxin was eliminated by Cre recombinase to generate a final host strain free of any antibiotic resistance marker. In the same way, the antibiotic resistance gene from the final expression plasmid was removed by Dre recombinase. The usefulness of this system was analysed by checking the production of two hydrolases from different Streptomyces. Production of both proteins, with potential industrial use, was high and stable over time after strain storage and after serial subcultures. These results support the robustness and stability of the positive selection system developed. The total absence of antibiotic resistance genes makes this system a powerful tool for using Streptomyces as a host to produce proteins at the industrial level. This work is the first Streptomyces antibiotic marker-free system to be described. Graphical abstract Antibiotic marker-free platform for protein expression in Streptomyces. The antitoxin gene present in the expression plasmid counteracts the effect of the toxin gene in the genome. In absence of the expression plasmid, the toxin causes cell death ensuring that only plasmid-containing cells persist.

Genic insights from integrated human proteomics in GeneCards.

PubMed

Fishilevich, Simon; Zimmerman, Shahar; Kohn, Asher; Iny Stein, Tsippi; Olender, Tsviya; Kolker, Eugene; Safran, Marilyn; Lancet, Doron

2016-01-01

GeneCards is a one-stop shop for searchable human gene annotations (http://www.genecards.org/). Data are automatically mined from ∼120 sources and presented in an integrated web card for every human gene. We report the application of recent advances in proteomics to enhance gene annotation and classification in GeneCards. First, we constructed the Human Integrated Protein Expression Database (HIPED), a unified database of protein abundance in human tissues, based on the publically available mass spectrometry (MS)-based proteomics sources ProteomicsDB, Multi-Omics Profiling Expression Database, Protein Abundance Across Organisms and The MaxQuant DataBase. The integrated database, residing within GeneCards, compares favourably with its individual sources, covering nearly 90% of human protein-coding genes. For gene annotation and comparisons, we first defined a protein expression vector for each gene, based on normalized abundances in 69 normal human tissues. This vector is portrayed in the GeneCards expression section as a bar graph, allowing visual inspection and comparison. These data are juxtaposed with transcriptome bar graphs. Using the protein expression vectors, we further defined a pairwise metric that helps assess expression-based pairwise proximity. This new metric for finding functional partners complements eight others, including sharing of pathways, gene ontology (GO) terms and domains, implemented in the GeneCards Suite. In parallel, we calculated proteome-based differential expression, highlighting a subset of tissues that overexpress a gene and subserving gene classification. This textual annotation allows users of VarElect, the suite's next-generation phenotyper, to more effectively discover causative disease variants. Finally, we define the protein-RNA expression ratio and correlation as yet another attribute of every gene in each tissue, adding further annotative information. The results constitute a significant enhancement of several GeneCards sections and help promote and organize the genome-wide structural and functional knowledge of the human proteome. Database URL:http://www.genecards.org/. © The Author(s) 2016. Published by Oxford University Press.

Identification and validation of reference genes for quantitative real-time PCR normalization and its applications in lycium.

PubMed

Zeng, Shaohua; Liu, Yongliang; Wu, Min; Liu, Xiaomin; Shen, Xiaofei; Liu, Chunzhao; Wang, Ying

2014-01-01

Lycium barbarum and L. ruthenicum are extensively used as traditional Chinese medicinal plants. Next generation sequencing technology provides a powerful tool for analyzing transcriptomic profiles of gene expression in non-model species. Such gene expression can then be confirmed with quantitative real-time polymerase chain reaction (qRT-PCR). Therefore, use of systematically identified suitable reference genes is a prerequisite for obtaining reliable gene expression data. Here, we calculated the expression stability of 18 candidate reference genes across samples from different tissues and grown under salt stress using geNorm and NormFinder procedures. The geNorm-determined rank of reference genes was similar to those defined by NormFinder with some differences. Both procedures confirmed that the single most stable reference gene was ACNTIN1 for L. barbarum fruits, H2B1 for L. barbarum roots, and EF1α for L. ruthenicum fruits. PGK3, H2B2, and PGK3 were identified as the best stable reference genes for salt-treated L. ruthenicum leaves, roots, and stems, respectively. H2B1 and GAPDH1+PGK1 for L. ruthenicum and SAMDC2+H2B1 for L. barbarum were the best single and/or combined reference genes across all samples. Finally, expression of salt-responsive gene NAC, fruit ripening candidate gene LrPG, and anthocyanin genes were investigated to confirm the validity of the selected reference genes. Suitable reference genes identified in this study provide a foundation for accurately assessing gene expression and further better understanding of novel gene function to elucidate molecular mechanisms behind particular biological/physiological processes in Lycium.

Genome-wide profiling of gene expression in the epididymis of alpha-chlorohydrin-induced infertile rats using an oligonucleotide microarray

PubMed Central

2010-01-01

Background As one of the chlorinated antifertility compounds, alpha-chlorohydrin (ACH) can inhibit glyceraldehyde-3-phosphate dehydrogenase (G3PDH) activity in epididymal sperm and affect sperm energy metabolism, maturation and fertilization, eventually leading to male infertility. Further studies demonstrated that the inhibitory effect of ACH on G3PDH is not only confined to epididymal sperm but also to the epididymis. Moreover, little investigation on gene expression changes in the epididymis after ACH treatment has been conducted. Therefore, gene expression studies may indicate new epididymal targets related to sperm maturation and fertility through the analysis of ACH-treated infertile animals. Methods Rats were treated with ACH for ten consecutive days, and then each male rat copulated with two female rats in proestrus. Then sperm maturation and other fertility parameters were analyzed. Furthermore, we identified epididymal-specific genes that are associated with fertility between control and ACH groups using an Affymetrix Rat 230 2.0 oligo-microarray. Finally, we performed RT-PCR analysis for several differentially expressed genes to validate the alteration in gene expression observed by oligonucleotide microarray. Results Among all the differentially expressed genes, we analyzed and screened the down-regulated genes associated with metabolism processes, which are considered the major targets of ACH action. Simultaneously, the genes that were up-regulated by chlorohydrin were detected. The genes that negatively regulate sperm maturation and fertility include apoptosis and immune-related genes and have not been reported previously. The overall results of PCR analysis for selected genes were consistent with the array data. Conclusions In this study, we have described the genome-wide profiles of gene expression in the epididymides of infertile rats induced by ACH, which could become potential epididymal specific targets for male contraception and infertility treatment. PMID:20409345

Genome-wide profiling of gene expression in the epididymis of alpha-chlorohydrin-induced infertile rats using an oligonucleotide microarray.

PubMed

Xie, Shuwu; Zhu, Yan; Ma, Li; Lu, Yingying; Zhou, Jieyun; Gui, Youlun; Cao, Lin

2010-04-22

As one of the chlorinated antifertility compounds, alpha-chlorohydrin (ACH) can inhibit glyceraldehyde-3-phosphate dehydrogenase (G3PDH) activity in epididymal sperm and affect sperm energy metabolism, maturation and fertilization, eventually leading to male infertility. Further studies demonstrated that the inhibitory effect of ACH on G3PDH is not only confined to epididymal sperm but also to the epididymis. Moreover, little investigation on gene expression changes in the epididymis after ACH treatment has been conducted. Therefore, gene expression studies may indicate new epididymal targets related to sperm maturation and fertility through the analysis of ACH-treated infertile animals. Rats were treated with ACH for ten consecutive days, and then each male rat copulated with two female rats in proestrus. Then sperm maturation and other fertility parameters were analyzed. Furthermore, we identified epididymal-specific genes that are associated with fertility between control and ACH groups using an Affymetrix Rat 230 2.0 oligo-microarray. Finally, we performed RT-PCR analysis for several differentially expressed genes to validate the alteration in gene expression observed by oligonucleotide microarray. Among all the differentially expressed genes, we analyzed and screened the down-regulated genes associated with metabolism processes, which are considered the major targets of ACH action. Simultaneously, the genes that were up-regulated by chlorohydrin were detected. The genes that negatively regulate sperm maturation and fertility include apoptosis and immune-related genes and have not been reported previously. The overall results of PCR analysis for selected genes were consistent with the array data. In this study, we have described the genome-wide profiles of gene expression in the epididymides of infertile rats induced by ACH, which could become potential epididymal specific targets for male contraception and infertility treatment.

Association of genetic variants and expression levels of porcine FABP4 and FABP5 genes.

PubMed

Ballester, M; Puig-Oliveras, A; Castelló, A; Revilla, M; Fernández, A I; Folch, J M

2017-12-01

The FABP4 and FABP5 genes, coding for fatty acid transport proteins, have long been studied as positional candidate genes for SSC4 QTL affecting fat deposition and composition traits in pigs. Polymorphisms in these genes, FABP4:g.2634_2635insC and FABP5:g.3000T>G, have previously been associated with fatness traits in an Iberian by Landrace cross (IBMAP). The aim of the present work was to evaluate the functional implication of these genetic variants. For this purpose, FABP4 and FABP5 mRNA expression levels in 114 BC1_LD animals (25% Iberian × 75% Landrace) were analyzed using real-time quantitative PCR in backfat and muscle. FABP4 gene expression in backfat, but not in muscle, was associated with FABP4:g.2634_2635insC. In contrast, FABP5:g.3000T>G was not associated with gene expression levels. An expression-based genome-wide association study highlighted the FABP4:g.2634_2635insC polymorphism as the polymorphism most associated with FABP4 gene expression in backfat. Furthermore, other genomic regions associated in trans with the mRNA expression of FABP4 in backfat and FABP5 in muscle were also identified. Finally, two putative transcription binding sites for PPARG and NR4A2 may be affected by the FABP4:g.2634_2635insC polymorphism, modifying FABP4 gene expression. Our results reinforce FABP4 as a candidate gene for fatness traits on SSC4. © 2017 Stichting International Foundation for Animal Genetics.

SiBIC: a web server for generating gene set networks based on biclusters obtained by maximal frequent itemset mining.

PubMed

Takahashi, Kei-ichiro; Takigawa, Ichigaku; Mamitsuka, Hiroshi

2013-01-01

Detecting biclusters from expression data is useful, since biclusters are coexpressed genes under only part of all given experimental conditions. We present a software called SiBIC, which from a given expression dataset, first exhaustively enumerates biclusters, which are then merged into rather independent biclusters, which finally are used to generate gene set networks, in which a gene set assigned to one node has coexpressed genes. We evaluated each step of this procedure: 1) significance of the generated biclusters biologically and statistically, 2) biological quality of merged biclusters, and 3) biological significance of gene set networks. We emphasize that gene set networks, in which nodes are not genes but gene sets, can be more compact than usual gene networks, meaning that gene set networks are more comprehensible. SiBIC is available at http://utrecht.kuicr.kyoto-u.ac.jp:8080/miami/faces/index.jsp.

Manganese Superoxide Dismutase Gene Expression Is Induced by Nanog and Oct4, Essential Pluripotent Stem Cells' Transcription Factors.

PubMed

Solari, Claudia; Vázquez Echegaray, Camila; Cosentino, María Soledad; Petrone, María Victoria; Waisman, Ariel; Luzzani, Carlos; Francia, Marcos; Villodre, Emilly; Lenz, Guido; Miriuka, Santiago; Barañao, Lino; Guberman, Alejandra

2015-01-01

Pluripotent stem cells possess complex systems that protect them from oxidative stress and ensure genomic stability, vital for their role in development. Even though it has been reported that antioxidant activity diminishes along stem cell differentiation, little is known about the transcriptional regulation of the involved genes. The reported modulation of some of these genes led us to hypothesize that some of them could be regulated by the transcription factors critical for self-renewal and pluripotency in embryonic stem cells (ESCs) and in induced pluripotent stem cells (iPSCs). In this work, we studied the expression profile of multiple genes involved in antioxidant defense systems in both ESCs and iPSCs. We found that Manganese superoxide dismutase gene (Mn-Sod/Sod2) was repressed during diverse differentiation protocols showing an expression pattern similar to Nanog gene. Moreover, Sod2 promoter activity was induced by Oct4 and Nanog when we performed a transactivation assay using two different reporter constructions. Finally, we studied Sod2 gene regulation by modulating the expression of Oct4 and Nanog in ESCs by shRNAs and found that downregulation of any of them reduced Sod2 expression. Our results indicate that pluripotency transcription factors positively modulate Sod2 gene transcription.

Manganese Superoxide Dismutase Gene Expression Is Induced by Nanog and Oct4, Essential Pluripotent Stem Cells’ Transcription Factors

PubMed Central

Solari, Claudia; Vázquez Echegaray, Camila; Cosentino, María Soledad; Petrone, María Victoria; Waisman, Ariel; Luzzani, Carlos; Francia, Marcos; Villodre, Emilly; Lenz, Guido; Miriuka, Santiago; Barañao, Lino; Guberman, Alejandra

2015-01-01

Pluripotent stem cells possess complex systems that protect them from oxidative stress and ensure genomic stability, vital for their role in development. Even though it has been reported that antioxidant activity diminishes along stem cell differentiation, little is known about the transcriptional regulation of the involved genes. The reported modulation of some of these genes led us to hypothesize that some of them could be regulated by the transcription factors critical for self-renewal and pluripotency in embryonic stem cells (ESCs) and in induced pluripotent stem cells (iPSCs). In this work, we studied the expression profile of multiple genes involved in antioxidant defense systems in both ESCs and iPSCs. We found that Manganese superoxide dismutase gene (Mn-Sod/Sod2) was repressed during diverse differentiation protocols showing an expression pattern similar to Nanog gene. Moreover, Sod2 promoter activity was induced by Oct4 and Nanog when we performed a transactivation assay using two different reporter constructions. Finally, we studied Sod2 gene regulation by modulating the expression of Oct4 and Nanog in ESCs by shRNAs and found that downregulation of any of them reduced Sod2 expression. Our results indicate that pluripotency transcription factors positively modulate Sod2 gene transcription. PMID:26642061

Refinement of light-responsive transcript lists using rice oligonucleotide arrays: evaluation of gene-redundancy.

PubMed

Jung, Ki-Hong; Dardick, Christopher; Bartley, Laura E; Cao, Peijian; Phetsom, Jirapa; Canlas, Patrick; Seo, Young-Su; Shultz, Michael; Ouyang, Shu; Yuan, Qiaoping; Frank, Bryan C; Ly, Eugene; Zheng, Li; Jia, Yi; Hsia, An-Ping; An, Kyungsook; Chou, Hui-Hsien; Rocke, David; Lee, Geun Cheol; Schnable, Patrick S; An, Gynheung; Buell, C Robin; Ronald, Pamela C

2008-10-06

Studies of gene function are often hampered by gene-redundancy, especially in organisms with large genomes such as rice (Oryza sativa). We present an approach for using transcriptomics data to focus functional studies and address redundancy. To this end, we have constructed and validated an inexpensive and publicly available rice oligonucleotide near-whole genome array, called the rice NSF45K array. We generated expression profiles for light- vs. dark-grown rice leaf tissue and validated the biological significance of the data by analyzing sources of variation and confirming expression trends with reverse transcription polymerase chain reaction. We examined trends in the data by evaluating enrichment of gene ontology terms at multiple false discovery rate thresholds. To compare data generated with the NSF45K array with published results, we developed publicly available, web-based tools (www.ricearray.org). The Oligo and EST Anatomy Viewer enables visualization of EST-based expression profiling data for all genes on the array. The Rice Multi-platform Microarray Search Tool facilitates comparison of gene expression profiles across multiple rice microarray platforms. Finally, we incorporated gene expression and biochemical pathway data to reduce the number of candidate gene products putatively participating in the eight steps of the photorespiration pathway from 52 to 10, based on expression levels of putatively functionally redundant genes. We confirmed the efficacy of this method to cope with redundancy by correctly predicting participation in photorespiration of a gene with five paralogs. Applying these methods will accelerate rice functional genomics.

Knock-in strategy at 3'-end of Crx gene by CRISPR/Cas9 system shows the gene expression profiles during human photoreceptor differentiation.

PubMed

Homma, Kohei; Usui, Sumiko; Kaneda, Makoto

2017-03-01

Fluorescent reporter gene knock-in induced pluripotent stem cell (iPSC) lines have been used to evaluate the efficiency of differentiation into specific cell lineages. Here, we report a knock-in strategy for the generation of human iPSC reporter lines in which a 2A peptide sequence and a red fluorescent protein (E2-Crimson) gene were inserted at the termination codon of the cone-rod homeobox (Crx) gene, a photoreceptor-specific transcriptional factor gene. The knock-in iPSC lines were differentiated into fluorescence-expressing cells in 3D retinal differentiation culture, and the fluorescent cells also expressed Crx specifically in the nucleus. We found that the fluorescence intensity was positively correlated with the expression levels of Crx mRNA and that fluorescent cells expressed rod photoreceptor-specific genes in the later stage of differentiation. Finally, we treated the fluorescent cells with DAPT, a Notch inhibitor, and found that DAPT-enhanced retinal differentiation was associated with up-regulation of Crx, Otx2 and NeuroD1, and down-regulation of Hes5 and Ngn2. These suggest that this knock-in strategy at the 3'-end of the target gene, combined with the 2A peptide linked to fluorescent proteins, offers a useful tool for labeling specific cell lineages or monitoring expression of any marker genes without affecting the function of the target gene. © 2017 Molecular Biology Society of Japan and John Wiley & Sons Australia, Ltd.

Analysis of temporal gene expression profiles: clustering by simulated annealing and determining the optimal number of clusters.

PubMed

Lukashin, A V; Fuchs, R

2001-05-01

Cluster analysis of genome-wide expression data from DNA microarray hybridization studies has proved to be a useful tool for identifying biologically relevant groupings of genes and samples. In the present paper, we focus on several important issues related to clustering algorithms that have not yet been fully studied. We describe a simple and robust algorithm for the clustering of temporal gene expression profiles that is based on the simulated annealing procedure. In general, this algorithm guarantees to eventually find the globally optimal distribution of genes over clusters. We introduce an iterative scheme that serves to evaluate quantitatively the optimal number of clusters for each specific data set. The scheme is based on standard approaches used in regular statistical tests. The basic idea is to organize the search of the optimal number of clusters simultaneously with the optimization of the distribution of genes over clusters. The efficiency of the proposed algorithm has been evaluated by means of a reverse engineering experiment, that is, a situation in which the correct distribution of genes over clusters is known a priori. The employment of this statistically rigorous test has shown that our algorithm places greater than 90% genes into correct clusters. Finally, the algorithm has been tested on real gene expression data (expression changes during yeast cell cycle) for which the fundamental patterns of gene expression and the assignment of genes to clusters are well understood from numerous previous studies.

A Genome-Wide Screen Indicates Correlation between Differentiation and Expression of Metabolism Related Genes

PubMed Central

Shende, Akhilesh; Singh, Anupama; Meena, Anil; Ghosal, Ritika; Ranganathan, Madhav; Bandyopadhyay, Amitabha

2013-01-01

Differentiated tissues may be considered as materials with distinct properties. The differentiation program of a given tissue ensures that it acquires material properties commensurate with its function. It may be hypothesized that some of these properties are acquired through production of tissue-specific metabolites synthesized by metabolic enzymes. To establish correlation between metabolism and organogenesis we have carried out a genome-wide expression study of metabolism related genes by RNA in-situ hybridization. 23% of the metabolism related genes studied are expressed in a tissue-restricted but not tissue-exclusive manner. We have conducted the screen on whole mount chicken (Gallus gallus) embryos from four distinct developmental stages to correlate dynamic changes in expression patterns of metabolic enzymes with spatio-temporally unique developmental events. Our data strongly suggests that unique combinations of metabolism related genes, and not specific metabolic pathways, are upregulated during differentiation. Further, expression of metabolism related genes in well established signaling centers that regulate different aspects of morphogenesis indicates developmental roles of some of the metabolism related genes. The database of tissue-restricted expression patterns of metabolism related genes, generated in this study, should serve as a resource for systematic identification of these genes with tissue-specific functions during development. Finally, comprehensive understanding of differentiation is not possible unless the downstream genes of a differentiation cascade are identified. We propose, metabolic enzymes constitute a significant portion of these downstream target genes. Thus our study should help elucidate different aspects of tissue differentiation. PMID:23717462

The evolution of duplicate gene expression in mammalian organs

PubMed Central

Guschanski, Katerina; Warnefors, Maria; Kaessmann, Henrik

2017-01-01

Gene duplications generate genomic raw material that allows the emergence of novel functions, likely facilitating adaptive evolutionary innovations. However, global assessments of the functional and evolutionary relevance of duplicate genes in mammals were until recently limited by the lack of appropriate comparative data. Here, we report a large-scale study of the expression evolution of DNA-based functional gene duplicates in three major mammalian lineages (placental mammals, marsupials, egg-laying monotremes) and birds, on the basis of RNA sequencing (RNA-seq) data from nine species and eight organs. We observe dynamic changes in tissue expression preference of paralogs with different duplication ages, suggesting differential contribution of paralogs to specific organ functions during vertebrate evolution. Specifically, we show that paralogs that emerged in the common ancestor of bony vertebrates are enriched for genes with brain-specific expression and provide evidence for differential forces underlying the preferential emergence of young testis- and liver-specific expressed genes. Further analyses uncovered that the overall spatial expression profiles of gene families tend to be conserved, with several exceptions of pronounced tissue specificity shifts among lineage-specific gene family expansions. Finally, we trace new lineage-specific genes that may have contributed to the specific biology of mammalian organs, including the little-studied placenta. Overall, our study provides novel and taxonomically broad evidence for the differential contribution of duplicate genes to tissue-specific transcriptomes and for their importance for the phenotypic evolution of vertebrates. PMID:28743766

A genome-wide screen indicates correlation between differentiation and expression of metabolism related genes.

PubMed

Roy, Priti; Kumar, Brijesh; Shende, Akhilesh; Singh, Anupama; Meena, Anil; Ghosal, Ritika; Ranganathan, Madhav; Bandyopadhyay, Amitabha

2013-01-01

Differentiated tissues may be considered as materials with distinct properties. The differentiation program of a given tissue ensures that it acquires material properties commensurate with its function. It may be hypothesized that some of these properties are acquired through production of tissue-specific metabolites synthesized by metabolic enzymes. To establish correlation between metabolism and organogenesis we have carried out a genome-wide expression study of metabolism related genes by RNA in-situ hybridization. 23% of the metabolism related genes studied are expressed in a tissue-restricted but not tissue-exclusive manner. We have conducted the screen on whole mount chicken (Gallus gallus) embryos from four distinct developmental stages to correlate dynamic changes in expression patterns of metabolic enzymes with spatio-temporally unique developmental events. Our data strongly suggests that unique combinations of metabolism related genes, and not specific metabolic pathways, are upregulated during differentiation. Further, expression of metabolism related genes in well established signaling centers that regulate different aspects of morphogenesis indicates developmental roles of some of the metabolism related genes. The database of tissue-restricted expression patterns of metabolism related genes, generated in this study, should serve as a resource for systematic identification of these genes with tissue-specific functions during development. Finally, comprehensive understanding of differentiation is not possible unless the downstream genes of a differentiation cascade are identified. We propose, metabolic enzymes constitute a significant portion of these downstream target genes. Thus our study should help elucidate different aspects of tissue differentiation.

Spatial differentiation of gene expression in Aspergillus niger colony grown for sugar beet pulp utilization

PubMed Central

Benoit, Isabelle; Zhou, Miaomiao; Vivas Duarte, Alexandra; Downes, Damien J.; Todd, Richard B.; Kloezen, Wendy; Post, Harm; Heck, Albert J. R.; Maarten Altelaar, A. F.; de Vries, Ronald P.

2015-01-01

Degradation of plant biomass to fermentable sugars is of critical importance for the use of plant materials for biofuels. Filamentous fungi are ubiquitous organisms and major plant biomass degraders. Single colonies of some fungal species can colonize massive areas as large as five soccer stadia. During growth, the mycelium encounters heterogeneous carbon sources. Here we assessed whether substrate heterogeneity is a major determinant of spatial gene expression in colonies of Aspergillus niger. We analyzed whole-genome gene expression in five concentric zones of 5-day-old colonies utilizing sugar beet pulp as a complex carbon source. Growth, protein production and secretion occurred throughout the colony. Genes involved in carbon catabolism were expressed uniformly from the centre to the periphery whereas genes encoding plant biomass degrading enzymes and nitrate utilization were expressed differentially across the colony. A combined adaptive response of carbon-catabolism and enzyme production to locally available monosaccharides was observed. Finally, our results demonstrate that A. niger employs different enzymatic tools to adapt its metabolism as it colonizes complex environments. PMID:26314379

Spatial differentiation of gene expression in Aspergillus niger colony grown for sugar beet pulp utilization.

PubMed

Benoit, Isabelle; Zhou, Miaomiao; Vivas Duarte, Alexandra; Downes, Damien J; Todd, Richard B; Kloezen, Wendy; Post, Harm; Heck, Albert J R; Maarten Altelaar, A F; de Vries, Ronald P

2015-08-28

Degradation of plant biomass to fermentable sugars is of critical importance for the use of plant materials for biofuels. Filamentous fungi are ubiquitous organisms and major plant biomass degraders. Single colonies of some fungal species can colonize massive areas as large as five soccer stadia. During growth, the mycelium encounters heterogeneous carbon sources. Here we assessed whether substrate heterogeneity is a major determinant of spatial gene expression in colonies of Aspergillus niger. We analyzed whole-genome gene expression in five concentric zones of 5-day-old colonies utilizing sugar beet pulp as a complex carbon source. Growth, protein production and secretion occurred throughout the colony. Genes involved in carbon catabolism were expressed uniformly from the centre to the periphery whereas genes encoding plant biomass degrading enzymes and nitrate utilization were expressed differentially across the colony. A combined adaptive response of carbon-catabolism and enzyme production to locally available monosaccharides was observed. Finally, our results demonstrate that A. niger employs different enzymatic tools to adapt its metabolism as it colonizes complex environments.

An effective fuzzy kernel clustering analysis approach for gene expression data.

PubMed

Sun, Lin; Xu, Jiucheng; Yin, Jiaojiao

2015-01-01

Fuzzy clustering is an important tool for analyzing microarray data. A major problem in applying fuzzy clustering method to microarray gene expression data is the choice of parameters with cluster number and centers. This paper proposes a new approach to fuzzy kernel clustering analysis (FKCA) that identifies desired cluster number and obtains more steady results for gene expression data. First of all, to optimize characteristic differences and estimate optimal cluster number, Gaussian kernel function is introduced to improve spectrum analysis method (SAM). By combining subtractive clustering with max-min distance mean, maximum distance method (MDM) is proposed to determine cluster centers. Then, the corresponding steps of improved SAM (ISAM) and MDM are given respectively, whose superiority and stability are illustrated through performing experimental comparisons on gene expression data. Finally, by introducing ISAM and MDM into FKCA, an effective improved FKCA algorithm is proposed. Experimental results from public gene expression data and UCI database show that the proposed algorithms are feasible for cluster analysis, and the clustering accuracy is higher than the other related clustering algorithms.

MicroRNAs shape circadian hepatic gene expression on a transcriptome-wide scale

PubMed Central

Du, Ngoc-Hien; Arpat, Alaaddin Bulak; De Matos, Mara; Gatfield, David

2014-01-01

A considerable proportion of mammalian gene expression undergoes circadian oscillations. Post-transcriptional mechanisms likely make important contributions to mRNA abundance rhythms. We have investigated how microRNAs (miRNAs) contribute to core clock and clock-controlled gene expression using mice in which miRNA biogenesis can be inactivated in the liver. While the hepatic core clock was surprisingly resilient to miRNA loss, whole transcriptome sequencing uncovered widespread effects on clock output gene expression. Cyclic transcription paired with miRNA-mediated regulation was thus identified as a frequent phenomenon that affected up to 30% of the rhythmic transcriptome and served to post-transcriptionally adjust the phases and amplitudes of rhythmic mRNA accumulation. However, only few mRNA rhythms were actually generated by miRNAs. Overall, our study suggests that miRNAs function to adapt clock-driven gene expression to tissue-specific requirements. Finally, we pinpoint several miRNAs predicted to act as modulators of rhythmic transcripts, and identify rhythmic pathways particularly prone to miRNA regulation. DOI: http://dx.doi.org/10.7554/eLife.02510.001 PMID:24867642

TRACING CO-REGULATORY NETWORK DYNAMICS IN NOISY, SINGLE-CELL TRANSCRIPTOME TRAJECTORIES.

PubMed

Cordero, Pablo; Stuart, Joshua M

2017-01-01

The availability of gene expression data at the single cell level makes it possible to probe the molecular underpinnings of complex biological processes such as differentiation and oncogenesis. Promising new methods have emerged for reconstructing a progression 'trajectory' from static single-cell transcriptome measurements. However, it remains unclear how to adequately model the appreciable level of noise in these data to elucidate gene regulatory network rewiring. Here, we present a framework called Single Cell Inference of MorphIng Trajectories and their Associated Regulation (SCIMITAR) that infers progressions from static single-cell transcriptomes by employing a continuous parametrization of Gaussian mixtures in high-dimensional curves. SCIMITAR yields rich models from the data that highlight genes with expression and co-expression patterns that are associated with the inferred progression. Further, SCIMITAR extracts regulatory states from the implicated trajectory-evolvingco-expression networks. We benchmark the method on simulated data to show that it yields accurate cell ordering and gene network inferences. Applied to the interpretation of a single-cell human fetal neuron dataset, SCIMITAR finds progression-associated genes in cornerstone neural differentiation pathways missed by standard differential expression tests. Finally, by leveraging the rewiring of gene-gene co-expression relations across the progression, the method reveals the rise and fall of co-regulatory states and trajectory-dependent gene modules. These analyses implicate new transcription factors in neural differentiation including putative co-factors for the multi-functional NFAT pathway.

The Prx1 limb enhancers: targeted gene expression in developing zebrafish pectoral fins.

PubMed

Hernández-Vega, Amayra; Minguillón, Carolina

2011-08-01

Limbs represent an excellent model to study the induction, growth, and patterning of several organs. A breakthrough to study gene function in various tissues has been the characterization of regulatory elements that allow tissue-specific interference of gene function. The mouse Prx1 promoter has been used to generate limb-specific mutants and overexpress genes in tetrapod limbs. Although zebrafish possess advantages that favor their use to study limb morphogenesis, there is no driver described suitable for specifically interfering with gene function in developing fins. We report the generation of zebrafish lines that express enhanced green fluorescent protein (EGFP) driven by the mouse Prx1 enhancer in developing pectoral fins. We also describe the expression pattern of the zebrafish prrx1 genes and identify three conserved non-coding elements (CNEs) that we use to generate fin-specific EGFP reporter lines. Finally, we show that the mouse and zebrafish regulatory elements may be used to modify gene function in pectoral fins. Copyright © 2011 Wiley-Liss, Inc.

Canonical Genetic Signatures of the Adult Human Brain

PubMed Central

Hawrylycz, Michael; Miller, Jeremy A.; Menon, Vilas; Feng, David; Dolbeare, Tim; Guillozet-Bongaarts, Angela L.; Jegga, Anil G.; Aronow, Bruce J.; Lee, Chang-Kyu; Bernard, Amy; Glasser, Matthew F.; Dierker, Donna L.; Menche, Jörge; Szafer, Aaron; Collman, Forrest; Grange, Pascal; Berman, Kenneth A.; Mihalas, Stefan; Yao, Zizhen; Stewart, Lance; Barabási, Albert-László; Schulkin, Jay; Phillips, John; Ng, Lydia; Dang, Chinh; Haynor, David R.; Jones, Allan; Van Essen, David C.; Koch, Christof; Lein, Ed

2015-01-01

The structure and function of the human brain are highly stereotyped, implying a conserved molecular program responsible for its development, cellular structure, and function. We applied a correlation-based metric of “differential stability” (DS) to assess reproducibility of gene expression patterning across 132 structures in six individual brains, revealing meso-scale genetic organization. The highest DS genes are highly biologically relevant, with enrichment for brain-related biological annotations, disease associations, drug targets, and literature citations. Using high DS genes we identified 32 anatomically diverse and reproducible gene expression signatures, which represent distinct cell types, intracellular components, and/or associations with neurodevelopmental and neurodegenerative disorders. Genes in neuron-associated compared to non-neuronal networks showed higher preservation between human and mouse; however, many diversely-patterned genes displayed dramatic shifts in regulation between species. Finally, highly consistent transcriptional architecture in neocortex is correlated with resting state functional connectivity, suggesting a link between conserved gene expression and functionally relevant circuitry. PMID:26571460

Superoxide radical-generating compounds activate a predicted promoter site for paraquat-inducible genes of the Chromobacterium violaceum bacterium in a dose-dependent manner.

PubMed

Gabriel, J E; Guerra-Slompo, E P; de Souza, E M; de Carvalho, F A L; Madeira, H M F; de Vasconcelos, A T R

2015-08-21

The purpose of the present study was to functionally evaluate the influence of superoxide radical-generating compounds on the heterologous induction of a predicted promoter region of open reading frames for paraquat-inducible genes (pqi genes) revealed during genome annotation analyses of the Chromobacterium violaceum bacterium. A 388-bp fragment corresponding to a pqi gene promoter of C. violaceum was amplified using specific primers and cloned into a conjugative vector containing the Escherichia coli lacZ gene without a promoter. Assessments of the expression of the β-galactosidase enzyme were performed in the presence of menadione (MEN) and phenazine methosulfate (PMS) compounds at different final concentrations to evaluate the heterologous activation of the predicted promoter region of interest in C. violaceum induced by these substrates. Under these experimental conditions, the MEN reagent promoted highly significant increases in the expression of the β-galactosidase enzyme modulated by activating the promoter region of the pqi genes at all concentrations tested. On the other hand, significantly higher levels in the expression of the β-galactosidase enzyme were detected exclusively in the presence of the PMS reagent at a final concentration of 50 μg/mL. The findings described in the present study demonstrate that superoxide radical-generating compounds can activate a predicted promoter DNA motif for pqi genes of the C. violaceum bacterium in a dose-dependent manner.

Hypergravity-induced changes in gene expression in Arabidopsis hypocotyls

NASA Astrophysics Data System (ADS)

Yoshioka, R.; Soga, K.; Wakabayashi, K.; Takeba, G.; Hoson, T.

2003-05-01

Under hypergravity conditions, the cell wall of stem organs becomes mechanically rigid and elongation growth is suppressed, which can be recognized as the mechanism for plants to resist gravitational force. The changes in gene expression by hypergravity treatment were analyzed in Arabidopsis hypocotyls by the differential display method, for identifying genes involved in hypergravity-induced growth suppression. Sixty-two cDNA clones were expressed differentially between the control and 300 g conditions: the expression levels of 39 clones increased, whereas those of 23 clones decreased under hypergravity conditions. Sequence analysis and database searching revealed that 12 clones, 9 up-regulated and 3 down-regulated, have homology to known proteins. The expression of these genes was further analyzed using RT-PCR. Finally, six genes were confirmed to be up-regulated by hypergravity. One of such genes encoded 3-hydroxy-3-methylglutaryl-Coenzyme A reductase (HMGR), which catalyzes a reaction producing mevalonic acid, a key precursor ofterpenoids such as membrane sterols and several types of hormones. The expression of HMGR gene increased within several hours after hypergravity treatment. Also, compactin, an inhibitor of HMGR, prevented hypergravity-induced growth suppression, suggesting that HMGR is involved in suppression of Arabidopsis hypocotyl growth by hypergravity. In addition, hypergravity increased the expression levels of genes encoding CCR1 and ERD15, which were shown to take part in the signaling pathway of environmental stimuli such as temperature and water, and those of the α-tubulin gene. These genes may be involved in a series of cellular events leading to growth suppression of stem organs under hypergravity conditions.

Function and Evolution of DNA Methylation in Nasonia vitripennis

PubMed Central

Wang, Xu; Wheeler, David; Avery, Amanda; Rago, Alfredo; Choi, Jeong-Hyeon; Colbourne, John K.; Clark, Andrew G.; Werren, John H.

2013-01-01

The parasitoid wasp Nasonia vitripennis is an emerging genetic model for functional analysis of DNA methylation. Here, we characterize genome-wide methylation at a base-pair resolution, and compare these results to gene expression across five developmental stages and to methylation patterns reported in other insects. An accurate assessment of DNA methylation across the genome is accomplished using bisulfite sequencing of adult females from a highly inbred line. One-third of genes show extensive methylation over the gene body, yet methylated DNA is not found in non-coding regions and rarely in transposons. Methylated genes occur in small clusters across the genome. Methylation demarcates exon-intron boundaries, with elevated levels over exons, primarily in the 5′ regions of genes. It is also elevated near the sites of translational initiation and termination, with reduced levels in 5′ and 3′ UTRs. Methylated genes have higher median expression levels and lower expression variation across development stages than non-methylated genes. There is no difference in frequency of differential splicing between methylated and non-methylated genes, and as yet no established role for methylation in regulating alternative splicing in Nasonia. Phylogenetic comparisons indicate that many genes maintain methylation status across long evolutionary time scales. Nasonia methylated genes are more likely to be conserved in insects, but even those that are not conserved show broader expression across development than comparable non-methylated genes. Finally, examination of duplicated genes shows that those paralogs that have lost methylation in the Nasonia lineage following gene duplication evolve more rapidly, show decreased median expression levels, and increased specialization in expression across development. Methylation of Nasonia genes signals constitutive transcription across developmental stages, whereas non-methylated genes show more dynamic developmental expression patterns. We speculate that loss of methylation may result in increased developmental specialization in evolution and acquisition of methylation may lead to broader constitutive expression. PMID:24130511

Transcriptome dynamics along axolotl regenerative development are consistent with an extensive reduction in gene expression heterogeneity in dedifferentiated cells

PubMed Central

2017-01-01

Although in recent years the study of gene expression variation in the absence of genetic or environmental cues or gene expression heterogeneity has intensified considerably, many basic and applied biological fields still remain unaware of how useful the study of gene expression heterogeneity patterns might be for the characterization of biological systems and/or processes. Largely based on the modulator effect chromatin compaction has for gene expression heterogeneity and the extensive changes in chromatin compaction known to occur for specialized cells that are naturally or artificially induced to revert to less specialized states or dedifferentiate, I recently hypothesized that processes that concur with cell dedifferentiation would show an extensive reduction in gene expression heterogeneity. The confirmation of the existence of such trend could be of wide interest because of the biomedical and biotechnological relevance of cell dedifferentiation-based processes, i.e., regenerative development, cancer, human induced pluripotent stem cells, or plant somatic embryogenesis. Here, I report the first empirical evidence consistent with the existence of an extensive reduction in gene expression heterogeneity for processes that concur with cell dedifferentiation by analyzing transcriptome dynamics along forearm regenerative development in Ambystoma mexicanum or axolotl. Also, I briefly discuss on the utility of the study of gene expression heterogeneity dynamics might have for the characterization of cell dedifferentiation-based processes, and the engineering of tools that afforded better monitoring and modulating such processes. Finally, I reflect on how a transitional reduction in gene expression heterogeneity for dedifferentiated cells can promote a long-term increase in phenotypic heterogeneity following cell dedifferentiation with potential adverse effects for biomedical and biotechnological applications. PMID:29134148

Gene expression and molecular phylogenetic analyses of beta-glucosidase in the termite Reticulitermes speratus (Isoptera: Rhinotermitidae).

PubMed

Shimada, Keisuke; Maekawa, Kiyoto

2014-06-01

Beta-glucosidase (BG) is known as a multifunctional enzyme for social maintenance in terms of both cellulose digestion and social communication in termites. However, the expression profiles of each BG gene and their evolutionary history are not well understood. First, we cloned two types of BG homologs (RsBGI and RsBGII) from the termite Reticulitermes speratus (Kolbe). Gene expression analyses showed that RsBGI expression levels of primary queens and kings from 30 to 100 days after colony foundation were high, but those of reproductives dropped after day 400. Extremely low gene expression levels of RsBGI were observed in eggs, whereas workers had significantly higher expression levels than those of soldiers and other colony members. Consequently, RsBGI gene expression levels changed among each developmental stage, and RsBGI was shown to be involved in cellulose digestion. On the other hand, the RsBGII gene was consistently expressed in all castes and developmental stages examined, and notable expression changes were not observed among them, including in eggs. It was indicated that RsBGII is a main component involved in social communication, for example, the egg-recognition pheromone shown in this species previously. Finally, we obtained partial gene homologs from other termite and cockroach species, including the woodroach (genus Cryptocercus), which is the sister group to termites, and performed molecular phylogenetic analyses. The results showed that the origin of the BG gene homologs preceded the divergence of termites and cockroaches, suggesting that the acquisition of multifunctionality of the BG gene also occurred in cockroach lineages. Copyright © 2014 Elsevier Ltd. All rights reserved.

REDD1 induction regulates the skeletal muscle gene expression signature following acute aerobic exercise.

PubMed

Gordon, Bradley S; Steiner, Jennifer L; Rossetti, Michael L; Qiao, Shuxi; Ellisen, Leif W; Govindarajan, Subramaniam S; Eroshkin, Alexey M; Williamson, David L; Coen, Paul M

2017-12-01

The metabolic stress placed on skeletal muscle by aerobic exercise promotes acute and long-term health benefits in part through changes in gene expression. However, the transducers that mediate altered gene expression signatures have not been completely elucidated. Regulated in development and DNA damage 1 (REDD1) is a stress-induced protein whose expression is transiently increased in skeletal muscle following acute aerobic exercise. However, the role of this induction remains unclear. Because REDD1 altered gene expression in other model systems, we sought to determine whether REDD1 induction following acute exercise altered the gene expression signature in muscle. To do this, wild-type and REDD1-null mice were randomized to remain sedentary or undergo a bout of acute treadmill exercise. Exercised mice recovered for 1, 3, or 6 h before euthanization. Acute exercise induced a transient increase in REDD1 protein expression within the plantaris only at 1 h postexercise, and the induction occurred in both cytosolic and nuclear fractions. At this time point, global changes in gene expression were surveyed using microarray. REDD1 induction was required for the exercise-induced change in expression of 24 genes. Validation by RT-PCR confirmed that the exercise-mediated changes in genes related to exercise capacity, muscle protein metabolism, neuromuscular junction remodeling, and Metformin action were negated in REDD1-null mice. Finally, the exercise-mediated induction of REDD1 was partially dependent upon glucocorticoid receptor activation. In all, these data show that REDD1 induction regulates the exercise-mediated change in a distinct set of genes within skeletal muscle. Copyright © 2017 the American Physiological Society.

Identification of differentially expressed genes through RNA sequencing in goats (Capra hircus) at different postnatal stages

PubMed Central

Li, Qian; Lin, Sen

2017-01-01

Intramuscular fat (IMF) content and fatty acid composition of longissimus dorsi muscle (LM) change with growth, which partially determines the flavor and nutritional value of goat (Capra hircus) meat. However, unlike cattle, little information is available on the transcriptome-wide changes during different postnatal stages in small ruminants, especially goats. In this study, the sequencing reads of goat LM tissues collected from kid, youth, and adult period were mapped to the goat genome. Results showed that out of total 24 689 Unigenes, 20 435 Unigenes were annotated. Based on expected number of fragments per kilobase of transcript sequence per million base pairs sequenced (FPKM), 111 annotated differentially expressed genes (DEGs) were identified among different postnatal stages, which were subsequently assigned to 16 possible expression patterns by series-cluster analysis. Functional classification by Gene Ontology (GO) analysis was used for selecting the genes showing highest expression related to lipid metabolism. Finally, we identified the node genes for lipid metabolism regulation using co-expression analysis. In conclusion, these data may uncover candidate genes having functional roles in regulation of goat muscle development and lipid metabolism during the various growth stages in goats. PMID:28800357

Identification of differentially expressed genes through RNA sequencing in goats (Capra hircus) at different postnatal stages.

PubMed

Lin, Yaqiu; Zhu, Jiangjiang; Wang, Yong; Li, Qian; Lin, Sen

2017-01-01

Intramuscular fat (IMF) content and fatty acid composition of longissimus dorsi muscle (LM) change with growth, which partially determines the flavor and nutritional value of goat (Capra hircus) meat. However, unlike cattle, little information is available on the transcriptome-wide changes during different postnatal stages in small ruminants, especially goats. In this study, the sequencing reads of goat LM tissues collected from kid, youth, and adult period were mapped to the goat genome. Results showed that out of total 24 689 Unigenes, 20 435 Unigenes were annotated. Based on expected number of fragments per kilobase of transcript sequence per million base pairs sequenced (FPKM), 111 annotated differentially expressed genes (DEGs) were identified among different postnatal stages, which were subsequently assigned to 16 possible expression patterns by series-cluster analysis. Functional classification by Gene Ontology (GO) analysis was used for selecting the genes showing highest expression related to lipid metabolism. Finally, we identified the node genes for lipid metabolism regulation using co-expression analysis. In conclusion, these data may uncover candidate genes having functional roles in regulation of goat muscle development and lipid metabolism during the various growth stages in goats.

Transcriptome analysis of the painted lady butterfly, Vanessa cardui during wing color pattern development.

PubMed

Connahs, Heidi; Rhen, Turk; Simmons, Rebecca B

2016-03-31

Butterfly wing color patterns are an important model system for understanding the evolution and development of morphological diversity and animal pigmentation. Wing color patterns develop from a complex network composed of highly conserved patterning genes and pigmentation pathways. Patterning genes are involved in regulating pigment synthesis however the temporal expression dynamics of these interacting networks is poorly understood. Here, we employ next generation sequencing to examine expression patterns of the gene network underlying wing development in the nymphalid butterfly, Vanessa cardui. We identified 9, 376 differentially expressed transcripts during wing color pattern development, including genes involved in patterning, pigmentation and gene regulation. Differential expression of these genes was highest at the pre-ommochrome stage compared to early pupal and late melanin stages. Overall, an increasing number of genes were down-regulated during the progression of wing development. We observed dynamic expression patterns of a large number of pigment genes from the ommochrome, melanin and also pteridine pathways, including contrasting patterns of expression for paralogs of the yellow gene family. Surprisingly, many patterning genes previously associated with butterfly pattern elements were not significantly up-regulated at any time during pupation, although many other transcription factors were differentially expressed. Several genes involved in Notch signaling were significantly up-regulated during the pre-ommochrome stage including slow border cells, bunched and pebbles; the function of these genes in the development of butterfly wings is currently unknown. Many genes involved in ecdysone signaling were also significantly up-regulated during early pupal and late melanin stages and exhibited opposing patterns of expression relative to the ecdysone receptor. Finally, a comparison across four butterfly transcriptomes revealed 28 transcripts common to all four species that have no known homologs in other metazoans. This study provides a comprehensive list of differentially expressed transcripts during wing development, revealing potential candidate genes that may be involved in regulating butterfly wing patterns. Some differentially expressed genes have no known homologs possibly representing genes unique to butterflies. Results from this study also indicate that development of nymphalid wing patterns may arise not only from melanin and ommochrome pigments but also the pteridine pigment pathway.

Cytoskeletal proteins and stem cell markers gene expression in human bone marrow mesenchymal stromal cells after different periods of simulated microgravity

NASA Astrophysics Data System (ADS)

Gershovich, P. M.; Gershovich, J. G.; Zhambalova, A. P.; Romanov, Yu. A.; Buravkova, L. B.

2012-01-01

Mesenchymal stem (stromal) cells (MSCs) are present in a variety of tissues during prenatal and postnatal human development. In adult organism, they are prevalent in bone marrow and supposed to be involved in space-flight induced osteopenia. We studied expression of various genes in human bone marrow MSCs after different terms of simulated microgravity (SMG) provided by Random Positioning Machine. Simulated microgravity induced transient changes in expression level of genes associated with actin cytoskeleton, especially after 48 h of SMG. However, after 120 h exposure in SMG partial restoration of gene expression levels (relative to the control) was found. Similar results were obtained with bmMSCs subjected to 24 h readaptation in static state after 24 h in SMG. Analysis of 84 genes related to identification, growth and differentiation of stem cells revealed that expression of nine genes was changed slightly after 48 h in SMG. More pronounced changes in gene expression of "stem cells markers" were observed after 120 h of simulated microgravity. Among 84 investigated genes, 30 were up-regulated and 24 were down-regulated. Finally, MSCs osteogenesis induced by long-term (10-20 days) simulation of microgravity was accompanied by down-regulation of gene expression of the main osteogenic differentiation markers ( ALPL, OMD) and master transcription osteogenic factor of MSCs ( Runx2). Thus, our study demonstrated that changes in expression level of some genes associated with actin cytoskeleton and stem cell markers are supposed to be one of the mechanisms, which contribute to precursor's cellular adaptation to the microgravity conditions. These results can clarify genomic mechanisms through which SMG reduces osteogenic differentiation of bmMSCs.

Drought responsive gene expression regulatory divergence between upland and lowland ecotypes of a perennial C4 grass.

PubMed

Lovell, John T; Schwartz, Scott; Lowry, David B; Shakirov, Eugene V; Bonnette, Jason E; Weng, Xiaoyu; Wang, Mei; Johnson, Jenifer; Sreedasyam, Avinash; Plott, Christopher; Jenkins, Jerry; Schmutz, Jeremy; Juenger, Thomas E

2016-04-01

Climatic adaptation is an example of a genotype-by-environment interaction (G×E) of fitness. Selection upon gene expression regulatory variation can contribute to adaptive phenotypic diversity; however, surprisingly few studies have examined how genome-wide patterns of gene expression G×E are manifested in response to environmental stress and other selective agents that cause climatic adaptation. Here, we characterize drought-responsive expression divergence between upland (drought-adapted) and lowland (mesic) ecotypes of the perennial C4 grass,Panicum hallii, in natural field conditions. Overall, we find that cis-regulatory elements contributed to gene expression divergence across 47% of genes, 7.2% of which exhibit drought-responsive G×E. While less well-represented, we observe 1294 genes (7.8%) with transeffects.Trans-by-environment interactions are weaker and much less common than cis G×E, occurring in only 0.7% oft rans-regulated genes. Finally, gene expression heterosis is highly enriched in expression phenotypes with significant G×E. As such, modes of inheritance that drive heterosis, such as dominance or overdominance, may be common among G×E genes. Interestingly, motifs specific to drought-responsive transcription factors are highly enriched in the promoters of genes exhibiting G×E and transregulation, indicating that expression G×E and heterosis may result from the evolution of transcription factors or their binding sites.P. hallii serves as the genomic model for its close relative and emerging biofuel crop, switchgrass (Panicum virgatum). Accordingly, the results here not only aid in the discovery of the genetic mechanisms that underlie local adaptation but also provide a foundation to improve switchgrass yield under water-limited conditions. © 2016 Lovell et al.; Published by Cold Spring Harbor Laboratory Press.

Drought responsive gene expression regulatory divergence between upland and lowland ecotypes of a perennial C4 grass

PubMed Central

Lovell, John T.; Schwartz, Scott; Lowry, David B.; Shakirov, Eugene V.; Bonnette, Jason E.; Weng, Xiaoyu; Wang, Mei; Johnson, Jenifer; Sreedasyam, Avinash; Plott, Christopher; Jenkins, Jerry; Schmutz, Jeremy; Juenger, Thomas E.

2016-01-01

Climatic adaptation is an example of a genotype-by-environment interaction (G×E) of fitness. Selection upon gene expression regulatory variation can contribute to adaptive phenotypic diversity; however, surprisingly few studies have examined how genome-wide patterns of gene expression G×E are manifested in response to environmental stress and other selective agents that cause climatic adaptation. Here, we characterize drought-responsive expression divergence between upland (drought-adapted) and lowland (mesic) ecotypes of the perennial C4 grass, Panicum hallii, in natural field conditions. Overall, we find that cis-regulatory elements contributed to gene expression divergence across 47% of genes, 7.2% of which exhibit drought-responsive G×E. While less well-represented, we observe 1294 genes (7.8%) with trans effects. Trans-by-environment interactions are weaker and much less common than cis G×E, occurring in only 0.7% of trans-regulated genes. Finally, gene expression heterosis is highly enriched in expression phenotypes with significant G×E. As such, modes of inheritance that drive heterosis, such as dominance or overdominance, may be common among G×E genes. Interestingly, motifs specific to drought-responsive transcription factors are highly enriched in the promoters of genes exhibiting G×E and trans regulation, indicating that expression G×E and heterosis may result from the evolution of transcription factors or their binding sites. P. hallii serves as the genomic model for its close relative and emerging biofuel crop, switchgrass (Panicum virgatum). Accordingly, the results here not only aid in the discovery of the genetic mechanisms that underlie local adaptation but also provide a foundation to improve switchgrass yield under water-limited conditions. PMID:26953271

Hepatic expression of spermatogenic genes and their transiently remarkable downregulations in Wistar-Kyoto rats in response to lead-nitrate administration: strain-difference in the gene expression patterns.

PubMed

Nemoto, Kiyomitsu; Ito, Sei; Yoshida, Chiaki; Miyata, Misaki; Kojima, Misaki; Degawa, Masakuni

2011-06-01

Administration of lead ion (Pb) to rats and mice affects hepatic functions such as the induction of hepatic cell proliferation and upregulation of cholesterol biosynthesis. To identify the genes for which expression changes in response to Pb-administration, we analyzed hepatic gene expression patterns in stroke-prone spontaneously hypertensive rat (SHRSP), its normotensive control, Wistar-Kyoto rat (WKY), and Spraque-Dawley (SD) rat strains, 3, 6, and 12 hr later after single i.v. injection of lead nitrate (LN) at a dose of 100 µmol using a DNA microarray technique. The data analysis demonstrated that the expression of a great number of genes was transiently and remarkably downregulated 3 hr after LN-injection, and then recovered to control levels only in LN-injected WKY. These normal hepatic expression levels in WKY and SHRSP were much higher than those in SD rats. Furthermore, most of these genes were ones thought to be expressed specifically in the spermatids and/or testes; i.e. genes encoding protamin 1, transition protein 1, and transition protein 2. These findings suggest that the regulation system common to expression of all of these genes could be a target site of Pb-toxic action, at least, in the liver of WKY, and that this system might be similar to the system essential for spermatogenesis, especially spermiogenesis, in the testis. In addition, it appears that clarifying the cause of the difference between the systems of WKY and SHRSP might aid in identifying the pathologic genes in SHRSP. Finally, it will be an important to clarify how the products of the genes related to spermatogenesis, including spermiogenesis, are functional in the livers of WKY and SHRSP.

Oxytocin, vasopressin and estrogen receptor gene expression in relation to social recognition in female mice.

PubMed

Clipperton-Allen, Amy E; Lee, Anna W; Reyes, Anny; Devidze, Nino; Phan, Anna; Pfaff, Donald W; Choleris, Elena

2012-02-28

Inter- and intra-species differences in social behavior and recognition-related hormones and receptors suggest that different distribution and/or expression patterns may relate to social recognition. We used qRT-PCR to investigate naturally occurring differences in expression of estrogen receptor-alpha (ERα), ER-beta (ERβ), progesterone receptor (PR), oxytocin (OT) and receptor, and vasopressin (AVP) and receptors in proestrous female mice. Following four 5 min exposures to the same two conspecifics, one was replaced with a novel mouse in the final trial (T5). Gene expression was examined in mice showing high (85-100%) and low (40-60%) social recognition scores (i.e., preferential novel mouse investigation in T5) in eight socially-relevant brain regions. Results supported OT and AVP involvement in social recognition, and suggest that in the medial preoptic area, increased OT and AVP mRNA, together with ERα and ERβ gene activation, relate to improved social recognition. Initial social investigation correlated with ERs, PR and OTR in the dorsolateral septum, suggesting that these receptors may modulate social interest without affecting social recognition. Finally, increased lateral amygdala gene activation in the LR mice may be associated with general learning impairments, while decreased lateral amygdala activity may indicate more efficient cognitive mechanisms in the HR mice. Copyright © 2011 Elsevier Inc. All rights reserved.

Integration of Steady-State and Temporal Gene Expression Data for the Inference of Gene Regulatory Networks

PubMed Central

Wang, Yi Kan; Hurley, Daniel G.; Schnell, Santiago; Print, Cristin G.; Crampin, Edmund J.

2013-01-01

We develop a new regression algorithm, cMIKANA, for inference of gene regulatory networks from combinations of steady-state and time-series gene expression data. Using simulated gene expression datasets to assess the accuracy of reconstructing gene regulatory networks, we show that steady-state and time-series data sets can successfully be combined to identify gene regulatory interactions using the new algorithm. Inferring gene networks from combined data sets was found to be advantageous when using noisy measurements collected with either lower sampling rates or a limited number of experimental replicates. We illustrate our method by applying it to a microarray gene expression dataset from human umbilical vein endothelial cells (HUVECs) which combines time series data from treatment with growth factor TNF and steady state data from siRNA knockdown treatments. Our results suggest that the combination of steady-state and time-series datasets may provide better prediction of RNA-to-RNA interactions, and may also reveal biological features that cannot be identified from dynamic or steady state information alone. Finally, we consider the experimental design of genomics experiments for gene regulatory network inference and show that network inference can be improved by incorporating steady-state measurements with time-series data. PMID:23967277

Microarray gene expression profiling using core biopsies of renal neoplasia.

PubMed

Rogers, Craig G; Ditlev, Jonathon A; Tan, Min-Han; Sugimura, Jun; Qian, Chao-Nan; Cooper, Jeff; Lane, Brian; Jewett, Michael A; Kahnoski, Richard J; Kort, Eric J; Teh, Bin T

2009-01-01

We investigate the feasibility of using microarray gene expression profiling technology to analyze core biopsies of renal tumors for classification of tumor histology. Core biopsies were obtained ex-vivo from 7 renal tumors-comprised of four histological subtypes-following radical nephrectomy using 18-gauge biopsy needles. RNA was isolated from these samples and, in the case of biopsy samples, amplified by in vitro transcription. Microarray analysis was then used to quantify the mRNA expression patterns in these samples relative to non-diseased renal tissue mRNA. Genes with significant variation across all non-biopsy tumor samples were identified, and the relationship between tumor and biopsy samples in terms of expression levels of these genes was then quantified in terms of Euclidean distance, and visualized by complete linkage clustering. Final pathologic assessment of kidney tumors demonstrated clear cell renal cell carcinoma (4), oncocytoma (1), angiomyolipoma (1) and adrenalcortical carcinoma (1). Five of the seven biopsy samples were most similar in terms of gene expression to the resected tumors from which they were derived in terms of Euclidean distance. All seven biopsies were assigned to the correct histological class by hierarchical clustering. We demonstrate the feasibility of gene expression profiling of core biopsies of renal tumors to classify tumor histology.

Microarray gene expression profiling using core biopsies of renal neoplasia

PubMed Central

Rogers, Craig G.; Ditlev, Jonathon A.; Tan, Min-Han; Sugimura, Jun; Qian, Chao-Nan; Cooper, Jeff; Lane, Brian; Jewett, Michael A.; Kahnoski, Richard J.; Kort, Eric J.; Teh, Bin T.

2009-01-01

We investigate the feasibility of using microarray gene expression profiling technology to analyze core biopsies of renal tumors for classification of tumor histology. Core biopsies were obtained ex-vivo from 7 renal tumors—comprised of four histological subtypes—following radical nephrectomy using 18-gauge biopsy needles. RNA was isolated from these samples and, in the case of biopsy samples, amplified by in vitro transcription. Microarray analysis was then used to quantify the mRNA expression patterns in these samples relative to non-diseased renal tissue mRNA. Genes with significant variation across all non-biopsy tumor samples were identified, and the relationship between tumor and biopsy samples in terms of expression levels of these genes was then quantified in terms of Euclidean distance, and visualized by complete linkage clustering. Final pathologic assessment of kidney tumors demonstrated clear cell renal cell carcinoma (4), oncocytoma (1), angiomyolipoma (1) and adrenalcortical carcinoma (1). Five of the seven biopsy samples were most similar in terms of gene expression to the resected tumors from which they were derived in terms of Euclidean distance. All seven biopsies were assigned to the correct histological class by hierarchical clustering. We demonstrate the feasibility of gene expression profiling of core biopsies of renal tumors to classify tumor histology. PMID:19966938

Correlated mRNAs and miRNAs from co-expression and regulatory networks affect porcine muscle and finally meat properties.

PubMed

Ponsuksili, Siriluck; Du, Yang; Hadlich, Frieder; Siengdee, Puntita; Murani, Eduard; Schwerin, Manfred; Wimmers, Klaus

2013-08-05

Physiological processes aiding the conversion of muscle to meat involve many genes associated with muscle structure and metabolic processes. MicroRNAs regulate networks of genes to orchestrate cellular functions, in turn regulating phenotypes. We applied weighted gene co-expression network analysis to identify co-expression modules that correlated to meat quality phenotypes and were highly enriched for genes involved in glucose metabolism, response to wounding, mitochondrial ribosome, mitochondrion, and extracellular matrix. Negative correlation of miRNA with mRNA and target prediction were used to select transcripts out of the modules of trait-associated mRNAs to further identify those genes that are correlated with post mortem traits. Porcine muscle co-expression transcript networks that correlated to post mortem traits were identified. The integration of miRNA and mRNA expression analyses, as well as network analysis, enabled us to interpret the differentially-regulated genes from a systems perspective. Linking co-expression networks of transcripts and hierarchically organized pairs of miRNAs and mRNAs to meat properties yields new insight into several biological pathways underlying phenotype differences. These pathways may also be diagnostic for many myopathies, which are accompanied by deficient nutrient and oxygen supply of muscle fibers.

Mindfulness-Based Stress Reduction training reduces loneliness and pro-inflammatory gene expression in older adults: a small randomized controlled trial.

PubMed

Creswell, J David; Irwin, Michael R; Burklund, Lisa J; Lieberman, Matthew D; Arevalo, Jesusa M G; Ma, Jeffrey; Breen, Elizabeth Crabb; Cole, Steven W

2012-10-01

Lonely older adults have increased expression of pro-inflammatory genes as well as increased risk for morbidity and mortality. Previous behavioral treatments have attempted to reduce loneliness and its concomitant health risks, but have had limited success. The present study tested whether the 8-week Mindfulness-Based Stress Reduction (MBSR) program (compared to a Wait-List control group) reduces loneliness and downregulates loneliness-related pro-inflammatory gene expression in older adults (N = 40). Consistent with study predictions, mixed effect linear models indicated that the MBSR program reduced loneliness, compared to small increases in loneliness in the control group (treatment condition × time interaction: F(1,35) = 7.86, p = .008). Moreover, at baseline, there was an association between reported loneliness and upregulated pro-inflammatory NF-κB-related gene expression in circulating leukocytes, and MBSR downregulated this NF-κB-associated gene expression profile at post-treatment. Finally, there was a trend for MBSR to reduce C Reactive Protein (treatment condition × time interaction: (F(1,33) = 3.39, p = .075). This work provides an initial indication that MBSR may be a novel treatment approach for reducing loneliness and related pro-inflammatory gene expression in older adults. Copyright © 2012 Elsevier Inc. All rights reserved.

Mindfulness-Based Stress Reduction Training Reduces Loneliness and Pro-Inflammatory Gene Expression in Older Adults: A Small Randomized Controlled Trial

PubMed Central

Creswell, J. David; Irwin, Michael R.; Burklund, Lisa J.; Lieberman, Matthew D.; Arevalo, Jesusa M. G.; Ma, Jeffrey; Breen, Elizabeth Crabb; Cole, Steven W.

2013-01-01

Lonely older adults have increased expression of pro-inflammatory genes as well as increased risk for morbidity and mortality. Previous behavioral treatments have attempted to reduce loneliness and its concomitant health risks, but have had limited success. The present study tested whether the 8-week Mindfulness-Based Stress Reduction (MBSR) program (compared to a Wait-List control group) reduces loneliness and downregulates loneliness-related pro-inflammatory gene expression in older adults (N=40). Consistent with study predictions, mixed effect linear models indicated that the MBSR program reduced loneliness, compared to small increases in loneliness in the control group (treatment condition × time interaction: F(1,35)=7.86, p=.008). Moreover, at baseline, there was an association between reported loneliness and upregulated pro-inflammatory NF-κB-related gene expression in circulating leukocytes, and MBSR downregulated this NF-κB-associated gene expression profile at post-treatment. Finally, there was a trend for MBSR to reduce C Reactive Protein (treatment condition × time interaction: (F(1,33)=3.39, p=.075). This work provides an initial indication that MBSR may be a novel treatment approach for reducing loneliness and related pro-inflammatory gene expression in older adults. PMID:22820409

Interaction of rearing environment and reproductive tactic on gene expression profiles in Atlantic salmon

USGS Publications Warehouse

Aubin-Horth, N.; Letcher, B.H.; Hofmann, H.A.

2005-01-01

Organisms that share the same genotype can develop into divergent phenotypes, depending on environmental conditions. In Atlantic salmon, young males of the same age can be found either as sneakers or immature males that are future anadromous fish. Just as the organism-level phenotype varies between divergent male developmental trajectories, brain gene expression is expected to vary as well. We hypothesized that rearing environment can also have an important effect on gene expression in the brain and possibly interact with the reproductive tactic adopted. We tested this hypothesis by comparing brain gene expression profiles of the two male tactics in fish from the same population that were reared in either a natural stream or under laboratory conditions. We found that expression of certain genes was affected by rearing environment only, while others varied between male reproductive tactics independent of rearing environment. Finally, more than half of all genes that showed variable expression varied between the two male tactics only in one environment. Thus, in these fish, very different molecular pathways can give rise to similar macro-phenotypes depending on rearing environment. This result gives important insights into the molecular underpinnings of developmental plasticity in relationship to the environment. ?? 2005 The American Genetic Association.

Analysis of the SWI/SNF chromatin-remodeling complex during early heart development and BAF250a repression cardiac gene transcription during P19 cell differentiation

PubMed Central

Singh, Ajeet Pratap; Archer, Trevor K.

2014-01-01

The regulatory networks of differentiation programs and the molecular mechanisms of lineage-specific gene regulation in mammalian embryos remain only partially defined. We document differential expression and temporal switching of BRG1-associated factor (BAF) subunits, core pluripotency factors and cardiac-specific genes during post-implantation development and subsequent early organogenesis. Using affinity purification of BRG1 ATPase coupled to mass spectrometry, we characterized the cardiac-enriched remodeling complexes present in E8.5 mouse embryos. The relative abundance and combinatorial assembly of the BAF subunits provides functional specificity to Switch/Sucrose NonFermentable (SWI/SNF) complexes resulting in a unique gene expression profile in the developing heart. Remarkably, the specific depletion of the BAF250a subunit demonstrated differential effects on cardiac-specific gene expression and resulted in arrhythmic contracting cardiomyocytes in vitro. Indeed, the BAF250a physically interacts and functionally cooperates with Nucleosome Remodeling and Histone Deacetylase (NURD) complex subunits to repressively regulate chromatin structure of the cardiac genes by switching open and poised chromatin marks associated with active and repressed gene expression. Finally, BAF250a expression modulates BRG1 occupancy at the loci of cardiac genes regulatory regions in P19 cell differentiation. These findings reveal specialized and novel cardiac-enriched SWI/SNF chromatin-remodeling complexes, which are required for heart formation and critical for cardiac gene expression regulation at the early stages of heart development. PMID:24335282

Silencing is noisy: population and cell level noise in telomere-adjacent genes is dependent on telomere position and sir2.

PubMed

Anderson, Matthew Z; Gerstein, Aleeza C; Wigen, Lauren; Baller, Joshua A; Berman, Judith

2014-07-01

Cell-to-cell gene expression noise is thought to be an important mechanism for generating phenotypic diversity. Furthermore, telomeric regions are major sites for gene amplification, which is thought to drive genetic diversity. Here we found that individual subtelomeric TLO genes exhibit increased variation in transcript and protein levels at both the cell-to-cell level as well as at the population-level. The cell-to-cell variation, termed Telomere-Adjacent Gene Expression Noise (TAGEN) was largely intrinsic noise and was dependent upon genome position: noise was reduced when a TLO gene was expressed at an ectopic internal locus and noise was elevated when a non-telomeric gene was expressed at a telomere-adjacent locus. This position-dependent TAGEN also was dependent on Sir2p, an NAD+-dependent histone deacetylase. Finally, we found that telomere silencing and TAGEN are tightly linked and regulated in cis: selection for either silencing or activation of a TLO-adjacent URA3 gene resulted in reduced noise at the neighboring TLO but not at other TLO genes. This provides experimental support to computational predictions that the ability to shift between silent and active chromatin states has a major effect on cell-to-cell noise. Furthermore, it demonstrates that these shifts affect the degree of expression variation at each telomere individually.

Integrated network analysis identifies fight-club nodes as a class of hubs encompassing key putative switch genes that induce major transcriptome reprogramming during grapevine development.

PubMed

Palumbo, Maria Concetta; Zenoni, Sara; Fasoli, Marianna; Massonnet, Mélanie; Farina, Lorenzo; Castiglione, Filippo; Pezzotti, Mario; Paci, Paola

2014-12-01

We developed an approach that integrates different network-based methods to analyze the correlation network arising from large-scale gene expression data. By studying grapevine (Vitis vinifera) and tomato (Solanum lycopersicum) gene expression atlases and a grapevine berry transcriptomic data set during the transition from immature to mature growth, we identified a category named "fight-club hubs" characterized by a marked negative correlation with the expression profiles of neighboring genes in the network. A special subset named "switch genes" was identified, with the additional property of many significant negative correlations outside their own group in the network. Switch genes are involved in multiple processes and include transcription factors that may be considered master regulators of the previously reported transcriptome remodeling that marks the developmental shift from immature to mature growth. All switch genes, expressed at low levels in vegetative/green tissues, showed a significant increase in mature/woody organs, suggesting a potential regulatory role during the developmental transition. Finally, our analysis of tomato gene expression data sets showed that wild-type switch genes are downregulated in ripening-deficient mutants. The identification of known master regulators of tomato fruit maturation suggests our method is suitable for the detection of key regulators of organ development in different fleshy fruit crops. © 2014 American Society of Plant Biologists. All rights reserved.

The Epstein–Barr virus nuclear protein SM is both a post-transcriptional inhibitor and activator of gene expression

PubMed Central

Ruvolo, Vivian; Wang, Eryu; Boyle, Sarah; Swaminathan, Sankar

1998-01-01

The Epstein–Barr virus (EBV) nuclear protein BS-MLF1 (SM) is expressed early after entry of EBV into the lytic cycle. SM transactivates reporter gene constructs driven by a wide variety of promoters, but the mechanism of SM action is poorly understood. In this study, we demonstrate that the SM protein inhibits expression of intron-containing genes and activates expression of intron-less genes. We demonstrate that SM has the predicted inhibitory effect on expression of a spliced EBV gene but activates an unspliced early EBV gene. SM inhibited gene expression at the post-transcriptional level by preventing the accumulation of nuclear and cytoplasmic RNA transcripts. Conversely, SM led to increased accumulation of nuclear mRNA from intron-less genes without affecting the rate of transcription, indicating that SM enhances nuclear RNA stability. The ratio of cytoplasmic to nuclear polyadenylated mRNA was increased in the presence of SM, suggesting that SM also enhances nucleo-cytoplasmic mRNA transport. The degree of transactivation by SM was dependent on the sequence of the 3′-untranslated region of the target mRNA. Finally, we demonstrate that the amino-terminal portion of SM fused to glutathione-S-transferase binds radioactively labeled RNA in vitro, indicating that SM is a single-stranded RNA binding protein. Importantly, the latent and immediate-early genes of EBV contain introns whereas many early and late genes do not. Thus, SM may down-regulate synthesis of host cell proteins and latent EBV proteins while simultaneously enhancing expression of specific lytic EBV genes by binding to mRNA and modulating its stability and transport. PMID:9671768

The Epstein-Barr virus nuclear protein SM is both a post-transcriptional inhibitor and activator of gene expression.

PubMed

Ruvolo, V; Wang, E; Boyle, S; Swaminathan, S

1998-07-21

The Epstein-Barr virus (EBV) nuclear protein BS-MLF1 (SM) is expressed early after entry of EBV into the lytic cycle. SM transactivates reporter gene constructs driven by a wide variety of promoters, but the mechanism of SM action is poorly understood. In this study, we demonstrate that the SM protein inhibits expression of intron-containing genes and activates expression of intron-less genes. We demonstrate that SM has the predicted inhibitory effect on expression of a spliced EBV gene but activates an unspliced early EBV gene. SM inhibited gene expression at the post-transcriptional level by preventing the accumulation of nuclear and cytoplasmic RNA transcripts. Conversely, SM led to increased accumulation of nuclear mRNA from intron-less genes without affecting the rate of transcription, indicating that SM enhances nuclear RNA stability. The ratio of cytoplasmic to nuclear polyadenylated mRNA was increased in the presence of SM, suggesting that SM also enhances nucleo-cytoplasmic mRNA transport. The degree of transactivation by SM was dependent on the sequence of the 3'-untranslated region of the target mRNA. Finally, we demonstrate that the amino-terminal portion of SM fused to glutathione-S-transferase binds radioactively labeled RNA in vitro, indicating that SM is a single-stranded RNA binding protein. Importantly, the latent and immediate-early genes of EBV contain introns whereas many early and late genes do not. Thus, SM may down-regulate synthesis of host cell proteins and latent EBV proteins while simultaneously enhancing expression of specific lytic EBV genes by binding to mRNA and modulating its stability and transport.

Integrated Quantitative Transcriptome Maps of Human Trisomy 21 Tissues and Cells

PubMed Central

Pelleri, Maria Chiara; Cattani, Chiara; Vitale, Lorenza; Antonaros, Francesca; Strippoli, Pierluigi; Locatelli, Chiara; Cocchi, Guido; Piovesan, Allison; Caracausi, Maria

2018-01-01

Down syndrome (DS) is due to the presence of an extra full or partial chromosome 21 (Hsa21). The identification of genes contributing to DS pathogenesis could be the key to any rational therapy of the associated intellectual disability. We aim at generating quantitative transcriptome maps in DS integrating all gene expression profile datasets available for any cell type or tissue, to obtain a complete model of the transcriptome in terms of both expression values for each gene and segmental trend of gene expression along each chromosome. We used the TRAM (Transcriptome Mapper) software for this meta-analysis, comparing transcript expression levels and profiles between DS and normal brain, lymphoblastoid cell lines, blood cells, fibroblasts, thymus and induced pluripotent stem cells, respectively. TRAM combined, normalized, and integrated datasets from different sources and across diverse experimental platforms. The main output was a linear expression value that may be used as a reference for each of up to 37,181 mapped transcripts analyzed, related to both known genes and expression sequence tag (EST) clusters. An independent example in vitro validation of fibroblast transcriptome map data was performed through “Real-Time” reverse transcription polymerase chain reaction showing an excellent correlation coefficient (r = 0.93, p < 0.0001) with data obtained in silico. The availability of linear expression values for each gene allowed the testing of the gene dosage hypothesis of the expected 3:2 DS/normal ratio for Hsa21 as well as other human genes in DS, in addition to listing genes differentially expressed with statistical significance. Although a fraction of Hsa21 genes escapes dosage effects, Hsa21 genes are selectively over-expressed in DS samples compared to genes from other chromosomes, reflecting a decisive role in the pathogenesis of the syndrome. Finally, the analysis of chromosomal segments reveals a high prevalence of Hsa21 over-expressed segments over the other genomic regions, suggesting, in particular, a specific region on Hsa21 that appears to be frequently over-expressed (21q22). Our complete datasets are released as a new framework to investigate transcription in DS for individual genes as well as chromosomal segments in different cell types and tissues. PMID:29740474

Differential expression of genes and proteins associated with wool follicle cycling.

PubMed

Liu, Nan; Li, Hegang; Liu, Kaidong; Yu, Juanjuan; Cheng, Ming; De, Wei; Liu, Jifeng; Shi, Shuyan; He, Yanghua; Zhao, Jinshan

2014-08-01

Sheep are valuable resources for the wool industry. Wool growth of Aohan fine wool sheep has cycled during different seasons in 1 year. Therefore, identifying genes that control wool growth cycling might lead to ways for improving the quality and yield of fine wool. In this study, we employed Agilent sheep gene expression microarray and proteomic technology to compare the gene expression patterns of the body side skins at August and December time points in Aohan fine wool sheep (a Chinese indigenous breed). Microarray study revealed that 2,223 transcripts were differentially expressed, including 1,162 up-regulated and 1,061 down-regulated transcripts, comparing body side skin at the August time point to the December one (A/D) in Aohan fine wool sheep. Then seven differentially expressed genes were selected to validated the reliability of the gene chip data. The majority of the genes possibly related to follicle development and wool growth could be assigned into the categories including regulation of receptor binding, extracellular region, protein binding and extracellular space. Proteomic study revealed that 84 protein spots showed significant differences in expression levels. Of the 84, 63 protein spots were upregulated and 21 were downregulated in A/D. Finally, 55 protein points were determined through MALDI-TOF/MS analyses. Furthermore, the regulation mechanism of hair follicle might resemble that of fetation.

Developmental regulation of diacylglycerol acyltransferase family gene expression in tung tree tissues

USDA-ARS?s Scientific Manuscript database

Diacylglycerol acyltransferases (DGAT) are responsible for the final and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. DGAT genes have been identified in numerous organisms. Multiple isoforms of DGAT are present in eukaryotes, including DGAT1 and DGAT2 of tung tre...

Diversity in the carotenoid profiles and the expression of genes related to carotenoid accumulation among citrus genotypes

PubMed Central

Ikoma, Yoshinori; Matsumoto, Hikaru; Kato, Masaya

2016-01-01

Carotenoids are not only important to the plants themselves but also are beneficial to human health. Since citrus fruit is a good source of carotenoids for the human diet, it is important to study carotenoid profiles and the accumulation mechanism in citrus fruit. Thus, in the present paper, we describe the diversity in the carotenoid profiles of fruit among citrus genotypes. In regard to carotenoids, such as β-cryptoxanthin, violaxanthin, lycopene, and β-citraurin, the relationship between the carotenoid profile and the expression of carotenoid-biosynthetic genes is discussed. Finally, recent results of quantitative trait locus (QTL) analyses of carotenoid contents and expression levels of carotenoid-biosynthetic genes in citrus fruit are shown. PMID:27069398

Effect of MLH1 -93G>A on gene expression in patients with colorectal cancer.

PubMed

Funck, Alexandre; Santos, Juliana C; Silva-Fernandes, Isabelle J L; Rabenhorst, Silvia H B; Martinez, Carlos A R; Ribeiro, Marcelo L

2014-09-01

The DNA repair machinery plays a key role in maintaining genomic stability by preventing the emergence of mutations. Furthermore, the -93G>A polymorphism in the MLH1 gene has been associated with an increased risk of developing colorectal cancer. Therefore, the aim of this study was to examine the expression pattern and effect of this polymorphism in normal and tumour samples from patients with colorectal cancer. The MLH1 -93G>A (rs1800734) polymorphism was detected by PCR-RFLP in 49 cases of colorectal cancer. MLH1 expression was investigated using real-time quantitative PCR. The results indicate a significant decrease in MLH1 expression in tumour samples compared to their normal counterparts. The MLH1 gene was also significantly repressed in samples from patients who had some degree of tumour invasion into other organs. Similarly, those patients who were in a more advanced tumour stage (TNM III and IV) exhibited a significant reduction in MLH1 gene expression. Finally, the mutant genotype AA of MLH1 was associated with a significant decrease in the expression of this gene. This finding suggests that this polymorphism could increase the risk of developing colorectal cancer by a defective mismatch repair system, particularly through the loss of MLH1 expression in an allele-specific manner.

Non-parent of Origin Expression of Numerous Effector Genes Indicates a Role of Gene Regulation in Host Adaption of the Hybrid Triticale Powdery Mildew Pathogen

PubMed Central

Praz, Coraline R.; Menardo, Fabrizio; Robinson, Mark D.; Müller, Marion C.; Wicker, Thomas; Bourras, Salim; Keller, Beat

2018-01-01

Powdery mildew is an important disease of cereals. It is caused by one species, Blumeria graminis, which is divided into formae speciales each of which is highly specialized to one host. Recently, a new form capable of growing on triticale (B.g. triticale) has emerged through hybridization between wheat and rye mildews (B.g. tritici and B.g. secalis, respectively). In this work, we used RNA sequencing to study the molecular basis of host adaptation in B.g. triticale. We analyzed gene expression in three B.g. tritici isolates, two B.g. secalis isolates and two B.g. triticale isolates and identified a core set of putative effector genes that are highly expressed in all formae speciales. We also found that the genes differentially expressed between isolates of the same form as well as between different formae speciales were enriched in putative effectors. Their coding genes belong to several families including some which contain known members of mildew avirulence (Avr) and suppressor (Svr) genes. Based on these findings we propose that effectors play an important role in host adaptation that is mechanistically based on Avr-Resistance gene-Svr interactions. We also found that gene expression in the B.g. triticale hybrid is mostly conserved with the parent-of-origin, but some genes inherited from B.g. tritici showed a B.g. secalis-like expression. Finally, we identified 11 unambiguous cases of putative effector genes with hybrid-specific, non-parent of origin gene expression, and we propose that they are possible determinants of host specialization in triticale mildew. These data suggest that altered expression of multiple effector genes, in particular Avr and Svr related factors, might play a role in mildew host adaptation based on hybridization. PMID:29441081

A method to identify differential expression profiles of time-course gene data with Fourier transformation

PubMed Central

2013-01-01

Background Time course gene expression experiments are an increasingly popular method for exploring biological processes. Temporal gene expression profiles provide an important characterization of gene function, as biological systems are both developmental and dynamic. With such data it is possible to study gene expression changes over time and thereby to detect differential genes. Much of the early work on analyzing time series expression data relied on methods developed originally for static data and thus there is a need for improved methodology. Since time series expression is a temporal process, its unique features such as autocorrelation between successive points should be incorporated into the analysis. Results This work aims to identify genes that show different gene expression profiles across time. We propose a statistical procedure to discover gene groups with similar profiles using a nonparametric representation that accounts for the autocorrelation in the data. In particular, we first represent each profile in terms of a Fourier basis, and then we screen out genes that are not differentially expressed based on the Fourier coefficients. Finally, we cluster the remaining gene profiles using a model-based approach in the Fourier domain. We evaluate the screening results in terms of sensitivity, specificity, FDR and FNR, compare with the Gaussian process regression screening in a simulation study and illustrate the results by application to yeast cell-cycle microarray expression data with alpha-factor synchronization. The key elements of the proposed methodology: (i) representation of gene profiles in the Fourier domain; (ii) automatic screening of genes based on the Fourier coefficients and taking into account autocorrelation in the data, while controlling the false discovery rate (FDR); (iii) model-based clustering of the remaining gene profiles. Conclusions Using this method, we identified a set of cell-cycle-regulated time-course yeast genes. The proposed method is general and can be potentially used to identify genes which have the same patterns or biological processes, and help facing the present and forthcoming challenges of data analysis in functional genomics. PMID:24134721

Genome-wide identification and characterization of auxin response factor (ARF) family genes related to flower and fruit development in papaya (Carica papaya L.).

PubMed

Liu, Kaidong; Yuan, Changchun; Li, Haili; Lin, Wanhuang; Yang, Yanjun; Shen, Chenjia; Zheng, Xiaolin

2015-11-05

Auxin and auxin signaling are involved in a series of developmental processes in plants. Auxin Response Factors (ARFs) is reported to modulate the expression of target genes by binding to auxin response elements (AuxREs) and influence the transcriptional activation of down-stream target genes. However, how ARF genes function in flower development and fruit ripening of papaya (Carica papaya L.) is largely unknown. In this study, a comprehensive characterization and expression profiling analysis of 11 C. papaya ARF (CpARF) genes was performed using the newly updated papaya reference genome data. We analyzed CpARF expression patterns at different developmental stages. CpARF1, CpARF2, CpARF4, CpARF5, and CpARF10 showed the highest expression at the initial stage of flower development, but decreased during the following developmental stages. CpARF6 expression increased during the developmental process and reached its peak level at the final stage of flower development. The expression of CpARF1 increased significantly during the fruit ripening stages. Many AuxREs were included in the promoters of two ethylene signaling genes (CpETR1 and CpETR2) and three ethylene-synthesis-related genes (CpACS1, CpACS2, and CpACO1), suggesting that CpARFs might be involved in fruit ripening via the regulation of ethylene signaling. Our study provided comprehensive information on ARF family in papaya, including gene structures, chromosome locations, phylogenetic relationships, and expression patterns. The involvement of CpARF gene expression changes in flower and fruit development allowed us to understand the role of ARF-mediated auxin signaling in the maturation of reproductive organs in papaya.

Involvement of adenosine monophosphate-activated protein kinase in the influence of timed high-fat evening diet on the hepatic clock and lipogenic gene expression in mice.

PubMed

Huang, Yan; Zhu, Zengyan; Xie, Meilin; Xue, Jie

2015-09-01

A high-fat diet may result in changes in hepatic clock gene expression, but potential mechanisms are not yet elucidated. Adenosine monophosphate-activated protein kinase (AMPK) is a serine/threonine protein kinase that is recognized as a key regulator of energy metabolism and certain clock genes. Therefore, we hypothesized that AMPK may be involved in the alteration of hepatic clock gene expression under a high-fat environment. This study aimed to examine the effects of timed high-fat evening diet on the activity of hepatic AMPK, clock genes, and lipogenic genes. Mice with hyperlipidemic fatty livers were induced by orally administering high-fat milk via gavage every evening (19:00-20:00) for 6 weeks. Results showed that timed high-fat diet in the evening not only decreased the hepatic AMPK protein expression and activity but also disturbed its circadian rhythm. Accordingly, the hepatic clock genes, including clock, brain-muscle-Arnt-like 1, cryptochrome 2, and period 2, exhibited prominent changes in their expression rhythms and/or amplitudes. The diurnal rhythms of the messenger RNA expression of peroxisome proliferator-activated receptorα, acetyl-CoA carboxylase 1α, and carnitine palmitoyltransferase 1 were also disrupted; the amplitude of peroxisome proliferator-activated receptorγcoactivator 1α was significantly decreased at 3 time points, and fatty liver was observed. These findings demonstrate that timed high-fat diet at night can change hepatic AMPK protein levels, activity, and circadian rhythm, which may subsequently alter the circadian expression of several hepatic clock genes and finally result in the disorder of hepatic lipogenic gene expression and the formation of fatty liver. Copyright © 2015 Elsevier Inc. All rights reserved.

Generation of Envelope-Modified Baculoviruses for Gene Delivery into Mammalian Cells.

PubMed

Hofmann, Christian

2016-01-01

Genetically modified baculoviruses can efficiently deliver and express genes in mammalian cells. The major prerequisite for the expression of a gene transferred by baculovirus is its control by a promoter that is active in mammalian cells. This chapter describes methods for producing second generation baculovirus vectors through modification of their envelope. Envelope modified baculoviruses offer additional new applications of the system, such as their use in in vivo gene delivery, targeting, and vaccination. Methods of generating a recombinant baculovirus vector with a modified envelope and its amplification and purification, including technical scale production, are discussed. A variety of notes give clues regarding specific technical procedures. Finally, methods to analyze the virus and transduction procedures are presented.

Simple Shared Motifs (SSM) in conserved region of promoters: a new approach to identify co-regulation patterns.

PubMed

Gruel, Jérémy; LeBorgne, Michel; LeMeur, Nolwenn; Théret, Nathalie

2011-09-12

Regulation of gene expression plays a pivotal role in cellular functions. However, understanding the dynamics of transcription remains a challenging task. A host of computational approaches have been developed to identify regulatory motifs, mainly based on the recognition of DNA sequences for transcription factor binding sites. Recent integration of additional data from genomic analyses or phylogenetic footprinting has significantly improved these methods. Here, we propose a different approach based on the compilation of Simple Shared Motifs (SSM), groups of sequences defined by their length and similarity and present in conserved sequences of gene promoters. We developed an original algorithm to search and count SSM in pairs of genes. An exceptional number of SSM is considered as a common regulatory pattern. The SSM approach is applied to a sample set of genes and validated using functional gene-set enrichment analyses. We demonstrate that the SSM approach selects genes that are over-represented in specific biological categories (Ontology and Pathways) and are enriched in co-expressed genes. Finally we show that genes co-expressed in the same tissue or involved in the same biological pathway have increased SSM values. Using unbiased clustering of genes, Simple Shared Motifs analysis constitutes an original contribution to provide a clearer definition of expression networks.

Simple Shared Motifs (SSM) in conserved region of promoters: a new approach to identify co-regulation patterns

PubMed Central

2011-01-01

Background Regulation of gene expression plays a pivotal role in cellular functions. However, understanding the dynamics of transcription remains a challenging task. A host of computational approaches have been developed to identify regulatory motifs, mainly based on the recognition of DNA sequences for transcription factor binding sites. Recent integration of additional data from genomic analyses or phylogenetic footprinting has significantly improved these methods. Results Here, we propose a different approach based on the compilation of Simple Shared Motifs (SSM), groups of sequences defined by their length and similarity and present in conserved sequences of gene promoters. We developed an original algorithm to search and count SSM in pairs of genes. An exceptional number of SSM is considered as a common regulatory pattern. The SSM approach is applied to a sample set of genes and validated using functional gene-set enrichment analyses. We demonstrate that the SSM approach selects genes that are over-represented in specific biological categories (Ontology and Pathways) and are enriched in co-expressed genes. Finally we show that genes co-expressed in the same tissue or involved in the same biological pathway have increased SSM values. Conclusions Using unbiased clustering of genes, Simple Shared Motifs analysis constitutes an original contribution to provide a clearer definition of expression networks. PMID:21910886

Different waves of effector genes with contrasted genomic location are expressed by Leptosphaeria maculans during cotyledon and stem colonization of oilseed rape.

PubMed

Gervais, Julie; Plissonneau, Clémence; Linglin, Juliette; Meyer, Michel; Labadie, Karine; Cruaud, Corinne; Fudal, Isabelle; Rouxel, Thierry; Balesdent, Marie-Hélène

2017-10-01

Leptosphaeria maculans, the causal agent of stem canker disease, colonizes oilseed rape (Brassica napus) in two stages: a short and early colonization stage corresponding to cotyledon or leaf colonization, and a late colonization stage during which the fungus colonizes systemically and symptomlessly the plant during several months before stem canker appears. To date, the determinants of the late colonization stage are poorly understood; L. maculans may either successfully escape plant defences, leading to stem canker development, or the plant may develop an 'adult-stage' resistance reducing canker incidence. To obtain an insight into these determinants, we performed an RNA-sequencing (RNA-seq) pilot project comparing fungal gene expression in infected cotyledons and in symptomless or necrotic stems. Despite the low fraction of fungal material in infected stems, sufficient fungal transcripts were detected and a large number of fungal genes were expressed, thus validating the feasibility of the approach. Our analysis showed that all avirulence genes previously identified are under-expressed during stem colonization compared with cotyledon colonization. A validation RNA-seq experiment was then performed to investigate the expression of candidate effector genes during systemic colonization. Three hundred and seven 'late' effector candidates, under-expressed in the early colonization stage and over-expressed in the infected stems, were identified. Finally, our analysis revealed a link between the regulation of expression of effectors and their genomic location: the 'late' effector candidates, putatively involved in systemic colonization, are located in gene-rich genomic regions, whereas the 'early' effector genes, over-expressed in the early colonization stage, are located in gene-poor regions of the genome. © 2016 BSPP AND JOHN WILEY & SONS LTD.

Selection of suitable reference genes for normalization of genes of interest in canine soft tissue sarcomas using quantitative real-time polymerase chain reaction.

PubMed

Zornhagen, K W; Kristensen, A T; Hansen, A E; Oxboel, J; Kjaer, A

2015-12-01

Quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR) is a sensitive technique for quantifying gene expression. Stably expressed reference genes are necessary for normalization of RT-qPCR data. Only a few articles have been published on reference genes in canine tumours. The objective of this study was to demonstrate how to identify suitable reference genes for normalization of genes of interest in canine soft tissue sarcomas using RT-qPCR. Primer pairs for 17 potential reference genes were designed and tested in archival tumour biopsies from six dogs. The geNorm algorithm was used to analyse the most suitable reference genes. Eight potential reference genes were excluded from this final analysis because of their dissociation curves. β-Glucuronidase (GUSB) and proteasome subunit, beta type, 6 (PSMB6) were most stably expressed with an M value of 0.154 and a CV of 0.053 describing their average stability. We suggest that choice of reference genes should be based on specific testing in every new experimental set-up. © 2014 John Wiley & Sons Ltd.

Pgas, a Low-pH-Induced Promoter, as a Tool for Dynamic Control of Gene Expression for Metabolic Engineering of Aspergillus niger

PubMed Central

Yin, Xian; Shin, Hyun-Dong; Li, Jianghua; Du, Guocheng; Chen, Jian

2017-01-01

ABSTRACT The dynamic control of gene expression is important for adjusting fluxes in order to obtain desired products and achieve appropriate cell growth, particularly when the synthesis of a desired product drains metabolites required for cell growth. For dynamic gene expression, a promoter responsive to a particular environmental stressor is vital. Here, we report a low-pH-inducible promoter, Pgas, which promotes minimal gene expression at pH values above 5.0 but functions efficiently at low pHs, such as pH 2.0. First, we performed a transcriptional analysis of Aspergillus niger, an excellent platform for the production of organic acids, and we found that the promoter Pgas may act efficiently at low pH. Then, a gene for synthetic green fluorescent protein (sGFP) was successfully expressed by Pgas at pH 2.0, verifying the results of the transcriptional analysis. Next, Pgas was used to express the cis-aconitate decarboxylase (cad) gene of Aspergillus terreus in A. niger, allowing the production of itaconic acid at a titer of 4.92 g/liter. Finally, we found that Pgas strength was independent of acid type and acid ion concentration, showing dependence on pH only. IMPORTANCE The promoter Pgas can be used for the dynamic control of gene expression in A. niger for metabolic engineering to produce organic acids. This promoter may also be a candidate tool for genetic engineering. PMID:28087530

Gene expression changes governing extreme dehydration tolerance in an Antarctic insect

PubMed Central

Teets, Nicholas M.; Peyton, Justin T.; Colinet, Herve; Renault, David; Kelley, Joanna L.; Kawarasaki, Yuta; Lee, Richard E.; Denlinger, David L.

2012-01-01

Among terrestrial organisms, arthropods are especially susceptible to dehydration, given their small body size and high surface area to volume ratio. This challenge is particularly acute for polar arthropods that face near-constant desiccating conditions, as water is frozen and thus unavailable for much of the year. The molecular mechanisms that govern extreme dehydration tolerance in insects remain largely undefined. In this study, we used RNA sequencing to quantify transcriptional mechanisms of extreme dehydration tolerance in the Antarctic midge, Belgica antarctica, the world’s southernmost insect and only insect endemic to Antarctica. Larvae of B. antarctica are remarkably tolerant of dehydration, surviving losses up to 70% of their body water. Gene expression changes in response to dehydration indicated up-regulation of cellular recycling pathways including the ubiquitin-mediated proteasome and autophagy, with concurrent down-regulation of genes involved in general metabolism and ATP production. Metabolomics results revealed shifts in metabolite pools that correlated closely with changes in gene expression, indicating that coordinated changes in gene expression and metabolism are a critical component of the dehydration response. Finally, using comparative genomics, we compared our gene expression results with a transcriptomic dataset for the Arctic collembolan, Megaphorura arctica. Although B. antarctica and M. arctica are adapted to similar environments, our analysis indicated very little overlap in expression profiles between these two arthropods. Whereas several orthologous genes showed similar expression patterns, transcriptional changes were largely species specific, indicating these polar arthropods have developed distinct transcriptional mechanisms to cope with similar desiccating conditions. PMID:23197828

Gene expression changes governing extreme dehydration tolerance in an Antarctic insect.

PubMed

Teets, Nicholas M; Peyton, Justin T; Colinet, Herve; Renault, David; Kelley, Joanna L; Kawarasaki, Yuta; Lee, Richard E; Denlinger, David L

2012-12-11

Among terrestrial organisms, arthropods are especially susceptible to dehydration, given their small body size and high surface area to volume ratio. This challenge is particularly acute for polar arthropods that face near-constant desiccating conditions, as water is frozen and thus unavailable for much of the year. The molecular mechanisms that govern extreme dehydration tolerance in insects remain largely undefined. In this study, we used RNA sequencing to quantify transcriptional mechanisms of extreme dehydration tolerance in the Antarctic midge, Belgica antarctica, the world's southernmost insect and only insect endemic to Antarctica. Larvae of B. antarctica are remarkably tolerant of dehydration, surviving losses up to 70% of their body water. Gene expression changes in response to dehydration indicated up-regulation of cellular recycling pathways including the ubiquitin-mediated proteasome and autophagy, with concurrent down-regulation of genes involved in general metabolism and ATP production. Metabolomics results revealed shifts in metabolite pools that correlated closely with changes in gene expression, indicating that coordinated changes in gene expression and metabolism are a critical component of the dehydration response. Finally, using comparative genomics, we compared our gene expression results with a transcriptomic dataset for the Arctic collembolan, Megaphorura arctica. Although B. antarctica and M. arctica are adapted to similar environments, our analysis indicated very little overlap in expression profiles between these two arthropods. Whereas several orthologous genes showed similar expression patterns, transcriptional changes were largely species specific, indicating these polar arthropods have developed distinct transcriptional mechanisms to cope with similar desiccating conditions.

Selection and Validation of Reference Genes for qRT-PCR Expression Analysis of Candidate Genes Involved in Olfactory Communication in the Butterfly Bicyclus anynana

PubMed Central

Arun, Alok; Baumlé, Véronique; Amelot, Gaël; Nieberding, Caroline M.

2015-01-01

Real-time quantitative reverse transcription PCR (qRT-PCR) is a technique widely used to quantify the transcriptional expression level of candidate genes. qRT-PCR requires the selection of one or several suitable reference genes, whose expression profiles remain stable across conditions, to normalize the qRT-PCR expression profiles of candidate genes. Although several butterfly species (Lepidoptera) have become important models in molecular evolutionary ecology, so far no study aimed at identifying reference genes for accurate data normalization for any butterfly is available. The African bush brown butterfly Bicyclus anynana has drawn considerable attention owing to its suitability as a model for evolutionary ecology, and we here provide a maiden extensive study to identify suitable reference gene in this species. We monitored the expression profile of twelve reference genes: eEF-1α, FK506, UBQL40, RpS8, RpS18, HSP, GAPDH, VATPase, ACT3, TBP, eIF2 and G6PD. We tested the stability of their expression profiles in three different tissues (wings, brains, antennae), two developmental stages (pupal and adult) and two sexes (male and female), all of which were subjected to two food treatments (food stress and control feeding ad libitum). The expression stability and ranking of twelve reference genes was assessed using two algorithm-based methods, NormFinder and geNorm. Both methods identified RpS8 as the best suitable reference gene for expression data normalization. We also showed that the use of two reference genes is sufficient to effectively normalize the qRT-PCR data under varying tissues and experimental conditions that we used in B. anynana. Finally, we tested the effect of choosing reference genes with different stability on the normalization of the transcript abundance of a candidate gene involved in olfactory communication in B. anynana, the Fatty Acyl Reductase 2, and we confirmed that using an unstable reference gene can drastically alter the expression profile of the target candidate genes. PMID:25793735

Selection and validation of reference genes for qRT-PCR expression analysis of candidate genes involved in olfactory communication in the butterfly Bicyclus anynana.

PubMed

Arun, Alok; Baumlé, Véronique; Amelot, Gaël; Nieberding, Caroline M

2015-01-01

Real-time quantitative reverse transcription PCR (qRT-PCR) is a technique widely used to quantify the transcriptional expression level of candidate genes. qRT-PCR requires the selection of one or several suitable reference genes, whose expression profiles remain stable across conditions, to normalize the qRT-PCR expression profiles of candidate genes. Although several butterfly species (Lepidoptera) have become important models in molecular evolutionary ecology, so far no study aimed at identifying reference genes for accurate data normalization for any butterfly is available. The African bush brown butterfly Bicyclus anynana has drawn considerable attention owing to its suitability as a model for evolutionary ecology, and we here provide a maiden extensive study to identify suitable reference gene in this species. We monitored the expression profile of twelve reference genes: eEF-1α, FK506, UBQL40, RpS8, RpS18, HSP, GAPDH, VATPase, ACT3, TBP, eIF2 and G6PD. We tested the stability of their expression profiles in three different tissues (wings, brains, antennae), two developmental stages (pupal and adult) and two sexes (male and female), all of which were subjected to two food treatments (food stress and control feeding ad libitum). The expression stability and ranking of twelve reference genes was assessed using two algorithm-based methods, NormFinder and geNorm. Both methods identified RpS8 as the best suitable reference gene for expression data normalization. We also showed that the use of two reference genes is sufficient to effectively normalize the qRT-PCR data under varying tissues and experimental conditions that we used in B. anynana. Finally, we tested the effect of choosing reference genes with different stability on the normalization of the transcript abundance of a candidate gene involved in olfactory communication in B. anynana, the Fatty Acyl Reductase 2, and we confirmed that using an unstable reference gene can drastically alter the expression profile of the target candidate genes.

IP-10, p53, and Foxp3 Expression in Hepatocytes of Chronic Hepatitis B Patients with Cirrhosis and Hepatocellular Carcinoma.

PubMed

Shahera, Umme; Munshi, Saifullah; Jahan, Munira; Nessa, Afzalun; Alam, Shahinul; Tabassum, Shahina

2016-01-01

Elucidating differences in gene expression may be useful in understanding the molecular pathogenesis and for developing specific markers for the outcome of hepatitis B virus (HBV) infection. In the present study, expressions of host gene interferon gamma-inducible protein (IP-10), p53, and Foxp3 were studied in hepatocytes of patients with chronic HBV infection to determine a possible link between selected host gene expression and the outcome of HBV infection. The study was conducted in 60 patients with chronic HBV infection and they were divided into four groups: HBV-positive cirrhosis (n = 15), HBV-negative cirrhosis (n = 15), HBV-positive hepatocellular carcinoma (HCC) (n = 15) and HBV-negative HCC (n = 15). Total messenger ribonucleic acid (mRNA) extraction was done followed by complementary deoxyribonucleic acid (cDNA) synthesis, and finally gene expression was performed using real-time polymerase chain reaction (PCR) technique. IP-10 and p53 gene expressions were lower in HBV-positive cirrhosis, and Foxp3 gene expression was upregulated in HBV-positive cirrhosis in comparison to HBV-negative cirrhosis. The expressions of all the three genes were upregulated among HBV-positive HCC in comparison to HBV-negative HCC. The expression of IP-10, p53, and Foxp3 genes was upregulated in HBV-positive HCC in comparison to HBV-positive cirrhosis. This study indicates that there are variations in the expression of the selected genes among cirrhosis and HCC patients with or without HBV. All the three selected genes were more or less upregulated in HBV-positive HCC patients, but only Foxp3 expression was upregulated in HBV-positive cirrhosis. These three particular genes may have a role in the molecular pathogenesis and clinical outcome of HBV-positive cirrhosis and HCC patients. These aspects need further evaluation by studies with larger numbers of cirrhosis and HCC patients. Shahera U, Munshi S, Jahan M, Nessa A, Alam S, Tabassum S. IP-10, p53, and Foxp3 Expression in Hepatocytes of Chronic Hepatitis B Patients with Cirrhosis and Hepatocellular Carcinoma. Euroasian J Hepato-Gastroenterol 2016;6(2):149-153.

Computing and Applying Atomic Regulons to Understand Gene Expression and Regulation

DOE PAGES

Faria, José P.; Davis, James J.; Edirisinghe, Janaka N.; ...

2016-11-24

Understanding gene function and regulation is essential for the interpretation, prediction, and ultimate design of cell responses to changes in the environment. A multitude of technologies, abstractions, and interpretive frameworks have emerged to answer the challenges presented by genome function and regulatory network inference. Here, we propose a new approach for producing biologically meaningful clusters of coexpressed genes, called Atomic Regulons (ARs), based on expression data, gene context, and functional relationships. We demonstrate this new approach by computing ARs for Escherichia coli, which we compare with the coexpressed gene clusters predicted by two prevalent existing methods: hierarchical clustering and k-meansmore » clustering. We test the consistency of ARs predicted by all methods against expected interactions predicted by the Context Likelihood of Relatedness (CLR) mutual information based method, finding that the ARs produced by our approach show better agreement with CLR interactions. We then apply our method to compute ARs for four other genomes: Shewanella oneidensis, Pseudomonas aeruginosa, Thermus thermophilus, and Staphylococcus aureus. We compare the AR clusters from all genomes to study the similarity of coexpression among a phylogenetically diverse set of species, identifying subsystems that show remarkable similarity over wide phylogenetic distances. We also study the sensitivity of our method for computing ARs to the expression data used in the computation, showing that our new approach requires less data than competing approaches to converge to a near final configuration of ARs. We go on to use our sensitivity analysis to identify the specific experiments that lead most rapidly to the final set of ARs for E. coli. As a result, this analysis produces insights into improving the design of gene expression experiments.« less

Computing and Applying Atomic Regulons to Understand Gene Expression and Regulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faria, José P.; Davis, James J.; Edirisinghe, Janaka N.

Understanding gene function and regulation is essential for the interpretation, prediction, and ultimate design of cell responses to changes in the environment. A multitude of technologies, abstractions, and interpretive frameworks have emerged to answer the challenges presented by genome function and regulatory network inference. Here, we propose a new approach for producing biologically meaningful clusters of coexpressed genes, called Atomic Regulons (ARs), based on expression data, gene context, and functional relationships. We demonstrate this new approach by computing ARs for Escherichia coli, which we compare with the coexpressed gene clusters predicted by two prevalent existing methods: hierarchical clustering and k-meansmore » clustering. We test the consistency of ARs predicted by all methods against expected interactions predicted by the Context Likelihood of Relatedness (CLR) mutual information based method, finding that the ARs produced by our approach show better agreement with CLR interactions. We then apply our method to compute ARs for four other genomes: Shewanella oneidensis, Pseudomonas aeruginosa, Thermus thermophilus, and Staphylococcus aureus. We compare the AR clusters from all genomes to study the similarity of coexpression among a phylogenetically diverse set of species, identifying subsystems that show remarkable similarity over wide phylogenetic distances. We also study the sensitivity of our method for computing ARs to the expression data used in the computation, showing that our new approach requires less data than competing approaches to converge to a near final configuration of ARs. We go on to use our sensitivity analysis to identify the specific experiments that lead most rapidly to the final set of ARs for E. coli. As a result, this analysis produces insights into improving the design of gene expression experiments.« less

Comparative analysis of gene expression profiles of OPN signaling pathway in four kinds of liver diseases.

PubMed

Wang, Gaiping; Chen, Shasha; Zhao, Congcong; Li, Xiaofang; Zhao, Weiming; Yang, Jing; Chang, Cuifang; Xu, Cunshuan

2016-09-01

To explore the relevance of OPN signalling pathway to the occurrence and development of nonalcoholic fatty liver disease (NAFLD), liver cirrhosis (LC), hepatic cancer (HC) and acute hepatic failure (AHF) at transcriptional level, Rat Genome 230 2.0 Array was used to detect expression profiles of OPN signalling pathway-related genes in four kinds of liver diseases. The results showed that 23, 33, 59 and 74 genes were significantly changed in the above four kinds of liver diseases, respectively. H-clustering analysis showed that the expression profiles of OPN signalling-related genes were notably different in four kinds of liver diseases. Subsequently, a total of above-mentioned 147 genes were categorized into four clusters by k-means according to the similarity of gene expression, and expression analysis systematic explorer (EASE) functional enrichment analysis revealed that OPN signalling pathway-related genes were involved in cell adhesion and migration, cell proliferation, apoptosis, stress and inflammatory reaction, etc. Finally, ingenuity pathway analysis (IPA) software was used to predict the functions of OPN signalling-related genes, and the results indicated that the activities of ROS production, cell adhesion and migration, cell proliferation were remarkably increased, while that of apoptosis, stress and inflammatory reaction were reduced in four kinds of liver diseases. In summary, the above physiological activities changed more obviously in LC, HC and AHF than in NAFLD.

Integrated Network Analysis Identifies Fight-Club Nodes as a Class of Hubs Encompassing Key Putative Switch Genes That Induce Major Transcriptome Reprogramming during Grapevine Development[W][OPEN

PubMed Central

Palumbo, Maria Concetta; Zenoni, Sara; Fasoli, Marianna; Massonnet, Mélanie; Farina, Lorenzo; Castiglione, Filippo; Pezzotti, Mario; Paci, Paola

2014-01-01

We developed an approach that integrates different network-based methods to analyze the correlation network arising from large-scale gene expression data. By studying grapevine (Vitis vinifera) and tomato (Solanum lycopersicum) gene expression atlases and a grapevine berry transcriptomic data set during the transition from immature to mature growth, we identified a category named “fight-club hubs” characterized by a marked negative correlation with the expression profiles of neighboring genes in the network. A special subset named “switch genes” was identified, with the additional property of many significant negative correlations outside their own group in the network. Switch genes are involved in multiple processes and include transcription factors that may be considered master regulators of the previously reported transcriptome remodeling that marks the developmental shift from immature to mature growth. All switch genes, expressed at low levels in vegetative/green tissues, showed a significant increase in mature/woody organs, suggesting a potential regulatory role during the developmental transition. Finally, our analysis of tomato gene expression data sets showed that wild-type switch genes are downregulated in ripening-deficient mutants. The identification of known master regulators of tomato fruit maturation suggests our method is suitable for the detection of key regulators of organ development in different fleshy fruit crops. PMID:25490918

Inactivation of DNA-Binding Response Regulator Sak189 Abrogates β-Antigen Expression and Affects Virulence of Streptococcus agalactiae

PubMed Central

Rozhdestvenskaya, Anastasia S.; Totolian, Artem A.; Dmitriev, Alexander V.

2010-01-01

Background Streptococcus agalactiae is able to colonize numerous tissues employing different mechanisms of gene regulation, particularly via two-component regulatory systems. These systems sense the environmental stimuli and regulate expression of the genes including virulence genes. Recently, the novel two-component regulatory system Sak188/Sak189 was identified. In S. agalactiae genome, it was adjacent to the bac gene encoding for β-antigen, an important virulence factor. Methodology/Principal Findings In this study, the sak188 and sak189 genes were inactivated, and the functional role of Sak188/Sak189 two-component system in regulation of the β-antigen expression was investigated. It was demonstrated that both transcription of bac gene and expression of encoded β-antigen were controlled by Sak189 response regulator, but not Sak188 histidine kinase. It was also found that the regulation occurred at transcriptional level. Finally, insertional inactivation of sak189 gene, but not sak188 gene, significantly affected virulent properties of S. agalactiae. Conclusions/Significance Sak189 response regulator is necessary for activation of bac gene transcription. It also controls the virulent properties of S. agalactiae. Given that the primary functional role of Sak188/Sak189 two-component systems is a control of bac gene transcription, this system can be annotated as BgrR/S (bac gene regulatory system). PMID:20419089

Evaluating intra- and inter-individual variation in the human placental transcriptome.

PubMed

Hughes, David A; Kircher, Martin; He, Zhisong; Guo, Song; Fairbrother, Genevieve L; Moreno, Carlos S; Khaitovich, Philipp; Stoneking, Mark

2015-03-19

Gene expression variation is a phenotypic trait of particular interest as it represents the initial link between genotype and other phenotypes. Analyzing how such variation apportions among and within groups allows for the evaluation of how genetic and environmental factors influence such traits. It also provides opportunities to identify genes and pathways that may have been influenced by non-neutral processes. Here we use a population genetics framework and next generation sequencing to evaluate how gene expression variation is apportioned among four human groups in a natural biological tissue, the placenta. We estimate that on average, 33.2%, 58.9%, and 7.8% of the placental transcriptome is explained by variation within individuals, among individuals, and among human groups, respectively. Additionally, when technical and biological traits are included in models of gene expression they each account for roughly 2% of total gene expression variation. Notably, the variation that is significantly different among groups is enriched in biological pathways associated with immune response, cell signaling, and metabolism. Many biological traits demonstrate correlated changes in expression in numerous pathways of potential interest to clinicians and evolutionary biologists. Finally, we estimate that the majority of the human placental transcriptome exhibits expression profiles consistent with neutrality; the remainder are consistent with stabilizing selection, directional selection, or diversifying selection. We apportion placental gene expression variation into individual, population, and biological trait factors and identify how each influence the transcriptome. Additionally, we advance methods to associate expression profiles with different forms of selection.

Fungal Gene Expression on Demand: an Inducible, Tunable, and Metabolism-Independent Expression System for Aspergillus niger▿†

PubMed Central

Meyer, Vera; Wanka, Franziska; van Gent, Janneke; Arentshorst, Mark; van den Hondel, Cees A. M. J. J.; Ram, Arthur F. J.

2011-01-01

Filamentous fungi are the cause of serious human and plant diseases but are also exploited in biotechnology as production platforms. Comparative genomics has documented their genetic diversity, and functional genomics and systems biology approaches are under way to understand the functions and interaction of fungal genes and proteins. In these approaches, gene functions are usually inferred from deletion or overexpression mutants. However, studies at these extreme points give only limited information. Moreover, many overexpression studies use metabolism-dependent promoters, often causing pleiotropic effects and thus limitations in their significance. We therefore established and systematically evaluated a tunable expression system for Aspergillus niger that is independent of carbon and nitrogen metabolism and silent under noninduced conditions. The system consists of two expression modules jointly targeted to a defined genomic locus. One module ensures constitutive expression of the tetracycline-dependent transactivator rtTA2S-M2, and one module harbors the rtTA2S-M2-dependent promoter that controls expression of the gene of interest (the Tet-on system). We show here that the system is tight, responds within minutes after inducer addition, and allows fine-tuning based on the inducer concentration or gene copy number up to expression levels higher than the expression levels of the gpdA promoter. We also validate the Tet-on system for the generation of conditional overexpression mutants and demonstrate its power when combined with a gene deletion approach. Finally, we show that the system is especially suitable when the functions of essential genes must be examined. PMID:21378046

The Study of HFE Genotypes and Its Expression Effect on Iron Status of Iranian Haemochromatosis, Iron Deficiency Anemia Patients, Iron-Taker and Non Iron-Taker Controls.

PubMed

Beiranvand, Elham; Abediankenari, Saeid; Rostamian, Mosayeb; Beiranvand, Behnoush; Naazeri, Saeed

2015-01-01

The role of HFE gene mutations or its expression in regulation of iron metabolism of hereditary haemochromatosis (HH) patients is remained controversial. Therefore here the correlation between two common HFE genotype (p.C282Y, p.H63D) and HFE gene expression with iron status in HH, iron deficiency anemia (IDA) and healthy Iranian participants was studied. For this purpose genotype determination was done by polymerase chain reaction--restriction fragment length polymorphism (PCR-RFLP). Real-Time PCR was applied for evaluation of HFE gene expression. Biochemical parameters and iron consumption were also assessed. Homozygote p.H63D mutation was seen in all HH patients and p.C282Y was not observed in any member of the population. A significant correlation was observed between serum ferritin (SF) level and gender or age of HH patients. p.H63D homozygote was seen to be able to significantly increase SF and transferrin saturation (TS) level without affecting on liver function. Our results also showed that iron consumption affects on TS level increasing. HFE gene expression level of IDA patients was significantly higher than other groups. Also the HFE gene expression was negatively correlated with TS. Finally, the main result of our study showed that loss of HFE function in HH is not derived from its gene expression inhibition and much higher HFE gene expression might lead to IDA. However we propose repeating of the study for more approval of our finding.

Genome-Wide Identification and Expression Profiling of Cytokinin Oxidase/Dehydrogenase (CKX) Genes Reveal Likely Roles in Pod Development and Stress Responses in Oilseed Rape (Brassica napus L.).

PubMed

Liu, Pu; Zhang, Chao; Ma, Jin-Qi; Zhang, Li-Yuan; Yang, Bo; Tang, Xin-Yu; Huang, Ling; Zhou, Xin-Tong; Lu, Kun; Li, Jia-Na

2018-03-16

Cytokinin oxidase/dehydrogenases (CKXs) play a critical role in the irreversible degradation of cytokinins, thereby regulating plant growth and development. Brassica napus is one of the most widely cultivated oilseed crops worldwide. With the completion of whole-genome sequencing of B. napus , genome-wide identification and expression analysis of the BnCKX gene family has become technically feasible. In this study, we identified 23 BnCKX genes and analyzed their phylogenetic relationships, gene structures, conserved motifs, protein subcellular localizations, and other properties. We also analyzed the expression of the 23 BnCKX genes in the B. napus cultivar Zhong Shuang 11 ('ZS11') by quantitative reverse-transcription polymerase chain reaction (qRT-PCR), revealing their diverse expression patterns. We selected four BnCKX genes based on the results of RNA-sequencing and qRT-PCR and compared their expression in cultivated varieties with extremely long versus short siliques. The expression levels of BnCKX5-1 , 5-2 , 6-1 , and 7-1 significantly differed between the two lines and changed during pod development, suggesting they might play roles in determining silique length and in pod development. Finally, we investigated the effects of treatment with the synthetic cytokinin 6-benzylaminopurine (6-BA) and the auxin indole-3-acetic acid (IAA) on the expression of the four selected BnCKX genes. Our results suggest that regulating BnCKX expression is a promising way to enhance the harvest index and stress resistance in plants.

Expression Divergence Is Correlated with Sequence Evolution but Not Positive Selection in Conifers.

PubMed

Hodgins, Kathryn A; Yeaman, Sam; Nurkowski, Kristin A; Rieseberg, Loren H; Aitken, Sally N

2016-06-01

The evolutionary and genomic determinants of sequence evolution in conifers are poorly understood, and previous studies have found only limited evidence for positive selection. Using RNAseq data, we compared gene expression profiles to patterns of divergence and polymorphism in 44 seedlings of lodgepole pine (Pinus contorta) and 39 seedlings of interior spruce (Picea glauca × engelmannii) to elucidate the evolutionary forces that shape their genomes and their plastic responses to abiotic stress. We found that rapidly diverging genes tend to have greater expression divergence, lower expression levels, reduced levels of synonymous site diversity, and longer proteins than slowly diverging genes. Similar patterns were identified for the untranslated regions, but with some exceptions. We found evidence that genes with low expression levels had a larger fraction of nearly neutral sites, suggesting a primary role for negative selection in determining the association between evolutionary rate and expression level. There was limited evidence for differences in the rate of positive selection among genes with divergent versus conserved expression profiles and some evidence supporting relaxed selection in genes diverging in expression between the species. Finally, we identified a small number of genes that showed evidence of site-specific positive selection using divergence data alone. However, estimates of the proportion of sites fixed by positive selection (α) were in the range of other plant species with large effective population sizes suggesting relatively high rates of adaptive divergence among conifers. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The centrality of RNA for engineering gene expression

PubMed Central

Chappell, James; Takahashi, Melissa K; Meyer, Sarai; Loughrey, David; Watters, Kyle E; Lucks, Julius

2013-01-01

Synthetic biology holds promise as both a framework for rationally engineering biological systems and a way to revolutionize how we fundamentally understand them. Essential to realizing this promise is the development of strategies and tools to reliably and predictably control and characterize sophisticated patterns of gene expression. Here we review the role that RNA can play towards this goal and make a case for why this versatile, designable, and increasingly characterizable molecule is one of the most powerful substrates for engineering gene expression at our disposal. We discuss current natural and synthetic RNA regulators of gene expression acting at key points of control – transcription, mRNA degradation, and translation. We also consider RNA structural probing and computational RNA structure predication tools as a way to study RNA structure and ultimately function. Finally, we discuss how next-generation sequencing methods are being applied to the study of RNA and to the characterization of RNA's many properties throughout the cell. PMID:24124015

Patterns of expression of position-dependent integrated transgenes in mouse embryo.

PubMed Central

Bonnerot, C; Grimber, G; Briand, P; Nicolas, J F

1990-01-01

The abilities to introduce foreign DNA into the genome of mice and to visualize gene expression at the single-cell level underlie a method for defining individual elements of a genetic program. We describe the use of an Escherichia coli lacZ reporter gene fused to the promoter of the gene for hypoxanthine phosphoribosyl transferase that is expressed in all tissues. Most transgenic mice (six of seven) obtained with this construct express the lacZ gene from the hypoxanthine phosphoribosyltransferase promoter. Unexpectedly, however, the expression is temporally and spatially regulated. Each transgenic line is characterized by a specific, highly reproducible pattern of lacZ expression. These results show that, for expression, the integrated construct must be complemented by elements of the genome. These elements exert dominant developmental control on the hypoxanthine phosphoribosyltransferase promoter. The expression patterns in some transgenic mice conform to a typological marker and in others to a subtle combination of typology and topography. These observations define discrete heterogeneities of cell types and of certain structures, particularly in the nervous system and in the mesoderm. This system opens opportunities for developmental studies by providing cellular, molecular, and genetic markers of cell types, cell states, and cells from developmental compartments. Finally this method illustrates that genes transduced or transposed to a different position in the genome acquire different spatiotemporal specificities, a result that has implications for evolution. Images PMID:1696727

Verification and Optimal Control of Context-Sensitive Probabilistic Boolean Networks Using Model Checking and Polynomial Optimization

PubMed Central

Hiraishi, Kunihiko

2014-01-01

One of the significant topics in systems biology is to develop control theory of gene regulatory networks (GRNs). In typical control of GRNs, expression of some genes is inhibited (activated) by manipulating external stimuli and expression of other genes. It is expected to apply control theory of GRNs to gene therapy technologies in the future. In this paper, a control method using a Boolean network (BN) is studied. A BN is widely used as a model of GRNs, and gene expression is expressed by a binary value (ON or OFF). In particular, a context-sensitive probabilistic Boolean network (CS-PBN), which is one of the extended models of BNs, is used. For CS-PBNs, the verification problem and the optimal control problem are considered. For the verification problem, a solution method using the probabilistic model checker PRISM is proposed. For the optimal control problem, a solution method using polynomial optimization is proposed. Finally, a numerical example on the WNT5A network, which is related to melanoma, is presented. The proposed methods provide us useful tools in control theory of GRNs. PMID:24587766

Quantitative and functional interrogation of parent-of-origin allelic expression biases in the brain

PubMed Central

Perez, Julio D; Rubinstein, Nimrod D; Fernandez, Daniel E; Santoro, Stephen W; Needleman, Leigh A; Ho-Shing, Olivia; Choi, John J; Zirlinger, Mariela; Chen, Shau-Kwaun; Liu, Jun S; Dulac, Catherine

2015-01-01

The maternal and paternal genomes play different roles in mammalian brains as a result of genomic imprinting, an epigenetic regulation leading to differential expression of the parental alleles of some genes. Here we investigate genomic imprinting in the cerebellum using a newly developed Bayesian statistical model that provides unprecedented transcript-level resolution. We uncover 160 imprinted transcripts, including 41 novel and independently validated imprinted genes. Strikingly, many genes exhibit parentally biased—rather than monoallelic—expression, with different magnitudes according to age, organ, and brain region. Developmental changes in parental bias and overall gene expression are strongly correlated, suggesting combined roles in regulating gene dosage. Finally, brain-specific deletion of the paternal, but not maternal, allele of the paternally-biased Bcl-x, (Bcl2l1) results in loss of specific neuron types, supporting the functional significance of parental biases. These findings reveal the remarkable complexity of genomic imprinting, with important implications for understanding the normal and diseased brain. DOI: http://dx.doi.org/10.7554/eLife.07860.001 PMID:26140685

Expression of DISC1-interactome members correlates with cognitive phenotypes related to schizophrenia.

PubMed

Rampino, Antonio; Walker, Rosie May; Torrance, Helen Scott; Anderson, Susan Maguire; Fazio, Leonardo; Di Giorgio, Annabella; Taurisano, Paolo; Gelao, Barbara; Romano, Raffaella; Masellis, Rita; Ursini, Gianluca; Caforio, Grazia; Blasi, Giuseppe; Millar, J Kirsty; Porteous, David John; Thomson, Pippa Ann; Bertolino, Alessandro; Evans, Kathryn Louise

2014-01-01

Cognitive dysfunction is central to the schizophrenia phenotype. Genetic and functional studies have implicated Disrupted-in-Schizophrenia 1 (DISC1), a leading candidate gene for schizophrenia and related psychiatric conditions, in cognitive function. Altered expression of DISC1 and DISC1-interactors has been identified in schizophrenia. Dysregulated expression of DISC1-interactome genes might, therefore, contribute to schizophrenia susceptibility via disruption of molecular systems required for normal cognitive function. Here, the blood RNA expression levels of DISC1 and DISC1-interacting proteins were measured in 63 control subjects. Cognitive function was assessed using neuropsychiatric tests and functional magnetic resonance imaging was used to assess the activity of prefrontal cortical regions during the N-back working memory task, which is abnormal in schizophrenia. Pairwise correlations between gene expression levels and the relationship between gene expression levels and cognitive function and N-back-elicited brain activity were assessed. Finally, the expression levels of DISC1, AKAP9, FEZ1, NDEL1 and PCM1 were compared between 63 controls and 69 schizophrenic subjects. We found that DISC1-interactome genes showed correlated expression in the blood of healthy individuals. The expression levels of several interactome members were correlated with cognitive performance and N-back-elicited activity in the prefrontal cortex. In addition, DISC1 and NDEL1 showed decreased expression in schizophrenic subjects compared to healthy controls. Our findings highlight the importance of the coordinated expression of DISC1-interactome genes for normal cognitive function and suggest that dysregulated DISC1 and NDEL1 expression might, in part, contribute to susceptibility for schizophrenia via disruption of prefrontal cortex-dependent cognitive functions.

Expression of DISC1-Interactome Members Correlates with Cognitive Phenotypes Related to Schizophrenia

PubMed Central

Rampino, Antonio; Walker, Rosie May; Torrance, Helen Scott; Anderson, Susan Maguire; Fazio, Leonardo; Di Giorgio, Annabella; Taurisano, Paolo; Gelao, Barbara; Romano, Raffaella; Masellis, Rita; Ursini, Gianluca; Caforio, Grazia; Blasi, Giuseppe; Millar, J. Kirsty; Porteous, David John; Thomson, Pippa Ann; Bertolino, Alessandro; Evans, Kathryn Louise

2014-01-01

Cognitive dysfunction is central to the schizophrenia phenotype. Genetic and functional studies have implicated Disrupted-in-Schizophrenia 1 (DISC1), a leading candidate gene for schizophrenia and related psychiatric conditions, in cognitive function. Altered expression of DISC1 and DISC1-interactors has been identified in schizophrenia. Dysregulated expression of DISC1-interactome genes might, therefore, contribute to schizophrenia susceptibility via disruption of molecular systems required for normal cognitive function. Here, the blood RNA expression levels of DISC1 and DISC1-interacting proteins were measured in 63 control subjects. Cognitive function was assessed using neuropsychiatric tests and functional magnetic resonance imaging was used to assess the activity of prefrontal cortical regions during the N-back working memory task, which is abnormal in schizophrenia. Pairwise correlations between gene expression levels and the relationship between gene expression levels and cognitive function and N-back-elicited brain activity were assessed. Finally, the expression levels of DISC1, AKAP9, FEZ1, NDEL1 and PCM1 were compared between 63 controls and 69 schizophrenic subjects. We found that DISC1-interactome genes showed correlated expression in the blood of healthy individuals. The expression levels of several interactome members were correlated with cognitive performance and N-back-elicited activity in the prefrontal cortex. In addition, DISC1 and NDEL1 showed decreased expression in schizophrenic subjects compared to healthy controls. Our findings highlight the importance of the coordinated expression of DISC1-interactome genes for normal cognitive function and suggest that dysregulated DISC1 and NDEL1 expression might, in part, contribute to susceptibility for schizophrenia via disruption of prefrontal cortex-dependent cognitive functions. PMID:24940743

Identification of a new gene regulatory circuit involving B cell receptor activated signaling using a combined analysis of experimental, clinical and global gene expression data

PubMed Central

Schrader, Alexandra; Meyer, Katharina; Walther, Neele; Stolz, Ailine; Feist, Maren; Hand, Elisabeth; von Bonin, Frederike; Evers, Maurits; Kohler, Christian; Shirneshan, Katayoon; Vockerodt, Martina; Klapper, Wolfram; Szczepanowski, Monika; Murray, Paul G.; Bastians, Holger; Trümper, Lorenz; Spang, Rainer; Kube, Dieter

2016-01-01

To discover new regulatory pathways in B lymphoma cells, we performed a combined analysis of experimental, clinical and global gene expression data. We identified a specific cluster of genes that was coherently expressed in primary lymphoma samples and suppressed by activation of the B cell receptor (BCR) through αIgM treatment of lymphoma cells in vitro. This gene cluster, which we called BCR.1, includes numerous cell cycle regulators. A reduced expression of BCR.1 genes after BCR activation was observed in different cell lines and also in CD10+ germinal center B cells. We found that BCR activation led to a delayed entry to and progression of mitosis and defects in metaphase. Cytogenetic changes were detected upon long-term αIgM treatment. Furthermore, an inverse correlation of BCR.1 genes with c-Myc co-regulated genes in distinct groups of lymphoma patients was observed. Finally, we showed that the BCR.1 index discriminates activated B cell-like and germinal centre B cell-like diffuse large B cell lymphoma supporting the functional relevance of this new regulatory circuit and the power of guided clustering for biomarker discovery. PMID:27166259

EXTRA-EMBRYONIC-SPECIFIC IMPRINTED EXPRESSION IS RESTRICTED TO DEFINED LINEAGES IN THE POST-IMPLANTATION EMBRYO

PubMed Central

Hudson, Quanah J.; Seidl, Christine I.M.; Kulinski, Tomasz M.; Huang, Ru; Warczok, Katarzyna E.; Bittner, Romana; Bartolomei, Marisa S.; Barlow, Denise P.

2011-01-01

A subset of imprinted genes in the mouse have been reported to show imprinted expression that is restricted to the placenta, a short-lived extra-embryonic organ. Notably these so-called 'placental-specific' imprinted genes are expressed from both parental alleles in embryo and adult tissues. The placenta is an embryonic-derived organ that is closely associated with maternal tissue and as a consequence, maternal contamination can be mistaken for maternal-specific imprinted expression. The complexity of the placenta, which arises from multiple embryonic lineages, poses additional problems in accurately assessing allele-specific repressive epigenetic modifications in genes that also show lineage-specific silencing in this organ. These problems require that extra evidence be obtained to support the imprinted status of genes whose imprinted expression is restricted to the placenta. We show here that the extra-embryonic visceral yolk sac (VYS), a nutritive membrane surrounding the developing embryo, shows a similar 'extra-embryonic-lineage-specific' pattern of imprinted expression. We present an improved enzymatic technique for separating the bilaminar VYS and show that this pattern of imprinted expression is restricted to the endoderm layer. Finally, we show that VYS 'extra-embryonic-lineage-specific' imprinted expression is regulated by DNA methylation in a similar manner as shown for genes showing multi-lineage imprinted expression in extra-embryonic, embryonic and adult tissues. These results show that the VYS is an improved model for studying the epigenetic mechanisms regulating extra-embryonic-lineage-specific imprinted expression. PMID:21354127

Expression of the Arginine Deiminase Pathway Genes in Lactobacillus sakei Is Strain Dependent and Is Affected by the Environmental pH

PubMed Central

Rimaux, T.; Rivière, A.; Illeghems, K.; Weckx, S.; De Vuyst, L.

2012-01-01

The adaptation of Lactobacillus sakei to a meat environment is reflected in its metabolic potential. For instance, the ability to utilize arginine through the arginine deiminase (ADI) pathway, resulting in additional ATP, represents a competitive benefit. In L. sakei CTC 494, the arc operon (arcABCTDR) shows the same gene order and organization as that in L. sakei 23K, the genome sequence of which is known. However, differences in relative gene expression were found, and these seemed to be optimal in different growth phases, namely, the highest relative gene expression level was in the end exponential growth phase in the case of L. sakei CTC 494 and in the mid-exponential growth phase of L. sakei 23K. Also, the environmental pH influenced the relative expression level of the arc operon, as shown for L. sakei CTC 494, with the highest relative expression level occurring at the optimal pH for growth (pH 6.0). Deviations from this optimal pH (pH 5.0 and pH 7.0) resulted in an overall decline of the relative expression level of all genes of the arc operon. Furthermore, a differential relative expression of the individual genes of the arc operon was found, with the highest relative gene expression occurring for the first two genes of the arc operon (arcA and arcB). Finally, it was shown that some L. sakei strains were able to convert agmatine into putrescine, suggesting an operational agmatine deiminase pathway in these strains, a metabolic trait that is undesirable in meat fermentations. This study shows that this metabolic trait is most probably encoded by a previously erroneously annotated second putative arc operon. PMID:22544250

IL-17A Mediates a Selective Gene Expression Profile in Asthmatic Human Airway Smooth Muscle Cells

PubMed Central

Dragon, Stéphane; Hirst, Stuart J.; Lee, Tak H.

2014-01-01

Airway smooth muscle (ASM) cells are thought to contribute to the pathogenesis of allergic asthma by orchestrating and perpetuating airway inflammation and remodeling responses. In this study, we evaluated the IL-17RA signal transduction and gene expression profile in ASM cells from subjects with mild asthma and healthy individuals. Human primary ASM cells were treated with IL-17A and probed by the Affymetrix GeneChip array, and gene targets were validated by real-time quantitative RT-PCR. Genomic analysis underlined the proinflammatory nature of IL-17A, as multiple NF-κB regulatory factors and chemokines were induced in ASM cells. Transcriptional regulators consisting of primary response genes were overrepresented and displayed dynamic expression profiles. IL-17A poorly enhanced IL-1β or IL-22 gene responses in ASM cells from both subjects with mild asthma and healthy donors. Interestingly, protein modifications to the NF-κB regulatory network were not observed after IL-17A stimulation, although oscillations in IκBε expression were detected. ASM cells from subjects with mild asthma up-regulated more genes with greater overall variability in response to IL-17A than from healthy donors. Finally, in response to IL-17A, ASM cells displayed rapid activation of the extracellular signal–regulated kinase/ribosomal S6 kinase signaling pathway and increased nuclear levels of phosphorylated extracellular signal–regulated kinase. Taken together, our results suggest that IL-17A mediated modest gene expression response, which, in cooperation with the NF-κB signaling network, may regulate the gene expression profile in ASM cells. PMID:24393021

Stability-driven nonnegative matrix factorization to interpret spatial gene expression and build local gene networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Siqi; Joseph, Antony; Hammonds, Ann S.

Spatial gene expression patterns enable the detection of local covariability and are extremely useful for identifying local gene interactions during normal development. The abundance of spatial expression data in recent years has led to the modeling and analysis of regulatory networks. The inherent complexity of such data makes it a challenge to extract biological information. We developed staNMF, a method that combines a scalable implementation of nonnegative matrix factorization (NMF) with a new stability-driven model selection criterion. When applied to a set of Drosophila early embryonic spatial gene expression images, one of the largest datasets of its kind, staNMF identifiedmore » 21 principal patterns (PP). Providing a compact yet biologically interpretable representation of Drosophila expression patterns, PP are comparable to a fate map generated experimentally by laser ablation and show exceptional promise as a data-driven alternative to manual annotations. Our analysis mapped genes to cell-fate programs and assigned putative biological roles to uncharacterized genes. Finally, we used the PP to generate local transcription factor regulatory networks. Spatially local correlation networks were constructed for six PP that span along the embryonic anterior-posterior axis. Using a two-tail 5% cutoff on correlation, we reproduced 10 of the 11 links in the well-studied gap gene network. In conclusion, the performance of PP with the Drosophila data suggests that staNMF provides informative decompositions and constitutes a useful computational lens through which to extract biological insight from complex and often noisy gene expression data.« less

Stability-driven nonnegative matrix factorization to interpret spatial gene expression and build local gene networks

DOE PAGES

Wu, Siqi; Joseph, Antony; Hammonds, Ann S.; ...

2016-04-06

Spatial gene expression patterns enable the detection of local covariability and are extremely useful for identifying local gene interactions during normal development. The abundance of spatial expression data in recent years has led to the modeling and analysis of regulatory networks. The inherent complexity of such data makes it a challenge to extract biological information. We developed staNMF, a method that combines a scalable implementation of nonnegative matrix factorization (NMF) with a new stability-driven model selection criterion. When applied to a set of Drosophila early embryonic spatial gene expression images, one of the largest datasets of its kind, staNMF identifiedmore » 21 principal patterns (PP). Providing a compact yet biologically interpretable representation of Drosophila expression patterns, PP are comparable to a fate map generated experimentally by laser ablation and show exceptional promise as a data-driven alternative to manual annotations. Our analysis mapped genes to cell-fate programs and assigned putative biological roles to uncharacterized genes. Finally, we used the PP to generate local transcription factor regulatory networks. Spatially local correlation networks were constructed for six PP that span along the embryonic anterior-posterior axis. Using a two-tail 5% cutoff on correlation, we reproduced 10 of the 11 links in the well-studied gap gene network. In conclusion, the performance of PP with the Drosophila data suggests that staNMF provides informative decompositions and constitutes a useful computational lens through which to extract biological insight from complex and often noisy gene expression data.« less

Expression at the imprinted dlk1-gtl2 locus is regulated by proneural genes in the developing telencephalon.

PubMed

Seibt, Julie; Armant, Olivier; Le Digarcher, Anne; Castro, Diogo; Ramesh, Vidya; Journot, Laurent; Guillemot, François; Vanderhaeghen, Pierre; Bouschet, Tristan

2012-01-01

Imprinting is an epigenetic mechanism that restrains the expression of about 100 genes to one allele depending on its parental origin. Several imprinted genes are implicated in neurodevelopmental brain disorders, such as autism, Angelman, and Prader-Willi syndromes. However, how expression of these imprinted genes is regulated during neural development is poorly understood. Here, using single and double KO animals for the transcription factors Neurogenin2 (Ngn2) and Achaete-scute homolog 1 (Ascl1), we found that the expression of a specific subset of imprinted genes is controlled by these proneural genes. Using in situ hybridization and quantitative PCR, we determined that five imprinted transcripts situated at the Dlk1-Gtl2 locus (Dlk1, Gtl2, Mirg, Rian, Rtl1) are upregulated in the dorsal telencephalon of Ngn2 KO mice. This suggests that Ngn2 influences the expression of the entire Dlk1-Gtl2 locus, independently of the parental origin of the transcripts. Interestingly 14 other imprinted genes situated at other imprinted loci were not affected by the loss of Ngn2. Finally, using Ngn2/Ascl1 double KO mice, we show that the upregulation of genes at the Dlk1-Gtl2 locus in Ngn2 KO animals requires a functional copy of Ascl1. Our data suggest a complex interplay between proneural genes in the developing forebrain that control the level of expression at the imprinted Dlk1-Gtl2 locus (but not of other imprinted genes). This raises the possibility that the transcripts of this selective locus participate in the biological effects of proneural genes in the developing telencephalon.

Expression at the Imprinted Dlk1-Gtl2 Locus Is Regulated by Proneural Genes in the Developing Telencephalon

PubMed Central

Seibt, Julie; Armant, Olivier; Le Digarcher, Anne; Castro, Diogo; Ramesh, Vidya; Journot, Laurent; Guillemot, François; Vanderhaeghen, Pierre; Bouschet, Tristan

2012-01-01

Imprinting is an epigenetic mechanism that restrains the expression of about 100 genes to one allele depending on its parental origin. Several imprinted genes are implicated in neurodevelopmental brain disorders, such as autism, Angelman, and Prader-Willi syndromes. However, how expression of these imprinted genes is regulated during neural development is poorly understood. Here, using single and double KO animals for the transcription factors Neurogenin2 (Ngn2) and Achaete-scute homolog 1 (Ascl1), we found that the expression of a specific subset of imprinted genes is controlled by these proneural genes. Using in situ hybridization and quantitative PCR, we determined that five imprinted transcripts situated at the Dlk1-Gtl2 locus (Dlk1, Gtl2, Mirg, Rian, Rtl1) are upregulated in the dorsal telencephalon of Ngn2 KO mice. This suggests that Ngn2 influences the expression of the entire Dlk1-Gtl2 locus, independently of the parental origin of the transcripts. Interestingly 14 other imprinted genes situated at other imprinted loci were not affected by the loss of Ngn2. Finally, using Ngn2/Ascl1 double KO mice, we show that the upregulation of genes at the Dlk1-Gtl2 locus in Ngn2 KO animals requires a functional copy of Ascl1. Our data suggest a complex interplay between proneural genes in the developing forebrain that control the level of expression at the imprinted Dlk1-Gtl2 locus (but not of other imprinted genes). This raises the possibility that the transcripts of this selective locus participate in the biological effects of proneural genes in the developing telencephalon. PMID:23139813

Weighted gene co‑expression network analysis in identification of key genes and networks for ischemic‑reperfusion remodeling myocardium.

PubMed

Guo, Nan; Zhang, Nan; Yan, Liqiu; Lian, Zheng; Wang, Jiawang; Lv, Fengfeng; Wang, Yunfei; Cao, Xufen

2018-06-14

Acute myocardial infarction induces ventricular remodeling, which is implicated in dilated heart and heart failure. The pathogenical mechanism of myocardium remodeling remains to be elucidated. The aim of the present study was to identify key genes and networks for myocardium remodeling following ischemia‑reperfusion (IR). First, the mRNA expression data from the National Center for Biotechnology Information database were downloaded to identify differences in mRNA expression of the IR heart at days 2 and 7. Then, weighted gene co‑expression network analysis, hierarchical clustering, protein‑protein interaction (PPI) network, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were used to identify key genes and networks for the heart remodeling process following IR. A total of 3,321 differentially expressed genes were identified during the heart remodeling process. A total of 6 modules were identified through gene co‑expression network analysis. GO and KEGG analysis results suggested that each module represented a different biological function and was associated with different pathways. Finally, hub genes of each module were identified by PPI network construction. The present study revealed that heart remodeling following IR is a complicated process, involving extracellular matrix organization, neural development, apoptosis and energy metabolism. The dysregulated genes, including SRC proto‑oncogene, non‑receptor tyrosine kinase, discs large MAGUK scaffold protein 1, ATP citrate lyase, RAN, member RAS oncogene family, tumor protein p53, and polo like kinase 2, may be essential for heart remodeling following IR and may be used as potential targets for the inhibition of heart remodeling following acute myocardial infarction.

Identification of Differentially Expressed Genes in Blood Cells of Narcolepsy Patients

PubMed Central

Tanaka, Susumu; Honda, Yutaka; Honda, Makoto

2007-01-01

Study Objective: A close association between the human leukocyte antigen (HLA)-DRB1*1501/DQB1*0602 and abnormalities in some inflammatory cytokines have been demonstrated in narcolepsy. Specific alterations in the immune system have been suggested to occur in this disorder. We attempted to identify alterations in gene expression underlying the abnormalities in the blood cells of narcoleptic patients. Designs: Total RNA from 12 narcolepsy-cataplexy patients and from 12 age- and sex-matched healthy controls were pooled. The pooled samples were initially screened for candidate genes for narcolepsy by differential display analysis using annealing control primers (ACP). The second screening of the samples was carried out by semiquantitative PCR using gene-specific primers. Finally, the expression levels of the candidate genes were further confirmed by quantitative real-time PCR using a new set of samples (20 narcolepsy-cataplexy patients and 20 healthy controls). Results: The second screening revealed differential expression of 4 candidate genes. Among them, MX2 was confirmed as a significantly down-regulated gene in the white blood cells of narcoleptic patients by quantitative real-time PCR. Conclusion: We found the MX2 gene to be significantly less expressed in comparison with normal subjects in the white blood cells of narcoleptic patients. This gene is relevant to the immune system. Although differential display analysis using ACP technology has a limitation in that it does not help in determining the functional mechanism underlying sleep/wakefulness dysregulation, it is useful for identifying novel genetic factors related to narcolepsy, such as HLA molecules. Further studies are required to explore the functional relationship between the MX2 gene and narcolepsy pathophysiology. Citation: Tanaka S; Honda Y; Honda M. Identification of differentially expressed genes in blood cells of narcolepsy patients. SLEEP 2007;30(8):974-979. PMID:17702266

Network-based co-expression analysis for exploring the potential diagnostic biomarkers of metastatic melanoma.

PubMed

Wang, Li-Xin; Li, Yang; Chen, Guan-Zhi

2018-01-01

Metastatic melanoma is an aggressive skin cancer and is one of the global malignancies with high mortality and morbidity. It is essential to identify and verify diagnostic biomarkers of early metastatic melanoma. Previous studies have systematically assessed protein biomarkers and mRNA-based expression characteristics. However, molecular markers for the early diagnosis of metastatic melanoma have not been identified. To explore potential regulatory targets, we have analyzed the gene microarray expression profiles of malignant melanoma samples by co-expression analysis based on the network approach. The differentially expressed genes (DEGs) were screened by the EdgeR package of R software. A weighted gene co-expression network analysis (WGCNA) was used for the identification of DEGs in the special gene modules and hub genes. Subsequently, a protein-protein interaction network was constructed to extract hub genes associated with gene modules. Finally, twenty-four important hub genes (RASGRP2, IKZF1, CXCR5, LTB, BLK, LINGO3, CCR6, P2RY10, RHOH, JUP, KRT14, PLA2G3, SPRR1A, KRT78, SFN, CLDN4, IL1RN, PKP3, CBLC, KRT16, TMEM79, KLK8, LYPD3 and LYPD5) were treated as valuable factors involved in the immune response and tumor cell development in tumorigenesis. In addition, a transcriptional regulatory network was constructed for these specific modules or hub genes, and a few core transcriptional regulators were found to be mostly associated with our hub genes, including GATA1, STAT1, SP1, and PSG1. In summary, our findings enhance our understanding of the biological process of malignant melanoma metastasis, enabling us to identify specific genes to use for diagnostic and prognostic markers and possibly for targeted therapy.

Molecular evolution and expression profile of the chemerine encoding gene RARRES2 in baboon and chimpanzee.

PubMed

González-Alvarez, Rafael; Garza-Rodríguez, María de Lourdes; Delgado-Enciso, Iván; Treviño-Alvarado, Víctor Manuel; Canales-Del-Castillo, Ricardo; Martínez-De-Villarreal, Laura Elia; Lugo-Trampe, Ángel; Tejero, María Elizabeth; Schlabritz-Loutsevitch, Natalia E; Rocha-Pizaña, María Del Refugio; Cole, Shelley A; Reséndez-Pérez, Diana; Moises-Alvarez, Mario; Comuzzie, Anthony G; Barrera-Saldaña, Hugo Alberto; Garza-Guajardo, Raquel; Barboza-Quintana, Oralia; Rodríguez-Sánchez, Irám Pablo

2015-06-12

Chemerin, encoded by the retinoic acid receptor responder 2 (RARRES2) gene is an adipocytesecreted protein with autocrine/paracrine functions in adipose tissue, metabolism and inflammation with a recently described function in vascular tone regulation, liver, steatosis, etc. This molecule is believed to represent a critical endocrine signal linking obesity to diabetes. There are no data available regarding evolution of RARRES2 in non-human primates and great apes. Expression profile and orthology in RARRES2 genes are unknown aspects in the biology of this multigene family in primates. Thus; we attempt to describe expression profile and phylogenetic relationship as complementary knowledge in the function of this gene in primates. To do that, we performed A RT-PCR from different tissues obtained during necropsies. Also we tested the hypotheses of positive evolution, purifying selection, and neutrality. And finally a phylogenetic analysis was made between primates RARRES2 protein. RARRES2 transcripts were present in liver, lung, adipose tissue, ovary, pancreas, heart, hypothalamus and pituitary tissues. Expression in kidney and leukocytes were not detectable in either species. It was determined that the studied genes are orthologous. RARRES2 evolution fits the hypothesis of purifying selection. Expression profiles of the RARRES2 gene are similar in baboons and chimpanzees and are also phylogenetically related.

Transcriptome profiling of the whitefly Bemisia tabaci reveals stage-specific gene expression signatures for thiamethoxam resistance

PubMed Central

Yang, N; Xie, W; Jones, CM; Bass, C; Jiao, X; Yang, X; Liu, B; Li, R; Zhang, Y

2013-01-01

Bemisia tabaci has developed high levels of resistance to many insecticides including the neonicotinoids and there is strong evidence that for some compounds resistance is stage-specific. To investigate the molecular basis of B. tabaci resistance to the neonicotinoid thiamethoxam we used a custom whitefly microarray to compare gene expression in the egg, nymph and adult stages of a thiamethoxam-resistant strain (TH-R) with a susceptible strain (TH-S). Gene ontology and bioinformatic analyses revealed that in all life stages many of the differentially expressed transcripts encoded enzymes involved in metabolic processes and/or metabolism of xenobiotics. Several of these are candidate resistance genes and include the cytochrome P450 CYP6CM1, which has been shown to confer resistance to several neonicotinoids previously, a P450 belonging to the Cytochrome P450s 4 family and a glutathione S-transferase (GST) belonging to the sigma class. Finally several ATP-binding cassette transporters of the ABCG subfamily were highly over-expressed in the adult stage of the TH-R strain and may play a role in resistance by active efflux. Here, we evaluated both common and stage-specific gene expression signatures and identified several candidate resistance genes that may underlie B. tabaci resistance to thiamethoxam. PMID:23889345

Characterization of a novel rice gene OsATX and modulation of its expression by components of the stress signalling pathways.

PubMed

Agrawal, Ganesh K; Rakwal, Randeep; Jwa, N-S; Agrawal, Vishwanath P

2002-09-01

In our search to identify gene(s) involved in the rice self-defense responses, we cloned a novel rice (Oryza sativa L. cv. Nipponbare) gene, OsATX, a single copy gene, from the JA treated rice seedling leaves cDNA library. This gene encodes a 69 amino acid polypeptide with a predicted molecular mass of 7649.7 and a pI of 5.6. OsATX was responsive to cutting (wounding by cutting the excised leaf), over its weak constitutive expression in the healthy leaves. The critical signalling molecules, jasmonic acid (JA), salicylic acid (SA), abscisic acid (ABA), and hydrogen peroxide, together with protein phosphatase inhibitors, effectively up-regulated the OsATX expression with time, over the excised leaf cut control, whereas ethylene had no affect. Furthermore, copper, a heavy metal, also up-regulated OsATX expression. Moreover, induced expression of OsATX mRNA was influenced by light signal(s), and showed a requirement for de novo synthesized protein factors. Additionally, co-application of either JA or ABA with SA drastically suppressed the induced OsATX mRNA level. Finally, the blast pathogen, Magnaporthe grisea, triggered OsATX mRNA accumulation. These results strongly suggest a function/role(s) for OsATX in defense/stress responses in rice.

Transcriptional regulation of brain gene expression in response to a territorial intrusion

PubMed Central

Sanogo, Yibayiri O.; Band, Mark; Blatti, Charles; Sinha, Saurabh; Bell, Alison M.

2012-01-01

Aggressive behaviour associated with territorial defence is widespread and has fitness consequences. However, excess aggression can interfere with other important biological functions such as immunity and energy homeostasis. How the expression of complex behaviours such as aggression is regulated in the brain has long intrigued ethologists, but has only recently become amenable for molecular dissection in non-model organisms. We investigated the transcriptomic response to territorial intrusion in four brain regions in breeding male threespined sticklebacks using expression microarrays and quantitative polymerase chain reaction (qPCR). Each region of the brain had a distinct genomic response to a territorial challenge. We identified a set of genes that were upregulated in the diencephalon and downregulated in the cerebellum and the brain stem. Cis-regulatory network analysis suggested transcription factors that regulated or co-regulated genes that were consistently regulated in all brain regions and others that regulated gene expression in opposing directions across brain regions. Our results support the hypothesis that territorial animals respond to social challenges via transcriptional regulation of genes in different brain regions. Finally, we found a remarkably close association between gene expression and aggressive behaviour at the individual level. This study sheds light on the molecular mechanisms in the brain that underlie the response to social challenges. PMID:23097509

Statistical Test of Expression Pattern (STEPath): a new strategy to integrate gene expression data with genomic information in individual and meta-analysis studies.

PubMed

Martini, Paolo; Risso, Davide; Sales, Gabriele; Romualdi, Chiara; Lanfranchi, Gerolamo; Cagnin, Stefano

2011-04-11

In the last decades, microarray technology has spread, leading to a dramatic increase of publicly available datasets. The first statistical tools developed were focused on the identification of significant differentially expressed genes. Later, researchers moved toward the systematic integration of gene expression profiles with additional biological information, such as chromosomal location, ontological annotations or sequence features. The analysis of gene expression linked to physical location of genes on chromosomes allows the identification of transcriptionally imbalanced regions, while, Gene Set Analysis focuses on the detection of coordinated changes in transcriptional levels among sets of biologically related genes. In this field, meta-analysis offers the possibility to compare different studies, addressing the same biological question to fully exploit public gene expression datasets. We describe STEPath, a method that starts from gene expression profiles and integrates the analysis of imbalanced region as an a priori step before performing gene set analysis. The application of STEPath in individual studies produced gene set scores weighted by chromosomal activation. As a final step, we propose a way to compare these scores across different studies (meta-analysis) on related biological issues. One complication with meta-analysis is batch effects, which occur because molecular measurements are affected by laboratory conditions, reagent lots and personnel differences. Major problems occur when batch effects are correlated with an outcome of interest and lead to incorrect conclusions. We evaluated the power of combining chromosome mapping and gene set enrichment analysis, performing the analysis on a dataset of leukaemia (example of individual study) and on a dataset of skeletal muscle diseases (meta-analysis approach). In leukaemia, we identified the Hox gene set, a gene set closely related to the pathology that other algorithms of gene set analysis do not identify, while the meta-analysis approach on muscular disease discriminates between related pathologies and correlates similar ones from different studies. STEPath is a new method that integrates gene expression profiles, genomic co-expressed regions and the information about the biological function of genes. The usage of the STEPath-computed gene set scores overcomes batch effects in the meta-analysis approaches allowing the direct comparison of different pathologies and different studies on a gene set activation level.

[The induction of neovascularization in chorioallantoic membrane of chicken embryos transfected by a recombinant plasmid containing human angiogenin gene].

PubMed

Avdeeva, S V; Khaĭdarova, N V; Logunov, D Iu; Neugodova, G L; Sevast'ianova, G A; Tarantul, V Z; Naroditskiĭ, B S

2003-01-01

A method was elaborated to evaluate the biological activity of expression products of gene in the plasmid vectors, which are crucial for the synthesis of growth factor of blood vessels. It was proven as possible that the chrioallantonic membrane (CAM) of chicken's embryos could be transfected by recombinant plasmids containing both the reporter and target genes. The efficiency of CAM transfection was assessed by a plasmid carrying the reporter gene of green fluorescent protein (GFP). Finally, it was demonstrated that, at an infiltration of the recombinant plasmid containing the human angiogenine gene, its expression products induce the neovascularization in the CAM cells of chicken's embryos and stimulate an accretion in vessels of the 1st, 2nd and 3d orders.

Analysis of gene expression changes in relation to toxicity and tumorigenesis in the livers of Big Blue transgenic rats fed comfrey (Symphytum officinale)

PubMed Central

Mei, Nan; Guo, Lei; Zhang, Lu; Shi, Leming; Sun, Yongming Andrew; Fung, Chris; Moland, Carrie L; Dial, Stacey L; Fuscoe, James C; Chen, Tao

2006-01-01

Background Comfrey is consumed by humans as a vegetable and a tea, and has been used as an herbal medicine for more than 2000 years. Comfrey, however, is hepatotoxic in livestock and humans and carcinogenic in experimental animals. Our previous study suggested that comfrey induces liver tumors by a genotoxic mechanism and that the pyrrolizidine alkaloids in the plant are responsible for mutation induction and tumor initiation in rat liver. Results In this study, we identified comfrey-induced gene expression profile in the livers of rats. Groups of 6 male transgenic Big Blue rats were fed a basal diet and a diet containing 8% comfrey roots, a dose that resulted in liver tumors in a previous carcinogenicity bioassay. The animals were treated for 12 weeks and sacrificed one day after the final treatment. We used a rat microarray containing 26,857 genes to perform genome-wide gene expression studies. Dietary comfrey resulted in marked changes in liver gene expression, as well as in significant decreases in the body weight and increases in liver mutant frequency. When a two-fold cutoff value and a P-value less than 0.01 were selected, 2,726 genes were identified as differentially expressed in comfrey-fed rats compared to control animals. Among these genes, there were 1,617 genes associated by Ingenuity Pathway Analysis with particular functions, and the differentially expressed genes in comfrey-fed rat livers were involved in metabolism, injury of endothelial cells, and liver injury and abnormalities, including liver fibrosis and cancer development. Conclusion The gene expression profile provides us a better understanding of underlying mechanisms for comfrey-induced hepatic toxicity. Integration of gene expression changes with known pathological changes can be used to formulate a mechanistic scheme for comfrey-induced liver toxicity and tumorigenesis. PMID:17118137

Fight or flight? - Flight increases immune gene expression but does not help to fight an infection.

PubMed

Woestmann, L; Kvist, J; Saastamoinen, M

2017-03-01

Flight represents a key trait in most insects, being energetically extremely demanding, yet often necessary for foraging and reproduction. Additionally, dispersal via flight is especially important for species living in fragmented landscapes. Even though, based on life-history theory, a negative relationship may be expected between flight and immunity, a number of previous studies have indicated flight to induce an increased immune response. In this study, we assessed whether induced immunity (i.e. immune gene expression) in response to 15-min forced flight treatment impacts individual survival of bacterial infection in the Glanville fritillary butterfly (Melitaea cinxia). We were able to confirm previous findings of flight-induced immune gene expression, but still observed substantially stronger effects on both gene expression levels and life span due to bacterial infection compared to flight treatment. Even though gene expression levels of some immunity-related genes were elevated due to flight, these individuals did not show increased survival of bacterial infection, indicating that flight-induced immune activation does not completely protect them from the negative effects of bacterial infection. Finally, an interaction between flight and immune treatment indicated a potential trade-off: flight treatment increased immune gene expression in naïve individuals only, whereas in infected individuals no increase in immune gene expression was induced by flight. Our results suggest that the up-regulation of immune genes upon flight is based on a general stress response rather than reflecting an adaptive response to cope with potential infections during flight or in new habitats. © 2016 The Authors. Journal of Evolutionary Biology Published by John Wiley & Sons ltd on behalf of European Society for Evolutionary Biology.

AmpA protein functions by different mechanisms to influence early cell type specification and to modulate cell adhesion and actin polymerization in Dictyostelium discoideum

PubMed Central

Cost, Hoa N.; Noratel, Elizabeth F.; Blumberg, Daphne D.

2013-01-01

The Dictyostelium discoideum ampA gene encodes a multifunctional regulator protein that modulates cell–cell and cell–substrate adhesions and actin polymerization during growth and is necessary for correct cell type specification and patterning during development. Insertional inactivation of the ampA gene results in defects that define two distinct roles for the ampA gene during development. AmpA is necessary in a non-cell autonomous manner to prevent premature expression of a prespore gene marker. It is also necessary in a cell autonomous manner for the anterior like cells, which express the ampA gene, to migrate to the upper cup during culmination. It is also necessary to prevent excessive cell–cell agglutination when cells are developed in a submerged suspension culture. Here, we demonstrate that a supernatant source of AmpA protein, added extracellularly, can prevent the premature mis-expression of the prespore marker. Synthetic oligopeptides are used to identify the domain of the AmpA protein that is important for preventing cells from mis-expressing the prespore gene. We further demonstrate that a factor capable of inducing additional cells to express the prespore gene marker accumulates extracellularly in the absence of AmpA protein. While the secreted AmpA acts extracellularly to suppress prespore gene expression, the effects of AmpA on cell agglutination and on actin polymerization in growing cells are not due to an extracellular role of secreted AmpA protein. Rather, these effects appear to reflect a distinct cell autonomous role of the ampA gene. Finally, we show that secretion of AmpA protein is brought about by elevating the levels of expression of ampA so that the protein accumulates to an excessive level. PMID:23911723

Co-expression of mitosis-regulating genes contributes to malignant progression and prognosis in oligodendrogliomas

PubMed Central

Liu, Yanwei; Hu, Huimin; Zhang, Chuanbao; Wang, Haoyuan; Zhang, Wenlong; Wang, Zheng; Li, Mingyang; Zhang, Wei; Zhou, Dabiao; Jiang, Tao

2015-01-01

The clinical prognosis of patients with glioma is determined by tumor grades, but tumors of different subtypes with equal malignancy grade usually have different prognosis that is largely determined by genetic abnormalities. Oligodendrogliomas (ODs) are the second most common type of gliomas. In this study, integrative analyses found that distribution of TCGA transcriptomic subtypes was associated with grade progression in ODs. To identify critical gene(s) associated with tumor grades and TCGA subtypes, we analyzed 34 normal brain tissue (NBT), 146 WHO grade II and 130 grade III ODs by microarray and RNA sequencing, and identified a co-expression network of six genes (AURKA, NDC80,CENPK, KIAA0101, TIMELESS and MELK) that was associated with tumor grades and TCGA subtypes as well as Ki-67 expression. Validation of the six genes was performed by qPCR in additional 28 ODs. Importantly, these genes also were validated in four high-grade recurrent gliomas and the initial lower-grade gliomas resected from the same patients. Finally, the RNA data on two genes with the highest discrimination potential (AURKA and NDC80) and Ki-67 were validated on an independent cohort (5 NBTs and 86 ODs) by immunohistochemistry. Knockdown of AURKA and NDC80 by siRNAs suppressed Ki-67 expression and proliferation of gliomas cells. Survival analysis showed that high expression of the six genes corporately indicated a poor survival outcome. Correlation and protein interaction analysis provided further evidence for this co-expression network. These data suggest that the co-expression of the six mitosis-regulating genes was associated with malignant progression and prognosis in ODs. PMID:26468983

Transcriptome Analysis of the Brucella abortus BvrR/BvrS Two-Component Regulatory System

PubMed Central

Viadas, Cristina; Rodríguez, María C.; Sangari, Felix J.; Gorvel, Jean-Pierre; García-Lobo, Juan M.; López-Goñi, Ignacio

2010-01-01

Background The two-component BvrR/BvrS system is essential for Brucella abortus virulence. It was shown previously that its dysfunction alters the expression of some major outer membrane proteins and the pattern of lipid A acylation. To determine the genes regulated by BvrR/BvrS, we performed a whole-genome microarray analysis using B. abortus RNA obtained from wild type and bvrR mutant cells grown in the same conditions. Methodology/Principal Findings A total of 127 differentially expressed genes were found: 83 were over expressed and 44 were less expressed in the bvrR mutant. Two operons, the phosphotransferase system and the maltose transport system, were down-regulated. Several genes involved in cell envelope or outer membrane biogenesis were differentially expressed: genes for outer membrane proteins (omp25a, omp25d), lipoproteins, LPS and fatty acid biosynthesis, stress response proteins, chaperones, flagellar genes, and twelve genes encoding ABC transport systems. Ten genes related with carbon metabolism (pckA and fumB among others) were up-regulated in the bvrR mutant, and denitrification genes (nirK, norC and nosZ) were also regulated. Notably, seven transcriptional regulators were affected, including VjbR, ExoR and OmpR that were less expressed in the bvrR mutant. Finally, the expression of eleven genes which have been previously related with Brucella virulence was also altered. Conclusions/Significance All these data corroborate the impact of BvrR/BvrS on cell envelope modulation, confirm that this system controls the carbon and nitrogen metabolism, and suggest a cross-talk among some regulators to adjust the Brucella physiology to the shift expected to occur during the transit from the extracellular to the intracellular niche. PMID:20422049

Fluid Mechanics, Arterial Disease, and Gene Expression.

PubMed

Tarbell, John M; Shi, Zhong-Dong; Dunn, Jessilyn; Jo, Hanjoong

2014-01-01

This review places modern research developments in vascular mechanobiology in the context of hemodynamic phenomena in the cardiovascular system and the discrete localization of vascular disease. The modern origins of this field are traced, beginning in the 1960s when associations between flow characteristics, particularly blood flow-induced wall shear stress, and the localization of atherosclerotic plaques were uncovered, and continuing to fluid shear stress effects on the vascular lining endothelial) cells (ECs), including their effects on EC morphology, biochemical production, and gene expression. The earliest single-gene studies and genome-wide analyses are considered. The final section moves from the ECs lining the vessel wall to the smooth muscle cells and fibroblasts within the wall that are fluid me chanically activated by interstitial flow that imposes shear stresses on their surfaces comparable with those of flowing blood on EC surfaces. Interstitial flow stimulates biochemical production and gene expression, much like blood flow on ECs.

Efficient Coproduction of Mannanase and Cellulase by the Transformation of a Codon-Optimized Endomannanase Gene from Aspergillus niger into Trichoderma reesei.

PubMed

Sun, Xianhua; Xue, Xianli; Li, Mengzhu; Gao, Fei; Hao, Zhenzhen; Huang, Huoqing; Luo, Huiying; Qin, Lina; Yao, Bin; Su, Xiaoyun

2017-12-20

Cellulase and mannanase are both important enzyme additives in animal feeds. Expressing the two enzymes simultaneously within one microbial host could potentially lead to cost reductions in the feeding of animals. For this purpose, we codon-optimized the Aspergillus niger Man5A gene to the codon-usage bias of Trichoderma reesei. By comparing the free energies and the local structures of the nucleotide sequences, one optimized sequence was finally selected and transformed into the T. reesei pyridine-auxotrophic strain TU-6. The codon-optimized gene was expressed to a higher level than the original one. Further expressing the codon-optimized gene in a mutated T. reesei strain through fed-batch cultivation resulted in coproduction of cellulase and mannanase up to 1376 U·mL -1 and 1204 U·mL -1 , respectively.

Impact of Cigarette Smoke on the Human and Mouse Lungs: A Gene-Expression Comparison Study

PubMed Central

Morissette, Mathieu C.; Lamontagne, Maxime; Bérubé, Jean-Christophe; Gaschler, Gordon; Williams, Andrew; Yauk, Carole; Couture, Christian; Laviolette, Michel; Hogg, James C.; Timens, Wim; Halappanavar, Sabina; Stampfli, Martin R.; Bossé, Yohan

2014-01-01

Cigarette smoke is well known for its adverse effects on human health, especially on the lungs. Basic research is essential to identify the mechanisms involved in the development of cigarette smoke-related diseases, but translation of new findings from pre-clinical models to the clinic remains difficult. In the present study, we aimed at comparing the gene expression signature between the lungs of human smokers and mice exposed to cigarette smoke to identify the similarities and differences. Using human and mouse whole-genome gene expression arrays, changes in gene expression, signaling pathways and biological functions were assessed. We found that genes significantly modulated by cigarette smoke in humans were enriched for genes modulated by cigarette smoke in mice, suggesting a similar response of both species. Sixteen smoking-induced genes were in common between humans and mice including six newly reported to be modulated by cigarette smoke. In addition, we identified a new conserved pulmonary response to cigarette smoke in the induction of phospholipid metabolism/degradation pathways. Finally, the majority of biological functions modulated by cigarette smoke in humans were also affected in mice. Altogether, the present study provides information on similarities and differences in lung gene expression response to cigarette smoke that exist between human and mouse. Our results foster the idea that animal models should be used to study the involvement of pathways rather than single genes in human diseases. PMID:24663285

Stability-driven nonnegative matrix factorization to interpret spatial gene expression and build local gene networks.

PubMed

Wu, Siqi; Joseph, Antony; Hammonds, Ann S; Celniker, Susan E; Yu, Bin; Frise, Erwin

2016-04-19

Spatial gene expression patterns enable the detection of local covariability and are extremely useful for identifying local gene interactions during normal development. The abundance of spatial expression data in recent years has led to the modeling and analysis of regulatory networks. The inherent complexity of such data makes it a challenge to extract biological information. We developed staNMF, a method that combines a scalable implementation of nonnegative matrix factorization (NMF) with a new stability-driven model selection criterion. When applied to a set ofDrosophilaearly embryonic spatial gene expression images, one of the largest datasets of its kind, staNMF identified 21 principal patterns (PP). Providing a compact yet biologically interpretable representation ofDrosophilaexpression patterns, PP are comparable to a fate map generated experimentally by laser ablation and show exceptional promise as a data-driven alternative to manual annotations. Our analysis mapped genes to cell-fate programs and assigned putative biological roles to uncharacterized genes. Finally, we used the PP to generate local transcription factor regulatory networks. Spatially local correlation networks were constructed for six PP that span along the embryonic anterior-posterior axis. Using a two-tail 5% cutoff on correlation, we reproduced 10 of the 11 links in the well-studied gap gene network. The performance of PP with theDrosophiladata suggests that staNMF provides informative decompositions and constitutes a useful computational lens through which to extract biological insight from complex and often noisy gene expression data.

Simulation Modeling to Compare High-Throughput, Low-Iteration Optimization Strategies for Metabolic Engineering

PubMed Central

Heinsch, Stephen C.; Das, Siba R.; Smanski, Michael J.

2018-01-01

Increasing the final titer of a multi-gene metabolic pathway can be viewed as a multivariate optimization problem. While numerous multivariate optimization algorithms exist, few are specifically designed to accommodate the constraints posed by genetic engineering workflows. We present a strategy for optimizing expression levels across an arbitrary number of genes that requires few design-build-test iterations. We compare the performance of several optimization algorithms on a series of simulated expression landscapes. We show that optimal experimental design parameters depend on the degree of landscape ruggedness. This work provides a theoretical framework for designing and executing numerical optimization on multi-gene systems. PMID:29535690

Both positive and negative regulatory elements mediate expression of a photoregulated CAB gene from Nicotiana plumbaginifolia.

PubMed Central

Castresana, C; Garcia-Luque, I; Alonso, E; Malik, V S; Cashmore, A R

1988-01-01

We have analyzed promoter regulatory elements from a photoregulated CAB gene (Cab-E) isolated from Nicotiana plumbaginifolia. These studies have been performed by introducing chimeric gene constructs into tobacco cells via Agrobacterium tumefaciens-mediated transformation. Expression studies on the regenerated transgenic plants have allowed us to characterize three positive and one negative cis-acting elements that influence photoregulated expression of the Cab-E gene. Within the upstream sequences we have identified two positive regulatory elements (PRE1 and PRE2) which confer maximum levels of photoregulated expression. These sequences contain multiple repeated elements related to the sequence-ACCGGCCCACTT-. We have also identified within the upstream region a negative regulatory element (NRE) extremely rich in AT sequences, which reduces the level of gene expression in the light. We have defined a light regulatory element (LRE) within the promoter region extending from -396 to -186 bp which confers photoregulated expression when fused to a constitutive nopaline synthase ('nos') promoter. Within this region there is a 132-bp element, extending from -368 to -234 bp, which on deletion from the Cab-E promoter reduces gene expression from high levels to undetectable levels. Finally, we have demonstrated for a full length Cab-E promoter conferring high levels of photoregulated expression, that sequences proximal to the Cab-E TATA box are not replaceable by corresponding sequences from a 'nos' promoter. This contrasts with the apparent equivalence of these Cab-E and 'nos' TATA box-proximal sequences in truncated promoters conferring low levels of photoregulated expression. Images PMID:2901343

Time-Course Gene Set Analysis for Longitudinal Gene Expression Data

PubMed Central

Hejblum, Boris P.; Skinner, Jason; Thiébaut, Rodolphe

2015-01-01

Gene set analysis methods, which consider predefined groups of genes in the analysis of genomic data, have been successfully applied for analyzing gene expression data in cross-sectional studies. The time-course gene set analysis (TcGSA) introduced here is an extension of gene set analysis to longitudinal data. The proposed method relies on random effects modeling with maximum likelihood estimates. It allows to use all available repeated measurements while dealing with unbalanced data due to missing at random (MAR) measurements. TcGSA is a hypothesis driven method that identifies a priori defined gene sets with significant expression variations over time, taking into account the potential heterogeneity of expression within gene sets. When biological conditions are compared, the method indicates if the time patterns of gene sets significantly differ according to these conditions. The interest of the method is illustrated by its application to two real life datasets: an HIV therapeutic vaccine trial (DALIA-1 trial), and data from a recent study on influenza and pneumococcal vaccines. In the DALIA-1 trial TcGSA revealed a significant change in gene expression over time within 69 gene sets during vaccination, while a standard univariate individual gene analysis corrected for multiple testing as well as a standard a Gene Set Enrichment Analysis (GSEA) for time series both failed to detect any significant pattern change over time. When applied to the second illustrative data set, TcGSA allowed the identification of 4 gene sets finally found to be linked with the influenza vaccine too although they were found to be associated to the pneumococcal vaccine only in previous analyses. In our simulation study TcGSA exhibits good statistical properties, and an increased power compared to other approaches for analyzing time-course expression patterns of gene sets. The method is made available for the community through an R package. PMID:26111374

Prediction of Human Disease Genes by Human-Mouse Conserved Coexpression Analysis

PubMed Central

Grassi, Elena; Damasco, Christian; Silengo, Lorenzo; Oti, Martin; Provero, Paolo; Di Cunto, Ferdinando

2008-01-01

Background Even in the post-genomic era, the identification of candidate genes within loci associated with human genetic diseases is a very demanding task, because the critical region may typically contain hundreds of positional candidates. Since genes implicated in similar phenotypes tend to share very similar expression profiles, high throughput gene expression data may represent a very important resource to identify the best candidates for sequencing. However, so far, gene coexpression has not been used very successfully to prioritize positional candidates. Methodology/Principal Findings We show that it is possible to reliably identify disease-relevant relationships among genes from massive microarray datasets by concentrating only on genes sharing similar expression profiles in both human and mouse. Moreover, we show systematically that the integration of human-mouse conserved coexpression with a phenotype similarity map allows the efficient identification of disease genes in large genomic regions. Finally, using this approach on 850 OMIM loci characterized by an unknown molecular basis, we propose high-probability candidates for 81 genetic diseases. Conclusion Our results demonstrate that conserved coexpression, even at the human-mouse phylogenetic distance, represents a very strong criterion to predict disease-relevant relationships among human genes. PMID:18369433

Transcriptome analysis of salinity stress responses in common wheat using a 22k oligo-DNA microarray.

PubMed

Kawaura, Kanako; Mochida, Keiichi; Yamazaki, Yukiko; Ogihara, Yasunari

2006-04-01

In this study, we constructed a 22k wheat oligo-DNA microarray. A total of 148,676 expressed sequence tags of common wheat were collected from the database of the Wheat Genomics Consortium of Japan. These were grouped into 34,064 contigs, which were then used to design an oligonucleotide DNA microarray. Following a multistep selection of the sense strand, 21,939 60-mer oligo-DNA probes were selected for attachment on the microarray slide. This 22k oligo-DNA microarray was used to examine the transcriptional response of wheat to salt stress. More than 95% of the probes gave reproducible hybridization signals when targeted with RNAs extracted from salt-treated wheat shoots and roots. With the microarray, we identified 1,811 genes whose expressions changed more than 2-fold in response to salt. These included genes known to mediate response to salt, as well as unknown genes, and they were classified into 12 major groups by hierarchical clustering. These gene expression patterns were also confirmed by real-time reverse transcription-PCR. Many of the genes with unknown function were clustered together with genes known to be involved in response to salt stress. Thus, analysis of gene expression patterns combined with gene ontology should help identify the function of the unknown genes. Also, functional analysis of these wheat genes should provide new insight into the response to salt stress. Finally, these results indicate that the 22k oligo-DNA microarray is a reliable method for monitoring global gene expression patterns in wheat.

Integrated analysis of HPV-mediated immune alterations in cervical cancer.

PubMed

Chen, Long; Luan, Shaohong; Xia, Baoguo; Liu, Yansheng; Gao, Yuan; Yu, Hongyan; Mu, Qingling; Zhang, Ping; Zhang, Weina; Zhang, Shengmiao; Wei, Guopeng; Yang, Min; Li, Ke

2018-05-01

Human papillomavirus (HPV) infection is the primary cause of cervical cancer. HPV-mediated immune alterations are known to play crucial roles in determining viral persistence and host cell transformation. We sought to thoroughly understand HPV-directed immune alterations in cervical cancer by exploring publically available datasets. 130 HPV positive and 7 HPV negative cervical cancer cases from The Cancer Genome Atlas were compared for differences in gene expression levels and functional enrichment. Analyses for copy number variation (CNV) and genetic mutation were conducted for differentially expressed immune genes. Kaplan-Meier analysis was performed to assess survival and relapse differences across cases with or without alterations of the identified immune signature genes. Genes up-regulated in HPV positive cervical cancer were enriched for various gene ontology terms of immune processes (P=1.05E-14~1.00E-05). Integrated analysis of the differentially expressed immune genes identified 9 genes that displayed either CNV, genetic mutation and/or gene expression changes in at least 10% of the cases of HPV positive cervical cancer. Genomic amplification may cause elevated levels of these genes in some HPV positive cases. Finally, patients with alterations in at least one of the nine signature genes overall had earlier relapse compared to those without any alterations. The altered expression of either TFRC or MMP13 may indicate poor survival for a subset of cervical cancer patients (P=1.07E-07). We identified a novel immune gene signature for HPV positive cervical cancer that is potentially associated with early relapse of cervical cancer. Copyright © 2018. Published by Elsevier Inc.

Uncovering the Role of RNA-Binding Proteins in Gene Expression in the Immune System.

PubMed

Díaz-Muñoz, Manuel D; Turner, Martin

2018-01-01

Fighting external pathogens requires an ever-changing immune system that relies on tight regulation of gene expression. Transcriptional control is the first step to build efficient responses while preventing immunodeficiencies and autoimmunity. Post-transcriptional regulation of RNA editing, location, stability, and translation are the other key steps for final gene expression, and they are all controlled by RNA-binding proteins (RBPs). Nowadays we have a deep understanding of how transcription factors control the immune system but recent evidences suggest that post-transcriptional regulation by RBPs is equally important for both development and activation of immune responses. Here, we review current knowledge about how post-transcriptional control by RBPs shapes our immune system and discuss the perspective of RBPs being the key players of a hidden immune cell epitranscriptome.

Abscisic Acid (ABA) Regulation of Arabidopsis SR Protein Gene Expression

PubMed Central

Cruz, Tiago M. D.; Carvalho, Raquel F.; Richardson, Dale N.; Duque, Paula

2014-01-01

Serine/arginine-rich (SR) proteins are major modulators of alternative splicing, a key generator of proteomic diversity and flexible means of regulating gene expression likely to be crucial in plant environmental responses. Indeed, mounting evidence implicates splicing factors in signal transduction of the abscisic acid (ABA) phytohormone, which plays pivotal roles in the response to various abiotic stresses. Using real-time RT-qPCR, we analyzed total steady-state transcript levels of the 18 SR and two SR-like genes from Arabidopsis thaliana in seedlings treated with ABA and in genetic backgrounds with altered expression of the ABA-biosynthesis ABA2 and the ABA-signaling ABI1 and ABI4 genes. We also searched for ABA-responsive cis elements in the upstream regions of the 20 genes. We found that members of the plant-specific SC35-Like (SCL) Arabidopsis SR protein subfamily are distinctively responsive to exogenous ABA, while the expression of seven SR and SR-related genes is affected by alterations in key components of the ABA pathway. Finally, despite pervasiveness of established ABA-responsive promoter elements in Arabidopsis SR and SR-like genes, their expression is likely governed by additional, yet unidentified cis-acting elements. Overall, this study pinpoints SR34, SR34b, SCL30a, SCL28, SCL33, RS40, SR45 and SR45a as promising candidates for involvement in ABA-mediated stress responses. PMID:25268622

A Green-Light-Responsive System for the Control of Transgene Expression in Mammalian and Plant Cells.

PubMed

Chatelle, Claire; Ochoa-Fernandez, Rocio; Engesser, Raphael; Schneider, Nils; Beyer, Hannes M; Jones, Alex R; Timmer, Jens; Zurbriggen, Matias D; Weber, Wilfried

2018-05-18

The ever-increasing complexity of synthetic gene networks and applications of synthetic biology requires precise and orthogonal gene expression systems. Of particular interest are systems responsive to light as they enable the control of gene expression dynamics with unprecedented resolution in space and time. While broadly used in mammalian backgrounds, however, optogenetic approaches in plant cells are still limited due to interference of the activating light with endogenous photoreceptors. Here, we describe the development of the first synthetic light-responsive system for the targeted control of gene expression in mammalian and plant cells that responds to the green range of the light spectrum in which plant photoreceptors have minimal activity. We first engineered a system based on the light-sensitive bacterial transcription factor CarH and its cognate DNA operator sequence CarO from Thermus thermophilus to control gene expression in mammalian cells. The system was functional in various mammalian cell lines, showing high induction (up to 350-fold) along with low leakiness, as well as high reversibility. We quantitatively described the systems characteristics by the development and experimental validation of a mathematical model. Finally, we transferred the system into A. thaliana protoplasts and demonstrated gene repression in response to green light. We expect that this system will provide new opportunities in applications based on synthetic gene networks and will open up perspectives for optogenetic studies in mammalian and plant cells.

Effects of impurities in biodiesel-derived glycerol on growth and expression of heavy metal ion homeostasis genes and gene products in Pseudomonas putida LS46.

PubMed

Fu, Jilagamazhi; Sharma, Parveen; Spicer, Vic; Krokhin, Oleg V; Zhang, Xiangli; Fristensky, Brian; Wilkins, John A; Cicek, Nazim; Sparling, Richard; Levin, David B

2015-07-01

Biodiesel production-derived waste glycerol (WG) was previously investigated as potential carbon source for medium chain length polyhydroxyalkanoate (mcl-PHA) production by Pseudomonas putida LS46. In this study, we evaluated the effect of impurities in the WG on P. putida LS46 physiology during exponential growth and corresponding changes in transcription and protein expression profiles compared with cells grown on pure, reagent grade glycerol. High concentration of metal ions, such as Na(+), and numbers of heavy metals ion, such as copper, ion, zinc, were detected in biodiesel-derived WG. Omics analysis from the corresponding cultures suggested altered expression of genes involved in transport and metabolism of ammonia and heavy metal ions. Expression of three groups of heavy metal homeostasis genes was significantly changed (mostly upregulated) in WG cultures and included the following: copper-responded cluster 1 and 2 genes, primarily containing cusABC; two copies of copAB and heavy metal translocating P-type ATPase; Fur-regulated, TonB-dependent siderophore receptor; and several cobalt/zinc/cadmium transporters. Expression of these genes suggests regulation of intracellular concentrations of heavy metals during growth on biodiesel-derived glycerol. Finally, a number of genes involved in adapting to, or metabolizing free fatty acids and other nonheavy metal contaminants, such as Na(+), were also upregulated in P. putida LS46 grown on biodiesel-derived glycerol.

Mapping the Shh long-range regulatory domain

PubMed Central

Anderson, Eve; Devenney, Paul S.; Hill, Robert E.; Lettice, Laura A.

2014-01-01

Coordinated gene expression controlled by long-distance enhancers is orchestrated by DNA regulatory sequences involving transcription factors and layers of control mechanisms. The Shh gene and well-established regulators are an example of genomic composition in which enhancers reside in a large desert extending into neighbouring genes to control the spatiotemporal pattern of expression. Exploiting the local hopping activity of the Sleeping Beauty transposon, the lacZ reporter gene was dispersed throughout the Shh region to systematically map the genomic features responsible for expression activity. We found that enhancer activities are retained inside a genomic region that corresponds to the topological associated domain (TAD) defined by Hi-C. This domain of approximately 900 kb is in an open conformation over its length and is generally susceptible to all Shh enhancers. Similar to the distal enhancers, an enhancer residing within the Shh second intron activates the reporter gene located at distances of hundreds of kilobases away, suggesting that both proximal and distal enhancers have the capacity to survey the Shh topological domain to recognise potential promoters. The widely expressed Rnf32 gene lying within the Shh domain evades enhancer activities by a process that may be common among other housekeeping genes that reside in large regulatory domains. Finally, the boundaries of the Shh TAD do not represent the absolute expression limits of enhancer activity, as expression activity is lost stepwise at a number of genomic positions at the verges of these domains. PMID:25252942

Unexplored Potentials of Epigenetic Mechanisms of Plants and Animals—Theoretical Considerations

PubMed Central

Seffer, Istvan; Nemeth, Zoltan; Hoffmann, Gyula; Matics, Robert; Seffer, A Gergely; Koller, Akos

2013-01-01

Morphological and functional changes of cells are important for adapting to environmental changes and associated with continuous regulation of gene expressions. Genes are regulated–in part–by epigenetic mechanisms resulting in alternating patterns of gene expressions throughout life. Epigenetic changes responding to the environmental and intercellular signals can turn on/off specific genes, but do not modify the DNA sequence. Most epigenetic mechanisms are evolutionary conserved in eukaryotic organisms, and several homologs of epigenetic factors are present in plants and animals. Moreover, in vitro studies suggest that the plant cytoplasm is able to induce a nuclear reassembly of the animal cell, whereas others suggest that the ooplasm is able to induce condensation of plant chromatin. Here, we provide an overview of the main epigenetic mechanisms regulating gene expression and discuss fundamental epigenetic mechanisms and factors functioning in both plants and animals. Finally, we hypothesize that animal genome can be reprogrammed by epigenetic factors from the plant protoplast. PMID:25512705

hnRNP L controls HPV16 RNA polyadenylation and splicing in an Akt kinase-dependent manner

PubMed Central

Kajitani, Naoko; Glahder, Jacob; Wu, Chengjun; Yu, Haoran; Nilsson, Kersti

2017-01-01

Abstract Inhibition of the Akt kinase activates HPV16 late gene expression by reducing HPV16 early polyadenylation and by activating HPV16 late L1 mRNA splicing. We identified ‘hot spots’ for RNA binding proteins at the early polyA signal and at splice sites on HPV16 late mRNAs. We observed that hnRNP L was associated with sequences at all HPV16 late splice sites and at the early polyA signal. Akt kinase inhibition resulted in hnRNP L dephosphorylation and reduced association of hnRNP L with HPV16 mRNAs. This was accompanied by an increased binding of U2AF65 and Sam68 to HPV16 mRNAs. Furthermore, siRNA knock-down of hnRNP L or Akt induced HPV16 gene expression. Treatment of HPV16 immortalized keratinocytes with Akt kinase inhibitor reduced hnRNP L binding to HPV16 mRNAs and induced HPV16 L1 mRNA production. Finally, deletion of the hnRNP L binding sites in HPV16 subgenomic expression plasmids resulted in activation of HPV16 late gene expression. In conclusion, the Akt kinase inhibits HPV16 late gene expression at the level of RNA processing by controlling the RNA-binding protein hnRNP L. We speculate that Akt kinase activity upholds an intracellular milieu that favours HPV16 early gene expression and suppresses HPV16 late gene expression. PMID:28934469

Variations in oxygen concentration cause differential antioxidant response and expression of related genes in Beauveria bassiana.

PubMed

Garza-López, Paul Misael; Suárez-Vergel, Gerardo; Hamdan-Partida, Aida; Loera, Octavio

2015-04-01

The entomopathogenic fungus Beauveria bassiana is widely used in pest biocontrol strategies. We evaluated both the antioxidant response mediated by compatible solutes, trehalose or mannitol, and the expression of related genes using oxygen pulses at three oxygen concentrations in solid state culture (SSC): normal atmosphere (21% O2), low oxygen (16% O2) and enriched oxygen (26% O2). Trehalose concentration decreased 75% after atmospheric modifications in the cultures, whereas mannitol synthesis was three-fold higher under the 16% O2 pulses relative to normal atmosphere (100 and 30 μg mannitol mg(-1) biomass, respectively). Confirming this result, expression of the mpd gene, coding for mannitol-1-P dehydrogenase (MPD), increased up to 1.4 times after O2 pulses. The expression of the bbrgs1 gene, encoding a regulatory G protein related to conidiation, was analysed to explain previously reported differences in conidial production. Surprisingly, expression of bbrgs1 decreased after atmospheric modification. Finally, principal component analysis (PCA) indicated that 83.39% of the variability in the data could be explained by two components. This analysis corroborated the positive correlation between mannitol concentration and mpd gene expression, as well as the negative correlation between conidial production and bbrgs1 gene expression. This study contributes to understanding of antioxidant and molecular response of B. bassiana induced under oxidant conditions. Copyright © 2015 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.

Control of Flagellar Gene Regulation in Legionella pneumophila and Its Relation to Growth Phase▿ †

PubMed Central

Albert-Weissenberger, Christiane; Sahr, Tobias; Sismeiro, Odile; Hacker, Jörg; Heuner, Klaus; Buchrieser, Carmen

2010-01-01

The bacterial pathogen Legionella pneumophila responds to environmental changes by differentiation. At least two forms are well described: replicative bacteria are avirulent; in contrast, transmissive bacteria express virulence traits and flagella. Phenotypic analysis, Western blotting, and electron microscopy of mutants of the regulatory genes encoding RpoN, FleQ, FleR, and FliA demonstrated that flagellin expression is strongly repressed and that the mutants are nonflagellated in the transmissive phase. Transcriptome analyses elucidated that RpoN, together with FleQ, enhances transcription of 14 out of 31 flagellar class II genes, which code for the basal body, hook, and regulatory proteins. Unexpectedly, FleQ independent of RpoN enhances the transcription of fliA encoding sigma 28. Expression analysis of a fliA mutant showed that FliA activates three out of the five remaining flagellar class III genes and the flagellar class IV genes. Surprisingly, FleR does not induce but inhibits expression of at least 14 flagellar class III genes on the transcriptional level. Thus, we propose that flagellar class II genes are controlled by FleQ and RpoN, whereas the transcription of the class III gene fliA is controlled in a FleQ-dependent but RpoN-independent manner. However, RpoN and FleR might influence flagellin synthesis on a posttranscriptional level. In contrast to the commonly accepted view that enhancer-binding proteins such as FleQ always interact with RpoN to fullfill their regulatory functions, our results strongly indicate that FleQ regulates gene expression that is RpoN dependent and RpoN independent. Finally, FliA induces expression of flagellar class III and IV genes leading to the complete synthesis of the flagellum. PMID:19915024

Unique Temporal Expression of Triplicated Long-Wavelength Opsins in Developing Butterfly Eyes

PubMed Central

Arikawa, Kentaro; Iwanaga, Tomoyuki; Wakakuwa, Motohiro; Kinoshita, Michiyo

2017-01-01

Following gene duplication events, the expression patterns of the resulting gene copies can often diverge both spatially and temporally. Here we report on gene duplicates that are expressed in distinct but overlapping patterns, and which exhibit temporally divergent expression. Butterflies have sophisticated color vision and spectrally complex eyes, typically with three types of heterogeneous ommatidia. The eyes of the butterfly Papilio xuthus express two green- and one red-absorbing visual pigment, which came about via gene duplication events, in addition to one ultraviolet (UV)- and one blue-absorbing visual pigment. We localized mRNAs encoding opsins of these visual pigments in developing eye disks throughout the pupal stage. The mRNAs of the UV and blue opsin are expressed early in pupal development (pd), specifying the type of the ommatidium in which they appear. Red sensitive photoreceptors first express a green opsin mRNA, which is replaced later by the red opsin mRNA. Broadband photoreceptors (that coexpress the green and red opsins) first express the green opsin mRNA, later change to red opsin mRNA and finally re-express the green opsin mRNA in addition to the red mRNA. Such a unique temporal and spatial expression pattern of opsin mRNAs may reflect the evolution of visual pigments and provide clues toward understanding how the spectrally complex eyes of butterflies evolved. PMID:29238294

Pgas, a Low-pH-Induced Promoter, as a Tool for Dynamic Control of Gene Expression for Metabolic Engineering of Aspergillus niger.

PubMed

Yin, Xian; Shin, Hyun-Dong; Li, Jianghua; Du, Guocheng; Liu, Long; Chen, Jian

2017-03-15

The dynamic control of gene expression is important for adjusting fluxes in order to obtain desired products and achieve appropriate cell growth, particularly when the synthesis of a desired product drains metabolites required for cell growth. For dynamic gene expression, a promoter responsive to a particular environmental stressor is vital. Here, we report a low-pH-inducible promoter, P gas , which promotes minimal gene expression at pH values above 5.0 but functions efficiently at low pHs, such as pH 2.0. First, we performed a transcriptional analysis of Aspergillus niger , an excellent platform for the production of organic acids, and we found that the promoter P gas may act efficiently at low pH. Then, a gene for synthetic green fluorescent protein ( sGFP ) was successfully expressed by P gas at pH 2.0, verifying the results of the transcriptional analysis. Next, P gas was used to express the cis -aconitate decarboxylase ( cad ) gene of Aspergillus terreus in A. niger , allowing the production of itaconic acid at a titer of 4.92 g/liter. Finally, we found that P gas strength was independent of acid type and acid ion concentration, showing dependence on pH only. IMPORTANCE The promoter P gas can be used for the dynamic control of gene expression in A. niger for metabolic engineering to produce organic acids. This promoter may also be a candidate tool for genetic engineering. Copyright © 2017 American Society for Microbiology.

Still acting green: continued expression of photosynthetic genes in the heterotrophic Dinoflagellate Pfiesteria piscicida (Peridiniales, Alveolata).

PubMed

Kim, Gwang Hoon; Jeong, Hae Jin; Yoo, Yeong Du; Kim, Sunju; Han, Ji Hee; Han, Jong Won; Zuccarello, Giuseppe C

2013-01-01

The loss of photosynthetic function should lead to the cessation of expression and finally loss of photosynthetic genes in the new heterotroph. Dinoflagellates are known to have lost their photosynthetic ability several times. Dinoflagellates have also acquired photosynthesis from other organisms, either on a long-term basis or as "kleptoplastids" multiple times. The fate of photosynthetic gene expression in heterotrophs can be informative into evolution of gene expression patterns after functional loss, and the dinoflagellates ability to acquire new photosynthetic function through additional endosymbiosis. To explore this we analyzed a large-scale EST database consisting of 151,091 unique sequences (29,170 contigs, 120,921 singletons) obtained from 454 pyrosequencing of the heterotrophic dinoflagellate Pfiesteria piscicida. About 597 contigs from P. piscicida showed significant homology (E-value

Hepatic gene expression of Caucasian and African-American patients with obesity-related non-alcoholic fatty liver disease.

PubMed

Stepanova, Maria; Hossain, Noreen; Afendy, Arian; Perry, Kellie; Goodman, Zachary D; Baranova, Ancha; Younossi, Zobair

2010-05-01

There is increasing data suggesting that African Americans with NAFLD tend to have less progressive liver disease. The aim of this study is to assess differences in the hepatic gene expression of African-American and Caucasian patients with NAFLD who had undergone bariatric surgery. A total of 94 patients (81 NAFLD and 13 weight-matched controls with normal liver biopsy) were included. Of the entire cohort, 73 were Caucasians and 21 were African Americans. All patients were undergoing bariatric surgery. Two liver biopsies were obtained at the time of surgery. One biopsy was snap-frozen for gene expression and the other biopsy was stained for pathologic assessment. Liver biopsy confirmed that 24 patients from our cohort had NASH while 57 had only simple steatosis. Snap-frozen liver biopsy specimens of these patients were then used for the RNA extraction. cDNA probes were hybridized with customized microarray gene chips containing 5,220 relevant genes. Gene expression profiles were compared between groups using significance analysis of microarrays algorithm. In comparison to all Caucasian patients, African-American patients had over-expression of EPB41L1, IGF2, FAH, ACSL4, FUT4, CYP3A (q values < 10(-4)). In comparison to Caucasian NAFLD patients, African-American NAFLD patients showed over-expression of EPB41L1 and ACSL4 genes. Finally, in comparison to Caucasian NASH patients, African-American NASH patients showed over-expression of GSTM 2, GSTM4 and GSTM5 as well as FH and ASCL4 genes. Some genes highlighted by this analysis, particularly cytochrome CYP3A and glutathione transferases GSTM2, 4, 5, were previously implicated in the pathogenesis of NASH. African-American patients with biopsy-proven obesity-related NAFLD and NASH have a specific hepatic gene expression pattern that may explain their differences from Caucasian patients with NAFLD in developing progressive liver disease.

Backward-stochastic-differential-equation approach to modeling of gene expression

NASA Astrophysics Data System (ADS)

Shamarova, Evelina; Chertovskih, Roman; Ramos, Alexandre F.; Aguiar, Paulo

2017-03-01

In this article, we introduce a backward method to model stochastic gene expression and protein-level dynamics. The protein amount is regarded as a diffusion process and is described by a backward stochastic differential equation (BSDE). Unlike many other SDE techniques proposed in the literature, the BSDE method is backward in time; that is, instead of initial conditions it requires the specification of end-point ("final") conditions, in addition to the model parametrization. To validate our approach we employ Gillespie's stochastic simulation algorithm (SSA) to generate (forward) benchmark data, according to predefined gene network models. Numerical simulations show that the BSDE method is able to correctly infer the protein-level distributions that preceded a known final condition, obtained originally from the forward SSA. This makes the BSDE method a powerful systems biology tool for time-reversed simulations, allowing, for example, the assessment of the biological conditions (e.g., protein concentrations) that preceded an experimentally measured event of interest (e.g., mitosis, apoptosis, etc.).

Backward-stochastic-differential-equation approach to modeling of gene expression.

PubMed

Shamarova, Evelina; Chertovskih, Roman; Ramos, Alexandre F; Aguiar, Paulo

2017-03-01

In this article, we introduce a backward method to model stochastic gene expression and protein-level dynamics. The protein amount is regarded as a diffusion process and is described by a backward stochastic differential equation (BSDE). Unlike many other SDE techniques proposed in the literature, the BSDE method is backward in time; that is, instead of initial conditions it requires the specification of end-point ("final") conditions, in addition to the model parametrization. To validate our approach we employ Gillespie's stochastic simulation algorithm (SSA) to generate (forward) benchmark data, according to predefined gene network models. Numerical simulations show that the BSDE method is able to correctly infer the protein-level distributions that preceded a known final condition, obtained originally from the forward SSA. This makes the BSDE method a powerful systems biology tool for time-reversed simulations, allowing, for example, the assessment of the biological conditions (e.g., protein concentrations) that preceded an experimentally measured event of interest (e.g., mitosis, apoptosis, etc.).

Angiogenesis-related gene expression analysis in celiac disease.

PubMed

Castellanos-Rubio, Ainara; Caja, Sergio; Irastorza, Iñaki; Fernandez-Jimenez, Nora; Plaza-Izurieta, Leticia; Vitoria, Juan Carlos; Maki, Markku; Lindfors, Katri; Bilbao, Jose Ramon

2012-05-01

Celiac disease (CD) involves disturbance of the small-bowel mucosal vascular network, and transglutaminase autoantibodies (TGA) have been related to angiogenesis disturbance, a complex phenomenon probably also influenced by common genetic variants in angiogenesis-related genes. A set of genes with "angiogenesis" GO term identified in a previous expression microarray experiment (SCG2, STAB1, TGFA, ANG, ERBB2, GNA13, PML, CASP8, ECGF1, JAG1, HIF1A, TNFSF13 and TGM2) was selected for genetic and functional studies. SNPs that showed a trend for association with CD in the first GWAS were genotyped in 555 patients and 541 controls. Gene expression of all genes was quantified in 15 pairs of intestinal biopsies (diagnosis vs. GFD) and in three-dimensional HUVEC and T84 cell cultures incubated with TGA-positive and negative serum. A regulatory SNP in TNFSF13 (rs11552708) is associated with CD (p = 0.01, OR = 0.7). Expression changes in biopsies pointed to TGM2 and PML as up-regulated antiangiogenic genes and to GNA13, TGFA, ERBB2 and SCG2 as down-regulated proangiogenic factors in CD. TGA seem to enhance TGM2 expression in both cell models, but PML expression was induced only in T84 enterocytes while GNA13 and ERBB2 were repressed in HUVEC endothelial cells, with several genes showing discordant effects in each model, highlighting the complexity of gene interactions in the pathogenesis of CD. Finally, cell culture models are useful tools to help dissect complex responses observed in human explants.

Sex Bias and Maternal Contribution to Gene Expression Divergence in Drosophila Blastoderm Embryos

PubMed Central

Paris, Mathilde; Villalta, Jacqueline E.; Eisen, Michael B.; Lott, Susan E.

2015-01-01

Early embryogenesis is a unique developmental stage where genetic control of development is handed off from mother to zygote. Yet the contribution of this transition to the evolution of gene expression is poorly understood. Here we study two aspects of gene expression specific to early embryogenesis in Drosophila: sex-biased gene expression prior to the onset of canonical X chromosomal dosage compensation, and the contribution of maternally supplied mRNAs. We sequenced mRNAs from individual unfertilized eggs and precisely staged and sexed blastoderm embryos, and compared levels between D. melanogaster, D. yakuba, D. pseudoobscura and D. virilis. First, we find that mRNA content is highly conserved for a given stage and that studies relying on pooled embryos likely systematically overstate the degree of gene expression divergence. Unlike studies done on larvae and adults where most species show a larger proportion of genes with male-biased expression, we find that transcripts in Drosophila embryos are largely female-biased in all species, likely due to incomplete dosage compensation prior to the activation of the canonical dosage compensation mechanism. The divergence of sex-biased gene expression across species is observed to be often due to lineage-specific decrease of expression; the most drastic example of which is the overall reduction of male expression from the neo-X chromosome in D. pseudoobscura, leading to a pervasive female-bias on this chromosome. We see no evidence for a faster evolution of expression on the X chromosome in embryos (no “faster-X” effect), unlike in adults, and contrary to a previous study on pooled non-sexed embryos. Finally, we find that most genes are conserved in regard to their maternal or zygotic origin of transcription, and present evidence that differences in maternal contribution to the blastoderm transcript pool may be due to species-specific divergence of transcript degradation rates. PMID:26485701

Genome-Wide Identification and Expression Analysis of the WRKY Gene Family in Cassava

PubMed Central

Wei, Yunxie; Shi, Haitao; Xia, Zhiqiang; Tie, Weiwei; Ding, Zehong; Yan, Yan; Wang, Wenquan; Hu, Wei; Li, Kaimian

2016-01-01

The WRKY family, a large family of transcription factors (TFs) found in higher plants, plays central roles in many aspects of physiological processes and adaption to environment. However, little information is available regarding the WRKY family in cassava (Manihot esculenta). In the present study, 85 WRKY genes were identified from the cassava genome and classified into three groups according to conserved WRKY domains and zinc-finger structure. Conserved motif analysis showed that all of the identified MeWRKYs had the conserved WRKY domain. Gene structure analysis suggested that the number of introns in MeWRKY genes varied from 1 to 5, with the majority of MeWRKY genes containing three exons. Expression profiles of MeWRKY genes in different tissues and in response to drought stress were analyzed using the RNA-seq technique. The results showed that 72 MeWRKY genes had differential expression in their transcript abundance and 78 MeWRKY genes were differentially expressed in response to drought stresses in different accessions, indicating their contribution to plant developmental processes and drought stress resistance in cassava. Finally, the expression of 9 WRKY genes was analyzed by qRT-PCR under osmotic, salt, ABA, H2O2, and cold treatments, indicating that MeWRKYs may be involved in different signaling pathways. Taken together, this systematic analysis identifies some tissue-specific and abiotic stress-responsive candidate MeWRKY genes for further functional assays in planta, and provides a solid foundation for understanding of abiotic stress responses and signal transduction mediated by WRKYs in cassava. PMID:26904033

Genome-Wide Identification and Expression Analysis of the WRKY Gene Family in Cassava.

PubMed

Wei, Yunxie; Shi, Haitao; Xia, Zhiqiang; Tie, Weiwei; Ding, Zehong; Yan, Yan; Wang, Wenquan; Hu, Wei; Li, Kaimian

2016-01-01

The WRKY family, a large family of transcription factors (TFs) found in higher plants, plays central roles in many aspects of physiological processes and adaption to environment. However, little information is available regarding the WRKY family in cassava (Manihot esculenta). In the present study, 85 WRKY genes were identified from the cassava genome and classified into three groups according to conserved WRKY domains and zinc-finger structure. Conserved motif analysis showed that all of the identified MeWRKYs had the conserved WRKY domain. Gene structure analysis suggested that the number of introns in MeWRKY genes varied from 1 to 5, with the majority of MeWRKY genes containing three exons. Expression profiles of MeWRKY genes in different tissues and in response to drought stress were analyzed using the RNA-seq technique. The results showed that 72 MeWRKY genes had differential expression in their transcript abundance and 78 MeWRKY genes were differentially expressed in response to drought stresses in different accessions, indicating their contribution to plant developmental processes and drought stress resistance in cassava. Finally, the expression of 9 WRKY genes was analyzed by qRT-PCR under osmotic, salt, ABA, H2O2, and cold treatments, indicating that MeWRKYs may be involved in different signaling pathways. Taken together, this systematic analysis identifies some tissue-specific and abiotic stress-responsive candidate MeWRKY genes for further functional assays in planta, and provides a solid foundation for understanding of abiotic stress responses and signal transduction mediated by WRKYs in cassava.

Survey of the Heritability and Sparse Architecture of Gene Expression Traits across Human Tissues.

PubMed

Wheeler, Heather E; Shah, Kaanan P; Brenner, Jonathon; Garcia, Tzintzuni; Aquino-Michaels, Keston; Cox, Nancy J; Nicolae, Dan L; Im, Hae Kyung

2016-11-01

Understanding the genetic architecture of gene expression traits is key to elucidating the underlying mechanisms of complex traits. Here, for the first time, we perform a systematic survey of the heritability and the distribution of effect sizes across all representative tissues in the human body. We find that local h2 can be relatively well characterized with 59% of expressed genes showing significant h2 (FDR < 0.1) in the DGN whole blood cohort. However, current sample sizes (n ≤ 922) do not allow us to compute distal h2. Bayesian Sparse Linear Mixed Model (BSLMM) analysis provides strong evidence that the genetic contribution to local expression traits is dominated by a handful of genetic variants rather than by the collective contribution of a large number of variants each of modest size. In other words, the local architecture of gene expression traits is sparse rather than polygenic across all 40 tissues (from DGN and GTEx) examined. This result is confirmed by the sparsity of optimal performing gene expression predictors via elastic net modeling. To further explore the tissue context specificity, we decompose the expression traits into cross-tissue and tissue-specific components using a novel Orthogonal Tissue Decomposition (OTD) approach. Through a series of simulations we show that the cross-tissue and tissue-specific components are identifiable via OTD. Heritability and sparsity estimates of these derived expression phenotypes show similar characteristics to the original traits. Consistent properties relative to prior GTEx multi-tissue analysis results suggest that these traits reflect the expected biology. Finally, we apply this knowledge to develop prediction models of gene expression traits for all tissues. The prediction models, heritability, and prediction performance R2 for original and decomposed expression phenotypes are made publicly available (https://github.com/hakyimlab/PrediXcan).

A Gene-Oriented Haplotype Comparison Reveals Recently Selected Genomic Regions in Temperate and Tropical Maize Germplasm

PubMed Central

Zhang, Jie; Li, Yongxiang; Zheng, Jun; Zhang, Hongwei; Yang, Xiaohong; Wang, Jianhua; Wang, Guoying

2017-01-01

The extensive genetic variation present in maize (Zea mays) germplasm makes it possible to detect signatures of positive artificial selection that occurred during temperate and tropical maize improvement. Here we report an analysis of 532,815 polymorphisms from a maize association panel consisting of 368 diverse temperate and tropical inbred lines. We developed a gene-oriented approach adapting exonic polymorphisms to identify recently selected alleles by comparing haplotypes across the maize genome. This analysis revealed evidence of selection for more than 1100 genomic regions during recent improvement, and included regulatory genes and key genes with visible mutant phenotypes. We find that selected candidate target genes in temperate maize are enriched in biosynthetic processes, and further examination of these candidates highlights two cases, sucrose flux and oil storage, in which multiple genes in a common pathway can be cooperatively selected. Finally, based on available parallel gene expression data, we hypothesize that some genes were selected for regulatory variations, resulting in altered gene expression. PMID:28099470

Identification of nuclear genes controlling chlorophyll synthesis in barley by RNA-seq.

PubMed

Shmakov, Nickolay A; Vasiliev, Gennadiy V; Shatskaya, Natalya V; Doroshkov, Alexey V; Gordeeva, Elena I; Afonnikov, Dmitry A; Khlestkina, Elena K

2016-11-16

Albinism in plants is characterized by lack of chlorophyll and results in photosynthesis impairment, abnormal plant development and premature death. These abnormalities are frequently encountered in interspecific crosses and tissue culture experiments. Analysis of albino mutant phenotypes with full or partial chlorophyll deficiency can shed light on genetic determinants and molecular mechanisms of albinism. Here we report analysis of RNA-seq transcription profiling of barley (Hordeum vulgare L.) near-isogenic lines, one of which is a carrier of mutant allele of the Alm gene for albino lemma and pericarp phenotype (line i:BwAlm). 1221 genome fragments have statistically significant changes in expression levels between lines i:BwAlm and Bowman, with 148 fragments having increased expression levels in line i:BwAlm, and 1073 genome fragments, including 42 plastid operons, having decreased levels of expression in line i:BwAlm. We detected functional dissimilarity between genes with higher and lower levels of expression in i:BwAlm line. Genes with lower level of expression in the i:BwAlm line are mostly associated with photosynthesis and chlorophyll synthesis, while genes with higher expression level are functionally associated with vesicle transport. Differentially expressed genes are shown to be involved in several metabolic pathways; the largest fraction of such genes was observed for the Calvin-Benson-Bassham cycle. Finally, de novo assembly of transcriptome contains several transcripts, not annotated in current H. vulgare genome version. Our results provide the new information about genes which could be involved in formation of albino lemma and pericarp phenotype. They demonstrate the interplay between nuclear and chloroplast genomes in this physiological process.

Low-grade and high-grade mammary carcinomas in WAP-T transgenic mice are independent entities distinguished by Met expression.

PubMed

Otto, Benjamin; Gruner, Katharina; Heinlein, Christina; Wegwitz, Florian; Nollau, Peter; Ylstra, Bauke; Pantel, Klaus; Schumacher, Udo; Baumbusch, Lars O; Martin-Subero, José Ignacio; Siebert, Reiner; Wagener, Christoph; Streichert, Thomas; Deppert, Wolfgang; Tolstonog, Genrich V

2013-03-15

Mammary carcinomas developing in SV40 transgenic WAP-T mice arise in two distinct histological phenotypes: as differentiated low-grade and undifferentiated high-grade tumors. We integrated different types of information such as histological grading, analysis of aCGH-based gene copy number and gene expression profiling to provide a comprehensive molecular description of mammary tumors in WAP-T mice. Applying a novel procedure for the correlation of gene copy number with gene expression on a global scale, we observed in tumor samples a global coherence between genotype and transcription. This coherence can be interpreted as a matched transcriptional regulation inherited from the cells of tumor origin and determined by the activity of cancer driver genes. Despite common recurrent genomic aberrations, e.g. gain of chr. 15 in most WAP-T tumors, loss of chr. 19 frequently occurs only in low-grade tumors. These tumors show features of "basal-like" epithelial differentiation, particularly expression of keratin 14. The high-grade tumors are clearly separated from the low-grade tumors by strong expression of the Met gene and by coexpression of epithelial (e.g. keratin 18) and mesenchymal (e.g. vimentin) markers. In high-grade tumors, the expression of the nonmutated Met protein is associated with Met-locus amplification and Met activity. The role of Met as a cancer driver gene is supported by the contribution of active Met signaling to motility and growth of mammary tumor-derived cells. Finally, we discuss the independent origin of low- and high-grade tumors from distinct cells of tumor origin, possibly luminal progenitors, distinguished by Met gene expression and Met signaling. Copyright © 2012 UICC.

Genome-wide transcriptome and expression profile analysis of Phalaenopsis during explant browning.

PubMed

Xu, Chuanjun; Zeng, Biyu; Huang, Junmei; Huang, Wen; Liu, Yumei

2015-01-01

Explant browning presents a major problem for in vitro culture, and can lead to the death of the explant and failure of regeneration. Considerable work has examined the physiological mechanisms underlying Phalaenopsis leaf explant browning, but the molecular mechanisms of browning remain elusive. In this study, we used whole genome RNA sequencing to examine Phalaenopsis leaf explant browning at genome-wide level. We first used Illumina high-throughput technology to sequence the transcriptome of Phalaenopsis and then performed de novo transcriptome assembly. We assembled 79,434,350 clean reads into 31,708 isogenes and generated 26,565 annotated unigenes. We assigned Gene Ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations, and potential Pfam domains to each transcript. Using the transcriptome data as a reference, we next analyzed the differential gene expression of explants cultured for 0, 3, and 6 d, respectively. We then identified differentially expressed genes (DEGs) before and after Phalaenopsis explant browning. We also performed GO, KEGG functional enrichment and Pfam analysis of all DEGs. Finally, we selected 11 genes for quantitative real-time PCR (qPCR) analysis to confirm the expression profile analysis. Here, we report the first comprehensive analysis of transcriptome and expression profiles during Phalaenopsis explant browning. Our results suggest that Phalaenopsis explant browning may be due in part to gene expression changes that affect the secondary metabolism, such as: phenylpropanoid pathway and flavonoid biosynthesis. Genes involved in photosynthesis and ATPase activity have been found to be changed at transcription level; these changes may perturb energy metabolism and thus lead to the decay of plant cells and tissues. This study provides comprehensive gene expression data for Phalaenopsis browning. Our data constitute an important resource for further functional studies to prevent explant browning.

Genome-Wide Transcriptome and Expression Profile Analysis of Phalaenopsis during Explant Browning

PubMed Central

Xu, Chuanjun; Zeng, Biyu; Huang, Junmei; Huang, Wen; Liu, Yumei

2015-01-01

Background Explant browning presents a major problem for in vitro culture, and can lead to the death of the explant and failure of regeneration. Considerable work has examined the physiological mechanisms underlying Phalaenopsis leaf explant browning, but the molecular mechanisms of browning remain elusive. In this study, we used whole genome RNA sequencing to examine Phalaenopsis leaf explant browning at genome-wide level. Methodology/Principal Findings We first used Illumina high-throughput technology to sequence the transcriptome of Phalaenopsis and then performed de novo transcriptome assembly. We assembled 79,434,350 clean reads into 31,708 isogenes and generated 26,565 annotated unigenes. We assigned Gene Ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) annotations, and potential Pfam domains to each transcript. Using the transcriptome data as a reference, we next analyzed the differential gene expression of explants cultured for 0, 3, and 6 d, respectively. We then identified differentially expressed genes (DEGs) before and after Phalaenopsis explant browning. We also performed GO, KEGG functional enrichment and Pfam analysis of all DEGs. Finally, we selected 11 genes for quantitative real-time PCR (qPCR) analysis to confirm the expression profile analysis. Conclusions/Significance Here, we report the first comprehensive analysis of transcriptome and expression profiles during Phalaenopsis explant browning. Our results suggest that Phalaenopsis explant browning may be due in part to gene expression changes that affect the secondary metabolism, such as: phenylpropanoid pathway and flavonoid biosynthesis. Genes involved in photosynthesis and ATPase activity have been found to be changed at transcription level; these changes may perturb energy metabolism and thus lead to the decay of plant cells and tissues. This study provides comprehensive gene expression data for Phalaenopsis browning. Our data constitute an important resource for further functional studies to prevent explant browning. PMID:25874455

SigEMD: A powerful method for differential gene expression analysis in single-cell RNA sequencing data.

PubMed

Wang, Tianyu; Nabavi, Sheida

2018-04-24

Differential gene expression analysis is one of the significant efforts in single cell RNA sequencing (scRNAseq) analysis to discover the specific changes in expression levels of individual cell types. Since scRNAseq exhibits multimodality, large amounts of zero counts, and sparsity, it is different from the traditional bulk RNA sequencing (RNAseq) data. The new challenges of scRNAseq data promote the development of new methods for identifying differentially expressed (DE) genes. In this study, we proposed a new method, SigEMD, that combines a data imputation approach, a logistic regression model and a nonparametric method based on the Earth Mover's Distance, to precisely and efficiently identify DE genes in scRNAseq data. The regression model and data imputation are used to reduce the impact of large amounts of zero counts, and the nonparametric method is used to improve the sensitivity of detecting DE genes from multimodal scRNAseq data. By additionally employing gene interaction network information to adjust the final states of DE genes, we further reduce the false positives of calling DE genes. We used simulated datasets and real datasets to evaluate the detection accuracy of the proposed method and to compare its performance with those of other differential expression analysis methods. Results indicate that the proposed method has an overall powerful performance in terms of precision in detection, sensitivity, and specificity. Copyright © 2018 Elsevier Inc. All rights reserved.

Interleukin-1β modulates smooth muscle cell phenotype to a distinct inflammatory state relative to PDGF-DD via NF-κB-dependent mechanisms.

PubMed

Alexander, Matthew R; Murgai, Meera; Moehle, Christopher W; Owens, Gary K

2012-04-02

Smooth muscle cell (SMC) phenotypic modulation in atherosclerosis and in response to PDGF in vitro involves repression of differentiation marker genes and increases in SMC proliferation, migration, and matrix synthesis. However, SMCs within atherosclerotic plaques can also express a number of proinflammatory genes, and in cultured SMCs the inflammatory cytokine IL-1β represses SMC marker gene expression and induces inflammatory gene expression. Studies herein tested the hypothesis that IL-1β modulates SMC phenotype to a distinct inflammatory state relative to PDGF-DD. Genome-wide gene expression analysis of IL-1β- or PDGF-DD-treated SMCs revealed that although both stimuli repressed SMC differentiation marker gene expression, IL-1β distinctly induced expression of proinflammatory genes, while PDGF-DD primarily induced genes involved in cell proliferation. Promoters of inflammatory genes distinctly induced by IL-1β exhibited over-representation of NF-κB binding sites, and NF-κB inhibition in SMCs reduced IL-1β-induced upregulation of proinflammatory genes as well as repression of SMC differentiation marker genes. Interestingly, PDGF-DD-induced SMC marker gene repression was not NF-κB dependent. Finally, immunofluorescent staining of mouse atherosclerotic lesions revealed the presence of cells positive for the marker of an IL-1β-stimulated inflammatory SMC, chemokine (C-C motif) ligand 20 (CCL20), but not the PDGF-DD-induced gene, regulator of G protein signaling 17 (RGS17). Results demonstrate that IL-1β- but not PDGF-DD-induced phenotypic modulation of SMC is characterized by NF-κB-dependent activation of proinflammatory genes, suggesting the existence of a distinct inflammatory SMC phenotype. In addition, studies provide evidence for the possible utility of CCL20 and RGS17 as markers of inflammatory and proliferative state SMCs within atherosclerotic plaques in vivo.

Structural and Biochemical Characterization of a Novel Aminopeptidase from Human Intestine

DOE PAGES

Tykvart, Jan; Bařinka, Cyril; Svoboda, Michal; ...

2015-03-09

N-acetylated α-linked acidic dipeptidase-like protein (NAALADase L), encoded by the NAALADL1 gene, is a close homolog of glutamate carboxypeptidase II, a metallopeptidase that has been intensively studied as a target for imaging and therapy of solid malignancies and neuropathologies. However, neither the physiological functions nor structural features of NAALADase L are known at present. In this paper, we report a thorough characterization of the protein product of the human NAALADL1 gene, including heterologous overexpression and purification, structural and biochemical characterization, and analysis of its expression profile. By solving the NAALADase L x-ray structure, we provide the first experimental evidence thatmore » it is a zinc-dependent metallopeptidase with a catalytic mechanism similar to that of glutamate carboxypeptidase II yet distinct substrate specificity. A proteome-based assay revealed that the NAALADL1 gene product possesses previously unrecognized aminopeptidase activity but no carboxy- or endopeptidase activity. These findings were corroborated by site-directed mutagenesis and identification of bestatin as a potent inhibitor of the enzyme. Analysis of NAALADL1 gene expression at both the mRNA and protein levels revealed the small intestine as the major site of protein expression and points toward extensive alternative splicing of the NAALADL1 gene transcript. Taken together, our data imply that the NAALADL1 gene product's primary physiological function is associated with the final stages of protein/peptide digestion and absorption in the human digestive system. Finally, based on these results, we suggest a new name for this enzyme: human ileal aminopeptidase (HILAP).« less

Serotype-dependent transduction efficiencies of recombinant adeno-associated viral vectors in monkey neocortex

PubMed Central

Gerits, Annelies; Vancraeyenest, Pascaline; Vreysen, Samme; Laramée, Marie-Eve; Michiels, Annelies; Gijsbers, Rik; Van den Haute, Chris; Moons, Lieve; Debyser, Zeger; Baekelandt, Veerle; Arckens, Lutgarde; Vanduffel, Wim

2015-01-01

Abstract. Viral vector-mediated expression of genes (e.g., coding for opsins and designer receptors) has grown increasingly popular. Cell-type specific expression is achieved by altering viral vector tropism through crosspackaging or by cell-specific promoters driving gene expression. Detailed information about transduction properties of most recombinant adeno-associated viral vector (rAAV) serotypes in macaque cortex is gradually becoming available. Here, we compare transduction efficiencies and expression patterns of reporter genes in two macaque neocortical areas employing different rAAV serotypes and promoters. A short version of the calmodulin-kinase-II (CaMKIIα0.4) promoter resulted in reporter gene expression in cortical neurons for all tested rAAVs, albeit with different efficiencies for spread: rAAV2/5>>rAAV2/7>rAAV2/8>rAAV2/9>>rAAV2/1 and proportion of transduced cells: rAAV2/1>rAAV2/5>rAAV2/7=rAAV2/9>rAAV2/8. In contrast to rodent studies, the cytomegalovirus (CMV) promoter appeared least efficient in macaque cortex. The human synapsin-1 promoter preceded by the CMV enhancer (enhSyn1) produced homogeneous reporter gene expression across all layers, while two variants of the CaMKIIα promoter resulted in different laminar transduction patterns and cell specificities. Finally, differences in expression patterns were observed when the same viral vector was injected in two neocortical areas. Our results corroborate previous findings that reporter-gene expression patterns and efficiency of rAAV transduction depend on serotype, promoter, cortical layer, and area. PMID:26839901

In vivo gene delivery and expression by bacteriophage lambda vectors.

PubMed

Lankes, H A; Zanghi, C N; Santos, K; Capella, C; Duke, C M P; Dewhurst, S

2007-05-01

Bacteriophage vectors have potential as gene transfer and vaccine delivery vectors because of their low cost, safety and physical stability. However, little is known concerning phage-mediated gene transfer in mammalian hosts. We therefore performed experiments to examine phage-mediated gene transfer in vivo. Mice were inoculated with recombinant lambda phage containing a mammalian expression cassette encoding firefly luciferase (luc). Efficient, dose-dependent in vivo luc expression was detected, which peaked within 24 h of delivery and declined to undetectable levels within a week. Display of an integrin-binding peptide increased cellular internalization of phage in vitro and enhanced phage-mediated gene transfer in vivo. Finally, in vivo depletion of phagocytic cells using clodronate liposomes had only a minor effect on the efficiency of phage-mediated gene transfer. Unmodified lambda phage particles are capable of transducing mammalian cells in vivo, and may be taken up -- at least in part -- by nonphagocytic mechanisms. Surface modifications that enhance phage uptake result in more efficient in vivo gene transfer. These experiments shed light on the mechanisms involved in phage-mediated gene transfer in vivo, and suggest new approaches that may enhance the efficiency of this process.

Exercise training causes differential changes in gene expression in diaphragm arteries and 2A arterioles of obese rats.

PubMed

Laughlin, M Harold; Padilla, Jaume; Jenkins, Nathan T; Thorne, Pamela K; Martin, Jeffrey S; Rector, R Scott; Akter, Sadia; Davis, J Wade

2015-09-15

We employed next-generation, transcriptome-wide RNA sequencing (RNA-Seq) technology to assess the effects of two different exercise training protocols on transcriptional profiles in diaphragm second-order arterioles (D2a) and in the diaphragm feed artery (DFA) from Otsuka Long Evans Tokushima Fatty (OLETF) rats. Arterioles were isolated from the diaphragm of OLETF rats that underwent an endurance exercise training program (EX; n = 13), interval sprint training program (SPRINT; n = 14), or remained sedentary (Sed; n = 12). Our hypothesis was that exercise training would have similar effects on gene expression in the diaphragm and soleus muscle arterioles because diaphragm blood flow increases during exercise to a similar extent as in soleus. Results reveal that several canonical pathways that were significantly altered by exercise in limb skeletal muscles were not among the pathways significantly changed in the diaphragm arterioles including actin cytoskeleton signaling, role of NFAT in regulation of immune response, protein kinase A signaling, and protein ubiquitination pathway. EX training altered the expression of a smaller number of genes than did SPRINT in the DFA but induced a larger number of genes with altered expression in the D2a than did SPRINT. In fact, FDR differential expression analysis (FDR, 10%) indicated that only two genes exhibited altered expression in D2a of SPRINT rats. Very few of the genes that exhibited altered expression in the DFA or D2a were also altered in limb muscle arterioles. Finally, results indicate that the 2a arterioles of soleus muscle (S2a) from endurance-trained animals and the DFA of SPRINT animals exhibited the largest number of genes with altered expression.

Conservation of regulatory sequences and gene expression patterns in the disintegrating Drosophila Hox gene complex

PubMed Central

Negre, Bárbara; Casillas, Sònia; Suzanne, Magali; Sánchez-Herrero, Ernesto; Akam, Michael; Nefedov, Michael; Barbadilla, Antonio; de Jong, Pieter; Ruiz, Alfredo

2005-01-01

Homeotic (Hox) genes are usually clustered and arranged in the same order as they are expressed along the anteroposterior body axis of metazoans. The mechanistic explanation for this colinearity has been elusive, and it may well be that a single and universal cause does not exist. The Hox-gene complex (HOM-C) has been rearranged differently in several Drosophila species, producing a striking diversity of Hox gene organizations. We investigated the genomic and functional consequences of the two HOM-C splits present in Drosophila buzzatii. Firstly, we sequenced two regions of the D. buzzatii genome, one containing the genes labial and abdominal A, and another one including proboscipedia, and compared their organization with that of D. melanogaster and D. pseudoobscura in order to map precisely the two splits. Then, a plethora of conserved noncoding sequences, which are putative enhancers, were identified around the three Hox genes closer to the splits. The position and order of these enhancers are conserved, with minor exceptions, between the three Drosophila species. Finally, we analyzed the expression patterns of the same three genes in embryos and imaginal discs of four Drosophila species with different Hox-gene organizations. The results show that their expression patterns are conserved despite the HOM-C splits. We conclude that, in Drosophila, Hox-gene clustering is not an absolute requirement for proper function. Rather, the organization of Hox genes is modular, and their clustering seems the result of phylogenetic inertia more than functional necessity. PMID:15867430

Efficient expression systems for cysteine proteases of malaria parasites

PubMed Central

Sarduy, Emir Salas; de los A. Chávez Planes, María

2013-01-01

Papain-like cysteine proteases of malaria parasites are considered important chemotherapeutic targets or valuable models for the evaluation of drug candidates. Consequently, many of these enzymes have been cloned and expressed in Escherichia coli for their biochemical characterization. However, their expression has been problematic, showing low yield and leading to the formation of insoluble aggregates. Given that highly-productive expression systems are required for the high-throughput evaluation of inhibitors, we analyzed the existing expression systems to identify the causes of such apparent issues. We found that significant divergences in codon and nucleotide composition from host genes are the most probable cause of expression failure, and propose several strategies to overcome these limitations. Finally we predict that yeast hosts Saccharomyces cerevisiae and Pichia pastoris may be better suited than E. coli for the efficient expression of plasmodial genes, presumably leading to soluble and active products reproducing structural and functional characteristics of the natural enzymes. PMID:23018863

An Endogenous Accelerator for Viral Gene Expression Confers a Fitness Advantage

PubMed Central

Teng, Melissa W.; Bolovan-Fritts, Cynthia; Dar, Roy D.; Womack, Andrew; Simpson, Michael L.; Shenk, Thomas; Weinberger, Leor S.

2012-01-01

Many signaling circuits face a fundamental tradeoff between accelerating their response speed while maintaining final levels below a cytotoxic threshold. Here, we describe a transcriptional circuitry that dynamically converts signaling inputs into faster rates without amplifying final equilibrium levels. Using time-lapse microscopy, we find that transcriptional activators accelerate human cytomegalovirus (CMV) gene expression in single cells without amplifying steady-state expression levels, and this acceleration generates a significant replication advantage. We map the accelerator to a highly self-cooperative transcriptional negative-feedback loop (Hill coefficient ~ 7) generated by homo-multimerization of the virus’s essential transactivator protein IE2 at nuclear PML bodies. Eliminating the IE2-accelerator circuit reduces transcriptional strength through mislocalization of incoming viral genomes away from PML bodies and carries a heavy fitness cost. In general, accelerators may provide a mechanism for signal-transduction circuits to respond quickly to external signals without increasing steady-state levels of potentially cytotoxic molecules. PMID:23260143

Specificity and Heterogeneity of Terahertz Radiation Effect on Gene Expression in Mouse Mesenchymal Stem Cells

DOE PAGES

Alexandrov, Boian S.; Phipps, M. Lisa; Alexandrov, Ludmil B.; ...

2013-01-31

In this paper, we report that terahertz (THz) irradiation of mouse mesenchymal stem cells (mMSCs) with a single-frequency (SF) 2.52 THz laser or pulsed broadband (centered at 10 THz) source results in irradiation specific heterogenic changes in gene expression. The THz effect depends on irradiation parameters such as the duration and type of THz source, and on the degree of stem cell differentiation. Our microarray survey and RT-PCR experiments demonstrate that prolonged broadband THz irradiation drives mMSCs toward differentiation, while 2-hour irradiation (regardless of THz sources) affects genes transcriptionally active in pluripotent stem cells. The strictly controlled experimental environment indicatesmore » minimal temperature changes and the absence of any discernable response to heat shock and cellular stress genes imply a non-thermal response. Computer simulations of the core promoters of two pluripotency markers reveal association between gene upregulation and propensity for DNA breathing. Finally, we propose that THz radiation has potential for non-contact control of cellular gene expression.« less

The Renilla luciferase gene as a reference gene for normalization of gene expression in transiently transfected cells.

PubMed

Jiwaji, Meesbah; Daly, Rónán; Pansare, Kshama; McLean, Pauline; Yang, Jingli; Kolch, Walter; Pitt, Andrew R

2010-12-31

The importance of appropriate normalization controls in quantitative real-time polymerase chain reaction (qPCR) experiments has become more apparent as the number of biological studies using this methodology has increased. In developing a system to study gene expression from transiently transfected plasmids, it became clear that normalization using chromosomally encoded genes is not ideal, at it does not take into account the transfection efficiency and the significantly lower expression levels of the plasmids. We have developed and validated a normalization method for qPCR using a co-transfected plasmid. The best chromosomal gene for normalization in the presence of the transcriptional activators used in this study, cadmium, dexamethasone, forskolin and phorbol-12-myristate 13-acetate was first identified. qPCR data was analyzed using geNorm, Normfinder and BestKeeper. Each software application was found to rank the normalization controls differently with no clear correlation. Including a co-transfected plasmid encoding the Renilla luciferase gene (Rluc) in this analysis showed that its calculated stability was not as good as the optimised chromosomal genes, most likely as a result of the lower expression levels and transfection variability. Finally, we validated these analyses by testing two chromosomal genes (B2M and ActB) and a co-transfected gene (Rluc) under biological conditions. When analyzing co-transfected plasmids, Rluc normalization gave the smallest errors compared to the chromosomal reference genes. Our data demonstrates that transfected Rluc is the most appropriate normalization reference gene for transient transfection qPCR analysis; it significantly reduces the standard deviation within biological experiments as it takes into account the transfection efficiencies and has easily controllable expression levels. This improves reproducibility, data validity and most importantly, enables accurate interpretation of qPCR data.

Evaluation and Selection of Candidate Reference Genes for Normalization of Quantitative RT-PCR in Withania somnifera (L.) Dunal

PubMed Central

Singh, Varinder; Kaul, Sunil C.; Wadhwa, Renu; Pati, Pratap Kumar

2015-01-01

Quantitative real-time PCR (qRT-PCR) is now globally used for accurate analysis of transcripts levels in plants. For reliable quantification of transcripts, identification of the best reference genes is a prerequisite in qRT-PCR analysis. Recently, Withania somnifera has attracted lot of attention due to its immense therapeutic potential. At present, biotechnological intervention for the improvement of this plant is being seriously pursued. In this background, it is important to have comprehensive studies on finding suitable reference genes for this high valued medicinal plant. In the present study, 11 candidate genes were evaluated for their expression stability under biotic (fungal disease), abiotic (wounding, salt, drought, heat and cold) stresses, in different plant tissues and in response to various plant growth regulators (methyl jasmonate, salicylic acid, abscisic acid). The data as analyzed by various software packages (geNorm, NormFinder, Bestkeeper and ΔCt method) suggested that cyclophilin (CYP) is a most stable gene under wounding, heat, methyl jasmonate, different tissues and all stress conditions. T-SAND was found to be a best reference gene for salt and salicylic acid (SA) treated samples, while 26S ribosomal RNA (26S), ubiquitin (UBQ) and beta-tubulin (TUB) were the most stably expressed genes under drought, biotic and cold treatment respectively. For abscisic acid (ABA) treated samples 18S-rRNA was found to stably expressed gene. Finally, the relative expression level of the three genes involved in the withanolide biosynthetic pathway was detected to validate the selection of reliable reference genes. The present work will significantly contribute to gene analysis studies in W. somnifera and facilitate in improving the quality of gene expression data in this plant as well as and other related plant species. PMID:25769035

Genome-wide identification and analysis of the SBP-box family genes in apple (Malus × domestica Borkh.).

PubMed

Li, Jun; Hou, Hongmin; Li, Xiaoqin; Xiang, Jiang; Yin, Xiangjing; Gao, Hua; Zheng, Yi; Bassett, Carole L; Wang, Xiping

2013-09-01

SQUAMOSA promoter binding protein (SBP)-box genes encode a family of plant-specific transcription factors and play many crucial roles in plant development. In this study, 27 SBP-box gene family members were identified in the apple (Malus × domestica Borkh.) genome, 15 of which were suggested to be putative targets of MdmiR156. Plant SBPs were classified into eight groups according to the phylogenetic analysis of SBP-domain proteins. Gene structure, gene chromosomal location and synteny analyses of MdSBP genes within the apple genome demonstrated that tandem and segmental duplications, as well as whole genome duplications, have likely contributed to the expansion and evolution of the SBP-box gene family in apple. Additionally, synteny analysis between apple and Arabidopsis indicated that several paired homologs of MdSBP and AtSPL genes were located in syntenic genomic regions. Tissue-specific expression analysis of MdSBP genes in apple demonstrated their diversified spatiotemporal expression patterns. Most MdmiR156-targeted MdSBP genes, which had relatively high transcript levels in stems, leaves, apical buds and some floral organs, exhibited a more differential expression pattern than most MdmiR156-nontargeted MdSBP genes. Finally, expression analysis of MdSBP genes in leaves upon various plant hormone treatments showed that many MdSBP genes were responsive to different plant hormones, indicating that MdSBP genes may be involved in responses to hormone signaling during stress or in apple development. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Differences in Flower Transcriptome between Grapevine Clones Are Related to Their Cluster Compactness, Fruitfulness, and Berry Size

PubMed Central

Grimplet, Jérôme; Tello, Javier; Laguna, Natalia; Ibáñez, Javier

2017-01-01

Grapevine cluster compactness has a clear impact on fruit quality and health status, as clusters with greater compactness are more susceptible to pests and diseases and ripen more asynchronously. Different parameters related to inflorescence and cluster architecture (length, width, branching, etc.), fruitfulness (number of berries, number of seeds) and berry size (length, width) contribute to the final level of compactness. From a collection of 501 clones of cultivar Garnacha Tinta, two compact and two loose clones with stable differences for cluster compactness-related traits were selected and phenotyped. Key organs and developmental stages were selected for sampling and transcriptomic analyses. Comparison of global gene expression patterns in flowers at the end of bloom allowed identification of potential gene networks with a role in determining the final berry number, berry size and ultimately cluster compactness. A large portion of the differentially expressed genes were found in networks related to cell division (carbohydrates uptake, cell wall metabolism, cell cycle, nucleic acids metabolism, cell division, DNA repair). Their greater expression level in flowers of compact clones indicated that the number of berries and the berry size at ripening appear related to the rate of cell replication in flowers during the early growth stages after pollination. In addition, fluctuations in auxin and gibberellin signaling and transport related gene expression support that they play a central role in fruit set and impact berry number and size. Other hormones, such as ethylene and jasmonate may differentially regulate indirect effects, such as defense mechanisms activation or polyphenols production. This is the first transcriptomic based analysis focused on the discovery of the underlying gene networks involved in grapevine traits of grapevine cluster compactness, berry number and berry size. PMID:28496449

Differences in Flower Transcriptome between Grapevine Clones Are Related to Their Cluster Compactness, Fruitfulness, and Berry Size.

PubMed

Grimplet, Jérôme; Tello, Javier; Laguna, Natalia; Ibáñez, Javier

2017-01-01

Grapevine cluster compactness has a clear impact on fruit quality and health status, as clusters with greater compactness are more susceptible to pests and diseases and ripen more asynchronously. Different parameters related to inflorescence and cluster architecture (length, width, branching, etc.), fruitfulness (number of berries, number of seeds) and berry size (length, width) contribute to the final level of compactness. From a collection of 501 clones of cultivar Garnacha Tinta, two compact and two loose clones with stable differences for cluster compactness-related traits were selected and phenotyped. Key organs and developmental stages were selected for sampling and transcriptomic analyses. Comparison of global gene expression patterns in flowers at the end of bloom allowed identification of potential gene networks with a role in determining the final berry number, berry size and ultimately cluster compactness. A large portion of the differentially expressed genes were found in networks related to cell division (carbohydrates uptake, cell wall metabolism, cell cycle, nucleic acids metabolism, cell division, DNA repair). Their greater expression level in flowers of compact clones indicated that the number of berries and the berry size at ripening appear related to the rate of cell replication in flowers during the early growth stages after pollination. In addition, fluctuations in auxin and gibberellin signaling and transport related gene expression support that they play a central role in fruit set and impact berry number and size. Other hormones, such as ethylene and jasmonate may differentially regulate indirect effects, such as defense mechanisms activation or polyphenols production. This is the first transcriptomic based analysis focused on the discovery of the underlying gene networks involved in grapevine traits of grapevine cluster compactness, berry number and berry size.

Developmental regulation of gonadotropin-releasing hormone gene expression by the MSX and DLX homeodomain protein families.

PubMed

Givens, Marjory L; Rave-Harel, Naama; Goonewardena, Vinodha D; Kurotani, Reiko; Berdy, Sara E; Swan, Christo H; Rubenstein, John L R; Robert, Benoit; Mellon, Pamela L

2005-05-13

Gonadotropin-releasing hormone (GnRH) is the central regulator of the hypothalamic-pituitary-gonadal axis, controlling sexual maturation and fertility in diverse species from fish to humans. GnRH gene expression is limited to a discrete population of neurons that migrate through the nasal region into the hypothalamus during embryonic development. The GnRH regulatory region contains four conserved homeodomain binding sites (ATTA) that are essential for basal promoter activity and cell-specific expression of the GnRH gene. MSX and DLX are members of the Antennapedia class of non-Hox homeodomain transcription factors that regulate gene expression and influence development of the craniofacial structures and anterior forebrain. Here, we report that expression patterns of the Msx and Dlx families of homeodomain transcription factors largely coincide with the migratory route of GnRH neurons and co-express with GnRH in neurons during embryonic development. In addition, MSX and DLX family members bind directly to the ATTA consensus sequences and regulate transcriptional activity of the GnRH promoter. Finally, mice lacking MSX1 or DLX1 and 2 show altered numbers of GnRH-expressing cells in regions where these factors likely function. These findings strongly support a role for MSX and DLX in contributing to spatiotemporal regulation of GnRH transcription during development.

Development of novel types of plastid transformation vectors and evaluation of factors controlling expression.

PubMed

Herz, Stefan; Füssl, Monika; Steiger, Sandra; Koop, Hans-Ulrich

2005-12-01

Two new vector types for plastid transformation were developed and uidA reporter gene expression was compared to standard transformation vectors. The first vector type does not contain any plastid promoter, instead it relies on extension of existing plastid operons and was therefore named "operon-extension" vector. When a strongly expressed plastid operon like psbA was extended by the reporter gene with this vector type, the expression level was superior to that of a standard vector under control of the 16S rRNA promoter. Different insertion sites, promoters and 5'-UTRs were analysed for their effect on reporter gene expression with standard and operon-extension vectors. The 5'-UTR of phage 7 gene 10 in combination with a modified N-terminus was found to yield the highest expression levels. Expression levels were also strongly dependent on external factors like plant or leaf age or light intensity. In the second vector type, named "split" plastid transformation vector, modules of the expression cassette were distributed on two separate vectors. Upon co-transformation of plastids with these vectors, the complete expression cassette became inserted into the plastome. This result can be explained by successive co-integration of the split vectors and final loop-out recombination of the duplicated sequences. The split vector concept was validated with different vector pairs.

eXpression2Kinases (X2K) Web: linking expression signatures to upstream cell signaling networks.

PubMed

Clarke, Daniel J B; Kuleshov, Maxim V; Schilder, Brian M; Torre, Denis; Duffy, Mary E; Keenan, Alexandra B; Lachmann, Alexander; Feldmann, Axel S; Gundersen, Gregory W; Silverstein, Moshe C; Wang, Zichen; Ma'ayan, Avi

2018-05-25

While gene expression data at the mRNA level can be globally and accurately measured, profiling the activity of cell signaling pathways is currently much more difficult. eXpression2Kinases (X2K) computationally predicts involvement of upstream cell signaling pathways, given a signature of differentially expressed genes. X2K first computes enrichment for transcription factors likely to regulate the expression of the differentially expressed genes. The next step of X2K connects these enriched transcription factors through known protein-protein interactions (PPIs) to construct a subnetwork. The final step performs kinase enrichment analysis on the members of the subnetwork. X2K Web is a new implementation of the original eXpression2Kinases algorithm with important enhancements. X2K Web includes many new transcription factor and kinase libraries, and PPI networks. For demonstration, thousands of gene expression signatures induced by kinase inhibitors, applied to six breast cancer cell lines, are provided for fetching directly into X2K Web. The results are displayed as interactive downloadable vector graphic network images and bar graphs. Benchmarking various settings via random permutations enabled the identification of an optimal set of parameters to be used as the default settings in X2K Web. X2K Web is freely available from http://X2K.cloud.

Prediction of epigenetically regulated genes in breast cancer cell lines.

PubMed

Loss, Leandro A; Sadanandam, Anguraj; Durinck, Steffen; Nautiyal, Shivani; Flaucher, Diane; Carlton, Victoria E H; Moorhead, Martin; Lu, Yontao; Gray, Joe W; Faham, Malek; Spellman, Paul; Parvin, Bahram

2010-06-04

Methylation of CpG islands within the DNA promoter regions is one mechanism that leads to aberrant gene expression in cancer. In particular, the abnormal methylation of CpG islands may silence associated genes. Therefore, using high-throughput microarrays to measure CpG island methylation will lead to better understanding of tumor pathobiology and progression, while revealing potentially new biomarkers. We have examined a recently developed high-throughput technology for measuring genome-wide methylation patterns called mTACL. Here, we propose a computational pipeline for integrating gene expression and CpG island methylation profiles to identify epigenetically regulated genes for a panel of 45 breast cancer cell lines, which is widely used in the Integrative Cancer Biology Program (ICBP). The pipeline (i) reduces the dimensionality of the methylation data, (ii) associates the reduced methylation data with gene expression data, and (iii) ranks methylation-expression associations according to their epigenetic regulation. Dimensionality reduction is performed in two steps: (i) methylation sites are grouped across the genome to identify regions of interest, and (ii) methylation profiles are clustered within each region. Associations between the clustered methylation and the gene expression data sets generate candidate matches within a fixed neighborhood around each gene. Finally, the methylation-expression associations are ranked through a logistic regression, and their significance is quantified through permutation analysis. Our two-step dimensionality reduction compressed 90% of the original data, reducing 137,688 methylation sites to 14,505 clusters. Methylation-expression associations produced 18,312 correspondences, which were used to further analyze epigenetic regulation. Logistic regression was used to identify 58 genes from these correspondences that showed a statistically significant negative correlation between methylation profiles and gene expression in the panel of breast cancer cell lines. Subnetwork enrichment of these genes has identified 35 common regulators with 6 or more predicted markers. In addition to identifying epigenetically regulated genes, we show evidence of differentially expressed methylation patterns between the basal and luminal subtypes. Our results indicate that the proposed computational protocol is a viable platform for identifying epigenetically regulated genes. Our protocol has generated a list of predictors including COL1A2, TOP2A, TFF1, and VAV3, genes whose key roles in epigenetic regulation is documented in the literature. Subnetwork enrichment of these predicted markers further suggests that epigenetic regulation of individual genes occurs in a coordinated fashion and through common regulators.

IP-10, p53, and Foxp3 Expression in Hepatocytes of Chronic Hepatitis B Patients with Cirrhosis and Hepatocellular Carcinoma

PubMed Central

Munshi, Saifullah; Jahan, Munira; Nessa, Afzalun; Alam, Shahinul; Tabassum, Shahina

2016-01-01

ABSTRACT Aim Elucidating differences in gene expression may be useful in understanding the molecular pathogenesis and for developing specific markers for the outcome of hepatitis B virus (HBV) infection. In the present study, expressions of host gene interferon gamma-inducible protein (IP-10), p53, and Foxp3 were studied in hepatocytes of patients with chronic HBV infection to determine a possible link between selected host gene expression and the outcome of HBV infection. Materials and methods The study was conducted in 60 patients with chronic HBV infection and they were divided into four groups: HBV-positive cirrhosis (n = 15), HBV-negative cirrhosis (n = 15), HBV-positive hepatocellular carcinoma (HCC) (n = 15) and HBV-negative HCC (n = 15). Total messenger ribonucleic acid (mRNA) extraction was done followed by complementary deoxyribonucleic acid (cDNA) synthesis, and finally gene expression was performed using real-time polymerase chain reaction (PCR) technique. Results IP-10 and p53 gene expressions were lower in HBV-positive cirrhosis, and Foxp3 gene expression was upregulated in HBV-positive cirrhosis in comparison to HBV-negative cirrhosis. The expressions of all the three genes were upregulated among HBV-positive HCC in comparison to HBV-negative HCC. The expression of IP-10, p53, and Foxp3 genes was upregulated in HBV-positive HCC in comparison to HBV-positive cirrhosis. Conclusion This study indicates that there are variations in the expression of the selected genes among cirrhosis and HCC patients with or without HBV. All the three selected genes were more or less upregulated in HBV-positive HCC patients, but only Foxp3 expression was upregulated in HBV-positive cirrhosis. These three particular genes may have a role in the molecular pathogenesis and clinical outcome of HBV-positive cirrhosis and HCC patients. These aspects need further evaluation by studies with larger numbers of cirrhosis and HCC patients. How to cite this article Shahera U, Munshi S, Jahan M, Nessa A, Alam S, Tabassum S. IP-10, p53, and Foxp3 Expression in Hepatocytes of Chronic Hepatitis B Patients with Cirrhosis and Hepatocellular Carcinoma. Euroasian J Hepato-Gastroenterol 2016;6(2):149-153. PMID:29201748

Gene Expression Profiling Reveals a Massive, Aneuploidy-Dependent Transcriptional Deregulation and Distinct Differences between Lymph Node–Negative and Lymph Node–Positive Colon Carcinomas

PubMed Central

Grade, Marian; Hörmann, Patrick; Becker, Sandra; Hummon, Amanda B.; Wangsa, Danny; Varma, Sudhir; Simon, Richard; Liersch, Torsten; Becker, Heinz; Difilippantonio, Michael J.; Ghadimi, B. Michael; Ried, Thomas

2016-01-01

To characterize patterns of global transcriptional deregulation in primary colon carcinomas, we did gene expression profiling of 73 tumors [Unio Internationale Contra Cancrum stage II (n = 33) and stage III (n = 40)] using oligonucleotide microarrays. For 30 of the tumors, expression profiles were compared with those from matched normal mucosa samples. We identified a set of 1,950 genes with highly significant deregulation between tumors and mucosa samples (P < 1e–7). A significant proportion of these genes mapped to chromosome 20 (P = 0.01). Seventeen genes had a >5-fold average expression difference between normal colon mucosa and carcinomas, including up-regulation of MYC and of HMGA1, a putative oncogene. Furthermore, we identified 68 genes that were significantly differentially expressed between lymph node–negative and lymph node–positive tumors (P < 0.001), the functional annotation of which revealed a preponderance of genes that play a role in cellular immune response and surveillance. The microarray-derived gene expression levels of 20 deregulated genes were validated using quantitative real-time reverse transcription-PCR in >40 tumor and normal mucosa samples with good concordance between the techniques. Finally, we established a relationship between specific genomic imbalances, which were mapped for 32 of the analyzed colon tumors by comparative genomic hybridization, and alterations of global transcriptional activity. Previously, we had conducted a similar analysis of primary rectal carcinomas. The systematic comparison of colon and rectal carcinomas revealed a significant overlap of genomic imbalances and transcriptional deregulation, including activation of the Wnt/β-catenin signaling cascade, suggesting similar pathogenic pathways. PMID:17210682

Gene expression profiling reveals a massive, aneuploidy-dependent transcriptional deregulation and distinct differences between lymph node-negative and lymph node-positive colon carcinomas.

PubMed

Grade, Marian; Hörmann, Patrick; Becker, Sandra; Hummon, Amanda B; Wangsa, Danny; Varma, Sudhir; Simon, Richard; Liersch, Torsten; Becker, Heinz; Difilippantonio, Michael J; Ghadimi, B Michael; Ried, Thomas

2007-01-01

To characterize patterns of global transcriptional deregulation in primary colon carcinomas, we did gene expression profiling of 73 tumors [Unio Internationale Contra Cancrum stage II (n = 33) and stage III (n = 40)] using oligonucleotide microarrays. For 30 of the tumors, expression profiles were compared with those from matched normal mucosa samples. We identified a set of 1,950 genes with highly significant deregulation between tumors and mucosa samples (P < 1e-7). A significant proportion of these genes mapped to chromosome 20 (P = 0.01). Seventeen genes had a >5-fold average expression difference between normal colon mucosa and carcinomas, including up-regulation of MYC and of HMGA1, a putative oncogene. Furthermore, we identified 68 genes that were significantly differentially expressed between lymph node-negative and lymph node-positive tumors (P < 0.001), the functional annotation of which revealed a preponderance of genes that play a role in cellular immune response and surveillance. The microarray-derived gene expression levels of 20 deregulated genes were validated using quantitative real-time reverse transcription-PCR in >40 tumor and normal mucosa samples with good concordance between the techniques. Finally, we established a relationship between specific genomic imbalances, which were mapped for 32 of the analyzed colon tumors by comparative genomic hybridization, and alterations of global transcriptional activity. Previously, we had conducted a similar analysis of primary rectal carcinomas. The systematic comparison of colon and rectal carcinomas revealed a significant overlap of genomic imbalances and transcriptional deregulation, including activation of the Wnt/beta-catenin signaling cascade, suggesting similar pathogenic pathways.

Exploring valid internal-control genes in Porphyra yezoensis (Bangiaceae) during stress response conditions

NASA Astrophysics Data System (ADS)

Wang, Wenlei; Wu, Xiaojie; Wang, Chao; Jia, Zhaojun; He, Linwen; Wei, Yifan; Niu, Jianfeng; Wang, Guangce

2014-07-01

To screen the stable expression genes related to the stress (strong light, dehydration and temperature shock) we applied Absolute real-time PCR technology to determine the transcription numbers of the selected test genes in P orphyra yezoensis, which has been regarded as a potential model species responding the stress conditions in the intertidal. Absolute real-time PCR technology was applied to determine the transcription numbers of the selected test genes in P orphyra yezoensis, which has been regarded as a potential model species in stress responding. According to the results of photosynthesis parameters, we observed that Y(II) and F v/ F m were significantly affected when stress was imposed on the thalli of P orphyra yezoensis, but underwent almost completely recovered under normal conditions, which were collected for the following experiments. Then three samples, which were treated with different grade stresses combined with salinity, irradiation and temperature, were collected. The transcription numbers of seven constitutive expression genes in above samples were determined after RNA extraction and cDNA synthesis. Finally, a general insight into the selection of internal control genes during stress response was obtained. We found that there were no obvious effects in terms of salinity stress (at salinity 90) on transcription of most genes used in the study. The 18S ribosomal RNA gene had the highest expression level, varying remarkably among different tested groups. RPS8 expression showed a high irregular variance between samples. GAPDH presented comparatively stable expression and could thus be selected as the internal control. EF-1α showed stable expression during the series of multiple-stress tests. Our research provided available references for the selection of internal control genes for transcripts determination of P. yezoensis.

Segmentation gene expression patterns in Bactrocera dorsalis and related insects: regulation and shape of blastoderm and larval cuticle.

PubMed

Suksuwan, Worramin; Cai, Xiaoli; Ngernsiri, Lertluk; Baumgartner, Stefan

2017-01-01

The oriental fruit fly, Bactrocera dorsalis, is regarded as a severe pest of fruit production in Asia. Despite its economic importance, only limited information regarding the molecular and developmental biology of this insect is known to date. We provide a detailed analysis of B. dorsalis embryology, as well as the expression patterns of a number of segmentation genes known to act during patterning of Drosophila and compare these to the patterns of other insect families. An anterior shift of the expression of gap genes was detected when compared to Drosophila. This shift was largely restored during the step where the gap genes control expression of the pair-rule genes. We analyzed and compared the shapes of the embryos of insects of different families, B. dorsalis and the blow fly Lucilia sericata with that of the well-characterized Drosophila melanogaster. We found distinct shapes as well as differences in the ratios of the length of the anterior-posterior axis and the dorsal-ventral axis. These features were integrated into a profile of how the expression patterns of the gap gene Krüppel and the pair-rule gene even-skipped were observed along the A-P axis in three insects families. Since significant differences were observed, we discuss how Krüppel controls the even-skipped stripes. Furthermore, we discuss how the position and angles of the segmentation gene stripes differed from other insects. Finally, we analyzed the outcome of the expression patterns of the late acting segment polarity genes in relation to the anlagen of the naked-cuticle and denticle belt area of the B. dorsalis larva.

A convex optimization approach for identification of human tissue-specific interactomes.

PubMed

Mohammadi, Shahin; Grama, Ananth

2016-06-15

Analysis of organism-specific interactomes has yielded novel insights into cellular function and coordination, understanding of pathology, and identification of markers and drug targets. Genes, however, can exhibit varying levels of cell type specificity in their expression, and their coordinated expression manifests in tissue-specific function and pathology. Tissue-specific/tissue-selective interaction mechanisms have significant applications in drug discovery, as they are more likely to reveal drug targets. Furthermore, tissue-specific transcription factors (tsTFs) are significantly implicated in human disease, including cancers. Finally, disease genes and protein complexes have the tendency to be differentially expressed in tissues in which defects cause pathology. These observations motivate the construction of refined tissue-specific interactomes from organism-specific interactomes. We present a novel technique for constructing human tissue-specific interactomes. Using a variety of validation tests (Edge Set Enrichment Analysis, Gene Ontology Enrichment, Disease-Gene Subnetwork Compactness), we show that our proposed approach significantly outperforms state-of-the-art techniques. Finally, using case studies of Alzheimer's and Parkinson's diseases, we show that tissue-specific interactomes derived from our study can be used to construct pathways implicated in pathology and demonstrate the use of these pathways in identifying novel targets. http://www.cs.purdue.edu/homes/mohammas/projects/ActPro.html mohammadi@purdue.edu. © The Author 2016. Published by Oxford University Press.

Identification of Cell Cycle-regulated Genes in Fission YeastD⃞

PubMed Central

Peng, Xu; Karuturi, R. Krishna Murthy; Miller, Lance D.; Lin, Kui; Jia, Yonghui; Kondu, Pinar; Wang, Long; Wong, Lim-Soon; Liu, Edison T.; Balasubramanian, Mohan K.; Liu, Jianhua

2005-01-01

Cell cycle progression is both regulated and accompanied by periodic changes in the expression levels of a large number of genes. To investigate cell cycle-regulated transcriptional programs in the fission yeast Schizosaccharomyces pombe, we developed a whole-genome oligonucleotide-based DNA microarray. Microarray analysis of both wild-type and cdc25 mutant cell cultures was performed to identify transcripts whose levels oscillated during the cell cycle. Using an unsupervised algorithm, we identified 747 genes that met the criteria for cell cycle-regulated expression. Peaks of gene expression were found to be distributed throughout the entire cell cycle. Furthermore, we found that four promoter motifs exhibited strong association with cell cycle phase-specific expression. Examination of the regulation of MCB motif-containing genes through the perturbation of DNA synthesis control/MCB-binding factor (DSC/MBF)-mediated transcription in arrested synchronous cdc10 mutant cell cultures revealed a subset of functional targets of the DSC/MBF transcription factor complex, as well as certain gene promoter requirements. Finally, we compared our data with those for the budding yeast Saccharomyces cerevisiae and found ∼140 genes that are cell cycle regulated in both yeasts, suggesting that these genes may play an evolutionarily conserved role in regulation of cell cycle-specific processes. Our complete data sets are available at http://giscompute.gis.a-star.edu.sg/~gisljh/CDC. PMID:15616197

Complete TCRα gene locus control region activity in T cells derived in vitro from embryonic stem cells

PubMed Central

Lahiji, Armin; Kučerová-Levisohn, Martina; Lovett, Jordana; Holmes, Roxanne; Zúñiga-Pflücker, Juan Carlos; Ortiz, Benjamin D.

2013-01-01

Locus Control Regions (LCR) are cis-acting gene regulatory elements with the unique, integration site-independent ability to transfer the characteristics of their locus-of-origin’s gene expression pattern to a linked transgene in mice. LCR activities have been discovered in numerous T cell lineage expressed gene loci. These elements can be adapted to the design of stem cell gene therapy vectors that direct robust therapeutic gene expression to the T cell progeny of engineered stem cells. Currently, transgenic mice provide the only experimental approach that wholly supports all the critical aspects of LCR activity. Herein we report manifestation of all key features of mouse T cell receptor (TCR)-α gene LCR function in T cells derived in vitro from mouse embryonic stem cells (ESC). High level, copy number-related TCRα LCR-linked reporter gene expression levels are cell type-restricted in this system, and upregulated during the expected stage transition of T cell development. We further report that de novo introduction of TCRα LCR linked transgenes into existing T cell lines yields incomplete LCR activity. Together, these data indicate that establishing full TCRα LCR activity requires critical molecular events occurring prior to final T-lineage determination. This study additionally validates a novel, tractable and more rapid approach for the study of LCR activity in T cells, and its translation to therapeutic genetic engineering. PMID:23720809

Analysis of blood-based gene expression in idiopathic Parkinson disease.

PubMed

Shamir, Ron; Klein, Christine; Amar, David; Vollstedt, Eva-Juliane; Bonin, Michael; Usenovic, Marija; Wong, Yvette C; Maver, Ales; Poths, Sven; Safer, Hershel; Corvol, Jean-Christophe; Lesage, Suzanne; Lavi, Ofer; Deuschl, Günther; Kuhlenbaeumer, Gregor; Pawlack, Heike; Ulitsky, Igor; Kasten, Meike; Riess, Olaf; Brice, Alexis; Peterlin, Borut; Krainc, Dimitri

2017-10-17

To examine whether gene expression analysis of a large-scale Parkinson disease (PD) patient cohort produces a robust blood-based PD gene signature compared to previous studies that have used relatively small cohorts (≤220 samples). Whole-blood gene expression profiles were collected from a total of 523 individuals. After preprocessing, the data contained 486 gene profiles (n = 205 PD, n = 233 controls, n = 48 other neurodegenerative diseases) that were partitioned into training, validation, and independent test cohorts to identify and validate a gene signature. Batch-effect reduction and cross-validation were performed to ensure signature reliability. Finally, functional and pathway enrichment analyses were applied to the signature to identify PD-associated gene networks. A gene signature of 100 probes that mapped to 87 genes, corresponding to 64 upregulated and 23 downregulated genes differentiating between patients with idiopathic PD and controls, was identified with the training cohort and successfully replicated in both an independent validation cohort (area under the curve [AUC] = 0.79, p = 7.13E-6) and a subsequent independent test cohort (AUC = 0.74, p = 4.2E-4). Network analysis of the signature revealed gene enrichment in pathways, including metabolism, oxidation, and ubiquitination/proteasomal activity, and misregulation of mitochondria-localized genes, including downregulation of COX4I1 , ATP5A1 , and VDAC3 . We present a large-scale study of PD gene expression profiling. This work identifies a reliable blood-based PD signature and highlights the importance of large-scale patient cohorts in developing potential PD biomarkers. © 2017 American Academy of Neurology.

Semantic integration of gene expression analysis tools and data sources using software connectors

PubMed Central

2013-01-01

Background The study and analysis of gene expression measurements is the primary focus of functional genomics. Once expression data is available, biologists are faced with the task of extracting (new) knowledge associated to the underlying biological phenomenon. Most often, in order to perform this task, biologists execute a number of analysis activities on the available gene expression dataset rather than a single analysis activity. The integration of heteregeneous tools and data sources to create an integrated analysis environment represents a challenging and error-prone task. Semantic integration enables the assignment of unambiguous meanings to data shared among different applications in an integrated environment, allowing the exchange of data in a semantically consistent and meaningful way. This work aims at developing an ontology-based methodology for the semantic integration of gene expression analysis tools and data sources. The proposed methodology relies on software connectors to support not only the access to heterogeneous data sources but also the definition of transformation rules on exchanged data. Results We have studied the different challenges involved in the integration of computer systems and the role software connectors play in this task. We have also studied a number of gene expression technologies, analysis tools and related ontologies in order to devise basic integration scenarios and propose a reference ontology for the gene expression domain. Then, we have defined a number of activities and associated guidelines to prescribe how the development of connectors should be carried out. Finally, we have applied the proposed methodology in the construction of three different integration scenarios involving the use of different tools for the analysis of different types of gene expression data. Conclusions The proposed methodology facilitates the development of connectors capable of semantically integrating different gene expression analysis tools and data sources. The methodology can be used in the development of connectors supporting both simple and nontrivial processing requirements, thus assuring accurate data exchange and information interpretation from exchanged data. PMID:24341380

Involvement of Retinoblastoma Protein and HBP1 in Histone H10 Gene Expression

PubMed Central

Lemercier, Claudie; Duncliffe, Kym; Boibessot, Isabelle; Zhang, Hui; Verdel, André; Angelov, Dimitar; Khochbin, Saadi

2000-01-01

The histone H10-encoding gene is expressed in vertebrates in differentiating cells during the arrest of proliferation. In the H10 promoter, a specific regulatory element, which we named the H4 box, exhibits features which implicate a role in mediating H10 gene expression in response to both differentiation and cell cycle control signals. For instance, within the linker histone gene family, the H4 box is found only in the promoters of differentiation-associated subtypes, suggesting that it is specifically involved in differentiation-dependent expression of these genes. In addition, an element nearly identical to the H4 box is conserved in the promoters of histone H4-encoding genes and is known to be involved in their cell cycle-dependent expression. The transcription factors interacting with the H10 H4 box were therefore expected to link differentiation-dependent expression of H10 to the cell cycle control machinery. The aim of this work was to identify such transcription factors and to obtain information concerning the regulatory pathway involved. Interestingly, our cloning strategy led to the isolation of a retinoblastoma protein (RB) partner known as HBP1. HBP1, a high-mobility group box transcription factor, interacted specifically with the H10 H4 box and moreover was expressed in a differentiation-dependent manner. We also showed that the HBP1-encoding gene is able to produce different forms of HBP1. Finally, we demonstrated that both HBP1 and RB were involved in the activation of H10 gene expression. We therefore propose that HBP1 mediates a link between the cell cycle control machinery and cell differentiation signals. Through modulating the expression of specific chromatin-associated proteins such as histone H10, HBP1 plays a vital role in chromatin remodeling events during the arrest of cell proliferation in differentiating cells. PMID:10958660

Semantic integration of gene expression analysis tools and data sources using software connectors.

PubMed

Miyazaki, Flávia A; Guardia, Gabriela D A; Vêncio, Ricardo Z N; de Farias, Cléver R G

2013-10-25

The study and analysis of gene expression measurements is the primary focus of functional genomics. Once expression data is available, biologists are faced with the task of extracting (new) knowledge associated to the underlying biological phenomenon. Most often, in order to perform this task, biologists execute a number of analysis activities on the available gene expression dataset rather than a single analysis activity. The integration of heterogeneous tools and data sources to create an integrated analysis environment represents a challenging and error-prone task. Semantic integration enables the assignment of unambiguous meanings to data shared among different applications in an integrated environment, allowing the exchange of data in a semantically consistent and meaningful way. This work aims at developing an ontology-based methodology for the semantic integration of gene expression analysis tools and data sources. The proposed methodology relies on software connectors to support not only the access to heterogeneous data sources but also the definition of transformation rules on exchanged data. We have studied the different challenges involved in the integration of computer systems and the role software connectors play in this task. We have also studied a number of gene expression technologies, analysis tools and related ontologies in order to devise basic integration scenarios and propose a reference ontology for the gene expression domain. Then, we have defined a number of activities and associated guidelines to prescribe how the development of connectors should be carried out. Finally, we have applied the proposed methodology in the construction of three different integration scenarios involving the use of different tools for the analysis of different types of gene expression data. The proposed methodology facilitates the development of connectors capable of semantically integrating different gene expression analysis tools and data sources. The methodology can be used in the development of connectors supporting both simple and nontrivial processing requirements, thus assuring accurate data exchange and information interpretation from exchanged data.

Human Cytomegalovirus pUL97 Regulates the Viral Major Immediate Early Promoter by Phosphorylation-Mediated Disruption of Histone Deacetylase 1 Binding

PubMed Central

Bigley, Tarin M.; Reitsma, Justin M.; Mirza, Shama P.

2013-01-01

Human cytomegalovirus (HCMV) is a common agent of congenital infection and causes severe disease in immunocompromised patients. Current approved therapies focus on inhibiting viral DNA replication. The HCMV kinase pUL97 contributes to multiple stages of viral infection including DNA replication, controlling the cell cycle, and virion maturation. Our studies demonstrate that pUL97 also functions by influencing immediate early (IE) gene expression during the initial stages of infection. Inhibition of kinase activity using the antiviral compound maribavir or deletion of the UL97 gene resulted in decreased expression of viral immediate early genes during infection. Expression of pUL97 was sufficient to transactivate IE1 gene expression from the viral genome, which was dependent on viral kinase activity. We observed that pUL97 associates with histone deacetylase 1 (HDAC1). HDAC1 is a transcriptional corepressor that acts to silence expression of viral genes. We observed that inhibition or deletion of pUL97 kinase resulted in increased HDAC1 and decreased histone H3 lysine 9 acetylation associating with the viral major immediate early (MIE) promoter. IE expression during pUL97 inhibition or deletion was rescued following inhibition of deacetylase activity. HDAC1 associates with chromatin by protein-protein interactions. Expression of active but not inactive pUL97 kinase decreased HDAC1 interaction with the transcriptional repressor protein DAXX. Finally, using mass spectrometry, we found that HDAC1 is uniquely phosphorylated upon expression of pUL97. Our results support the conclusion that HCMV pUL97 kinase regulates viral immediate early gene expression by phosphorylation-mediated disruption of HDAC1 binding to the MIE promoter. PMID:23616659

Hormone-dependent control of developmental timing through regulation of chromatin accessibility

PubMed Central

Uyehara, Christopher M.; Nystrom, Spencer L.; Niederhuber, Matthew J.; Leatham-Jensen, Mary; Ma, Yiqin; Buttitta, Laura A.

2017-01-01

Specification of tissue identity during development requires precise coordination of gene expression in both space and time. Spatially, master regulatory transcription factors are required to control tissue-specific gene expression programs. However, the mechanisms controlling how tissue-specific gene expression changes over time are less well understood. Here, we show that hormone-induced transcription factors control temporal gene expression by regulating the accessibility of DNA regulatory elements. Using the Drosophila wing, we demonstrate that temporal changes in gene expression are accompanied by genome-wide changes in chromatin accessibility at temporal-specific enhancers. We also uncover a temporal cascade of transcription factors following a pulse of the steroid hormone ecdysone such that different times in wing development can be defined by distinct combinations of hormone-induced transcription factors. Finally, we show that the ecdysone-induced transcription factor E93 controls temporal identity by directly regulating chromatin accessibility across the genome. Notably, we found that E93 controls enhancer activity through three different modalities, including promoting accessibility of late-acting enhancers and decreasing accessibility of early-acting enhancers. Together, this work supports a model in which an extrinsic signal triggers an intrinsic transcription factor cascade that drives development forward in time through regulation of chromatin accessibility. PMID:28536147

Emerging Use of Gene Expression Microarrays in Plant Physiology

DOE PAGES

Wullschleger, Stan D.; Difazio, Stephen P.

2003-01-01

Microarrays have become an important technology for the global analysis of gene expression in humans, animals, plants, and microbes. Implemented in the context of a well-designed experiment, cDNA and oligonucleotide arrays can provide highthroughput, simultaneous analysis of transcript abundance for hundreds, if not thousands, of genes. However, despite widespread acceptance, the use of microarrays as a tool to better understand processes of interest to the plant physiologist is still being explored. To help illustrate current uses of microarrays in the plant sciences, several case studies that we believe demonstrate the emerging application of gene expression arrays in plant physiology weremore » selected from among the many posters and presentations at the 2003 Plant and Animal Genome XI Conference. Based on this survey, microarrays are being used to assess gene expression in plants exposed to the experimental manipulation of air temperature, soil water content and aluminium concentration in the root zone. Analysis often includes characterizing transcript profiles for multiple post-treatment sampling periods and categorizing genes with common patterns of response using hierarchical clustering techniques. In addition, microarrays are also providing insights into developmental changes in gene expression associated with fibre and root elongation in cotton and maize, respectively. Technical and analytical limitations of microarrays are discussed and projects attempting to advance areas of microarray design and data analysis are highlighted. Finally, although much work remains, we conclude that microarrays are a valuable tool for the plant physiologist interested in the characterization and identification of individual genes and gene families with potential application in the fields of agriculture, horticulture and forestry.« less

An Integrative Genetics Approach to Identify Candidate Genes Regulating BMD: Combining Linkage, Gene Expression, and Association

PubMed Central

Farber, Charles R; van Nas, Atila; Ghazalpour, Anatole; Aten, Jason E; Doss, Sudheer; Sos, Brandon; Schadt, Eric E; Ingram-Drake, Leslie; Davis, Richard C; Horvath, Steve; Smith, Desmond J; Drake, Thomas A; Lusis, Aldons J

2009-01-01

Numerous quantitative trait loci (QTLs) affecting bone traits have been identified in the mouse; however, few of the underlying genes have been discovered. To improve the process of transitioning from QTL to gene, we describe an integrative genetics approach, which combines linkage analysis, expression QTL (eQTL) mapping, causality modeling, and genetic association in outbred mice. In C57BL/6J × C3H/HeJ (BXH) F2 mice, nine QTLs regulating femoral BMD were identified. To select candidate genes from within each QTL region, microarray gene expression profiles from individual F2 mice were used to identify 148 genes whose expression was correlated with BMD and regulated by local eQTLs. Many of the genes that were the most highly correlated with BMD have been previously shown to modulate bone mass or skeletal development. Candidates were further prioritized by determining whether their expression was predicted to underlie variation in BMD. Using network edge orienting (NEO), a causality modeling algorithm, 18 of the 148 candidates were predicted to be causally related to differences in BMD. To fine-map QTLs, markers in outbred MF1 mice were tested for association with BMD. Three chromosome 11 SNPs were identified that were associated with BMD within the Bmd11 QTL. Finally, our approach provides strong support for Wnt9a, Rasd1, or both underlying Bmd11. Integration of multiple genetic and genomic data sets can substantially improve the efficiency of QTL fine-mapping and candidate gene identification. PMID:18767929

Uncovering the Role of RNA-Binding Proteins in Gene Expression in the Immune System

PubMed Central

Díaz-Muñoz, Manuel D.; Turner, Martin

2018-01-01

Fighting external pathogens requires an ever-changing immune system that relies on tight regulation of gene expression. Transcriptional control is the first step to build efficient responses while preventing immunodeficiencies and autoimmunity. Post-transcriptional regulation of RNA editing, location, stability, and translation are the other key steps for final gene expression, and they are all controlled by RNA-binding proteins (RBPs). Nowadays we have a deep understanding of how transcription factors control the immune system but recent evidences suggest that post-transcriptional regulation by RBPs is equally important for both development and activation of immune responses. Here, we review current knowledge about how post-transcriptional control by RBPs shapes our immune system and discuss the perspective of RBPs being the key players of a hidden immune cell epitranscriptome. PMID:29875770

Identification and validation of reference genes for quantification of target gene expression with quantitative real-time PCR for tall fescue under four abiotic stresses.

PubMed

Yang, Zhimin; Chen, Yu; Hu, Baoyun; Tan, Zhiqun; Huang, Bingru

2015-01-01

Tall fescue (Festuca arundinacea Schreb.) is widely utilized as a major forage and turfgrass species in the temperate regions of the world and is a valuable plant material for studying molecular mechanisms of grass stress tolerance due to its superior drought and heat tolerance among cool-season species. Selection of suitable reference genes for quantification of target gene expression is important for the discovery of molecular mechanisms underlying improved growth traits and stress tolerance. The stability of nine potential reference genes (ACT, TUB, EF1a, GAPDH, SAND, CACS, F-box, PEPKR1 and TIP41) was evaluated using four programs, GeNorm, NormFinder, BestKeeper, and RefFinder. The combinations of SAND and TUB or TIP41 and TUB were most stably expressed in salt-treated roots or leaves. The combinations of GAPDH with TIP41 or TUB were stable in roots and leaves under drought stress. TIP41 and PEPKR1 exhibited stable expression in cold-treated roots, and the combination of F-box, TIP41 and TUB was also stable in cold-treated leaves. CACS and TUB were the two most stable reference genes in heat-stressed roots. TIP41 combined with TUB and ACT was stably expressed in heat-stressed leaves. Finally, quantitative real-time polymerase chain reaction (qRT-PCR) assays of the target gene FaWRKY1 using the identified most stable reference genes confirmed the reliability of selected reference genes. The selection of suitable reference genes in tall fescue will allow for more accurate identification of stress-tolerance genes and molecular mechanisms conferring stress tolerance in this stress-tolerant species.

Gene Expression (mRNA) Markers for Differentiating between Malignant and Benign Follicular Thyroid Tumours

PubMed Central

Wojtas, Bartosz; Pfeifer, Aleksandra; Oczko-Wojciechowska, Malgorzata; Krajewska, Jolanta; Czarniecka, Agnieszka; Kukulska, Aleksandra; Eszlinger, Markus; Musholt, Thomas; Stokowy, Tomasz; Swierniak, Michal; Stobiecka, Ewa; Chmielik, Ewa; Rusinek, Dagmara; Tyszkiewicz, Tomasz; Halczok, Monika; Hauptmann, Steffen; Lange, Dariusz; Jarzab, Michal; Paschke, Ralf; Jarzab, Barbara

2017-01-01

Distinguishing between follicular thyroid cancer (FTC) and follicular thyroid adenoma (FTA) constitutes a long-standing diagnostic problem resulting in equivocal histopathological diagnoses. There is therefore a need for additional molecular markers. To identify molecular differences between FTC and FTA, we analyzed the gene expression microarray data of 52 follicular neoplasms. We also performed a meta-analysis involving 14 studies employing high throughput methods (365 follicular neoplasms analyzed). Based on these two analyses, we selected 18 genes differentially expressed between FTA and FTC. We validated them by quantitative real-time polymerase chain reaction (qRT-PCR) in an independent set of 71 follicular neoplasms from formaldehyde-fixed paraffin embedded (FFPE) tissue material. We confirmed differential expression for 7 genes (CPQ, PLVAP, TFF3, ACVRL1, ZFYVE21, FAM189A2, and CLEC3B). Finally, we created a classifier that distinguished between FTC and FTA with an accuracy of 78%, sensitivity of 76%, and specificity of 80%, based on the expression of 4 genes (CPQ, PLVAP, TFF3, ACVRL1). In our study, we have demonstrated that meta-analysis is a valuable method for selecting possible molecular markers. Based on our results, we conclude that there might exist a plausible limit of gene classifier accuracy of approximately 80%, when follicular tumors are discriminated based on formalin-fixed postoperative material. PMID:28574441

Gene Expression (mRNA) Markers for Differentiating between Malignant and Benign Follicular Thyroid Tumours.

PubMed

Wojtas, Bartosz; Pfeifer, Aleksandra; Oczko-Wojciechowska, Malgorzata; Krajewska, Jolanta; Czarniecka, Agnieszka; Kukulska, Aleksandra; Eszlinger, Markus; Musholt, Thomas; Stokowy, Tomasz; Swierniak, Michal; Stobiecka, Ewa; Chmielik, Ewa; Rusinek, Dagmara; Tyszkiewicz, Tomasz; Halczok, Monika; Hauptmann, Steffen; Lange, Dariusz; Jarzab, Michal; Paschke, Ralf; Jarzab, Barbara

2017-06-02

Distinguishing between follicular thyroid cancer (FTC) and follicular thyroid adenoma (FTA) constitutes a long-standing diagnostic problem resulting in equivocal histopathological diagnoses. There is therefore a need for additional molecular markers. To identify molecular differences between FTC and FTA, we analyzed the gene expression microarray data of 52 follicular neoplasms. We also performed a meta-analysis involving 14 studies employing high throughput methods (365 follicular neoplasms analyzed). Based on these two analyses, we selected 18 genes differentially expressed between FTA and FTC. We validated them by quantitative real-time polymerase chain reaction (qRT-PCR) in an independent set of 71 follicular neoplasms from formaldehyde-fixed paraffin embedded (FFPE) tissue material. We confirmed differential expression for 7 genes ( CPQ , PLVAP , TFF3 , ACVRL1 , ZFYVE21 , FAM189A2 , and CLEC3B ). Finally, we created a classifier that distinguished between FTC and FTA with an accuracy of 78%, sensitivity of 76%, and specificity of 80%, based on the expression of 4 genes ( CPQ , PLVAP , TFF3 , ACVRL1 ). In our study, we have demonstrated that meta-analysis is a valuable method for selecting possible molecular markers. Based on our results, we conclude that there might exist a plausible limit of gene classifier accuracy of approximately 80%, when follicular tumors are discriminated based on formalin-fixed postoperative material.

Genome-wide identification and characterization of WRKY transcriptional factor family in apple and analysis of their responses to waterlogging and drought stress.

PubMed

Meng, Dong; Li, Yuanyuan; Bai, Yang; Li, Mingjun; Cheng, Lailiang

2016-06-01

As one of the largest transcriptional factor families in plants, WRKY genes play significant roles in various biotic and abiotic stress responses. Although the WRKY gene family has been characterized in a few plant species, the details remain largely unknown in the apple (Malus domestica Borkh.). In this study, we identified a total of 127 MdWRKYs from the apple genome, which were divided into four subgroups according to the WRKY domains and zinc finger motif. Most of them were mapped onto the apple's 17 chromosomes and were expressed in more than one tissue, including shoot tips, mature leaves, fruit and apple calli. We then contrasted WRKY expression patterns between calli grown in solid medium (control) and liquid medium (representing waterlogging stress) and found that 34 WRKY genes were differentially expressed between the two growing conditions. Finally, we determined the expression patterns of 10 selected WRKY genes in an apple rootstock, G41, in response to waterlogging and drought stress, which identified candidate genes involved in responses to water stress for functional analysis. Our data provide interesting candidate MdWRKYs for future functional analysis and demonstrate that apple callus is a useful system for characterizing gene expression and function in apple. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Gene Expression Analysis Reveals New Possible Mechanisms of Vancomycin-Induced Nephrotoxicity and Identifies Gene Markers Candidates

PubMed Central

Dieterich, Christine; Puey, Angela; Lyn, Sylvia; Swezey, Robert; Furimsky, Anna; Fairchild, David; Mirsalis, Jon C.; Ng, Hanna H.

2009-01-01

Vancomycin, one of few effective treatments against methicillin-resistant Staphylococcus aureus, is nephrotoxic. The goals of this study were to (1) gain insights into molecular mechanisms of nephrotoxicity at the genomic level, (2) evaluate gene markers of vancomycin-induced kidney injury, and (3) compare gene expression responses after iv and ip administration. Groups of six female BALB/c mice were treated with seven daily iv or ip doses of vancomycin (50, 200, and 400 mg/kg) or saline, and sacrificed on day 8. Clinical chemistry and histopathology demonstrated kidney injury at 400 mg/kg only. Hierarchical clustering analysis revealed that kidney gene expression profiles of all mice treated at 400 mg/kg clustered with those of mice administered 200 mg/kg iv. Transcriptional profiling might thus be more sensitive than current clinical markers for detecting kidney damage, though the profiles can differ with the route of administration. Analysis of transcripts whose expression was changed by at least twofold compared with vehicle saline after high iv and ip doses of vancomycin suggested the possibility of oxidative stress and mitochondrial damage in vancomycin-induced toxicity. In addition, our data showed changes in expression of several transcripts from the complement and inflammatory pathways. Such expression changes were confirmed by relative real-time reverse transcription–polymerase chain reaction. Finally, our results further substantiate the use of gene markers of kidney toxicity such as KIM-1/Havcr1, as indicators of renal injury. PMID:18930951

Gene expression analysis reveals new possible mechanisms of vancomycin-induced nephrotoxicity and identifies gene markers candidates.

PubMed

Dieterich, Christine; Puey, Angela; Lin, Sylvia; Lyn, Sylvia; Swezey, Robert; Furimsky, Anna; Fairchild, David; Mirsalis, Jon C; Ng, Hanna H

2009-01-01

Vancomycin, one of few effective treatments against methicillin-resistant Staphylococcus aureus, is nephrotoxic. The goals of this study were to (1) gain insights into molecular mechanisms of nephrotoxicity at the genomic level, (2) evaluate gene markers of vancomycin-induced kidney injury, and (3) compare gene expression responses after iv and ip administration. Groups of six female BALB/c mice were treated with seven daily iv or ip doses of vancomycin (50, 200, and 400 mg/kg) or saline, and sacrificed on day 8. Clinical chemistry and histopathology demonstrated kidney injury at 400 mg/kg only. Hierarchical clustering analysis revealed that kidney gene expression profiles of all mice treated at 400 mg/kg clustered with those of mice administered 200 mg/kg iv. Transcriptional profiling might thus be more sensitive than current clinical markers for detecting kidney damage, though the profiles can differ with the route of administration. Analysis of transcripts whose expression was changed by at least twofold compared with vehicle saline after high iv and ip doses of vancomycin suggested the possibility of oxidative stress and mitochondrial damage in vancomycin-induced toxicity. In addition, our data showed changes in expression of several transcripts from the complement and inflammatory pathways. Such expression changes were confirmed by relative real-time reverse transcription-polymerase chain reaction. Finally, our results further substantiate the use of gene markers of kidney toxicity such as KIM-1/Havcr1, as indicators of renal injury.

Necdin, a Prader-Willi syndrome candidate gene, regulates gonadotropin-releasing hormone neurons during development.

PubMed

Miller, Nichol L G; Wevrick, Rachel; Mellon, Pamela L

2009-01-15

Prader-Willi syndrome (PWS) is a complex genetic disorder characterized by hyperphagia, obesity and hypogonadotrophic hypogonadism, all highly suggestive of hypothalamic dysfunction. The NDN gene, encoding the MAGE family protein, necdin, maps to the PWS chromosome region and is highly expressed in mature hypothalamic neurons. Adult mice lacking necdin have reduced numbers of gonadotropin-releasing hormone (GnRH) neurons, but the mechanism for this reduction is unknown. Herein, we show that, although necdin is not expressed in an immature, migratory GnRH neuronal cell line (GN11), high levels are present in a mature GnRH neuronal cell line (GT1-7). Furthermore, overexpression of necdin activates GnRH transcription through cis elements bound by the homeodomain repressor Msx that are located in the enhancer and promoter of the GnRH gene, and knock-down of necdin expression reduces GnRH gene expression. In fact, overexpression of Necdin relieves Msx repression of GnRH transcription through these elements and necdin co-immunoprecipitates with Msx from GnRH neuronal cells, indicating that necdin may activate GnRH gene expression by preventing repression of GnRH gene expression by Msx. Finally, necdin is necessary for generation of the full complement of GnRH neurons during mouse development and extension of GnRH axons to the median eminence. Together, these results indicate that lack of necdin during development likely contributes to the hypogonadotrophic hypogonadal phenotype in individuals with PWS.

Necdin, a Prader–Willi syndrome candidate gene, regulates gonadotropin-releasing hormone neurons during development

PubMed Central

Miller, Nichol L.G.; Wevrick, Rachel; Mellon, Pamela L.

2009-01-01

Prader–Willi syndrome (PWS) is a complex genetic disorder characterized by hyperphagia, obesity and hypogonadotrophic hypogonadism, all highly suggestive of hypothalamic dysfunction. The NDN gene, encoding the MAGE family protein, necdin, maps to the PWS chromosome region and is highly expressed in mature hypothalamic neurons. Adult mice lacking necdin have reduced numbers of gonadotropin-releasing hormone (GnRH) neurons, but the mechanism for this reduction is unknown. Herein, we show that, although necdin is not expressed in an immature, migratory GnRH neuronal cell line (GN11), high levels are present in a mature GnRH neuronal cell line (GT1-7). Furthermore, overexpression of necdin activates GnRH transcription through cis elements bound by the homeodomain repressor Msx that are located in the enhancer and promoter of the GnRH gene, and knock-down of necdin expression reduces GnRH gene expression. In fact, overexpression of Necdin relieves Msx repression of GnRH transcription through these elements and necdin co-immunoprecipitates with Msx from GnRH neuronal cells, indicating that necdin may activate GnRH gene expression by preventing repression of GnRH gene expression by Msx. Finally, necdin is necessary for generation of the full complement of GnRH neurons during mouse development and extension of GnRH axons to the median eminence. Together, these results indicate that lack of necdin during development likely contributes to the hypogonadotrophic hypogonadal phenotype in individuals with PWS. PMID:18930956

Identification and expression profiling analysis of TCP family genes involved in growth and development in maize.

PubMed

Chai, Wenbo; Jiang, Pengfei; Huang, Guoyu; Jiang, Haiyang; Li, Xiaoyu

2017-10-01

The TCP family is a group of plant-specific transcription factors. TCP genes encode proteins harboring bHLH structure, which is implicated in DNA binding and protein-protein interactions and known as the TCP domain. TCP genes play important roles in plant development and have been evolutionarily and functionally elaborated in various plants, however, no overall phylogenetic analysis or expression profiling of TCP genes in Zea mays has been reported. In the present study, a systematic analysis of molecular evolution and functional prediction of TCP family genes in maize ( Z . mays L.) has been conducted. We performed a genome-wide survey of TCP genes in maize, revealing the gene structure, chromosomal location and phylogenetic relationship of family members. Microsynteny between grass species and tissue-specific expression profiles were also investigated. In total, 29 TCP genes were identified in the maize genome, unevenly distributed on the 10 maize chromosomes. Additionally, ZmTCP genes were categorized into nine classes based on phylogeny and purifying selection may largely be responsible for maintaining the functions of maize TCP genes. What's more, microsynteny analysis suggested that TCP genes have been conserved during evolution. Finally, expression analysis revealed that most TCP genes are expressed in the stem and ear, which suggests that ZmTCP genes influence stem and ear growth. This result is consistent with the previous finding that maize TCP genes represses the growth of axillary organs and enables the formation of female inflorescences. Altogether, this study presents a thorough overview of TCP family in maize and provides a new perspective on the evolution of this gene family. The results also indicate that TCP family genes may be involved in development stage in plant growing conditions. Additionally, our results will be useful for further functional analysis of the TCP gene family in maize.

Identification of a core set of rhizobial infection genes using data from single cell-types.

PubMed

Chen, Da-Song; Liu, Cheng-Wu; Roy, Sonali; Cousins, Donna; Stacey, Nicola; Murray, Jeremy D

2015-01-01

Genome-wide expression studies on nodulation have varied in their scale from entire root systems to dissected nodules or root sections containing nodule primordia (NP). More recently efforts have focused on developing methods for isolation of root hairs from infected plants and the application of laser-capture microdissection technology to nodules. Here we analyze two published data sets to identify a core set of infection genes that are expressed in the nodule and in root hairs during infection. Among the genes identified were those encoding phenylpropanoid biosynthesis enzymes including Chalcone-O-Methyltransferase which is required for the production of the potent Nod gene inducer 4',4-dihydroxy-2-methoxychalcone. A promoter-GUS analysis in transgenic hairy roots for two genes encoding Chalcone-O-Methyltransferase isoforms revealed their expression in rhizobially infected root hairs and the nodule infection zone but not in the nitrogen fixation zone. We also describe a group of Rhizobially Induced Peroxidases whose expression overlaps with the production of superoxide in rhizobially infected root hairs and in nodules and roots. Finally, we identify a cohort of co-regulated transcription factors as candidate regulators of these processes.

Effects of hibernation on bone marrow transcriptome in thirteen-lined ground squirrels.

PubMed

Cooper, Scott T; Sell, Shawn S; Fahrenkrog, Molly; Wilkinson, Kory; Howard, David R; Bergen, Hannah; Cruz, Estefania; Cash, Steve E; Andrews, Matthew T; Hampton, Marshall

2016-07-01

Mammalian hibernators adapt to prolonged periods of immobility, hypometabolism, hypothermia, and oxidative stress, each capable of reducing bone marrow activity. In this study bone marrow transcriptomes were compared among thirteen-lined ground squirrels collected in July, winter torpor, and winter interbout arousal (IBA). The results were consistent with a suppression of acquired immune responses, and a shift to innate immune responses during hibernation through higher complement expression. Consistent with the increase in adipocytes found in bone marrow of hibernators, expression of genes associated with white adipose tissue are higher during hibernation. Genes that should strengthen the bone by increasing extracellular matrix were higher during hibernation, especially the collagen genes. Finally, expression of heat shock proteins were lower, and cold-response genes were higher, during hibernation. No differential expression of hematopoietic genes involved in erythrocyte or megakaryocyte production was observed. This global view of the changes in the bone marrow transcriptome over both short term (torpor vs. IBA) and long term (torpor vs. July) hypothermia can explain several observations made about circulating blood cells and the structure and strength of the bone during hibernation. Copyright © 2016 the American Physiological Society.

Hypothyroidism coordinately and transiently affects myelin protein gene expression in most rat brain regions during postnatal development.

PubMed

Ibarrola, N; Rodríguez-Peña, A

1997-03-28

To assess the role of thyroid hormone on myelin gene expression, we have studied the effect of hypothyroidism on the mRNA steady state levels for the major myelin protein genes: myelin basic protein (MBP), proteolipid protein (PLP), myelin-associated glycoprotein (MAG) and 2':3'-cyclic nucleotide 3'-phosphodiesterase (CNP) in different rat brain regions, during the first postnatal month. We found that hypothyroidism reduces the levels of every myelin protein transcript, with striking differences between the different brain regions. Thus, in the more caudal regions, the effect of hypothyroidism was extremely modest, being only evident at the earlier stages of myelination. In contrast, in the striatum and the cerebral cortex the important decrease in the myelin protein transcripts is maintained beyond the first postnatal month. Therefore, thyroid hormone modulates in a synchronous fashion the expression of the myelin genes and the length of its effect depends on the brain region. On the other hand, hyperthyroidism leads to an increase of the major myelin protein transcripts above control values. Finally, lack of thyroid hormone does not change the expression of the oligodendrocyte progenitor-specific gene, the platelet derived growth factor receptor alpha.

M-type 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase is the product of a late muscle differentiation gene.

PubMed

Vandoolaeghe, P; Gueuning, M A; Rousseau, G G

1999-06-07

Genes that are expressed in adult muscle, but not in myotubes, are useful markers of the last steps of muscle maturation. We have investigated at what stage of differentiation the muscle-specific (M) promoter of a gene that codes for 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFK2) becomes functional. M-PFK2 mRNA, which is present in adult muscle, did not appear during differentiation of L6 myoblasts into myotubes induced by growth factor withdrawal and hormonal treatment, even when this differentiation was stimulated by expression of transgenes coding for myf-5 or Rb. A comparison with the expression pattern of muscle genes showed that M-PFK2 is a marker of mature skeletal muscle. We also found that M-PFK2 is expressed in both types (slow-twitch and fast-twitch) of adult muscle. Thus, the M-PFK2 promoter is a novel model for studying the transcriptional control of the final steps of muscle differentiation that are common to the two types of myofibers. Copyright 1999 Academic Press.

PW1 gene/paternally expressed gene 3 (PW1/Peg3) identifies multiple adult stem and progenitor cell populations

PubMed Central

Besson, Vanessa; Smeriglio, Piera; Wegener, Amélie; Relaix, Frédéric; Nait Oumesmar, Brahim; Sassoon, David A.; Marazzi, Giovanna

2011-01-01

A variety of markers are invaluable for identifying and purifying stem/progenitor cells. Here we report the generation of a murine reporter line driven by Pw1 that reveals cycling and quiescent progenitor/stem cells in all adult tissues thus far examined, including the intestine, blood, testis, central nervous system, bone, skeletal muscle, and skin. Neurospheres generated from the adult PW1-reporter mouse show near 100% reporter-gene expression following a single passage. Furthermore, epidermal stem cells can be purified solely on the basis of reporter-gene expression. These cells are clonogenic, repopulate the epidermal stem-cell niches, and give rise to new hair follicles. Finally, we demonstrate that only PW1 reporter-expressing epidermal cells give rise to follicles that are capable of self-renewal following injury. Our data demonstrate that PW1 serves as an invaluable marker for competent self-renewing stem cells in a wide array of adult tissues, and the PW1-reporter mouse serves as a tool for rapid stem cell isolation and characterization. PMID:21709251

Macromolecular Crowding Regulates the Gene Expression Profile by Limiting Diffusion

DOE PAGES

Golkaram, Mahdi; Hellander, Stefan; Drawert, Brian; ...

2016-11-28

We seek to elucidate the role of macromolecular crowding in transcription and translation. It is well known that stochasticity in gene expression can lead to differential gene expression and heterogeneity in a cell population. Recent experimental observations by Tan et al. have improved our understanding of the functional role of macromolecular crowding. It can be inferred from their observations that macromolecular crowding can lead to robustness in gene expression, resulting in a more homogeneous cell population. We introduce a spatial stochastic model to provide insight into this process. Our results show that macromolecular crowding reduces noise (as measured by themore » kurtosis of the mRNA distribution) in a cell population by limiting the diffusion of transcription factors (i.e. removing the unstable intermediate states), and that crowding by large molecules reduces noise more efficiently than crowding by small molecules. Finally, our simulation results provide evidence that the local variation in chromatin density as well as the total volume exclusion of the chromatin in the nucleus can induce a homogenous cell population« less

Analysis of gene expression in a developmental context emphasizes distinct biological leitmotifs in human cancers

PubMed Central

Naxerova, Kamila; Bult, Carol J; Peaston, Anne; Fancher, Karen; Knowles, Barbara B; Kasif, Simon; Kohane, Isaac S

2008-01-01

Background In recent years, the molecular underpinnings of the long-observed resemblance between neoplastic and immature tissue have begun to emerge. Genome-wide transcriptional profiling has revealed similar gene expression signatures in several tumor types and early developmental stages of their tissue of origin. However, it remains unclear whether such a relationship is a universal feature of malignancy, whether heterogeneities exist in the developmental component of different tumor types and to which degree the resemblance between cancer and development is a tissue-specific phenomenon. Results We defined a developmental landscape by summarizing the main features of ten developmental time courses and projected gene expression from a variety of human tumor types onto this landscape. This comparison demonstrates a clear imprint of developmental gene expression in a wide range of tumors and with respect to different, even non-cognate developmental backgrounds. Our analysis reveals three classes of cancers with developmentally distinct transcriptional patterns. We characterize the biological processes dominating these classes and validate the class distinction with respect to a new time series of murine embryonic lung development. Finally, we identify a set of genes that are upregulated in most cancers and we show that this signature is active in early development. Conclusion This systematic and quantitative overview of the relationship between the neoplastic and developmental transcriptome spanning dozens of tissues provides a reliable outline of global trends in cancer gene expression, reveals potentially clinically relevant differences in the gene expression of different cancer types and represents a reference framework for interpretation of smaller-scale functional studies. PMID:18611264

Switch-like reprogramming of gene expression after fusion of multinucleate plasmodial cells of two Physarum polycephalum sporulation mutants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Walter, Pauline; Hoffmann, Xenia-Katharina; Ebeling, Britta

2013-05-24

Highlights: •We investigate reprogramming of gene expression in multinucleate single cells. •Cells of two differentiation control mutants are fused. •Fused cells proceed to alternative gene expression patterns. •The population of nuclei damps stochastic fluctuations in gene expression. •Dynamic processes of cellular reprogramming can be observed by repeated sampling of a cell. -- Abstract: Nonlinear dynamic processes involving the differential regulation of transcription factors are considered to impact the reprogramming of stem cells, germ cells, and somatic cells. Here, we fused two multinucleate plasmodial cells of Physarum polycephalum mutants defective in different sporulation control genes while being in different physiological states.more » The resulting heterokaryons established one of two significantly different expression patterns of marker genes while the plasmodial halves that were fused to each other synchronized spontaneously. Spontaneous synchronization suggests that switch-like control mechanisms spread over and finally control the entire plasmodium as a result of cytoplasmic mixing. Regulatory molecules due to the large volume of the vigorously streaming cytoplasm will define concentrations in acting on the population of nuclei and in the global setting of switches. Mixing of a large cytoplasmic volume is expected to damp stochasticity when individual nuclei deliver certain RNAs at low copy number into the cytoplasm. We conclude that spontaneous synchronization, the damping of molecular noise in gene expression by the large cytoplasmic volume, and the option to take multiple macroscopic samples from the same plasmodium provide unique options for studying the dynamics of cellular reprogramming at the single cell level.« less

Characterization and anti-inflammation role of swine IFITM3 gene

PubMed Central

Li, He-Ping; Chen, Pei-Ge; Liu, Fu-Tao; Zhu, He-Shui; Jiao, Xian-Qin; Zhong, Kai; Guo, Yu-Jie; Zha, Guang-Ming; Han, Li-Qiang; Lu, Wei-Fei; Wang, Yue-Ying; Yang, Guo-Yu

2017-01-01

IFITM3 is involved in cell adhesion, apoptosis, immune, and antivirus activity. Furthermore, IFITM3 gene has been considered as a preferential marker for inflammatory diseases, and positive correlation to pathological grades. Therefore, we assumed that IFITM3 was regulated by different signal pathways. To better understand IFITM3 function in inflammatory response, we cloned swine IFITM3 gene, and detected IFITM3 distribution in tissues, as well as characterized this gene. Results indicated that the length of swine IFITM3 gene was 438 bp, encoding 145 amino acids. IFITM3 gene expression abundance was higher in spleen and lungs. Moreover, we next constructed the eukaryotic expression vector PBIFM3 and transfected into PK15 cells, finally obtained swine IFITM3 gene stable expression cell line. Meanwhile, we explored the effects of LPS on swine IFITM3 expression. Results showed that LPS increased IFITM3 mRNA abundance and exhibited time-dependent effect for LPS treatment. To further demonstrate the mechanism that IFITM3 regulated type I IFNs production, we also detected the important molecules expression of TLR4 signaling pathway. In transfected and non-transfected IFITM3 PK15 cells, LPS exacerbated the relative expression of TLR4-NFκB signaling molecules. However, the IFITM3 overexpression suppressed the inflammatory development of PK15 cells. In conclusion, these data indicated that the overexpression of swine IFITM3 could decrease the inflammatory response through TLR4 signaling pathway, and participate in type I interferon production. These findings may lead to an improved understanding of the biological function of IFITM3 in inflammation. PMID:29088728

Human growth is associated with distinct patterns of gene expression in evolutionarily conserved networks

PubMed Central

2013-01-01

Background A co-ordinated tissue-independent gene expression profile associated with growth is present in rodent models and this is hypothesised to extend to all mammals. Growth in humans has similarities to other mammals but the return to active long bone growth in the pubertal growth spurt is a distinctly human growth event. The aim of this study was to describe gene expression and biological pathways associated with stages of growth in children and to assess tissue-independent expression patterns in relation to human growth. Results We conducted gene expression analysis on a library of datasets from normal children with age annotation, collated from the NCBI Gene Expression Omnibus (GEO) and EBI Arrayexpress databases. A primary data set was generated using cells of lymphoid origin from normal children; the expression of 688 genes (ANOVA false discovery rate modified p-value, q < 0.1) was associated with age, and subsets of these genes formed clusters that correlated with the phases of growth – infancy, childhood, puberty and final height. Network analysis on these clusters identified evolutionarily conserved growth pathways (NOTCH, VEGF, TGFB, WNT and glucocorticoid receptor – Hyper-geometric test, q < 0.05). The greatest degree of network ‘connectivity’ and hence functional significance was present in infancy (Wilcoxon test, p < 0.05), which then decreased through to adulthood. These observations were confirmed in a separate validation data set from lymphoid tissue. Similar biological pathways were observed to be associated with development-related gene expression in other tissues (conjunctival epithelia, temporal lobe brain tissue and bone marrow) suggesting the existence of a tissue-independent genetic program for human growth and maturation. Conclusions Similar evolutionarily conserved pathways have been associated with gene expression and child growth in multiple tissues. These expression profiles associate with the developmental phases of growth including the return to active long bone growth in puberty, a distinctly human event. These observations also have direct medical relevance to pathological changes that induce disease in children. Taking into account development-dependent gene expression profiles for normal children will be key to the appropriate selection of genes and pathways as potential biomarkers of disease or as drug targets. PMID:23941278

Estimating differential expression from multiple indicators

PubMed Central

Ilmjärv, Sten; Hundahl, Christian Ansgar; Reimets, Riin; Niitsoo, Margus; Kolde, Raivo; Vilo, Jaak; Vasar, Eero; Luuk, Hendrik

2014-01-01

Regardless of the advent of high-throughput sequencing, microarrays remain central in current biomedical research. Conventional microarray analysis pipelines apply data reduction before the estimation of differential expression, which is likely to render the estimates susceptible to noise from signal summarization and reduce statistical power. We present a probe-level framework, which capitalizes on the high number of concurrent measurements to provide more robust differential expression estimates. The framework naturally extends to various experimental designs and target categories (e.g. transcripts, genes, genomic regions) as well as small sample sizes. Benchmarking in relation to popular microarray and RNA-sequencing data-analysis pipelines indicated high and stable performance on the Microarray Quality Control dataset and in a cell-culture model of hypoxia. Experimental-data-exhibiting long-range epigenetic silencing of gene expression was used to demonstrate the efficacy of detecting differential expression of genomic regions, a level of analysis not embraced by conventional workflows. Finally, we designed and conducted an experiment to identify hypothermia-responsive genes in terms of monotonic time-response. As a novel insight, hypothermia-dependent up-regulation of multiple genes of two major antioxidant pathways was identified and verified by quantitative real-time PCR. PMID:24586062

Generation of 2A-linked multicistronic cassettes by recombinant PCR.

PubMed

Szymczak-Workman, Andrea L; Vignali, Kate M; Vignali, Dario A A

2012-02-01

The need for reliable, multicistronic vectors for multigene delivery is at the forefront of biomedical technology. It is now possible to express multiple proteins from a single open reading frame (ORF) using 2A peptide-linked multicistronic vectors. These small sequences, when cloned between genes, allow for efficient, stoichiometric production of discrete protein products within a single vector through a novel "cleavage" event within the 2A peptide sequence. Expression of more than two genes using conventional approaches has several limitations, most notably imbalanced protein expression and large size. The use of 2A peptide sequences alleviates these concerns. They are small (18-22 amino acids) and have divergent amino-terminal sequences, which minimizes the chance for homologous recombination and allows for multiple, different 2A peptide sequences to be used within a single vector. Importantly, separation of genes placed between 2A peptide sequences is nearly 100%, which allows for stoichiometric and concordant expression of the genes, regardless of the order of placement within the vector. This protocol describes the use of recombinant polymerase chain reaction (PCR) to connect multiple 2A-linked protein sequences. The final construct is subcloned into an expression vector.

Integrated analysis of microRNA and gene expression profiles reveals a functional regulatory module associated with liver fibrosis.

PubMed

Chen, Wei; Zhao, Wenshan; Yang, Aiting; Xu, Anjian; Wang, Huan; Cong, Min; Liu, Tianhui; Wang, Ping; You, Hong

2017-12-15

Liver fibrosis, characterized with the excessive accumulation of extracellular matrix (ECM) proteins, represents the final common pathway of chronic liver inflammation. Ever-increasing evidence indicates microRNAs (miRNAs) dysregulation has important implications in the different stages of liver fibrosis. However, our knowledge of miRNA-gene regulation details pertaining to such disease remains unclear. The publicly available Gene Expression Omnibus (GEO) datasets of patients suffered from cirrhosis were extracted for integrated analysis. Differentially expressed miRNAs (DEMs) and genes (DEGs) were identified using GEO2R web tool. Putative target gene prediction of DEMs was carried out using the intersection of five major algorithms: DIANA-microT, TargetScan, miRanda, PICTAR5 and miRWalk. Functional miRNA-gene regulatory network (FMGRN) was constructed based on the computational target predictions at the sequence level and the inverse expression relationships between DEMs and DEGs. DAVID web server was selected to perform KEGG pathway enrichment analysis. Functional miRNA-gene regulatory module was generated based on the biological interpretation. Internal connections among genes in liver fibrosis-related module were determined using String database. MiRNA-gene regulatory modules related to liver fibrosis were experimentally verified in recombinant human TGFβ1 stimulated and specific miRNA inhibitor treated LX-2 cells. We totally identified 85 and 923 dysregulated miRNAs and genes in liver cirrhosis biopsy samples compared to their normal controls. All evident miRNA-gene pairs were identified and assembled into FMGRN which consisted of 990 regulations between 51 miRNAs and 275 genes, forming two big sub-networks that were defined as down-network and up-network, respectively. KEGG pathway enrichment analysis revealed that up-network was prominently involved in several KEGG pathways, in which "Focal adhesion", "PI3K-Akt signaling pathway" and "ECM-receptor interaction" were remarked significant (adjusted p<0.001). Genes enriched in these pathways coupled with their regulatory miRNAs formed a functional miRNA-gene regulatory module that contains 7 miRNAs, 22 genes and 42 miRNA-gene connections. Gene interaction analysis based on String database revealed that 8 out of 22 genes were highly clustered. Finally, we experimentally confirmed a functional regulatory module containing 5 miRNAs (miR-130b-3p, miR-148a-3p, miR-345-5p, miR-378a-3p, and miR-422a) and 6 genes (COL6A1, COL6A2, COL6A3, PIK3R3, COL1A1, CCND2) associated with liver fibrosis. Our integrated analysis of miRNA and gene expression profiles highlighted a functional miRNA-gene regulatory module associated with liver fibrosis, which, to some extent, may provide important clues to better understand the underlying pathogenesis of liver fibrosis. Copyright © 2017. Published by Elsevier B.V.

Identification of differentially expressed genes in the oviduct of two rabbit lines divergently selected for uterine capacity using suppression subtractive hybridization.

PubMed

Ballester, M; Castelló, A; Peiró, R; Argente, M J; Santacreu, M A; Folch, J M

2013-06-01

Suppressive subtractive hybridization libraries from oviduct at 62 h post-mating of two lines of rabbits divergently selected for uterine capacity were generated to identify differentially expressed genes. A total of 438 singletons and 126 contigs were obtained by cluster assembly and sequence alignment of 704 expressed sequence tags (ESTs), of which 54% showed homology to known proteins of the non-redundant NCBI databases. Differential screening by dot blot validated 71 ESTs, of which 47 showed similarity to known genes. Transcripts of genes were functionally annotated in the molecular function and the biological process gene ontology categories using the BLAST2GO software and were assigned to reproductive developmental process, immune response, amino acid metabolism and degradation, response to stress and apoptosis terms. Finally, three interesting genes, PGR, HSD17B4 and ERO1L, were identified as overexpressed in the low line using RT-qPCR. Our study provides a list of candidate genes that can be useful to understanding the molecular mechanisms underlying the phenotypic differences observed in early embryo survival and development traits. © 2012 The Authors, Animal Genetics © 2012 Stichting International Foundation for Animal Genetics.

Identification and Analysis of the Biosynthetic Gene Cluster Encoding the Thiopeptide Antibiotic Cyclothiazomycin in Streptomyces hygroscopicus 10-22▿ †

PubMed Central

Wang, Jiang; Yu, Yi; Tang, Kexuan; Liu, Wen; He, Xinyi; Huang, Xi; Deng, Zixin

2010-01-01

Thiopeptide antibiotics are an important class of natural products resulting from posttranslational modifications of ribosomally synthesized peptides. Cyclothiazomycin is a typical thiopeptide antibiotic that has a unique bridged macrocyclic structure derived from an 18-amino-acid structural peptide. Here we reported cloning, sequencing, and heterologous expression of the cyclothiazomycin biosynthetic gene cluster from Streptomyces hygroscopicus 10-22. Remarkably, successful heterologous expression of a 22.7-kb gene cluster in Streptomyces lividans 1326 suggested that there is a minimum set of 15 open reading frames that includes all of the functional genes required for cyclothiazomycin production. Six genes of these genes, cltBCDEFG flanking the structural gene cltA, were predicted to encode the enzymes required for the main framework of cyclothiazomycin, and two enzymes encoded by a putative operon, cltMN, were hypothesized to participate in the tailoring step to generate the tertiary thioether, leading to the final cyclization of the bridged macrocyclic structure. This rigorous bioinformatics analysis based on heterologous expression of cyclothiazomycin resulted in an ideal biosynthetic model for us to understand the biosynthesis of thiopeptides. PMID:20154110

MiRNA-TF-gene network analysis through ranking of biomolecules for multi-informative uterine leiomyoma dataset.

PubMed

Mallik, Saurav; Maulik, Ujjwal

2015-10-01

Gene ranking is an important problem in bioinformatics. Here, we propose a new framework for ranking biomolecules (viz., miRNAs, transcription-factors/TFs and genes) in a multi-informative uterine leiomyoma dataset having both gene expression and methylation data using (statistical) eigenvector centrality based approach. At first, genes that are both differentially expressed and methylated, are identified using Limma statistical test. A network, comprising these genes, corresponding TFs from TRANSFAC and ITFP databases, and targeter miRNAs from miRWalk database, is then built. The biomolecules are then ranked based on eigenvector centrality. Our proposed method provides better average accuracy in hub gene and non-hub gene classifications than other methods. Furthermore, pre-ranked Gene set enrichment analysis is applied on the pathway database as well as GO-term databases of Molecular Signatures Database with providing a pre-ranked gene-list based on different centrality values for comparing among the ranking methods. Finally, top novel potential gene-markers for the uterine leiomyoma are provided. Copyright © 2015 Elsevier Inc. All rights reserved.

Distal-less regulates eyespot patterns and melanization in Bicyclus butterflies.

PubMed

Monteiro, Antónia; Chen, Bin; Ramos, Diane M; Oliver, Jeffrey C; Tong, Xiaoling; Guo, Min; Wang, Wen-Kai; Fazzino, Lisa; Kamal, Firdous

2013-07-01

Butterfly eyespots represent novel complex traits that display substantial diversity in number and size within and across species. Correlative gene expression studies have implicated a large suite of transcription factors, including Distal-less (Dll), Engrailed (En), and Spalt (Sal), in eyespot development in butterflies, but direct evidence testing the function of any of these proteins is still missing. Here we show that the characteristic two-eyespot pattern of wildtype Bicyclus anynana forewings is correlated with dynamic progression of Dll, En, and Sal expression in larval wings from four spots to two spots, whereas no such decline in gene expression ensues in a four-eyespot mutant. We then conduct transgenic experiments testing whether over-expression of any of these genes in a wild-type genetic background is sufficient to induce eyespot differentiation in these pre-patterned wing compartments. We also produce a Dll-RNAi transgenic line to test how Dll down-regulation affects eyespot development. Finally we test how ectopic expression of these genes during the pupal stages of development alters adults color patters. We show that over-expressing Dll in larvae is sufficient to induce the differentiation of additional eyespots and increase the size of eyespots, whereas down-regulating Dll leads to a decrease in eyespot size. Furthermore, ectopic expression of Dll in the early pupal wing led to the appearance of ectopic patches of black scales. We conclude that Dll is a positive regulator of focal differentiation and eyespot signaling and that this gene is also a possible selector gene for scale melanization in butterflies. Copyright © 2013 Wiley Periodicals, Inc.

Cancer stem cell-related gene expression as a potential biomarker of response for first-in-class imipridone ONC201 in solid tumors.

PubMed

Prabhu, Varun V; Lulla, Amriti R; Madhukar, Neel S; Ralff, Marie D; Zhao, Dan; Kline, Christina Leah B; Van den Heuvel, A Pieter J; Lev, Avital; Garnett, Mathew J; McDermott, Ultan; Benes, Cyril H; Batchelor, Tracy T; Chi, Andrew S; Elemento, Olivier; Allen, Joshua E; El-Deiry, Wafik S

2017-01-01

Cancer stem cells (CSCs) correlate with recurrence, metastasis and poor survival in clinical studies. Encouraging results from clinical trials of CSC inhibitors have further validated CSCs as therapeutic targets. ONC201 is a first-in-class small molecule imipridone in Phase I/II clinical trials for advanced cancer. We have previously shown that ONC201 targets self-renewing, chemotherapy-resistant colorectal CSCs via Akt/ERK inhibition and DR5/TRAIL induction. In this study, we demonstrate that the anti-CSC effects of ONC201 involve early changes in stem cell-related gene expression prior to tumor cell death induction. A targeted network analysis of gene expression profiles in colorectal cancer cells revealed that ONC201 downregulates stem cell pathways such as Wnt signaling and modulates genes (ID1, ID2, ID3 and ALDH7A1) known to regulate self-renewal in colorectal, prostate cancer and glioblastoma. ONC201-mediated changes in CSC-related gene expression were validated at the RNA and protein level for each tumor type. Accordingly, we observed inhibition of self-renewal and CSC markers in prostate cancer cell lines and patient-derived glioblastoma cells upon ONC201 treatment. Interestingly, ONC201-mediated CSC depletion does not occur in colorectal cancer cells with acquired resistance to ONC201. Finally, we observed that basal expression of CSC-related genes (ID1, CD44, HES7 and TCF3) significantly correlate with ONC201 efficacy in >1000 cancer cell lines and combining the expression of multiple genes leads to a stronger overall prediction. These proof-of-concept studies provide a rationale for testing CSC expression at the RNA and protein level as a predictive and pharmacodynamic biomarker of ONC201 response in ongoing clinical studies.

Cancer stem cell-related gene expression as a potential biomarker of response for first-in-class imipridone ONC201 in solid tumors

PubMed Central

Zhao, Dan; Kline, Christina Leah B.; Van den Heuvel, A. Pieter J.; Lev, Avital; Garnett, Mathew J.; McDermott, Ultan; Benes, Cyril H.; Batchelor, Tracy T.; Chi, Andrew S.; Elemento, Olivier; Allen, Joshua E.

2017-01-01

Cancer stem cells (CSCs) correlate with recurrence, metastasis and poor survival in clinical studies. Encouraging results from clinical trials of CSC inhibitors have further validated CSCs as therapeutic targets. ONC201 is a first-in-class small molecule imipridone in Phase I/II clinical trials for advanced cancer. We have previously shown that ONC201 targets self-renewing, chemotherapy-resistant colorectal CSCs via Akt/ERK inhibition and DR5/TRAIL induction. In this study, we demonstrate that the anti-CSC effects of ONC201 involve early changes in stem cell-related gene expression prior to tumor cell death induction. A targeted network analysis of gene expression profiles in colorectal cancer cells revealed that ONC201 downregulates stem cell pathways such as Wnt signaling and modulates genes (ID1, ID2, ID3 and ALDH7A1) known to regulate self-renewal in colorectal, prostate cancer and glioblastoma. ONC201-mediated changes in CSC-related gene expression were validated at the RNA and protein level for each tumor type. Accordingly, we observed inhibition of self-renewal and CSC markers in prostate cancer cell lines and patient-derived glioblastoma cells upon ONC201 treatment. Interestingly, ONC201-mediated CSC depletion does not occur in colorectal cancer cells with acquired resistance to ONC201. Finally, we observed that basal expression of CSC-related genes (ID1, CD44, HES7 and TCF3) significantly correlate with ONC201 efficacy in >1000 cancer cell lines and combining the expression of multiple genes leads to a stronger overall prediction. These proof-of-concept studies provide a rationale for testing CSC expression at the RNA and protein level as a predictive and pharmacodynamic biomarker of ONC201 response in ongoing clinical studies. PMID:28767654

Uterine Gene Expression in the Live-Bearing Lizard, Chalcides ocellatus, Reveals Convergence of Squamate Reptile and Mammalian Pregnancy Mechanisms

PubMed Central

Brandley, Matthew C.; Young, Rebecca L.; Warren, Dan L.; Thompson, Michael B.; Wagner, Günter P.

2012-01-01

Although the morphological and physiological changes involved in pregnancy in live-bearing reptiles are well studied, the genetic mechanisms that underlie these changes are not known. We used the viviparous African Ocellated Skink, Chalcides ocellatus, as a model to identify a near complete gene expression profile associated with pregnancy using RNA-Seq analyses of uterine transcriptomes. Pregnancy in C. ocellatus is associated with upregulation of uterine genes involved with metabolism, cell proliferation and death, and cellular transport. Moreover, there are clear parallels between the genetic processes associated with pregnancy in mammals and Chalcides in expression of genes related to tissue remodeling, angiogenesis, immune system regulation, and nutrient provisioning to the embryo. In particular, the pregnant uterine transcriptome is dominated by expression of proteolytic enzymes that we speculate are involved both with remodeling the chorioallantoic placenta and histotrophy in the omphaloplacenta. Elements of the maternal innate immune system are downregulated in the pregnant uterus, indicating a potential mechanism to avoid rejection of the embryo. We found a downregulation of major histocompatability complex loci and estrogen and progesterone receptors in the pregnant uterus. This pattern is similar to mammals but cannot be explained by the mammalian model. The latter finding provides evidence that pregnancy is controlled by different endocrinological mechanisms in mammals and reptiles. Finally, 88% of the identified genes are expressed in both the pregnant and the nonpregnant uterus, and thus, morphological and physiological changes associated with C. ocellatus pregnancy are likely a result of regulation of genes continually expressed in the uterus rather than the initiation of expression of unique genes. PMID:22333490

Gene expression studies of developing bovine longissimus muscle from two different beef cattle breeds

PubMed Central

Lehnert, Sigrid A; Reverter, Antonio; Byrne, Keren A; Wang, Yonghong; Nattrass, Greg S; Hudson, Nicholas J; Greenwood, Paul L

2007-01-01

Background The muscle fiber number and fiber composition of muscle is largely determined during prenatal development. In order to discover genes that are involved in determining adult muscle phenotypes, we studied the gene expression profile of developing fetal bovine longissimus muscle from animals with two different genetic backgrounds using a bovine cDNA microarray. Fetal longissimus muscle was sampled at 4 stages of myogenesis and muscle maturation: primary myogenesis (d 60), secondary myogenesis (d 135), as well as beginning (d 195) and final stages (birth) of functional differentiation of muscle fibers. All fetuses and newborns (total n = 24) were from Hereford dams and crossed with either Wagyu (high intramuscular fat) or Piedmontese (GDF8 mutant) sires, genotypes that vary markedly in muscle and compositional characteristics later in postnatal life. Results We obtained expression profiles of three individuals for each time point and genotype to allow comparisons across time and between sire breeds. Quantitative reverse transcription-PCR analysis of RNA from developing longissimus muscle was able to validate the differential expression patterns observed for a selection of differentially expressed genes, with one exception. We detected large-scale changes in temporal gene expression between the four developmental stages in genes coding for extracellular matrix and for muscle fiber structural and metabolic proteins. FSTL1 and IGFBP5 were two genes implicated in growth and differentiation that showed developmentally regulated expression levels in fetal muscle. An abundantly expressed gene with no functional annotation was found to be developmentally regulated in the same manner as muscle structural proteins. We also observed differences in gene expression profiles between the two different sire breeds. Wagyu-sired calves showed higher expression of fatty acid binding protein 5 (FABP5) RNA at birth. The developing longissimus muscle of fetuses carrying the Piedmontese mutation shows an emphasis on glycolytic muscle biochemistry and a large-scale up-regulation of the translational machinery at birth. We also document evidence for timing differences in differentiation events between the two breeds. Conclusion Taken together, these findings provide a detailed description of molecular events accompanying skeletal muscle differentiation in the bovine, as well as gene expression differences that may underpin the phenotype differences between the two breeds. In addition, this study has highlighted a non-coding RNA, which is abundantly expressed and developmentally regulated in bovine fetal muscle. PMID:17697390

DEEP--a tool for differential expression effector prediction.

PubMed

Degenhardt, Jost; Haubrock, Martin; Dönitz, Jürgen; Wingender, Edgar; Crass, Torsten

2007-07-01

High-throughput methods for measuring transcript abundance, like SAGE or microarrays, are widely used for determining differences in gene expression between different tissue types, dignities (normal/malignant) or time points. Further analysis of such data frequently aims at the identification of gene interaction networks that form the causal basis for the observed properties of the systems under examination. To this end, it is usually not sufficient to rely on the measured gene expression levels alone; rather, additional biological knowledge has to be taken into account in order to generate useful hypotheses about the molecular mechanism leading to the realization of a certain phenotype. We present a method that combines gene expression data with biological expert knowledge on molecular interaction networks, as described by the TRANSPATH database on signal transduction, to predict additional--and not necessarily differentially expressed--genes or gene products which might participate in processes specific for either of the examined tissues or conditions. In a first step, significance values for over-expression in tissue/condition A or B are assigned to all genes in the expression data set. Genes with a significance value exceeding a certain threshold are used as starting points for the reconstruction of a graph with signaling components as nodes and signaling events as edges. In a subsequent graph traversal process, again starting from the previously identified differentially expressed genes, all encountered nodes 'inherit' all their starting nodes' significance values. In a final step, the graph is visualized, the nodes being colored according to a weighted average of their inherited significance values. Each node's, or sub-network's, predominant color, ranging from green (significant for tissue/condition A) over yellow (not significant for either tissue/condition) to red (significant for tissue/condition B), thus gives an immediate visual clue on which molecules--differentially expressed or not--may play pivotal roles in the tissues or conditions under examination. The described method has been implemented in Java as a client/server application and a web interface called DEEP (Differential Expression Effector Prediction). The client, which features an easy-to-use graphical interface, can freely be downloaded from the following URL: http://deep.bioinf.med.uni-goettingen.de.

Reduction of adenovirus E1A mRNA by RNAi results in enhanced recombinant protein expression in transiently transfected HEK293 cells.

PubMed

Hacker, David L; Bertschinger, Martin; Baldi, Lucia; Wurm, Florian M

2004-10-27

Human embryonic kidney 293 (HEK293) cells, a widely used host for large-scale transient expression of recombinant proteins, are transformed with the adenovirus E1A and E1B genes. Because the E1A proteins function as transcriptional activators or repressors, they may have a positive or negative effect on transient transgene expression in this cell line. Suspension cultures of HEK293 EBNA (HEK293E) cells were co-transfected with a reporter plasmid expressing the GFP gene and a plasmid expressing a short hairpin RNA (shRNA) targeting the E1A mRNAs for degradation by RNA interference (RNAi). The presence of the shRNA in HEK293E cells reduced the steady state level of E1A mRNA up to 75% and increased transient GFP expression from either the elongation factor-1alpha (EF-1alpha) promoter or the human cytomegalovirus (HCMV) immediate early promoter up to twofold. E1A mRNA depletion also resulted in a twofold increase in transient expression of a recombinant IgG in both small- and large-scale suspension cultures when the IgG light and heavy chain genes were controlled by the EF-1alpha promoter. Finally, transient IgG expression was enhanced 2.5-fold when the anti-E1A shRNA was expressed from the same vector as the IgG light chain gene. These results demonstrated that E1A has a negative effect on transient gene expression in HEK293E cells, and they established that RNAi can be used to enhance recombinant protein expression in mammalian cells.

An integrated systems genetics screen reveals the transcriptional structure of inherited predisposition to metastatic disease

PubMed Central

Faraji, Farhoud; Hu, Ying; Wu, Gang; Goldberger, Natalie E.; Walker, Renard C.; Zhang, Jinghui; Hunter, Kent W.

2014-01-01

Metastasis is the result of stochastic genomic and epigenetic events leading to gene expression profiles that drive tumor dissemination. Here we exploit the principle that metastatic propensity is modified by the genetic background to generate prognostic gene expression signatures that illuminate regulators of metastasis. We also identify multiple microRNAs whose germline variation is causally linked to tumor progression and metastasis. We employ network analysis of global gene expression profiles in tumors derived from a panel of recombinant inbred mice to identify a network of co-expressed genes centered on Cnot2 that predicts metastasis-free survival. Modulating Cnot2 expression changes tumor cell metastatic potential in vivo, supporting a functional role for Cnot2 in metastasis. Small RNA sequencing of the same tumor set revealed a negative correlation between expression of the Mir216/217 cluster and tumor progression. Expression quantitative trait locus analysis (eQTL) identified cis-eQTLs at the Mir216/217 locus, indicating that differences in expression may be inherited. Ectopic expression of Mir216/217 in tumor cells suppressed metastasis in vivo. Finally, small RNA sequencing and mRNA expression profiling data were integrated to reveal that miR-3470a/b target a high proportion of network transcripts. In vivo analysis of Mir3470a/b demonstrated that both promote metastasis. Moreover, Mir3470b is a likely regulator of the Cnot2 network as its overexpression down-regulated expression of network hub genes and enhanced metastasis in vivo, phenocopying Cnot2 knockdown. The resulting data from this strategy identify Cnot2 as a novel regulator of metastasis and demonstrate the power of our systems-level approach in identifying modifiers of metastasis. PMID:24322557

Comprehensive analysis of transcriptome variation uncovers known and novel driver events in T-cell acute lymphoblastic leukemia.

PubMed

Atak, Zeynep Kalender; Gianfelici, Valentina; Hulselmans, Gert; De Keersmaecker, Kim; Devasia, Arun George; Geerdens, Ellen; Mentens, Nicole; Chiaretti, Sabina; Durinck, Kaat; Uyttebroeck, Anne; Vandenberghe, Peter; Wlodarska, Iwona; Cloos, Jacqueline; Foà, Robin; Speleman, Frank; Cools, Jan; Aerts, Stein

2013-01-01

RNA-seq is a promising technology to re-sequence protein coding genes for the identification of single nucleotide variants (SNV), while simultaneously obtaining information on structural variations and gene expression perturbations. We asked whether RNA-seq is suitable for the detection of driver mutations in T-cell acute lymphoblastic leukemia (T-ALL). These leukemias are caused by a combination of gene fusions, over-expression of transcription factors and cooperative point mutations in oncogenes and tumor suppressor genes. We analyzed 31 T-ALL patient samples and 18 T-ALL cell lines by high-coverage paired-end RNA-seq. First, we optimized the detection of SNVs in RNA-seq data by comparing the results with exome re-sequencing data. We identified known driver genes with recurrent protein altering variations, as well as several new candidates including H3F3A, PTK2B, and STAT5B. Next, we determined accurate gene expression levels from the RNA-seq data through normalizations and batch effect removal, and used these to classify patients into T-ALL subtypes. Finally, we detected gene fusions, of which several can explain the over-expression of key driver genes such as TLX1, PLAG1, LMO1, or NKX2-1; and others result in novel fusion transcripts encoding activated kinases (SSBP2-FER and TPM3-JAK2) or involving MLLT10. In conclusion, we present novel analysis pipelines for variant calling, variant filtering, and expression normalization on RNA-seq data, and successfully applied these for the detection of translocations, point mutations, INDELs, exon-skipping events, and expression perturbations in T-ALL.

Integrative multi-platform meta-analysis of gene expression profiles in pancreatic ductal adenocarcinoma patients for identifying novel diagnostic biomarkers.

PubMed

Irigoyen, Antonio; Jimenez-Luna, Cristina; Benavides, Manuel; Caba, Octavio; Gallego, Javier; Ortuño, Francisco Manuel; Guillen-Ponce, Carmen; Rojas, Ignacio; Aranda, Enrique; Torres, Carolina; Prados, Jose

2018-01-01

Applying differentially expressed genes (DEGs) to identify feasible biomarkers in diseases can be a hard task when working with heterogeneous datasets. Expression data are strongly influenced by technology, sample preparation processes, and/or labeling methods. The proliferation of different microarray platforms for measuring gene expression increases the need to develop models able to compare their results, especially when different technologies can lead to signal values that vary greatly. Integrative meta-analysis can significantly improve the reliability and robustness of DEG detection. The objective of this work was to develop an integrative approach for identifying potential cancer biomarkers by integrating gene expression data from two different platforms. Pancreatic ductal adenocarcinoma (PDAC), where there is an urgent need to find new biomarkers due its late diagnosis, is an ideal candidate for testing this technology. Expression data from two different datasets, namely Affymetrix and Illumina (18 and 36 PDAC patients, respectively), as well as from 18 healthy controls, was used for this study. A meta-analysis based on an empirical Bayesian methodology (ComBat) was then proposed to integrate these datasets. DEGs were finally identified from the integrated data by using the statistical programming language R. After our integrative meta-analysis, 5 genes were commonly identified within the individual analyses of the independent datasets. Also, 28 novel genes that were not reported by the individual analyses ('gained' genes) were also discovered. Several of these gained genes have been already related to other gastroenterological tumors. The proposed integrative meta-analysis has revealed novel DEGs that may play an important role in PDAC and could be potential biomarkers for diagnosing the disease.

Temporally and spatially controllable gene expression and knockout in mouse urothelium.

PubMed

Zhou, Haiping; Liu, Yan; He, Feng; Mo, Lan; Sun, Tung-Tien; Wu, Xue-Ru

2010-08-01

Urothelium that lines almost the entire urinary tract performs important functions and is prone to assaults by urinary microbials, metabolites, and carcinogens. To improve our understanding of urothelial physiology and disease pathogenesis, we sought to develop two novel transgenic systems, one that would allow inducible and urothelium-specific gene expression, and another that would allow inducible and urothelium-specific knockout. Toward this end, we combined the ability of the mouse uroplakin II promoter (mUPII) to drive urothelium-specific gene expression with a versatile tetracycline-mediated inducible system. We found that, when constructed under the control of mUPII, only a modified, reverse tetracycline trans-activator (rtTA-M2), but not its original version (rtTA), could efficiently trans-activate reporter gene expression in mouse urothelium on doxycycline (Dox) induction. The mUPII/rtTA-M2-inducible system retained its strict urothelial specificity, had no background activity in the absence of Dox, and responded rapidly to Dox administration. Using a reporter gene whose expression was secondarily controlled by histone remodeling, we were able to identify, colocalize with 5-bromo-2-deoxyuridine incorporation, and semiquantify newly divided urothelial cells. Finally, we established that, when combined with a Cre recombinase under the control of the tetracycline operon, the mUPII-driven rtTA-M2 could inducibly inactivate any gene of interest in mouse urothelium. The establishment of these two new transgenic mouse systems enables the manipulation of gene expression and/or inactivation in adult mouse urothelium at any given time, thus minimizing potential compensatory effects due to gene overexpression or loss and allowing more accurate modeling of urothelial diseases than previously reported constitutive systems.

Developmental Regulation of Diacylglycerol Acyltransferase Family Gene Expression in Tung Tree Tissues

PubMed Central

Cao, Heping; Shockey, Jay M.; Klasson, K. Thomas; Chapital, Dorselyn C.; Mason, Catherine B.; Scheffler, Brian E.

2013-01-01

Diacylglycerol acyltransferases (DGAT) catalyze the final and rate-limiting step of triacylglycerol (TAG) biosynthesis in eukaryotic organisms. DGAT genes have been identified in numerous organisms. Multiple isoforms of DGAT are present in eukaryotes. We previously cloned DGAT1 and DGAT2 genes of tung tree (Vernicia fordii), whose novel seed TAGs are useful in a wide range of industrial applications. The objective of this study was to understand the developmental regulation of DGAT family gene expression in tung tree. To this end, we first cloned a tung tree gene encoding DGAT3, a putatively soluble form of DGAT that possesses 11 completely conserved amino acid residues shared among 27 DGAT3s from 19 plant species. Unlike DGAT1 and DGAT2 subfamilies, DGAT3 is absent from animals. We then used TaqMan and SYBR Green quantitative real-time PCR, along with northern and western blotting, to study the expression patterns of the three DGAT genes in tung tree tissues. Expression results demonstrate that 1) all three isoforms of DGAT genes are expressed in developing seeds, leaves and flowers; 2) DGAT2 is the major DGAT mRNA in tung seeds, whose expression profile is well-coordinated with the oil profile in developing tung seeds; and 3) DGAT3 is the major form of DGAT mRNA in tung leaves, flowers and immature seeds prior to active tung oil biosynthesis. These results suggest that DGAT2 is probably the major TAG biosynthetic isoform in tung seeds and that DGAT3 gene likely plays a significant role in TAG metabolism in other tissues. Therefore, DGAT2 should be a primary target for tung oil engineering in transgenic organisms. PMID:24146944

Transcriptome-wide effects of inverted SINEs on gene expression and their impact on RNA polymerase II activity.

PubMed

Tajaddod, Mansoureh; Tanzer, Andrea; Licht, Konstantin; Wolfinger, Michael T; Badelt, Stefan; Huber, Florian; Pusch, Oliver; Schopoff, Sandy; Janisiw, Michael; Hofacker, Ivo; Jantsch, Michael F

2016-10-25

Short interspersed elements (SINEs) represent the most abundant group of non-long-terminal repeat transposable elements in mammalian genomes. In primates, Alu elements are the most prominent and homogenous representatives of SINEs. Due to their frequent insertion within or close to coding regions, SINEs have been suggested to play a crucial role during genome evolution. Moreover, Alu elements within mRNAs have also been reported to control gene expression at different levels. Here, we undertake a genome-wide analysis of insertion patterns of human Alus within transcribed portions of the genome. Multiple, nearby insertions of SINEs within one transcript are more abundant in tandem orientation than in inverted orientation. Indeed, analysis of transcriptome-wide expression levels of 15 ENCODE cell lines suggests a cis-repressive effect of inverted Alu elements on gene expression. Using reporter assays, we show that the negative effect of inverted SINEs on gene expression is independent of known sensors of double-stranded RNAs. Instead, transcriptional elongation seems impaired, leading to reduced mRNA levels. Our study suggests that there is a bias against multiple SINE insertions that can promote intramolecular base pairing within a transcript. Moreover, at a genome-wide level, mRNAs harboring inverted SINEs are less expressed than mRNAs harboring single or tandemly arranged SINEs. Finally, we demonstrate a novel mechanism by which inverted SINEs can impact on gene expression by interfering with RNA polymerase II.

Endo-β-mannanase and β-tubulin gene expression during the final phases of coffee seed maturation.

PubMed

Santos, F C; Clemente, A C S; Caixeta, F; Rosa, S D V F

2015-10-02

Coffee seeds begin to develop shortly after fertilization and can take 6 to 8 months to complete their formation, a period during which all the characteristics of the mature seed are determined, directly influencing physiological quality. However, little is known about the molecular mechanisms that act during coffee seed maturation. The objective of the current study was to analyze expression of the β-tubulin (TUB) and endo-β-mannanase (MAN) genes during different phases at the end of development and in different tissues of Coffea arabica seeds. The transcription levels of the TUB and MAN genes were quantified in a relative manner using qRT-PCR in whole seeds, and dissected into embryos and endosperms at different developmental stages. Greater expression of MAN was observed in whole seeds and in endosperms during the green stage, and in the embryo during the over-ripe stage. High TUB gene expression was observed in whole seeds during the green stage and, in the embryos, there were peaks in expression during the over-ripe stage. In endosperms, the peak of expression occurred in both the green stage and in the cherry stage. These results suggest participation of endo-β-mannanase during the initial seed developmental stages, and in the stages of physiological maturity in the embryo tissues. TUB gene expression varied depending on the developmental stage and section of seed analyzed, indicating the participation of β-tubulin during organogenesis and coffee seed maturation.

Adaptive Strategies and Pathogenesis of Clostridium difficile from In Vivo Transcriptomics

PubMed Central

Janoir, Claire; Denève, Cécile; Bouttier, Sylvie; Barbut, Frédéric; Hoys, Sandra; Caleechum, Laxmee; Chapetón-Montes, Diana; Pereira, Fátima C.; Henriques, Adriano O.; Collignon, Anne; Monot, Marc

2013-01-01

Clostridium difficile is currently the major cause of nosocomial intestinal diseases associated with antibiotic therapy in adults. In order to improve our knowledge of C. difficile-host interactions, we analyzed the genome-wide temporal expression of C. difficile 630 genes during the first 38 h of mouse colonization to identify genes whose expression is modulated in vivo, suggesting that they may play a role in facilitating the colonization process. In the ceca of the C. difficile-monoassociated mice, 549 genes of the C. difficile genome were differentially expressed compared to their expression during in vitro growth, and they were distributed in several functional categories. Overall, our results emphasize the roles of genes involved in host adaptation. Colonization results in a metabolic shift, with genes responsible for the fermentation as well as several other metabolic pathways being regulated inversely to those involved in carbon metabolism. In addition, several genes involved in stress responses, such as ferrous iron uptake or the response to oxidative stress, were regulated in vivo. Interestingly, many genes encoding conserved hypothetical proteins (CHP) were highly and specifically upregulated in vivo. Moreover, genes for all stages of sporulation were quickly induced in vivo, highlighting the observation that sporulation is central to the persistence of C. difficile in the gut and to its ability to spread in the environment. Finally, we inactivated two genes that were differentially expressed in vivo and evaluated the relative colonization fitness of the wild-type and mutant strains in coinfection experiments. We identified a CHP as a putative colonization factor, supporting the suggestion that the in vivo transcriptomic approach can unravel new C. difficile virulence genes. PMID:23897605

The mazEF toxin-antitoxin system as an attractive target in clinical isolates of Enterococcus faecium and Enterococcus faecalis.

PubMed

Soheili, Sara; Ghafourian, Sobhan; Sekawi, Zamberi; Neela, Vasantha Kumari; Sadeghifard, Nourkhoda; Taherikalani, Morovat; Khosravi, Afra; Ramli, Ramliza; Hamat, Rukman Awang

2015-01-01

The toxin-antitoxin (TA) system is a regulatory system where two sets of genes encode the toxin and its corresponding antitoxin. In this study, the prevalence of TA systems in independently isolated clinical isolates of Enterococcus faecium and Enterococcus faecalis was determined, the dominant TA system was identified, different virulence genes in E. faecium and E. faecalis were surveyed, the level of expression of the virulence and TA genes in normal and stress conditions was determined, and finally their associations with the TA genes were defined. Remarkably, the analysis demonstrated higBA and mazEF in all clinical isolates, and their locations were on chromosomes and plasmids, respectively. On the other hand, a quantitative analysis of TA and virulence genes revealed that the expression level in both genes is different under normal and stress conditions. The results obtained by anti-mazF peptide nucleic acids demonstrated that the expression level of virulence genes had decreased. These findings demonstrate an association between TA systems and virulence factors. The mazEF on the plasmids and the higBA TA genes on the chromosomes of all E. faecium and E. faecalis strains were dominant. Additionally, there was a decrease in the expression of virulence genes in the presence of anti-mazF peptide nucleic acids. Therefore, it is suggested that mazEF TA systems are potent and sensitive targets in all E. faecium and E. faecalis strains.

The mazEF toxin–antitoxin system as an attractive target in clinical isolates of Enterococcus faecium and Enterococcus faecalis

PubMed Central

Soheili, Sara; Ghafourian, Sobhan; Sekawi, Zamberi; Neela, Vasantha Kumari; Sadeghifard, Nourkhoda; Taherikalani, Morovat; Khosravi, Afra; Ramli, Ramliza; Hamat, Rukman Awang

2015-01-01

The toxin–antitoxin (TA) system is a regulatory system where two sets of genes encode the toxin and its corresponding antitoxin. In this study, the prevalence of TA systems in independently isolated clinical isolates of Enterococcus faecium and Enterococcus faecalis was determined, the dominant TA system was identified, different virulence genes in E. faecium and E. faecalis were surveyed, the level of expression of the virulence and TA genes in normal and stress conditions was determined, and finally their associations with the TA genes were defined. Remarkably, the analysis demonstrated higBA and mazEF in all clinical isolates, and their locations were on chromosomes and plasmids, respectively. On the other hand, a quantitative analysis of TA and virulence genes revealed that the expression level in both genes is different under normal and stress conditions. The results obtained by anti-mazF peptide nucleic acids demonstrated that the expression level of virulence genes had decreased. These findings demonstrate an association between TA systems and virulence factors. The mazEF on the plasmids and the higBA TA genes on the chromosomes of all E. faecium and E. faecalis strains were dominant. Additionally, there was a decrease in the expression of virulence genes in the presence of anti-mazF peptide nucleic acids. Therefore, it is suggested that mazEF TA systems are potent and sensitive targets in all E. faecium and E. faecalis strains. PMID:26005332

A regulation probability model-based meta-analysis of multiple transcriptomics data sets for cancer biomarker identification.

PubMed

Xie, Xin-Ping; Xie, Yu-Feng; Wang, Hong-Qiang

2017-08-23

Large-scale accumulation of omics data poses a pressing challenge of integrative analysis of multiple data sets in bioinformatics. An open question of such integrative analysis is how to pinpoint consistent but subtle gene activity patterns across studies. Study heterogeneity needs to be addressed carefully for this goal. This paper proposes a regulation probability model-based meta-analysis, jGRP, for identifying differentially expressed genes (DEGs). The method integrates multiple transcriptomics data sets in a gene regulatory space instead of in a gene expression space, which makes it easy to capture and manage data heterogeneity across studies from different laboratories or platforms. Specifically, we transform gene expression profiles into a united gene regulation profile across studies by mathematically defining two gene regulation events between two conditions and estimating their occurring probabilities in a sample. Finally, a novel differential expression statistic is established based on the gene regulation profiles, realizing accurate and flexible identification of DEGs in gene regulation space. We evaluated the proposed method on simulation data and real-world cancer datasets and showed the effectiveness and efficiency of jGRP in identifying DEGs identification in the context of meta-analysis. Data heterogeneity largely influences the performance of meta-analysis of DEGs identification. Existing different meta-analysis methods were revealed to exhibit very different degrees of sensitivity to study heterogeneity. The proposed method, jGRP, can be a standalone tool due to its united framework and controllable way to deal with study heterogeneity.

Genomic Features That Predict Allelic Imbalance in Humans Suggest Patterns of Constraint on Gene Expression Variation

PubMed Central

Fédrigo, Olivier; Haygood, Ralph; Mukherjee, Sayan; Wray, Gregory A.

2009-01-01

Variation in gene expression is an important contributor to phenotypic diversity within and between species. Although this variation often has a genetic component, identification of the genetic variants driving this relationship remains challenging. In particular, measurements of gene expression usually do not reveal whether the genetic basis for any observed variation lies in cis or in trans to the gene, a distinction that has direct relevance to the physical location of the underlying genetic variant, and which may also impact its evolutionary trajectory. Allelic imbalance measurements identify cis-acting genetic effects by assaying the relative contribution of the two alleles of a cis-regulatory region to gene expression within individuals. Identification of patterns that predict commonly imbalanced genes could therefore serve as a useful tool and also shed light on the evolution of cis-regulatory variation itself. Here, we show that sequence motifs, polymorphism levels, and divergence levels around a gene can be used to predict commonly imbalanced genes in a human data set. Reduction of this feature set to four factors revealed that only one factor significantly differentiated between commonly imbalanced and nonimbalanced genes. We demonstrate that these results are consistent between the original data set and a second published data set in humans obtained using different technical and statistical methods. Finally, we show that variation in the single allelic imbalance-associated factor is partially explained by the density of genes in the region of a target gene (allelic imbalance is less probable for genes in gene-dense regions), and, to a lesser extent, the evenness of expression of the gene across tissues and the magnitude of negative selection on putative regulatory regions of the gene. These results suggest that the genomic distribution of functional cis-regulatory variants in the human genome is nonrandom, perhaps due to local differences in evolutionary constraint. PMID:19506001

Imaging Oncogene Expression

PubMed Central

Mukherjee, Archana; Wickstrom, Eric

2009-01-01

This review briefly outlines the importance of molecular imaging, particularly imaging of endogenous gene expression for noninvasive genetic analysis of radiographic masses. The concept of antisense imaging agents and the advantages and challenges in the development of hybridization probes for in vivo imaging are described. An overview of the investigations on oncogene expression imaging is given. Finally, the need for further improvement in antisense-based imaging agents and directions to improve oncogene mRNA targeting is stated. PMID:19264436

Purinergic receptor ligands stimulate pro-opiomelanocortin gene expression in AtT-20 pituitary corticotroph cells.

PubMed

Zhao, L-F; Iwasaki, Y; Oki, Y; Tsugita, M; Taguchi, T; Nishiyama, M; Takao, T; Kambayashi, M; Hashimoto, K

2006-04-01

Although recent studies have suggested that purinergic receptors are expressed in the anterior pituitary gland, their involvement in the regulation of pituitary hormone gene expression is not completely understood. In the present study, we examined the expression of purinergic receptors and the effects of purinergic receptor ligands on pro-opiomelanocortin (POMC) gene expression, in AtT20 mouse corticotroph cells. We identified the expression of most of the purinergic receptor subtypes (A1, A2, P2X1, 3-7, P2Y1, 2, 4) mRNAs, analysed by the reverse transcriptase-polymerase chain reaction. We also found that adenosine and ATP, two representative and endogenous agonists of A1-3 and P2X/P2Y receptors, respectively, stimulated the 5'-promoter activity of the POMC gene in a dose- and time-related manner. When these ligands were simultaneously used with corticotrophin-releasing hormone (CRH), effects that were more than additive were observed, suggesting an enhancing role of these compounds in CRH-mediated adrenocorticotrophic hormone (ACTH) synthesis. These ligands also stimulated the expression of transcription factors involved in the regulation of the POMC gene, but did not enhance ACTH secretion. Finally, the positive effect of adenosine as well as CRH was completely inhibited by the protein kinase A inhibitor H89, whereas that of ATP was not influenced, indicating that different intracellular signalling pathways mediate these effects. Altogether, our results suggest a stimulatory role for these purinergic receptor ligands in the regulation of POMC gene expression in corticotroph cells. Because adenosine and ATP are known to be produced within the pituitary gland, it is possible they may be acting in an autocrine/paracrine fashion.

CRISP-3, a protein with homology to plant defense proteins, is expressed in mouse B cells under the control of Oct2.

PubMed

Pfisterer, P; König, H; Hess, J; Lipowsky, G; Haendler, B; Schleuning, W D; Wirth, T

1996-11-01

The Oct2 transcription factor is expressed throughout the B-lymphoid lineage and plays an essential role during the terminal phase of B-cell differentiation. Several genes specifically expressed in B lymphocytes have been identified that contain a functional octamer motif in their regulatory elements. However, expression of only a single gene, the murine CD36 gene, has been shown to date to be dependent on Oct2. Here, we present the identification and characterization of a further gene, coding for cysteine-rich secreted protein 3 (CRISP-3), whose expression in B cells is regulated by Oct2. We show that CRISP-3 is expressed in the B-lymphoid lineage specifically at the pre-B-cell stage. By using different experimental strategies, including nuclear run-on experiments, we demonstrate that this gene is transcriptionally activated by Oct2. Furthermore, analysis of CRISP-3 expression in primary B cells derived from either wild-type or Oct2-deficient mice demonstrates the dependence on Oct2. Two variant octamer motifs were identified in the upstream promoter region of the crisp-3 gene, and Oct2 interacts with both of them in vitro. Cotransfection experiments with expression vectors for Oct1 and Oct2 together with a reporter driven by the crisp-3 promoter showed that transcriptional activation of this promoter can only be achieved with Oct2. The C-terminal transactivation domain of Oct2 is required for this activation. Finally, introducing specific mutations in the two variant octamer motifs revealed that both of them are important for full transcriptional activation by Oct2.

Role of Ox-PAPCs in the Differentiation of Mesenchymal Stem Cells (MSCs) and Runx2 and PPARγ2 Expression in MSCs-Like of Osteoporotic Patients

PubMed Central

Valenti, Maria Teresa; Garbin, Ulisse; Pasini, Andrea; Zanatta, Mirko; Stranieri, Chiara; Manfro, Stefania; Zucal, Chiara; Dalle Carbonare, Luca

2011-01-01

Background Mesenchymal stem cells (MSCs) can differentiate into osteoblasts and adipocytes and conditions causing bone loss may induce a switch from the osteoblast to adipocyte lineage. In addition, the expression of Runx2 and the PPARγ2 transcription factor genes is essential for cellular commitment to an osteogenic and adipogenic differentiation, respectively. Modified lipoproteins derived from the oxidation of arachidonate-containing phospholipids (ox-PAPCs: POVPC, PGPC and PEIPC) are considered important factors in atherogenesis. Methodology We investigated the effect of ox-PAPCs on osteogenesis and adipogenesis in human mesenchymal stem cells (hMSCs). In particular, we analyzed the transcription factor Runx2 and the PPARγ2 gene expression during osteogenic and adipogenic differentiation in absence and in presence of ox-PAPCs. We also analyzed gene expression level in a panel of osteoblastic and adipogenic differentiation markers. In addition, as circulating blood cells can be used as a “sentinel” that responds to changes in the macro- or micro-environment, we analyzed the Runx2 and the PPARγ2 gene expression in MSCs-like and ox-PAPC levels in serum of osteoporotic patients (OPs). Finally, we examined the effects of sera obtained from OPs in hMSCs comparing the results with age-matched normal donors (NDs). Principal findings Quantitative RT-PCR demonstrated that ox-PAPCs enhanced PPARγ2 and adipogenic gene expression and reduced Runx2 and osteoblast differentiation marker gene expression in differentiating hMSCs. In OPs, ox-PAPC levels and PPARγ2 expression were higher than in NDs, whereas Runx2 was lower than in ND circulant MSCs-like. Conclusions Ox-PAPCs affect the osteogenic differentiation by promoting adipogenic differentiation and this effect may appear involved in bone loss in OPs. PMID:21674037

Differential co-expression analysis of rheumatoid arthritis with microarray data.

PubMed

Wang, Kunpeng; Zhao, Liqiang; Liu, Xuefeng; Hao, Zhenyong; Zhou, Yong; Yang, Chuandong; Li, Hongqiang

2014-11-01

The aim of the present study was to investigate the underlying molecular mechanisms of rheumatoid arthritis (RA) using microarray expression profiles from osteoarthritis and RA patients, to improve diagnosis and treatment strategies for the condition. The gene expression profile of GSE27390 was downloaded from Gene Expression Omnibus, including 19 samples from patients with RA (n=9) or osteoarthritis (n=10). Firstly, the differentially expressed genes (DEGs) were obtained with the thresholds of |logFC|>1.0 and P<0.05, using the t‑test method in LIMMA package. Then, differentially co-expressed genes (DCGs) and differentially co-expressed links (DCLs) were screened with q<0.25 by the differential coexpression analysis and differential regulation analysis of gene expression microarray data package. Secondly, pathway enrichment analysis for DCGs was performed by the Database for Annotation, Visualization and Integrated Discovery and the DCLs associated with RA were selected by comparing the obtained DCLs with known transcription factor (TF)-targets in the TRANSFAC database. Finally, the obtained TFs were mapped to the known TF-targets to construct the network using cytoscape software. A total of 1755 DEGs, 457 DCGs and 101988 DCLs were achieved and there were 20 TFs in the obtained six TF-target relations (STAT3-TNF, PBX1‑PLAU, SOCS3-STAT3, GATA1-ETS2, ETS1-ICAM4 and CEBPE‑GATA1) and 457 DCGs. A number of TF-target relations in the constructed network were not within DCLs when the TF and target gene were DCGs. The identified TFs may have an important role in the pathogenesis of RA and have the potential to be used as biomarkers for the development of novel diagnostic and therapeutic strategies for RA.

The embryonic genes Dkk3, Hoxd8, Hoxd9 and Tbx1 identify muscle types in a diet-independent and fiber-type unrelated way.

PubMed

de Wilde, Janneke; Hulshof, Martijn F M; Boekschoten, Mark V; de Groot, Philip; Smit, Egbert; Mariman, Edwin C M

2010-03-15

The mouse skeletal muscle is composed of four distinct fiber types that differ in contractile function, number of mitochondria and metabolism. Every muscle type has a specific composition and distribution of the four fiber types. To find novel genes involved in specifying muscle types, we used microarray analysis to compare the gastrocnemius with the quadriceps from mice fed a low fat diet (LFD) or high fat diet (HFD) for 8 weeks. Additional qPCR analysis were performed in the gastrocnemius, quadriceps and soleus muscle from mice fed an LFD or HFD for 20 weeks. In mice fed the 8-week LFD 162 genes were differentially expressed in the gastrocnemius vs. the quadriceps. Genes with the strongest differences in expression were markers for oxidative fiber types (e.g. Tnni1) and genes which are known to be involved in embryogenesis (Dkk3, Hoxd8,Hoxd9 and Tbx1). Also Dkk2, Hoxa5, Hoxa10, Hoxc9, Hoxc10, Hoxc6 and Tbx15 were detectably, but not differentially expressed in adult muscle tissue. Expression of differentially expressed genes was not influenced by an 8-week or 20-week HFD. Comparing gastrocnemius, quadriceps and soleus, expression of Hoxd8 and Hoxd9 was not related with expression of markers for the four different fiber types. We found that the expression of both Hoxd8 and Hoxd9 was much higher in the gastrocnemius than in the quadriceps or soleus, whereas the expression of Dkk3 was high in quadriceps, but low in both gastrocnemius and soleus. Finally, expression of Tbx1 was high in quadriceps, intermediate in soleus and low in gastrocnemius. We found that genes from the Dkk family, Hox family and Tbx family are detectably expressed in adult mouse muscle. Interestingly, expression of Dkk3, Hoxd8, Hoxd9 and Tbx1 was highly different between gastrocnemius, quadriceps and soleus. In fact, every muscle type showed a unique combination of expression of these four genes which was not influenced by diet. Altogether, we conclude that genes important for embryogenesis identify mouse muscle types in a diet-independent and fiber type-unrelated manner.

Eotaxin-3 and a uniquely conserved gene-expression profile in eosinophilic esophagitis

PubMed Central

Blanchard, Carine; Wang, Ning; Stringer, Keith F.; Mishra, Anil; Fulkerson, Patricia C.; Abonia, J. Pablo; Jameson, Sean C.; Kirby, Cassie; Konikoff, Michael R.; Collins, Margaret H.; Cohen, Mitchell B.; Akers, Rachel; Hogan, Simon P.; Assa’ad, Amal H.; Putnam, Philip E.; Aronow, Bruce J.; Rothenberg, Marc E.

2006-01-01

Eosinophilic esophagitis (EE) is an emerging disorder with a poorly understood pathogenesis. In order to define disease mechanisms, we took an empirical approach analyzing esophageal tissue by a genome-wide microarray expression analysis. EE patients had a striking transcript signature involving 1% of the human genome that was remarkably conserved across sex, age, and allergic status and was distinct from that associated with non-EE chronic esophagitis. Notably, the gene encoding the eosinophil-specific chemoattractant eotaxin-3 (also known as CCL26) was the most highly induced gene in EE patients compared with its expression level in healthy individuals. Esophageal eotaxin-3 mRNA and protein levels strongly correlated with tissue eosinophilia and mastocytosis. Furthermore, a single-nucleotide polymorphism in the human eotaxin-3 gene was associated with disease susceptibility. Finally, mice deficient in the eotaxin receptor (also known as CCR3) were protected from experimental EE. These results implicate eotaxin-3 as a critical effector molecule for EE and provide insight into disease pathogenesis. PMID:16453027

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gompers, Andrea L.; Su-Feher, Linda; Ellegood, Jacob

The chromatin remodeling gene CHD8 represents a central node in neurodevelopmental gene networks implicated in autism. In this paper, we examined the impact of germline heterozygous frameshift Chd8 mutation on neurodevelopment in mice. Chd8 +/ del5 mice displayed normal social interactions with no repetitive behaviors but exhibited cognitive impairment correlated with increased regional brain volume, validating that phenotypes of Chd8 +/ del5 mice overlap pathology reported in humans with CHD8 mutations. We applied network analysis to characterize neurodevelopmental gene expression, revealing widespread transcriptional changes in Chd8 +/ del5 mice across pathways disrupted in neurodevelopmental disorders, including neurogenesis, synaptic processes andmore » neuroimmune signaling. We identified a co-expression module with peak expression in early brain development featuring dysregulation of RNA processing, chromatin remodeling and cell-cycle genes enriched for promoter binding by Chd8, and we validated increased neuronal proliferation and developmental splicing perturbation in Chd8 +/ del5 mice. Finally, this integrative analysis offers an initial picture of the consequences of Chd8 haploinsufficiency for brain development.« less

Impulsive Choice in Mice Lacking Paternal Expression of Grb10 Suggests Intragenomic Conflict in Behavior

PubMed Central

Dent, Claire L.; Humby, Trevor; Lewis, Katie; Ward, Andrew; Fischer-Colbrie, Reiner; Wilkinson, Lawrence S.; Wilkins, Jon F.; Isles, Anthony R.

2018-01-01

Imprinted genes are expressed from one parental allele only as a consequence of epigenetic events that take place in the mammalian germ line and are thought to have evolved through intragenomic conflict between parental alleles. We demonstrate, for the first time, oppositional effects of imprinted genes on brain and behavior. Specifically, we show that mice lacking paternal Grb10 make fewer impulsive choices, with no dissociable effects on a separate measure of impulsive action. Taken together with previous work showing that mice lacking maternal Nesp55 make more impulsive choices, this suggests that impulsive choice behavior is a substrate for the action of genomic imprinting. Moreover, the contrasting effect of these two genes suggests that impulsive choices are subject to intragenomic conflict and that maternal and paternal interests pull this behavior in opposite directions. Finally, these data may also indicate that an imbalance in expression of imprinted genes contributes to pathological conditions such as gambling and drug addiction, where impulsive behavior becomes maladaptive. PMID:29563147

Comparative analysis of laparoscopic and ultrasound-guided biopsy methods for gene expression analysis in transgenic goats.

PubMed

Melo, C H; Sousa, F C; Batista, R I P T; Sanchez, D J D; Souza-Fabjan, J M G; Freitas, V J F; Melo, L M; Teixeira, D I A

2015-07-31

The present study aimed to compare laparoscopic (LP) and ultrasound-guided (US) biopsy methods to obtain either liver or splenic tissue samples for ectopic gene expression analysis in transgenic goats. Tissue samples were collected from human granulocyte colony stimulating factor (hG-CSF)-transgenic bucks and submitted to real-time PCR for the endogenous genes (Sp1, Baff, and Gapdh) and the transgene (hG-CSF). Both LP and US biopsy methods were successful in obtaining liver and splenic samples that could be analyzed by PCR (i.e., sufficient sample sizes and RNA yield were obtained). Although the number of attempts made to obtain the tissue samples was similar (P > 0.05), LP procedures took considerably longer than the US method (P = 0.03). Finally, transgene transcripts were not detected in spleen or liver samples. Thus, for the phenotypic characterization of a transgenic goat line, investigation of ectopic gene expression can be made successfully by LP or US biopsy, avoiding the traditional approach of euthanasia.

Expression of putative sex-determining genes during the thermosensitive period of gonad development in the snapping turtle, Chelydra serpentina.

PubMed

Rhen, T; Metzger, K; Schroeder, A; Woodward, R

2007-01-01

Modes of sex determination are quite variable in vertebrates. The developmental decision to form a testis or an ovary can be influenced by one gene, several genes, environmental variables, or a combination of these factors. Nevertheless, certain morphogenetic aspects of sex determination appear to be conserved in amniotes. Here we clone fragments of nine candidate sex-determining genes from the snapping turtle Chelydra serpentina, a species with temperature-dependent sex determination (TSD). We then analyze expression of these genes during the thermosensitive period of gonad development. In particular, we compare gene expression profiles in gonads from embryos incubated at a male-producing temperature to those from embryos at a female-producing temperature. Expression of Dmrt1 and Sox9 mRNA increased gradually at the male-producing temperature, but was suppressed at the female-producing temperature. This finding suggests that Dmrt1 and Sox9 play a role in testis development. In contrast, expression of aromatase, androgen receptor (Ar), and Foxl2 mRNA was constant at the male-producing temperature, but increased several-fold in embryos at the female-producing temperature. Aromatase, Ar, and Foxl2 may therefore play a role in ovary development. In addition, there was a small temperature effect on ER alpha expression with lower mRNA levels found in embryos at the female-producing temperature. Finally, Dax1, Fgf9, and SF-1 were not differentially expressed during the sex-determining period, suggesting these genes are not involved in sex determination in the snapping turtle. Comparison of gene expression profiles among amniotes indicates that Dmrt1 and Sox9 are part of a core testis-determining pathway and that Ar, aromatase, ER alpha, and Foxl2 are part of a core ovary-determining pathway. 2007 S. Karger AG, Basel

Predicting hepatocellular carcinoma through cross-talk genes identified by risk pathways

PubMed Central

Shao, Zhuo; Huo, Diwei; Zhang, Denan; Xie, Hongbo; Yang, Jingbo; Liu, Qiuqi; Chen, Xiujie

2018-01-01

Hepatocellular carcinoma (HCC) is the most frequent type of liver cancer with poor survival rate and high mortality. Despite efforts on the mechanism of HCC, new molecular markers are needed for exact diagnosis, evaluation and treatment. Here, we combined transcriptome of HCC with networks and pathways to identify reliable molecular markers. Through integrating 249 differentially expressed genes with syncretic protein interaction networks, we constructed a HCC-specific network, from which we further extracted 480 pivotal genes. Based on the cross-talk between the enriched pathways of the pivotal genes, we finally identified a HCC signature of 45 genes, which could accurately distinguish HCC patients with normal individuals and reveal the prognosis of HCC patients. Among these 45 genes, 15 showed dysregulated expression patterns and a part have been reported to be associated with HCC and/or other cancers. These findings suggested that our identified 45 gene signature could be potential and valuable molecular markers for diagnosis and evaluation of HCC. PMID:29765536

Widespread antisense transcription of Populus genome under drought.

PubMed

Yuan, Yinan; Chen, Su

2018-06-06

Antisense transcription is widespread in many genomes and plays important regulatory roles in gene expression. The objective of our study was to investigate the extent and functional relevance of antisense transcription in forest trees. We employed Populus, a model tree species, to probe the antisense transcriptional response of tree genome under drought, through stranded RNA-seq analysis. We detected nearly 48% of annotated Populus gene loci with antisense transcripts and 44% of them with co-transcription from both DNA strands. Global distribution of reads pattern across annotated gene regions uncovered that antisense transcription was enriched in untranslated regions while sense reads were predominantly mapped in coding exons. We further detected 1185 drought-responsive sense and antisense gene loci and identified a strong positive correlation between the expression of antisense and sense transcripts. Additionally, we assessed the antisense expression in introns and found a strong correlation between intronic expression and exonic expression, confirming antisense transcription of introns contributes to transcriptional activity of Populus genome under drought. Finally, we functionally characterized drought-responsive sense-antisense transcript pairs through gene ontology analysis and discovered that functional groups including transcription factors and histones were concordantly regulated at both sense and antisense transcriptional level. Overall, our study demonstrated the extensive occurrence of antisense transcripts of Populus genes under drought and provided insights into genome structure, regulation pattern and functional significance of drought-responsive antisense genes in forest trees. Datasets generated in this study serve as a foundation for future genetic analysis to improve our understanding of gene regulation by antisense transcription.

Effect of Periodontal Pathogens on the Metatranscriptome of a Healthy Multispecies Biofilm Model

PubMed Central

Duran-Pinedo, Ana

2012-01-01

Oral bacterial biofilms are highly complex microbial communities with up to 700 different bacterial taxa. We report here the use of metatranscriptomic analysis to study patterns of community gene expression in a multispecies biofilm model composed of species found in healthy oral biofilms (Actinomyces naeslundii, Lactobacillus casei, Streptococcus mitis, Veillonella parvula, and Fusobacterium nucleatum) and the same biofilm plus the periodontopathogens Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. The presence of the periodontopathogens altered patterns in gene expression, and data indicate that transcription of protein-encoding genes and small noncoding RNAs is stimulated. In the healthy biofilm hypothetical proteins, transporters and transcriptional regulators were upregulated while chaperones and cell division proteins were downregulated. However, when the pathogens were present, chaperones were highly upregulated, probably due to increased levels of stress. We also observed a significant upregulation of ABC transport systems and putative transposases. Changes in Clusters of Orthologous Groups functional categories as well as gene set enrichment analysis based on Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways showed that in the absence of pathogens, only sets of proteins related to transport and secondary metabolism were upregulated, while in the presence of pathogens, proteins related to growth and division as well as a large portion of transcription factors were upregulated. Finally, we identified several small noncoding RNAs whose predicted targets were genes differentially expressed in the open reading frame libraries. These results show the importance of pathogens controlling gene expression of a healthy oral community and the usefulness of metatranscriptomic techniques to study gene expression profiles in complex microbial community models. PMID:22328675

A Small System—High-Resolution Study of Metabolic Adaptation in the Central Metabolic Pathway to Temperate Climates in Drosophila melanogaster

PubMed Central

Lavington, Erik; Cogni, Rodrigo; Kuczynski, Caitlin; Koury, Spencer; Behrman, Emily L.; O’Brien, Katherine R.; Schmidt, Paul S.; Eanes, Walter F.

2014-01-01

In this article, we couple the geographic variation in 127 single-nucleotide polymorphism (SNP) frequencies in genes of 46 enzymes of central metabolism with their associated cis-expression variation to predict latitudinal or climatic-driven gene expression changes in the metabolic architecture of Drosophila melanogaster. Forty-two percent of the SNPs in 65% of the genes show statistically significant clines in frequency with latitude across the 20 local population samples collected from southern Florida to Ontario. A number of SNPs in the screened genes are also associated with significant expression variation within the Raleigh population from North Carolina. A principal component analysis of the full variance–covariance matrix of latitudinal changes in SNP-associated standardized gene expression allows us to identify those major genes in the pathway and its associated branches that are likely targets of natural selection. When embedded in a central metabolic context, we show that these apparent targets are concentrated in the genes of the upper glycolytic pathway and pentose shunt, those controlling glycerol shuttle activity, and finally those enzymes associated with the utilization of glutamate and pyruvate. These metabolites possess high connectivity and thus may be the points where flux balance can be best shifted. We also propose that these points are conserved points associated with coupling energy homeostasis and energy sensing in mammals. We speculate that the modulation of gene expression at specific points in central metabolism that are associated with shifting flux balance or possibly energy-state sensing plays a role in adaptation to climatic variation. PMID:24770333

BioVLAB-mCpG-SNP-EXPRESS: A system for multi-level and multi-perspective analysis and exploration of DNA methylation, sequence variation (SNPs), and gene expression from multi-omics data.

PubMed

Chae, Heejoon; Lee, Sangseon; Seo, Seokjun; Jung, Daekyoung; Chang, Hyeonsook; Nephew, Kenneth P; Kim, Sun

2016-12-01

Measuring gene expression, DNA sequence variation, and DNA methylation status is routinely done using high throughput sequencing technologies. To analyze such multi-omics data and explore relationships, reliable bioinformatics systems are much needed. Existing systems are either for exploring curated data or for processing omics data in the form of a library such as R. Thus scientists have much difficulty in investigating relationships among gene expression, DNA sequence variation, and DNA methylation using multi-omics data. In this study, we report a system called BioVLAB-mCpG-SNP-EXPRESS for the integrated analysis of DNA methylation, sequence variation (SNPs), and gene expression for distinguishing cellular phenotypes at the pairwise and multiple phenotype levels. The system can be deployed on either the Amazon cloud or a publicly available high-performance computing node, and the data analysis and exploration of the analysis result can be conveniently done using a web-based interface. In order to alleviate analysis complexity, all the process are fully automated, and graphical workflow system is integrated to represent real-time analysis progression. The BioVLAB-mCpG-SNP-EXPRESS system works in three stages. First, it processes and analyzes multi-omics data as input in the form of the raw data, i.e., FastQ files. Second, various integrated analyses such as methylation vs. gene expression and mutation vs. methylation are performed. Finally, the analysis result can be explored in a number of ways through a web interface for the multi-level, multi-perspective exploration. Multi-level interpretation can be done by either gene, gene set, pathway or network level and multi-perspective exploration can be explored from either gene expression, DNA methylation, sequence variation, or their relationship perspective. The utility of the system is demonstrated by performing analysis of phenotypically distinct 30 breast cancer cell line data set. BioVLAB-mCpG-SNP-EXPRESS is available at http://biohealth.snu.ac.kr/software/biovlab_mcpg_snp_express/. Copyright © 2016 Elsevier Inc. All rights reserved.

Transcriptional Signatures of Sleep Duration Discordance in Monozygotic Twins.

PubMed

Watson, N F; Buchwald, D; Delrow, J J; Altemeier, W A; Vitiello, M V; Pack, A I; Bamshad, M; Noonan, C; Gharib, S A

2017-01-01

Habitual short sleep duration is associated with adverse metabolic, cardiovascular, and inflammatory effects. Co-twin study methodologies account for familial (eg, genetics and shared environmental) confounding, allowing assessment of subtle environmental effects, such as the effect of habitual short sleep duration on gene expression. Therefore, we investigated gene expression in monozygotic twins discordant for actigraphically phenotyped habitual sleep duration. Eleven healthy monozygotic twin pairs (82% female; mean age 42.7 years; SD = 18.1), selected based on subjective sleep duration discordance, were objectively phenotyped for habitual sleep duration with 2 weeks of wrist actigraphy. Peripheral blood leukocyte (PBL) RNA from fasting blood samples was obtained on the final day of actigraphic measurement and hybridized to Illumina humanHT-12 microarrays. Differential gene expression was determined between paired samples and mapped to functional categories using Gene Ontology. Finally, a more comprehensive gene set enrichment analysis was performed based on the entire PBL transcriptome. The mean 24-hour sleep duration of the total sample was 439.2 minutes (SD = 46.8 minutes; range 325.4-521.6 minutes). Mean within-pair sleep duration difference per 24 hours was 64.4 minutes (SD = 21.2; range 45.9-114.6 minutes). The twin cohort displayed distinctive pathway enrichment based on sleep duration differences. Habitual short sleep was associated with up-regulation of genes involved in transcription, ribosome, translation, and oxidative phosphorylation. Unexpectedly, genes down-regulated in short sleep twins were highly enriched in immuno-inflammatory pathways such as interleukin signaling and leukocyte activation, as well as developmental programs, coagulation cascade, and cell adhesion. Objectively assessed habitual sleep duration in monozygotic twin pairs appears to be associated with distinct patterns of differential gene expression and pathway enrichment. By accounting for familial confounding and measuring real life sleep duration, our study shows the transcriptomic effects of habitual short sleep on dysregulated immune response and provides a potential link between sleep deprivation and adverse metabolic, cardiovascular, and inflammatory outcomes. © Sleep Research Society 2017. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.

Regulation of behaviorally associated gene networks in worker honey bee ovaries

PubMed Central

Wang, Ying; Kocher, Sarah D.; Linksvayer, Timothy A.; Grozinger, Christina M.; Page, Robert E.; Amdam, Gro V.

2012-01-01

SUMMARY Several lines of evidence support genetic links between ovary size and division of labor in worker honey bees. However, it is largely unknown how ovaries influence behavior. To address this question, we first performed transcriptional profiling on worker ovaries from two genotypes that differ in social behavior and ovary size. Then, we contrasted the differentially expressed ovarian genes with six sets of available brain transcriptomes. Finally, we probed behavior-related candidate gene networks in wild-type ovaries of different sizes. We found differential expression in 2151 ovarian transcripts in these artificially selected honey bee strains, corresponding to approximately 20.3% of the predicted gene set of honey bees. Differences in gene expression overlapped significantly with changes in the brain transcriptomes. Differentially expressed genes were associated with neural signal transmission (tyramine receptor, TYR) and ecdysteroid signaling; two independently tested nuclear hormone receptors (HR46 and ftz-f1) were also significantly correlated with ovary size in wild-type bees. We suggest that the correspondence between ovary and brain transcriptomes identified here indicates systemic regulatory networks among hormones (juvenile hormone and ecdysteroids), pheromones (queen mandibular pheromone), reproductive organs and nervous tissues in worker honey bees. Furthermore, robust correlations between ovary size and neuraland endocrine response genes are consistent with the hypothesized roles of the ovaries in honey bee behavioral regulation. PMID:22162860

The Ubiquitin-Conjugating Enzyme Gene Family in Longan (Dimocarpus longan Lour.): Genome-Wide Identification and Gene Expression during Flower Induction and Abiotic Stress Responses.

PubMed

Jue, Dengwei; Sang, Xuelian; Liu, Liqin; Shu, Bo; Wang, Yicheng; Xie, Jianghui; Liu, Chengming; Shi, Shengyou

2018-03-15

Ubiquitin-conjugating enzymes (E2s or UBC enzymes) play vital roles in plant development and combat various biotic and abiotic stresses. Longan ( Dimocarpus longan Lour.) is an important fruit tree in the subtropical region of Southeast Asia and Australia; however the characteristics of the UBC gene family in longan remain unknown. In this study, 40 D. longan UBC genes ( DlUBCs ), which were classified into 15 groups, were identified in the longan genome. An RNA-seq based analysis showed that DlUBCs showed distinct expression in nine longan tissues. Genome-wide RNA-seq and qRT-PCR based gene expression analysis revealed that 11 DlUBCs were up- or down-regualted in the cultivar "Sijimi" (SJ), suggesting that these genes may be important for flower induction. Finally, qRT-PCR analysis showed that the mRNA levels of 13 DlUBCs under SA (salicylic acid) treatment, seven under methyl jasmonate (MeJA) treatment, 27 under heat treatment, and 16 under cold treatment were up- or down-regulated, respectively. These results indicated that the DlUBCs may play important roles in responses to abiotic stresses. Taken together, our results provide a comprehensive insight into the organization, phylogeny, and expression patterns of the longan UBC genes, and therefore contribute to the greater understanding of their biological roles in longan.

Complexity and specificity of the maize (Zea mays L.) root hair transcriptome.

PubMed

Hey, Stefan; Baldauf, Jutta; Opitz, Nina; Lithio, Andrew; Pasha, Asher; Provart, Nicholas; Nettleton, Dan; Hochholdinger, Frank

2017-04-01

Root hairs are tubular extensions of epidermis cells. Transcriptome profiling demonstrated that the single cell-type root hair transcriptome was less complex than the transcriptome of multiple cell-type primary roots without root hairs. In total, 831 genes were exclusively and 5585 genes were preferentially expressed in root hairs [false discovery rate (FDR) ≤1%]. Among those, the most significantly enriched Gene Ontology (GO) functional terms were related to energy metabolism, highlighting the high energy demand for the development and function of root hairs. Subsequently, the maize homologs for 138 Arabidopsis genes known to be involved in root hair development were identified and their phylogenetic relationship and expression in root hairs were determined. This study indicated that the genetic regulation of root hair development in Arabidopsis and maize is controlled by common genes, but also shows differences which need to be dissected in future genetic experiments. Finally, a maize root view of the eFP browser was implemented including the root hair transcriptome of the present study and several previously published maize root transcriptome data sets. The eFP browser provides color-coded expression levels for these root types and tissues for any gene of interest, thus providing a novel resource to study gene expression and function in maize roots. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Analysis of regulatory mechanisms of an insulin-inducible SHARP-2 gene by (S)-Equol.

PubMed

Haneishi, Ayumi; Takagi, Katsuhiro; Asano, Kosuke; Yamamoto, Taichi; Tanaka, Takashi; Nakamura, Soichiro; Noguchi, Tamio; Yamada, Kazuya

2012-09-01

Small compounds that activate the insulin-dependent signaling pathway have potential therapeutic applications in controlling type 2 diabetes mellitus. The rat enhancer of split- and hairy-related protein-2 (SHARP-2) is an insulin-inducible transcription factor that decreases expression of the phosphoenolpyruvate carboxykinase gene, a gluconeogenic enzyme gene. In this study, we screened for soybean isoflavones that can induce the rat SHARP-2 gene expression and analyzed their mechanism(s). Genistein and (S)-Equol, a metabolite of daidzein, induced rat SHARP-2 gene expression in H4IIE rat hepatoma cells. The (S)-Equol induction was mediated by both the phosphoinositide 3-kinase- and protein kinase C (PKC)-pathways. When a dominant negative form of atypical PKC lambda (aPKCλ) was expressed, the induction of SHARP-2 mRNA level by (S)-Equol was inhibited. In addition, Western blot analyses showed that (S)-Equol rapidly activated both aPKCλ and classical PKC alpha. Furthermore, the (S)-Equol induction was inhibited by treatment with a RNA polymerase inhibitor or a protein synthesis inhibitor. Finally, a reporter gene assay revealed that the transcriptional stimulation by (S)-Equol was mediated by nucleotide sequences located between -4687 and -4133 of the rat SHARP-2 gene. Thus, we conclude that (S)-Equol is an useful dietary supplement to control type 2 diabetes mellitus. Copyright © 2012 Elsevier Inc. All rights reserved.

De novo Transcriptome Assembly of Common Wild Rice (Oryza rufipogon Griff.) and Discovery of Drought-Response Genes in Root Tissue Based on Transcriptomic Data.

PubMed

Tian, Xin-Jie; Long, Yan; Wang, Jiao; Zhang, Jing-Wen; Wang, Yan-Yan; Li, Wei-Min; Peng, Yu-Fa; Yuan, Qian-Hua; Pei, Xin-Wu

2015-01-01

The perennial O. rufipogon (common wild rice), which is considered to be the ancestor of Asian cultivated rice species, contains many useful genetic resources, including drought resistance genes. However, few studies have identified the drought resistance and tissue-specific genes in common wild rice. In this study, transcriptome sequencing libraries were constructed, including drought-treated roots (DR) and control leaves (CL) and roots (CR). Using Illumina sequencing technology, we generated 16.75 million bases of high-quality sequence data for common wild rice and conducted de novo assembly and annotation of genes without prior genome information. These reads were assembled into 119,332 unigenes with an average length of 715 bp. A total of 88,813 distinct sequences (74.42% of unigenes) significantly matched known genes in the NCBI NT database. Differentially expressed gene (DEG) analysis showed that 3617 genes were up-regulated and 4171 genes were down-regulated in the CR library compared with the CL library. Among the DEGs, 535 genes were expressed in roots but not in shoots. A similar comparison between the DR and CR libraries showed that 1393 genes were up-regulated and 315 genes were down-regulated in the DR library compared with the CR library. Finally, 37 genes that were specifically expressed in roots were screened after comparing the DEGs identified in the above-described analyses. This study provides a transcriptome sequence resource for common wild rice plants and establishes a digital gene expression profile of wild rice plants under drought conditions using the assembled transcriptome data as a reference. Several tissue-specific and drought-stress-related candidate genes were identified, representing a fully characterized transcriptome and providing a valuable resource for genetic and genomic studies in plants.

Aberrant activity of NKL homeobox gene NKX3-2 in a T-ALL subset

PubMed Central

Meyer, Corinna; Kaufmann, Maren; Zaborski, Margarete; MacLeod, Roderick A. F.; Drexler, Hans G.

2018-01-01

T-cell acute lymphoblastic leukemia (T-ALL) is a hematopoietic malignancy originating from T-cell progenitors in which differentiation is blocked at early stages. Physiological expression of specific NKL homeobox genes obeys a hematopoietic NKL-code implicated in the process of lymphopoiesis while in differentiated T-cells these genes are silenced. We propose that this developmental expression pattern underlies the observation that NKL homeobox genes are the most ubiquitous group of transcription factors deregulated in T-ALL, including TLX1, TLX3, NKX2-5 and NKX3-1. Here, we describe a novel member of the NKL homeobox gene subclass, NKX3-2 (BAPX1), which is aberrantly activated in 18% of pediatric T-ALL patients analyzed while being normally expressed in developing spleen. Identification of NKX3-2 expression in T-ALL cell line CCRF-CEM qualified these cells to model its deregulation and function in a leukemic context. Genomic and chromosomal analyses demonstrated normal configuration of the NKX3-2 locus at chromosome 4p15, thus excluding cytogenetic dysregulation. Comparative expression profiling analysis of NKX3-2 patient data revealed deregulated activity of BMP- and MAPK-signalling. These candidate pathways were experimentally confirmed to mediate aberrant NKX3-2 expression. We also show that homeobox gene SIX6, plus MIR17HG and GATA3 are downstream targets of NKX3-2 and plausibly contribute to the pathogenesis of this malignancy by suppressing T-cell differentiation. Finally, NKL homeobox gene NKX2-5 was activated by NKX3-2 in CCRF-CEM and by FOXG1 in PEER, representing mutually inhibitory activators of this translocated oncogene. Together, our findings reveal a novel oncogenic NKL homeobox gene subclass member which is aberrantly expressed in a large subset of T-ALL patients and participates in a deregulated gene network likely to arise in developing spleen. PMID:29746601

Aberrant activity of NKL homeobox gene NKX3-2 in a T-ALL subset.

PubMed

Nagel, Stefan; Meyer, Corinna; Kaufmann, Maren; Zaborski, Margarete; MacLeod, Roderick A F; Drexler, Hans G

2018-01-01

T-cell acute lymphoblastic leukemia (T-ALL) is a hematopoietic malignancy originating from T-cell progenitors in which differentiation is blocked at early stages. Physiological expression of specific NKL homeobox genes obeys a hematopoietic NKL-code implicated in the process of lymphopoiesis while in differentiated T-cells these genes are silenced. We propose that this developmental expression pattern underlies the observation that NKL homeobox genes are the most ubiquitous group of transcription factors deregulated in T-ALL, including TLX1, TLX3, NKX2-5 and NKX3-1. Here, we describe a novel member of the NKL homeobox gene subclass, NKX3-2 (BAPX1), which is aberrantly activated in 18% of pediatric T-ALL patients analyzed while being normally expressed in developing spleen. Identification of NKX3-2 expression in T-ALL cell line CCRF-CEM qualified these cells to model its deregulation and function in a leukemic context. Genomic and chromosomal analyses demonstrated normal configuration of the NKX3-2 locus at chromosome 4p15, thus excluding cytogenetic dysregulation. Comparative expression profiling analysis of NKX3-2 patient data revealed deregulated activity of BMP- and MAPK-signalling. These candidate pathways were experimentally confirmed to mediate aberrant NKX3-2 expression. We also show that homeobox gene SIX6, plus MIR17HG and GATA3 are downstream targets of NKX3-2 and plausibly contribute to the pathogenesis of this malignancy by suppressing T-cell differentiation. Finally, NKL homeobox gene NKX2-5 was activated by NKX3-2 in CCRF-CEM and by FOXG1 in PEER, representing mutually inhibitory activators of this translocated oncogene. Together, our findings reveal a novel oncogenic NKL homeobox gene subclass member which is aberrantly expressed in a large subset of T-ALL patients and participates in a deregulated gene network likely to arise in developing spleen.

Sociogenomics of Cooperation and Conflict during Colony Founding in the Fire Ant Solenopsis invicta

PubMed Central

Manfredini, Fabio; Riba-Grognuz, Oksana; Wurm, Yannick; Keller, Laurent; Shoemaker, DeWayne; Grozinger, Christina M.

2013-01-01

One of the fundamental questions in biology is how cooperative and altruistic behaviors evolved. The majority of studies seeking to identify the genes regulating these behaviors have been performed in systems where behavioral and physiological differences are relatively fixed, such as in the honey bee. During colony founding in the monogyne (one queen per colony) social form of the fire ant Solenopsis invicta, newly-mated queens may start new colonies either individually (haplometrosis) or in groups (pleometrosis). However, only one queen (the “winner”) in pleometrotic associations survives and takes the lead of the young colony while the others (the “losers”) are executed. Thus, colony founding in fire ants provides an excellent system in which to examine the genes underpinning cooperative behavior and how the social environment shapes the expression of these genes. We developed a new whole genome microarray platform for S. invicta to characterize the gene expression patterns associated with colony founding behavior. First, we compared haplometrotic queens, pleometrotic winners and pleometrotic losers. Second, we manipulated pleometrotic couples in order to switch or maintain the social ranks of the two cofoundresses. Haplometrotic and pleometrotic queens differed in the expression of genes involved in stress response, aging, immunity, reproduction and lipid biosynthesis. Smaller sets of genes were differentially expressed between winners and losers. In the second experiment, switching social rank had a much greater impact on gene expression patterns than the initial/final rank. Expression differences for several candidate genes involved in key biological processes were confirmed using qRT-PCR. Our findings indicate that, in S. invicta, social environment plays a major role in the determination of the patterns of gene expression, while the queen's physiological state is secondary. These results highlight the powerful influence of social environment on regulation of the genomic state, physiology and ultimately, social behavior of animals. PMID:23950725

Effect of mixed-Bacillus spp isolated from pustulose ark Anadara tuberculosa on growth, survival, viral prevalence and immune-related gene expression in shrimp Litopenaeus vannamei.

PubMed

Sánchez-Ortiz, Ana Claudia; Angulo, Carlos; Luna-González, Antonio; Álvarez-Ruiz, Píndaro; Mazón-Suástegui, José Manuel; Campa-Córdova, Ángel Isidro

2016-12-01

The widespread overuse of antibiotics in aquaculture has led to the emergence of antibiotic-resistance shrimp pathogens, the negative impact on shrimp gut microbiota, and the presence of antimicrobial residues in aquaculture products, with negative consequences on human health. Alternatively, probiotics have positive effects on immunological responses and productive performance of aquatic animals. In this study, three probiotic bacteria, (Bacillus licheniformis MAt32, B. subtilis MAt43 and B. subtilis subsp. subtilis GAtB1), isolated from the Anadara tuberculosa were included in diets for juvenile shrimp, Litopenaeus vannamei, to evaluate their effects on growth, survival, disease prevalence, and immune-related gene expression. Shrimp naturally infected with WSSV and IHHNV were fed with the basal diet (control, T1) and diets supplemented with four levels of bacilli probiotic mix (1:1:1) at final concentration of (T2) 1 × 10 6 , (T3) 2 × 10 6 , (T4) 4 × 10 6 , and (T5) 6 × 10 6  CFU g -1 of feed. The specific growth rate of shrimp was significantly higher in T2 than in T1 (control) treatment, and the final growth as well as the survival were similar among treated groups. The prevalence of WSSV and IHHNV infected shrimp was reduced in T2 and T4 treatments, respectively, compared with control. The mRNA expression of proPO gene was higher in treatment T4 than control. The LvToll1 gene was significantly up-regulated in treatments T4 and T5 compared to control. The SOD gene was up-regulated in treatment T5 compared to control. In contrast, the mRNA expression of the Hsp70 gene was down-regulated in treatments T4 and T5 respect to control, and the TGase gene remained unaffected by the level of bacillus probiotic mix. As conclusion, the bacilli probiotic mix (Bacillus spp.) enhanced immune-related gene expression in WSSV and IHHNV naturally infected shrimp. This is the first report of probiotic potential of bacteria isolated from A. tuberculosa on the immune response and viral prevalence in shrimp Litopenaeus vannamei. Copyright © 2016 Elsevier Ltd. All rights reserved.

Nonclassical Regulation of Transcription: Interchromosomal Interactions at the Malic enzyme Locus of Drosophila melanogaster

PubMed Central

Lum, Thomas E.; Merritt, Thomas J. S.

2011-01-01

Regulation of transcription can be a complex process in which many cis- and trans-interactions determine the final pattern of expression. Among these interactions are trans-interactions mediated by the pairing of homologous chromosomes. These trans-effects are wide ranging, affecting gene regulation in many species and creating complex possibilities in gene regulation. Here we describe a novel case of trans-interaction between alleles of the Malic enzyme (Men) locus in Drosophila melanogaster that results in allele-specific, non-additive gene expression. Using both empirical biochemical and predictive bioinformatic approaches, we show that the regulatory elements of one allele are capable of interacting in trans with, and modifying the expression of, the second allele. Furthermore, we show that nonlocal factors—different genetic backgrounds—are capable of significant interactions with individual Men alleles, suggesting that these trans-effects can be modified by both locally and distantly acting elements. In sum, these results emphasize the complexity of gene regulation and the need to understand both small- and large-scale interactions as more complete models of the role of trans-interactions in gene regulation are developed. PMID:21900270

A dynamic interplay of nucleosome and Msn2 binding regulates kinetics of gene activation and repression following stress

PubMed Central

Elfving, Nils; Chereji, Răzvan V.; Bharatula, Vasudha; Björklund, Stefan; Morozov, Alexandre V.; Broach, James R.

2014-01-01

The transcription factor Msn2 mediates a significant proportion of the environmental stress response, in which a common cohort of genes changes expression in a stereotypic fashion upon exposure to any of a wide variety of stresses. We have applied genome-wide chromatin immunoprecipitation and nucleosome profiling to determine where Msn2 binds under stressful conditions and how that binding affects, and is affected by, nucleosome positioning. We concurrently determined the effect of Msn2 activity on gene expression following stress and demonstrated that Msn2 stimulates both activation and repression. We found that some genes responded to both intermittent and continuous Msn2 nuclear occupancy while others responded only to continuous occupancy. Finally, these studies document a dynamic interplay between nucleosomes and Msn2 such that nucleosomes can restrict access of Msn2 to its canonical binding sites while Msn2 can promote reposition, expulsion and recruitment of nucleosomes to alter gene expression. This interplay may allow the cell to discriminate between different types of stress signaling. PMID:24598258

Gene Delivery to the Airway

PubMed Central

Keiser, Nicholas W.; Engelhardt, John F.

2013-01-01

This unit describes generation of and gene transfer to several commonly used airway models. Isolation and transduction of primary airway epithelial cells are first described. Next, the preparation of polarized airway epithelial monolayers is outlined. Transduction of these polarized cells is also described. Methods are presented for generation of tracheal xenografts as well as both ex vivo and in vivo gene transfer to these xenografts. Finally, a method for in vivo gene delivery to the lungs of rodents is included. Methods for evaluating transgene expression are given in the support protocols. PMID:23853081

Down-regulation of PRKCB1 expression in Han Chinese patients with subsyndromal symptomatic depression.

PubMed

Guo, Xiaoyun; Li, Zezhi; Zhang, Chen; Yi, Zhenghui; Li, Haozhe; Cao, Lan; Yuan, Chengmei; Hong, Wu; Wu, Zhiguo; Peng, Daihui; Chen, Jun; Xia, Weiping; Zhao, Guoqing; Wang, Fan; Yu, Shunying; Cui, Donghong; Xu, Yifeng; Golam, Chowdhury M I; Smith, Alicia K; Wang, Tong; Fang, Yiru

2015-10-01

Subsyndromal symptomatic depression (SSD) is a common disease with significant social dysfunction. However, SSD is still not well understood and the pathophysiology of it remains unclear. We classified 48 candidate genes for SSD according to our previous study into clusters and pathways using DAVID Bioinformatics Functional Annotation Tool. We further replicated the result by using real-time Quantitative PCR (qPCR) studies to examine the expression of identified genes (i.e., STAT5b, PKCB1, ABL1 and NRAS) in another group of Han Chinese patients with SSD (n = 50). We further validated the result by examining PRKCB1 expression collected from MDD patients (n = 20). To test whether a deficit in PRKCB1 expression leads to dysregulation in PRKCB1 dependent transcript networks, we tested mRNA expression levels for the remaining 44 genes out of 48 genes in SSD patients. Finally, the power of discovery was improved by incorporating information from Quantitative Trait (eQTL) analysis. The results showed that the PRCKB1 gene expression in peripheral blood mononuclear cells (PBMC) was 33.3% down-regulated in SSD patients (n = 48, t = 3.202, p = 0.002), and a more dramatic (n = 17, 49%) down-regulation in MDD patients than control (n = 49, t = 2.114, p = 0.001). We also identified 37 genes that displayed a strong correlation with PRKCB1 mRNA expression levels in SSD patients. The expression of PRKCB1 was regulated by multiple single nucleotide polymorphisms (SNPs) both at the transcript level and exon level. In conclusion, we first found a significant decrease of PRCKB1 mRNA expression in SSD, suggesting PRKCB1 might be the candidate gene and biomarker for SSD. Copyright © 2015 Elsevier Ltd. All rights reserved.

Constitutive expression of a grapevine polygalacturonase-inhibiting protein affects gene expression and cell wall properties in uninfected tobacco

PubMed Central

2011-01-01

Background Polygalacturonase-inhibiting proteins (PGIPs) directly limit the effective ingress of fungal pathogens by inhibiting cell wall-degrading endopolygalacturonases (ePGs). Transgenic tobacco plants over-expressing grapevine (Vitis vinifera) Vvpgip1 have previously been shown to be resistant to Botrytis infection. In this study we characterized two of these PGIP over-expressing lines with known resistance phenotypes by gene expression and hormone profiling in the absence of pathogen infection. Results Global gene expression was performed by a cross-species microarray approach using a potato cDNA microarray. The degree of potential cross-hybridization between probes was modeled by a novel computational workflow designed in-house. Probe annotations were updated by predicting probe-to-transcript hybridizations and combining information derived from other plant species. Comparing uninfected Vvpgip1-overexpressing lines to wild-type (WT), 318 probes showed significant change in expression. Functional groups of genes involved in metabolism and associated to the cell wall were identified and consequent cell wall analysis revealed increased lignin-levels in the transgenic lines, but no major differences in cell wall-derived polysaccharides. GO enrichment analysis also identified genes responsive to auxin, which was supported by elevated indole-acetic acid (IAA) levels in the transgenic lines. Finally, a down-regulation of xyloglucan endotransglycosylase/hydrolases (XTHs), which are important in cell wall remodeling, was linked to a decrease in total XTH activity. Conclusions This evaluation of PGIP over-expressing plants performed under pathogen-free conditions to exclude the classical PGIP-ePG inhibition interaction indicates additional roles for PGIPs beyond the inhibition of ePGs. PMID:22078230

A Double Selection Approach to Achieve Specific Expression of Toxin Genes for Ovarian Cancer Gene Therapy

DTIC Science & Technology

2006-11-01

fibers that served as the junction for the replacement of the OAdV7 tail domain, as well as other common sequences, is highlighted. The final Ad5Luc1-OvF...Fold increase in luciferase activity vs. Ad5 b Reference CHO Hamster ovary L/N 22 Soudais et al., 2000 RD Rhabdomyosarcoma L/N 1.5 Dmitriev et al., 1998...of OV-3 cells (human ovarian cancer, 23-fold) and CAR-deficient CHO cells (Chinese hamster ovary, 22-fold), suggesting that RD cells do not express

Overexpression of Transcription Factor Sp1 Leads to Gene Expression Perturbations and Cell Cycle Inhibition

PubMed Central

Deniaud, Emmanuelle; Baguet, Joël; Chalard, Roxane; Blanquier, Bariza; Brinza, Lilia; Meunier, Julien; Michallet, Marie-Cécile; Laugraud, Aurélie; Ah-Soon, Claudette; Wierinckx, Anne; Castellazzi, Marc; Lachuer, Joël; Gautier, Christian

2009-01-01

Background The ubiquitous transcription factor Sp1 regulates the expression of a vast number of genes involved in many cellular functions ranging from differentiation to proliferation and apoptosis. Sp1 expression levels show a dramatic increase during transformation and this could play a critical role for tumour development or maintenance. Although Sp1 deregulation might be beneficial for tumour cells, its overexpression induces apoptosis of untransformed cells. Here we further characterised the functional and transcriptional responses of untransformed cells following Sp1 overexpression. Methodology and Principal Findings We made use of wild-type and DNA-binding-deficient Sp1 to demonstrate that the induction of apoptosis by Sp1 is dependent on its capacity to bind DNA. Genome-wide expression profiling identified genes involved in cancer, cell death and cell cycle as being enriched among differentially expressed genes following Sp1 overexpression. In silico search to determine the presence of Sp1 binding sites in the promoter region of modulated genes was conducted. Genes that contained Sp1 binding sites in their promoters were enriched among down-regulated genes. The endogenous sp1 gene is one of the most down-regulated suggesting a negative feedback loop induced by overexpressed Sp1. In contrast, genes containing Sp1 binding sites in their promoters were not enriched among up-regulated genes. These results suggest that the transcriptional response involves both direct Sp1-driven transcription and indirect mechanisms. Finally, we show that Sp1 overexpression led to a modified expression of G1/S transition regulatory genes such as the down-regulation of cyclin D2 and the up-regulation of cyclin G2 and cdkn2c/p18 expression. The biological significance of these modifications was confirmed by showing that the cells accumulated in the G1 phase of the cell cycle before the onset of apoptosis. Conclusion This study shows that the binding to DNA of overexpressed Sp1 induces an inhibition of cell cycle progression that precedes apoptosis and a transcriptional response targeting genes containing Sp1 binding sites in their promoter or not suggesting both direct Sp1-driven transcription and indirect mechanisms. PMID:19753117

Development of a rapid high-efficiency scalable process for acetylated Sus scrofa cationic trypsin production from Escherichia coli inclusion bodies.

PubMed

Zhao, Mingzhi; Wu, Feilin; Xu, Ping

2015-12-01

Trypsin is one of the most important enzymatic tools in proteomics and biopharmaceutical studies. Here, we describe the complete recombinant expression and purification from a trypsinogen expression vector construct. The Sus scrofa cationic trypsin gene with a propeptide sequence was optimized according to Escherichia coli codon-usage bias and chemically synthesized. The gene was inserted into pET-11c plasmid to yield an expression vector. Using high-density E. coli fed-batch fermentation, trypsinogen was expressed in inclusion bodies at 1.47 g/L. The inclusion body was refolded with a high yield of 36%. The purified trypsinogen was then activated to produce trypsin. To address stability problems, the trypsin thus produced was acetylated. The final product was generated upon gel filtration. The final yield of acetylated trypsin was 182 mg/L from a 5-L fermenter. Our acetylated trypsin product demonstrated higher BAEE activity (30,100 BAEE unit/mg) than a commercial product (9500 BAEE unit/mg, Promega). It also demonstrated resistance to autolysis. This is the first report of production of acetylated recombinant trypsin that is stable and suitable for scale-up. Copyright © 2015 Elsevier Inc. All rights reserved.

Developmental Regulation of Gonadotropin-releasing Hormone Gene Expression by the MSX and DLX Homeodomain Protein Families*

PubMed Central

Givens, Marjory L.; Rave-Harel, Naama; Goonewardena, Vinodha D.; Kurotani, Reiko; Berdy, Sara E.; Swan, Christo H.; Rubenstein, John L. R.; Robert, Benoit; Mellon, Pamela L.

2010-01-01

Gonadotropin-releasing hormone (GnRH) is the central regulator of the hypothalamic-pituitary-gonadal axis, controlling sexual maturation and fertility in diverse species from fish to humans. GnRH gene expression is limited to a discrete population of neurons that migrate through the nasal region into the hypothalamus during embryonic development. The GnRH regulatory region contains four conserved homeodomain binding sites (ATTA) that are essential for basal promoter activity and cell-specific expression of the GnRH gene. MSX and DLX are members of the Antennapedia class of non-Hox homeodomain transcription factors that regulate gene expression and influence development of the craniofacial structures and anterior forebrain. Here, we report that expression patterns of the Msx and Dlx families of homeodomain transcription factors largely coincide with the migratory route of GnRH neurons and co-express with GnRH in neurons during embryonic development. In addition, MSX and DLX family members bind directly to the ATTA consensus sequences and regulate transcriptional activity of the GnRH promoter. Finally, mice lacking MSX1 or DLX1 and 2 show altered numbers of GnRH-expressing cells in regions where these factors likely function. These findings strongly support a role for MSX and DLX in contributing to spatiotemporal regulation of GnRH transcription during development. PMID:15743757

Discovering Single Nucleotide Polymorphisms Regulating Human Gene Expression Using Allele Specific Expression from RNA-seq Data

PubMed Central

Kang, Eun Yong; Martin, Lisa J.; Mangul, Serghei; Isvilanonda, Warin; Zou, Jennifer; Ben-David, Eyal; Han, Buhm; Lusis, Aldons J.; Shifman, Sagiv; Eskin, Eleazar

2016-01-01

The study of the genetics of gene expression is of considerable importance to understanding the nature of common, complex diseases. The most widely applied approach to identifying relationships between genetic variation and gene expression is the expression quantitative trait loci (eQTL) approach. Here, we increased the computational power of eQTL with an alternative and complementary approach based on analyzing allele specific expression (ASE). We designed a novel analytical method to identify cis-acting regulatory variants based on genome sequencing and measurements of ASE from RNA-sequencing (RNA-seq) data. We evaluated the power and resolution of our method using simulated data. We then applied the method to map regulatory variants affecting gene expression in lymphoblastoid cell lines (LCLs) from 77 unrelated northern and western European individuals (CEU), which were part of the HapMap project. A total of 2309 SNPs were identified as being associated with ASE patterns. The SNPs associated with ASE were enriched within promoter regions and were significantly more likely to signal strong evidence for a regulatory role. Finally, among the candidate regulatory SNPs, we identified 108 SNPs that were previously associated with human immune diseases. With further improvements in quantifying ASE from RNA-seq, the application of our method to other datasets is expected to accelerate our understanding of the biological basis of common diseases. PMID:27765809

The effect of macromolecular crowding on mobility of biomolecules, association kinetics and gene expression in living cells

NASA Astrophysics Data System (ADS)

Tabaka, Marcin; Kalwarczyk, Tomasz; Szymanski, Jedrzej; Hou, Sen; Hołyst, Robert

2014-09-01

We discuss a quantitative influence of macromolecular crowding on biological processes: motion, bimolecular reactions, and gene expression in prokaryotic and eukaryotic cells. We present scaling laws relating diffusion coefficient of an object moving in a cytoplasm of cells to a size of this object and degree of crowding. Such description leads to the notion of the length scale dependent viscosity characteristic for all living cells. We present an application of the length-scale dependent viscosity model to the description of motion in the cytoplasm of both eukaryotic and prokaryotic living cells. We compare the model with all recent data on diffusion of nanoscopic objects in HeLa, and E. coli cells. Additionally a description of the mobility of molecules in cell nucleus is presented. Finally we discuss the influence of crowding on the bimolecular association rates and gene expression in living cells.

Selection of Reference Genes for Expression Studies in Diaphorina citri (Hemiptera: Liviidae).

PubMed

Bassan, Meire Menezes; Angelotti-Mendonc A, Je Ssika; Alves, Gustavo Rodrigues; Yamamoto, Pedro Takao; Moura O Filho, Francisco de Assis Alves

2017-12-05

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Liviidae), is considered the main vector of the bacteria associated with huanglongbing, a very serious disease that has threatened the world citrus industry. The absence of efficient control management protocols, including a lack of resistant cultivars, has led to the development of different approaches to study this pathosystem. The production of resistant genotypes relies on D. citri gene expression analyses by RT-qPCR to assess control of the vector population. High-quality, reliable RT-qPCR analyses depend upon proper reference gene selection and validation. However, adequate D. citri reference genes have not yet been identified. In the present study, we evaluated the genes EF 1-α, ACT, GAPDH, RPL7, RPL17, and TUB as candidate reference genes for this insect. Gene expression stability was evaluated using the mathematical algorithms deltaCt, NormFinder, BestKeeper, and geNorm, at five insect developmental stages, grown on two different plant hosts [Citrus sinensis (L.) Osbeck (Sapindales: Rutaceae) and Murraya paniculata (L.) Jack (Sapindales: Rutaceae)]. The final gene ranking was calculated using RefFinder software, and the V-ATPase-A gene was selected for validation. According to our results, two reference genes are recommended when different plant hosts and developmental stages are considered. Considering gene expression studies in D. citri grown on M. paniculata, regardless of the insect developmental stage, GAPDH and RPL7 have the best fit as reference genes in RT-qPCR analyses, whereas GAPDH and EF 1-α are recommended as reference genes in insect studies using C. sinensis. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Analysis of Gene Expression and Physiological Responses in Three Mexican Maize Landraces under Drought Stress and Recovery Irrigation

PubMed Central

Hayano-Kanashiro, Corina; Calderón-Vázquez, Carlos; Ibarra-Laclette, Enrique; Herrera-Estrella, Luis; Simpson, June

2009-01-01

Background Drought is one of the major constraints for plant productivity worldwide. Different mechanisms of drought-tolerance have been reported for several plant species including maize. However, the differences in global gene expression between drought-tolerant and susceptible genotypes and their relationship to physiological adaptations to drought are largely unknown. The study of the differences in global gene expression between tolerant and susceptible genotypes could provide important information to design more efficient breeding programs to produce maize varieties better adapted to water limiting conditions. Methodology/Principal Findings Changes in physiological responses and gene expression patterns were studied under drought stress and recovery in three Mexican maize landraces which included two drought tolerant (Cajete criollo and Michoacán 21) and one susceptible (85-2) genotypes. Photosynthesis, stomatal conductance, soil and leaf water potentials were monitored throughout the experiment and microarray analysis was carried out on transcripts obtained at 10 and 17 days following application of stress and after recovery irrigation. The two tolerant genotypes show more drastic changes in global gene expression which correlate with different physiological mechanisms of adaptation to drought. Differences in the kinetics and number of up- and down-regulated genes were observed between the tolerant and susceptible maize genotypes, as well as differences between the two tolerant genotypes. Interestingly, the most dramatic differences between the tolerant and susceptible genotypes were observed during recovery irrigation, suggesting that the tolerant genotypes activate mechanisms that allow more efficient recovery after a severe drought. Conclusions/Significance A correlation between levels of photosynthesis and transcription under stress was observed and differences in the number, type and expression levels of transcription factor families were also identified under drought and recovery between the three maize landraces. Gene expression analysis suggests that the drought tolerant landraces have a greater capacity to rapidly modulate more genes under drought and recovery in comparison to the susceptible landrace. Modulation of a greater number of differentially expressed genes of different TF gene families is an important characteristic of the tolerant genotypes. Finally, important differences were also noted between the tolerant landraces that underlie different mechanisms of achieving tolerance. PMID:19888455

Limited Contribution of DNA Methylation Variation to Expression Regulation in Arabidopsis thaliana.

PubMed

Meng, Dazhe; Dubin, Manu; Zhang, Pei; Osborne, Edward J; Stegle, Oliver; Clark, Richard M; Nordborg, Magnus

2016-07-01

The extent to which epigenetic variation affects complex traits in natural populations is not known. We addressed this question using transcriptome and DNA methylation data from a sample of 135 sequenced A. thaliana accessions. Across individuals, expression was significantly associated with cis-methylation for hundreds of genes, and many of these associations remained significant after taking SNP effects into account. The pattern of correlations differed markedly between gene body methylation and transposable element methylation. The former was usually positively correlated with expression, and the latter usually negatively correlated, although exceptions were found in both cases. Finally, we developed graphical models of causality that adapt to a sample with heavy population structure, and used them to show that while methylation appears to affect gene expression more often than expression affects methylation, there is also strong support for both being independently controlled. In conclusion, although we find clear evidence for epigenetic regulation, both the number of loci affected and the magnitude of the effects appear to be small compared to the effect of SNPs.

A gene expression analysis of cell wall biosynthetic genes in Malus × domestica infected by ‘Candidatus Phytoplasma mali’

PubMed Central

Guerriero, Gea; Giorno, Filomena; Ciccotti, Anna Maria; Schmidt, Silvia; Baric, Sanja

2016-01-01

Apple proliferation (AP) represents a serious threat to several fruit-growing areas and is responsible for great economic losses. Several studies have highlighted the key role played by the cell wall in response to pathogen attack. The existence of a cell wall integrity signaling pathway which senses perturbations in the cell wall architecture upon abiotic/biotic stresses and activates specific defence responses has been widely demonstrated in plants. More recently a role played by cell wall-related genes has also been reported in plants infected by phytoplasmas. With the aim of shedding light on the cell wall response to AP disease in the economically relevant fruit-tree Malus × domestica Borkh., we investigated the expression of the cellulose (CesA) and callose synthase (CalS) genes in different organs (i.e., leaves, roots and branch phloem) of healthy and infected symptomatic outdoor-grown trees, sampled over the course of two time points (i.e., spring and autumn 2011), as well as in in vitro micropropagated control and infected plantlets. A strong up-regulation in the expression of cell wall biosynthetic genes was recorded in roots from infected trees. Secondary cell wall CesAs showed up-regulation in the phloem tissue from branches of infected plants, while either a down-regulation of some genes or no major changes were observed in the leaves. Micropropagated plantlets also showed an increase in cell wall-related genes and constitute a useful system for a general assessment of gene expression analysis upon phytoplasma infection. Finally, we also report the presence of several ‘knot’-like structures along the roots of infected apple trees and discuss the occurrence of this interesting phenotype in relation to the gene expression results and the modalities of phytoplasma diffusion. PMID:23086810

Developmental expression of high molecular weight tropomyosin isoforms in Mesocestoides corti.

PubMed

Koziol, Uriel; Costábile, Alicia; Domínguez, María Fernanda; Iriarte, Andrés; Alvite, Gabriela; Kun, Alejandra; Castillo, Estela

2011-02-01

Tropomyosins are a family of actin-binding proteins with diverse roles in actin filament function. One of the best characterized roles is the regulation of muscle contraction. Tropomyosin isoforms can be generated from different genes, and from alternative promoters and alternative splicing from the same gene. In this work, we have isolated sequences for tropomyosin isoforms from the cestode Mesocestoides corti, and searched for tropomyosin genes and isoforms in other flatworms. Two genes are conserved in the cestodes M. corti and Echinococcus multilocularis, and in the trematode Schistosoma mansoni. Both genes have the same structure, and each gene gives rise to at least two different isoforms, a high molecular weight (HMW) and a low molecular weight (LMW) one. Because most exons are duplicated and spliced in a mutually exclusive fashion, isoforms from one gene only share one exon and are highly divergent. The gene duplication preceded the divergence of neodermatans and the planarian Schmidtea mediterranea. Further duplications occurred in Schmidtea, coupled to the selective loss of duplicated exons, resulting in genes that only code for HMW or LMW isoforms. A polyclonal antibody raised against a HMW tropomyosin from Echinococcus granulosus was demonstrated to specifically recognize HMW tropomyosin isoforms of M. corti, and used to study their expression during segmentation. HMW tropomyosins are expressed in muscle layers, with very low or absent levels in other tissues. No expression of HMW tropomyosins is present in early or late genital primordia, and expression only begins once muscle fibers develop in the genital ducts. Therefore, HMW tropomyosins are markers for the development of muscles during the final differentiation of genital primordia. Copyright © 2010 Elsevier B.V. All rights reserved.

Electrotransformation and expression of bacterial genes encoding hygromycin phosphotransferase and beta-galactosidase in the pathogenic fungus Histoplasma capsulatum.

PubMed

Woods, J P; Heinecke, E L; Goldman, W E

1998-04-01

We developed an efficient electrotransformation system for the pathogenic fungus Histoplasma capsulatum and used it to examine the effects of features of the transforming DNA on transformation efficiency and fate of the transforming DNA and to demonstrate fungal expression of two recombinant Escherichia coli genes, hph and lacZ. Linearized DNA and plasmids containing Histoplasma telomeric sequences showed the greatest transformation efficiencies, while the plasmid vector had no significant effect, nor did the derivation of the selectable URA5 marker (native Histoplasma gene or a heterologous Podospora anserina gene). Electrotransformation resulted in more frequent multimerization, other modification, or possibly chromosomal integration of transforming telomeric plasmids when saturating amounts of DNA were used, but this effect was not observed with smaller amounts of transforming DNA. We developed another selection system using a hygromycin B resistance marker from plasmid pAN7-1, consisting of the E. coli hph gene flanked by Aspergillus nidulans promoter and terminator sequences. Much of the heterologous fungal sequences could be removed without compromising function in H. capsulatum, allowing construction of a substantially smaller effective marker fragment. Transformation efficiency increased when nonselective conditions were maintained for a time after electrotransformation before selection with the protein synthesis inhibitor hygromycin B was imposed. Finally, we constructed a readily detectable and quantifiable reporter gene by fusing Histoplasma URA5 with E. coli lacZ, resulting in expression of functional beta-galactosidase in H. capsulatum. Demonstration of expression of bacterial genes as effective selectable markers and reporters, together with a highly efficient electrotransformation system, provide valuable approaches for molecular genetic analysis and manipulation of H. capsulatum, which have proven useful for examination of targeted gene disruption, regulated gene expression, and potential virulence determinants in this fungus.

Aberrant expression of NKL homeobox gene HLX in Hodgkin lymphoma.

PubMed

Nagel, Stefan; Pommerenke, Claudia; Meyer, Corinna; Kaufmann, Maren; MacLeod, Roderick A F; Drexler, Hans G

2018-03-06

NKL homeobox genes are basic regulators of cell and tissue differentiation, many acting as oncogenes in T-cell leukemia. Recently, we described an hematopoietic NKL-code comprising six particular NKL homeobox genes expressed in hematopoietic stem cells and lymphoid progenitors, unmasking their physiological roles in the development of these cell types. Hodgkin lymphoma (HL) is a B-cell malignancy showing aberrant activity of several developmental genes resulting in disturbed B-cell differentiation. To examine potential concordances in abnormal lymphoid differentiation of T- and B-cell malignancies we analyzed the expression of the hematopoietic NKL-code associated genes in HL, comprising HHEX, HLX, MSX1, NKX2-3, NKX3-1 and NKX6-3. Our approach revealed aberrant HLX activity in 8 % of classical HL patients and additionally in HL cell line L-540. Accordingly, to identify upstream regulators and downstream target genes of HLX we used L-540 cells as a model and performed chromosome and genome analyses, comparative expression profiling and functional assays via knockdown and overexpression experiments therein. These investigations excluded chromosomal rearrangements of the HLX locus at 1q41 and demonstrated that STAT3 operated directly as transcriptional activator of the HLX gene. Moreover, subcellular analyses showed highly enriched STAT3 protein in the nucleus of L-540 cells which underwent cytoplasmic translocation by repressing deacetylation. Finally, HLX inhibited transcription of B-cell differentiation factors MSX1, BCL11A and SPIB and of pro-apoptotic factor BCL2L11/BIM, thereby suppressing Etoposide-induced cell death. Collectively, we propose that aberrantly expressed NKL homeobox gene HLX is part of a pathological gene network in HL, driving deregulated B-cell differentiation and survival.

HPV Integration in HNSCC Correlates with Survival Outcomes, Immune Response Signatures, and Candidate Drivers.

PubMed

Koneva, Lada A; Zhang, Yanxiao; Virani, Shama; Hall, Pelle B; McHugh, Jonathan B; Chepeha, Douglas B; Wolf, Gregory T; Carey, Thomas E; Rozek, Laura S; Sartor, Maureen A

2018-01-01

The incidence of human papillomavirus (HPV)-related oropharynx cancer has steadily increased over the past two decades and now represents a majority of oropharyngeal cancer cases. Integration of the HPV genome into the host genome is a common event during carcinogenesis that has clinically relevant effects if the viral early genes are transcribed. Understanding the impact of HPV integration on clinical outcomes of head and neck squamous cell carcinoma (HNSCC) is critical for implementing deescalated treatment approaches for HPV + HNSCC patients. RNA sequencing (RNA-seq) data from HNSCC tumors ( n = 84) were used to identify and characterize expressed integration events, which were overrepresented near known head and neck, lung, and urogenital cancer genes. Five genes were recurrent, including CD274 (PD-L1) A significant number of genes detected to have integration events were found to interact with Tp63, ETS, and/or FOX1A. Patients with no detected integration had better survival than integration-positive and HPV - patients. Furthermore, integration-negative tumors were characterized by strongly heightened signatures for immune cells, including CD4 + , CD3 + , regulatory, CD8 + T cells, NK cells, and B cells, compared with integration-positive tumors. Finally, genes with elevated expression in integration-negative specimens were strongly enriched with immune-related gene ontology terms, while upregulated genes in integration-positive tumors were enriched for keratinization, RNA metabolism, and translation. Implications: These findings demonstrate the clinical relevancy of expressed HPV integration, which is characterized by a change in immune response and/or aberrant expression of the integration-harboring cancer-related genes, and suggest strong natural selection for tumor cells with expressed integration events in key carcinogenic genes. Mol Cancer Res; 16(1); 90-102. ©2017 AACR . ©2017 American Association for Cancer Research.

Integrative Approach to Pain Genetics Identifies Pain Sensitivity Loci across Diseases

PubMed Central

Ruau, David; Dudley, Joel T.; Chen, Rong; Phillips, Nicholas G.; Swan, Gary E.; Lazzeroni, Laura C.; Clark, J. David

2012-01-01

Identifying human genes relevant for the processing of pain requires difficult-to-conduct and expensive large-scale clinical trials. Here, we examine a novel integrative paradigm for data-driven discovery of pain gene candidates, taking advantage of the vast amount of existing disease-related clinical literature and gene expression microarray data stored in large international repositories. First, thousands of diseases were ranked according to a disease-specific pain index (DSPI), derived from Medical Subject Heading (MESH) annotations in MEDLINE. Second, gene expression profiles of 121 of these human diseases were obtained from public sources. Third, genes with expression variation significantly correlated with DSPI across diseases were selected as candidate pain genes. Finally, selected candidate pain genes were genotyped in an independent human cohort and prospectively evaluated for significant association between variants and measures of pain sensitivity. The strongest signal was with rs4512126 (5q32, ABLIM3, P = 1.3×10−10) for the sensitivity to cold pressor pain in males, but not in females. Significant associations were also observed with rs12548828, rs7826700 and rs1075791 on 8q22.2 within NCALD (P = 1.7×10−4, 1.8×10−4, and 2.2×10−4 respectively). Our results demonstrate the utility of a novel paradigm that integrates publicly available disease-specific gene expression data with clinical data curated from MEDLINE to facilitate the discovery of pain-relevant genes. This data-derived list of pain gene candidates enables additional focused and efficient biological studies validating additional candidates. PMID:22685391

Drug-Path: a database for drug-induced pathways

PubMed Central

Zeng, Hui; Cui, Qinghua

2015-01-01

Some databases for drug-associated pathways have been built and are publicly available. However, the pathways curated in most of these databases are drug-action or drug-metabolism pathways. In recent years, high-throughput technologies such as microarray and RNA-sequencing have produced lots of drug-induced gene expression profiles. Interestingly, drug-induced gene expression profile frequently show distinct patterns, indicating that drugs normally induce the activation or repression of distinct pathways. Therefore, these pathways contribute to study the mechanisms of drugs and drug-repurposing. Here, we present Drug-Path, a database of drug-induced pathways, which was generated by KEGG pathway enrichment analysis for drug-induced upregulated genes and downregulated genes based on drug-induced gene expression datasets in Connectivity Map. Drug-Path provides user-friendly interfaces to retrieve, visualize and download the drug-induced pathway data in the database. In addition, the genes deregulated by a given drug are highlighted in the pathways. All data were organized using SQLite. The web site was implemented using Django, a Python web framework. Finally, we believe that this database will be useful for related researches. Database URL: http://www.cuilab.cn/drugpath PMID:26130661

Drug-Path: a database for drug-induced pathways.

PubMed

Zeng, Hui; Qiu, Chengxiang; Cui, Qinghua

2015-01-01

Some databases for drug-associated pathways have been built and are publicly available. However, the pathways curated in most of these databases are drug-action or drug-metabolism pathways. In recent years, high-throughput technologies such as microarray and RNA-sequencing have produced lots of drug-induced gene expression profiles. Interestingly, drug-induced gene expression profile frequently show distinct patterns, indicating that drugs normally induce the activation or repression of distinct pathways. Therefore, these pathways contribute to study the mechanisms of drugs and drug-repurposing. Here, we present Drug-Path, a database of drug-induced pathways, which was generated by KEGG pathway enrichment analysis for drug-induced upregulated genes and downregulated genes based on drug-induced gene expression datasets in Connectivity Map. Drug-Path provides user-friendly interfaces to retrieve, visualize and download the drug-induced pathway data in the database. In addition, the genes deregulated by a given drug are highlighted in the pathways. All data were organized using SQLite. The web site was implemented using Django, a Python web framework. Finally, we believe that this database will be useful for related researches. © The Author(s) 2015. Published by Oxford University Press.

Prediction of epigenetically regulated genes in breast cancer cell lines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loss, Leandro A; Sadanandam, Anguraj; Durinck, Steffen

Methylation of CpG islands within the DNA promoter regions is one mechanism that leads to aberrant gene expression in cancer. In particular, the abnormal methylation of CpG islands may silence associated genes. Therefore, using high-throughput microarrays to measure CpG island methylation will lead to better understanding of tumor pathobiology and progression, while revealing potentially new biomarkers. We have examined a recently developed high-throughput technology for measuring genome-wide methylation patterns called mTACL. Here, we propose a computational pipeline for integrating gene expression and CpG island methylation profles to identify epigenetically regulated genes for a panel of 45 breast cancer cell lines,more » which is widely used in the Integrative Cancer Biology Program (ICBP). The pipeline (i) reduces the dimensionality of the methylation data, (ii) associates the reduced methylation data with gene expression data, and (iii) ranks methylation-expression associations according to their epigenetic regulation. Dimensionality reduction is performed in two steps: (i) methylation sites are grouped across the genome to identify regions of interest, and (ii) methylation profles are clustered within each region. Associations between the clustered methylation and the gene expression data sets generate candidate matches within a fxed neighborhood around each gene. Finally, the methylation-expression associations are ranked through a logistic regression, and their significance is quantified through permutation analysis. Our two-step dimensionality reduction compressed 90% of the original data, reducing 137,688 methylation sites to 14,505 clusters. Methylation-expression associations produced 18,312 correspondences, which were used to further analyze epigenetic regulation. Logistic regression was used to identify 58 genes from these correspondences that showed a statistically signifcant negative correlation between methylation profles and gene expression in the panel of breast cancer cell lines. Subnetwork enrichment of these genes has identifed 35 common regulators with 6 or more predicted markers. In addition to identifying epigenetically regulated genes, we show evidence of differentially expressed methylation patterns between the basal and luminal subtypes. Our results indicate that the proposed computational protocol is a viable platform for identifying epigenetically regulated genes. Our protocol has generated a list of predictors including COL1A2, TOP2A, TFF1, and VAV3, genes whose key roles in epigenetic regulation is documented in the literature. Subnetwork enrichment of these predicted markers further suggests that epigenetic regulation of individual genes occurs in a coordinated fashion and through common regulators.« less

Inferring Time-Varying Network Topologies from Gene Expression Data

PubMed Central

2007-01-01

Most current methods for gene regulatory network identification lead to the inference of steady-state networks, that is, networks prevalent over all times, a hypothesis which has been challenged. There has been a need to infer and represent networks in a dynamic, that is, time-varying fashion, in order to account for different cellular states affecting the interactions amongst genes. In this work, we present an approach, regime-SSM, to understand gene regulatory networks within such a dynamic setting. The approach uses a clustering method based on these underlying dynamics, followed by system identification using a state-space model for each learnt cluster—to infer a network adjacency matrix. We finally indicate our results on the mouse embryonic kidney dataset as well as the T-cell activation-based expression dataset and demonstrate conformity with reported experimental evidence. PMID:18309363

Inferring time-varying network topologies from gene expression data.

PubMed

Rao, Arvind; Hero, Alfred O; States, David J; Engel, James Douglas

2007-01-01

Most current methods for gene regulatory network identification lead to the inference of steady-state networks, that is, networks prevalent over all times, a hypothesis which has been challenged. There has been a need to infer and represent networks in a dynamic, that is, time-varying fashion, in order to account for different cellular states affecting the interactions amongst genes. In this work, we present an approach, regime-SSM, to understand gene regulatory networks within such a dynamic setting. The approach uses a clustering method based on these underlying dynamics, followed by system identification using a state-space model for each learnt cluster--to infer a network adjacency matrix. We finally indicate our results on the mouse embryonic kidney dataset as well as the T-cell activation-based expression dataset and demonstrate conformity with reported experimental evidence.

Identifying candidate driver genes by integrative ovarian cancer genomics data

NASA Astrophysics Data System (ADS)

Lu, Xinguo; Lu, Jibo

2017-08-01

Integrative analysis of molecular mechanics underlying cancer can distinguish interactions that cannot be revealed based on one kind of data for the appropriate diagnosis and treatment of cancer patients. Tumor samples exhibit heterogeneity in omics data, such as somatic mutations, Copy Number Variations CNVs), gene expression profiles and so on. In this paper we combined gene co-expression modules and mutation modulators separately in tumor patients to obtain the candidate driver genes for resistant and sensitive tumor from the heterogeneous data. The final list of modulators identified are well known in biological processes associated with ovarian cancer, such as CCL17, CACTIN, CCL16, CCL22, APOB, KDF1, CCL11, HNF1B, LRG1, MED1 and so on, which can help to facilitate the discovery of biomarkers, molecular diagnostics, and drug discovery.

Three distinct cell populations express extracellular matrix proteins and increase in number during skeletal muscle fibrosis.

PubMed

Chapman, Mark A; Mukund, Kavitha; Subramaniam, Shankar; Brenner, David; Lieber, Richard L

2017-02-01

Tissue extracellular matrix (ECM) provides structural support and creates unique environments for resident cells (Bateman JF, Boot-Handford RP, Lamandé SR. Nat Rev Genet 10: 173-183, 2009; Kjaer M. Physiol Rev 84: 649-98, 2004). However, the identities of cells responsible for creating specific ECM components have not been determined. In striated muscle, the identity of these cells becomes important in disease when ECM changes result in fibrosis and subsequent increased tissue stiffness and dysfunction. Here we describe a novel approach to isolate and identify cells that maintain the ECM in both healthy and fibrotic muscle. Using a collagen I reporter mouse, we show that there are three distinct cell populations that express collagen I in both healthy and fibrotic skeletal muscle. Interestingly, the number of collagen I-expressing cells in all three cell populations increases proportionally in fibrotic muscle, indicating that all cell types participate in the fibrosis process. Furthermore, while some profibrotic ECM and ECM-associated genes are significantly upregulated in fibrotic muscle, the fibrillar collagen gene expression profile is not qualitatively altered. This suggests that muscle fibrosis in this model results from an increased number of collagen I-expressing cells and not the initiation of a specific fibrotic collagen gene expression program. Finally, in fibrotic muscle, we show that these collagen I-expressing cell populations differentially express distinct ECM proteins-fibroblasts express the fibrillar components of ECM, fibro/adipogenic progenitors cells differentially express basal laminar proteins, and skeletal muscle progenitor cells differentially express genes important for the satellite cell. Copyright © 2017 the American Physiological Society.

Three distinct cell populations express extracellular matrix proteins and increase in number during skeletal muscle fibrosis

PubMed Central

Chapman, Mark A.; Mukund, Kavitha; Subramaniam, Shankar; Brenner, David

2017-01-01

Tissue extracellular matrix (ECM) provides structural support and creates unique environments for resident cells (Bateman JF, Boot-Handford RP, Lamandé SR. Nat Rev Genet 10: 173–183, 2009; Kjaer M. Physiol Rev 84: 649–98, 2004). However, the identities of cells responsible for creating specific ECM components have not been determined. In striated muscle, the identity of these cells becomes important in disease when ECM changes result in fibrosis and subsequent increased tissue stiffness and dysfunction. Here we describe a novel approach to isolate and identify cells that maintain the ECM in both healthy and fibrotic muscle. Using a collagen I reporter mouse, we show that there are three distinct cell populations that express collagen I in both healthy and fibrotic skeletal muscle. Interestingly, the number of collagen I-expressing cells in all three cell populations increases proportionally in fibrotic muscle, indicating that all cell types participate in the fibrosis process. Furthermore, while some profibrotic ECM and ECM-associated genes are significantly upregulated in fibrotic muscle, the fibrillar collagen gene expression profile is not qualitatively altered. This suggests that muscle fibrosis in this model results from an increased number of collagen I-expressing cells and not the initiation of a specific fibrotic collagen gene expression program. Finally, in fibrotic muscle, we show that these collagen I-expressing cell populations differentially express distinct ECM proteins—fibroblasts express the fibrillar components of ECM, fibro/adipogenic progenitors cells differentially express basal laminar proteins, and skeletal muscle progenitor cells differentially express genes important for the satellite cell. PMID:27881411

Novel application of multi-stimuli network inference to synovial fibroblasts of rheumatoid arthritis patients

PubMed Central

2014-01-01

Background Network inference of gene expression data is an important challenge in systems biology. Novel algorithms may provide more detailed gene regulatory networks (GRN) for complex, chronic inflammatory diseases such as rheumatoid arthritis (RA), in which activated synovial fibroblasts (SFBs) play a major role. Since the detailed mechanisms underlying this activation are still unclear, simultaneous investigation of multi-stimuli activation of SFBs offers the possibility to elucidate the regulatory effects of multiple mediators and to gain new insights into disease pathogenesis. Methods A GRN was therefore inferred from RA-SFBs treated with 4 different stimuli (IL-1 β, TNF- α, TGF- β, and PDGF-D). Data from time series microarray experiments (0, 1, 2, 4, 12 h; Affymetrix HG-U133 Plus 2.0) were batch-corrected applying ‘ComBat’, analyzed for differentially expressed genes over time with ‘Limma’, and used for the inference of a robust GRN with NetGenerator V2.0, a heuristic ordinary differential equation-based method with soft integration of prior knowledge. Results Using all genes differentially expressed over time in RA-SFBs for any stimulus, and selecting the genes belonging to the most significant gene ontology (GO) term, i.e., ‘cartilage development’, a dynamic, robust, moderately complex multi-stimuli GRN was generated with 24 genes and 57 edges in total, 31 of which were gene-to-gene edges. Prior literature-based knowledge derived from Pathway Studio or manual searches was reflected in the final network by 25/57 confirmed edges (44%). The model contained known network motifs crucial for dynamic cellular behavior, e.g., cross-talk among pathways, positive feed-back loops, and positive feed-forward motifs (including suppression of the transcriptional repressor OSR2 by all 4 stimuli. Conclusion A multi-stimuli GRN highly concordant with literature data was successfully generated by network inference from the gene expression of stimulated RA-SFBs. The GRN showed high reliability, since 10 predicted edges were independently validated by literature findings post network inference. The selected GO term ‘cartilage development’ contained a number of differentiation markers, growth factors, and transcription factors with potential relevance for RA. Finally, the model provided new insight into the response of RA-SFBs to multiple stimuli implicated in the pathogenesis of RA, in particular to the ‘novel’ potent growth factor PDGF-D. PMID:24989895

The Drosophila Translational Control Element (TCE) Is Required for High-Level Transcription of Many Genes That Are Specifically Expressed in Testes

PubMed Central

Anderson, Ashley K.; Ohler, Uwe; Wassarman, David A.

2012-01-01

To investigate the importance of core promoter elements for tissue-specific transcription of RNA polymerase II genes, we examined testis-specific transcription in Drosophila melanogaster. Bioinformatic analyses of core promoter sequences from 190 genes that are specifically expressed in testes identified a 10 bp A/T-rich motif that is identical to the translational control element (TCE). The TCE functions in the 5′ untranslated region of Mst(3)CGP mRNAs to repress translation, and it also functions in a heterologous gene to regulate transcription. We found that among genes with focused initiation patterns, the TCE is significantly enriched in core promoters of genes that are specifically expressed in testes but not in core promoters of genes that are specifically expressed in other tissues. The TCE is variably located in core promoters and is conserved in melanogaster subgroup species, but conservation dramatically drops in more distant species. In transgenic flies, short (300–400 bp) genomic regions containing a TCE directed testis-specific transcription of a reporter gene. Mutation of the TCE significantly reduced but did not abolish reporter gene transcription indicating that the TCE is important but not essential for transcription activation. Finally, mutation of testis-specific TFIID (tTFIID) subunits significantly reduced the transcription of a subset of endogenous TCE-containing but not TCE-lacking genes, suggesting that tTFIID activity is limited to TCE-containing genes but that tTFIID is not an obligatory regulator of TCE-containing genes. Thus, the TCE is a core promoter element in a subset of genes that are specifically expressed in testes. Furthermore, the TCE regulates transcription in the context of short genomic regions, from variable locations in the core promoter, and both dependently and independently of tTFIID. These findings set the stage for determining the mechanism by which the TCE regulates testis-specific transcription and understanding the dual role of the TCE in translational and transcriptional regulation. PMID:22984601

The Drosophila Translational Control Element (TCE) is required for high-level transcription of many genes that are specifically expressed in testes.

PubMed

Katzenberger, Rebeccah J; Rach, Elizabeth A; Anderson, Ashley K; Ohler, Uwe; Wassarman, David A

2012-01-01

To investigate the importance of core promoter elements for tissue-specific transcription of RNA polymerase II genes, we examined testis-specific transcription in Drosophila melanogaster. Bioinformatic analyses of core promoter sequences from 190 genes that are specifically expressed in testes identified a 10 bp A/T-rich motif that is identical to the translational control element (TCE). The TCE functions in the 5' untranslated region of Mst(3)CGP mRNAs to repress translation, and it also functions in a heterologous gene to regulate transcription. We found that among genes with focused initiation patterns, the TCE is significantly enriched in core promoters of genes that are specifically expressed in testes but not in core promoters of genes that are specifically expressed in other tissues. The TCE is variably located in core promoters and is conserved in melanogaster subgroup species, but conservation dramatically drops in more distant species. In transgenic flies, short (300-400 bp) genomic regions containing a TCE directed testis-specific transcription of a reporter gene. Mutation of the TCE significantly reduced but did not abolish reporter gene transcription indicating that the TCE is important but not essential for transcription activation. Finally, mutation of testis-specific TFIID (tTFIID) subunits significantly reduced the transcription of a subset of endogenous TCE-containing but not TCE-lacking genes, suggesting that tTFIID activity is limited to TCE-containing genes but that tTFIID is not an obligatory regulator of TCE-containing genes. Thus, the TCE is a core promoter element in a subset of genes that are specifically expressed in testes. Furthermore, the TCE regulates transcription in the context of short genomic regions, from variable locations in the core promoter, and both dependently and independently of tTFIID. These findings set the stage for determining the mechanism by which the TCE regulates testis-specific transcription and understanding the dual role of the TCE in translational and transcriptional regulation.

Immunological aspects in chronic lymphocytic leukemia (CLL) development.

PubMed

García-Muñoz, Ricardo; Galiacho, Verónica Roldan; Llorente, Luis

2012-07-01

Chronic lymphocytic leukemia (CLL) is unique among B cell malignancies in that the malignant clones can be featured either somatically mutated or unmutated IGVH genes. CLL cells that express unmutated immunoglobulin variable domains likely underwent final development prior to their entry into the germinal center, whereas those that express mutated variable domains likely transited through the germinal center and then underwent final development. Regardless, the cellular origin of CLL remains unknown. The aim of this review is to summarize immunological aspects involved in this process and to provide insights about the complex biology and pathogenesis of this disease. We propose a mechanistic hypothesis to explain the origin of B-CLL clones into our current picture of normal B cell development. In particular, we suggest that unmutated CLL arises from normal B cells with self-reactivity for apoptotic bodies that have undergone receptor editing, CD5 expression, and anergic processes in the bone marrow. Similarly, mutated CLL would arise from cells that, while acquiring self-reactivity for autoantigens-including apoptotic bodies-in germinal centers, are also still subject to tolerization mechanisms, including receptor editing and anergy. We believe that CLL is a proliferation of B lymphocytes selected during clonal expansion through multiple encounters with (auto)antigens, despite the fact that they differ in their state of activation and maturation. Autoantigens and microbial pathogens activate BCR signaling and promote tolerogenic mechanisms such as receptor editing/revision, anergy, CD5+ expression, and somatic hypermutation in CLL B cells. The result of these tolerogenic mechanisms is the survival of CLL B cell clones with similar surface markers and homogeneous gene expression signatures. We suggest that both immunophenotypic surface markers and homogenous gene expression might represent the evidence of several attempts to re-educate self-reactive B cells.

Vascular gene expression: a hypothesis

PubMed Central

Martínez-Navarro, Angélica C.; Galván-Gordillo, Santiago V.; Xoconostle-Cázares, Beatriz; Ruiz-Medrano, Roberto

2013-01-01

The phloem is the conduit through which photoassimilates are distributed from autotrophic to heterotrophic tissues and is involved in the distribution of signaling molecules that coordinate plant growth and responses to the environment. Phloem function depends on the coordinate expression of a large array of genes. We have previously identified conserved motifs in upstream regions of the Arabidopsis genes, encoding the homologs of pumpkin phloem sap mRNAs, displaying expression in vascular tissues. This tissue-specific expression in Arabidopsis is predicted by the overrepresentation of GA/CT-rich motifs in gene promoters. In this work we have searched for common motifs in upstream regions of the homologous genes from plants considered to possess a “primitive” vascular tissue (a lycophyte), as well as from others that lack a true vascular tissue (a bryophyte), and finally from chlorophytes. Both lycophyte and bryophyte display motifs similar to those found in Arabidopsis with a significantly low E-value, while the chlorophytes showed either a different conserved motif or no conserved motif at all. These results suggest that these same genes are expressed coordinately in non-vascular plants; this coordinate expression may have been one of the prerequisites for the development of conducting tissues in plants. We have also analyzed the phylogeny of conserved proteins that may be involved in phloem function and development. The presence of CmPP16, APL, FT, and YDA in chlorophytes suggests the recruitment of ancient regulatory networks for the development of the vascular tissue during evolution while OPS is a novel protein specific to vascular plants. PMID:23882276

The Metastasis Efficiency Modifier Ribosomal RNA Processing 1 Homolog B (RRP1B) Is a Chromatin-associated Factor*

PubMed Central

Crawford, Nigel P. S.; Yang, Hailiu; Mattaini, Katherine R.; Hunter, Kent W.

2009-01-01

There is accumulating evidence for a role of germ line variation in breast cancer metastasis. We have recently identified a novel metastasis susceptibility gene, Rrp1b (ribosomal RNA processing 1 homolog B). Overexpression of Rrp1b in a mouse mammary tumor cell line induces a gene expression signature that predicts survival in breast cancer. Here we extend the analysis of RRP1B function by demonstrating that the Rrp1b activation gene expression signature accurately predicted the outcome in three of four publicly available breast carcinoma gene expression data sets. In addition, we provide insights into the mechanism of RRP1B. Tandem affinity purification demonstrated that RRP1B physically interacts with many nucleosome binding factors, including histone H1X, poly(ADP-ribose) polymerase 1, TRIM28 (tripartite motif-containing 28), and CSDA (cold shock domain protein A). Co-immunofluorescence and co-immunoprecipitation confirmed these interactions and also interactions with heterochromatin protein-1α and acetyl-histone H4 lysine 5. Finally, we investigated the effects of ectopic expression of an RRP1B allelic variant previously associated with improved survival in breast cancer. Gene expression analyses demonstrate that, compared with ectopic expression of wild type RRP1B in HeLa cells, the variant RRP1B differentially modulates various transcription factors controlled by TRIM28 and CSDA. These data suggest that RRP1B, a tumor progression and metastasis susceptibility candidate gene, is potentially a dynamic modulator of transcription and chromatin structure. PMID:19710015

Liver Cell-Derived Microparticles Activate Hedgehog Signaling and Alter Gene Expression in Hepatic Endothelial Cells

PubMed Central

Witek, Rafal P.; Yang, Liu; Liu, Renshui; Jung, Youngmi; Omenetti, Alessia; Syn, Wing-Kin; Choi, Steve S.; Cheong, Yeiwon; Fearing, Caitlin M.; Agboola, Kolade M.; Chen, Wei; Diehl, Anna Mae

2013-01-01

Background & Aims Angiogenesis contributes to vascular remodeling during cirrhosis. In cirrhotic livers, cholangiocytes and myofibroblastic hepatic stellate cells (MF-HSC) produce Hedgehog (Hh) ligands. During embryogenesis Hh ligands are released from ligand-producing cells in microparticles and activate Hh signaling in endothelial cells. We studied whether adult liver cell-derived microparticles contain Hh ligands that alter hepatic sinusoidal endothelial cells (SEC). Methods MF-HSCs and cholangiocytes were exposed to platelet-derived growth factor (PDGF) to induce Hh ligands; microparticles were isolated from medium, analyzed by transmission electron microscopy (TEM) and immunoblots, and applied to Hh-reporter containing cells. Microparticles were also obtained from serum and bile of rats after bile duct ligation (BDL) or sham surgery and applied to normal primary liver SEC with or without cyclopamine, a Hh signaling inhibitor. Effects on SEC gene expression were evaluated by QRT-PCR and immunoblotting. Finally, Hh target gene expression and SEC activation markers were compared in primary SEC and in liver sections from healthy and BDL rats. Results PDGF-treated MF-HSC and cholangiocytes released exosome-enriched microparticles containing biologically active Hh ligands. BDL also increased release of Hh-containing exosome-enriched microparticles into plasma and bile. TEM and immunoblots revealed similarities among microparticles from all sources; all microparticles induced similar Hh-dependent changes in SEC gene expression. SEC from healthy livers did not express Hh target genes or activation markers, but both were up-regulated in SEC after BDL. Conclusions Hh-containing exosome-enriched microparticles released from liver cells alter hepatic SEC gene expression, suggesting a novel mechanism for cirrhotic vasculopathy. PMID:19013163

Puromycin and Methotrexate Resistance Cassettes and Optimized cre-recombinase Expression Plasmids for use in Yeast

PubMed Central

MacDonald, Chris; Piper, Robert C.

2015-01-01

Here we expand the set of tools for genetically manipulating Saccharomyces cerevisiae. We show that puromycin-resistance can be achieved in yeast through expression of a bacterial puromycin-resistance gene optimized to the yeast codon bias, which in turn serves as an easy to use dominant genetic marker suitable for gene disruption. We have constructed a similar DNA cassette expressing yeast codon-optimized mutant human dihydrofolate reductase (DHFR) that confers resistance to methotrexate and can also be used as a dominant selectable marker. Both of these drug-resistant marker cassettes are flanked by loxP sites allowing for their excision from the genome following expression of cre-recombinase. Finally, we have created a series of plasmids for low-level constitutive expression of cre-recombinase in yeast that allows for efficient excision of loxP-flanked markers. PMID:25688547

Heat Stable Enzymes from Thermophiles

DTIC Science & Technology

1998-02-01

final product and is somewhat messy to work with. Therefore, alternatives were tested. However, no combination of corn syrup , alternative sugars and...INTRODUCTION 9 CLONING OF ALKALINE PHOSPHATASE GENE AND PRODUCTION OF HIGH SPECIFIC ACTIVITY ENZYME 9 Cloning into E. coil and expression of high activity...JKR209, into an alternative, better producing organism. CLONING OF ALKALINE PHOSPHATASE GENE AND PRODUCTION OF HIGH SPECIFIC ACTIVITY ENZYME Cloning into

Genetic Contributions of Inflammation to Depression

PubMed Central

Barnes, Jacob; Mondelli, Valeria; Pariante, Carmine M

2017-01-01

This paper describes the effects of immune genes genetic variants and mRNA expression on depression's risk, severity, and response to antidepressant treatment, through a systematic review on all papers published between 2000 and 2016. Our results, based largely on case–control studies, suggest that common genetic variants and gene-expression pathways are involved in both immune activation and depression. The most replicated and relevant genetic variants include polymorphisms in the genes for interleukin (IL)-1β, IL-6, IL-10, monocyte chemoattractant protein-1, tumor necrosis factor-alpha, C-reactive protein, and phospholipase A2. Moreover, increased blood cytokines mRNA expression (especially of IL-1β) identifies patients that are less likely to respond to conventional antidepressants. However, even for the most replicated findings there are inconsistent results, not only between studies, but also between the immune effects of the genetic variants and the resulting effects on depression. We find evidence that these discrepant findings may be explained, at least in part, by the heterogeneity of the depression immunophenotype, by environmental influences and gene × environment interactions, and by the complex interfacing of genetic variants with gene expression. Indeed, some of the most robust findings have been obtained in patients developing depression in the context of treatment with interferon-alpha, a widely used model to mimic depression in the context of inflammation. Further ‘omics' approaches, through GWAS and transcriptomics, will finally shed light on the interaction between immune genes, their expression, and the influence of the environment, in the pathogenesis of depression. PMID:27555379

Robust transcriptional tumor signatures applicable to both formalin-fixed paraffin-embedded and fresh-frozen samples

PubMed Central

Cheng, Jun; He, Jun; Liu, Huaping; Cai, Hao; Hong, Guini; Zhang, Jiahui; Li, Na; Ao, Lu; Guo, Zheng

2017-01-01

Formalin-fixed paraffin-embedded (FFPE) samples represent a valuable resource for clinical researches. However, FFPE samples are usually considered an unreliable source for gene expression analysis due to the partial RNA degradation. In this study, through comparing gene expression profiles between FFPE samples and paired fresh-frozen (FF) samples for three cancer types, we firstly showed that expression measurements of thousands of genes had at least two-fold change in FFPE samples compared with paired FF samples. Therefore, for a transcriptional signature based on risk scores summarized from the expression levels of the signature genes, the risk score thresholds trained from FFPE (or FF) samples could not be applied to FF (or FFPE) samples. On the other hand, we found that more than 90% of the relative expression orderings (REOs) of gene pairs in the FF samples were maintained in their paired FFPE samples and largely unaffected by the storage time. The result suggested that the REOs of gene pairs were highly robust against partial RNA degradation in FFPE samples. Finally, as a case study, we developed a REOs-based signature to distinguish liver cirrhosis from hepatocellular carcinoma (HCC) using FFPE samples. The signature was validated in four datasets of FFPE samples and eight datasets of FF samples. In conclusion, the valuable FFPE samples can be fully exploited to identify REOs-based diagnostic and prognostic signatures which could be robustly applicable to both FF samples and FFPE samples with degraded RNA. PMID:28036264

RNA Seq analysis for transcriptome profiling in response to classical swine fever vaccination in indigenous and crossbred pigs.

PubMed

Pathak, Shalu Kumari; Kumar, Amit; Bhuwana, G; Sah, Vaishali; Upmanyu, Vikramadiya; Tiwari, A K; Sahoo, A P; Sahoo, A R; Wani, Sajjad A; Panigrahi, Manjit; Sahoo, N R; Kumar, Ravi

2017-09-01

In present investigation, differential expression of transcriptome after classical swine fever (CSF) vaccination has been explored at the cellular level in crossbred and indigenous (desi) piglets. RNA Sequencing by Expectation-Maximization (RSEM) package was used to quantify gene expression from RNA Sequencing data, and differentially expressed genes (DEGs) were identified using EBSeq, DESeq2, and edgeR softwares. After analysis, 5222, 6037, and 6210 common DEGs were identified in indigenous post-vaccinated verses pre-vaccinated, crossbred post-vaccinated verses pre-vaccinated, and post-vaccinated crossbred verses indigenous pigs, respectively. Functional annotation of these DEGs showed enrichment of antigen processing-cross presentation, B cell receptor signaling, T cell receptor signaling, NF-κB signaling, and TNF signaling pathways. The interaction network among the immune genes included more number of genes with greater connectivity in vaccinated crossbred than the indigenous piglets. Higher expression of IRF3, IL1β, TAP1, CSK, SLA2, SLADM, and NF-kB in crossbred piglets in comparison to indigenous explains the better humoral response observed in crossbred piglets. Here, we predicted that the processed CSFV antigen through the T cell receptor signaling cascade triggers the B cell receptor-signaling pathway to finally activate MAPK kinase and NF-κB signaling pathways in B cell. This activation results in expression of genes/transcription factors that lead to B cell ontogeny, auto immunity and immune response through antibody production. Further, immunologically important genes were validated by qRT-PCR.

Development of a Novel Targeted RNAi Delivery Technology inTherapies for Metabolic Diseases

DTIC Science & Technology

2017-10-01

resulting in the disease state denoted NASH, is often associated with obesity and type 2 diabetes, which have increased in incidence to nearly 10% of the...liver in obesity . Our approach is to use powerful siRNA-mediated gene silencing to decrease the expression of one or more genes that advance this...proposed that this final key goal of silencing one or more genes to alleviate hepatosteatosis in mouse models of obesity would be accomplished over

Comprehensive Analysis of Gene Expression Profiles of Sepsis-Induced Multiorgan Failure Identified Its Valuable Biomarkers.

PubMed

Wang, Yumei; Yin, Xiaoling; Yang, Fang

2018-02-01

Sepsis is an inflammatory-related disease, and severe sepsis would induce multiorgan dysfunction, which is the most common cause of death of patients in noncoronary intensive care units. Progression of novel therapeutic strategies has proven to be of little impact on the mortality of severe sepsis, and unfortunately, its mechanisms still remain poorly understood. In this study, we analyzed gene expression profiles of severe sepsis with failure of lung, kidney, and liver for the identification of potential biomarkers. We first downloaded the gene expression profiles from the Gene Expression Omnibus and performed preprocessing of raw microarray data sets and identification of differential expression genes (DEGs) through the R programming software; then, significantly enriched functions of DEGs in lung, kidney, and liver failure sepsis samples were obtained from the Database for Annotation, Visualization, and Integrated Discovery; finally, protein-protein interaction network was constructed for DEGs based on the STRING database, and network modules were also obtained through the MCODE cluster method. As a result, lung failure sepsis has the highest number of DEGs of 859, whereas the number of DEGs in kidney and liver failure sepsis samples is 178 and 175, respectively. In addition, 17 overlaps were obtained among the three lists of DEGs. Biological processes related to immune and inflammatory response were found to be significantly enriched in DEGs. Network and module analysis identified four gene clusters in which all or most of genes were upregulated. The expression changes of Icam1 and Socs3 were further validated through quantitative PCR analysis. This study should shed light on the development of sepsis and provide potential therapeutic targets for sepsis-induced multiorgan failure.

From single-cell to cell-pool transcriptomes: stochasticity in gene expression and RNA splicing.

PubMed

Marinov, Georgi K; Williams, Brian A; McCue, Ken; Schroth, Gary P; Gertz, Jason; Myers, Richard M; Wold, Barbara J

2014-03-01

Single-cell RNA-seq mammalian transcriptome studies are at an early stage in uncovering cell-to-cell variation in gene expression, transcript processing and editing, and regulatory module activity. Despite great progress recently, substantial challenges remain, including discriminating biological variation from technical noise. Here we apply the SMART-seq single-cell RNA-seq protocol to study the reference lymphoblastoid cell line GM12878. By using spike-in quantification standards, we estimate the absolute number of RNA molecules per cell for each gene and find significant variation in total mRNA content: between 50,000 and 300,000 transcripts per cell. We directly measure technical stochasticity by a pool/split design and find that there are significant differences in expression between individual cells, over and above technical variation. Specific gene coexpression modules were preferentially expressed in subsets of individual cells, including one enriched for mRNA processing and splicing factors. We assess cell-to-cell variation in alternative splicing and allelic bias and report evidence of significant differences in splice site usage that exceed splice variation in the pool/split comparison. Finally, we show that transcriptomes from small pools of 30-100 cells approach the information content and reproducibility of contemporary RNA-seq from large amounts of input material. Together, our results define an experimental and computational path forward for analyzing gene expression in rare cell types and cell states.

Photoperiodic regulation of glycogen metabolism, glycolysis, and glutamine synthesis in tanycytes of the Siberian hamster suggests novel roles of tanycytes in hypothalamic function.

PubMed

Nilaweera, Kanishka; Herwig, Annika; Bolborea, Matei; Campbell, Gill; Mayer, Claus D; Morgan, Peter J; Ebling, Francis J P; Barrett, Perry

2011-11-01

The objective of this study is to investigate the impact of photoperiod on the temporal and spatial expression of genes involved in glucose metabolism in the brain of the seasonal mammal Phodopus sungorus (Siberian hamster). In situ hybridization was performed on brain sections obtained from male hamsters held in long photoperiod (high body weight and developed testes) or short photoperiod (reduced body weight with testicular regression). This analysis revealed upregulation in expression of genes involved in glycogen and glucose metabolism in short photoperiod and localized to the tanycyte layer of the third ventricle. On the basis of these data and a previously identified photoperiod-dependent increase in activity of neighboring hypothalamic neurons, we hypothesized that the observed expression changes may reflect alteration in either metabolic fuel or precursor neurotransmitter supply to surrounding neurons. Gene expression analysis was performed for genes involved in lactate and glutamate transport. This analysis showed that the gene for the lactate transporter MCT2 and glutamate transporter GLAST was decreased in the tanycyte layer in short photoperiod. Expression of mRNA for glutamine synthetase, the final enzyme in the synthesis of the neuronal neurotransmitter precursor, glutamine, was also decreased in short photoperiod. These data suggest a role for tanycytes in modulating glutamate concentrations and neurotransmitter supply in the hypothalamic environment. Copyright © 2011 Wiley-Liss, Inc.

Anther-preferential expressing gene PMR is essential for the mitosis of pollen development in rice.

PubMed

Liu, Yaqin; Xu, Ya; Ling, Sheng; Liu, Shasha; Yao, Jialing

2017-06-01

Phenotype identification, expression examination, and function prediction declared that the anther-preferential expressing gene PMR may participate in regulation of male gametophyte development in rice. Male germline development in flowering plants produces the pair of sperm cells for double fertilization and the pollen mitosis is a key process of it. Although the structural features of male gametophyte have been defined, the molecular mechanisms regulating the mitotic cell cycle are not well elucidated in rice. Here, we reported an anther-preferential expressing gene in rice, PMR (Pollen Mitosis Relative), playing an essential role in male gametogenesis. When PMR gene was suppressed via RNAi, the mitosis of microspore was severely damaged, and the plants formed unmatured pollens containing only one or two nucleuses at the anthesis, ultimately leading to serious reduction of pollen fertility and seed-setting. The CRISPR mutants, pmr-1 and pmr-2, both showed the similar defects as the PMR-RNAi lines. Further analysis revealed that PMR together with its co-expressing genes were liable to participate in the regulation of DNA metabolism in the nucleus, and affected the activities of some enzymes related to the cell cycle. We finally discussed that unknown protein PMR contained the PHD, SWIB and Plus-3 domains and they might have coordinating functions in regulation pathway of the pollen mitosis in rice.

Transcriptional Analysis of Drought-Induced Genes in the Roots of a Tolerant Genotype of the Common Bean (Phaseolus vulgaris L.)

PubMed Central

Recchia, Gustavo Henrique; Caldas, Danielle Gregorio Gomes; Beraldo, Ana Luiza Ahern; da Silva, Márcio José; Tsai, Siu Mui

2013-01-01

In Brazil, common bean (Phaseolus vulgaris L.) productivity is severely affected by drought stress due to low technology cultivation systems. Our purpose was to identify differentially expressed genes in roots of a genotype tolerant to water deficit (BAT 477) when submitted to an interruption of irrigation during its development. A SSH library was constructed taking as “driver” the genotype Carioca 80SH (susceptible to drought). After clustering and data mining, 1572 valid reads were obtained, resulting in 1120 ESTs (expressed sequence tags). We found sequences for transcription factors, carbohydrates metabolism, proline-rich proteins, aquaporins, chaperones and ubiquitins, all of them organized according to their biological processes. Our suppressive subtractive hybridization (SSH) library was validated through RT-qPCR experiment by assessing the expression patterns of 10 selected genes in both genotypes under stressed and control conditions. Finally, the expression patterns of 31 ESTs, putatively related to drought responses, were analyzed in a time-course experiment. Our results confirmed that such genes are more expressed in the tolerant genotype during stress; however, they are not exclusive, since different levels of these transcripts were also detected in the susceptible genotype. In addition, we observed a fluctuation in gene regulation over time for both the genotypes, which seem to adopt and adapt different strategies in order to develop tolerance against this stress. PMID:23538843

Inferring gene expression from ribosomal promoter sequences, a crowdsourcing approach

PubMed Central

Meyer, Pablo; Siwo, Geoffrey; Zeevi, Danny; Sharon, Eilon; Norel, Raquel; Segal, Eran; Stolovitzky, Gustavo; Siwo, Geoffrey; Rider, Andrew K.; Tan, Asako; Pinapati, Richard S.; Emrich, Scott; Chawla, Nitesh; Ferdig, Michael T.; Tung, Yi-An; Chen, Yong-Syuan; Chen, Mei-Ju May; Chen, Chien-Yu; Knight, Jason M.; Sahraeian, Sayed Mohammad Ebrahim; Esfahani, Mohammad Shahrokh; Dreos, Rene; Bucher, Philipp; Maier, Ezekiel; Saeys, Yvan; Szczurek, Ewa; Myšičková, Alena; Vingron, Martin; Klein, Holger; Kiełbasa, Szymon M.; Knisley, Jeff; Bonnell, Jeff; Knisley, Debra; Kursa, Miron B.; Rudnicki, Witold R.; Bhattacharjee, Madhuchhanda; Sillanpää, Mikko J.; Yeung, James; Meysman, Pieter; Rodríguez, Aminael Sánchez; Engelen, Kristof; Marchal, Kathleen; Huang, Yezhou; Mordelet, Fantine; Hartemink, Alexander; Pinello, Luca; Yuan, Guo-Cheng

2013-01-01

The Gene Promoter Expression Prediction challenge consisted of predicting gene expression from promoter sequences in a previously unknown experimentally generated data set. The challenge was presented to the community in the framework of the sixth Dialogue for Reverse Engineering Assessments and Methods (DREAM6), a community effort to evaluate the status of systems biology modeling methodologies. Nucleotide-specific promoter activity was obtained by measuring fluorescence from promoter sequences fused upstream of a gene for yellow fluorescence protein and inserted in the same genomic site of yeast Saccharomyces cerevisiae. Twenty-one teams submitted results predicting the expression levels of 53 different promoters from yeast ribosomal protein genes. Analysis of participant predictions shows that accurate values for low-expressed and mutated promoters were difficult to obtain, although in the latter case, only when the mutation induced a large change in promoter activity compared to the wild-type sequence. As in previous DREAM challenges, we found that aggregation of participant predictions provided robust results, but did not fare better than the three best algorithms. Finally, this study not only provides a benchmark for the assessment of methods predicting activity of a specific set of promoters from their sequence, but it also shows that the top performing algorithm, which used machine-learning approaches, can be improved by the addition of biological features such as transcription factor binding sites. PMID:23950146

Development of siRNA expression vector utilizing rock bream beta-actin promoter: a potential therapeutic tool against viral infection in fish.

PubMed

Zenke, Kosuke; Nam, Yoon Kwon; Kim, Ki Hong

2010-01-01

In the present study, we have developed short interfering RNA (siRNA) expression vector utilizing rock bream beta-actin promoter and examined the possible use for the inhibition of highly pathogenic fish virus, rock bream iridovirus (RBIV), replication in vitro. Initially, in order to express siRNA effectively, we added several modifications to wild-type rock bream beta-actin promoter. Next, we succeeded in knocking down the expression of enhanced green fluorescent protein reporter gene expression in fish cells using newly developed vector more effectively than the fugu U6 promoter-driven vector we described previously. Finally, we could observe that cells transfected with modified rock bream beta-actin promoter-driven siRNA expression vector targeting major capsid protein (MCP) gene of RBIV exhibited more resistance to RBIV challenge than other control cells. Our results indicate that this novel siRNA expression vector can be used as a new tool for therapeutics in virus infection in fish species.

Lamin A/C Is Required for ChAT-Dependent Neuroblastoma Differentiation.

PubMed

Guglielmi, Loredana; Nardella, Marta; Musa, Carla; Iannetti, Ilaria; Arisi, Ivan; D'Onofrio, Mara; Storti, Andrea; Valentini, Alessandra; Cacci, Emanuele; Biagioni, Stefano; Augusti-Tocco, Gabriella; D'Agnano, Igea; Felsani, Armando

2017-07-01

The mouse neuroblastoma N18TG2 clone is unable to differentiate and is defective for the enzymes of the biosynthesis of neurotransmitters. The forced expression of choline acetyltransferase (ChAT) in these cells results in the synthesis and release of acetylcholine (Ach) and hence in the expression of neurospecific features and markers. To understand how the expression of ChAT triggered neuronal differentiation, we studied the differences in genome-wide transcription profiles between the N18TG2 parental cells and its ChAT-expressing 2/4 derived clone. The engagement of the 2/4 cells in the neuronal developmental program was confirmed by the increase of the expression level of several differentiation-related genes and by the reduction of the amount of transcripts of cell cycle genes. At the same time, we observed a massive reorganization of cytoskeletal proteins in terms of gene expression, with the accumulation of the nucleoskeletal lamina component Lamin A/C in differentiating cells. The increase of the Lmna transcripts induced by ChAT expression in 2/4 cells was mimicked treating the parental N18TG2 cells with the acetylcholine receptor agonist carbachol, thus demonstrating the direct role played by this receptor in neuron nuclei maturation. Conversely, a treatment of 2/4 cells with the muscarinic receptor antagonist atropine resulted in the reduction of the amount of Lmna RNA. Finally, the hypothesis that Lmna gene product might play a crucial role in the ChAT-dependent molecular differentiation cascade was strongly supported by Lmna knockdown in 2/4 cells leading to the downregulation of genes involved in differentiation and cytoskeleton formation and to the upregulation of genes known to regulate self-renewal and stemness.

Revealing cell cycle control by combining model-based detection of periodic expression with novel cis-regulatory descriptors

PubMed Central

Andersson, Claes R; Hvidsten, Torgeir R; Isaksson, Anders; Gustafsson, Mats G; Komorowski, Jan

2007-01-01

Background We address the issue of explaining the presence or absence of phase-specific transcription in budding yeast cultures under different conditions. To this end we use a model-based detector of gene expression periodicity to divide genes into classes depending on their behavior in experiments using different synchronization methods. While computational inference of gene regulatory circuits typically relies on expression similarity (clustering) in order to find classes of potentially co-regulated genes, this method instead takes advantage of known time profile signatures related to the studied process. Results We explain the regulatory mechanisms of the inferred periodic classes with cis-regulatory descriptors that combine upstream sequence motifs with experimentally determined binding of transcription factors. By systematic statistical analysis we show that periodic classes are best explained by combinations of descriptors rather than single descriptors, and that different combinations correspond to periodic expression in different classes. We also find evidence for additive regulation in that the combinations of cis-regulatory descriptors associated with genes periodically expressed in fewer conditions are frequently subsets of combinations associated with genes periodically expression in more conditions. Finally, we demonstrate that our approach retrieves combinations that are more specific towards known cell-cycle related regulators than the frequently used clustering approach. Conclusion The results illustrate how a model-based approach to expression analysis may be particularly well suited to detect biologically relevant mechanisms. Our new approach makes it possible to provide more refined hypotheses about regulatory mechanisms of the cell cycle and it can easily be adjusted to reveal regulation of other, non-periodic, cellular processes. PMID:17939860

Co-expression networks reveal the tissue-specific regulation of transcription and splicing

PubMed Central

Saha, Ashis; Kim, Yungil; Gewirtz, Ariel D.H.; Jo, Brian; Gao, Chuan; McDowell, Ian C.; Engelhardt, Barbara E.

2017-01-01

Gene co-expression networks capture biologically important patterns in gene expression data, enabling functional analyses of genes, discovery of biomarkers, and interpretation of genetic variants. Most network analyses to date have been limited to assessing correlation between total gene expression levels in a single tissue or small sets of tissues. Here, we built networks that additionally capture the regulation of relative isoform abundance and splicing, along with tissue-specific connections unique to each of a diverse set of tissues. We used the Genotype-Tissue Expression (GTEx) project v6 RNA sequencing data across 50 tissues and 449 individuals. First, we developed a framework called Transcriptome-Wide Networks (TWNs) for combining total expression and relative isoform levels into a single sparse network, capturing the interplay between the regulation of splicing and transcription. We built TWNs for 16 tissues and found that hubs in these networks were strongly enriched for splicing and RNA binding genes, demonstrating their utility in unraveling regulation of splicing in the human transcriptome. Next, we used a Bayesian biclustering model that identifies network edges unique to a single tissue to reconstruct Tissue-Specific Networks (TSNs) for 26 distinct tissues and 10 groups of related tissues. Finally, we found genetic variants associated with pairs of adjacent nodes in our networks, supporting the estimated network structures and identifying 20 genetic variants with distant regulatory impact on transcription and splicing. Our networks provide an improved understanding of the complex relationships of the human transcriptome across tissues. PMID:29021288

The nature of electron acceptor (MnIV/NO3) triggers differential expression of genes associated with stress and ammonium limitation responses in Shewanella algae C6G3.

PubMed

Aigle, Axel; Bonin, Patricia; -Nunez, Nicolas Fernandez; Loriod, Béatrice; Guasco, Sophie; Bergon, Aurélie; Armougom, Fabrice; Iobbi-Nivol, Chantal; Imbert, Jean; Michotey, Valérie

2018-03-16

Shewanella algae C6G3 can reduce dissimilatively nitrate into ammonium and manganese-oxide (MnIV) into MnII. It has the unusual ability to produce anaerobically nitrite from ammonium in the presence of MnIV. To gain insight into their metabolic capabilities, global mRNA expression patterns were investigated by RNA-seq and qRT-PCR in cells growing with lactate and ammonium as carbon and nitrogen sources and with either MnIV or nitrate as electron acceptors. Gene exhibiting higher expression levels in the presence of MnIV belonged to functional categories of carbohydrate, coenzyme, lipid metabolisms and inorganic ion transport. Comparative transcriptomic pattern between MnIV and NO3 revealed that the strain presented an ammonium limitation status with MnIV, despite the presence of non-limiting concentration of ammonium under both culture conditions. In addition, in presence of MnIV, ntrB/nrtC regulators, ammonium channel, nitrogen regulatory protein P-II, glutamine synthetase and asparagine synthetase glutamine dependent genes were over-represented. Under nitrate condition, the expression of genes involved in the synthesis of several amino acids was increased. Finally, expression level of genes associated with the general stress response was also amplified and among them, katE, a putative catalase/peroxidase present on several Shewanella genomes, was highly expressed with a relative median value higher in MnIV condition.

Left-right axis asymmetry determining human Cryptic gene is transcriptionally repressed by Snail.

PubMed

Gupta, Kartik; Pilli, Vijaya Satish Sekhar; Aradhyam, Gopala Krishna

2016-10-28

Establishment of the left-right axis is important for positioning organs asymmetrically in the developing vertebrate-embryo. A number of factors like maternally deposited molecules have emerged essential in initiating the specification of the axis; the downstream events, however, are regulated by signal-transduction and gene-expression changes identifying which remains a crucial challenge. The EGF-CFC family member Cryptic, that functions as a co-receptor for some TGF-beta ligands, is developmentally expressed in higher mammals and mutations in the gene cause loss or change in left-right axis asymmetry. Despite the strong phenotype, no transcriptional-regulator of this gene is known till date. Using promoter-analyses tools, we found strong evidence that the developmentally essential transcription factor Snail binds to the human Cryptic-promoter. We cloned the promoter-region of human Cryptic in a reporter gene and observed decreased Cryptic-promoter activation upon increasing Snail expression. Further, the expression of Cryptic is down-regulated upon exogenous Snail expression, validating the reporter assays and the previously identified role of Snail as a transcriptional repressor. Finally, we demonstrate using gel-shift assay that Snail in nuclear extract of PANC1 cells interacts with the promoter-construct bearing putative Snail binding sites and confirm this finding using chromatin immunoprecipitation assay. Snail represses the expression of human Cryptic and therefore, might affect the signaling via Nodal that has previously been demonstrated to specify the left-right axis using the EGF-CFC co-receptors.

Helicobacter pylori CagA induces tumor suppressor gene hypermethylation by upregulating DNMT1 via AKT-NFκB pathway in gastric cancer development.

PubMed

Zhang, Bao-gui; Hu, Lei; Zang, Ming-de; Wang, He-xiao; Zhao, Wei; Li, Jian-fang; Su, Li-ping; Shao, Zhifeng; Zhao, Xiaodong; Zhu, Zheng-gang; Yan, Min; Liu, Bingya

2016-03-01

Methylation of CpG islands in tumor suppressor gene prompter is one of the most characteristic abnormalities in Helicobacter pylori (HP)-associated gastric carcinoma (GC). Here, we investigated the pathogenic and molecular mechanisms underlying hypermethylation of tumor suppressor genes in HP induced GC development. We found that tumor suppressor genes hypermethylation, represented by MGMT, positively correlated with CagA in clinical specimens, gastric tissues from HP infected C57 mice and GC cell lines transfected by CagA or treated by HP infection. CagA enhanced PDK1 and AKT interaction and increased AKT phosphorylation. The P-AKT subsequent activated NFκB, which then bound to DNMT1 promoter and increased its expression. Finally, the upregulated DNMT1 promoted tumor suppressor genes hypermethylation with MGMT as a representative. In conclusion, CagA increased tumor suppressor genes hypermethylation via stimulating DNMT1 expression through the AKT-NFκB pathway.

Helicobacter pylori CagA induces tumor suppressor gene hypermethylation by upregulating DNMT1 via AKT-NFκB pathway in gastric cancer development

PubMed Central

Wang, He-xiao; Zhao, Wei; Li, Jian-fang; Su, Li-ping; Shao, Zhifeng; Zhao, Xiaodong; Zhu, Zheng-gang; Yan, Min; Liu, Bingya

2016-01-01

Methylation of CpG islands in tumor suppressor gene prompter is one of the most characteristic abnormalities in Helicobacter pylori (HP)-associated gastric carcinoma (GC). Here, we investigated the pathogenic and molecular mechanisms underlying hypermethylation of tumor suppressor genes in HP induced GC development. We found that tumor suppressor genes hypermethylation, represented by MGMT, positively correlated with CagA in clinical specimens, gastric tissues from HP infected C57 mice and GC cell lines transfected by CagA or treated by HP infection. CagA enhanced PDK1 and AKT interaction and increased AKT phosphorylation. The P-AKT subsequent activated NFκB, which then bound to DNMT1 promoter and increased its expression. Finally, the upregulated DNMT1 promoted tumor suppressor genes hypermethylation with MGMT as a representative. In conclusion, CagA increased tumor suppressor genes hypermethylation via stimulating DNMT1 expression through the AKT-NFκB pathway. PMID:26848521

The Cross-Entropy Based Multi-Filter Ensemble Method for Gene Selection.

PubMed

Sun, Yingqiang; Lu, Chengbo; Li, Xiaobo

2018-05-17

The gene expression profile has the characteristics of a high dimension, low sample, and continuous type, and it is a great challenge to use gene expression profile data for the classification of tumor samples. This paper proposes a cross-entropy based multi-filter ensemble (CEMFE) method for microarray data classification. Firstly, multiple filters are used to select the microarray data in order to obtain a plurality of the pre-selected feature subsets with a different classification ability. The top N genes with the highest rank of each subset are integrated so as to form a new data set. Secondly, the cross-entropy algorithm is used to remove the redundant data in the data set. Finally, the wrapper method, which is based on forward feature selection, is used to select the best feature subset. The experimental results show that the proposed method is more efficient than other gene selection methods and that it can achieve a higher classification accuracy under fewer characteristic genes.

Topical stabilized retinol treatment induces the expression of HAS genes and HA production in human skin in vitro and in vivo.

PubMed

Li, Wen-Hwa; Wong, Heng-Kuan; Serrano, José; Randhawa, Manpreet; Kaur, Simarna; Southall, Michael D; Parsa, Ramine

2017-05-01

Skin Aging manifests primarily with wrinkles, dyspigmentations, texture changes, and loss of elasticity. During the skin aging process, there is a loss of moisture and elasticity in skin resulting in loss of firmness finally leading to skin sagging. The key molecule involved in skin moisture is hyaluronic acid (HA), which has a significant water-binding capacity. HA levels in skin decline with age resulting in decrease in skin moisture, which may contribute to loss of firmness. Clinical trials have shown that topically applied ROL effectively reduces wrinkles and helps retain youthful appearance. In the current study, ROL was shown to induce HA production and stimulates the gene expression of all three forms of hyaluronic acid synthases (HAS) in normal human epidermal keratinocytes monolayer cultures. Moreover, in human skin equivalent tissues and in human skin explants, topical treatment of tissues with a stabilized-ROL formulation significantly induced the gene expression of HAS mRNA concomitant with an increased HA production. Finally, in a vehicle-controlled human clinical study, histochemical analysis confirmed increased HA accumulation in the epidermis in ROL-treated human skin as compared to vehicle. These results show that ROL increases skin expression of HA, a significant contributing factor responsible for wrinkle formation and skin moisture, which decrease during aging. Taken together with the activity to increase collagen, elastin, and cell proliferation, these studies establish that retinol provides multi-functional activity for photodamaged skin.

bmo-miR-275 down-regulates expression of Bombyx mori sericin gene 2 in vitro

PubMed Central

Qian, Ping; Jiang, Tao; Wang, Xin; Song, Fei; Chen, Chen; Shen, Xingjia

2018-01-01

We hypothesized that bmo-miR-275 has a potential regulatory function regarding the expression of sericin gene 2 (BmSer-2). First, we examined the expression of bmo-miR-275 and its target gene BmSer-2 in seven different tissues from 5th instar day-3 silkworm larvae. The results showed that they were both specifically expressed in the middle silk gland, implying that spatio-temporal conditions are required for bmo-miR-275 to regulate the expression of BmSer-2. To test this hypothesis, we constructed a pri-bmo-miR-275 expressing plasmid pcDNA3.0 [ie1-egfp-pri-bmo-miR-275-SV40] and BmSer-2-3´UTR recombinant reporter plasmids pGL3.0 [A3-luc-Ser-2-3′ UTR-SV40]. Finally, BmN cells were harvested and luciferase activity was detected. Results showed that luciferase activity was reduced significantly (P<0.05) in BmN cells co-transfected with pcDNA3.0 [ie1-egfp-pri-bmo-miR-275-SV40] and pGL3.0 [A3-luc-Ser-2-3’UTR-SV40], suggesting that bmo-miR-275 can down-regulate the expression of BmSer-2 in vitro. Our results improve the understanding of the regulatory function of Bombyx mori miRNA on the expression of genes regulating silk formation. PMID:29381729

Taste receptors and gustatory associated G proteins in channel catfish, Ictalurus punctatus.

PubMed

Gao, Sen; Liu, Shikai; Yao, Jun; Zhou, Tao; Li, Ning; Li, Qi; Dunham, Rex; Liu, Zhanjiang

2017-03-01

Taste sensation plays a pivotal role in nutrient identification and acquisition. This is particularly true for channel catfish (Ictalurus punctatus) that live in turbid waters with limited visibility. This biological process is mainly mediated by taste receptors expressed in taste buds that are distributed in several organs and tissues, including the barbels and skin. In the present study, we identified a complete repertoire of taste receptor and gustatory associated G protein genes in the channel catfish genome. A total of eight taste receptor genes were identified, including five type I and three type II taste receptor genes. Their genomic locations, phylogenetic relations, orthologies and expression were determined. Phylogenetic and collinear analyses provided understanding of the evolution dynamics of this gene family. Furthermore, the motif and dN/dS analyses indicated that selection pressures of different degrees were imposed on these receptors. Additionally, four genes of gustatory associated G proteins were also identified. It was indicated that expression patterns of catfish taste receptors and gustatory associated G proteins across organs mirror the distribution of taste buds across organs. Finally, the expression comparison between catfish and zebrafish organs provided evidence of potential roles of catfish skin and gill involved in taste sensation. Copyright © 2016 Elsevier Inc. All rights reserved.

Ovarian-specific expression of a new gene regulated by the goat PIS region and transcribed by a FOXL2 bidirectional promoter.

PubMed

Pannetier, Maëlle; Renault, Lauriane; Jolivet, Geneviève; Cotinot, Corinne; Pailhoux, Eric

2005-06-01

Studies on XX sex reversal in polled goats (PIS mutation: polled intersex syndrome) have led to the discovery of a female-specific locus crucial for ovarian differentiation. This genomic region is composed of at least two genes, FOXL2 and PISRT1, sharing a common transcriptional regulatory region, PIS. In this paper, we describe a third gene, PFOXic (promoter FOXL2 inverse complementary), located near FOXL2 in the opposite orientation. This gene composed of five exons encodes a 1723-bp cDNA, enclosing two repetitive elements in its 3' end. PFOXic mRNA encodes a putative protein of 163 amino acids with no homologies in any of the databases tested. The transcriptional expression of PFOXic is driven by a bidirectional promoter also enhancing FOXL2 transcription. In goats, PFOXic is expressed in developing ovaries, from 36 days postcoitum until adulthood. Ovarian-specific expression of PFOXic is regulated by the PIS region. PFOXic is found conserved only in Bovidae. But, a human gene located in the opposite orientation relative to FOXL2 can be considered a human PFOXic. Finally, we discuss evidence arguing for regulation of the level of FOXL2 transcription via the bidirectional promoter and the level of transcription of PFOXic.

[Construction and expression of a recombinant adenovirus with LZP3].

PubMed

Chen, Bang-dang; Zhang, Fu-chun; Sun, Mei-yu; Li, Yi-jie; Ma, Zheng-hai

2007-08-01

To explore a new immunocontraceptive vaccine and construct an attenuated recombinant adenoviral vaccine against Lagurus lagurus zona pellucida 3(LZP3). LZP3 gene was subcloned into the shuttle vector pShuttle-CMV, and then a two-step transformation procedure was employed to construct a recombinant adenoviral plasmid with LZP3, which was digested with Pac I and transfected into HEK293 cells to package recombinant adenovirus particles. Finally, HeLa cells were infected by the recombinant adenovirus. LZP3 gene was detected from the recombinant virus by PCR, and its transcription and expression were analyzed by RT-PCR and Western blot. Recombinant adenovirus vector pAd-LZP3 with LZP3 gene was constructed by homologous recombination in E.coli, and a recombinant adenovirus was obtained by transfecting HEK293 cells with pAd-LZP3. PCR test indicated that LZP3 gene was successfully integrated into the adenoviral genome, and the titer of the recombinant adenovirus reached 1.2x10(10) pfu/L. The transcription and expression of LZP3 gene in the infected HeLa cells were confirmed by RT-PCR and Western blot. The recombinant adenovirus RAd-LZP3 can be successfully expressed in the infected HeLa cells, which lays the foundation for further researches into immunizing animals with RAd-LZP3.

Gene delivery by a steroid-peptide nucleic acid conjugate.

PubMed

Rebuffat, Alexandre G; Nawrocki, Andrea R; Nielsen, Peter E; Bernasconi, Alessio G; Bernal-Mendez, Eloy; Frey, Brigitte M; Frey, Felix J

2002-09-01

We previously introduced a method called steroid-mediated gene delivery (SMGD), which uses steroid receptors as shuttles to facilitate the nuclear uptake of transfected DNA. Here, we describe a SMGD strategy with peptide nucleic acids (PNAs) that allowed linkage of a steroid molecule to a defined position in a plasmid without disturbing its gene expression. We synthesized and tested several bifunctional steroid derivatives [patent in process of nationalization] and finally selected the compound named DEX-bisPNA, a molecule consisting of a dexamethasone moiety linked to a PNA clamp (bisPNA) through a 30-atom chemical spacer. Dex-bisPNA binds to the glucocorticoid receptor (GR) as well as to reporter plasmids containing the corresponding PNA binding sites, translocates the GR from the cytoplasm into the nucleus, and increases the delivery of plasmid to the nucleus, resulting in enhanced GR-dependent expression of the reporter gene. The SMGD effect was more pronounced in growth-arrested cells than in proliferating cells. The specificity for the GR was shown by the reversion of the SMGD effect in the presence of dexamethasone as well as an enhanced expression in GR-positive cells but not in GR-negative cells. Thus, SMGD with PNA is a promising strategy for nonviral gene delivery into target tissues expressing specific steroid receptors.

Interleukin-like EMT inducer regulates partial phenotype switching in MITF-low melanoma cell lines

PubMed Central

Noguchi, Ken; Dalton, Annamarie C.; Howley, Breege V.; McCall, Buckley J.; Yoshida, Akihiro; Diehl, J. Alan

2017-01-01

ILEI (FAM3C) is a secreted factor that contributes to the epithelial-to-mesenchymal transition (EMT), a cell biological process that confers metastatic properties to a tumor cell. Initially, we found that ILEI mRNA is highly expressed in melanoma metastases but not in primary tumors, suggesting that ILEI contributes to the malignant properties of melanoma. While melanoma is not an epithelial cell-derived tumor and does not undergo a traditional EMT, melanoma undergoes a similar process known as phenotype switching in which high (micropthalmia-related transcription factor) MITF expressing (MITF-high) proliferative cells switch to a low expressing (MITF-low) invasive state. We observed that MITF-high proliferative cells express low levels of ILEI (ILEI-low) and MITF-low invasive cells express high levels of ILEI (ILEI-high). We found that inducing phenotype switching towards the MITF-low invasive state increases ILEI mRNA expression, whereas phenotype switching towards the MITF-high proliferative state decreases ILEI mRNA expression. Next, we used in vitro assays to show that knockdown of ILEI attenuates invasive potential but not MITF expression or chemoresistance. Finally, we used gene expression analysis to show that ILEI regulates several genes involved in the MITF-low invasive phenotype including JARID1B, HIF-2α, and BDNF. Gene set enrichment analysis suggested that ILEI-regulated genes are enriched for JUN signaling, a known regulator of the MITF-low invasive phenotype. In conclusion, we demonstrate that phenotype switching regulates ILEI expression, and that ILEI regulates partial phenotype switching in MITF-low melanoma cell lines. PMID:28545079

Gene and genon concept: coding versus regulation

PubMed Central

2007-01-01

We analyse here the definition of the gene in order to distinguish, on the basis of modern insight in molecular biology, what the gene is coding for, namely a specific polypeptide, and how its expression is realized and controlled. Before the coding role of the DNA was discovered, a gene was identified with a specific phenotypic trait, from Mendel through Morgan up to Benzer. Subsequently, however, molecular biologists ventured to define a gene at the level of the DNA sequence in terms of coding. As is becoming ever more evident, the relations between information stored at DNA level and functional products are very intricate, and the regulatory aspects are as important and essential as the information coding for products. This approach led, thus, to a conceptual hybrid that confused coding, regulation and functional aspects. In this essay, we develop a definition of the gene that once again starts from the functional aspect. A cellular function can be represented by a polypeptide or an RNA. In the case of the polypeptide, its biochemical identity is determined by the mRNA prior to translation, and that is where we locate the gene. The steps from specific, but possibly separated sequence fragments at DNA level to that final mRNA then can be analysed in terms of regulation. For that purpose, we coin the new term “genon”. In that manner, we can clearly separate product and regulative information while keeping the fundamental relation between coding and function without the need to introduce a conceptual hybrid. In mRNA, the program regulating the expression of a gene is superimposed onto and added to the coding sequence in cis - we call it the genon. The complementary external control of a given mRNA by trans-acting factors is incorporated in its transgenon. A consequence of this definition is that, in eukaryotes, the gene is, in most cases, not yet present at DNA level. Rather, it is assembled by RNA processing, including differential splicing, from various pieces, as steered by the genon. It emerges finally as an uninterrupted nucleic acid sequence at mRNA level just prior to translation, in faithful correspondence with the amino acid sequence to be produced as a polypeptide. After translation, the genon has fulfilled its role and expires. The distinction between the protein coding information as materialised in the final polypeptide and the processing information represented by the genon allows us to set up a new information theoretic scheme. The standard sequence information determined by the genetic code expresses the relation between coding sequence and product. Backward analysis asks from which coding region in the DNA a given polypeptide originates. The (more interesting) forward analysis asks in how many polypeptides of how many different types a given DNA segment is expressed. This concerns the control of the expression process for which we have introduced the genon concept. Thus, the information theoretic analysis can capture the complementary aspects of coding and regulation, of gene and genon. PMID:18087760

Expression profiling during arabidopsis/downy mildew interaction reveals a highly-expressed effector that attenuates responses to salicylic acid.

PubMed

Asai, Shuta; Rallapalli, Ghanasyam; Piquerez, Sophie J M; Caillaud, Marie-Cécile; Furzer, Oliver J; Ishaque, Naveed; Wirthmueller, Lennart; Fabro, Georgina; Shirasu, Ken; Jones, Jonathan D G

2014-10-01

Plants have evolved strong innate immunity mechanisms, but successful pathogens evade or suppress plant immunity via effectors delivered into the plant cell. Hyaloperonospora arabidopsidis (Hpa) causes downy mildew on Arabidopsis thaliana, and a genome sequence is available for isolate Emoy2. Here, we exploit the availability of genome sequences for Hpa and Arabidopsis to measure gene-expression changes in both Hpa and Arabidopsis simultaneously during infection. Using a high-throughput cDNA tag sequencing method, we reveal expression patterns of Hpa predicted effectors and Arabidopsis genes in compatible and incompatible interactions, and promoter elements associated with Hpa genes expressed during infection. By resequencing Hpa isolate Waco9, we found it evades Arabidopsis resistance gene RPP1 through deletion of the cognate recognized effector ATR1. Arabidopsis salicylic acid (SA)-responsive genes including PR1 were activated not only at early time points in the incompatible interaction but also at late time points in the compatible interaction. By histochemical analysis, we found that Hpa suppresses SA-inducible PR1 expression, specifically in the haustoriated cells into which host-translocated effectors are delivered, but not in non-haustoriated adjacent cells. Finally, we found a highly-expressed Hpa effector candidate that suppresses responsiveness to SA. As this approach can be easily applied to host-pathogen interactions for which both host and pathogen genome sequences are available, this work opens the door towards transcriptome studies in infection biology that should help unravel pathogen infection strategies and the mechanisms by which host defense responses are overcome.

A Heme-responsive Regulator Controls Synthesis of Staphyloferrin B in Staphylococcus aureus*♦

PubMed Central

Laakso, Holly A.; Marolda, Cristina L.; Pinter, Tyler B.; Stillman, Martin J.; Heinrichs, David E.

2016-01-01

Staphylococcus aureus possesses a multitude of mechanisms by which it can obtain iron during growth under iron starvation conditions. It expresses an effective heme acquisition system (the iron-regulated surface determinant system), it produces two carboxylate-type siderophores staphyloferrin A and staphyloferrin B (SB), and it expresses transporters for many other siderophores that it does not synthesize. The ferric uptake regulator protein regulates expression of genes encoding all of these systems. Mechanisms of fine-tuning expression of iron-regulated genes, beyond simple iron regulation via ferric uptake regulator, have not been uncovered in this organism. Here, we identify the ninth gene of the sbn operon, sbnI, as encoding a ParB/Spo0J-like protein that is required for expression of genes in the sbn operon from sbnD onward. Expression of sbnD–I is drastically decreased in an sbnI mutant, and the mutant does not synthesize detectable SB during early phases of growth. Thus, SB-mediated iron acquisition is impaired in an sbnI mutant strain. We show that the protein forms dimers and tetramers in solution and binds to DNA within the sbnC coding region. Moreover, we show that SbnI binds heme and that heme-bound SbnI does not bind DNA. Finally, we show that providing exogenous heme to S. aureus growing in an iron-free medium results in delayed synthesis of SB. This is the first study in S. aureus that identifies a DNA-binding regulatory protein that senses heme to control gene expression for siderophore synthesis. PMID:26534960

The Hippo pathway member Yap plays a key role in influencing fate decisions in muscle satellite cells

PubMed Central

Judson, Robert N.; Tremblay, Annie M.; Knopp, Paul; White, Robert B.; Urcia, Roby; De Bari, Cosimo; Zammit, Peter S.; Camargo, Fernando D.; Wackerhage, Henning

2012-01-01

Summary Satellite cells are the resident stem cells of skeletal muscle. Mitotically quiescent in mature muscle, they can be activated to proliferate and generate myoblasts to supply further myonuclei to hypertrophying or regenerating muscle fibres, or self-renew to maintain the resident stem cell pool. Here, we identify the transcriptional co-factor Yap as a novel regulator of satellite cell fate decisions. Yap expression increases during satellite cell activation and Yap remains highly expressed until after the differentiation versus self-renewal decision is made. Constitutive expression of Yap maintains Pax7+ and MyoD+ satellite cells and satellite cell-derived myoblasts, promotes proliferation but prevents differentiation. In contrast, Yap knockdown reduces the proliferation of satellite cell-derived myoblasts by ≈40%. Consistent with the cellular phenotype, microarrays show that Yap increases expression of genes associated with Yap inhibition, the cell cycle, ribosome biogenesis and that it represses several genes associated with angiotensin signalling. We also identify known regulators of satellite cell function such as BMP4, CD34 and Myf6 (Mrf4) as genes whose expression is dependent on Yap activity. Finally, we confirm in myoblasts that Yap binds to Tead transcription factors and co-activates MCAT elements which are enriched in the proximal promoters of Yap-responsive genes. PMID:23038772

A part toolbox to tune genetic expression in Bacillus subtilis

PubMed Central

Guiziou, Sarah; Sauveplane, Vincent; Chang, Hung-Ju; Clerté, Caroline; Declerck, Nathalie; Jules, Matthieu; Bonnet, Jerome

2016-01-01

Libraries of well-characterised components regulating gene expression levels are essential to many synthetic biology applications. While widely available for the Gram-negative model bacterium Escherichia coli, such libraries are lacking for the Gram-positive model Bacillus subtilis, a key organism for basic research and biotechnological applications. Here, we engineered a genetic toolbox comprising libraries of promoters, Ribosome Binding Sites (RBS), and protein degradation tags to precisely tune gene expression in B. subtilis. We first designed a modular Expression Operating Unit (EOU) facilitating parts assembly and modifications and providing a standard genetic context for gene circuits implementation. We then selected native, constitutive promoters of B. subtilis and efficient RBS sequences from which we engineered three promoters and three RBS sequence libraries exhibiting ∼14 000-fold dynamic range in gene expression levels. We also designed a collection of SsrA proteolysis tags of variable strength. Finally, by using fluorescence fluctuation methods coupled with two-photon microscopy, we quantified the absolute concentration of GFP in a subset of strains from the library. Our complete promoters and RBS sequences library comprising over 135 constructs enables tuning of GFP concentration over five orders of magnitude, from 0.05 to 700 μM. This toolbox of regulatory components will support many research and engineering applications in B. subtilis. PMID:27402159

Formation of Nitrogenase NifDK Tetramers in the Mitochondria of Saccharomyces cerevisiae

PubMed Central

2017-01-01

Transferring the prokaryotic enzyme nitrogenase into a eukaryotic host with the final aim of developing N2 fixing cereal crops would revolutionize agricultural systems worldwide. Targeting it to mitochondria has potential advantages because of the organelle’s high O2 consumption and the presence of bacterial-type iron–sulfur cluster biosynthetic machinery. In this study, we constructed 96 strains of Saccharomyces cerevisiae in which transcriptional units comprising nine Azotobacter vinelandii nif genes (nifHDKUSMBEN) were integrated into the genome. Two combinatorial libraries of nif gene clusters were constructed: a library of mitochondrial leading sequences consisting of 24 clusters within four subsets of nif gene expression strength, and an expression library of 72 clusters with fixed mitochondrial leading sequences and nif expression levels assigned according to factorial design. In total, 29 promoters and 18 terminators were combined to adjust nif gene expression levels. Expression and mitochondrial targeting was confirmed at the protein level as immunoblot analysis showed that Nif proteins could be efficiently accumulated in mitochondria. NifDK tetramer formation, an essential step of nitrogenase assembly, was experimentally proven both in cell-free extracts and in purified NifDK preparations. This work represents a first step toward obtaining functional nitrogenase in the mitochondria of a eukaryotic cell. PMID:28221768

Characterisation, analysis of expression and localisation of circadian clock genes from the perspective of photoperiodism in the aphid Acyrthosiphon pisum.

PubMed

Barberà, Miquel; Collantes-Alegre, Jorge Mariano; Martínez-Torres, David

2017-04-01

Aphids are typical photoperiodic insects that switch from viviparous parthenogenetic reproduction typical of long day seasons to oviparous sexual reproduction triggered by the shortening of photoperiod in autumn yielding an overwintering egg in which an embryonic diapause takes place. While the involvement of the circadian clock genes in photoperiodism in mammals is well established, there is still some controversy on their participation in insects. The availability of the genome of the pea aphid Acyrthosiphon pisum places this species as an excellent model to investigate the involvement of the circadian system in the aphid seasonal response. In the present report, we have advanced in the characterisation of the circadian clock genes and showed that these genes display extensive alternative splicing. Moreover, the expression of circadian clock genes, analysed at different moments of the day, showed a robust cycling of central clock genes period and timeless. Furthermore, the rhythmic expression of these genes was shown to be rapidly dampened under DD (continuous darkness conditions), thus supporting the model of a seasonal response based on a heavily dampened circadian oscillator. Additionally, increased expression of some of the circadian clock genes under short-day conditions suggest their involvement in the induction of the aphid seasonal response. Finally, in situ localisation of transcripts of genes period and timeless in the aphid brain revealed the site of clock neurons for the first time in aphids. Two groups of clock cells were identified: the Dorsal Neurons (DN) and the Lateral Neurons (LN), both in the protocerebrum. Copyright © 2017 Elsevier Ltd. All rights reserved.

Transcriptional responses in Lactococcus lactis subsp. cremoris to the changes in oxygen and redox potential during milk acidification.

PubMed

Larsen, N; Brøsted Werner, B; Jespersen, L

2016-08-01

Milk acidification and metabolic activity of the starter cultures are affected by oxygen; however, molecular factors related to the redox changes are poorly defined. The objective of the study was to investigate transcriptional responses in Lactococcus lactis subsp. cremoris CHCCO2 grown in milk to the shifts of oxygen and redox potential (Eh7 ). Transcriptomic studies were performed with the use of Illumina HiSeq 2000 mRNA sequencing and validated by the real-time quantitative PCR. In total 105 differentially expressed genes were assigned functional gene names. Most of the differentially expressed genes were detected during aerobic reduction phase. Upregulated genes were implicated in lactose utilization, glycogen biosynthesis, amino sugar metabolism, oxidation-reduction, pyrimidine biosynthesis and DNA integration processes. Genes of purine nucleotide biosynthesis and genes encoding amino acid, multidrug resistance and ion ABC transporters were mostly downregulated, while oligopeptide transporter genes were reduced during oxygen depletion and induced at minimum Eh7 . Understanding of gene responses in starter cultures to the changes of oxidation-reduction state is important for the better control and reproducibility of dairy fermentations. We applied mRNA sequencing by Illumina HiSeq 2000 to investigate gene expression profile in a dairy strain of Lactococcus lactis subsp. cremoris during milk acidification. Novelty of this study lies in linking transcriptional responses to oxygen depletion and the changes of redox potential with the fermentation kinetics and clarification of molecular factors specifically expressed in milk which might be essential for bacterial performance and the final quality of cheeses. © 2016 The Society for Applied Microbiology.

Genome-wide characterization of phenylalanine ammonia-lyase gene family in watermelon (Citrullus lanatus).

PubMed

Dong, Chun-Juan; Shang, Qing-Mao

2013-07-01

Phenylalanine ammonia-lyase (PAL), the first enzyme in the phenylpropanoid pathway, plays a critical role in plant growth, development, and adaptation. PAL enzymes are encoded by a gene family in plants. Here, we report a genome-wide search for PAL genes in watermelon. A total of 12 PAL genes, designated ClPAL1-12, are identified . Nine are arranged in tandem in two duplication blocks located on chromosomes 4 and 7, and the other three ClPAL genes are distributed as single copies on chromosomes 2, 3, and 8. Both the cDNA and protein sequences of ClPALs share an overall high identity with each other. A phylogenetic analysis places 11 of the ClPALs into a separate cucurbit subclade, whereas ClPAL2, which belongs to neither monocots nor dicots, may serve as an ancestral PAL in plants. In the cucurbit subclade, seven ClPALs form homologous pairs with their counterparts from cucumber. Expression profiling reveals that 11 of the ClPAL genes are expressed and show preferential expression in the stems and male and female flowers. Six of the 12 ClPALs are moderately or strongly expressed in the fruits, particularly in the pulp, suggesting the potential roles of PAL in the development of fruit color and flavor. A promoter motif analysis of the ClPAL genes implies redundant but distinctive cis-regulatory structures for stress responsiveness. Finally, duplication events during the evolution and expansion of the ClPAL gene family are discussed, and the relationships between the ClPAL genes and their cucumber orthologs are estimated.

The Bioinformatic Analysis of the Dysregulated Genes and MicroRNAs in Entorhinal Cortex, Hippocampus, and Blood for Alzheimer's Disease

PubMed Central

Pang, Xiaocong; Zhao, Ying; Wang, Jinhua; Zhou, Qimeng; Xu, Lvjie; Kang, De

2017-01-01

Aim The incidence of Alzheimer's disease (AD) has been increasing in recent years, but there exists no cure and the pathological mechanisms are not fully understood. This study aimed to find out the pathogenesis of learning and memory impairment, new biomarkers, potential therapeutic targets, and drugs for AD. Methods We downloaded the microarray data of entorhinal cortex (EC) and hippocampus (HIP) of AD and controls from Gene Expression Omnibus (GEO) database, and then the differentially expressed genes (DEGs) in EC and HIP regions were analyzed for functional and pathway enrichment. Furthermore, we utilized the DEGs to construct coexpression networks to identify hub genes and discover the small molecules which were capable of reversing the gene expression profile of AD. Finally, we also analyzed microarray and RNA-seq dataset of blood samples to find the biomarkers related to gene expression in brain. Results We found some functional hub genes, such as ErbB2, ErbB4, OCT3, MIF, CDK13, and GPI. According to GO and KEGG pathway enrichment, several pathways were significantly dysregulated in EC and HIP. CTSD and VCAM1 were dysregulated significantly in blood, EC, and HIP, which were potential biomarkers for AD. Target genes of four microRNAs had similar GO_terms distribution with DEGs in EC and HIP. In addtion, small molecules were screened out for AD treatment. Conclusion These biological pathways and DEGs or hub genes will be useful to elucidate AD pathogenesis and identify novel biomarkers or drug targets for developing improved diagnostics and therapeutics against AD. PMID:29359159

A Systematic Investigation into Aging Related Genes in Brain and Their Relationship with Alzheimer's Disease.

PubMed

Meng, Guofeng; Zhong, Xiaoyan; Mei, Hongkang

2016-01-01

Aging, as a complex biological process, is accompanied by the accumulation of functional loses at different levels, which makes age to be the biggest risk factor to many neurological diseases. Even following decades of investigation, the process of aging is still far from being fully understood, especially at a systematic level. In this study, we identified aging related genes in brain by collecting the ones with sustained and consistent gene expression or DNA methylation changes in the aging process. Functional analysis with Gene Ontology to these genes suggested transcriptional regulators to be the most affected genes in the aging process. Transcription regulation analysis found some transcription factors, especially Specificity Protein 1 (SP1), to play important roles in regulating aging related gene expression. Module-based functional analysis indicated these genes to be associated with many well-known aging related pathways, supporting the validity of our approach to select aging related genes. Finally, we investigated the roles of aging related genes on Alzheimer's Disease (AD). We found that aging and AD related genes both involved some common pathways, which provided a possible explanation why aging made the brain more vulnerable to Alzheimer's Disease.

The Arabidopsis transcription factor AtTCP15 regulates endoreduplication by modulating expression of key cell-cycle genes.

PubMed

Li, Zi-Yu; Li, Bin; Dong, Ai-Wu

2012-01-01

Plant cells frequently undergo endoreduplication, a modified cell cycle in which genome is repeatedly replicated without cytokinesis. As the key step to achieve final size and function for cells, endoreduplication is prevalent during plant development. However, mechanisms to control the balance between endoreduplication and mitotic cell division are still poorly understood. Here, we show that the Arabidopsis TCP (CINCINNATA-like TEOSINTE BRANCHED1-CYCLOIDEA-PCF)-family transcription factor gene AtTCP15 is expressed in trichomes, as well as in rapidly dividing and vascular tissues. Expression of AtTCP15SRDX, AtTCP15 fused with a SRDX repressor domain, induces extra endoreduplication in trichomes and cotyledon cells in transgenic Arabidopsis. On the contrary, overexpression of AtTCP15 suppresses endoreduplication in trichomes and other examined cells. Misregulation of AtTCP15 affects the expression of several important genes involved in cell-cycle regulation. AtTCP15 protein binds directly to the promoter regions of CYCA2;3 and RETINOBLASTOMA-RELATED (RBR) genes, which play key roles in endoreduplication. Taken together, AtTCP15 plays an important role in regulating endoreduplication during Arabidopsis development.

Genome-wide Hi-C analysis reveals extensive hierarchical chromatin interactions in rice.

PubMed

Dong, Qianli; Li, Ning; Li, Xiaochong; Yuan, Zan; Xie, Dejian; Wang, Xiaofei; Li, Jianing; Yu, Yanan; Wang, Jinbin; Ding, Baoxu; Zhang, Zhibin; Li, Changping; Bian, Yao; Zhang, Ai; Wu, Ying; Liu, Bao; Gong, Lei

2018-06-01

The non-random spatial packing of chromosomes in the nucleus plays a critical role in orchestrating gene expression and genome function. Here, we present a Hi-C analysis of the chromatin interaction patterns in rice (Oryza sativa L.) at hierarchical architectural levels. We confirm that rice chromosomes occupy their own territories with certain preferential inter-chromosomal associations. Moderate compartment delimitation and extensive TADs (Topologically Associated Domains) were determined to be associated with heterogeneous genomic compositions and epigenetic marks in the rice genome. We found subtle features including chromatin loops, gene loops, and off-/near-diagonal intensive interaction regions. Gene chromatin loops associated with H3K27me3 could be positively involved in gene expression. In addition to insulated enhancing effects for neighbor gene expression, the identified rice gene loops could bi-directionally (+/-) affect the expression of looped genes themselves. Finally, web-interleaved off-diagonal IHIs/KEEs (Interactive Heterochromatic Islands or KNOT ENGAGED ELEMENTs) could trap transposable elements (TEs) via the enrichment of silencing epigenetic marks. In parallel, the near-diagonal FIREs (Frequently Interacting Regions) could positively affect the expression of involved genes. Our results suggest that the chromatin packing pattern in rice is generally similar to that in Arabidopsis thaliana but with clear differences at specific structural levels. We conclude that genomic composition, epigenetic modification, and transcriptional activity could act in combination to shape global and local chromatin packing in rice. Our results confirm recent observations in rice and A. thaliana but also provide additional insights into the patterns and features of chromatin organization in higher plants. © 2018 The Authors. The Plant Journal published by John Wiley & Sons Ltd and Society for Experimental Biology.

A small system--high-resolution study of metabolic adaptation in the central metabolic pathway to temperate climates in Drosophila melanogaster.

PubMed

Lavington, Erik; Cogni, Rodrigo; Kuczynski, Caitlin; Koury, Spencer; Behrman, Emily L; O'Brien, Katherine R; Schmidt, Paul S; Eanes, Walter F

2014-08-01

In this article, we couple the geographic variation in 127 single-nucleotide polymorphism (SNP) frequencies in genes of 46 enzymes of central metabolism with their associated cis-expression variation to predict latitudinal or climatic-driven gene expression changes in the metabolic architecture of Drosophila melanogaster. Forty-two percent of the SNPs in 65% of the genes show statistically significant clines in frequency with latitude across the 20 local population samples collected from southern Florida to Ontario. A number of SNPs in the screened genes are also associated with significant expression variation within the Raleigh population from North Carolina. A principal component analysis of the full variance-covariance matrix of latitudinal changes in SNP-associated standardized gene expression allows us to identify those major genes in the pathway and its associated branches that are likely targets of natural selection. When embedded in a central metabolic context, we show that these apparent targets are concentrated in the genes of the upper glycolytic pathway and pentose shunt, those controlling glycerol shuttle activity, and finally those enzymes associated with the utilization of glutamate and pyruvate. These metabolites possess high connectivity and thus may be the points where flux balance can be best shifted. We also propose that these points are conserved points associated with coupling energy homeostasis and energy sensing in mammals. We speculate that the modulation of gene expression at specific points in central metabolism that are associated with shifting flux balance or possibly energy-state sensing plays a role in adaptation to climatic variation. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Errors in CGAP xProfiler and cDNA DGED: the importance of library parsing and gene selection algorithms.

PubMed

Milnthorpe, Andrew T; Soloviev, Mikhail

2011-04-15

The Cancer Genome Anatomy Project (CGAP) xProfiler and cDNA Digital Gene Expression Displayer (DGED) have been made available to the scientific community over a decade ago and since then were used widely to find genes which are differentially expressed between cancer and normal tissues. The tissue types are usually chosen according to the ontology hierarchy developed by NCBI. The xProfiler uses an internally available flat file database to determine the presence or absence of genes in the chosen libraries, while cDNA DGED uses the publicly available UniGene Expression and Gene relational databases to count the sequences found for each gene in the presented libraries. We discovered that the CGAP approach often includes libraries from dependent or irrelevant tissues (one third of libraries were incorrect on average, with some tissue searches no correct libraries being selected at all). We also discovered that the CGAP approach reported genes from outside the selected libraries and may omit genes found within the libraries. Other errors include the incorrect estimation of the significance values and inaccurate settings for the library size cut-off values. We advocated a revised approach to finding libraries associated with tissues. In doing so, libraries from dependent or irrelevant tissues do not get included in the final library pool. We also revised the method for determining the presence or absence of a gene by searching the UniGene relational database, revised calculation of statistical significance and sorted the library cut-off filter. Our results justify re-evaluation of all previously reported results where NCBI CGAP expression data and tools were used.

Errors in CGAP xProfiler and cDNA DGED: the importance of library parsing and gene selection algorithms

PubMed Central

2011-01-01

Background The Cancer Genome Anatomy Project (CGAP) xProfiler and cDNA Digital Gene Expression Displayer (DGED) have been made available to the scientific community over a decade ago and since then were used widely to find genes which are differentially expressed between cancer and normal tissues. The tissue types are usually chosen according to the ontology hierarchy developed by NCBI. The xProfiler uses an internally available flat file database to determine the presence or absence of genes in the chosen libraries, while cDNA DGED uses the publicly available UniGene Expression and Gene relational databases to count the sequences found for each gene in the presented libraries. Results We discovered that the CGAP approach often includes libraries from dependent or irrelevant tissues (one third of libraries were incorrect on average, with some tissue searches no correct libraries being selected at all). We also discovered that the CGAP approach reported genes from outside the selected libraries and may omit genes found within the libraries. Other errors include the incorrect estimation of the significance values and inaccurate settings for the library size cut-off values. We advocated a revised approach to finding libraries associated with tissues. In doing so, libraries from dependent or irrelevant tissues do not get included in the final library pool. We also revised the method for determining the presence or absence of a gene by searching the UniGene relational database, revised calculation of statistical significance and sorted the library cut-off filter. Conclusion Our results justify re-evaluation of all previously reported results where NCBI CGAP expression data and tools were used. PMID:21496233

3-Deazaneplanocin A suppresses aggressive phenotype-related gene expression in an oral squamous cell carcinoma cell line

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hatta, Mitsutoki, E-mail: hatta@college.fdcnet.ac.jp; Naganuma, Kaori; Kato, Kenichi

In tumor tissues, alterations of gene expression caused by aberrant epigenetic modifications confer phenotypic diversity on malignant cells. Although 3-deazaneplanocin A (DZNep) has been shown to reactivate tumor suppressor genes in several cancer cells, it remains unclear whether DZNep attenuates the malignant phenotypes of oral squamous cell carcinoma (OSCC) cells. In this study, we investigated the effect of DZNep on the expression of genes related to aggressive phenotypes, such as epithelial–mesenchymal transition, in OSCC cells. We found that DZNep reduced the cellular levels of polycomb group proteins (EZH2, SUZ12, BMI1, and RING1A) and the associated trimethylation of Lys27 on histonemore » H3 and monoubiquitination of Lys119 on histone H2A in the poorly differentiated OSCC cell line SAS. Immunocytochemical staining demonstrated that DZNep induced the reorganization of filamentous actin and the membrane localization of E-cadherin associated with cell–cell adhesions. We also found an inhibitory effect of DZNep on cell proliferation using a WST assay. Finally, quantitative RT-PCR analysis demonstrated that genes involved in the aggressive phenotypes (TWIST2, EGFR, ACTA2, TGFB1, WNT5B, and APLIN) were down-regulated, whereas epithelial phenotype genes (CDH1, CLDN4, IVL, and TGM1) were up-regulated in SAS cells treated with DZNep. Collectively, our findings suggest that DZNep reverses the aggressive characteristics of OSCC cells through the dynamic regulation of epithelial plasticity via the reprogramming of gene expression patterns. - Highlights: • DZNep reduced PcG proteins and associated histone modifications in OSCC cells. • DZNep enhanced cell–cell adhesion indicative of epithelial phenotype in OSCC cells. • DZNep suppressed the aggressive phenotype-related gene expression in OSCC cells. • DZNep activated the gene expression of epithelial markers in OSCC cells.« less

The targeting expression of the vascular endothelial growth factor gene in endothelial cells regulated by HRE.ppET-1.

PubMed

Zheng, Xiangrong; Zhang, Shangshang; Yang, Yujia; Wang, Xia; Zhong, Le; Yu, Xiaohe

2008-11-01

The success of gene therapy depends largely on the efficacy of gene delivery vector systems that can deliver genes to target organs or cells selectively and efficiently with minimal toxicity. Here, we show that by using the HRE.ppET-1 regulatory element, we were able to restrict expression of the transgene of vascular endothelial growth factor (VEGF) to endothelial cells exclusively in hypoxic conditions. Eukaryotic expression vectors such as pEGFP-HRE.ppET-1, pcDNA3.1-VEGF+Pa, pcDNA3.1-ppET-1+ EGF+Pa, and pcDNA3.1-HRE.ppET-1+VEGF+Pa were constructed by using a series of nuclear molecule handling methods like PCR, enzyme digestion. The recombinant vectors were transfected into HUVEC cells and HL7702 cells by the lipofectin method. GFP expression was observed with a fluorescence microscope to validate the specificity of expression in endothelial cells under the regulation of HRE.ppET-1 element. Cobalt chloride (final concentration 100 mumol/L) was added to the medium to mimic hypoxia in vitro. After transfection of vectors, the expression of VEGF mRNA was detected by RT-PCR, and the expression of VEGF was detected by Western blotting and ELISA methods under normoxia and hypoxia, respectively. The cell proliferation rate was detected by the MTT test. The expression of GFP revealed that the exterior gene was transcripted effectively in endothelial cells regulated by the HRE.ppET-1 element, while the expression of GFP was very weak in nonendothelial cells. The results of RT-PCR, Western blotting and ELISA showed that VEGF gene expression in the pcDNA3.1-HRE.ppET-1+VEGF+Pa group and in the pcDNA3.1-ppET-1+VEGF+Pa group was higher in hypoxia than it was in normoxia (P<0.05). The MTT test showed that the proliferation rate of HUVEC transfected with HPVA under hypoxia exceeded that of the control group. We conclude that the HRE.ppET-1 element was expressed specifically in endothelial cells, and can increase the expression of VEGF in hypoxia and stimulate proliferation of endothelial cells. Taking advantage of these facts could greatly improve the efficiency of gene therapy. The vector would be valuable for various gene transfer studies targeting endothelial cells.

A sequence in the rat Pit-1 gene promoter confers synergistic activation by glucocorticoids and protein kinase-C.

PubMed

Jong, M T; Raaka, B M; Samuels, H H

1994-10-01

The 5'-flanking region of the gene for Pit-1, a pituitary-specific transcription factor, was isolated from a rat liver genomic library and sequenced. Expression of a reporter construct containing Pit-1 promoter sequences linked to the bacterial chloramphenicol acetyltransferase (CAT) gene was assessed by transient transfection in rat pituitary GH4C1 cells. Treatment of transfected cells with either dexamethasone (DEX) for 48 h or the phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) for the final 20 h of the 48-h posttransfection period had minimal effects on CAT expression. However, CAT activity was elevated about 20-fold when transfected cells were treated with both DEX and TPA. This apparent synergistic activation was lost when DEX treatment was also limited to the final 20 h of the 48-h posttransfection period, suggesting that a time-dependent accumulation of a DEX-induced gene product might be involved. This putative DEX-induced product appeared to be relatively stable, because synergistic activation was observed in cells treated with DEX alone for 36 h, followed by a 10-h incubation without DEX before the addition of TPA. The Pit-1 gene promoter region between -210 and -142 from the transcription start site conferred synergistic regulation by DEX and TPA when placed upstream of position -105 in the herpes viral thymidine kinase promoter.(ABSTRACT TRUNCATED AT 250 WORDS)

Orthogonal control of expression mean and variance by epigenetic features at different genomic loci

DOE PAGES

Dey, Siddharth S.; Foley, Jonathan E.; Limsirichai, Prajit; ...

2015-05-05

While gene expression noise has been shown to drive dramatic phenotypic variations, the molecular basis for this variability in mammalian systems is not well understood. Gene expression has been shown to be regulated by promoter architecture and the associated chromatin environment. However, the exact contribution of these two factors in regulating expression noise has not been explored. Using a dual-reporter lentiviral model system, we deconvolved the influence of the promoter sequence to systematically study the contribution of the chromatin environment at different genomic locations in regulating expression noise. By integrating a large-scale analysis to quantify mRNA levels by smFISH andmore » protein levels by flow cytometry in single cells, we found that mean expression and noise are uncorrelated across genomic locations. Furthermore, we showed that this independence could be explained by the orthogonal control of mean expression by the transcript burst size and noise by the burst frequency. Finally, we showed that genomic locations displaying higher expression noise are associated with more repressed chromatin, thereby indicating the contribution of the chromatin environment in regulating expression noise.« less

Transcriptome analysis uncovers Arabidopsis F-BOX STRESS INDUCED 1 as a regulator of jasmonic acid and abscisic acid stress gene expression.

PubMed

Gonzalez, Lauren E; Keller, Kristen; Chan, Karen X; Gessel, Megan M; Thines, Bryan C

2017-07-17

The ubiquitin 26S proteasome system (UPS) selectively degrades cellular proteins, which results in physiological changes to eukaryotic cells. F-box proteins are substrate adaptors within the UPS and are responsible for the diversity of potential protein targets. Plant genomes are enriched in F-box genes, but the vast majority of these have unknown roles. This work investigated the Arabidopsis F-box gene F-BOX STRESS INDUCED 1 (FBS1) for its effects on gene expression in order elucidate its previously unknown biological function. Using publically available Affymetrix ATH1 microarray data, we show that FBS1 is significantly co-expressed in abiotic stresses with other well-characterized stress response genes, including important stress-related transcriptional regulators. This gene suite is most highly expressed in roots under cold and salt stresses. Transcriptome analysis of fbs1-1 knock-out plants grown at a chilling temperature shows that hundreds of genes require FBS1 for appropriate expression, and that these genes are enriched in those having roles in both abiotic and biotic stress responses. Based on both this genome-wide expression data set and quantitative real-time PCR (qPCR) analysis, it is apparent that FBS1 is required for elevated expression of many jasmonic acid (JA) genes that have established roles in combatting environmental stresses, and that it also controls a subset of JA biosynthesis genes. FBS1 also significantly impacts abscisic acid (ABA) regulated genes, but this interaction is more complex, as FBS1 has both positive and negative effects on ABA-inducible and ABA-repressible gene modules. One noteworthy effect of FBS1 on ABA-related stress processes, however, is the restraint it imposes on the expression of multiple class I LIPID TRANSFER PROTEIN (LTP) gene family members that have demonstrated protective effects in water deficit-related stresses. FBS1 impacts plant stress responses by regulating hundreds of genes that respond to the plant stress hormones JA and ABA. The positive effect that FBS1 has on JA processes and the negative effect it has on at least some ABA processes indicates that it in part regulates cellular responses balanced between these two important stress hormones. More broadly then, FBS1 may aid plant cells in switching between certain biotic (JA) and abiotic (ABA) stress responses. Finally, because FBS1 regulates a subset of JA biosynthesis and response genes, we conclude that it might have a role in tuning hormone responses to particular circumstances at the transcriptional level.

Expression stability and selection of optimal reference genes for gene expression normalization in early life stage rainbow trout exposed to cadmium and copper.

PubMed

Shekh, Kamran; Tang, Song; Niyogi, Som; Hecker, Markus

2017-09-01

Gene expression analysis represents a powerful approach to characterize the specific mechanisms by which contaminants interact with organisms. One of the key considerations when conducting gene expression analyses using quantitative real-time reverse transcription-polymerase chain reaction (qPCR) is the selection of appropriate reference genes, which is often overlooked. Specifically, to reach meaningful conclusions when using relative quantification approaches, expression levels of reference genes must be highly stable and cannot vary as a function of experimental conditions. However, to date, information on the stability of commonly used reference genes across developmental stages, tissues and after exposure to contaminants such as metals is lacking for many vertebrate species including teleost fish. Therefore, in this study, we assessed the stability of expression of 8 reference gene candidates in the gills and skin of three different early life-stages of rainbow trout after acute exposure (24h) to two metals, cadmium (Cd) and copper (Cu) using qPCR. Candidate housekeeping genes were: beta actin (b-actin), DNA directed RNA polymerase II subunit I (DRP2), elongation factor-1 alpha (EF1a), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), glucose-6-phosphate dehydrogenase (G6PD), hypoxanthine phosphoribosyltransferase (HPRT), ribosomal protein L8 (RPL8), and 18S ribosomal RNA (18S). Four algorithms, geNorm, NormFinder, BestKeeper, and the comparative ΔCt method were employed to systematically evaluate the expression stability of these candidate genes under control and exposed conditions as well as across three different life-stages. Finally, stability of genes was ranked by taking geometric means of the ranks established by the different methods. Stability of reference genes was ranked in the following order (from lower to higher stability): HPRT

Identification of new participants in the rainbow trout (Oncorhynchus mykiss) oocyte maturation and ovulation processes using cDNA microarrays

PubMed Central

Bobe, Julien; Montfort, Jerôme; Nguyen, Thaovi; Fostier, Alexis

2006-01-01

Background The hormonal control of oocyte maturation and ovulation as well as the molecular mechanisms of nuclear maturation have been thoroughly studied in fish. In contrast, the other molecular events occurring in the ovary during post-vitellogenesis have received far less attention. Methods Nylon microarrays displaying 9152 rainbow trout cDNAs were hybridized using RNA samples originating from ovarian tissue collected during late vitellogenesis, post-vitellogenesis and oocyte maturation. Differentially expressed genes were identified using a statistical analysis. A supervised clustering analysis was performed using only differentially expressed genes in order to identify gene clusters exhibiting similar expression profiles. In addition, specific genes were selected and their preovulatory ovarian expression was analyzed using real-time PCR. Results From the statistical analysis, 310 differentially expressed genes were identified. Among those genes, 90 were up-regulated at the time of oocyte maturation while 220 exhibited an opposite pattern. After clustering analysis, 90 clones belonging to 3 gene clusters exhibiting the most remarkable expression patterns were kept for further analysis. Using real-time PCR analysis, we observed a strong up-regulation of ion and water transport genes such as aquaporin 4 (aqp4) and pendrin (slc26). In addition, a dramatic up-regulation of vasotocin (avt) gene was observed. Furthermore, angiotensin-converting-enzyme 2 (ace2), coagulation factor V (cf5), adam 22, and the chemokine cxcl14 genes exhibited a sharp up-regulation at the time of oocyte maturation. Finally, ovarian aromatase (cyp19a1) exhibited a dramatic down-regulation over the post-vitellogenic period while a down-regulation of Cytidine monophosphate-N-acetylneuraminic acid hydroxylase (cmah) was observed at the time of oocyte maturation. Conclusion We showed the over or under expression of more that 300 genes, most of them being previously unstudied or unknown in the fish preovulatory ovary. Our data confirmed the down-regulation of estrogen synthesis genes during the preovulatory period. In addition, the strong up-regulation of aqp4 and slc26 genes prior to ovulation suggests their participation in the oocyte hydration process occurring at that time. Furthermore, among the most up-regulated clones, several genes such as cxcl14, ace2, adam22, cf5 have pro-inflammatory, vasodilatory, proteolytics and coagulatory functions. The identity and expression patterns of those genes support the theory comparing ovulation to an inflammatory-like reaction. PMID:16872517

The role of aluminum sensing and signaling in plant aluminum resistance.

PubMed

Liu, Jiping; Piñeros, Miguel A; Kochian, Leon V

2014-03-01

As researchers have gained a better understanding in recent years into the physiological, molecular, and genetic basis of how plants deal with aluminum (Al) toxicity in acid soils prevalent in the tropics and sub-tropics, it has become clear that an important component of these responses is the triggering and regulation of cellular pathways and processes by Al. In this review of plant Al signaling, we begin by summarizing the understanding of physiological mechanisms of Al resistance, which first led researchers to realize that Al stress induces gene expression and modifies protein function during the activation of Al resistance responses. Subsequently, an overview of Al resistance genes and their function provides verification that Al induction of gene expression plays a major role in Al resistance in many plant species. More recent research into the mechanistic basis for Al-induced transcriptional activation of resistance genes has led to the identification of several transcription factors as well as cis-elements in the promoters of Al resistance genes that play a role in greater Al-induced gene expression as well as higher constitutive expression of resistance genes in some plant species. Finally, the post-transcriptional and translational regulation of Al resistance proteins is addressed, where recent research has shown that Al can both directly bind to and alter activity of certain organic acid transporters, and also influence Al resistance proteins indirectly, via protein phosphorylation. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Cell-wall polysaccharide composition and glycanase activity of Silene vulgaris callus transformed with rolB and rolC genes.

PubMed

Günter, Elena A; Shkryl, Yury N; Popeyko, Oxana V; Veremeichik, Galina N; Bulgakov, Victor P

2015-03-15

The aim of this research is to investigate the effects of the Agrobacterium rhizogenes rol genes on the composition of cell-wall polysaccharides and glycanase activity in the campion callus. The expression of the rolC gene reduces the yield of campion pectin, while the expression of the rolB or rolC gene inhibits the volumetric production of both pectin and intracellular arabinogalactan. The rol genes are involved in regulating the activity of glycanases and esterases, thereby contributing to the modification of polysaccharide structures, their molecular weight (Mw) and the degree of pectin methyl esterification (DE). The increase in pectin arabinose residue appears to be connected to a decrease in intracellular and extracellular α-l-arabinofuranosidase activity in transgenic campion calluses. In transgenic calluses expressing the rolB and rolC genes, the increase in pectin galactose residue is likely due to a decrease in β-galactosidase activity. The decrease in the Mw of pectin and its d-galacturonic acid content appears to be connected to an increase in extracellular polygalacturonase activity. Finally, the increase in pectinesterase activity causes a decrease in the DE of pectin. Thus, the expression of rolB and rolC genes in campion callus has a considerable effect on pectin's sugar composition, DE and Mw, while it appears to have an insignificant influence on intracellular and extracellular arabinogalactans. Copyright © 2014 Elsevier Ltd. All rights reserved.

Replication-dependent histone genes are actively transcribed in differentiating and aging retinal neurons

PubMed Central

Banday, Abdul Rouf; Baumgartner, Marybeth; Al Seesi, Sahar; Karunakaran, Devi Krishna Priya; Venkatesh, Aditya; Congdon, Sean; Lemoine, Christopher; Kilcollins, Ashley M; Mandoiu, Ion; Punzo, Claudio; Kanadia, Rahul N

2014-01-01

In the mammalian genome, each histone family contains multiple replication-dependent paralogs, which are found in clusters where their transcription is thought to be coupled to the cell cycle. Here, we wanted to interrogate the transcriptional regulation of these paralogs during retinal development and aging. We employed deep sequencing, quantitative PCR, in situ hybridization (ISH), and microarray analysis, which revealed that replication-dependent histone genes were not only transcribed in progenitor cells but also in differentiating neurons. Specifically, by ISH analysis we found that different histone genes were actively transcribed in a subset of neurons between postnatal day 7 and 14. Interestingly, within a histone family, not all paralogs were transcribed at the same level during retinal development. For example, expression of Hist1h1b was higher embryonically, while that of Hist1h1c was higher postnatally. Finally, expression of replication-dependent histone genes was also observed in the aging retina. Moreover, transcription of replication-dependent histones was independent of rapamycin-mediated mTOR pathway inactivation. Overall, our data suggest the existence of variant nucleosomes produced by the differential expression of the replication-dependent histone genes across retinal development. Also, the expression of a subset of replication-dependent histone isotypes in senescent neurons warrants re-examining these genes as “replication-dependent.” Thus, our findings underscore the importance of understanding the transcriptional regulation of replication-dependent histone genes in the maintenance and functioning of neurons. PMID:25486194

Capturing the biological impact of CDKN2A and MC1R genes as an early predisposing event in melanoma and non melanoma skin cancer

PubMed Central

Puig-Butille, Joan Anton; Escámez, María José; Garcia-Garcia, Francisco; Tell-Marti, Gemma; Fabra, Àngels; Martínez-Santamaría, Lucía; Badenas, Celia; Aguilera, Paula; Pevida, Marta; Dopazo, Joaquín; del Río, Marcela; Puig, Susana

2014-01-01

Germline mutations in CDKN2A and/or red hair color variants in MC1R genes are associated with an increased susceptibility to develop cutaneous melanoma or non melanoma skin cancer. We studied the impact of the CDKN2A germinal mutation p.G101W and MC1R variants on gene expression and transcription profiles associated with skin cancer. To this end we set-up primary skin cell co-cultures from siblings of melanoma prone-families that were later analyzed using the expression array approach. As a result, we found that 1535 transcripts were deregulated in CDKN2A mutated cells, with over-expression of immunity-related genes (HLA-DPB1, CLEC2B, IFI44, IFI44L, IFI27, IFIT1, IFIT2, SP110 and IFNK) and down-regulation of genes playing a role in the Notch signaling pathway. 3570 transcripts were deregulated in MC1R variant carriers. In particular, genes related to oxidative stress and DNA damage pathways were up-regulated as well as genes associated with neurodegenerative diseases such as Parkinson’s, Alzheimer and Huntington. Finally, we observed that the expression signatures indentified in phenotypically normal cells carrying CDKN2A mutations or MC1R variants are maintained in skin cancer tumors (melanoma and squamous cell carcinoma). These results indicate that transcriptome deregulation represents an early event critical for skin cancer development. PMID:24742402

Characterization of the transcriptome profiles related to globin gene switching during in vitro erythroid maturation

PubMed Central

2012-01-01

Background The fetal and adult globin genes in the human β-globin cluster on chromosome 11 are sequentially expressed to achieve normal hemoglobin switching during human development. The pharmacological induction of fetal γ-globin (HBG) to replace abnormal adult sickle βS-globin is a successful strategy to treat sickle cell disease; however the molecular mechanism of γ-gene silencing after birth is not fully understood. Therefore, we performed global gene expression profiling using primary erythroid progenitors grown from human peripheral blood mononuclear cells to characterize gene expression patterns during the γ-globin to β-globin (γ/β) switch observed throughout in vitro erythroid differentiation. Results We confirmed erythroid maturation in our culture system using cell morphologic features defined by Giemsa staining and the γ/β-globin switch by reverse transcription-quantitative PCR (RT-qPCR) analysis. We observed maximal γ-globin expression at day 7 with a switch to a predominance of β-globin expression by day 28 and the γ/β-globin switch occurred around day 21. Expression patterns for transcription factors including GATA1, GATA2, KLF1 and NFE2 confirmed our system produced the expected pattern of expression based on the known function of these factors in globin gene regulation. Subsequent gene expression profiling was performed with RNA isolated from progenitors harvested at day 7, 14, 21, and 28 in culture. Three major gene profiles were generated by Principal Component Analysis (PCA). For profile-1 genes, where expression decreased from day 7 to day 28, we identified 2,102 genes down-regulated > 1.5-fold. Ingenuity pathway analysis (IPA) for profile-1 genes demonstrated involvement of the Cdc42, phospholipase C, NF-Kβ, Interleukin-4, and p38 mitogen activated protein kinase (MAPK) signaling pathways. Transcription factors known to be involved in γ-and β-globin regulation were identified. The same approach was used to generate profile-2 genes where expression was up-regulated over 28 days in culture. IPA for the 2,437 genes with > 1.5-fold induction identified the mitotic roles of polo-like kinase, aryl hydrocarbon receptor, cell cycle control, and ATM (Ataxia Telangiectasia Mutated Protein) signaling pathways; transcription factors identified included KLF1, GATA1 and NFE2 among others. Finally, profile-3 was generated from 1,579 genes with maximal expression at day 21, around the time of the γ/β-globin switch. IPA identified associations with cell cycle control, ATM, and aryl hydrocarbon receptor signaling pathways. Conclusions The transcriptome analysis completed with erythroid progenitors grown in vitro identified groups of genes with distinct expression profiles, which function in metabolic pathways associated with cell survival, hematopoiesis, blood cells activation, and inflammatory responses. This study represents the first report of a transcriptome analysis in human primary erythroid progenitors to identify transcription factors involved in hemoglobin switching. Our results also demonstrate that the in vitro liquid culture system is an excellent model to define mechanisms of global gene expression and the DNA-binding protein and signaling pathways involved in globin gene regulation. PMID:22537182

Global gene expression analysis of early response to chemotherapy treatment in ovarian cancer spheroids.

PubMed

L'Espérance, Sylvain; Bachvarova, Magdalena; Tetu, Bernard; Mes-Masson, Anne-Marie; Bachvarov, Dimcho

2008-02-26

Chemotherapy (CT) resistance in ovarian cancer (OC) is broad and encompasses diverse unrelated drugs, suggesting more than one mechanism of resistance. To better understand the molecular mechanisms controlling the immediate response of OC cells to CT exposure, we have performed gene expression profiling in spheroid cultures derived from six OC cell lines (OVCAR3, SKOV3, TOV-112, TOV-21, OV-90 and TOV-155), following treatment with 10,0 microM cisplatin, 2,5 microM paclitaxel or 5,0 microM topotecan for 72 hours. Exposure of OC spheroids to these CT drugs resulted in differential expression of genes associated with cell growth and proliferation, cellular assembly and organization, cell death, cell cycle control and cell signaling. Genes, functionally involved in DNA repair, DNA replication and cell cycle arrest were mostly overexpressed, while genes implicated in metabolism (especially lipid metabolism), signal transduction, immune and inflammatory response, transport, transcription regulation and protein biosynthesis, were commonly suppressed following all treatments. Cisplatin and topotecan treatments triggered similar alterations in gene and pathway expression patterns, while paclitaxel action was mainly associated with induction of genes and pathways linked to cellular assembly and organization (including numerous tubulin genes), cell death and protein synthesis. The microarray data were further confirmed by pathway and network analyses. Most alterations in gene expression were directly related to mechanisms of the cytotoxics actions in OC spheroids. However, the induction of genes linked to mechanisms of DNA replication and repair in cisplatin- and topotecan-treated OC spheroids could be associated with immediate adaptive response to treatment. Similarly, overexpression of different tubulin genes upon exposure to paclitaxel could represent an early compensatory effect to this drug action. Finally, multicellular growth conditions that are known to alter gene expression (including cell adhesion and cytoskeleton organization), could substantially contribute in reducing the initial effectiveness of CT drugs in OC spheroids. Results described in this study underscore the potential of the microarray technology for unraveling the complex mechanisms of CT drugs actions in OC spheroids and early cellular response to treatment.

LEGO: a novel method for gene set over-representation analysis by incorporating network-based gene weights

PubMed Central

Dong, Xinran; Hao, Yun; Wang, Xiao; Tian, Weidong

2016-01-01

Pathway or gene set over-representation analysis (ORA) has become a routine task in functional genomics studies. However, currently widely used ORA tools employ statistical methods such as Fisher’s exact test that reduce a pathway into a list of genes, ignoring the constitutive functional non-equivalent roles of genes and the complex gene-gene interactions. Here, we develop a novel method named LEGO (functional Link Enrichment of Gene Ontology or gene sets) that takes into consideration these two types of information by incorporating network-based gene weights in ORA analysis. In three benchmarks, LEGO achieves better performance than Fisher and three other network-based methods. To further evaluate LEGO’s usefulness, we compare LEGO with five gene expression-based and three pathway topology-based methods using a benchmark of 34 disease gene expression datasets compiled by a recent publication, and show that LEGO is among the top-ranked methods in terms of both sensitivity and prioritization for detecting target KEGG pathways. In addition, we develop a cluster-and-filter approach to reduce the redundancy among the enriched gene sets, making the results more interpretable to biologists. Finally, we apply LEGO to two lists of autism genes, and identify relevant gene sets to autism that could not be found by Fisher. PMID:26750448

LEGO: a novel method for gene set over-representation analysis by incorporating network-based gene weights.

PubMed

Dong, Xinran; Hao, Yun; Wang, Xiao; Tian, Weidong

2016-01-11

Pathway or gene set over-representation analysis (ORA) has become a routine task in functional genomics studies. However, currently widely used ORA tools employ statistical methods such as Fisher's exact test that reduce a pathway into a list of genes, ignoring the constitutive functional non-equivalent roles of genes and the complex gene-gene interactions. Here, we develop a novel method named LEGO (functional Link Enrichment of Gene Ontology or gene sets) that takes into consideration these two types of information by incorporating network-based gene weights in ORA analysis. In three benchmarks, LEGO achieves better performance than Fisher and three other network-based methods. To further evaluate LEGO's usefulness, we compare LEGO with five gene expression-based and three pathway topology-based methods using a benchmark of 34 disease gene expression datasets compiled by a recent publication, and show that LEGO is among the top-ranked methods in terms of both sensitivity and prioritization for detecting target KEGG pathways. In addition, we develop a cluster-and-filter approach to reduce the redundancy among the enriched gene sets, making the results more interpretable to biologists. Finally, we apply LEGO to two lists of autism genes, and identify relevant gene sets to autism that could not be found by Fisher.

Blood-Based Gene Expression Profiles Models for Classification of Subsyndromal Symptomatic Depression and Major Depressive Disorder

PubMed Central

Yu, Shunying; Yuan, Chengmei; Hong, Wu; Wang, Zuowei; Cui, Jian; Shi, Tieliu; Fang, Yiru

2012-01-01

Subsyndromal symptomatic depression (SSD) is a subtype of subthreshold depressive and also lead to significant psychosocial functional impairment as same as major depressive disorder (MDD). Several studies have suggested that SSD is a transitory phenomena in the depression spectrum and is thus considered a subtype of depression. However, the pathophysioloy of depression remain largely obscure and studies on SSD are limited. The present study compared the expression profile and made the classification with the leukocytes by using whole-genome cRNA microarrays among drug-free first-episode subjects with SSD, MDD, and matched controls (8 subjects in each group). Support vector machines (SVMs) were utilized for training and testing on candidate signature expression profiles from signature selection step. Firstly, we identified 63 differentially expressed SSD signatures in contrast to control (P< = 5.0E-4) and 30 differentially expressed MDD signatures in contrast to control, respectively. Then, 123 gene signatures were identified with significantly differential expression level between SSD and MDD. Secondly, in order to conduct priority selection for biomarkers for SSD and MDD together, we selected top gene signatures from each group of pair-wise comparison results, and merged the signatures together to generate better profiles used for clearly classify SSD and MDD sets in the same time. In details, we tried different combination of signatures from the three pair-wise compartmental results and finally determined 48 gene expression signatures with 100% accuracy. Our finding suggested that SSD and MDD did not exhibit the same expressed genome signature with peripheral blood leukocyte, and blood cell–derived RNA of these 48 gene models may have significant value for performing diagnostic functions and classifying SSD, MDD, and healthy controls. PMID:22348066

Mapping heterogeneity in patient-derived melanoma cultures by single-cell RNA-seq

PubMed Central

Loeffler-Wirth, Henry; Hopp, Lydia; Schadendorf, Dirk; Schartl, Manfred; Anderegg, Ulf; Camp, Gray; Treutlein, Barbara; Binder, Hans; Kunz, Manfred

2017-01-01

Recent technological advances in single-cell genomics make it possible to analyze cellular heterogeneity of tumor samples. Here, we applied single-cell RNA-seq to measure the transcriptomes of 307 single cells cultured from three biopsies of three different patients with a BRAF/NRAS wild type, BRAF mutant/NRAS wild type and BRAF wild type/NRAS mutant melanoma metastasis, respectively. Analysis based on self-organizing maps identified sub-populations defined by multiple gene expression modules involved in proliferation, oxidative phosphorylation, pigmentation and cellular stroma. Gene expression modules had prognostic relevance when compared with gene expression data from published melanoma samples and patient survival data. We surveyed kinome expression patterns across sub-populations of the BRAF/NRAS wild type sample and found that CDK4 and CDK2 were consistently highly expressed in the majority of cells, suggesting that these kinases might be involved in melanoma progression. Treatment of cells with the CDK4 inhibitor palbociclib restricted cell proliferation to a similar, and in some cases greater, extent than MAPK inhibitors. Finally, we identified a low abundant sub-population in this sample that highly expressed a module containing ABC transporter ABCB5, surface markers CD271 and CD133, and multiple aldehyde dehydrogenases (ALDHs). Patient-derived cultures of the BRAF mutant/NRAS wild type and BRAF wild type/NRAS mutant metastases showed more homogeneous single-cell gene expression patterns with gene expression modules for proliferation and ABC transporters. Taken together, our results describe an intertumor and intratumor heterogeneity in melanoma short-term cultures which might be relevant for patient survival, and suggest promising targets for new treatment approaches in melanoma therapy. PMID:27903987

Genome-wide patterns of promoter sharing and co-expression in bovine skeletal muscle.

PubMed

Gu, Quan; Nagaraj, Shivashankar H; Hudson, Nicholas J; Dalrymple, Brian P; Reverter, Antonio

2011-01-12

Gene regulation by transcription factors (TF) is species, tissue and time specific. To better understand how the genetic code controls gene expression in bovine muscle we associated gene expression data from developing Longissimus thoracis et lumborum skeletal muscle with bovine promoter sequence information. We created a highly conserved genome-wide promoter landscape comprising 87,408 interactions relating 333 TFs with their 9,242 predicted target genes (TGs). We discovered that the complete set of predicted TGs share an average of 2.75 predicted TF binding sites (TFBSs) and that the average co-expression between a TF and its predicted TGs is higher than the average co-expression between the same TF and all genes. Conversely, pairs of TFs sharing predicted TGs showed a co-expression correlation higher that pairs of TFs not sharing TGs. Finally, we exploited the co-occurrence of predicted TFBS in the context of muscle-derived functionally-coherent modules including cell cycle, mitochondria, immune system, fat metabolism, muscle/glycolysis, and ribosome. Our findings enabled us to reverse engineer a regulatory network of core processes, and correctly identified the involvement of E2F1, GATA2 and NFKB1 in the regulation of cell cycle, fat, and muscle/glycolysis, respectively. The pivotal implication of our research is two-fold: (1) there exists a robust genome-wide expression signal between TFs and their predicted TGs in cattle muscle consistent with the extent of promoter sharing; and (2) this signal can be exploited to recover the cellular mechanisms underpinning transcription regulation of muscle structure and development in bovine. Our study represents the first genome-wide report linking tissue specific co-expression to co-regulation in a non-model vertebrate.

TCF21 and the environmental sensor aryl-hydrocarbon receptor cooperate to activate a pro-inflammatory gene expression program in coronary artery smooth muscle cells

PubMed Central

Nguyen, Trieu; Iyer, Dharini; Liu, Boxiang; Wang, Ting; Sazonova, Olga; Matic, Ljubica Perisic; Maegdefessel, Lars; Quertermous, Thomas

2017-01-01

Both environmental factors and genetic loci have been associated with coronary artery disease (CAD), however gene-gene and gene-environment interactions that might identify molecular mechanisms of risk are not easily studied by human genetic approaches. We have previously identified the transcription factor TCF21 as the causal CAD gene at 6q23.2 and characterized its downstream transcriptional network that is enriched for CAD GWAS genes. Here we investigate the hypothesis that TCF21 interacts with a downstream target gene, the aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor that mediates the cellular response to environmental contaminants, including dioxin and polycyclic aromatic hydrocarbons (e.g., tobacco smoke). Perturbation of TCF21 expression in human coronary artery smooth muscle cells (HCASMC) revealed that TCF21 promotes expression of AHR, its heterodimerization partner ARNT, and cooperates with these factors to upregulate a number of inflammatory downstream disease related genes including IL1A, MMP1, and CYP1A1. TCF21 was shown to bind in AHR, ARNT and downstream target gene loci, and co-localization was noted for AHR-ARNT and TCF21 binding sites genome-wide in regions of HCASMC open chromatin. These regions of co-localization were found to be enriched for GWAS signals associated with cardio-metabolic as well as chronic inflammatory disease phenotypes. Finally, we show that similar to TCF21, AHR gene expression is increased in atherosclerotic lesions in mice in vivo using laser capture microdissection, and AHR protein is localized in human carotid atherosclerotic lesions where it is associated with protein kinases with a critical role in innate immune response. These data suggest that TCF21 can cooperate with AHR to activate an inflammatory gene expression program that is exacerbated by environmental stimuli, and may contribute to the overall risk for CAD. PMID:28481916

NKL homeobox gene activities in hematopoietic stem cells, T-cell development and T-cell leukemia.

PubMed

Nagel, Stefan; Pommerenke, Claudia; Scherr, Michaela; Meyer, Corinna; Kaufmann, Maren; Battmer, Karin; MacLeod, Roderick A F; Drexler, Hans G

2017-01-01

T-cell acute lymphoblastic leukemia (T-ALL) cells represent developmentally arrested T-cell progenitors, subsets of which aberrantly express homeobox genes of the NKL subclass, including TLX1, TLX3, NKX2-1, NKX2-5, NKX3-1 and MSX1. Here, we analyzed the transcriptional landscape of all 48 members of the NKL homeobox gene subclass in CD34+ hematopoietic stem and progenitor cells (HSPCs) and during lymphopoiesis, identifying activities of nine particular genes. Four of these were expressed in HSPCs (HHEX, HLX1, NKX2-3 and NKX3-1) and three in common lymphoid progenitors (HHEX, HLX1 and MSX1). Interestingly, our data indicated downregulation of NKL homeobox gene transcripts in late progenitors and mature T-cells, a phenomenon which might explain the oncogenic impact of this group of genes in T-ALL. Using MSX1-expressing T-ALL cell lines as models, we showed that HHEX activates while HLX1, NKX2-3 and NKX3-1 repress MSX1 transcription, demonstrating the mutual regulation and differential activities of these homeobox genes. Analysis of a public T-ALL expression profiling data set comprising 117 patient samples identified 20 aberrantly activated members of the NKL subclass, extending the number of known NKL homeobox oncogene candidates. While 7/20 genes were also active during hematopoiesis, the remaining 13 showed ectopic expression. Finally, comparative analyses of T-ALL patient and cell line profiling data of NKL-positive and NKL-negative samples indicated absence of shared target genes but instead highlighted deregulation of apoptosis as common oncogenic effect. Taken together, we present a comprehensive survey of NKL homeobox genes in early hematopoiesis, T-cell development and T-ALL, showing that these genes generate an NKL-code for the diverse stages of lymphoid development which might be fundamental for regular differentiation.

NKL homeobox gene activities in hematopoietic stem cells, T-cell development and T-cell leukemia

PubMed Central

Pommerenke, Claudia; Scherr, Michaela; Meyer, Corinna; Kaufmann, Maren; Battmer, Karin; MacLeod, Roderick A. F.; Drexler, Hans G.

2017-01-01

T-cell acute lymphoblastic leukemia (T-ALL) cells represent developmentally arrested T-cell progenitors, subsets of which aberrantly express homeobox genes of the NKL subclass, including TLX1, TLX3, NKX2-1, NKX2-5, NKX3-1 and MSX1. Here, we analyzed the transcriptional landscape of all 48 members of the NKL homeobox gene subclass in CD34+ hematopoietic stem and progenitor cells (HSPCs) and during lymphopoiesis, identifying activities of nine particular genes. Four of these were expressed in HSPCs (HHEX, HLX1, NKX2-3 and NKX3-1) and three in common lymphoid progenitors (HHEX, HLX1 and MSX1). Interestingly, our data indicated downregulation of NKL homeobox gene transcripts in late progenitors and mature T-cells, a phenomenon which might explain the oncogenic impact of this group of genes in T-ALL. Using MSX1-expressing T-ALL cell lines as models, we showed that HHEX activates while HLX1, NKX2-3 and NKX3-1 repress MSX1 transcription, demonstrating the mutual regulation and differential activities of these homeobox genes. Analysis of a public T-ALL expression profiling data set comprising 117 patient samples identified 20 aberrantly activated members of the NKL subclass, extending the number of known NKL homeobox oncogene candidates. While 7/20 genes were also active during hematopoiesis, the remaining 13 showed ectopic expression. Finally, comparative analyses of T-ALL patient and cell line profiling data of NKL-positive and NKL-negative samples indicated absence of shared target genes but instead highlighted deregulation of apoptosis as common oncogenic effect. Taken together, we present a comprehensive survey of NKL homeobox genes in early hematopoiesis, T-cell development and T-ALL, showing that these genes generate an NKL-code for the diverse stages of lymphoid development which might be fundamental for regular differentiation. PMID:28151996

Regulation of NlE74A on vitellogenin might be mediated by angiotensin converting enzyme through a fecundity-related SNP in the brown planthopper, Nilaparvata lugens.

PubMed

Sun, Zhongxiang; Shi, Qi; Xu, Cuicui; Wang, Rumeng; Wang, Huanhuan; Song, Yuanyuan; Zeng, Rensen

2018-06-19

The major yolk protein precursors (YPP) gene, vitellogenin (Vg), usually considered as a reproductive indicator and molecular marker for evaluating insect fecundity, is controlled by insect hormone (mainly ecdysteroids and juvenile hormone), transcription factors and many other fecundity-related genes. To better understand the underlying molecular regulation mechanisms of the NlVg in the brown planthopper Nilaparvata lugens (N. lugens), the correlation between one early ecdysone response gene E74 and one important fecundity-related gene angiotensin converting enzyme (ACE) on the regulation of Vg gene expression, was investigated. We first showed that the mRNA expression level of NlACE were significantly higher in a high-fecundity population (HFP) than a low-fecundity population (LFP) at different development stages, and knockdown of NlACE expression by RNA interference (RNAi) results in a reduced level of NlVg expression and N. lugens fecundity. Subsequently, we analyzed the promoter of NlACE and found an E74A binding site, which was also differentially expressed in HFP and LFP. Then a gene putatively encoding E74A, namely NlE74A, predominant in the ovary and fat body was cloned and characterized. Furthermore, the developmental profile during female adult and the tissue-specific expression pattern of NlACE and NlE74A were similar to the expression pattern of NlVg gene, implying that both NlACE and NlE74A may be involved in regulating the expression of NlVg. Finally, after injecting the dsRNA of NlE74A, the NlACE expression levels were significantly reduced simultaneously at 24 h and 48 h post-injection, and the NlVg expression level was significant reduced at 24 h post-injection and the downswing was more significant at 48 h post-injection. These results imply that regulation of NlE74A on NlVg transcription might be mediated by NlACE through the E74 binding site at the NlACE promoter region in N. lugens. Copyright © 2018. Published by Elsevier Inc.

Genome-Wide Temporal Expression Profiling in Caenorhabditis elegans Identifies a Core Gene Set Related to Long-Term Memory.

PubMed

Freytag, Virginie; Probst, Sabine; Hadziselimovic, Nils; Boglari, Csaba; Hauser, Yannick; Peter, Fabian; Gabor Fenyves, Bank; Milnik, Annette; Demougin, Philippe; Vukojevic, Vanja; de Quervain, Dominique J-F; Papassotiropoulos, Andreas; Stetak, Attila

2017-07-12

The identification of genes related to encoding, storage, and retrieval of memories is a major interest in neuroscience. In the current study, we analyzed the temporal gene expression changes in a neuronal mRNA pool during an olfactory long-term associative memory (LTAM) in Caenorhabditis elegans hermaphrodites. Here, we identified a core set of 712 (538 upregulated and 174 downregulated) genes that follows three distinct temporal peaks demonstrating multiple gene regulation waves in LTAM. Compared with the previously published positive LTAM gene set (Lakhina et al., 2015), 50% of the identified upregulated genes here overlap with the previous dataset, possibly representing stimulus-independent memory-related genes. On the other hand, the remaining genes were not previously identified in positive associative memory and may specifically regulate aversive LTAM. Our results suggest a multistep gene activation process during the formation and retrieval of long-term memory and define general memory-implicated genes as well as conditioning-type-dependent gene sets. SIGNIFICANCE STATEMENT The identification of genes regulating different steps of memory is of major interest in neuroscience. Identification of common memory genes across different learning paradigms and the temporal activation of the genes are poorly studied. Here, we investigated the temporal aspects of Caenorhabditis elegans gene expression changes using aversive olfactory associative long-term memory (LTAM) and identified three major gene activation waves. Like in previous studies, aversive LTAM is also CREB dependent, and CREB activity is necessary immediately after training. Finally, we define a list of memory paradigm-independent core gene sets as well as conditioning-dependent genes. Copyright © 2017 the authors 0270-6474/17/376661-12$15.00/0.

TGFβ2 regulates hypothalamic Trh expression through the TGFβ inducible early gene-1 (TIEG1) during fetal development

PubMed Central

Martínez-Armenta, Miriam; de León-Guerrero, Sol Díaz; Catalán, Ana; Alvarez-Arellano, Lourdes; Uribe, Rosa Maria; Subramaniam, Malayannan; Charli, Jean-Louis; Pérez-Martínez, Leonor

2015-01-01

The hypothalamus regulates the homeostasis of the organism by controlling hormone secretion from the pituitary. The molecular mechanisms that regulate the differentiation of the hypothalamic thyrotropin-releasing hormone (TRH) phenotype are poorly understood. We have previously shown that Klf10 or TGFβ inducible early gene-1 (TIEG1) is enriched in fetal hypothalamic TRH neurons. Here, we show that expression of TGFβ isoforms (1–3) and both TGFβ receptors (TβRI and II) occurs in the hypothalamus concomitantly with the establishment of TRH neurons during late embryonic development. TGFβ2 induces Trh expression via a TIEG1 dependent mechanism. TIEG1 regulates Trh expression through an evolutionary conserved GC rich sequence on the Trh promoter. Finally, in mice deficient in TIEG1, Trh expression is lower than in wild type animals at embryonic day 17. These results indicate that TGFβ signaling, through the upregulation of TIEG1, plays an important role in the establishment of Trh expression in the embryonic hypothalamus. PMID:25448845

The POU Transcription Factor Oct-1 Represses Virus-Induced Interferon A Gene Expression

PubMed Central

Mesplède, Thibault; Island, Marie-Laure; Christeff, Nicolas; Petek, Fahrettin; Doly, Janine; Navarro, Sébastien

2005-01-01

Alpha interferon (IFN-α) and IFN-β are able to interfere with viral infection. They exert a vast array of biologic functions, including growth arrest, cell differentiation, and immune system regulation. This regulation extends from innate immunity to cellular and humoral adaptive immune responses. A strict control of expression is needed to prevent detrimental effects of unregulated IFN. Multiple IFN-A subtypes are coordinately induced in human and mouse cells infected by virus and exhibit differences in expression of their individual mRNAs. We demonstrated that the weakly expressed IFN-A11 gene is negatively regulated after viral infection, due to a distal negative regulatory element, binding homeoprotein pituitary homeobox 1 (Pitx1). Here we show that the POU protein Oct-1 binds in vitro and in vivo to the IFN-A11 promoter and represses IFN-A expression upon interferon regulatory factor overexpression. Furthermore, we show that Oct-1-deficient MEFs exhibit increased in vivo IFN-A gene expression and increased antiviral activity. Finally, the IFN-A expression pattern is modified in Oct-1-deficient MEFs. The broad representation of effective and potent octamer-like sequences within IFN-A promoters suggests an important role for Oct-1 in IFN-A regulation. PMID:16166650

Immunologic applications of conditional gene modification technology in the mouse.

PubMed

Sharma, Suveena; Zhu, Jinfang

2014-04-02

Since the success of homologous recombination in altering mouse genome and the discovery of Cre-loxP system, the combination of these two breakthroughs has created important applications for studying the immune system in the mouse. Here, we briefly summarize the general principles of this technology and its applications in studying immune cell development and responses; such implications include conditional gene knockout and inducible and/or tissue-specific gene over-expression, as well as lineage fate mapping. We then discuss the pros and cons of a few commonly used Cre-expressing mouse lines for studying lymphocyte development and functions. We also raise several general issues, such as efficiency of gene deletion, leaky activity of Cre, and Cre toxicity, all of which may have profound impacts on data interpretation. Finally, we selectively list some useful links to the Web sites as valuable mouse resources. Copyright © 2014 John Wiley & Sons, Inc.

A C. elegans Hox gene switches on, off, on and off again to regulate proliferation, differentiation and morphogenesis.

PubMed

Salser, S J; Kenyon, C

1996-05-01

Hox genes establish body pattern throughout the animal kingdom, but the role these genes play at the cellular level to modify and shape parts of the body remains a mystery. We find that the C. elegans Antennapedia homolog, mab-5, sequentially programs many independent events within individual cell lineages. In one body region, mab-5 first switches ON in a lineage to stimulate proliferation, then OFF to specify epidermal structures, then ON in just one branch of the lineage to promote neuroblast formation, and finally OFF to permit proper sense organ morphology. In a neighboring lineage, continuous mab-5 expression leads to a different pattern of development. Thus, this Hox gene achieves much of its power to diversify the anteroposterior axis through fine spatiotemporal differences in expression coupled with a changing pattern of cellular response.

Single-Molecule Imaging of RNA Splicing in Live Cells.

PubMed

Rino, José; Martin, Robert M; Carvalho, Célia; de Jesus, Ana C; Carmo-Fonseca, Maria

2015-01-01

Expression of genetic information in eukaryotes involves a series of interconnected processes that ultimately determine the quality and amount of proteins in the cell. Many individual steps in gene expression are kinetically coupled, but tools are lacking to determine how temporal relationships between chemical reactions contribute to the output of the final gene product. Here, we describe a strategy that permits direct measurements of intron dynamics in single pre-mRNA molecules in live cells. This approach reveals that splicing can occur much faster than previously proposed and opens new avenues for studying how kinetic mechanisms impact on RNA biogenesis. © 2015 Elsevier Inc. All rights reserved.

Heat shock and prolonged heat stress attenuate neurotoxin and sporulation gene expression in group I Clostridium botulinum strain ATCC 3502

PubMed Central

Selby, Katja; Mascher, Gerald; Somervuo, Panu; Korkeala, Hannu

2017-01-01

Foodborne pathogenic bacteria are exposed to a number of environmental stresses during food processing, storage, and preparation, and in the human body. In order to improve the safety of food, the understanding of molecular stress response mechanisms foodborne pathogens employ is essential. Many response mechanisms that are activated during heat shock may cross-protect bacteria against other environmental stresses. To better understand the molecular mechanisms Clostridium botulinum, the causative agent of botulism, utilizes during acute heat stress and during adaptation to stressfully high temperature, the C. botulinum Group I strain ATCC 3502 was grown in continuous culture at 39°C and exposed to heat shock at 45°C, followed by prolonged heat stress at 45°C to allow adaptation of the culture to the high temperature. Growth in continuous culture was performed to exclude secondary growth phase effects or other environmental impacts on bacterial gene transcription. Changes in global gene expression profiles were studied using DNA microarray hybridization. During acute heat stress, Class I and III heat shock genes as well as members of the SOS regulon were activated. The neurotoxin gene botA and genes encoding the neurotoxin-associated proteins were suppressed throughout the study. Prolonged heat stress led to suppression of the sporulation machinery whereas genes related to chemotaxis and motility were activated. Induced expression of a large proportion of prophage genes was detected, suggesting an important role of acquired genes in the stress resistance of C. botulinum. Finally, changes in the expression of a large number of genes related to carbohydrate and amino acid metabolism indicated remodeling of the cellular metabolism. PMID:28464023

Heat shock and prolonged heat stress attenuate neurotoxin and sporulation gene expression in group I Clostridium botulinum strain ATCC 3502.

PubMed

Selby, Katja; Mascher, Gerald; Somervuo, Panu; Lindström, Miia; Korkeala, Hannu

2017-01-01

Foodborne pathogenic bacteria are exposed to a number of environmental stresses during food processing, storage, and preparation, and in the human body. In order to improve the safety of food, the understanding of molecular stress response mechanisms foodborne pathogens employ is essential. Many response mechanisms that are activated during heat shock may cross-protect bacteria against other environmental stresses. To better understand the molecular mechanisms Clostridium botulinum, the causative agent of botulism, utilizes during acute heat stress and during adaptation to stressfully high temperature, the C. botulinum Group I strain ATCC 3502 was grown in continuous culture at 39°C and exposed to heat shock at 45°C, followed by prolonged heat stress at 45°C to allow adaptation of the culture to the high temperature. Growth in continuous culture was performed to exclude secondary growth phase effects or other environmental impacts on bacterial gene transcription. Changes in global gene expression profiles were studied using DNA microarray hybridization. During acute heat stress, Class I and III heat shock genes as well as members of the SOS regulon were activated. The neurotoxin gene botA and genes encoding the neurotoxin-associated proteins were suppressed throughout the study. Prolonged heat stress led to suppression of the sporulation machinery whereas genes related to chemotaxis and motility were activated. Induced expression of a large proportion of prophage genes was detected, suggesting an important role of acquired genes in the stress resistance of C. botulinum. Finally, changes in the expression of a large number of genes related to carbohydrate and amino acid metabolism indicated remodeling of the cellular metabolism.

Dietary fructooligosaccharides and wheat bran elicit specific and dose-dependent gene expression profiles in the proximal colon epithelia of healthy Fischer 344 rats.

PubMed

Chen, Qixuan; Swist, Eleonora; Beckstead, Jocelyn; Green, Judy; Matias, Fernando; Roberts, Jennifer; Qiao, Cunye; Raju, Jayadev; Brooks, Stephen P J; Scoggan, Kylie A

2011-05-01

Proximal colon epithelial gene responses to diets containing increasing levels of dietary fermentable material (FM) from 2 different sources were measured to determine whether gene expression patterns were independent of the source of FM. Male Fischer 344 rats (10/group) were fed for 6 wk a control diet containing 10% (g/g) cellulose (0% FM); or a 2, 5, or 10% wheat bran (WB) diet (1, 2, 5% FM); or a 2, 5, or 8% fructooligosaccharides (FOS) diet (2, 5, 8% FM). WB and FOS were substituted for cellulose to give a final 10% nondigestible material content including FM. Gene responses were relative to expression in rats fed the control diet. The gene response patterns associated with feeding ∼2% FM (5% WB and 2% FOS) were similar (∼10 gene changes ≥ 1.6-fold; P ≤ 0.01) and involved genes associated with transport (Scnn1g, Mt1a), transcription (Zbtb16, Egr1), immunity (Fkbp5), a gut hormone (Retn1β), and lipid metabolism (Scd2, Insig1). These changes were also similar to those associated with 5% FM but only in rats fed the 10% WB diet. In contrast, the 5% FOS diet (~5% FM) was associated with 68 gene expression changes ≥ 1.6-fold (P ≤ 0.01). The diet with the highest level of fermentation (8% FOS, ~8% FM) was associated with 132 changes ≥ 1.6-fold (P ≤ 0.01), including genes associated with transport, cellular proliferation, oncogene and tumor metastasis, the cell cycle, apoptosis, signal transduction, transcript regulation, immunity, gut hormones, and lipid metabolic processes. These results show that both the amount and source of FM determine proximal colon epithelial gene response patterns in rats.

Gene Expression Profiling Specifies Chemokine, Mitochondrial and Lipid Metabolism Signatures in Leprosy

PubMed Central

Guerreiro, Luana Tatiana Albuquerque; Robottom-Ferreira, Anna Beatriz; Ribeiro-Alves, Marcelo; Toledo-Pinto, Thiago Gomes; Rosa Brito, Tiana; Rosa, Patrícia Sammarco; Sandoval, Felipe Galvan; Jardim, Márcia Rodrigues; Antunes, Sérgio Gomes; Shannon, Edward J.; Sarno, Euzenir Nunes; Pessolani, Maria Cristina Vidal; Williams, Diana Lynn; Moraes, Milton Ozório

2013-01-01

Herein, we performed microarray experiments in Schwann cells infected with live M. leprae and identified novel differentially expressed genes (DEG) in M. leprae infected cells. Also, we selected candidate genes associated or implicated with leprosy in genetic studies and biological experiments. Forty-seven genes were selected for validation in two independent types of samples by multiplex qPCR. First, an in vitro model using THP-1 cells was infected with live Mycobacterium leprae and M. bovis bacillus Calmette-Guérin (BCG). In a second situation, mRNA obtained from nerve biopsies from patients with leprosy or other peripheral neuropathies was tested. We detected DEGs that discriminate M. bovis BCG from M. leprae infection. Specific signatures of susceptible responses after M. leprae infection when compared to BCG lead to repression of genes, including CCL2, CCL3, IL8 and SOD2. The same 47-gene set was screened in nerve biopsies, which corroborated the down-regulation of CCL2 and CCL3 in leprosy, but also evidenced the down-regulation of genes involved in mitochondrial metabolism, and the up-regulation of genes involved in lipid metabolism and ubiquitination. Finally, a gene expression signature from DEG was identified in patients confirmed of having leprosy. A classification tree was able to ascertain 80% of the cases as leprosy or non-leprous peripheral neuropathy based on the expression of only LDLR and CCL4. A general immune and mitochondrial hypo-responsive state occurs in response to M. leprae infection. Also, the most important genes and pathways have been highlighted providing new tools for early diagnosis and treatment of leprosy. PMID:23798993

Predicting selective drug targets in cancer through metabolic networks

PubMed Central

Folger, Ori; Jerby, Livnat; Frezza, Christian; Gottlieb, Eyal; Ruppin, Eytan; Shlomi, Tomer

2011-01-01

The interest in studying metabolic alterations in cancer and their potential role as novel targets for therapy has been rejuvenated in recent years. Here, we report the development of the first genome-scale network model of cancer metabolism, validated by correctly identifying genes essential for cellular proliferation in cancer cell lines. The model predicts 52 cytostatic drug targets, of which 40% are targeted by known, approved or experimental anticancer drugs, and the rest are new. It further predicts combinations of synthetic lethal drug targets, whose synergy is validated using available drug efficacy and gene expression measurements across the NCI-60 cancer cell line collection. Finally, potential selective treatments for specific cancers that depend on cancer type-specific downregulation of gene expression and somatic mutations are compiled. PMID:21694718

Expression of neutrophil gelatinase-associated lipocalin (NGAL) in the gut in Crohn's disease.

PubMed

Thorsvik, Silje; Bakke, Ingunn; van Beelen Granlund, Atle; Røyset, Elin Synnøve; Damås, Jan Kristian; Østvik, Ann Elisabet; Sandvik, Arne Kristian

2018-06-05

The antimicrobial glycoprotein neutrophil gelatinase-associated lipocalin (NGAL) is strongly expressed in several infectious, inflammatory and malignant disorders, among these inflammatory bowel disease (IBD). Fecal and serum NGAL is elevated during active IBD and we have recently shown that fecal NGAL is a novel biomarker for IBD with a test performance comparable to the established fecal biomarker calprotectin. This study examines expression of NGAL in the healthy gut and in Crohn's disease (CD), with emphasis on the previously unexplored small intestine. Pinch biopsies were taken from active and inactive CD in jejunum, ileum and colon and from the same sites in healthy controls. Microarray gene expression showed that the NGAL gene, LCN2, was the second most upregulated among 1820 differentially expressed genes in terminal ileum comparing active CD and controls (FC 5.86, p = 0.027). Based on immunohistochemistry and in situ hybridization findings, this upregulation most likely represented increased expression in epithelial cells. Double immunofluorescence showed NGAL expression in 49% (range 19-70) of Paneth cells (PCs) in control ileum with no change during inflammation. In healthy jejunum, the NGAL expression in PCs was weak to none but markedly increased during active CD. We further found NGAL also in metaplastic PCs in colon. Finally, we show for the first time that NGAL is expressed in enteroendocrine cells in small intestine as well as in colon.

Extensive variation between tissues in allele specific expression in an outbred mammal.

PubMed

Chamberlain, Amanda J; Vander Jagt, Christy J; Hayes, Benjamin J; Khansefid, Majid; Marett, Leah C; Millen, Catriona A; Nguyen, Thuy T T; Goddard, Michael E

2015-11-23

Allele specific gene expression (ASE), with the paternal allele more expressed than the maternal allele or vice versa, appears to be a common phenomenon in humans and mice. In other species the extent of ASE is unknown, and even in humans and mice there are several outstanding questions. These include; to what extent is ASE tissue specific? how often does the direction of allele expression imbalance reverse between tissues? how often is only one of the two alleles expressed? is there a genome wide bias towards expression of the paternal or maternal allele; and finally do genes that are nearby on a chromosome share the same direction of ASE? Here we use gene expression data (RNASeq) from 18 tissues from a single cow to investigate each of these questions in turn, and then validate some of these findings in two tissues from 20 cows. Between 40 and 100 million sequence reads were generated per tissue across three replicate samples for each of the eighteen tissues from the single cow (the discovery dataset). A bovine gene expression atlas was created (the first from RNASeq data), and differentially expressed genes in each tissue were identified. To analyse ASE, we had access to unambiguously phased genotypes for all heterozygous variants in the cow's whole genome sequence, where these variants were homozygous in the whole genome sequence of her sire, and as a result we were able to map reads to parental genomes, to determine SNP and genes showing ASE in each tissue. In total 25,251 heterozygous SNP within 7985 genes were tested for ASE in at least one tissue. ASE was pervasive, 89 % of genes tested had significant ASE in at least one tissue. This large proportion of genes displaying ASE was confirmed in the two tissues in a validation dataset. For individual tissues the proportion of genes showing significant ASE varied from as low as 8-16 % of those tested in thymus to as high as 71-82 % of those tested in lung. There were a number of cases where the direction of allele expression imbalance reversed between tissues. For example the gene SPTY2D1 showed almost complete paternal allele expression in kidney and thymus, and almost complete maternal allele expression in the brain caudal lobe and brain cerebellum. Mono allelic expression (MAE) was common, with 1349 of 4856 genes (28 %) tested with more than one heterozygous SNP showing MAE. Across all tissues, 54.17 % of all genes with ASE favoured the paternal allele. Genes that are closely linked on the chromosome were more likely to show higher expression of the same allele (paternal or maternal) than expected by chance. We identified several long runs of neighbouring genes that showed either paternal or maternal ASE, one example was five adjacent genes (GIMAP8, GIMAP7 copy1, GIMAP4, GIMAP7 copy 2 and GIMAP5) that showed almost exclusive paternal expression in brain caudal lobe. Investigating the extent of ASE across 18 bovine tissues in one cow and two tissues in 20 cows demonstrated 1) ASE is pervasive in cattle, 2) the ASE is often MAE but ranges from MAE to slight overexpression of the major allele, 3) the ASE is most often tissue specific and that more than half the time displays divergent allele specific expression patterns across tissues, 4) across all genes there is a slight bias towards expression of the paternal allele and 5) genes expressing the same parental allele are clustered together more than expected by chance, and there are several runs of large numbers of genes expressing the same parental allele.

Orphan nuclear receptor oestrogen-related receptor γ (ERRγ) plays a key role in hepatic cannabinoid receptor type 1-mediated induction of CYP7A1 gene expression

PubMed Central

Zhang, Yaochen; Kim, Don-Kyu; Lee, Ji-Min; Park, Seung Bum; Jeong, Won-IL; Kim, Seong Heon; Lee, In-Kyu; Lee, Chul-Ho; Chiang, John Y.L.; Choi, Hueng-Sik

2017-01-01

Bile acids are primarily synthesized from cholesterol in the liver and have important roles in dietary lipid absorption and cholesterol homoeostasis. Detailed roles of the orphan nuclear receptors regulating cholesterol 7α-hydroxylase (CYP7A1), the rate-limiting enzyme in bile acid synthesis, have not yet been fully elucidated. In the present study, we report that oestrogen-related receptor γ (ERRγ) is a novel transcriptional regulator of CYP7A1 expression. Activation of cannabinoid receptor type 1 (CB1 receptor) signalling induced ERRγ-mediated transcription of the CYP7A1 gene. Overexpression of ERRγ increased CYP7A1 expression in vitro and in vivo, whereas knockdown of ERRγ attenuated CYP7A1 expression. Deletion analysis of the CYP7A1 gene promoter and a ChIP assay revealed an ERRγ -binding site on the CYP7A1 gene promoter. Small heterodimer partner (SHP) inhibited the transcriptional activity of ERRγ and thus regulated CYP7A1 expression. Overexpression of ERRγ led to increased bile acid levels, whereas an inverse agonist of ERRγ, GSK5182, reduced CYP7A1 expression and bile acid synthesis. Finally, GSK5182 significantly reduced hepatic CB1 receptor-mediated induction of CYP7A1 expression and bile acid synthesis in alcohol-treated mice. These results provide the molecular mechanism linking ERRγ and bile acid metabolism. PMID:26348907

Identification and Characterization of the MADS-Box Genes and Their Contribution to Flower Organ in Carnation (Dianthus caryophyllus L.)

PubMed Central

Zhang, Xiaoni; Wang, Qijian; Yang, Shaozong; Lin, Shengnan; Bao, Manzhu; Wu, Quanshu; Wang, Caiyun; Fu, Xiaopeng

2018-01-01

Dianthus is a large genus containing many species with high ornamental economic value. Extensive breeding strategies permitted an exploration of an improvement in the quality of cultivated carnation, particularly in flowers. However, little is known on the molecular mechanisms of flower development in carnation. Here, we report the identification and description of MADS-box genes in carnation (DcaMADS) with a focus on those involved in flower development and organ identity determination. In this study, 39 MADS-box genes were identified from the carnation genome and transcriptome by the phylogenetic analysis. These genes were categorized into four subgroups (30 MIKCc, two MIKC*, two Mα, and five Mγ). The MADS-box domain, gene structure, and conserved motif compositions of the carnation MADS genes were analysed. Meanwhile, the expression of DcaMADS genes were significantly different in stems, leaves, and flower buds. Further studies were carried out for exploring the expression of DcaMADS genes in individual flower organs, and some crucial DcaMADS genes correlated with their putative function were validated. Finally, a new expression pattern of DcaMADS genes in flower organs of carnation was provided: sepal (three class E genes and two class A genes), petal (two class B genes, two class E genes, and one SHORT VEGETATIVE PHASE (SVP)), stamen (two class B genes, two class E genes, and two class C), styles (two class E genes and two class C), and ovary (two class E genes, two class C, one AGAMOUS-LIKE 6 (AGL6), one SEEDSTICK (STK), one B sister, one SVP, and one Mα). This result proposes a model in floral organ identity of carnation and it may be helpful to further explore the molecular mechanism of flower organ identity in carnation. PMID:29617274

Identification and Characterization of the MADS-Box Genes and Their Contribution to Flower Organ in Carnation (Dianthus caryophyllus L.).

PubMed

Zhang, Xiaoni; Wang, Qijian; Yang, Shaozong; Lin, Shengnan; Bao, Manzhu; Bendahmane, Mohammed; Wu, Quanshu; Wang, Caiyun; Fu, Xiaopeng

2018-04-04

Dianthus is a large genus containing many species with high ornamental economic value. Extensive breeding strategies permitted an exploration of an improvement in the quality of cultivated carnation, particularly in flowers. However, little is known on the molecular mechanisms of flower development in carnation. Here, we report the identification and description of MADS-box genes in carnation ( DcaMADS ) with a focus on those involved in flower development and organ identity determination. In this study, 39 MADS-box genes were identified from the carnation genome and transcriptome by the phylogenetic analysis. These genes were categorized into four subgroups (30 MIKC c , two MIKC*, two Mα, and five Mγ). The MADS-box domain, gene structure, and conserved motif compositions of the carnation MADS genes were analysed. Meanwhile, the expression of DcaMADS genes were significantly different in stems, leaves, and flower buds. Further studies were carried out for exploring the expression of DcaMADS genes in individual flower organs, and some crucial DcaMADS genes correlated with their putative function were validated. Finally, a new expression pattern of DcaMADS genes in flower organs of carnation was provided: sepal (three class E genes and two class A genes), petal (two class B genes, two class E genes, and one SHORT VEGETATIVE PHASE ( SVP )), stamen (two class B genes, two class E genes, and two class C), styles (two class E genes and two class C), and ovary (two class E genes, two class C, one AGAMOUS-LIKE 6 ( AGL6 ), one SEEDSTICK ( STK ), one B sister , one SVP , and one Mα ). This result proposes a model in floral organ identity of carnation and it may be helpful to further explore the molecular mechanism of flower organ identity in carnation.

Signal transduction in the wound response of tomato plants.

PubMed Central

Bowles, D

1998-01-01

The wound response of tomato plants has been extensively studied, and provides a useful model to understand signal transduction events leading from injury to marker gene expression. The principal markers that have been used in these studies are genes encoding proteinase inhibitor (pin) proteins. Activation of pin genes occurs in the wounded leaf and in distant unwounded leaves of the plant. This paper reviews current understanding of signalling pathways in the wounded leaf, and in the systemically responding unwounded leaves. First, the nature of known elicitors and their potential roles in planta are discussed, in particular, oligogalacturonides, jasmonates and the peptide signal, systemin. Inhibitors of wound-induced proteinase inhibitor (pin) expression are also reviewed, with particular reference to phenolics, sulphydryl reagents and fusicoccin. In each section, results obtained from the bioassay are considered within the wider context of data from mutants and from transgenic plants with altered levels of putative signalling components. Following this introduction, current models for pin gene regulation are described and discussed, together with a summary for the involvement of phosphorylation-dephosphorylation in wound signalling. Finally, a new model for wound-induced pin gene expression is presented, arising from recent data from the author's laboratory. PMID:9800210

Distinct gene expression profiles characterize the histopathological stages of disease in Helicobacter-induced mucosa-associated lymphoid tissue lymphoma

PubMed Central

Mueller, Anne; O'Rourke, Jani; Grimm, Jan; Guillemin, Karen; Dixon, Michael F.; Lee, Adrian; Falkow, Stanley

2003-01-01

Long-term colonization of humans with Helicobacter pylori can cause the development of gastric B cell mucosa-associated lymphoid tissue lymphoma, yet little is known about the sequence of molecular steps that accompany disease progression. We used microarray analysis and laser microdissection to identify gene expression profiles characteristic and predictive of the various histopathological stages in a mouse model of the disease. The initial step in lymphoma development is marked by infiltration of reactive lymphocytes into the stomach and the launching of a mucosal immune response. Our analysis uncovered molecular markers of both of these processes, including genes coding for the immunoglobulins and the small proline-rich protein Sprr 2A. The subsequent step is characterized histologically by the antigen-driven proliferation and aggregation of B cells and the gradual appearance of lymphoepithelial lesions. In tissues of this stage, we observed increased expression of genes previously associated with malignancy, including the laminin receptor-1 and the multidrug-resistance channel MDR-1. Finally, we found that the transition to destructive lymphoepithelial lesions and malignant lymphoma is marked by an increase in transcription of a single gene encoding calgranulin A/Mrp-8. PMID:12552104

Use of Walnut Shell Powder to Inhibit Expression of Fe2+-Oxidizing Genes of Acidithiobacillus Ferrooxidans

PubMed Central

Li, Yuhui; Liu, Yehao; Tan, Huifang; Zhang, Yifeng; Yue, Mei

2016-01-01

Acidithiobacillus ferrooxidans is a Gram-negative bacterium that obtains energy by oxidizing Fe2+ or reduced sulfur compounds. This bacterium contributes to the formation of acid mine drainage (AMD). This study determined whether walnut shell powder inhibits the growth of A. ferrooxidans. First, the effects of walnut shell powder on Fe2+ oxidization and H+ production were evaluated. Second, the chemical constituents of walnut shell were isolated to determine the active ingredient(s). Third, the expression of Fe2+-oxidizing genes and rus operon genes was investigated using real-time polymerase chain reaction. Finally, growth curves were plotted, and a bioleaching experiment was performed to confirm the active ingredient(s) in walnut shells. The results indicated that both walnut shell powder and the phenolic fraction exert high inhibitory effects on Fe2+ oxidation and H+ production by A. ferrooxidans cultured in standard 9K medium. The phenolic components exert their inhibitory effects by down-regulating the expression of Fe2+-oxidizing genes and rus operon genes, which significantly decreased the growth of A. ferrooxidans. This study revealed walnut shell powder to be a promising substance for controlling AMD. PMID:27144574

CellLineNavigator: a workbench for cancer cell line analysis

PubMed Central

Krupp, Markus; Itzel, Timo; Maass, Thorsten; Hildebrandt, Andreas; Galle, Peter R.; Teufel, Andreas

2013-01-01

The CellLineNavigator database, freely available at http://www.medicalgenomics.org/celllinenavigator, is a web-based workbench for large scale comparisons of a large collection of diverse cell lines. It aims to support experimental design in the fields of genomics, systems biology and translational biomedical research. Currently, this compendium holds genome wide expression profiles of 317 different cancer cell lines, categorized into 57 different pathological states and 28 individual tissues. To enlarge the scope of CellLineNavigator, the database was furthermore closely linked to commonly used bioinformatics databases and knowledge repositories. To ensure easy data access and search ability, a simple data and an intuitive querying interface were implemented. It allows the user to explore and filter gene expression, focusing on pathological or physiological conditions. For a more complex search, the advanced query interface may be used to query for (i) differentially expressed genes; (ii) pathological or physiological conditions; or (iii) gene names or functional attributes, such as Kyoto Encyclopaedia of Genes and Genomes pathway maps. These queries may also be combined. Finally, CellLineNavigator allows additional advanced analysis of differentially regulated genes by a direct link to the Database for Annotation, Visualization and Integrated Discovery (DAVID) Bioinformatics Resources. PMID:23118487

A sociogenomic perspective on neuroscience in organizational behavior.

PubMed

Spain, Seth M; Harms, P D

2014-01-01

We critically examine the current biological models of individual organizational behavior, with particular emphasis on the roles of genetics and the brain. We demonstrate how approaches to biology in the organizational sciences assume that biological systems are simultaneously causal and essentially static; that genotypes exert constant effects. In contrast, we present a sociogenomic approach to organizational research, which could provide a meta-theoretical framework for understanding organizational behavior. Sociogenomics is an interactionist approach that derives power from its ability to explain how genes and environment operate. The key insight is that both genes and the environment operate by modifying gene expression. This leads to a conception of genetic and environmental effects that is fundamentally dynamic, rather than the static view of classical biometric approaches. We review biometric research within organizational behavior, and contrast these interpretations with a sociogenomic view. We provide a review of gene expression mechanisms that help explain the dynamism observed in individual organizational behavior, particularly factors associated with gene expression in the brain. Finally, we discuss the ethics of genomic and neuroscientific findings for practicing managers and discuss whether it is possible to practically apply these findings in management.

A sociogenomic perspective on neuroscience in organizational behavior

PubMed Central

Spain, Seth M.; Harms, P. D.

2014-01-01

We critically examine the current biological models of individual organizational behavior, with particular emphasis on the roles of genetics and the brain. We demonstrate how approaches to biology in the organizational sciences assume that biological systems are simultaneously causal and essentially static; that genotypes exert constant effects. In contrast, we present a sociogenomic approach to organizational research, which could provide a meta-theoretical framework for understanding organizational behavior. Sociogenomics is an interactionist approach that derives power from its ability to explain how genes and environment operate. The key insight is that both genes and the environment operate by modifying gene expression. This leads to a conception of genetic and environmental effects that is fundamentally dynamic, rather than the static view of classical biometric approaches. We review biometric research within organizational behavior, and contrast these interpretations with a sociogenomic view. We provide a review of gene expression mechanisms that help explain the dynamism observed in individual organizational behavior, particularly factors associated with gene expression in the brain. Finally, we discuss the ethics of genomic and neuroscientific findings for practicing managers and discuss whether it is possible to practically apply these findings in management. PMID:24616682

Identification and Analysis of Mitogen-Activated Protein Kinase (MAPK) Cascades in Fragaria vesca.

PubMed

Zhou, Heying; Ren, Suyue; Han, Yuanfang; Zhang, Qing; Qin, Ling; Xing, Yu

2017-08-13

Mitogen-activated protein kinase (MAPK) cascades are highly conserved signaling modules in eukaryotes, including yeasts, plants and animals. MAPK cascades are responsible for protein phosphorylation during signal transduction events, and typically consist of three protein kinases: MAPK, MAPK kinase, and MAPK kinase kinase. In this current study, we identified a total of 12 FvMAPK , 7 FvMAPKK , 73 FvMAPKKK , and one FvMAPKKKK genes in the recently published Fragaria vesca genome sequence. This work reported the classification, annotation and phylogenetic evaluation of these genes and an assessment of conserved motifs and the expression profiling of members of the gene family were also analyzed here. The expression profiles of the MAPK and MAPKK genes in different organs and fruit developmental stages were further investigated using quantitative real-time reverse transcription PCR (qRT-PCR). Finally, the MAPK and MAPKK expression patterns in response to hormone and abiotic stresses (salt, drought, and high and low temperature) were investigated in fruit and leaves of F. vesca . The results provide a platform for further characterization of the physiological and biochemical functions of MAPK cascades in strawberry.

Germline Chd8 haploinsufficiency alters brain development in mouse

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gompers, Andrea L.; Su-Feher, Linda; Ellegood, Jacob

The chromatin remodeling gene CHD8 represents a central node in neurodevelopmental gene networks implicated in autism. In this paper, we examined the impact of germline heterozygous frameshift Chd8 mutation on neurodevelopment in mice. Chd8 +/ del5 mice displayed normal social interactions with no repetitive behaviors but exhibited cognitive impairment correlated with increased regional brain volume, validating that phenotypes of Chd8 +/ del5 mice overlap pathology reported in humans with CHD8 mutations. We applied network analysis to characterize neurodevelopmental gene expression, revealing widespread transcriptional changes in Chd8 +/ del5 mice across pathways disrupted in neurodevelopmental disorders, including neurogenesis, synaptic processes andmore » neuroimmune signaling. We identified a co-expression module with peak expression in early brain development featuring dysregulation of RNA processing, chromatin remodeling and cell-cycle genes enriched for promoter binding by Chd8, and we validated increased neuronal proliferation and developmental splicing perturbation in Chd8 +/ del5 mice. Finally, this integrative analysis offers an initial picture of the consequences of Chd8 haploinsufficiency for brain development.« less

Large-Scale Cognitive GWAS Meta-Analysis Reveals Tissue-Specific Neural Expression and Potential Nootropic Drug Targets.

PubMed

Lam, Max; Trampush, Joey W; Yu, Jin; Knowles, Emma; Davies, Gail; Liewald, David C; Starr, John M; Djurovic, Srdjan; Melle, Ingrid; Sundet, Kjetil; Christoforou, Andrea; Reinvang, Ivar; DeRosse, Pamela; Lundervold, Astri J; Steen, Vidar M; Espeseth, Thomas; Räikkönen, Katri; Widen, Elisabeth; Palotie, Aarno; Eriksson, Johan G; Giegling, Ina; Konte, Bettina; Roussos, Panos; Giakoumaki, Stella; Burdick, Katherine E; Payton, Antony; Ollier, William; Chiba-Falek, Ornit; Attix, Deborah K; Need, Anna C; Cirulli, Elizabeth T; Voineskos, Aristotle N; Stefanis, Nikos C; Avramopoulos, Dimitrios; Hatzimanolis, Alex; Arking, Dan E; Smyrnis, Nikolaos; Bilder, Robert M; Freimer, Nelson A; Cannon, Tyrone D; London, Edythe; Poldrack, Russell A; Sabb, Fred W; Congdon, Eliza; Conley, Emily Drabant; Scult, Matthew A; Dickinson, Dwight; Straub, Richard E; Donohoe, Gary; Morris, Derek; Corvin, Aiden; Gill, Michael; Hariri, Ahmad R; Weinberger, Daniel R; Pendleton, Neil; Bitsios, Panos; Rujescu, Dan; Lahti, Jari; Le Hellard, Stephanie; Keller, Matthew C; Andreassen, Ole A; Deary, Ian J; Glahn, David C; Malhotra, Anil K; Lencz, Todd

2017-11-28

Here, we present a large (n = 107,207) genome-wide association study (GWAS) of general cognitive ability ("g"), further enhanced by combining results with a large-scale GWAS of educational attainment. We identified 70 independent genomic loci associated with general cognitive ability. Results showed significant enrichment for genes causing Mendelian disorders with an intellectual disability phenotype. Competitive pathway analysis implicated the biological processes of neurogenesis and synaptic regulation, as well as the gene targets of two pharmacologic agents: cinnarizine, a T-type calcium channel blocker, and LY97241, a potassium channel inhibitor. Transcriptome-wide and epigenome-wide analysis revealed that the implicated loci were enriched for genes expressed across all brain regions (most strongly in the cerebellum). Enrichment was exclusive to genes expressed in neurons but not oligodendrocytes or astrocytes. Finally, we report genetic correlations between cognitive ability and disparate phenotypes including psychiatric disorders, several autoimmune disorders, longevity, and maternal age at first birth. Copyright © 2017 The Author(s). Published by Elsevier Inc. All rights reserved.

Impulsive Choice in Mice Lacking Paternal Expression of Grb10 Suggests Intragenomic Conflict in Behavior.

PubMed

Dent, Claire L; Humby, Trevor; Lewis, Katie; Ward, Andrew; Fischer-Colbrie, Reiner; Wilkinson, Lawrence S; Wilkins, Jon F; Isles, Anthony R

2018-05-01

Imprinted genes are expressed from one parental allele only as a consequence of epigenetic events that take place in the mammalian germ line and are thought to have evolved through intragenomic conflict between parental alleles. We demonstrate, for the first time, oppositional effects of imprinted genes on brain and behavior. Specifically, we show that mice lacking paternal Grb10 make fewer impulsive choices, with no dissociable effects on a separate measure of impulsive action. Taken together with previous work showing that mice lacking maternal Nesp55 make more impulsive choices, this suggests that impulsive choice behavior is a substrate for the action of genomic imprinting. Moreover, the contrasting effect of these two genes suggests that impulsive choices are subject to intragenomic conflict and that maternal and paternal interests pull this behavior in opposite directions. Finally, these data may also indicate that an imbalance in expression of imprinted genes contributes to pathological conditions such as gambling and drug addiction, where impulsive behavior becomes maladaptive. Copyright © 2018 Dent et al.

Germline Chd8 haploinsufficiency alters brain development in mouse

DOE PAGES

Gompers, Andrea L.; Su-Feher, Linda; Ellegood, Jacob; ...

2017-06-26

The chromatin remodeling gene CHD8 represents a central node in neurodevelopmental gene networks implicated in autism. In this paper, we examined the impact of germline heterozygous frameshift Chd8 mutation on neurodevelopment in mice. Chd8 +/ del5 mice displayed normal social interactions with no repetitive behaviors but exhibited cognitive impairment correlated with increased regional brain volume, validating that phenotypes of Chd8 +/ del5 mice overlap pathology reported in humans with CHD8 mutations. We applied network analysis to characterize neurodevelopmental gene expression, revealing widespread transcriptional changes in Chd8 +/ del5 mice across pathways disrupted in neurodevelopmental disorders, including neurogenesis, synaptic processes andmore » neuroimmune signaling. We identified a co-expression module with peak expression in early brain development featuring dysregulation of RNA processing, chromatin remodeling and cell-cycle genes enriched for promoter binding by Chd8, and we validated increased neuronal proliferation and developmental splicing perturbation in Chd8 +/ del5 mice. Finally, this integrative analysis offers an initial picture of the consequences of Chd8 haploinsufficiency for brain development.« less

Bardoxolone methyl (BARD) ameliorates ischemic AKI and increases expression of protective genes Nrf2, PPARγ, and HO-1

PubMed Central

Wu, Qing Qing; Wang, Yanxia; Senitko, Martin; Meyer, Colin; Wigley, W. Christian; Ferguson, Deborah A.; Grossman, Eric; Chen, Jianlin; Zhou, Xin J.; Hartono, John; Winterberg, Pamela; Chen, Bo; Agarwal, Anapam

2011-01-01

Ischemic acute kidney injury (AKI) triggers expression of adaptive (protective) and maladaptive genes. Agents that increase expression of protective genes should provide a therapeutic benefit. We now report that bardoxolone methyl (BARD) ameliorates ischemic murine AKI as assessed by both renal function and pathology. BARD may exert its beneficial effect by increasing expression of genes previously shown to protect against ischemic AKI, NF-E2-related factor 2 (Nrf2), peroxisome proliferator-activated receptor-γ (PPARγ), and heme oxygenase 1 (HO-1). Although we found that BARD alone or ischemia-reperfusion alone increased expression of these genes, the greatest increase occurred after the combination of both ischemia-reperfusion and BARD. BARD had a different mode of action than other agents that regulate PPARγ and Nrf2. Thus we report that BARD regulates PPARγ, not by acting as a ligand but by increasing the amount of PPARγ mRNA and protein. This should increase ligand-independent effects of PPARγ. Similarly, BARD increased Nrf2 mRNA; this increased Nrf2 protein by mechanisms in addition to the prolongation of Nrf2 protein half-life previously reported. Finally, we localized expression of these protective genes after ischemia and BARD treatment. Using double-immunofluorescence staining for CD31 and Nrf2 or PPARγ, we found increased Nrf2 and PPARγ on glomerular endothelia in the cortex; Nrf2 was also present on cortical peritubular capillaries. In contrast, HO-1 was localized to different cells, i.e., tubules and interstitial leukocytes. Although Nrf2-dependent increases in HO-1 have been described, our data suggest that BARD's effects on tubular and leukocyte HO-1 during ischemic AKI may be Nrf2 independent. We also found that BARD ameliorated cisplatin nephrotoxicity. PMID:21289052

Bardoxolone methyl (BARD) ameliorates ischemic AKI and increases expression of protective genes Nrf2, PPARγ, and HO-1.

PubMed

Wu, Qing Qing; Wang, Yanxia; Senitko, Martin; Meyer, Colin; Wigley, W Christian; Ferguson, Deborah A; Grossman, Eric; Chen, Jianlin; Zhou, Xin J; Hartono, John; Winterberg, Pamela; Chen, Bo; Agarwal, Anapam; Lu, Christopher Y

2011-05-01

Ischemic acute kidney injury (AKI) triggers expression of adaptive (protective) and maladaptive genes. Agents that increase expression of protective genes should provide a therapeutic benefit. We now report that bardoxolone methyl (BARD) ameliorates ischemic murine AKI as assessed by both renal function and pathology. BARD may exert its beneficial effect by increasing expression of genes previously shown to protect against ischemic AKI, NF-E2-related factor 2 (Nrf2), peroxisome proliferator-activated receptor-γ (PPARγ), and heme oxygenase 1 (HO-1). Although we found that BARD alone or ischemia-reperfusion alone increased expression of these genes, the greatest increase occurred after the combination of both ischemia-reperfusion and BARD. BARD had a different mode of action than other agents that regulate PPARγ and Nrf2. Thus we report that BARD regulates PPARγ, not by acting as a ligand but by increasing the amount of PPARγ mRNA and protein. This should increase ligand-independent effects of PPARγ. Similarly, BARD increased Nrf2 mRNA; this increased Nrf2 protein by mechanisms in addition to the prolongation of Nrf2 protein half-life previously reported. Finally, we localized expression of these protective genes after ischemia and BARD treatment. Using double-immunofluorescence staining for CD31 and Nrf2 or PPARγ, we found increased Nrf2 and PPARγ on glomerular endothelia in the cortex; Nrf2 was also present on cortical peritubular capillaries. In contrast, HO-1 was localized to different cells, i.e., tubules and interstitial leukocytes. Although Nrf2-dependent increases in HO-1 have been described, our data suggest that BARD's effects on tubular and leukocyte HO-1 during ischemic AKI may be Nrf2 independent. We also found that BARD ameliorated cisplatin nephrotoxicity.

CVD-associated non-coding RNA, ANRIL, modulates expression of atherogenic pathways in VSMC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Congrains, Ada; Kamide, Kei; Katsuya, Tomohiro

Highlights: Black-Right-Pointing-Pointer ANRIL maps in the strongest susceptibility locus for cardiovascular disease. Black-Right-Pointing-Pointer Silencing of ANRIL leads to altered expression of tissue remodeling-related genes. Black-Right-Pointing-Pointer The effects of ANRIL on gene expression are splicing variant specific. Black-Right-Pointing-Pointer ANRIL affects progression of cardiovascular disease by regulating proliferation and apoptosis pathways. -- Abstract: ANRIL is a newly discovered non-coding RNA lying on the strongest genetic susceptibility locus for cardiovascular disease (CVD) in the chromosome 9p21 region. Genome-wide association studies have been linking polymorphisms in this locus with CVD and several other major diseases such as diabetes and cancer. The role of thismore » non-coding RNA in atherosclerosis progression is still poorly understood. In this study, we investigated the implication of ANRIL in the modulation of gene sets directly involved in atherosclerosis. We designed and tested siRNA sequences to selectively target two exons (exon 1 and exon 19) of the transcript and successfully knocked down expression of ANRIL in human aortic vascular smooth muscle cells (HuAoVSMC). We used a pathway-focused RT-PCR array to profile gene expression changes caused by ANRIL knock down. Notably, the genes affected by each of the siRNAs were different, suggesting that different splicing variants of ANRIL might have distinct roles in cell physiology. Our results suggest that ANRIL splicing variants play a role in coordinating tissue remodeling, by modulating the expression of genes involved in cell proliferation, apoptosis, extra-cellular matrix remodeling and inflammatory response to finally impact in the risk of cardiovascular disease and other pathologies.« less

Genome-wide analysis of carotenoid cleavage oxygenase genes and their responses to various phytohormones and abiotic stresses in apple (Malus domestica).

PubMed

Chen, Hongfei; Zuo, Xiya; Shao, Hongxia; Fan, Sheng; Ma, Juanjuan; Zhang, Dong; Zhao, Caiping; Yan, Xiangyan; Liu, Xiaojie; Han, Mingyu

2018-02-01

Carotenoid cleavage oxygenases (CCOs) are able to cleave carotenoids to produce apocarotenoids and their derivatives, which are important for plant growth and development. In this study, 21 apple CCO genes were identified and divided into six groups based on their phylogenetic relationships. We further characterized the apple CCO genes in terms of chromosomal distribution, structure and the presence of cis-elements in the promoter. We also predicted the cellular localization of the encoded proteins. An analysis of the synteny within the apple genome revealed that tandem, segmental, and whole-genome duplication events likely contributed to the expansion of the apple carotenoid oxygenase gene family. An additional integrated synteny analysis identified orthologous carotenoid oxygenase genes between apple and Arabidopsis thaliana, which served as references for the functional analysis of the apple CCO genes. The net photosynthetic rate, transpiration rate, and stomatal conductance of leaves decreased, while leaf stomatal density increased under drought and saline conditions. Tissue-specific gene expression analyses revealed diverse spatiotemporal expression patterns. Finally, hormone and abiotic stress treatments indicated that many apple CCO genes are responsive to various phytohormones as well as drought and salinity stresses. The genome-wide identification of apple CCO genes and the analyses of their expression patterns described herein may provide a solid foundation for future studies examining the regulation and functions of this gene family. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Lipid metabolism in Rhodnius prolixus: Lessons from the genome.

PubMed

Majerowicz, David; Calderón-Fernández, Gustavo M; Alves-Bezerra, Michele; De Paula, Iron F; Cardoso, Lívia S; Juárez, M Patricia; Atella, Georgia C; Gondim, Katia C

2017-01-05

The kissing bug Rhodnius prolixus is both an important vector of Chagas' disease and an interesting model for investigation into the field of physiology, including lipid metabolism. The publication of this insect genome will bring a huge amount of new molecular biology data to be used in future experiments. Although this work represents a promising scenario, a preliminary analysis of the sequence data is necessary to identify and annotate the genes involved in lipid metabolism. Here, we used bioinformatics tools and gene expression analysis to explore genes from different genes families and pathways, including genes for fat breakdown, as lipases and phospholipases, and enzymes from β-oxidation, fatty acid metabolism, and acyl-CoA and glycerolipid synthesis. The R. prolixus genome encodes 31 putative lipase genes, including 21 neutral lipases and 5 acid lipases. The expression profiles of some of these genes were analyzed. We were able to identify nine phospholipase A2 genes. A variety of gene families that participate in fatty acid synthesis and modification were studied, including fatty acid synthase, elongase, desaturase and reductase. Concerning the synthesis of glycerolipids, we found a second isoform of glycerol-3-phosphate acyltransferase that was ubiquitously expressed throughout the organs. Finally, all genes involved in fatty acid β-oxidation were identified, but not a long-chain acyl-CoA dehydrogenase. These results provide fundamental data to be used in future research on insect lipid metabolism and its possible relevance to Chagas' disease transmission. Copyright © 2016 Elsevier B.V. All rights reserved.

Elevation of the Yields of Very Long Chain Polyunsaturated Fatty Acids via Minimal Codon Optimization of Two Key Biosynthetic Enzymes

PubMed Central

Zheng, Desong; Sun, Quanxi; Liu, Jiang; Li, Yaxiao; Hua, Jinping

2016-01-01

Eicosapentaenoic acid (EPA, 20:5Δ5,8,11,14,17) and Docosahexaenoic acid (DHA, 22:6Δ4,7,10,13,16,19) are nutritionally beneficial to human health. Transgenic production of EPA and DHA in oilseed crops by transferring genes originating from lower eukaryotes, such as microalgae and fungi, has been attempted in recent years. However, the low yield of EPA and DHA produced in these transgenic crops is a major hurdle for the commercialization of these transgenics. Many factors can negatively affect transgene expression, leading to a low level of converted fatty acid products. Among these the codon bias between the transgene donor and the host crop is one of the major contributing factors. Therefore, we carried out codon optimization of a fatty acid delta-6 desaturase gene PinD6 from the fungus Phytophthora infestans, and a delta-9 elongase gene, IgASE1 from the microalga Isochrysis galbana for expression in Saccharomyces cerevisiae and Arabidopsis respectively. These are the two key genes encoding enzymes for driving the first catalytic steps in the Δ6 desaturation/Δ6 elongation and the Δ9 elongation/Δ8 desaturation pathways for EPA/DHA biosynthesis. Hence expression levels of these two genes are important in determining the final yield of EPA/DHA. Via PCR-based mutagenesis we optimized the least preferred codons within the first 16 codons at their N-termini, as well as the most biased CGC codons (coding for arginine) within the entire sequences of both genes. An expression study showed that transgenic Arabidopsis plants harbouring the codon-optimized IgASE1 contained 64% more elongated fatty acid products than plants expressing the native IgASE1 sequence, whilst Saccharomyces cerevisiae expressing the codon optimized PinD6 yielded 20 times more desaturated products than yeast expressing wild-type (WT) PinD6. Thus the codon optimization strategy we developed here offers a simple, effective and low-cost alternative to whole gene synthesis for high expression of foreign genes in yeast and Arabidopsis. PMID:27433934

Comprehensive analysis of gene expression patterns in Friedreich's ataxia fibroblasts by RNA sequencing reveals altered levels of protein synthesis factors and solute carriers

PubMed Central

Li, Yanjie; Lu, Yue; Lin, Kevin; Hauser, Lauren A.; Lynch, David R.

2017-01-01

ABSTRACT Friedreich's ataxia (FRDA) is an autosomal recessive neurodegenerative disease usually caused by large homozygous expansions of GAA repeat sequences in intron 1 of the frataxin (FXN) gene. FRDA patients homozygous for GAA expansions have low FXN mRNA and protein levels when compared with heterozygous carriers or healthy controls. Frataxin is a mitochondrial protein involved in iron–sulfur cluster synthesis, and many FRDA phenotypes result from deficiencies in cellular metabolism due to lowered expression of FXN. Presently, there is no effective treatment for FRDA, and biomarkers to measure therapeutic trial outcomes and/or to gauge disease progression are lacking. Peripheral tissues, including blood cells, buccal cells and skin fibroblasts, can readily be isolated from FRDA patients and used to define molecular hallmarks of disease pathogenesis. For instance, FXN mRNA and protein levels as well as FXN GAA-repeat tract lengths are routinely determined using all of these cell types. However, because these tissues are not directly involved in disease pathogenesis, their relevance as models of the molecular aspects of the disease is yet to be decided. Herein, we conducted unbiased RNA sequencing to profile the transcriptomes of fibroblast cell lines derived from 18 FRDA patients and 17 unaffected control individuals. Bioinformatic analyses revealed significantly upregulated expression of genes encoding plasma membrane solute carrier proteins in FRDA fibroblasts. Conversely, the expression of genes encoding accessory factors and enzymes involved in cytoplasmic and mitochondrial protein synthesis was consistently decreased in FRDA fibroblasts. Finally, comparison of genes differentially expressed in FRDA fibroblasts to three previously published gene expression signatures defined for FRDA blood cells showed substantial overlap between the independent datasets, including correspondingly deficient expression of antioxidant defense genes. Together, these results indicate that gene expression profiling of cells derived from peripheral tissues can, in fact, consistently reveal novel molecular pathways of the disease. When performed on statistically meaningful sample group sizes, unbiased global profiling analyses utilizing peripheral tissues are critical for the discovery and validation of FRDA disease biomarkers. PMID:29125828

Alteration of gene expression by zinc oxide nanoparticles or zinc sulfate in vivo and comparison with in vitro data: A harmonious case.

PubMed

Zhang, Wei-Dong; Zhao, Yong; Zhang, Hong-Fu; Wang, Shu-Kun; Hao, Zhi-Hui; Liu, Jing; Yuan, Yu-Qing; Zhang, Peng-Fei; Yang, Hong-Di; Shen, Wei; Li, Lan

2016-08-01

Granulosa cells (GCs) are those somatic cells closest to the female germ cell. GCs play a vital role in oocyte growth and development, and the oocyte is necessary for multiplication of a species. Zinc oxide (ZnO) nanoparticles (NPs) readily cross biologic barriers to be absorbed into biologic systems that make them promising candidates as food additives. The objective of the present investigation was to explore the impact of intact NPs on gene expression and the functional classification of altered genes in hen GCs in vivo, to compare the data from in vivo and in vitro studies, and finally to point out the adverse effects of ZnO NPs on the reproductive system. After a 24-week treatment, hen GCs were isolated and gene expression was quantified. Intact NPs were found in the ovary and other organs. Zn levels were similar in ZnO-NP-100 mg/kg- and ZnSO4-100 mg/kg-treated hen ovaries. ZnO-NP-100 mg/kg and ZnSO4-100 mg/kg regulated the expression of the same sets of genes, and they also altered the expression of different sets of genes individually. The number of genes altered by the ZnO-NP-100 mg/kg and ZnSO4-100 mg/kg treatments was different. Gene Ontology (GO) functional analysis reported that different results for the two treatments and, in Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, 12 pathways (out of the top 20 pathways) in each treatment were different. These results suggested that intact NPs and Zn(2+) had different effects on gene expression in GCs in vivo. In our recent publication, we noted that intact NPs and Zn(2+) differentially altered gene expression in GCs in vitro. However, GO functional classification and KEGG pathway enrichment analyses revealed close similarities for the changed genes in vivo and in vitro after ZnO NP treatment. Furthermore, close similarities were observed for the changed genes after ZnSO4 treatments in vivo and in vitro by GO functional classification and KEGG pathway enrichment analyses. Therefore, the effects of ZnO NPs on gene expression in vitro might represent their effects on gene expression in vivo. The results from this study and our earlier studies support previous findings indicating ZnO NPs promote adverse effects on organisms. Therefore, precautions should be taken when ZnO NPs are used as diet additives for hens because they might cause reproductive issues. Copyright © 2016 Elsevier Inc. All rights reserved.

Assessment of global ischemic/reperfusion and Tacrolimus administration on CA1 region of hippocampus: gene expression profiles of BAX and BCL2 genes.

PubMed

Badr, R; Hashemi, M; Javadi, G; Movafagh, A; Mahdian, R

2016-01-01

It is well known that hippocampus has a pivotal role in learning, formation and consolidation of memory. Global cerebral ischemia causes severe damage to pyramidal neurons of the CA1 region and usually results in residual neurological deficits following a recovery from ischemia. Scientists investigate to find the molecular mechanism of apoptosis and to use this cell death for clinical treatment. In this investigation, we evaluated the molecular mechanism of FK-506 in apoptosis using gene expression quantification of BAX and BCL-2 genes in hippocampus following global ischemic/reperfusion. In the present experimental study, adult male Wistar rats were obtained and housed under standard conditions. Each experimental group consisted of five rats and was equally distributed in the normal control, ischemia/reperfusion, ischemia/reperfusion followed by FK-506. Global ischemia was induced for animals in ischemia and drug groups. In the drug group, moreover, two doses of FK-506 were injected as IV injection and intra-peritoneal (IP) injection after 48 h. Then, hippocampus tissue was removed. Consequently, RNA isolated, cDNA was synthesized and Real-Time PCR was performed. Finally, the obtained data was analyzed statistically (p<0.05). The quantitative results showed the BAX expression ratio increased approximately 3-times in ischemia/reperfusion (3.11 ± 0.28) group compared to the untreated (NR) and the drug group (p<0.001). The statistical analysis showed a significant difference for BCL-2 expression between the experimental groups (p<0.001). The mRNA level of BCL-2 decreased in the ischemia/reperfusion group, while it was without alteration in the other groups. The results showed that global cerebral ischemia/reperfusion induced BAX as pro-apoptotic gene and tacrolimus a neuroprotective drug inhibited BAX gene expression and induced BCL-2 gene expression as anti-apoptotic gene (Tab. 2, Fig. 3, Ref. 21).