Comparative mapping of DNA markers from the familial Alzheimer disease and Down syndrome regions of human chromosome 21 to mouse chromosomes 16 and 17.

PubMed

Cheng, S V; Nadeau, J H; Tanzi, R E; Watkins, P C; Jagadesh, J; Taylor, B A; Haines, J L; Sacchi, N; Gusella, J F

1988-08-01

Mouse trisomy 16 has been proposed as an animal model of Down syndrome (DS), since this chromosome contains homologues of several loci from the q22 band of human chromosome 21. The recent mapping of the defect causing familial Alzheimer disease (FAD) and the locus encoding the Alzheimer amyloid beta precursor protein (APP) to human chromosome 21 has prompted a more detailed examination of the extent of conservation of this linkage group between the two species. Using anonymous DNA probes and cloned genes from human chromosome 21 in a combination of recombinant inbred and interspecific mouse backcross analyses, we have established that the linkage group shared by mouse chromosome 16 includes not only the critical DS region of human chromosome 21 but also the APP gene and FAD-linked markers. Extending from the anonymous DNA locus D21S52 to ETS2, the linkage map of six loci spans 39% recombination in man but only 6.4% recombination in the mouse. A break in synteny occurs distal to ETS2, with the homologue of the human marker D21S56 mapping to mouse chromosome 17. Conservation of the linkage relationships of markers in the FAD region suggests that the murine homologue of the FAD locus probably maps to chromosome 16 and that detailed comparison of the corresponding region in both species could facilitate identification of the primary defect in this disorder. The break in synteny between the terminal portion of human chromosome 21 and mouse chromosome 16 indicates, however, that mouse trisomy 16 may not represent a complete model of DS.

Comparative mapping of DNA markers from the familial Alzheimer disease and Down syndrome regions of human chromosome 21 to mouse chromosomes 16 and 17

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

Cheng, S.V.; Nadeau, J.H.; Tanzi, R.E.

1988-08-01

Mouse trisomy 16 has been proposed as an animal model of Down syndrome (DS), since this chromosome contains homologues of several loci from the q22 band of human chromosome 21. The recent mapping of the defect causing familial Alzheimer disease (FAD) and the locus encoding the Alzheimer amyloid {beta} precursor protein (APP) to human chromosome 21 has prompted a more detailed examination of the extent of conservation of this linkage group between the two species. Using anonymous DNA probes and cloned genes from human chromosome 21 in a combination of recombinant inbred and interspecific mouse backcross analyses, the authors havemore » established that the linkage group shared by mouse chromosome 16 includes not only the critical DS region of human chromosome 21 but also the APP gene and FAD-linked markers. Extending from the anonymous DNA locus D21S52 to ETS2, the linkage map of six loci spans 39% recombination in man but only 6.4% recombination in the mouse. A break in synteny occurs distal to ETS2, with the homologue of the human marker D21S56 mapping to mouse chromosome 17. Conservation of the linkage relationships of markers in the FAD region suggests that the murine homologue of the FAD locus probably maps to chromosome 16 and that detailed comparison of the corresponding region in both species could facilitate identification of the primary defect in this disorder. The break in synteny between the terminal portion of human chromosome 21 and mouse chromosome 16 indicates, however, that mouse trisomy 16 may not represent a complete model of DS.« less

Transcription Factors Encoded on Core and Accessory Chromosomes of Fusarium oxysporum Induce Expression of Effector Genes

PubMed Central

van der Does, H. Charlotte; Schmidt, Sarah M.; Langereis, Léon; Hughes, Timothy R.

2016-01-01

Proteins secreted by pathogens during host colonization largely determine the outcome of pathogen-host interactions and are commonly called ‘effectors’. In fungal plant pathogens, coordinated transcriptional up-regulation of effector genes is a key feature of pathogenesis and effectors are often encoded in genomic regions with distinct repeat content, histone code and rate of evolution. In the tomato pathogen Fusarium oxysporum f. sp. lycopersici (Fol), effector genes reside on one of four accessory chromosomes, known as the ‘pathogenicity’ chromosome, which can be exchanged between strains through horizontal transfer. The three other accessory chromosomes in the Fol reference strain may also be important for virulence towards tomato. Expression of effector genes in Fol is highly up-regulated upon infection and requires Sge1, a transcription factor encoded on the core genome. Interestingly, the pathogenicity chromosome itself contains 13 predicted transcription factor genes and for all except one, there is a homolog on the core genome. We determined DNA binding specificity for nine transcription factors using oligonucleotide arrays. The binding sites for homologous transcription factors were highly similar, suggesting that extensive neofunctionalization of DNA binding specificity has not occurred. Several DNA binding sites are enriched on accessory chromosomes, and expression of FTF1, its core homolog FTF2 and SGE1 from a constitutive promoter can induce expression of effector genes. The DNA binding sites of only these three transcription factors are enriched among genes up-regulated during infection. We further show that Ftf1, Ftf2 and Sge1 can activate transcription from their binding sites in yeast. RNAseq analysis revealed that in strains with constitutive expression of FTF1, FTF2 or SGE1, expression of a similar set of plant-responsive genes on the pathogenicity chromosome is induced, including most effector genes. We conclude that the Fol pathogenicity chromosome may be partially transcriptionally autonomous, but there are also extensive transcriptional connections between core and accessory chromosomes. PMID:27855160

Chromosomal localization and cDNA cloning of the human DBP and TEF genes

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

Khatib, Z.A.; Inaba, T.; Valentine, M.

1994-09-15

The authors have isolated cDNA and genomic clones and determined the human chromosome positions of two genes encoding transcription factors expressed in the liver and the pituitary gland: albumin D-site-binding protein (DBP) and thyrotroph embryonic factor (TEF). Both proteins have been identified as members of the PAR (proline and acidic amino acid-rich) subfamily of bZIP transcription factors in the rat, but human homologues have not been characterized. Using a fluorescence in situ hybridization technique, the DBP locus was assigned to chromosome 19q13, and TEF to chromosome 22q13. Each assignment was confirmed by means of human chromosome segregation in somatic cellmore » hybrids. Coding sequences of DBP and TEF, extending beyond the bZIP domain to the PAR region, were highly conserved in both human-human and interspecies comparisons. Conservation of the exon-intron boundaries of each bZIP domain-encoding exon suggested derivation from a common ancestral gene. DBP and TEF mRNAs were expressed in all tissues and cell lines examined, including brain, lung, liver, spleen, and kidney. Knowledge of the human chromosome locations of these PAR proteins will facilitate studies to assess their involvement in carcinogenesis and other fundamental biological processes. 37 refs., 5 figs., 1 tab.« less

Cloning, structure, and chromosome localization of the mouse glutaryl-CoA dehydrogenase gene

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

Koeller, D.M.; DiGiulio, A.; Frerman, F.E.

Glutaryl-CoA dehydrogenase (GCDH) is a nuclear-encoded, mitochondrial matrix enzyme. In humans, deficiency of GCDH leads to glutaric acidemia type I, and inherited disorder of amino acid metabolism characterized by a progressive neurodegenerative disease. In this report we describe the cloning and structure of the mouse GCDH (Gcdh) gene and cDNA and its chromosomal localization. The mouse Gcdh cDNA is 1.75 kb long and contains and open reading frame of 438 amino acids. The amino acid sequences of mouse, human, and pig GCDH are highly conserved. The mouse Gcdh gene contains 11 exons and spans 7 kb of genomic DNA. Gcdhmore » was mapped by backcross analysis to mouse chromosome 8 within a region that is homologous to a region of human chromosome 19, where the human gene was previously mapped. 14 refs., 3 figs.« less

Identification of the sex genes in an early diverged fungus.

PubMed

Idnurm, Alexander; Walton, Felicia J; Floyd, Anna; Heitman, Joseph

2008-01-10

Sex determination in fungi is controlled by a small, specialized region of the genome in contrast to the large sex-specific chromosomes of animals and some plants. Different gene combinations reside at these mating-type (MAT) loci and confer sexual identity; invariably they encode homeodomain, alpha-box, or high mobility group (HMG)-domain transcription factors. So far, MAT loci have been characterized from a single monophyletic clade of fungi, the Dikarya (the ascomycetes and basidiomycetes), and the ancestral state and evolutionary history of these loci have remained a mystery. Mating in the basal members of the kingdom has been less well studied, and even their precise taxonomic inter-relationships are still obscure. Here we apply bioinformatic and genetic mapping to identify the sex-determining (sex) region in Phycomyces blakesleeanus (Zygomycota), which represents an early branch within the fungi. Each sex allele contains a single gene that encodes an HMG-domain protein, implicating the HMG-domain proteins as an earlier form of fungal MAT loci. Additionally, one allele also contains a copy of a unique, chromosome-specific repetitive element, suggesting a generalized mechanism for the earliest steps in the evolution of sex determination and sex chromosome structure in eukaryotes.

Allelic Variation on Murine Chromosome 11 Modifies Host Inflammatory Responses and Resistance to Bacillus anthracis

PubMed Central

Terra, Jill K.; France, Bryan; Cote, Christopher K.; Jenkins, Amy; Bozue, Joel A.; Welkos, Susan L.; Bhargava, Ragini; Ho, Chi-Lee; Mehrabian, Margarete; Pan, Calvin; Lusis, Aldons J.; Davis, Richard C.; LeVine, Steven M.; Bradley, Kenneth A.

2011-01-01

Anthrax is a potentially fatal disease resulting from infection with Bacillus anthracis. The outcome of infection is influenced by pathogen-encoded virulence factors such as lethal toxin (LT), as well as by genetic variation within the host. To identify host genes controlling susceptibility to anthrax, a library of congenic mice consisting of strains with homozygous chromosomal segments from the LT-responsive CAST/Ei strain introgressed on a LT-resistant C57BL/6 (B6) background was screened for response to LT. Three congenic strains containing CAST/Ei regions of chromosome 11 were identified that displayed a rapid inflammatory response to LT similar to, but more severe than that driven by a LT-responsive allele of the inflammasome constituent NRLP1B. Importantly, increased response to LT in congenic mice correlated with greater resistance to infection by the Sterne strain of B. anthracis. The genomic region controlling the inflammatory response to LT was mapped to 66.36–74.67 Mb on chromosome 11, a region that encodes the LT-responsive CAST/Ei allele of Nlrp1b. However, known downstream effects of NLRP1B activation, including macrophage pyroptosis, cytokine release, and leukocyte infiltration could not fully explain the response to LT or the resistance to B. anthracis Sterne in congenic mice. Further, the exacerbated response in congenic mice is inherited in a recessive manner while the Nlrp1b-mediated response to LT is dominant. Finally, congenic mice displayed increased responsiveness in a model of sepsis compared with B6 mice. In total, these data suggest that allelic variation of one or more chromosome 11 genes in addition to Nlrp1b controls the severity of host response to multiple inflammatory stimuli and contributes to resistance to B. anthracis Sterne. Expression quantitative trait locus analysis revealed 25 genes within this region as high priority candidates for contributing to the host response to LT. PMID:22241984

Deletion of Brca2 exon 27 causes hypersensitivity to DNA crosslinks, chromosomal instability, and reduced life span in mice

NASA Technical Reports Server (NTRS)

Donoho, Greg; Brenneman, Mark A.; Cui, Tracy X.; Donoviel, Dorit; Vogel, Hannes; Goodwin, Edwin H.; Chen, David J.; Hasty, Paul

2003-01-01

The Brca2 tumor-suppressor gene contributes to genomic stability, at least in part by a role in homologous recombinational repair. BRCA2 protein is presumed to function in homologous recombination through interactions with RAD51. Both exons 11 and 27 of Brca2 code for domains that interact with RAD51; exon 11 encodes eight BRC motifs, whereas exon 27 encodes a single, distinct interaction domain. Deletion of all RAD51-interacting domains causes embryonic lethality in mice. A less severe phenotype is seen with BRAC2 truncations that preserve some, but not all, of the BRC motifs. These mice can survive beyond weaning, but are runted and infertile, and die very young from cancer. Cells from such mice show hypersensitivity to some genotoxic agents and chromosomal instability. Here, we have analyzed mice and cells with a deletion of only the RAD51-interacting region encoded by exon 27. Mice homozygous for this mutation (called brca2(lex1)) have a shorter life span than that of control littermates, possibly because of early onsets of cancer and sepsis. No other phenotype was observed in these animals; therefore, the brca2(lex1) mutation is less severe than truncations that delete some BRC motifs. However, at the cellular level, the brca2(lex1) mutation causes reduced viability, hypersensitivity to the DNA interstrand crosslinking agent mitomycin C, and gross chromosomal instability, much like more severe truncations. Thus, the extreme carboxy-terminal region encoded by exon 27 is important for BRCA2 function, probably because it is required for a fully functional interaction between BRCA2 and RAD51. Copyright 2003 Wiley-Liss, Inc.

Two circular chromosomes of unequal copy number make up the mitochondrial genome of the rotifer Brachionus plicatilis.

PubMed

Suga, Koushirou; Mark Welch, David B; Tanaka, Yukari; Sakakura, Yoshitaka; Hagiwara, Atsushi

2008-06-01

The monogonont rotifer Brachionus plicatilis is an emerging model system for a diverse array of questions in limnological ecosystem dynamics, the evolution of sexual recombination, cryptic speciation, and the phylogeny of basal metazoans. We sequenced the complete mitochondrial genome of B. plicatilis sensu strictu NH1L and found that it is composed of 2 circular chromosomes, designated mtDNA-I (11,153 bp) and mtDNA-II (12,672 bp). Hybridization to DNA isolated from mitochondria demonstrated that mtDNA-I is present at 4 times the copy number of mtDNA-II. The only nucleotide similarity between the 2 chromosomes is a 4.9-kbp region of 99.5% identity including a transfer RNA (tRNA) gene and an extensive noncoding region that contains putative D-loop and control sequence. The mtDNA-I chromosome encodes 4 proteins (ATP6, COB, NAD1, and NAD2), 13 tRNAs, and the large and small subunit ribosomal RNAs; mtDNA-II encodes 8 proteins (COX1-3, NAD3-6, and NAD4L) and 9 tRNAs. Gene order is not conserved between B. plicatilis and its closest relative with a sequenced mitochondrial genome, the acanthocephalan Leptorhynchoides thecatus, or other sequenced mitochondrial genomes. Polymerase chain reaction assays and Southern hybridization to DNA from 18 strains of Brachionus suggest that the 2-chromosome structure has been stable for millions of years. The novel organization of the B. plicatilis mitochondrial genome into 2 nearly equal chromosomes of 4-fold different copy number may provide insight into the evolution of metazoan mitochondria and the phylogenetics of rotifers and other basal animal phyla.

Genes controlling seed dormancy and pre-harvest sprouting in a rice-wheat-barley comparison.

PubMed

Li, Chengdao; Ni, Peixiang; Francki, Michael; Hunter, Adam; Zhang, Yong; Schibeci, David; Li, Heng; Tarr, Allen; Wang, Jun; Cakir, Mehmet; Yu, Jun; Bellgard, Matthew; Lance, Reg; Appels, Rudi

2004-05-01

Pre-harvest sprouting results in significant economic loss for the grain industry around the world. Lack of adequate seed dormancy is the major reason for pre-harvest sprouting in the field under wet weather conditions. Although this trait is governed by multiple genes it is also highly heritable. A major QTL controlling both pre-harvest sprouting and seed dormancy has been identified on the long arm of barley chromosome 5H, and it explains over 70% of the phenotypic variation. Comparative genomics approaches among barley, wheat and rice were used to identify candidate gene(s) controlling seed dormancy and hence one aspect of pre-harvest sprouting. The barley seed dormancy/pre-harvest sprouting QTL was located in a region that showed good synteny with the terminal end of the long arm of rice chromosome 3. The rice DNA sequences were annotated and a gene encoding GA20-oxidase was identified as a candidate gene controlling the seed dormancy/pre-harvest sprouting QTL on 5HL. This chromosomal region also shared synteny with the telomere region of wheat chromosome 4AL, but was located outside of the QTL reported for seed dormancy in wheat. The wheat chromosome 4AL QTL region for seed dormancy was syntenic to both rice chromosome 3 and 11. In both cases, corresponding QTLs for seed dormancy have been mapped in rice.

Distribution and Evolution of Yersinia Leucine-Rich Repeat Proteins

PubMed Central

Hu, Yueming; Huang, He; Hui, Xinjie; Cheng, Xi; White, Aaron P.

2016-01-01

Leucine-rich repeat (LRR) proteins are widely distributed in bacteria, playing important roles in various protein-protein interaction processes. In Yersinia, the well-characterized type III secreted effector YopM also belongs to the LRR protein family and is encoded by virulence plasmids. However, little has been known about other LRR members encoded by Yersinia genomes or their evolution. In this study, the Yersinia LRR proteins were comprehensively screened, categorized, and compared. The LRR proteins encoded by chromosomes (LRR1 proteins) appeared to be more similar to each other and different from those encoded by plasmids (LRR2 proteins) with regard to repeat-unit length, amino acid composition profile, and gene expression regulation circuits. LRR1 proteins were also different from LRR2 proteins in that the LRR1 proteins contained an E3 ligase domain (NEL domain) in the C-terminal region or an NEL domain-encoding nucleotide relic in flanking genomic sequences. The LRR1 protein-encoding genes (LRR1 genes) varied dramatically and were categorized into 4 subgroups (a to d), with the LRR1a to -c genes evolving from the same ancestor and LRR1d genes evolving from another ancestor. The consensus and ancestor repeat-unit sequences were inferred for different LRR1 protein subgroups by use of a maximum parsimony modeling strategy. Structural modeling disclosed very similar repeat-unit structures between LRR1 and LRR2 proteins despite the different unit lengths and amino acid compositions. Structural constraints may serve as the driving force to explain the observed mutations in the LRR regions. This study suggests that there may be functional variation and lays the foundation for future experiments investigating the functions of the chromosomally encoded LRR proteins of Yersinia. PMID:27217422

Genetic analysis of chromosomal operons involved in degradation of aromatic hydrocarbons in Pseudomonas putida TMB

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

Polissi, A.; Bestetti, G.; Bertoni, G.

1990-11-01

The catabolic pathway for the degradation of aromatic hydrocarbons encoded by Pseudomonas putida TMB differs from the TOL plasmid-encoded pathway as far as regulation of the upper pathway is concerned. We found, by analyzing Tn5-induced mutants and by Southern blot hybridization with appropriate probes derived from the TOL plasmid pWWO, that the catabolic genes of strain TMB were located on the bacterial chromosome and not on the 84-kb plasmid harbored by this strain. The catabolic genes of TMB and pWWO had sequence homology, as shown by Southern blot hybridization, but different significantly in their restriction patterns. The analysis of themore » mutants suggests that a regulatory mechanism similar to that present in pWWO coexists in TMB with a second mode of regulation which is epistatic on the former and that the chromosomal region carrying the catabolic genes is prone to rearrangements and deletions.« less

Primary structure, expression and chromosomal locus of a human homolog of rat ERK3.

PubMed

Meloche, S; Beatty, B G; Pellerin, J

1996-10-03

We report the cloning and characterization of a human cDNA encoding a novel homolog of rat extracellular signal-regulated kinase 3 (ERK3). The cDNA encodes a predicted protein of 721 amino acids which shares 92% amino acid identity with rat ERK3 over their shared length. Interestingly, the human protein contains a unique extension of 178 amino acids at its carboxy terminal extremity. The human ERK3 protein also displays various degrees of homology to other members of the MAP kinases family, but does not contain the typical TXY regulatory motif between subdomains VII and VIII. Northern blot analysis revealed that ERK3 mRNA is widely distributed in human tissues, with the highest expression detected in skeletal muscle. The human ERK3 gene was mapped by fluorescence in situ hybridization to chromosome 15q21, a region associated with chromosomal abnormalities in acute nonlymphoblastic leukemias. This information should prove valuable in designing studies to define the cellular function of the ERK3 protein kinase.

A high-resolution genetic, physical, and comparative gene map of the doublefoot (Dbf) region of mouse chromosome 1 and the region of conserved synteny on human chromosome 2q35.

PubMed

Hayes, C; Rump, A; Cadman, M R; Harrison, M; Evans, E P; Lyon, M F; Morriss-Kay, G M; Rosenthal, A; Brown, S D

2001-12-01

The mouse doublefoot (Dbf) mutant exhibits preaxial polydactyly in association with craniofacial defects. This mutation has previously been mapped to mouse chromosome 1. We have used a positional cloning strategy, coupled with a comparative sequencing approach using available human draft sequence, to identify putative candidates for the Dbf gene in the mouse and in homologous human region. We have constructed a high-resolution genetic map of the region, localizing the mutation to a 0.4-cM (+/-0.0061) interval on mouse chromosome 1. Furthermore, we have constructed contiguous BAC/PAC clone maps across the mouse and human Dbf region. Using existing markers and additional sequence tagged sites, which we have generated, we have anchored the physical map to the genetic map. Through the comparative sequencing of these clones we have identified 35 genes within this interval, indicating that the region is gene-rich. From this we have identified several genes that are known to be differentially expressed in the developing mid-gestation mouse embryo, some in the developing embryonic limb buds. These genes include those encoding known developmental signaling molecules such as WNT proteins and IHH, and we provide evidence that these genes are candidates for the Dbf mutation.

A septal chromosome segregator protein evolved into a conjugative DNA-translocator protein

PubMed Central

Sepulveda, Edgardo; Vogelmann, Jutta

2011-01-01

Streptomycetes, Gram-positive soil bacteria well known for the production of antibiotics feature a unique conjugative DNA transfer system. In contrast to classical conjugation which is characterized by the secretion of a pilot protein covalently linked to a single-stranded DNA molecule, in Streptomyces a double-stranded DNA molecule is translocated during conjugative transfer. This transfer involves a single plasmid encoded protein, TraB. A detailed biochemical and biophysical characterization of TraB, revealed a close relationship to FtsK, mediating chromosome segregation during bacterial cell division. TraB translocates plasmid DNA by recognizing 8-bp direct repeats located in a specific plasmid region clt. Similar sequences accidentally also occur on chromosomes and have been shown to be bound by TraB. We suggest that TraB mobilizes chromosomal genes by the interaction with these chromosomal clt-like sequences not relying on the integration of the conjugative plasmid into the chromosome. PMID:22479692

Haplotypes in the gene encoding protein kinase c-beta (PRKCB1) on chromosome 16 are associated with autism.

PubMed

Philippi, A; Roschmann, E; Tores, F; Lindenbaum, P; Benajou, A; Germain-Leclerc, L; Marcaillou, C; Fontaine, K; Vanpeene, M; Roy, S; Maillard, S; Decaulne, V; Saraiva, J P; Brooks, P; Rousseau, F; Hager, J

2005-10-01

Autism is a developmental disorder characterized by impairments in social interaction and communication associated with repetitive patterns of interest or behavior. Autism is highly influenced by genetic factors. Genome-wide linkage and candidate gene association approaches have been used to try and identify autism genes. A few loci have repeatedly been reported linked to autism. Several groups reported evidence for linkage to a region on chromosome 16p. We have applied a direct physical identity-by-descent (IBD) mapping approach to perform a high-density (0.85 megabases) genome-wide linkage scan in 116 families from the AGRE collection. Our results confirm linkage to a region on chromosome 16p with autism. High-resolution single-nucleotide polymorphism (SNP) genotyping and analysis of this region show that haplotypes in the protein kinase c-beta gene are strongly associated with autism. An independent replication of the association in a second set of 167 trio families with autism confirmed our initial findings. Overall, our data provide evidence that the PRKCB1 gene on chromosome 16p may be involved in the etiology of autism.

Characterization of the human SDHD gene encoding the small subunit of cytochrome b (cybS) in mitochondrial succinate-ubiquinone oxidoreductase.

PubMed

Hirawake, H; Taniwaki, M; Tamura, A; Amino, H; Tomitsuka, E; Kita, K

1999-08-04

We have mapped large (cybL) and small (cybS) subunits of cytochrome b in the succinate-ubiquinone oxidoreductase (complex II) of human mitochondria to chromosome 1q21 and 11q23, respectively (H. Hirawake et al., Cytogenet. Cell Genet. 79 (1997) 132-138). In the present study, the human SDHD gene encoding cybS was cloned and characterized. The gene comprises four exons and three introns extending over 19 kb. Sequence analysis of the 5' promoter region showed several motifs for the binding of transcription factors including nuclear respiratory factors NRF-1 and NRF-2 at positions -137 and -104, respectively. In addition to this gene, six pseudogenes of cybS were isolated and mapped on the chromosome.

Rat chromosome 1: regional localization of seven genes (Slc9a3, Srd5a1, Esr, Tcp1, Grik5, Tnnt3, Jak2) and anchoring of the genetic linkage map to the cytogenetic map.

PubMed

Szpirer, C; Szpirer, J; Tissir, F; Stephanova, E; Vanvooren, P; Kurtz, T W; Iwai, N; Inagami, T; Pravenec, M; Kren, V; Klinga-Levan, K; Levan, G

1997-09-01

Seven genes were regionally localized on rat Chromosome (Chr) 1, from 1p11 to 1q42, and two of these genes were also included in a linkage map. This mapping work integrates the genetic linkage map and the cytogenetic map, and allows us to orient the linkage map with respect to the centromere, and to deduce the approximate position of the centromere in the linkage map. These mapping data also indicate that the Slc9a3 gene, encoding the Na+/H+ exchanger 3, is an unlikely candidate for the blood pressure loci assigned to rat Chr 1. These new localizations expand comparative mapping between rat Chr 1 and mouse or human chromosomes.

Mutation analysis of the chromosome 14q24.3 dihydrolipoyl succinyltransferase (DLST) gene in patients with early-onset Alzheimer disease.

PubMed

Cruts, M; Backhovens, H; Van Gassen, G; Theuns, J; Wang, S Y; Wehnert, A; van Duijn, C M; Karlsson, T; Hofman, A; Adolfsson, R

1995-10-13

Linkage analysis studies have indicated that the chromosome band 14q24.3 harbours a major gene for familial early-onset Alzheimer's disease (AD). Recently we localized the chromosome 14 AD gene (AD3) in the 6.4 cM interval between the markers D14S289 and D14S61. We mapped the gene encoding dihydrolipoyl succinyltransferase (DLST), the E2k component of human alpha-ketoglutarate dehydrogenase complex (KGDHC), in the AD3 candidate region using yeast artificial chromosomes (YACs). The DLST gene is a candidate for the AD3 gene since deficiencies in KGDHC activity have been observed in brain tissue and fibroblasts of AD patients. The 15 exons and the promoter region of the DLST gene were analysed for mutations in chromosome 14 linked AD cases and in two series of unrelated early-onset AD cases (onset age < 55 years). Sequence variations in intronic sequences (introns 3, 5 and 10) or silent mutations in exonic sequences (exons 8 and 14) were identified. However, no AD related mutations were observed, suggesting that the DLST gene is not the chromosome 14 AD3 gene.

Genome-Wide Analysis in Three Fusarium Pathogens Identifies Rapidly Evolving Chromosomes and Genes Associated with Pathogenicity

PubMed Central

Sperschneider, Jana; Gardiner, Donald M.; Thatcher, Louise F.; Lyons, Rebecca; Singh, Karam B.; Manners, John M.; Taylor, Jennifer M.

2015-01-01

Pathogens and hosts are in an ongoing arms race and genes involved in host–pathogen interactions are likely to undergo diversifying selection. Fusarium plant pathogens have evolved diverse infection strategies, but how they interact with their hosts in the biotrophic infection stage remains puzzling. To address this, we analyzed the genomes of three Fusarium plant pathogens for genes that are under diversifying selection. We found a two-speed genome structure both on the chromosome and gene group level. Diversifying selection acts strongly on the dispensable chromosomes in Fusarium oxysporum f. sp. lycopersici and on distinct core chromosome regions in Fusarium graminearum, all of which have associations with virulence. Members of two gene groups evolve rapidly, namely those that encode proteins with an N-terminal [SG]-P-C-[KR]-P sequence motif and proteins that are conserved predominantly in pathogens. Specifically, 29 F. graminearum genes are rapidly evolving, in planta induced and encode secreted proteins, strongly pointing toward effector function. In summary, diversifying selection in Fusarium is strongly reflected as genomic footprints and can be used to predict a small gene set likely to be involved in host–pathogen interactions for experimental verification. PMID:25994930

The major resistance gene cluster in lettuce is highly duplicated and spans several megabases.

PubMed Central

Meyers, B C; Chin, D B; Shen, K A; Sivaramakrishnan, S; Lavelle, D O; Zhang, Z; Michelmore, R W

1998-01-01

At least 10 Dm genes conferring resistance to the oomycete downy mildew fungus Bremia lactucae map to the major resistance cluster in lettuce. We investigated the structure of this cluster in the lettuce cultivar Diana, which contains Dm3. A deletion breakpoint map of the chromosomal region flanking Dm3 was saturated with a variety of molecular markers. Several of these markers are components of a family of resistance gene candidates (RGC2) that encode a nucleotide binding site and a leucine-rich repeat region. These motifs are characteristic of plant disease resistance genes. Bacterial artificial chromosome clones were identified by using duplicated restriction fragment length polymorphism markers from the region, including the nucleotide binding site-encoding region of RGC2. Twenty-two distinct members of the RGC2 family were characterized from the bacterial artificial chromosomes; at least two additional family members exist. The RGC2 family is highly divergent; the nucleotide identity was as low as 53% between the most distantly related copies. These RGC2 genes span at least 3.5 Mb. Eighteen members were mapped on the deletion breakpoint map. A comparison between the phylogenetic and physical relationships of these sequences demonstrated that closely related copies are physically separated from one another and indicated that complex rearrangements have shaped this region. Analysis of low-copy genomic sequences detected no genes, including RGC2, in the Dm3 region, other than sequences related to retrotransposons and transposable elements. The related but divergent family of RGC2 genes may act as a resource for the generation of new resistance phenotypes through infrequent recombination or unequal crossing over. PMID:9811791

Chromosome-encoded beta-lactamases of Citrobacter diversus. Interaction with beta-iodopenicillanate and labelling of the active site.

PubMed Central

Amicosante, G; Oratore, A; Joris, B; Galleni, M; Frère, J M; Van Beeumen, J

1988-01-01

Both forms of the chromosome-encoded beta-lactamase of Citrobacter diversus react with beta-iodopenicillanate at a rate characteristic of class A beta-lactamases. The active site of form I was labelled with the same reagent. The sequence of the peptide obtained after trypsin hydrolysis is identical with that of a peptide obtained in a similar manner from the chromosome-encoded beta-lactamase of Klebsiella pneumoniae. PMID:2848500

Dystonia gene in Ashkenazi Jewish population is located on chromosome 9q32-34.

PubMed

Kramer, P L; de Leon, D; Ozelius, L; Risch, N; Bressman, S B; Brin, M F; Schuback, D E; Burke, R E; Kwiatkowski, D J; Shale, H

1990-02-01

Idiopathic torsion dystonia (ITD) is a neurological disorder characterized by sustained muscle contractions that appear as twisting movements of the limbs, trunk, and/or neck, which can progress to abnormal postures. Most familial forms of ITD follow autosomal dominant transmission with reduced penetrance. The frequency of ITD in the Ashkenazi Jewish population is five to ten times greater than that in other groups. Recently, a gene for ITD (DYT1) in a non-Jewish kindred was located on chromosome 9q32-34, with tight linkage to the gene encoding gelsolin (GSN). In the present study linkage analysis using DNA polymorphisms is used to locate a gene responsible for susceptibility to ITD in 12 Ashkenazi Jewish families. This dystonia gene exhibits close linkage with the gene encoding argininosuccinate synthetase (ASS), and appears by multipoint analysis to lie in the q32-34 region of chromosome 9, a region that also contains the loci for gelsolin and dopamine-beta-hydroxylase. The same gene may be responsible for ITD both in the non-Jewish kindred mentioned above and in the Ashkenazi Jewish families presented here. However, because there is substantial difference between the penetrance of the dominant allele in these two groups, two different mutations may be operating to produce susceptibility to this disease in the two groups.

Ribosomal DNA status inferred from DNA cloud assays and mass spectrometry identification of agarose-squeezed proteins interacting with chromatin (ASPIC-MS).

PubMed

Krol, Kamil; Jendrysek, Justyna; Debski, Janusz; Skoneczny, Marek; Kurlandzka, Anna; Kaminska, Joanna; Dadlez, Michal; Skoneczna, Adrianna

2017-04-11

Ribosomal RNA-encoding genes (rDNA) are the most abundant genes in eukaryotic genomes. To meet the high demand for rRNA, rDNA genes are present in multiple tandem repeats clustered on a single or several chromosomes and are vastly transcribed. To facilitate intensive transcription and prevent rDNA destabilization, the rDNA-encoding portion of the chromosome is confined in the nucleolus. However, the rDNA region is susceptible to recombination and DNA damage, accumulating mutations, rearrangements and atypical DNA structures. Various sophisticated techniques have been applied to detect these abnormalities. Here, we present a simple method for the evaluation of the activity and integrity of an rDNA region called a "DNA cloud assay". We verified the efficacy of this method using yeast mutants lacking genes important for nucleolus function and maintenance (RAD52, SGS1, RRM3, PIF1, FOB1 and RPA12). The DNA cloud assay permits the evaluation of nucleolus status and is compatible with downstream analyses, such as the chromosome comet assay to identify DNA structures present in the cloud and mass spectrometry of agarose squeezed proteins (ASPIC-MS) to detect nucleolar DNA-bound proteins, including Las17, the homolog of human Wiskott-Aldrich Syndrome Protein (WASP).

Ribosomal DNA status inferred from DNA cloud assays and mass spectrometry identification of agarose-squeezed proteins interacting with chromatin (ASPIC-MS)

PubMed Central

Krol, Kamil; Jendrysek, Justyna; Debski, Janusz; Skoneczny, Marek; Kurlandzka, Anna; Kaminska, Joanna; Dadlez, Michal; Skoneczna, Adrianna

2017-01-01

Ribosomal RNA-encoding genes (rDNA) are the most abundant genes in eukaryotic genomes. To meet the high demand for rRNA, rDNA genes are present in multiple tandem repeats clustered on a single or several chromosomes and are vastly transcribed. To facilitate intensive transcription and prevent rDNA destabilization, the rDNA-encoding portion of the chromosome is confined in the nucleolus. However, the rDNA region is susceptible to recombination and DNA damage, accumulating mutations, rearrangements and atypical DNA structures. Various sophisticated techniques have been applied to detect these abnormalities. Here, we present a simple method for the evaluation of the activity and integrity of an rDNA region called a “DNA cloud assay”. We verified the efficacy of this method using yeast mutants lacking genes important for nucleolus function and maintenance (RAD52, SGS1, RRM3, PIF1, FOB1 and RPA12). The DNA cloud assay permits the evaluation of nucleolus status and is compatible with downstream analyses, such as the chromosome comet assay to identify DNA structures present in the cloud and mass spectrometry of agarose squeezed proteins (ASPIC-MS) to detect nucleolar DNA-bound proteins, including Las17, the homolog of human Wiskott-Aldrich Syndrome Protein (WASP). PMID:28212567

X chromosome inactivation in a female carrier of a 1.28 Mb deletion encompassing the human X inactivation centre.

PubMed

de Hoon, B; Splinter, Erik; Eussen, B; Douben, J C W; Rentmeester, E; van de Heijning, M; Laven, J S E; de Klein, J E M M; Liebelt, J; Gribnau, J

2017-11-05

X chromosome inactivation (XCI) is a mechanism specifically initiated in female cells to silence one X chromosome, thereby equalizing the dose of X-linked gene products between male and female cells. XCI is regulated by a locus on the X chromosome termed the X-inactivation centre (XIC). Located within the XIC is XIST , which acts as a master regulator of XCI. During XCI, XIST is upregulated on the inactive X chromosome and chromosome-wide cis spreading of XIST leads to inactivation. In mouse, the Xic comprises Xist and all cis -regulatory elements and genes involved in Xist regulation. The activity of the XIC is regulated by trans -acting factors located elsewhere in the genome: X-encoded XCI activators positively regulating XCI, and autosomally encoded XCI inhibitors providing the threshold for XCI initiation. Whether human XCI is regulated through a similar mechanism, involving trans -regulatory factors acting on the XIC has remained elusive so far. Here, we describe a female individual with ovarian dysgenesis and a small X chromosomal deletion of the XIC. SNP-array and targeted locus amplification (TLA) analysis defined the deletion to a 1.28 megabase region, including XIST and all elements and genes that perform cis -regulatory functions in mouse XCI. Cells carrying this deletion still initiate XCI on the unaffected X chromosome, indicating that XCI can be initiated in the presence of only one XIC. Our results indicate that the trans -acting factors required for XCI initiation are located outside the deletion, providing evidence that the regulatory mechanisms of XCI are conserved between mouse and human.This article is part of the themed issue 'X-chromosome inactivation: a tribute to Mary Lyon'. © 2017 The Authors.

Fluorescent in situ hybridization shows DIPLOSPOROUS located on one of the NOR chromosomes in apomictic dandelions (Taraxacum) in the absence of a large hemizygous chromosomal region.

PubMed

Vašut, Radim J; Vijverberg, Kitty; van Dijk, Peter J; de Jong, Hans

2014-11-01

Apomixis in dandelions (Taraxacum: Asteraceae) is encoded by two unlinked dominant loci and a third yet undefined genetic factor: diplosporous omission of meiosis (DIPLOSPOROUS, DIP), parthenogenetic embryo development (PARTHENOGENESIS, PAR), and autonomous endosperm formation, respectively. In this study, we determined the chromosomal position of the DIP locus in Taraxacum by using fluorescent in situ hybridization (FISH) with bacterial artificial chromosomes (BACs) that genetically map within 1.2-0.2 cM of DIP. The BACs showed dispersed fluorescent signals, except for S4-BAC 83 that displayed strong unique signals as well. Under stringent blocking of repeats by C0t-DNA fragments, only a few fluorescent foci restricted to defined chromosome regions remained, including one on the nucleolus organizer region (NOR) chromosomes that contains the 45S rDNAs. FISH with S4-BAC 83 alone and optimal blocking showed discrete foci in the middle of the long arm of one of the NOR chromosomes only in triploid and tetraploid diplosporous dandelions, while signals in sexual diploids were lacking. This agrees with the genetic model of a single dose, dominant DIP allele, absent in sexuals. The length of the DIP region is estimated to cover a region of 1-10 Mb. FISH in various accessions of Taraxacum and the apomictic sister species Chondrilla juncea, confirmed the chromosomal position of DIP within Taraxacum but not outside the genus. Our results endorse that, compared to other model apomictic species, expressing either diplospory or apospory, the genome of Taraxacum shows a more similar and less diverged chromosome structure at the DIP locus. The different levels of allele sequence divergence at apomeiosis loci may reflect different terms of asexual reproduction. The association of apomeiosis loci with repetitiveness, dispersed repeats, and retrotransposons commonly observed in apomictic species may imply a functional role of these shared features in apomictic reproduction, as is discussed.

The Impact of Recombination Hotspots on Genome Evolution of a Fungal Plant Pathogen

PubMed Central

Croll, Daniel; Lendenmann, Mark H.; Stewart, Ethan; McDonald, Bruce A.

2015-01-01

Recombination has an impact on genome evolution by maintaining chromosomal integrity, affecting the efficacy of selection, and increasing genetic variability in populations. Recombination rates are a key determinant of the coevolutionary dynamics between hosts and their pathogens. Historic recombination events created devastating new pathogens, but the impact of ongoing recombination in sexual pathogens is poorly understood. Many fungal pathogens of plants undergo regular sexual cycles, and sex is considered to be a major factor contributing to virulence. We generated a recombination map at kilobase-scale resolution for the haploid plant pathogenic fungus Zymoseptoria tritici. To account for intraspecific variation in recombination rates, we constructed genetic maps from two independent crosses. We localized a total of 10,287 crossover events in 441 progeny and found that recombination rates were highly heterogeneous within and among chromosomes. Recombination rates on large chromosomes were inversely correlated with chromosome length. Short accessory chromosomes often lacked evidence for crossovers between parental chromosomes. Recombination was concentrated in narrow hotspots that were preferentially located close to telomeres. Hotspots were only partially conserved between the two crosses, suggesting that hotspots are short-lived and may vary according to genomic background. Genes located in hotspot regions were enriched in genes encoding secreted proteins. Population resequencing showed that chromosomal regions with high recombination rates were strongly correlated with regions of low linkage disequilibrium. Hence, genes in pathogen recombination hotspots are likely to evolve faster in natural populations and may represent a greater threat to the host. PMID:26392286

Chromosomal localization and structure of the human type II IMP dehydrogenase gene

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

Glesne, D.; Huberman, E.; Collart, F.

1994-05-01

We determined the chromosomal localization and structure of the gene encoding human type II inosine 5{prime}-monophosphate dehydrogenase (IMPDH, EC 1.1.1.205), an enzyme associated with cellular proliferation, malignant transformation, and differentiation. Using polymerase chain reaction (PCR) primers specific for type II IMPDH, we screened a panel of human-Chinese hamster cell somatic hybrids and a separate deletion panel of chromosome 3 hybrids and localized the gene to 3p21.1{yields}p24.2. Two overlapping yeast artificial chromosome clones containing the full gene for type II IMPDH were isolated and a physical map of 117 kb of human genomic DNA in this region of chromosome 3 wasmore » constructed. The gene for type II IMPDH was localized and oriented on this map and found to span no more than 12.5 kb.« less

The ubiquitous mitochondrial creatine kinase gene maps to a conserved region on human chromosome 15q15 and mouse chromosome 2 bands F1-F3

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

Steeghs, K.; Wieringa, B.; Merkx, G.

1994-11-01

Members of the creatine kinase isoenzyme family (CKs; EC 2.7.3.2) are found in mitochondria and specialized subregions of the cytoplasm and catalyze the reversible exchange of high-energy phosphoryl between ATP and phosphocreatine. At least four functionally active genes, which encode the distinct CK subunits CKB, CKM, CKMT1 (ubiquitous), and CKMT2 (sarcomeric), and a variable number of CKB pseudogenes have been identified. Here, we report the use of a CKMT1 containing phage to map the CKMT1 gene by in situ hybridization on both human and mouse chromosomes.

dAdd1 and dXNP prevent genome instability by maintaining HP1a localization at Drosophila telomeres.

PubMed

Chavez, Joselyn; Murillo-Maldonado, Juan Manuel; Bahena, Vanessa; Cruz, Ana Karina; Castañeda-Sortibrán, América; Rodriguez-Arnaiz, Rosario; Zurita, Mario; Valadez-Graham, Viviana

2017-12-01

Telomeres are important contributors to genome stability, as they prevent linear chromosome end degradation and contribute to the avoidance of telomeric fusions. An important component of the telomeres is the heterochromatin protein 1a (HP1a). Mutations in Su(var)205, the gene encoding HP1a in Drosophila, result in telomeric fusions, retrotransposon regulation loss and larger telomeres, leading to chromosome instability. Previously, it was found that several proteins physically interact with HP1a, including dXNP and dAdd1 (orthologues to the mammalian ATRX gene). In this study, we found that mutations in the genes encoding the dXNP and dAdd1 proteins affect chromosome stability, causing chromosomal aberrations, including telomeric defects, similar to those observed in Su(var)205 mutants. In somatic cells, we observed that dXNP and dAdd1 participate in the silencing of the telomeric HTT array of retrotransposons, preventing anomalous retrotransposon transcription and integration. Furthermore, the lack of dAdd1 results in the loss of HP1a from the telomeric regions without affecting other chromosomal HP1a binding sites; mutations in dxnp also affected HP1a localization but not at all telomeres, suggesting a specialized role for dAdd1 and dXNP proteins in locating HP1a at the tips of the chromosomes. These results place dAdd1 as an essential regulator of HP1a localization and function in the telomere heterochromatic domain.

Linkage of autosomal recessive lamellar ichthyosis to chromosome 14q

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

Russell, L.J.; Compton, J.G.; Bale, S.J.

The authors have mapped the locus for lamellar ichthyosis (LI), an autosomal recessive skin disease characterized by abnormal cornification of the epidermis. Analysis using both inbred and outbred families manifesting severe LI showed complete linkage to several markers within a 9.3-cM region on chromosome 14q11. Affected individuals in inbred families were also found to have striking homozygosity for markers in this region. Linkage-based genetic counseling and prenatal diagnosis is now available for informative at-risk families. Several transcribed genes have been mapped to the chromosome 14 region containing the LI gene. The transglutaminase 1 gene (TGM1), which encodes one of themore » enzymes responsible for cross-linking epidermal proteins during formation of the stratum corneum, maps to this interval. The TGM1 locus was completely linked to LI (Z = 9.11), suggesting that TGM1 is a good candidate for further investigation of this disorder. The genes for four serine proteases also map to this region but are expressed only in hematopoietic or mast cells, making them less likely candidates.« less

The genome of Brucella melitensis.

PubMed

DelVecchio, Vito G; Kapatral, Vinayak; Elzer, Philip; Patra, Guy; Mujer, Cesar V

2002-12-20

The genome of Brucella melitensis strain 16M was sequenced and contained 3,294,931 bp distributed over two circular chromosomes. Chromosome I was composed of 2,117,144 bp and chromosome II has 1,177,787 bp. A total of 3,198 ORFs were predicted. The origins of replication of the chromosomes are similar to each other and to those of other alpha-proteobacteria. Housekeeping genes such as those that encode for DNA replication, protein synthesis, core metabolism, and cell-wall biosynthesis were found on both chromosomes. Genes encoding adhesins, invasins, and hemolysins were also identified.

Evolutionary rate of a gene affected by chromosomal position.

PubMed

Perry, J; Ashworth, A

1999-09-09

Genes evolve at different rates depending on the strength of selective pressure to maintain their function. Chromosomal position can also have an influence [1] [2]. The pseudoautosomal region (PAR) of mammalian sex chromosomes is a small region of sequence identity that is the site of an obligatory pairing and recombination event between the X and Y chromosomes during male meiosis [3] [4] [5] [6]. During female meiosis, X chromosomes can pair and recombine along their entire length. Recombination in the PAR is therefore approximately 10 times greater in male meiosis compared with female meiosis [4] [5] [6]. The gene Fxy (also known as MID1 [7]) spans the pseudoautosomal boundary (PAB) in the laboratory mouse (Mus musculus domesticus, C57BL/6) such that the 5' three exons of the gene are located on the X chromosome but the seven exons encoding the carboxy-terminal two-thirds of the protein are located within the PAR and are therefore present on both the X and Y chromosomes [8]. In humans [7] [9], the rat, and the wild mouse species Mus spretus, the gene is entirely X-unique. Here, we report that the rate of sequence divergence of the 3' end of the Fxy gene is much higher (estimated at 170-fold higher for synonymous sites) when pseudoautosomal (present on both the X and Y chromosomes) than when X-unique. Thus, chromosomal position can directly affect the rate of evolution of a gene. This finding also provides support for the suggestion that regions of the genome with a high recombination frequency, such as the PAR, may have an intrinsically elevated rate of sequence divergence.

Physical structure and chromosomal localization of a gene encoding human p58[sup clk-1], a cell division control related protein kinase

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

Eipers, P.G.

1992-01-01

The gene for the human p58[sup clk[minus]1] protein kinase, a cell division control-related gene, has been mapped by somatic cell hybrid analyses, in situ localization with the chromosomal gene, and nested polymerase chain reaction amplification of microdissected chromosomes. These studies indicate that the expressed p58[sup clk[minus]1] chromosomal gene maps to 1p36, while a highly related p58[sup clk[minus]1] sequence of unknown nature maps to chromosome 15. Assignment of a p34[sup cdc2]-related gene to 1p36 region, including neuroblastoma, ductal carcinoma of the breast, malignant melanoma, Merkel cell carcinoma and endocrine neoplasia among others. Aberrant expression of this protein kinase negatively regulates normalmore » cellular growth. The p58[sup clk[minus]1] protein contains a central domain of 299 amino acids that is 46% identical to human p34[sup cdc2], the master mitotic protein kinase. This dissertation details the complete structure of the p58[sup clk[minus]1] chromosomal gene, including its putative promoter region, transcriptional start sites, exonic sequences, and intron/exon boundary sequences. The gene is 10 kb in size and contains 12 exons and 11 introns. Interestingly, the rather large 2.0 kb 3[prime] untranslated region is interrupted by an intron that separates a region containing numerous AUUUA destabilization motifs from the coding region. Furthermore, the expression of this gene in normal human tissues, as well as several human tumor cell samples and lines, is examined. The origin of multiple human transcripts from the same chromosomal gene, and the possible differential stability of these various transcripts, is discussed with regard to the transcriptional and post-transcriptional regulation of this gene. This is the first report of the chromosomal gene structure of a member of the p34[sup cdc2] supergene family.« less

Horizontal gene transfer in Histophilus somni and its role in the evolution of pathogenic strain 2336, as determined by comparative genomic analyses

PubMed Central

2011-01-01

Background Pneumonia and myocarditis are the most commonly reported diseases due to Histophilus somni, an opportunistic pathogen of the reproductive and respiratory tracts of cattle. Thus far only a few genes involved in metabolic and virulence functions have been identified and characterized in H. somni using traditional methods. Analyses of the genome sequences of several Pasteurellaceae species have provided insights into their biology and evolution. In view of the economic and ecological importance of H. somni, the genome sequence of pneumonia strain 2336 has been determined and compared to that of commensal strain 129Pt and other members of the Pasteurellaceae. Results The chromosome of strain 2336 (2,263,857 bp) contained 1,980 protein coding genes, whereas the chromosome of strain 129Pt (2,007,700 bp) contained only 1,792 protein coding genes. Although the chromosomes of the two strains differ in size, their average GC content, gene density (total number of genes predicted on the chromosome), and percentage of sequence (number of genes) that encodes proteins were similar. The chromosomes of these strains also contained a number of discrete prophage regions and genomic islands. One of the genomic islands in strain 2336 contained genes putatively involved in copper, zinc, and tetracycline resistance. Using the genome sequence data and comparative analyses with other members of the Pasteurellaceae, several H. somni genes that may encode proteins involved in virulence (e.g., filamentous haemaggutinins, adhesins, and polysaccharide biosynthesis/modification enzymes) were identified. The two strains contained a total of 17 ORFs that encode putative glycosyltransferases and some of these ORFs had characteristic simple sequence repeats within them. Most of the genes/loci common to both the strains were located in different regions of the two chromosomes and occurred in opposite orientations, indicating genome rearrangement since their divergence from a common ancestor. Conclusions Since the genome of strain 129Pt was ~256,000 bp smaller than that of strain 2336, these genomes provide yet another paradigm for studying evolutionary gene loss and/or gain in regard to virulence repertoire and pathogenic ability. Analyses of the complete genome sequences revealed that bacteriophage- and transposon-mediated horizontal gene transfer had occurred at several loci in the chromosomes of strains 2336 and 129Pt. It appears that these mobile genetic elements have played a major role in creating genomic diversity and phenotypic variability among the two H. somni strains. PMID:22111657

Horizontal gene transfer in Histophilus somni and its role in the evolution of pathogenic strain 2336, as determined by comparative genomic analyses.

PubMed

Siddaramappa, Shivakumara; Challacombe, Jean F; Duncan, Alison J; Gillaspy, Allison F; Carson, Matthew; Gipson, Jenny; Orvis, Joshua; Zaitshik, Jeremy; Barnes, Gentry; Bruce, David; Chertkov, Olga; Detter, J Chris; Han, Cliff S; Tapia, Roxanne; Thompson, Linda S; Dyer, David W; Inzana, Thomas J

2011-11-23

Pneumonia and myocarditis are the most commonly reported diseases due to Histophilus somni, an opportunistic pathogen of the reproductive and respiratory tracts of cattle. Thus far only a few genes involved in metabolic and virulence functions have been identified and characterized in H. somni using traditional methods. Analyses of the genome sequences of several Pasteurellaceae species have provided insights into their biology and evolution. In view of the economic and ecological importance of H. somni, the genome sequence of pneumonia strain 2336 has been determined and compared to that of commensal strain 129Pt and other members of the Pasteurellaceae. The chromosome of strain 2336 (2,263,857 bp) contained 1,980 protein coding genes, whereas the chromosome of strain 129Pt (2,007,700 bp) contained only 1,792 protein coding genes. Although the chromosomes of the two strains differ in size, their average GC content, gene density (total number of genes predicted on the chromosome), and percentage of sequence (number of genes) that encodes proteins were similar. The chromosomes of these strains also contained a number of discrete prophage regions and genomic islands. One of the genomic islands in strain 2336 contained genes putatively involved in copper, zinc, and tetracycline resistance. Using the genome sequence data and comparative analyses with other members of the Pasteurellaceae, several H. somni genes that may encode proteins involved in virulence (e.g., filamentous haemaggutinins, adhesins, and polysaccharide biosynthesis/modification enzymes) were identified. The two strains contained a total of 17 ORFs that encode putative glycosyltransferases and some of these ORFs had characteristic simple sequence repeats within them. Most of the genes/loci common to both the strains were located in different regions of the two chromosomes and occurred in opposite orientations, indicating genome rearrangement since their divergence from a common ancestor. Since the genome of strain 129Pt was ~256,000 bp smaller than that of strain 2336, these genomes provide yet another paradigm for studying evolutionary gene loss and/or gain in regard to virulence repertoire and pathogenic ability. Analyses of the complete genome sequences revealed that bacteriophage- and transposon-mediated horizontal gene transfer had occurred at several loci in the chromosomes of strains 2336 and 129Pt. It appears that these mobile genetic elements have played a major role in creating genomic diversity and phenotypic variability among the two H. somni strains.

Genetic mapping of a locus for multiple ephiphyseal dysplasia (EDM2) to a region of chromosome 1 containing a type IX collagen gene

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

Briggs, M.D.; Choi, HiChang; Warman, M.L.

1994-10-01

Multiple epiphyseal dysplasia (MED) is a dominantly inherited chondrodysplasia characterized by mild short stature and early-onset osteoarthrosis. Some forms of MED clinically resemble another chondrodysplasia phenotype, the mild form of pseudoachondroplasia (PSACH). On the basis of their clinical similarities as well as similar ultra-structural and biochemical features in cartilage from some patients, it has been proposed that MED and PSACH belong to a single bone-dysplasia family. Recently, both mild and severe PSACH as well as a form of MED have been linked to the same interval on chromosome 19, suggesting that they may be allelic disorders. Linkage studies with themore » chromosome 19 markers were carried out in a large family with MED and excluded the previously identified interval. Using this family, we have identified a MED locus on the short arm of chromosome 1, in a region containing the gene (COL9A2) that encodes the {alpha}2 chain of type IX collagen, a structural component of the cartilage extracellular matrix. 39 refs., 3 figs., 3 tabs.« less

The Impact of Recombination Hotspots on Genome Evolution of a Fungal Plant Pathogen.

PubMed

Croll, Daniel; Lendenmann, Mark H; Stewart, Ethan; McDonald, Bruce A

2015-11-01

Recombination has an impact on genome evolution by maintaining chromosomal integrity, affecting the efficacy of selection, and increasing genetic variability in populations. Recombination rates are a key determinant of the coevolutionary dynamics between hosts and their pathogens. Historic recombination events created devastating new pathogens, but the impact of ongoing recombination in sexual pathogens is poorly understood. Many fungal pathogens of plants undergo regular sexual cycles, and sex is considered to be a major factor contributing to virulence. We generated a recombination map at kilobase-scale resolution for the haploid plant pathogenic fungus Zymoseptoria tritici. To account for intraspecific variation in recombination rates, we constructed genetic maps from two independent crosses. We localized a total of 10,287 crossover events in 441 progeny and found that recombination rates were highly heterogeneous within and among chromosomes. Recombination rates on large chromosomes were inversely correlated with chromosome length. Short accessory chromosomes often lacked evidence for crossovers between parental chromosomes. Recombination was concentrated in narrow hotspots that were preferentially located close to telomeres. Hotspots were only partially conserved between the two crosses, suggesting that hotspots are short-lived and may vary according to genomic background. Genes located in hotspot regions were enriched in genes encoding secreted proteins. Population resequencing showed that chromosomal regions with high recombination rates were strongly correlated with regions of low linkage disequilibrium. Hence, genes in pathogen recombination hotspots are likely to evolve faster in natural populations and may represent a greater threat to the host. Copyright © 2015 by the Genetics Society of America.

Characterization of a TOL-like plasmid from Alcaligenes eutrophus that controls expression of a chromosomally encoded p-cresol pathway.

PubMed Central

Hughes, E J; Bayly, R C; Skurray, R A

1984-01-01

Alcaligenes eutrophus wild-type strain 345 metabolizes m- and p-toluate via a catechol meta-cleavage pathway. DNA analysis, curing studies, and transfer of this phenotype by conjugation and transformation showed that the degradative genes are encoded on a self-transmissible 85-kilobase plasmid, pRA1000. HindIII and XhoI restriction endonuclease analysis of pRA1000 showed it to be similar to the archetypal TOL plasmid, pWWO, differing in the case of HindIII only by the absence of fragments B and D present in pWWO. In strain 345, the presence of pRA1000 prevented the expression of chromosomally encoded enzymes required for the degradation of p-cresol, whereas these enzymes were expressed in strains cured of pRA1000. On the basis of studies with an R68.45-pRA1000 cointegrate plasmid, pRA1001, we conclude that the gene(s) responsible for the effect of p-cresol degradation resides within or near the m- and p-toluate degradative region on pRA1000. Images PMID:6325399

Cloning, expression analysis, and chromosomal localization of HIP1R, an isolog of huntingtin interacting protein (HIP1).

PubMed

Seki, N; Muramatsu, M; Sugano, S; Suzuki, Y; Nakagawara, A; Ohhira, M; Hayashi, A; Hori, T; Saito, T

1998-01-01

Huntington disease (HD) is an inherited neurodegenerative disorder which is associated with CAG expansion in the coding region of the gene for huntingtin protein. Recently, a huntingtin interacting protein, HIP1, was isolated by the yeast two-hybrid system. Here we report the isolation of a cDNA clone for HIP1R (huntingtin interacting protein-1 related), which encodes a predicted protein product sharing a striking homology with HIP1. RT-PCR analysis showed that the messenger RNA was ubiquitously expressed in various human tissues. Based on PCR-assisted analysis of a radiation hybrid panel and fluorescence in situ hybridization, HIP1R was localized to the q24 region of chromosome 12.

Complementary DNA characterization and chromosomal localization of a human gene related to the poliovirus receptor-encoding gene.

PubMed

Lopez, M; Eberlé, F; Mattei, M G; Gabert, J; Birg, F; Bardin, F; Maroc, C; Dubreuil, P

1995-04-03

The human poliovirus (PV) receptor (PVR) is a member of the immunoglobulin (Ig) superfamily with unknown cellular function. We have isolated a human PVR-related (PRR) cDNA. The deduced amino acid (aa) sequence of PRR showed, in the extracellular region, 51.7 and 54.3% similarity with human PVR and with the murine PVR homolog, respectively. The cDNA coding sequence is 1.6-kb long and encodes a deduced 57-kDa protein; this protein has a structural organization analogous to that of PVR, that is, one V- and two C-set Ig domains, with a conserved number of aa. Northern blot analysis indicated that a major 5.9-kb transcript is present in all normal human tissues tested. In situ hybridization showed that the PRR gene is located at bands q23-q24 of human chromosome 11.

Identification of Two Candidate Tumor Suppressor Genes on Chromosome 17p13.3: Assessment of Their Roles in Breast and Ovarian Carcinogenesis

DTIC Science & Technology

1997-07-01

minimum region of allelic loss on chromosome 17p 13.3, between polymorphic markers D17S5 and D17S28, in genomic DNA from breast and ovarian tumors (Figure 1...encode proteins of 443 and 227 amino acids, with no known functional motifs. Comparison of genomic and cDNA sequences showed that the genes overlap...is tissue specific (Figure 4). When zoo blots comprised of EcoRI fragments of genomic DNA from various species were probed with the unique exon 1 of

Delineation and analysis of chromosomal regions specifying Yersinia pestis.

PubMed

Derbise, Anne; Chenal-Francisque, Viviane; Huon, Christèle; Fayolle, Corinne; Demeure, Christian E; Chane-Woon-Ming, Béatrice; Médigue, Claudine; Hinnebusch, B Joseph; Carniel, Elisabeth

2010-09-01

Yersinia pestis, the causative agent of plague, has recently diverged from the less virulent enteropathogen Yersinia pseudotuberculosis. Its emergence has been characterized by massive genetic loss and inactivation and limited gene acquisition. The acquired genes include two plasmids, a filamentous phage, and a few chromosomal loci. The aim of this study was to characterize the chromosomal regions acquired by Y. pestis. Following in silico comparative analysis and PCR screening of 98 strains of Y. pseudotuberculosis and Y. pestis, we found that eight chromosomal loci (six regions [R1pe to R6pe] and two coding sequences [CDS1pe and CDS2pe]) specified Y. pestis. Signatures of integration by site specific or homologous recombination were identified for most of them. These acquisitions and the loss of ancestral DNA sequences were concentrated in a chromosomal region opposite to the origin of replication. The specific regions were acquired very early during Y. pestis evolution and were retained during its microevolution, suggesting that they might bring some selective advantages. Only one region (R3pe), predicted to carry a lambdoid prophage, is most likely no longer functional because of mutations. With the exception of R1pe and R2pe, which have the potential to encode a restriction/modification and a sugar transport system, respectively, no functions could be predicted for the other Y. pestis-specific loci. To determine the role of the eight chromosomal loci in the physiology and pathogenicity of the plague bacillus, each of them was individually deleted from the bacterial chromosome. None of the deletants exhibited defects during growth in vitro. Using the Xenopsylla cheopis flea model, all deletants retained the capacity to produce a stable and persistent infection and to block fleas. Similarly, none of the deletants caused any acute flea toxicity. In the mouse model of infection, all deletants were fully virulent upon subcutaneous or aerosol infections. Therefore, our results suggest that acquisition of new chromosomal materials has not been of major importance in the dramatic change of life cycle that has accompanied the emergence of Y. pestis.

Expression cloning and chromosomal mapping of the leukocyte activation antigen CD97, a new seven-span transmembrane molecule of the secretin receptor superfamily with an unusual extracellular domain

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

Hamann, J.; Hamann, D.; Lier, R.A.W.

1995-08-15

CD97 is a monomeric glycoprotein of 75 to 85 kDa that is induced rapidly on the surface of most leukocytes upon activation. We herein report the isolation of a cDNA encoding human CD97 by expression cloning in COS cells. The 3-kb cDNA clone encodes a mature polypeptide chain of 722 amino acids with a predicted molecular mass of 79 kDa. Within the C-terminal part of the protein, a region with seven hydrophobic segments was identified, suggesting that CD97 is a seven-span transmembrane molecule. Sequence comparison indicates that CD97 is the first leukocyte Ag in a recently described superfamily that includesmore » the receptors for secretin, calcitonin, and other mammalian and insect peptide hormones. Different from these receptors, CD97 has an extended extracellular region of 433 amino acids that possesses three N-terminal epidermal growth factor-like domains, two of them with a calcium-binding site, and single Arg-Gly-Asp (RGD) motif. The existence of structural elements characteristic for extracellular matrix proteins in a seven-span transmembrane molecule makes CD97 a receptor potentially involved in both adhesion and signaling processes early after leukocyte activation. The gene encoding CD97 is localized on chromosome 19 (19p13.12-13.2).« less

A Family of Zinc Finger Proteins Is Required forChromosome-specific Pairing and Synapsis during Meiosis in C.elegans

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

Phillips, Carolyn M.; Dernburg, Abby F.

2006-06-07

Homologous chromosome pairing and synapsis are prerequisitefor accurate chromosome segregation during meiosis. Here, we show that afamily of four related C2H2 zinc-finger proteins plays a central role inthese events in C. elegans. These proteins are encoded within a tandemgene cluster. In addition to the X-specific HIM-8 protein, threeadditional paralogs collectively mediate the behavior of the fiveautosomes. Each chromosome relies on a specific member of the family topair and synapse with its homolog. These "ZIM" proteins concentrate atspecial regions called meiotic pairing centers on the correspondingchromosomes. These sites are dispersed along the nuclear envelope duringearly meiotic prophase, suggesting a role analogousmore » to thetelomere-mediated meiotic bouquet in other organisms. To gain insightinto the evolution of these components, wecharacterized homologs in C.briggsae and C. remanei, which revealed changes in copy number of thisgene family within the nematode lineage.« less

Genome-Wide Association Study of White Blood Cell Count in 16,388 African Americans: the Continental Origins and Genetic Epidemiology Network (COGENT)

PubMed Central

Arepalli, Sampath; Britton, Angela; Chen, Zhao; Couper, David; Curb, J. David; Eaton, Charles B.; Fornage, Myriam; Grant, Struan F. A.; Harris, Tamara B.; Hernandez, Dena; Kamatini, Naoyuki; Keating, Brendan J.; Kubo, Michiaki; LaCroix, Andrea; Lange, Leslie A.; Liu, Simin; Lohman, Kurt; Meng, Yan; Mohler, Emile R.; Musani, Solomon; Nakamura, Yusuke; O'Donnell, Christopher J.; Okada, Yukinori; Palmer, Cameron D.; Papanicolaou, George J.; Patel, Kushang V.; Singleton, Andrew B.; Takahashi, Atsushi; Tang, Hua; Taylor, Herman A.; Taylor, Kent; Thomson, Cynthia; Yanek, Lisa R.; Yang, Lingyao; Ziv, Elad; Zonderman, Alan B.; Folsom, Aaron R.; Evans, Michele K.; Liu, Yongmei; Becker, Diane M.; Snively, Beverly M.; Wilson, James G.

2011-01-01

Total white blood cell (WBC) and neutrophil counts are lower among individuals of African descent due to the common African-derived “null” variant of the Duffy Antigen Receptor for Chemokines (DARC) gene. Additional common genetic polymorphisms were recently associated with total WBC and WBC sub-type levels in European and Japanese populations. No additional loci that account for WBC variability have been identified in African Americans. In order to address this, we performed a large genome-wide association study (GWAS) of total WBC and cell subtype counts in 16,388 African-American participants from 7 population-based cohorts available in the Continental Origins and Genetic Epidemiology Network. In addition to the DARC locus on chromosome 1q23, we identified two other regions (chromosomes 4q13 and 16q22) associated with WBC in African Americans (P<2.5×10−8). The lead SNP (rs9131) on chromosome 4q13 is located in the CXCL2 gene, which encodes a chemotactic cytokine for polymorphonuclear leukocytes. Independent evidence of the novel CXCL2 association with WBC was present in 3,551 Hispanic Americans, 14,767 Japanese, and 19,509 European Americans. The index SNP (rs12149261) on chromosome 16q22 associated with WBC count is located in a large inter-chromosomal segmental duplication encompassing part of the hydrocephalus inducing homolog (HYDIN) gene. We demonstrate that the chromosome 16q22 association finding is most likely due to a genotyping artifact as a consequence of sequence similarity between duplicated regions on chromosomes 16q22 and 1q21. Among the WBC loci recently identified in European or Japanese populations, replication was observed in our African-American meta-analysis for rs445 of CDK6 on chromosome 7q21 and rs4065321 of PSMD3-CSF3 region on chromosome 17q21. In summary, the CXCL2, CDK6, and PSMD3-CSF3 regions are associated with WBC count in African American and other populations. We also demonstrate that large inter-chromosomal duplications can result in false positive associations in GWAS. PMID:21738479

A common FGFR3 gene mutation is present in achondroplasia but not in hypochondroplasia.

PubMed

Stoilov, I; Kilpatrick, M W; Tsipouras, P

1995-01-02

Achondroplasia is the most common type of genetic dwarfism. It is characterized by disproportionate short stature and other skeletal anomalies resulting from a defect in the maturation of the chondrocytes in the growth plate of the cartilage. Recent studies mapped the achondroplasia gene on chromosome region 4p16.3 and identified a common mutation in the gene encoding the fibroblast growth factor receptor 3 (FGFR3). In an analysis of 19 achondroplasia families from a variety of ethnic backgrounds we confirmed the presence of the G380R mutation in 21 of 23 achondroplasia chromosomes studied. In contrast, the G380R mutation was not found in any of the 8 hypochondroplasia chromosomes studied. Furthermore, linkage studies in a 3-generation family with hypochondroplasia show discordant segregation with markers in the 4p16.3 region suggesting that at least some cases of hypochondroplasia are caused by mutations in a gene other than FGFR3.

Insights into the evolution of mammalian telomerase: Platypus TERT shares similarities with genes of birds and other reptiles and localizes on sex chromosomes

PubMed Central

2012-01-01

Background The TERT gene encodes the catalytic subunit of the telomerase complex and is responsible for maintaining telomere length. Vertebrate telomerase has been studied in eutherian mammals, fish, and the chicken, but less attention has been paid to other vertebrates. The platypus occupies an important evolutionary position, providing unique insight into the evolution of mammalian genes. We report the cloning of a platypus TERT (OanTERT) ortholog, and provide a comparison with genes of other vertebrates. Results The OanTERT encodes a protein with a high sequence similarity to marsupial TERT and avian TERT. Like the TERT of sauropsids and marsupials, as well as that of sharks and echinoderms, OanTERT contains extended variable linkers in the N-terminal region suggesting that they were present already in basal vertebrates and lost independently in ray-finned fish and eutherian mammals. Several alternatively spliced OanTERT variants structurally similar to avian TERT variants were identified. Telomerase activity is expressed in all platypus tissues like that of cold-blooded animals and murine rodents. OanTERT was localized on pseudoautosomal regions of sex chromosomes X3/Y2, expanding the homology between human chromosome 5 and platypus sex chromosomes. Synteny analysis suggests that TERT co-localized with sex-linked genes in the last common mammalian ancestor. Interestingly, female platypuses express higher levels of telomerase in heart and liver tissues than do males. Conclusions OanTERT shares many features with TERT of the reptilian outgroup, suggesting that OanTERT represents the ancestral mammalian TERT. Features specific to TERT of eutherian mammals have, therefore, evolved more recently after the divergence of monotremes. PMID:22655747

Insights into the evolution of mammalian telomerase: platypus TERT shares similarities with genes of birds and other reptiles and localizes on sex chromosomes.

PubMed

Hrdličková, Radmila; Nehyba, Jiří; Lim, Shu Ly; Grützner, Frank; Bose, Henry R

2012-06-01

The TERT gene encodes the catalytic subunit of the telomerase complex and is responsible for maintaining telomere length. Vertebrate telomerase has been studied in eutherian mammals, fish, and the chicken, but less attention has been paid to other vertebrates. The platypus occupies an important evolutionary position, providing unique insight into the evolution of mammalian genes. We report the cloning of a platypus TERT (OanTERT) ortholog, and provide a comparison with genes of other vertebrates. The OanTERT encodes a protein with a high sequence similarity to marsupial TERT and avian TERT. Like the TERT of sauropsids and marsupials, as well as that of sharks and echinoderms, OanTERT contains extended variable linkers in the N-terminal region suggesting that they were present already in basal vertebrates and lost independently in ray-finned fish and eutherian mammals. Several alternatively spliced OanTERT variants structurally similar to avian TERT variants were identified. Telomerase activity is expressed in all platypus tissues like that of cold-blooded animals and murine rodents. OanTERT was localized on pseudoautosomal regions of sex chromosomes X3/Y2, expanding the homology between human chromosome 5 and platypus sex chromosomes. Synteny analysis suggests that TERT co-localized with sex-linked genes in the last common mammalian ancestor. Interestingly, female platypuses express higher levels of telomerase in heart and liver tissues than do males. OanTERT shares many features with TERT of the reptilian outgroup, suggesting that OanTERT represents the ancestral mammalian TERT. Features specific to TERT of eutherian mammals have, therefore, evolved more recently after the divergence of monotremes.

Physical Mapping of Amplified Copies of the 5-Enolpyruvylshikimate-3-Phosphate Synthase Gene in Glyphosate-Resistant Amaranthus tuberculatus1[OPEN

PubMed Central

Dillon, Andrew; Varanasi, Vijay K.; Koo, Dal-Hoe; Nakka, Sridevi; Peterson, Dallas E.; Friebe, Bernd

2017-01-01

Recent and rapid evolution of resistance to glyphosate, the most widely used herbicides, in several weed species, including common waterhemp (Amaranthus tuberculatus), poses a serious threat to sustained crop production. We report that glyphosate resistance in A. tuberculatus was due to amplification of the 5-enolpyruvylshikimate-3-P synthase (EPSPS) gene, which encodes the molecular target of glyphosate. There was a positive correlation between EPSPS gene copies and its transcript expression. We analyzed the distribution of EPSPS copies in the genome of A. tuberculatus using fluorescence in situ hybridization on mitotic metaphase chromosomes and interphase nuclei. Fluorescence in situ hybridization analysis mapped the EPSPS gene to pericentromeric regions of two homologous chromosomes in glyphosate sensitive A. tuberculatus. In glyphosate-resistant plants, a cluster of EPSPS genes on the pericentromeric region on one pair of homologous chromosomes was detected. Intriguingly, two highly glyphosate-resistant plants harbored an additional chromosome with several EPSPS copies besides the native chromosome pair with EPSPS copies. These results suggest that the initial event of EPSPS gene duplication may have occurred because of unequal recombination mediated by repetitive DNA. Subsequently, gene amplification may have resulted via several other mechanisms, such as chromosomal rearrangements, deletion/insertion, transposon-mediated dispersion, or possibly by interspecific hybridization. This report illustrates the physical mapping of amplified EPSPS copies in A. tuberculatus. PMID:27956489

Mapping of the gene encoding the melanocortin-1 ([alpha]-melanocyte stimulating hormone) receptor (MC1R) to human chromosome 16q24. 3 by fluorescence in situ hybridization

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

Gantz, I.; Yamada, Tadataka; Tashiro, Takao

1994-01-15

[alpha]-Melanocyte stimulating hormone ([alpha]-MSH), a hormone originally named for its ability to regulate pigmentation of melanocytes, is a 13-amino-acid post-translational product of the pro-opiomelanocortin (POMC) gene. [alpha]-MSH and the other products of POMC processing, which share the core heptapeptide amino acid sequence Met-Glu (Gly)-His-Phe-Arg-Trp-Gly (Asp), the adrenocorticotropic hormone (ACTH), [beta]-MSH, and [gamma]-MSH, are collectively referred to as melanocortins. While best known for their effects on the melanocyte (pigmentation) and adrenal cortical cells (steroidogenesis), melanocortins have been postulated to function in diverse activities, including enhancement of learning and memory, control of the cardiovascular system, analgesia, thermoregulation, immunomodulation, parturition, and neurotrophism. Tomore » identify the chromosomal band encoding the human melanocortin-1 receptor gene, 1 [mu]g of an EMBL clone coding region of the human MC1R and approximately 15 kb of surrounding DNA was labeled with biotin and hybridized to human metaphase chromosomes as previously described. The results indicate that the human MC1R gene is localized to 16q24.3. 15 refs., 1 fig.« less

Organization, chromosomal localization and promoter analysis of the gene encoding human acidic fibroblast growth factor intracellular binding protein.

PubMed Central

Kolpakova, E; Frengen, E; Stokke, T; Olsnes, S

2000-01-01

Acidic fibroblast growth factor (aFGF) intracellular binding protein (FIBP) is a protein found mainly in the nucleus that might be involved in the intracellular function of aFGF. Here we present a comparative analysis of the deduced amino acid sequences of human, murine and Drosophila FIBP analogues and demonstrate that FIBP is an evolutionarily conserved protein. The human gene spans more than 5 kb, comprising ten exons and nine introns, and maps to chromosome 11q13.1. Two slightly different splice variants found in different tissues were isolated and characterized. Sequence analysis of the region surrounding the translation start revealed a CpG island, a classical feature of widely expressed genes. Functional studies of the promoter region with a luciferase reporter system suggested a strong transcriptional activity residing within 600 bp of the 5' flanking region. PMID:11104667

Isolation and sequence analysis of the wheat B genome subtelomeric DNA.

PubMed

Salina, Elena A; Sergeeva, Ekaterina M; Adonina, Irina G; Shcherban, Andrey B; Afonnikov, Dmitry A; Belcram, Harry; Huneau, Cecile; Chalhoub, Boulos

2009-09-05

Telomeric and subtelomeric regions are essential for genome stability and regular chromosome replication. In this work, we have characterized the wheat BAC (bacterial artificial chromosome) clones containing Spelt1 and Spelt52 sequences, which belong to the subtelomeric repeats of the B/G genomes of wheats and Aegilops species from the section Sitopsis. The BAC library from Triticum aestivum cv. Renan was screened using Spelt1 and Spelt52 as probes. Nine positive clones were isolated; of them, clone 2050O8 was localized mainly to the distal parts of wheat chromosomes by in situ hybridization. The distribution of the other clones indicated the presence of different types of repetitive sequences in BACs. Use of different approaches allowed us to prove that seven of the nine isolated clones belonged to the subtelomeric chromosomal regions. Clone 2050O8 was sequenced and its sequence of 119,737 bp was annotated. It is composed of 33% transposable elements (TEs), 8.2% Spelt52 (namely, the subfamily Spelt52.2) and five non-TE-related genes. DNA transposons are predominant, making up 24.6% of the entire BAC clone, whereas retroelements account for 8.4% of the clone length. The full-length CACTA transposon Caspar covers 11,666 bp, encoding a transposase and CTG-2 proteins, and this transposon accounts for 40% of the DNA transposons. The in situ hybridization data for 2050O8 derived subclones in combination with the BLAST search against wheat mapped ESTs (expressed sequence tags) suggest that clone 2050O8 is located in the terminal bin 4BL-10 (0.95-1.0). Additionally, four of the predicted 2050O8 genes showed significant homology to four putative orthologous rice genes in the distal part of rice chromosome 3S and confirm the synteny to wheat 4BL. Satellite DNA sequences from the subtelomeric regions of diploid wheat progenitor can be used for selecting the BAC clones from the corresponding regions of hexaploid wheat chromosomes. It has been demonstrated for the first time that Spelt52 sequences were involved in the evolution of terminal regions of common wheat chromosomes. Our research provides new insights into the microcollinearity in the terminal regions of wheat chromosomes 4BL and rice chromosome 3S.

A History of the Discovery of Random X Chromosome Inactivation in the Human Female and its Significance

PubMed Central

Balderman, Sophia; Lichtman, Marshall A.

2011-01-01

Genetic determinants of sex in placental mammals developed by the evolution of primordial autosomes into the male and female sex chromosomes. The Y chromosome determines maleness by the action of the gene SRY, which encodes a protein that initiates a sequence of events prompting the embryonic gonads to develop into testes. The X chromosome in the absence of a Y chromosome results in a female by permitting the conversion of the embryonic gonads into ovaries. We trace the historical progress that resulted in the discovery that one X chromosome in the female is randomly inactivated in early embryogenesis, accomplishing approximate equivalency of X chromosome gene dosage in both sexes. This event results in half of the somatic cells in a tissue containing proteins encoded by the genes of the maternal X chromosome and half having proteins encoded by the genes of the paternal X chromosome, on average, accounting for the phenotype of a female heterozygote with an X chromosome mutation. The hypothesis of X chromosome inactivation as a random event early in embryogenesis was first described as a result of studies of variegated coat color in female mice. Similar results were found in women using the X chromosome-linked gene, glucose-6-phosphate dehydrogenase, studied in red cells. The random inactivation of the X chromosome-bearing genes for isoenzyme types A and B of glucose-6-phosphate dehydrogenase was used to establish the clonal origin of neoplasms in informative women with leiomyomas. Behind these discoveries are the stories of the men and women scientists whose research enlightened these aspects of X chromosome function and their implication for medicine. PMID:23908816

Comparative analysis of metazoan chromatin organization.

PubMed

Ho, Joshua W K; Jung, Youngsook L; Liu, Tao; Alver, Burak H; Lee, Soohyun; Ikegami, Kohta; Sohn, Kyung-Ah; Minoda, Aki; Tolstorukov, Michael Y; Appert, Alex; Parker, Stephen C J; Gu, Tingting; Kundaje, Anshul; Riddle, Nicole C; Bishop, Eric; Egelhofer, Thea A; Hu, Sheng'en Shawn; Alekseyenko, Artyom A; Rechtsteiner, Andreas; Asker, Dalal; Belsky, Jason A; Bowman, Sarah K; Chen, Q Brent; Chen, Ron A-J; Day, Daniel S; Dong, Yan; Dose, Andrea C; Duan, Xikun; Epstein, Charles B; Ercan, Sevinc; Feingold, Elise A; Ferrari, Francesco; Garrigues, Jacob M; Gehlenborg, Nils; Good, Peter J; Haseley, Psalm; He, Daniel; Herrmann, Moritz; Hoffman, Michael M; Jeffers, Tess E; Kharchenko, Peter V; Kolasinska-Zwierz, Paulina; Kotwaliwale, Chitra V; Kumar, Nischay; Langley, Sasha A; Larschan, Erica N; Latorre, Isabel; Libbrecht, Maxwell W; Lin, Xueqiu; Park, Richard; Pazin, Michael J; Pham, Hoang N; Plachetka, Annette; Qin, Bo; Schwartz, Yuri B; Shoresh, Noam; Stempor, Przemyslaw; Vielle, Anne; Wang, Chengyang; Whittle, Christina M; Xue, Huiling; Kingston, Robert E; Kim, Ju Han; Bernstein, Bradley E; Dernburg, Abby F; Pirrotta, Vincenzo; Kuroda, Mitzi I; Noble, William S; Tullius, Thomas D; Kellis, Manolis; MacAlpine, David M; Strome, Susan; Elgin, Sarah C R; Liu, Xiaole Shirley; Lieb, Jason D; Ahringer, Julie; Karpen, Gary H; Park, Peter J

2014-08-28

Genome function is dynamically regulated in part by chromatin, which consists of the histones, non-histone proteins and RNA molecules that package DNA. Studies in Caenorhabditis elegans and Drosophila melanogaster have contributed substantially to our understanding of molecular mechanisms of genome function in humans, and have revealed conservation of chromatin components and mechanisms. Nevertheless, the three organisms have markedly different genome sizes, chromosome architecture and gene organization. On human and fly chromosomes, for example, pericentric heterochromatin flanks single centromeres, whereas worm chromosomes have dispersed heterochromatin-like regions enriched in the distal chromosomal 'arms', and centromeres distributed along their lengths. To systematically investigate chromatin organization and associated gene regulation across species, we generated and analysed a large collection of genome-wide chromatin data sets from cell lines and developmental stages in worm, fly and human. Here we present over 800 new data sets from our ENCODE and modENCODE consortia, bringing the total to over 1,400. Comparison of combinatorial patterns of histone modifications, nuclear lamina-associated domains, organization of large-scale topological domains, chromatin environment at promoters and enhancers, nucleosome positioning, and DNA replication patterns reveals many conserved features of chromatin organization among the three organisms. We also find notable differences in the composition and locations of repressive chromatin. These data sets and analyses provide a rich resource for comparative and species-specific investigations of chromatin composition, organization and function.

Genomic structure and chromosomal localization of GML (GPI-anchored molecule-like protein), a gene induced by p53

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

Kimura, Yasutoshi; Furuhata, Tomohisa; Nakamura, Yusuke

1997-05-01

Among its known functions, tumor suppressor gene p53 serves as a transcriptional regulator and mediates various signals through activation of downstream genes. We recently identified a novel gene, GML (glycosylphosphatidylinositol (GPI)-anchored molecule-like protein), whose expression is specifically induced by wildtype p53. To characterize the GML gene further, we determined 35.8 kb of DNA sequence that included a consensus binding sequence for p53 and the entire GML gene. The GML gene consists of four exons, and the p53-binding sequence is present in the 5{prime}-flanking region. In genomic organization this gene resembles genes encoding murine Ly-6 glycoproteins, a human homologue of themore » Ly-6 family called RIG-E, and CD59; products of these genes, known as GPI-anchored proteins, are variously involved in signal transduction, cell-cell adhesion, and cell-matrix attachment. FISH analysis revealed that the GML gene is located on human chromosome 8q24.3. Genes encoding at least two other GPI-anchored molecules, E48 and RIG-E, are also located in this region. 20 refs., 2 figs., 1 tab.« less

Structural analysis of chromosomal rearrangements associated with the developmental mutations Ph, W19H, and Rw on mouse chromosome 5.

PubMed Central

Nagle, D L; Martin-DeLeon, P; Hough, R B; Bućan, M

1994-01-01

We are studying the chromosomal structure of three developmental mutations, dominant spotting (W), patch (Ph), and rump white (Rw) on mouse chromosome 5. These mutations are clustered in a region containing three genes encoding tyrosine kinase receptors (Kit, Pdgfra, and Flk1). Using probes for these genes and for a closely linked locus, D5Mn125, we established a high-resolution physical map covering approximately 2.8 Mb. The entire chromosomal segment mapped in this study is deleted in the W19H mutation. The map indicates the position of the Ph deletion, which encompasses not more than 400 kb around and including the Pdgfra gene. The map also places the distal breakpoint of the Rw inversion to a limited chromosomal segment between Kit and Pdgfra. In light of the structure of the Ph-W-Rw region, we interpret the previously published complementation analyses as indicating that the pigmentation defect in Rw/+ heterozygotes could be due to the disruption of Kit and/or Pdgfra regulatory sequences, whereas the gene(s) responsible for the recessive lethality of Rw/Rw embryos is not closely linked to the Ph and W loci and maps proximally to the W19H deletion. The structural analysis of chromosomal rearrangements associated with W19H, Ph, and Rw combined with the high-resolution physical mapping points the way toward the definition of these mutations in molecular terms and isolation of homologous genes on human chromosome 4. Images PMID:8041773

Chromosomal Organization and Sequence Diversity of Genes Encoding Lachrymatory Factor Synthase in Allium cepa L.

PubMed Central

Masamura, Noriya; McCallum, John; Khrustaleva, Ludmila; Kenel, Fernand; Pither-Joyce, Meegham; Shono, Jinji; Suzuki, Go; Mukai, Yasuhiko; Yamauchi,, Naoki; Shigyo, Masayoshi

2012-01-01

Lachrymatory factor synthase (LFS) catalyzes the formation of lachrymatory factor, one of the most distinctive traits of bulb onion (Allium cepa L.). Therefore, we used LFS as a model for a functional gene in a huge genome, and we examined the chromosomal organization of LFS in A. cepa by multiple approaches. The first-level analysis completed the chromosomal assignment of LFS gene to chromosome 5 of A. cepa via the use of a complete set of A. fistulosum–shallot (A. cepa L. Aggregatum group) monosomic addition lines. Subsequent use of an F2 mapping population from the interspecific cross A. cepa × A. roylei confirmed the assignment of an LFS locus to this chromosome. Sequence comparison of two BAC clones bearing LFS genes, LFS amplicons from diverse germplasm, and expressed sequences from a doubled haploid line revealed variation consistent with duplicated LFS genes. Furthermore, the BAC-FISH study using the two BAC clones as a probe showed that LFS genes are localized in the proximal region of the long arm of the chromosome. These results suggested that LFS in A. cepa is transcribed from at least two loci and that they are localized on chromosome 5. PMID:22690373

Identification of a basic helix-loop-helix-type transcription regulator gene in Aspergillus oryzae by systematically deleting large chromosomal segments.

PubMed

Jin, Feng Jie; Takahashi, Tadashi; Machida, Masayuki; Koyama, Yasuji

2009-09-01

We previously developed two methods (loop-out and replacement-type recombination) for generating large-scale chromosomal deletions that can be applied to more effective chromosomal engineering in Aspergillus oryzae. In this study, the replacement-type method is used to systematically delete large chromosomal DNA segments to identify essential and nonessential regions in chromosome 7 (2.93 Mb), which is the smallest A. oryzae chromosome and contains a large number of nonsyntenic blocks. We constructed 12 mutants harboring deletions that spanned 16- to 150-kb segments of chromosome 7 and scored phenotypic changes in the resulting mutants. Among the deletion mutants, strains designated Delta5 and Delta7 displayed clear phenotypic changes involving growth and conidiation. In particular, the Delta5 mutant exhibited vigorous growth and conidiation, potentially beneficial characteristics for certain industrial applications. Further deletion analysis allowed identification of the AO090011000215 gene as the gene responsible for the Delta5 mutant phenotype. The AO090011000215 gene was predicted to encode a helix-loop-helix binding protein belonging to the bHLH family of transcription factors. These results illustrate the potential of the approach for identifying novel functional genes.

Insensitivity of chromosome I and the cell cycle to blockage of replication and segregation of Vibrio cholerae chromosome II.

PubMed

Kadoya, Ryosuke; Chattoraj, Dhruba K

2012-01-01

Vibrio cholerae has two chromosomes (chrI and chrII) whose replication and segregation are under different genetic controls. The region covering the replication origin of chrI resembles that of the Escherichia coli chromosome, and both origins are under control of the highly conserved initiator, DnaA. The origin region of chrII resembles that of plasmids that have iterated initiator-binding sites (iterons) and is under control of the chrII-specific initiator, RctB. Both chrI and chrII encode chromosome-specific orthologs of plasmid partitioning proteins, ParA and ParB. Here, we have interfered with chrII replication, segregation, or both, using extra copies of sites that titrate RctB or ParB. Under these conditions, replication and segregation of chrI remain unaffected for at least 1 cell cycle. In this respect, chrI behaves similarly to the E. coli chromosome when plasmid maintenance is disturbed in the same cell. Apparently, no checkpoint exists to block cell division before the crippled chromosome is lost by a failure to replicate or to segregate. Whether blocking chrI replication can affect chrII replication remains to be tested. Chromosome replication, chromosome segregation, and cell division are the three main events of the cell cycle. They occur in an orderly fashion once per cell cycle. How the sequence of events is controlled is only beginning to be answered in bacteria. The finding of bacteria that possess more than one chromosome raises the important question: how are different chromosomes coordinated in their replication and segregation? It appears that in the evolution of the two-chromosome genome of V. cholerae, either the secondary chromosome adapted to the main chromosome to ensure its maintenance or it is maintained independently, as are bacterial plasmids. An understanding of chromosome coordination is expected to bear on the evolutionary process of chromosome acquisition and on the efficacy of possible strategies for selective elimination of a pathogen by targeting a specific chromosome.

Usher Syndrome Type III: Revised Genomic Structure of the USH3 Gene and Identification of Novel Mutations

PubMed Central

Fields, Randall R.; Zhou, Guimei; Huang, Dali; Davis, Jack R.; Möller, Claes; Jacobson, Samuel G.; Kimberling, William J.; Sumegi, Janos

2002-01-01

Usher syndrome type III is an autosomal recessive disorder characterized by progressive sensorineural hearing loss, vestibular dysfunction, and retinitis pigmentosa. The disease gene was localized to 3q25 and recently was identified by positional cloning. In the present study, we have revised the structure of the USH3 gene, including a new translation start site, 5′ untranslated region, and a transcript encoding a 232–amino acid protein. The mature form of the protein is predicted to contain three transmembrane domains and 204 residues. We have found four new disease-causing mutations, including one that appears to be relatively common in the Ashkenazi Jewish population. We have also identified mouse (chromosome 3) and rat (chromosome 2) orthologues, as well as two human paralogues on chromosomes 4 and 10. PMID:12145752

InterB multigenic family, a gene repertoire associated with subterminal chromosome regions of Encephalitozoon cuniculi and conserved in several human-infecting microsporidian species.

PubMed

Dia, Ndongo; Lavie, Laurence; Méténier, Guy; Toguebaye, Bhen S; Vivarès, Christian P; Cornillot, Emmanuel

2007-03-01

Microsporidia are fungi-related obligate intracellular parasites that infect numerous animals, including man. Encephalitozoon cuniculi harbours a very small genome (2.9 Mbp) with about 2,000 coding sequences (CDSs). Most repeated CDSs are of unknown function and are distributed in subterminal regions that mark the transitions between subtelomeric rDNA units and chromosome cores. A potential multigenic family (interB) encoding proteins within a size range of 579-641 aa was investigated by PCR and RT-PCR. Thirty members were finally assigned to the E. cuniculi interB family and a predominant interB transcript was found to originate from a newly identified gene on chromosome III. Microsporidian species from eight different genera infecting insects, fishes or mammals, were tested for a possible intra-phylum conservation of interB genes. Only representatives of the Encephalitozoon, Vittaforma and Brachiola genera, differing in host range but all able to invade humans, were positive. Molecular karyotyping of Brachiola algerae showed a complex set of chromosome bands, providing a haploid genome size estimate of 15-20 Mbp. In spite of this large difference in genome complexity, B. algerae and E. cuniculi shared some similar interB gene copies and a common location of interB genes in near-rDNA subterminal regions.

Identification of human chromosome 22 transcribed sequences with ORF expressed sequence tags

PubMed Central

de Souza, Sandro J.; Camargo, Anamaria A.; Briones, Marcelo R. S.; Costa, Fernando F.; Nagai, Maria Aparecida; Verjovski-Almeida, Sergio; Zago, Marco A.; Andrade, Luis Eduardo C.; Carrer, Helaine; El-Dorry, Hamza F. A.; Espreafico, Enilza M.; Habr-Gama, Angelita; Giannella-Neto, Daniel; Goldman, Gustavo H.; Gruber, Arthur; Hackel, Christine; Kimura, Edna T.; Maciel, Rui M. B.; Marie, Suely K. N.; Martins, Elizabeth A. L.; Nóbrega, Marina P.; Paçó-Larson, Maria Luisa; Pardini, Maria Inês M. C.; Pereira, Gonçalo G.; Pesquero, João Bosco; Rodrigues, Vanderlei; Rogatto, Silvia R.; da Silva, Ismael D. C. G.; Sogayar, Mari C.; de Fátima Sonati, Maria; Tajara, Eloiza H.; Valentini, Sandro R.; Acencio, Marcio; Alberto, Fernando L.; Amaral, Maria Elisabete J.; Aneas, Ivy; Bengtson, Mário Henrique; Carraro, Dirce M.; Carvalho, Alex F.; Carvalho, Lúcia Helena; Cerutti, Janete M.; Corrêa, Maria Lucia C.; Costa, Maria Cristina R.; Curcio, Cyntia; Gushiken, Tsieko; Ho, Paulo L.; Kimura, Elza; Leite, Luciana C. C.; Maia, Gustavo; Majumder, Paromita; Marins, Mozart; Matsukuma, Adriana; Melo, Analy S. A.; Mestriner, Carlos Alberto; Miracca, Elisabete C.; Miranda, Daniela C.; Nascimento, Ana Lucia T. O.; Nóbrega, Francisco G.; Ojopi, Élida P. B.; Pandolfi, José Rodrigo C.; Pessoa, Luciana Gilbert; Rahal, Paula; Rainho, Claudia A.; da Ro's, Nancy; de Sá, Renata G.; Sales, Magaly M.; da Silva, Neusa P.; Silva, Tereza C.; da Silva, Wilson; Simão, Daniel F.; Sousa, Josane F.; Stecconi, Daniella; Tsukumo, Fernando; Valente, Valéria; Zalcberg, Heloisa; Brentani, Ricardo R.; Reis, Luis F. L.; Dias-Neto, Emmanuel; Simpson, Andrew J. G.

2000-01-01

Transcribed sequences in the human genome can be identified with confidence only by alignment with sequences derived from cDNAs synthesized from naturally occurring mRNAs. We constructed a set of 250,000 cDNAs that represent partial expressed gene sequences and that are biased toward the central coding regions of the resulting transcripts. They are termed ORF expressed sequence tags (ORESTES). The 250,000 ORESTES were assembled into 81,429 contigs. Of these, 1,181 (1.45%) were found to match sequences in chromosome 22 with at least one ORESTES contig for 162 (65.6%) of the 247 known genes, for 67 (44.6%) of the 150 related genes, and for 45 of the 148 (30.4%) EST-predicted genes on this chromosome. Using a set of stringent criteria to validate our sequences, we identified a further 219 previously unannotated transcribed sequences on chromosome 22. Of these, 171 were in fact also defined by EST or full length cDNA sequences available in GenBank but not utilized in the initial annotation of the first human chromosome sequence. Thus despite representing less than 15% of all expressed human sequences in the public databases at the time of the present analysis, ORESTES sequences defined 48 transcribed sequences on chromosome 22 not defined by other sequences. All of the transcribed sequences defined by ORESTES coincided with DNA regions predicted as encoding exons by genscan. (http://genes.mit.edu/GENSCAN.html). PMID:11070084

The trans-activator RNF12 and cis-acting elements effectuate X chromosome inactivation independent of X-pairing.

PubMed

Barakat, Tahsin Stefan; Loos, Friedemann; van Staveren, Selma; Myronova, Elvira; Ghazvini, Mehrnaz; Grootegoed, J Anton; Gribnau, Joost

2014-03-20

X chromosome inactivation (XCI) in female placental mammals is a vital mechanism for dosage compensation between X-linked and autosomal genes. XCI starts with activation of Xist and silencing of the negative regulator Tsix, followed by cis spreading of Xist RNA over the future inactive X chromosome (Xi). Here, we show that XCI does not require physical contact between the two X chromosomes (X-pairing) but is regulated by trans-acting diffusible factors. We found that the X-encoded trans-acting and dose-dependent XCI-activator RNF12 acts in concert with the cis-regulatory region containing Jpx, Ftx, and Xpr to activate Xist and to overcome repression by Tsix. RNF12 acts at two subsequent steps; two active copies of Rnf12 drive initiation of XCI, and one copy needs to remain active to maintain XCI toward establishment of the Xi. This two-step mechanism ensures that XCI is very robust and fine-tuned, preventing XCI of both X chromosomes. Copyright © 2014 Elsevier Inc. All rights reserved.

The Genome Sequence of the Tomato-Pathogenic Actinomycete Clavibacter michiganensis subsp. michiganensis NCPPB382 Reveals a Large Island Involved in Pathogenicity▿ †

PubMed Central

Gartemann, Karl-Heinz; Abt, Birte; Bekel, Thomas; Burger, Annette; Engemann, Jutta; Flügel, Monika; Gaigalat, Lars; Goesmann, Alexander; Gräfen, Ines; Kalinowski, Jörn; Kaup, Olaf; Kirchner, Oliver; Krause, Lutz; Linke, Burkhard; McHardy, Alice; Meyer, Folker; Pohle, Sandra; Rückert, Christian; Schneiker, Susanne; Zellermann, Eva-Maria; Pühler, Alfred; Eichenlaub, Rudolf; Kaiser, Olaf; Bartels, Daniela

2008-01-01

Clavibacter michiganensis subsp. michiganensis is a plant-pathogenic actinomycete that causes bacterial wilt and canker of tomato. The nucleotide sequence of the genome of strain NCPPB382 was determined. The chromosome is circular, consists of 3.298 Mb, and has a high G+C content (72.6%). Annotation revealed 3,080 putative protein-encoding sequences; only 26 pseudogenes were detected. Two rrn operons, 45 tRNAs, and three small stable RNA genes were found. The two circular plasmids, pCM1 (27.4 kbp) and pCM2 (70.0 kbp), which carry pathogenicity genes and thus are essential for virulence, have lower G+C contents (66.5 and 67.6%, respectively). In contrast to the genome of the closely related organism Clavibacter michiganensis subsp. sepedonicus, the genome of C. michiganensis subsp. michiganensis lacks complete insertion elements and transposons. The 129-kb chp/tomA region with a low G+C content near the chromosomal origin of replication was shown to be necessary for pathogenicity. This region contains numerous genes encoding proteins involved in uptake and metabolism of sugars and several serine proteases. There is evidence that single genes located in this region, especially genes encoding serine proteases, are required for efficient colonization of the host. Although C. michiganensis subsp. michiganensis grows mainly in the xylem of tomato plants, no evidence for pronounced genome reduction was found. C. michiganensis subsp. michiganensis seems to have as many transporters and regulators as typical soil-inhabiting bacteria. However, the apparent lack of a sulfate reduction pathway, which makes C. michiganensis subsp. michiganensis dependent on reduced sulfur compounds for growth, is probably the reason for the poor survival of C. michiganensis subsp. michiganensis in soil. PMID:18192381

cDNA cloning, tissue distribution, and chromosomal localization of myelodysplasia/myeloid leukemia factor 2 (MLF2).

PubMed

Kuefer, M U; Look, A T; Williams, D C; Valentine, V; Naeve, C W; Behm, F G; Mullersman, J E; Yoneda-Kato, N; Montgomery, K; Kucherlapati, R; Morris, S W

1996-07-15

A fusion gene between nucleophosmin (NPM) and myelodysplasia/myeloid leukemia factor 1 (MLF1) is formed by a recurrent t(3;5)(q25.1;q34) in myelodysplastic syndrome and acute myeloid leukemia. Here we report the identification of a novel gene, MLF2, which contains an open reading frame of 744 bp encoding a 248-amino-acid protein highly related to the previously identified MLF1 protein (63% similarity, 40% identity). In contrast to the tissue-restricted expression pattern of MLF1, the MLF2 messenger RNA is expressed ubiquitously. The MLF2 gene locus was mapped by fluorescence in situ hybridization to human chromosome 12p13, a chromosomal region frequently involved in translocations and deletions in acute leukemias of lymphoid or myeloid lineage. In a physical map of chromosome 12, MLF2 was found to reside on the yeast artificial chromosome clone 765b9. Southern blotting analysis of malignant cell DNAs prepared from a series of acute lymphoblastic leukemia cases with translocations involving chromosome arm 12p, as well as a group of acute myeloid leukemias with various cytogenetic abnormalities, failed to reveal MLF2 gene rearrangements.

Lambda Red recombinase-mediated integration of the high molecular weight DNA into the Escherichia coli chromosome.

PubMed

Juhas, Mario; Ajioka, James W

2016-10-05

Escherichia coli K-12 is a frequently used host for a number of synthetic biology and biotechnology applications and chassis for the development of the minimal cell factories. Novel approaches for integrating high molecular weight DNA into the E. coli chromosome would therefore greatly facilitate engineering efforts in this bacterium. We developed a reliable and flexible lambda Red recombinase-based system, which utilizes overlapping DNA fragments for integration of the high molecular weight DNA into the E. coli chromosome. Our chromosomal integration strategy can be used to integrate high molecular weight DNA of variable length into any non-essential locus in the E. coli chromosome. Using this approach we integrated 15 kb DNA encoding sucrose catabolism and lactose metabolism and transport operons into the fliK locus of the flagellar region 3b in the E. coli K12 MG1655 chromosome. Furthermore, with this system we integrated 50 kb of Bacillus subtilis 168 DNA into two target sites in the E. coli K12 MG1655 chromosome. The chromosomal integrations into the fliK locus occurred with high efficiency, inhibited motility, and did not have a negative effect on the growth of E. coli. In addition to the rational design of synthetic biology devices, our high molecular weight DNA chromosomal integration system will facilitate metabolic and genome-scale engineering of E. coli.

Fine organization of genomic regions tagged to the 5S rDNA locus of the bread wheat 5B chromosome.

PubMed

Sergeeva, Ekaterina M; Shcherban, Andrey B; Adonina, Irina G; Nesterov, Michail A; Beletsky, Alexey V; Rakitin, Andrey L; Mardanov, Andrey V; Ravin, Nikolai V; Salina, Elena A

2017-11-14

The multigene family encoding the 5S rRNA, one of the most important structurally-functional part of the large ribosomal subunit, is an obligate component of all eukaryotic genomes. 5S rDNA has long been a favored target for cytological and phylogenetic studies due to the inherent peculiarities of its structural organization, such as the tandem arrays of repetitive units and their high interspecific divergence. The complex polyploid nature of the genome of bread wheat, Triticum aestivum, and the technically difficult task of sequencing clusters of tandem repeats mean that the detailed organization of extended genomic regions containing 5S rRNA genes remains unclear. This is despite the recent progress made in wheat genomic sequencing. Using pyrosequencing of BAC clones, in this work we studied the organization of two distinct 5S rDNA-tagged regions of the 5BS chromosome of bread wheat. Three BAC-clones containing 5S rDNA were identified in the 5BS chromosome-specific BAC-library of Triticum aestivum. Using the results of pyrosequencing and assembling, we obtained six 5S rDNA- containing contigs with a total length of 140,417 bp, and two sets (pools) of individual 5S rDNA sequences belonging to separate, but closely located genomic regions on the 5BS chromosome. Both regions are characterized by the presence of approximately 70-80 copies of 5S rDNA, however, they are completely different in their structural organization. The first region contained highly diverged short-type 5S rDNA units that were disrupted by multiple insertions of transposable elements. The second region contained the more conserved long-type 5S rDNA, organized as a single tandem array. FISH using probes specific to both 5S rDNA unit types showed differences in the distribution and intensity of signals on the chromosomes of polyploid wheat species and their diploid progenitors. A detailed structural organization of two closely located 5S rDNA-tagged genomic regions on the 5BS chromosome of bread wheat has been established. These two regions differ in the organization of both 5S rDNA and the neighboring sequences comprised of transposable elements, implying different modes of evolution for these regions.

Structure, tissue distribution, and chromosomal localization of the prepronociceptin gene.

PubMed

Mollereau, C; Simons, M J; Soularue, P; Liners, F; Vassart, G; Meunier, J C; Parmentier, M

1996-08-06

Nociceptin (orphanin FQ), the newly discovered natural agonist of opioid receptor-like (ORL1) receptor, is a neuropeptide that is endowed with pronociceptive activity in vivo. Nociceptin is derived from a larger precursor, prepronociceptin (PPNOC), whose human, mouse, and rat genes we have now isolated. The PPNOC gene is highly conserved in the three species and displays organizational features that are strikingly similar to those of the genes of preproenkephalin, preprodynorphin, and preproopiomelanocortin, the precursors to endogenous opioid peptides, suggesting the four genes belong to the same family-i.e., have a common evolutionary origin. The PPNOC gene encodes a single copy of nociceptin as well as of other peptides whose sequence is strictly conserved across murine and human species; hence it is likely to be neurophysiologically significant. Northern blot analysis shows that the PPNOC gene is predominantly transcribed in the central nervous system (brain and spinal cord) and, albeit weakly, in the ovary, the sole peripheral organ expressing the gene. By using a radiation hybrid cell line panel, the PPNOC gene was mapped to the short arm of human chromosome 8 (8p21), between sequence-tagged site markers WI-5833 and WI-1172, in close proximity of the locus encoding the neurofilament light chain NEFL. Analysis of yeast artificial chromosome clones belonging to the WC8.4 contig covering the 8p21 region did not allow to detect the presence of the gene on these yeast artificial chromosomes, suggesting a gap in the coverage within this contig.

Mutations in genes encoding condensin complex proteins cause microcephaly through decatenation failure at mitosis

PubMed Central

Martin, Carol-Anne; Murray, Jennie E.; Carroll, Paula; Leitch, Andrea; Mackenzie, Karen J.; Halachev, Mihail; Fetit, Ahmed E.; Keith, Charlotte; Bicknell, Louise S.; Fluteau, Adeline; Gautier, Philippe; Hall, Emma A.; Joss, Shelagh; Soares, Gabriela; Silva, João; Bober, Michael B.; Duker, Angela; Wise, Carol A.; Quigley, Alan J.; Phadke, Shubha R.; Wood, Andrew J.; Vagnarelli, Paola; Jackson, Andrew P.

2016-01-01

Compaction of chromosomes is essential for accurate segregation of the genome during mitosis. In vertebrates, two condensin complexes ensure timely chromosome condensation, sister chromatid disentanglement, and maintenance of mitotic chromosome structure. Here, we report that biallelic mutations in NCAPD2, NCAPH, or NCAPD3, encoding subunits of these complexes, cause microcephaly. In addition, hypomorphic Ncaph2 mice have significantly reduced brain size, with frequent anaphase chromatin bridge formation observed in apical neural progenitors during neurogenesis. Such DNA bridges also arise in condensin-deficient patient cells, where they are the consequence of failed sister chromatid disentanglement during chromosome compaction. This results in chromosome segregation errors, leading to micronucleus formation and increased aneuploidy in daughter cells. These findings establish “condensinopathies” as microcephalic disorders, with decatenation failure as an additional disease mechanism for microcephaly, implicating mitotic chromosome condensation as a key process ensuring mammalian cerebral cortex size. PMID:27737959

Toxin-Antitoxin Systems in the Mobile Genome of Acidithiobacillus ferrooxidans

PubMed Central

Bustamante, Paula; Tello, Mario; Orellana, Omar

2014-01-01

Toxin-antitoxin (TA) systems are genetic modules composed of a pair of genes encoding a stable toxin and an unstable antitoxin that inhibits toxin activity. They are widespread among plasmids and chromosomes of bacteria and archaea. TA systems are known to be involved in the stabilization of plasmids but there is no consensus about the function of chromosomal TA systems. To shed light on the role of chromosomally encoded TA systems we analyzed the distribution and functionality of type II TA systems in the chromosome of two strains from Acidithiobacillus ferrooxidans (ATCC 23270 and 53993), a Gram-negative, acidophilic, environmental bacterium that participates in the bioleaching of minerals. As in other environmental microorganisms, A. ferrooxidans has a high content of TA systems (28-29) and in twenty of them the toxin is a putative ribonuclease. According to the genetic context, some of these systems are encoded near or within mobile genetic elements. Although most TA systems are shared by both strains, four of them, which are encoded in the active mobile element ICEAfe1, are exclusive to the type strain ATCC 23270. We demostrated that two TA systems from ICEAfe1 are functional in E. coli cells, since the toxins inhibit growth and the antitoxins counteract the effect of their cognate toxins. All the toxins from ICEAfe1, including a novel toxin, are RNases with different ion requirements. The data indicate that some of the chromosomally encoded TA systems are actually part of the A. ferrooxidans mobile genome and we propose that could be involved in the maintenance of these integrated mobile genetic elements. PMID:25384039

Linkage of genes for laminin B1 and B2 subunits on chromosome 1 in mouse.

PubMed

Elliott, R W; Barlow, D; Hogan, B L

1985-08-01

We have used cDNA clones for the B1 and B2 subunits of laminin to find restriction fragment length DNA polymorphisms for the genes encoding these polypeptides in the mouse. Three alleles were found for LamB2 and two for LamB1 among the inbred mouse strains. The segregation of these polymorphisms among recombinant inbred strains showed that these genes are tightly linked in the central region of mouse Chromosome 1 between Sas-1 and Ly-m22, 7.4 +/- 3.2 cM distal to the Pep-3 locus. There is no evidence in the mouse for pseudogenes for these proteins.

The Landscape of Somatic Chromosomal Copy Number Aberrations in GEM Models of Prostate Carcinoma

PubMed Central

Bianchi-Frias, Daniella; Hernandez, Susana A.; Coleman, Roger; Wu, Hong; Nelson, Peter S.

2015-01-01

Human prostate cancer (PCa) is known to harbor recurrent genomic aberrations consisting of chromosomal losses, gains, rearrangements and mutations that involve oncogenes and tumor suppressors. Genetically engineered mouse (GEM) models have been constructed to assess the causal role of these putative oncogenic events and provide molecular insight into disease pathogenesis. While GEM models generally initiate neoplasia by manipulating a single gene, expression profiles of GEM tumors typically comprise hundreds of transcript alterations. It is unclear whether these transcriptional changes represent the pleiotropic effects of single oncogenes, and/or cooperating genomic or epigenomic events. Therefore, it was determined if structural chromosomal alterations occur in GEM models of PCa and whether the changes are concordant with human carcinomas. Whole genome array-based comparative genomic hybridization (CGH) was used to identify somatic chromosomal copy number aberrations (SCNAs) in the widely used TRAMP, Hi-Myc, Pten-null and LADY GEM models. Interestingly, very few SCNAs were identified and the genomic architecture of Hi-Myc, Pten-null and LADY tumors were essentially identical to the germline. TRAMP neuroendocrine carcinomas contained SCNAs, which comprised three recurrent aberrations including a single copy loss of chromosome 19 (encoding Pten). In contrast, cell lines derived from the TRAMP, Hi-Myc, and Pten-null tumors were notable for numerous SCNAs that included copy gains of chromosome 15 (encoding Myc) and losses of chromosome 11 (encoding p53). PMID:25298407

Decoding the disease-associated proteins encoded in the human chromosome 4.

PubMed

Chen, Lien-Chin; Liu, Mei-Ying; Hsiao, Yung-Chin; Choong, Wai-Kok; Wu, Hsin-Yi; Hsu, Wen-Lian; Liao, Pao-Chi; Sung, Ting-Yi; Tsai, Shih-Feng; Yu, Jau-Song; Chen, Yu-Ju

2013-01-04

Chromosome 4 is the fourth largest chromosome, containing approximately 191 megabases (~6.4% of the human genome) with 757 protein-coding genes. A number of marker genes for many diseases have been found in this chromosome, including genetic diseases (e.g., hepatocellular carcinoma) and biomedical research (cardiac system, aging, metabolic disorders, immune system, cancer and stem cell) related genes (e.g., oncogenes, growth factors). As a pilot study for the chromosome 4-centric human proteome project (Chr 4-HPP), we present here a systematic analysis of the disease association, protein isoforms, coding single nucleotide polymorphisms of these 757 protein-coding genes and their experimental evidence at the protein level. We also describe how the findings from the chromosome 4 project might be used to drive the biomarker discovery and validation study in disease-oriented projects, using the examples of secretomic and membrane proteomic approaches in cancer research. By integrating with cancer cell secretomes and several other existing databases in the public domain, we identified 141 chromosome 4-encoded proteins as cancer cell-secretable/shedable proteins. Additionally, we also identified 54 chromosome 4-encoded proteins that have been classified as cancer-associated proteins with successful selected or multiple reaction monitoring (SRM/MRM) assays developed. From literature annotation and topology analysis, 271 proteins were recognized as membrane proteins while 27.9% of the 757 proteins do not have any experimental evidence at the protein-level. In summary, the analysis revealed that the chromosome 4 is a rich resource for cancer-associated proteins for biomarker verification projects and for drug target discovery projects.

Organization of the human gene for nucleobindin (NUC) and its chromosomal assignment to 19q13.2-q13.4

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

Miura, Keiji; Kurosawa, Yoshikazu; Hirai, Momoki

1996-06-01

Nucleobindin (Nuc) was first identified as a secreted protein of 55 kDa that promotes production of DNA-specific antibodies in lupus-prone MRL/lpr mice. Analysis of cDNA that encoded Nuc revealed that the protein is composed of a signal peptide, a DNA-binding site, two calcium-binding motifs (EF-hand motifs), and a leucine zipper. In the present study, we analysed the organization of the human gene for Nuc (NUC). It consists of 13 exons that are distributed in a region of 32 kb. The functional motifs listed above are encoded in corresponding exons. NUC was expressed in all organs examined. Comparison of nucleotide sequencesmore » in the promotre regions between human and mouse NCU genes revealed several conserved sequences. Among them, two Sp1-binding sites and a CCAAT box are of particular interest. The promoter is of the TATA-less type, and transcription starts at multiple sites in both the human and the mouse genes. These features suggest that NUC might normally play a role as a housekeeping gene. NUC was located at human chromosome 19q13.2-q13.4. 25 refs., 4 figs., 1 tab.« less

Characterization of a Spontaneous Nonmagnetic Mutant of Magnetospirillum gryphiswaldense Reveals a Large Deletion Comprising a Putative Magnetosome Island

PubMed Central

Schübbe, Sabrina; Kube, Michael; Scheffel, André; Wawer, Cathrin; Heyen, Udo; Meyerdierks, Anke; Madkour, Mohamed H.; Mayer, Frank; Reinhardt, Richard; Schüler, Dirk

2003-01-01

Frequent spontaneous loss of the magnetic phenotype was observed in stationary-phase cultures of the magnetotactic bacterium Magnetospirillum gryphiswaldense MSR-1. A nonmagnetic mutant, designated strain MSR-1B, was isolated and characterized. The mutant lacked any structures resembling magnetosome crystals as well as internal membrane vesicles. The growth of strain MSR-1B was impaired under all growth conditions tested, and the uptake and accumulation of iron were drastically reduced under iron-replete conditions. A large chromosomal deletion of approximately 80 kb was identified in strain MSR-1B, which comprised both the entire mamAB and mamDC clusters as well as further putative operons encoding a number of magnetosome-associated proteins. A bacterial artificial chromosome clone partially covering the deleted region was isolated from the genomic library of wild-type M. gryphiswaldense. Sequence analysis of this fragment revealed that all previously identified mam genes were closely linked with genes encoding other magnetosome-associated proteins within less than 35 kb. In addition, this region was remarkably rich in insertion elements and harbored a considerable number of unknown gene families which appeared to be specific for magnetotactic bacteria. Overall, these findings suggest the existence of a putative large magnetosome island in M. gryphiswaldense and other magnetotactic bacteria. PMID:13129949

Sequence and analysis of chromosome 4 of the plant Arabidopsis thaliana.

PubMed

Mayer, K; Schüller, C; Wambutt, R; Murphy, G; Volckaert, G; Pohl, T; Düsterhöft, A; Stiekema, W; Entian, K D; Terryn, N; Harris, B; Ansorge, W; Brandt, P; Grivell, L; Rieger, M; Weichselgartner, M; de Simone, V; Obermaier, B; Mache, R; Müller, M; Kreis, M; Delseny, M; Puigdomenech, P; Watson, M; Schmidtheini, T; Reichert, B; Portatelle, D; Perez-Alonso, M; Boutry, M; Bancroft, I; Vos, P; Hoheisel, J; Zimmermann, W; Wedler, H; Ridley, P; Langham, S A; McCullagh, B; Bilham, L; Robben, J; Van der Schueren, J; Grymonprez, B; Chuang, Y J; Vandenbussche, F; Braeken, M; Weltjens, I; Voet, M; Bastiaens, I; Aert, R; Defoor, E; Weitzenegger, T; Bothe, G; Ramsperger, U; Hilbert, H; Braun, M; Holzer, E; Brandt, A; Peters, S; van Staveren, M; Dirske, W; Mooijman, P; Klein Lankhorst, R; Rose, M; Hauf, J; Kötter, P; Berneiser, S; Hempel, S; Feldpausch, M; Lamberth, S; Van den Daele, H; De Keyser, A; Buysshaert, C; Gielen, J; Villarroel, R; De Clercq, R; Van Montagu, M; Rogers, J; Cronin, A; Quail, M; Bray-Allen, S; Clark, L; Doggett, J; Hall, S; Kay, M; Lennard, N; McLay, K; Mayes, R; Pettett, A; Rajandream, M A; Lyne, M; Benes, V; Rechmann, S; Borkova, D; Blöcker, H; Scharfe, M; Grimm, M; Löhnert, T H; Dose, S; de Haan, M; Maarse, A; Schäfer, M; Müller-Auer, S; Gabel, C; Fuchs, M; Fartmann, B; Granderath, K; Dauner, D; Herzl, A; Neumann, S; Argiriou, A; Vitale, D; Liguori, R; Piravandi, E; Massenet, O; Quigley, F; Clabauld, G; Mündlein, A; Felber, R; Schnabl, S; Hiller, R; Schmidt, W; Lecharny, A; Aubourg, S; Chefdor, F; Cooke, R; Berger, C; Montfort, A; Casacuberta, E; Gibbons, T; Weber, N; Vandenbol, M; Bargues, M; Terol, J; Torres, A; Perez-Perez, A; Purnelle, B; Bent, E; Johnson, S; Tacon, D; Jesse, T; Heijnen, L; Schwarz, S; Scholler, P; Heber, S; Francs, P; Bielke, C; Frishman, D; Haase, D; Lemcke, K; Mewes, H W; Stocker, S; Zaccaria, P; Bevan, M; Wilson, R K; de la Bastide, M; Habermann, K; Parnell, L; Dedhia, N; Gnoj, L; Schutz, K; Huang, E; Spiegel, L; Sehkon, M; Murray, J; Sheet, P; Cordes, M; Abu-Threideh, J; Stoneking, T; Kalicki, J; Graves, T; Harmon, G; Edwards, J; Latreille, P; Courtney, L; Cloud, J; Abbott, A; Scott, K; Johnson, D; Minx, P; Bentley, D; Fulton, B; Miller, N; Greco, T; Kemp, K; Kramer, J; Fulton, L; Mardis, E; Dante, M; Pepin, K; Hillier, L; Nelson, J; Spieth, J; Ryan, E; Andrews, S; Geisel, C; Layman, D; Du, H; Ali, J; Berghoff, A; Jones, K; Drone, K; Cotton, M; Joshu, C; Antonoiu, B; Zidanic, M; Strong, C; Sun, H; Lamar, B; Yordan, C; Ma, P; Zhong, J; Preston, R; Vil, D; Shekher, M; Matero, A; Shah, R; Swaby, I K; O'Shaughnessy, A; Rodriguez, M; Hoffmann, J; Till, S; Granat, S; Shohdy, N; Hasegawa, A; Hameed, A; Lodhi, M; Johnson, A; Chen, E; Marra, M; Martienssen, R; McCombie, W R

1999-12-16

The higher plant Arabidopsis thaliana (Arabidopsis) is an important model for identifying plant genes and determining their function. To assist biological investigations and to define chromosome structure, a coordinated effort to sequence the Arabidopsis genome was initiated in late 1996. Here we report one of the first milestones of this project, the sequence of chromosome 4. Analysis of 17.38 megabases of unique sequence, representing about 17% of the genome, reveals 3,744 protein coding genes, 81 transfer RNAs and numerous repeat elements. Heterochromatic regions surrounding the putative centromere, which has not yet been completely sequenced, are characterized by an increased frequency of a variety of repeats, new repeats, reduced recombination, lowered gene density and lowered gene expression. Roughly 60% of the predicted protein-coding genes have been functionally characterized on the basis of their homology to known genes. Many genes encode predicted proteins that are homologous to human and Caenorhabditis elegans proteins.

The active gene that encodes human High Mobility Group 1 protein (HMG1) contains introns and maps to chromosome 13

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

Ferrari, S.; Finelli, P.; Rocchi, M.

The human genome contains a large number of sequences related to the cDNA for High Mobility Group 1 protein (HMG1), which so far has hampered the cloning and mapping of the active HMG1 gene. We show that the human HMG1 gene contains introns, while the HMG1-related sequences do not and most likely are retrotransposed pseudogenes. We identified eight YACs from the ICI and CEPH libraries that contain the human HMG1 gene. The HMG1 gene is similar in structure to the previously characterized murine homologue and maps to human chromosome 13 and q12, as determined by in situ hybridization. The mousemore » Hmg1 gene maps to the telomeric region of murine Chromosome 5, which is syntenic to the human 13q12 band. 18 refs., 3 figs.« less

Candidate chromosome 1 disease susceptibility genes for Sjogren’s syndrome xerostomia are narrowed by novel NOD.B10 congenic mice

PubMed Central

Mongini, Patricia K. A.; Kramer, Jill M.; Ishikawa, Tomo-o; Herschman, Harvey; Esposito, Donna

2014-01-01

Sjogren’s syndrome (SS) is characterized by salivary gland leukocytic infiltrates and impaired salivation (xerostomia). Cox-2 (Ptgs2) is located on chromosome 1 within the span of the Aec2 region. In an attempt to demonstrate that COX-2 drives antibody-dependent hyposalivation, NOD.B10 congenic mice bearing a Cox-2flox gene were generated. A congenic line with non-NOD alleles in Cox-2-flanking genes failed manifest xerostomia. Further backcrossing yielded disease-susceptible NOD.B10 Cox-2flox lines; fine genetic mapping determined that critical Aec2 genes lie within a 1.56 to 2.17 Mb span of DNA downstream of Cox-2. Bioinformatics analysis revealed that susceptible and non-susceptible lines exhibit non-synonymous coding SNPs in 8 protein-encoding genes of this region, thereby better delineating candidate Aec2 alleles needed for SS xerostomia. PMID:24685748

Genome-wide association study of plasma polyunsaturated fatty acids in the InCHIANTI Study.

PubMed

Tanaka, Toshiko; Shen, Jian; Abecasis, Gonçalo R; Kisialiou, Aliaksei; Ordovas, Jose M; Guralnik, Jack M; Singleton, Andrew; Bandinelli, Stefania; Cherubini, Antonio; Arnett, Donna; Tsai, Michael Y; Ferrucci, Luigi

2009-01-01

Polyunsaturated fatty acids (PUFA) have a role in many physiological processes, including energy production, modulation of inflammation, and maintenance of cell membrane integrity. High plasma PUFA concentrations have been shown to have beneficial effects on cardiovascular disease and mortality. To identify genetic contributors of plasma PUFA concentrations, we conducted a genome-wide association study of plasma levels of six omega-3 and omega-6 fatty acids in 1,075 participants in the InCHIANTI study on aging. The strongest evidence for association was observed in a region of chromosome 11 that encodes three fatty acid desaturases (FADS1, FADS2, FADS3). The SNP with the most significant association was rs174537 near FADS1 in the analysis of arachidonic acid (AA; p = 5.95 x 10(-46)). Minor allele homozygotes had lower AA compared to the major allele homozygotes and rs174537 accounted for 18.6% of the additive variance in AA concentrations. This SNP was also associated with levels of eicosadienoic acid (EDA; p = 6.78 x 10(-9)) and eicosapentanoic acid (EPA; p = 1.07 x 10(-14)). Participants carrying the allele associated with higher AA, EDA, and EPA also had higher low-density lipoprotein (LDL-C) and total cholesterol levels. Outside the FADS gene cluster, the strongest region of association mapped to chromosome 6 in the region encoding an elongase of very long fatty acids 2 (ELOVL2). In this region, association was observed with EPA (rs953413; p = 1.1 x 10(-6)). The effects of rs174537 were confirmed in an independent sample of 1,076 subjects participating in the GOLDN study. The ELOVL2 SNP was associated with docosapentanoic and DHA but not with EPA in GOLDN. These findings show that polymorphisms of genes encoding enzymes in the metabolism of PUFA contribute to plasma concentrations of fatty acids.

A fresh look at the male-specific region of the human Y chromosome.

PubMed

Jangravi, Zohreh; Alikhani, Mehdi; Arefnezhad, Babak; Sharifi Tabar, Mehdi; Taleahmad, Sara; Karamzadeh, Razieh; Jadaliha, Mahdieh; Mousavi, Seyed Ahmad; Ahmadi Rastegar, Diba; Parsamatin, Pouria; Vakilian, Haghighat; Mirshahvaladi, Shahab; Sabbaghian, Marjan; Mohseni Meybodi, Anahita; Mirzaei, Mehdi; Shahhoseini, Maryam; Ebrahimi, Marzieh; Piryaei, Abbas; Moosavi-Movahedi, Ali Akbar; Haynes, Paul A; Goodchild, Ann K; Nasr-Esfahani, Mohammad Hossein; Jabbari, Esmaiel; Baharvand, Hossein; Sedighi Gilani, Mohammad Ali; Gourabi, Hamid; Salekdeh, Ghasem Hosseini

2013-01-04

The Chromosome-centric Human Proteome Project (C-HPP) aims to systematically map the entire human proteome with the intent to enhance our understanding of human biology at the cellular level. This project attempts simultaneously to establish a sound basis for the development of diagnostic, prognostic, therapeutic, and preventive medical applications. In Iran, current efforts focus on mapping the proteome of the human Y chromosome. The male-specific region of the Y chromosome (MSY) is unique in many aspects and comprises 95% of the chromosome's length. The MSY continually retains its haploid state and is full of repeated sequences. It is responsible for important biological roles such as sex determination and male fertility. Here, we present the most recent update of MSY protein-encoding genes and their association with various traits and diseases including sex determination and reversal, spermatogenesis and male infertility, cancers such as prostate cancers, sex-specific effects on the brain and behavior, and graft-versus-host disease. We also present information available from RNA sequencing, protein-protein interaction, post-translational modification of MSY protein-coding genes and their implications in biological systems. An overview of Human Y chromosome Proteome Project is presented and a systematic approach is suggested to ensure that at least one of each predicted protein-coding gene's major representative proteins will be characterized in the context of its major anatomical sites of expression, its abundance, and its functional relevance in a biological and/or medical context. There are many technical and biological issues that will need to be overcome in order to accomplish the full scale mapping.

A tumor suppressor locus within 3p14-p12 mediates rapid cell death of renal cell carcinoma in vivo.

PubMed Central

Sanchez, Y; el-Naggar, A; Pathak, S; Killary, A M

1994-01-01

High frequency loss of alleles and cytogenetic aberrations on the short arm of chromosome 3 have been documented in renal cell carcinoma (RCC). Potentially, three distinct regions on 3p could encode tumor suppressor genes involved in the genesis of this cancer. We report that the introduction of a centric fragment of 3p, encompassing 3p14-q11, into a highly malignant RCC cell line resulted in a dramatic suppression of tumor growth in athymic nude mice. Another defined deletion hybrid contained the region 3p12-q24 of the introduced human chromosome and failed to suppress tumorigenicity. These data functionally define a tumor suppressor locus, nonpapillary renal carcinoma-1 (NRC-1), within 3p14-p12, the most proximal region of high frequency allele loss in sporadic RCC as well as the region containing the translocation breakpoint in familial RCC. Furthermore, we provide functional evidence that NRC-1 controls the growth of RCC cells by inducing rapid cell death in vivo. Images PMID:8159756

A complete YAC contig of the Prader-Willi/Angelman chromosome region (15q11-q13) and refined localization of the SNRPN gene

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

Mutirangura, A.; Jayakumar, A.; Sutcliffe, J.S.

1993-12-01

Since a previous report of a partial YAC contig of the Prader-Willi/Angelman chromosome region (15q11-q13), a complete contig spanning approximately 3.5 Mb has been developed. YACs were isolated from two human genomic libraries by PCR and hybridization screening methods. Twenty-three sequence-tagged sites (STSs) were mapped within the contig, a density of [approximately]1 per 200 kb. Overlaps between YAC clones were identified by Alu-PCR dot-blot analysis and confirmed by STS mapping or hybridization with ends of YAC inserts. The gene encoding small nuclear ribonucleoprotein-associated peptide N (SNRPN), recently identified as a candidate gene for Prader-Willi syndrome, was localized within this contigmore » between markers PW71 and TD3-21. Loci mapped within and immediately flanking the Prader-Willi/Angelman chromosome region contig are ordered as follows: cen-IR39-ML34-IR4-3R-TD189-1-PW71-SNRPN-TD3-21-LS6-1-GABRB3,D15S97-GABRA5-IR10-1-CMW1-tel. This YAC contig will be a useful resource for more detailed physical mapping of the region, for generation of new DNA markers, and for mapping or cloning candidate genes for the Prader-Willi and Angelman syndromes. 36 refs., 2 figs., 2 tabs.« less

Genetic and radiation hybrid mapping of the hyperekplexia region on chromosome 5q.

PubMed Central

Ryan, S G; Dixon, M J; Nigro, M A; Kelts, K A; Markand, O N; Terry, J C; Shiang, R; Wasmuth, J J; O'Connell, P

1992-01-01

Hyperekplexia, or startle disease (STHE), is an autosomal dominant neurologic disorder characterized by muscular rigidity of central nervous system origin, particularly in the neonatal period, and by an exaggerated startle response to sudden, unexpected acoustic or tactile stimuli. STHE responds dramatically to the benzodiazepine drug clonazepam, which acts at gamma-aminobutyric acid type A (GABA-A) receptors. The STHE locus (STHE) was recently assigned to chromosome 5q, on the basis of tight linkage to the colony-stimulating factor 1-receptor (CSF1-R) locus in a single large family. We performed linkage analysis in the original and three additional STHE pedigrees with eight chromosome 5q microsatellite markers and placed several of the most closely linked markers on an existing radiation hybrid (RH) map of the region. The results provide strong evidence for genetic locus homogeneity and assign STHE to a 5.9-cM interval defined by CSF1-R and D5S379, which are separated by an RH map distance of 74 centirays (roughly 2.2-3.7 Mb). Two polymorphic markers (D5S119 and D5S209) lie within this region, but they could not be ordered with respect to STHE. RH mapping eliminated the candidate genes GABRA1 and GABRG2, which encode GABA-A receptor components, by showing that they are telomeric to the target region. PMID:1334371

Chromosomal features of Escherichia coli serotype O2:K2, an avian pathogenic E. coli.

PubMed

Jørgensen, Steffen L; Kudirkiene, Egle; Li, Lili; Christensen, Jens P; Olsen, John E; Nolan, Lisa; Olsen, Rikke H

2017-01-01

Escherichia coli causing infection outside the gastrointestinal system are referred to as extra-intestinal pathogenic E. coli. Avian pathogenic E. coli is a subgroup of extra-intestinal pathogenic E. coli and infections due to avian pathogenic E. coli have major impact on poultry production economy and welfare worldwide. An almost defining characteristic of avian pathogenic E. coli is the carriage of plasmids, which may encode virulence factors and antibiotic resistance determinates. For the same reason, plasmids of avian pathogenic E. coli have been intensively studied. However, genes encoded by the chromosome may also be important for disease manifestation and antimicrobial resistance. For the E. coli strain APEC_O2 the plasmids have been sequenced and analyzed in several studies, and E. coli APEC_O2 may therefore serve as a reference strain in future studies. Here we describe the chromosomal features of E. coli APEC_O2. E. coli APEC_O2 is a sequence type ST135, has a chromosome of 4,908,820 bp (plasmid removed), comprising 4672 protein-coding genes, 110 RNA genes, and 156 pseudogenes, with an average G + C content of 50.69%. We identified 82 insertion sequences as well as 4672 protein coding sequences, 12 predicated genomic islands, three prophage-related sequences, and two clustered regularly interspaced short palindromic repeats regions on the chromosome, suggesting the possible occurrence of horizontal gene transfer in this strain. The wildtype strain of E. coli APEC_O2 is resistant towards multiple antimicrobials, however, no (complete) antibiotic resistance genes were present on the chromosome, but a number of genes associated with extra-intestinal disease were identified. Together, the information provided here on E. coli APEC_O2 will assist in future studies of avian pathogenic E. coli strains, in particular regarding strain of E. coli APEC_O2, and aid in the general understanding of the pathogenesis of avian pathogenic E. coli .

Association of late-onset Alzheimer disease with a genotype of PLAU, the gene encoding urokinase-type plasminogen activator on chromosome 10q22.2.

PubMed

Finckh, U; van Hadeln, K; Müller-Thomsen, T; Alberici, A; Binetti, G; Hock, C; Nitsch, R M; Stoppe, G; Reiss, J; Gal, A

2003-08-01

Urokinase-type plasminogen activator (uPA) converts plasminogen to plasmin. Plasmin is involved in processing of amyloid precursor protein and degrades secreted and aggregated amyloid-beta, a hallmark of Alzheimer disease (AD). PLAU, the gene encoding uPA, maps to chromosome 10q22.2 between two regions showing linkage to late-onset AD (LOAD). We genotyped a frequent C/T single nucleotide polymorphism in codon 141 of PLAU (P141L) in 347 patients with LOAD and 291 control subjects. LOAD was associated with homozygous C/C PLAU genotype in the whole sample (chi2=15.7, P=0.00039, df 2), as well as in all sub-samples stratified by gender or APOE epsilon4 carrier status (chi2> or = 6.84, P< or =0.033, df 2). Odds ratio for LOAD due to homozygosity C/C was 1.89 (95% confidence interval 1.37-2.61). PLAU is a promising new candidate gene for LOAD, with allele C (P141) being a recessive risk allele or allele T (L141) conferring protection.

Preferential recruitment of the maternal centromere-specific histone H3 (CENH3) in oat (Avena sativa L.) × pearl millet (Pennisetum glaucum L.) hybrid embryos.

PubMed

Ishii, Takayoshi; Sunamura, Naohiro; Matsumoto, Ayaka; Eltayeb, Amin Elsadig; Tsujimoto, Hisashi

2015-12-01

Chromosome elimination occurs frequently in interspecific hybrids between distantly related species in Poaceae. However, chromosomes from both parents behave stably in a hybrid of female oat (Avena sativa L.) pollinated by pearl millet (Pennisetum glaucum L.). To analyze the chromosome behavior in this hybrid, we cloned the centromere-specific histone H3 (CENH3) genes of oat and pearl millet and produced a pearl millet-specific anti-CENH3 antibody. Application of this antibody together with a grass species common anti-CENH3 antibody revealed the dynamic CENH3 composition of the hybrid cells before and after fertilization. Despite co-expression of CENH3 genes encoded by oat and pearl millet, only an oat-type CENH3 was incorporated into the centromeres of both species in the hybrid embryo. Oat CENH3 enables a functional centromere in pearl millet chromosomes in an oat genetic background. Comparison of CENH3 genes among Poaceae species that show chromosome elimination in interspecific hybrids revealed that the loop 1 regions of oat and pearl millet CENH3 exhibit exceptionally high similarity.

Scc2 regulates gene expression by recruiting cohesin to the chromosome as a transcriptional activator during yeast meiosis

PubMed Central

Lin, Weiqiang; Jin, Hui; Liu, Xiuwen; Hampton, Kristin; Yu, Hong-Guo

2011-01-01

To tether sister chromatids, a protein-loading complex, including Scc2, recruits cohesin to the chromosome at discrete loci. Cohesin facilitates the formation of a higher-order chromosome structure that could also influence gene expression. How cohesin directly regulates transcription remains to be further elucidated. We report that in budding yeast Scc2 is required for sister-chromatid cohesion during meiosis for two reasons. First, Scc2 is required for activating the expression of REC8, which encodes a meiosis-specific cohesin subunit; second, Scc2 is necessary for recruiting meiotic cohesin to the chromosome to generate sister-chromatid cohesion. Using a heterologous reporter assay, we have found that Scc2 increases the activity of its target promoters by recruiting cohesin to establish an upstream cohesin-associated region in a position-dependent manner. Rec8-associated meiotic cohesin is required for the full activation of the REC8 promoter, revealing that cohesin has a positive feedback on transcriptional regulation. Finally, we provide evidence that chromosomal binding of cohesin is sufficient for target-gene activation during meiosis. Our data support a noncanonical role for cohesin as a transcriptional activator during cell differentiation. PMID:21508318

Mutations in genes encoding condensin complex proteins cause microcephaly through decatenation failure at mitosis.

PubMed

Martin, Carol-Anne; Murray, Jennie E; Carroll, Paula; Leitch, Andrea; Mackenzie, Karen J; Halachev, Mihail; Fetit, Ahmed E; Keith, Charlotte; Bicknell, Louise S; Fluteau, Adeline; Gautier, Philippe; Hall, Emma A; Joss, Shelagh; Soares, Gabriela; Silva, João; Bober, Michael B; Duker, Angela; Wise, Carol A; Quigley, Alan J; Phadke, Shubha R; Wood, Andrew J; Vagnarelli, Paola; Jackson, Andrew P

2016-10-01

Compaction of chromosomes is essential for accurate segregation of the genome during mitosis. In vertebrates, two condensin complexes ensure timely chromosome condensation, sister chromatid disentanglement, and maintenance of mitotic chromosome structure. Here, we report that biallelic mutations in NCAPD2, NCAPH, or NCAPD3, encoding subunits of these complexes, cause microcephaly. In addition, hypomorphic Ncaph2 mice have significantly reduced brain size, with frequent anaphase chromatin bridge formation observed in apical neural progenitors during neurogenesis. Such DNA bridges also arise in condensin-deficient patient cells, where they are the consequence of failed sister chromatid disentanglement during chromosome compaction. This results in chromosome segregation errors, leading to micronucleus formation and increased aneuploidy in daughter cells. These findings establish "condensinopathies" as microcephalic disorders, with decatenation failure as an additional disease mechanism for microcephaly, implicating mitotic chromosome condensation as a key process ensuring mammalian cerebral cortex size. © 2016 Martin et al.; Published by Cold Spring Harbor Laboratory Press.

Gene encoding a novel extracellular metalloprotease in Bacillus subtilis.

PubMed Central

Sloma, A; Rudolph, C F; Rufo, G A; Sullivan, B J; Theriault, K A; Ally, D; Pero, J

1990-01-01

The gene for a novel extracellular metalloprotease was cloned, and its nucleotide sequence was determined. The gene (mpr) encodes a primary product of 313 amino acids that has little similarity to other known Bacillus proteases. The amino acid sequence of the mature protease was preceded by a signal sequence of approximately 34 amino acids and a pro sequence of 58 amino acids. Four cysteine residues were found in the deduced amino acid sequence of the mature protein, indicating the possible presence of disulfide bonds. The mpr gene mapped in the cysA-aroI region of the chromosome and was not required for growth or sporulation. Images FIG. 2 FIG. 7 PMID:2105291

Accelerating pathway evolution by increasing the gene dosage of chromosomal segments.

PubMed

Tumen-Velasquez, Melissa; Johnson, Christopher W; Ahmed, Alaa; Dominick, Graham; Fulk, Emily M; Khanna, Payal; Lee, Sarah A; Schmidt, Alicia L; Linger, Jeffrey G; Eiteman, Mark A; Beckham, Gregg T; Neidle, Ellen L

2018-06-18

Experimental evolution is a critical tool in many disciplines, including metabolic engineering and synthetic biology. However, current methods rely on the chance occurrence of a key step that can dramatically accelerate evolution in natural systems, namely increased gene dosage. Our studies sought to induce the targeted amplification of chromosomal segments to facilitate rapid evolution. Since increased gene dosage confers novel phenotypes and genetic redundancy, we developed a method, Evolution by Amplification and Synthetic Biology (EASy), to create tandem arrays of chromosomal regions. In Acinetobacter baylyi , EASy was demonstrated on an important bioenergy problem, the catabolism of lignin-derived aromatic compounds. The initial focus on guaiacol (2-methoxyphenol), a common lignin degradation product, led to the discovery of Amycolatopsis genes ( gcoAB ) encoding a cytochrome P450 enzyme that converts guaiacol to catechol. However, chromosomal integration of gcoAB in Pseudomonas putida or A. baylyi did not enable guaiacol to be used as the sole carbon source despite catechol being a growth substrate. In ∼1,000 generations, EASy yielded alleles that in single chromosomal copy confer growth on guaiacol. Different variants emerged, including fusions between GcoA and CatA (catechol 1,2-dioxygenase). This study illustrates the power of harnessing chromosomal gene amplification to accelerate the evolution of desirable traits.

Acquisition and amplification of a testis-expressed autosomal gene, SSL, by the Drosophila Y chromosome

PubMed Central

Kalmykova, Alla I.; Shevelyov, Yury Y.; Dobritsa, Anna A.; Gvozdev, Vladimir A.

1997-01-01

The acquisition of autosomal fertility genes has been proposed to be an important process in human Y chromosome evolution. For example, the Y-linked fertility factor DAZ (Deleted in Azoospermia) appears to have arisen after the transposition and tandem amplification of the autosomal DAZH gene. The Drosophila melanogaster Y chromosome contains tandemly repeated Su(Ste) units that are thought to affect male fertility as suppressors of the homologous X-linked Stellate repeats. Here we report the detection of a testis-expressed autosomal gene, SSL [Su(Ste)-like], that appears to be an ancestor of the Y-linked Su(Ste) units. SSL encodes a casein kinase 2 (CK2) β-subunit-like protein. Its putative ORF shares extensive (45%) homology with the genuine β-subunit of CK2 and retains the conserved C-terminal and Glu/Asp-rich domains that are essential for CK2 holoenzyme regulation. SSL maps within region 60D1–2 of D. melanogaster and D. simulans polytene chromosomes. We present evidence that SSL was derived from the genuine βCK2 gene by reverse transcription. This event resulted in the loss of the first three introns in the coding region of the SSL ancestor gene. Evolutionary analysis indicates that SSL has evolved under selective pressure at the translational level. Its sequence, especially in the 3′ region, is much closer to the Y-linked Su(Ste) tandem repeats than to the βCK2 gene. These results suggest that the acquisition of testis-specific autosomal genes may be important for the evolution of Drosophila as well as human Y chromosomes. PMID:9177211

Nested polymerase chain reaction study of 53 cases with Turner`s syndrome: Is cytogenetically undetected Y mosaicism common?

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

Binder, G.; Koch, A.; Ranke, M.B.

1995-12-01

Turner`s syndrome patients with Y mosaicism face a high risk of developing gonadoblastoma. Cytogenetic analysis can fail to detect rare cells bearing a normal or structurally abnormal Y chromosome (low level Y mosaicism). We screened 53 individuals with Turner`s syndrome for presence of sex-determining region Y (SRY), the testis-specific protein, Y encoded, gene, and the Y centromeric DYZ3 repeat using nested polymerase chain reaction (PCR). Thirty girls (57%) had the 45,X karyotype, determined through standard analysis of blood lymphocytes. The remaining 23 girls (43%) were mosaics and/or had structural abnormalities in 1 X-chromosome. Genomic DNA from blood leukocytes was amplifiedmore » using 2 rounds of PCR. This method was sensitive enough to detect 0.0001% male DNA on a female background. None of 53 Turner`s syndrome cases was positive for Y-specific loci after the first round of PCR. After the second round, 2 of 53 Turner`s syndrome cases were positive for SRY mapping to the distal short arm of chromosome Y. In 1 SRY-positive subject, the karyotype was 45,X, and in the other, it was 46,Xi(Xq). None of 53 Turner`s syndrome individuals, including the 2 SRY-positive subjects, were positive for the testis-specific protein, Y encoded, gene on the proximal short arm of chromosome Y or the centromeric DYZ3 repeat. These data exclude low level Y mosaicism in almost all Turner`s syndrome cases tested. 35 refs., 3 figs., 1 tab.« less

Electrophoretic variation in low molecular weight lens crystallins from inbred strains of rats.

PubMed

Donner, M E; Skow, L C; Kunz, H W; Gill, T J

1985-10-01

Analysis of rat lens soluble proteins by analytical isoelectric focusing detected two inherited electrophoretic differences in low molecular weight (LM) crystallins from inbred strains of rats (Rattus norvegicus). The polymorphic lens crystallins were shown to be similar to a genetically variant LM crystallin, LEN-1, previously described in mice (Mus musculus) and encoded on chromosome 1, at a locus linked to Pep-3 (dipeptidase). Linkage analysis demonstrated that the rat crystallin locus was loosely linked to Pep-3 at a recombination distance of 38 +/- 4.5 U. These data suggest the conservation of a large chromosomal region during the evolution of Rodentia and support the hypothesis that the gamma-crystallins are evolving more rapidly than alpha- or beta-crystallins.

Genetic and molecular studies of a composite chromosomal element (Tn3705) containing a Tn916-modified structure (Tn3704) in Streptococcus anginosus F22.

PubMed

Clermont, D; Horaud, T

1994-01-01

The plasmid-free Streptococcus anginosus F22 contained a conjugative element, Tn3705, encoding resistance to erythromycin (Emr) and tetracycline-minocycline (Tcr-Mnr). We mapped a chromosomal region (> 52 kb) of F22, corresponding to the internal part of Tn3705. Molecular analysis of Tn3705 revealed it to be a composite structure: it included in its central part a transposon designated Tn3704 (20.3 kb +/- 0.5 kb), which had a modified structure in comparison with that of Tn916 and on which the Emr Tcr-Mn4 markers were localized. Tn3705 inserted from F22 into the chromosome of various streptococcal transconjugants as well as that of Enterococcus faecalis transconjugants without changing its structure. In contrast, from the chromosome of an E. faecalis::Tn3705 transconjugant only Tn3704 inserted, at various sites, into another E. faecalis chromosome. Sugar fermentations occurred after the insertion of Tn3704 into the chromosome of an asaccharolytic E. faecalis strain. Transposition of only Tn3704 from the chromosome of E. faecalis::Tn3705 onto pIP964, an E. faecalis hemolysin plasmid, yielded two different pIP964 derivatives. The size of the entire element Tn3705 was estimated to be about 70.0 kb by pulsed-field electrophoresis.

[A METHOD FOR DIFFERENTIATION OF BACILLUS ANTHRACIS STRAINS AND PHYLOGENETICALLY RELATED SPECIES BASED ON DETERMINATION OF THE STRUCTURAL DIFFERENCESBETWEEN CHROMOSOMAL GENES FOR BIOSYNTHESIS OF FLAGELLIN AND METHIONINE].

PubMed

Mikshis, N I; Kashtanova, T N; Kutyrev, V V

2015-01-01

Nucleotide sequence analysis of several genes responsible for the anthrax pathogen definitive properties--motility and penicillinase activity--determined a chromosomal locus promising for interspecies differentiation. We demonstrated that the gene fliC encoding flagellin synthesis contains extended region, distinguishing B. anthracis strains from the majority of non-pathogenic and opportunistic bacilli. A novel method for the anthrax pathogen indication and identification based on determination of the differences in the chromosomal genes fliC and hom2 structure was suggested. A total of 60 strains of different Bacillus spp. (B. anthracis, B. cereus, B. thuringiensis, B. mycoides, B. megaterium, B. subtilis, etc.) were tested using two chromosomal DNA targets. The algorithm developed in this work permits to detect the pathogenic microorganism and reliably differentiate it from other Bacillus spp. representatives. The introduction of primers complementary to specific sequences of pXO1 and pXQ2 plasmids into the multiplex PCR makes it possible to receive additional information on proposed virulence of the isolate.

The Obligate Human Pathogen, Neisseria gonorrhoeae, Is Polyploid

PubMed Central

Tobiason, Deborah M; Seifert, H. Steven

2006-01-01

We show using several methodologies that the Gram-negative, diplococcal-bacterium Neisseria gonorrhoeae has more than one complete genome copy per cell. Gene dosage measurements demonstrated that only a single replication initiation event per chromosome occurs per round of cell division, and that there is a single origin of replication. The region containing the origin does not encode any genes previously associated with bacterial origins of replication. Quantitative PCR results showed that there are on average three genome copies per coccal cell unit. These findings allow a model for gonococcal DNA replication and cell division to be proposed, in which a minimum of two chromosomal copies exist per coccal unit within a monococcal or diplococcal cell, and these chromosomes replicate in unison to produce four chromosomal copies during cell division. Immune evasion via antigenic variation is an important mechanism that allows these organisms to continually infect a high risk population of people. We propose that polyploidy may be necessary for the high frequency gene conversion system that mediates pilin antigenic variation and the propagation of N. gonorrhoeae within its human hosts. PMID:16719561

Cloning and expression of the cDNA encoding human fumarylacetoacetate hydrolase, the enzyme deficient in hereditary tyrosinemia: assignment of the gene to chromosome 15.

PubMed Central

Phaneuf, D; Labelle, Y; Bérubé, D; Arden, K; Cavenee, W; Gagné, R; Tanguay, R M

1991-01-01

Type 1 hereditary tyrosinemia (HT) is an autosomal recessive disease characterized by a deficiency of the enzyme fumarylacetoacetate hydrolase (FAH; E.C.3.7.1.2). We have isolated human FAH cDNA clones by screening a liver cDNA expression library using specific antibodies and plaque hybridization with a rat FAH cDNA probe. A 1,477-bp cDNA was sequenced and shown to code for FAH by an in vitro transcription-translation assay and sequence homology with tryptic fragments of purified FAH. Transient expression of this FAH cDNA in transfected CV-1 mammalian cells resulted in the synthesis of an immunoreactive protein comigrating with purified human liver FAH on SDS-PAGE and having enzymatic activity as shown by the hydrolysis of the natural substrate fumarylacetoacetate. This indicates that the single polypeptide chain encoded by the FAH gene contains all the genetic information required for functional activity, suggesting that the dimer found in vivo is a homodimer. The human FAH cDNA was used as a probe to determine the gene's chromosomal localization using somatic cell hybrids and in situ hybridization. The human FAH gene maps to the long arm of chromosome 15 in the region q23-q25. Images Figure 1 Figure 3 Figure 4 Figure 6 Figure 8 PMID:1998338

Chromosomal characteristics and distribution of rDNA sequences in the brook trout Salvelinus fontinalis (Mitchill, 1814).

PubMed

Śliwińska-Jewsiewicka, A; Kuciński, M; Kirtiklis, L; Dobosz, S; Ocalewicz, K; Jankun, Malgorzata

2015-08-01

Brook trout Salvelinus fontinalis (Mitchill, 1814) chromosomes have been analyzed using conventional and molecular cytogenetic techniques enabling characteristics and chromosomal location of heterochromatin, nucleolus organizer regions (NORs), ribosomal RNA-encoding genes and telomeric DNA sequences. The C-banding and chromosome digestion with the restriction endonucleases demonstrated distribution and heterogeneity of the heterochromatin in the brook trout genome. DNA sequences of the ribosomal RNA genes, namely the nucleolus-forming 28S (major) and non-nucleolus-forming 5S (minor) rDNAs, were physically mapped using fluorescence in situ hybridization (FISH) and primed in situ labelling. The minor rDNA locus was located on the subtelo-acrocentric chromosome pair No. 9, whereas the major rDNA loci were dispersed on 14 chromosome pairs, showing a considerable inter-individual variation in the number and location. The major and minor rDNA loci were located at different chromosomes. Multichromosomal location (3-6 sites) of the NORs was demonstrated by silver nitrate (AgNO3) impregnation. All Ag-positive i.e. active NORs corresponded to the GC-rich blocks of heterochromatin. FISH with telomeric probe showed the presence of the interstitial telomeric site (ITS) adjacent to the NOR/28S rDNA site on the chromosome 11. This ITS was presumably remnant of the chromosome rearrangement(s) leading to the genomic redistribution of the rDNA sequences. Comparative analysis of the cytogenetic data among several related salmonid species confirmed huge variation in the number and the chromosomal location of rRNA gene clusters in the Salvelinus genome.

Activation of the Lbc Rho Exchange Factor Proto-Oncogene by Truncation of an Extended C Terminus That Regulates Transformation and Targeting

PubMed Central

Sterpetti, Paola; Hack, Andrew A.; Bashar, Mariam P.; Park, Brian; Cheng, Sou-De; Knoll, Joan H. M.; Urano, Takeshi; Feig, Larry A.; Toksoz, Deniz

1999-01-01

The human lbc oncogene product is a guanine nucleotide exchange factor that specifically activates the Rho small GTP binding protein, thus resulting in biologically active, GTP-bound Rho, which in turn mediates actin cytoskeletal reorganization, gene transcription, and entry into the mitotic S phase. In order to elucidate the mechanism of onco-Lbc transformation, here we report that while proto- and onco-lbc cDNAs encode identical N-terminal dbl oncogene homology (DH) and pleckstrin homology (PH) domains, proto-Lbc encodes a novel C terminus absent in the oncoprotein that includes a predicted α-helical region homologous to cyto-matrix proteins, followed by a proline-rich region. The lbc proto-oncogene maps to chromosome 15, and onco-lbc represents a fusion of the lbc proto-oncogene N terminus with a short, unrelated C-terminal sequence from chromosome 7. Both onco- and proto-Lbc can promote formation of GTP-bound Rho in vivo. Proto-Lbc transforming activity is much reduced compared to that of onco-Lbc, and a significant increase in transforming activity requires truncation of both the α-helical and proline-rich regions in the proto-Lbc C terminus. Deletion of the chromosome 7-derived C terminus of onco-Lbc does not destroy transforming activity, demonstrating that it is loss of the proto-Lbc C terminus, rather than gain of an unrelated C-terminus by onco-Lbc, that confers transforming activity. Mutations of onco-Lbc DH and PH domains demonstrate that both domains are necessary for full transforming activity. The proto-Lbc product localizes to the particulate (membrane) fraction, while the majority of the onco-Lbc product is cytosolic, and mutations of the PH domain do not affect this localization. The proto-Lbc C-terminus alone localizes predominantly to the particulate fraction, indicating that the C terminus may play a major role in the correct subcellular localization of proto-Lbc, thus providing a mechanism for regulating Lbc oncogenic potential. PMID:9891067

The 2p21 deletion syndrome: characterization of the transcription content.

PubMed

Parvari, Ruti; Gonen, Yael; Alshafee, Ismael; Buriakovsky, Sophia; Regev, Kfir; Hershkovitz, Eli

2005-08-01

The vast majority of small-deletion syndromes are caused by haploinsufficiency of one or several genes and are transmitted as dominant traits. We have previously identified a homozygous deletion of 179,311 bp on chromosome 2p21 as the cause of a unique syndrome, inherited in a recessive mode, consisting of cystinuria, neonatal seizures, hypotonia, severe somatic and developmental delay, facial dysmorphism, and reduced activity of all the respiratory chain enzymatic complexes that are encoded in the mitochondria. We now present the transcription content of this region: Multiple splicing variants of the genes protein phosphatase 1B (formerly 2C) magnesium-dependent, beta isoform (PPM1B), SLC3A1, and KIAA0436 (approved gene symbol PREPL) were identified and their patterns of expression analyzed. The spliced variants are predicted to have additional functions compared to the known variants and their patterns of expression fit the tissues affected by the syndrome. The first exon of an additional gene (C2orf34) is encoded in the deleted region and the gene is not expressed in the patients. In addition several transcripts with very short open reading frames are also encoded in the deletion. The identification of all transcripts encoded in the region deleted in the patients is the first step in the study of the genotype-phenotype correlation of the 2p21 patients.

Molecular mapping of 21 features associated with partial monosomy 21: Involvement of the APP-SODI region

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

Chettouh, Z.; Maunoury, C.; Sinet, P.M.

1995-07-01

We compared the phenotypes, karyotypes, and molecular data for six cases of partial monosomy 21. Regions of chromosome 21, the deletion of which corresponds to particular features of monosomy 21, were thereby defined. Five such regions were identified for 21 features. Ten of the features could be assigned to the region flanked by genes APP and SOD1: six facial features, transverse palmar crease, arthrogryposis-like symptoms, hypertonia, and contribution to mental retardation. This region, covering the interface of bands 21q21-21q22.1, is 4.7-6.4 Mb long and contains the gene encoding the glutamate receptor subunit GluR5 (GRIK1). 82 refs., 5 figs., 1 tab.

Recognition of A. thaliana centromeres by heterologous CENH3 requires high similarity to the endogenous protein.

PubMed

Moraes, Izabel C R; Lermontova, Inna; Schubert, Ingo

2011-02-01

The centromere is an essential chromosomal component assembling the kinetochore for chromosome attachment to the spindle microtubules and for directing the chromosome segregation during nuclear division. Kinetochore assembly requires deposition of the centromeric histone H3 variant (CENH3) into centromeric nucleosomes. CENH3 has a variable N-terminal and a more conserved C-terminal part, including the loop1 region of the histone fold domain, which is considered to be critical for centromere targeting. To investigate the structural requirements for centromere targeting, constructs for EYFP-tagged CENH3 of A. lyrata, A. arenosa, Capsella bursa-pastoris, Zea mays and Luzula nivea (the latter with holocentric chromosomes) were transformed into A. thaliana. Except for LnCENH3, all recombinant CENH3 proteins targeted A. thaliana centromeres, but the more distantly related the heterologous protein is, the lower is the efficiency of targeting. Alignment of CENH3 sequences revealed that the tested species share only three amino acids at loop1 region: threonine2, arginine12 and alanine15. These three amino acids were substituted by asparagine, proline and valine encoding sequences within a recombinant EYFP-AtCENH3 construct via PCR mutagenesis prior to transformation of A. thaliana. After transformation, immunostaining of root tip nuclei with anti-GFP antibodies yielded only diffuse signals, indicating that the original three amino acids are necessary but not sufficient for targeting A. thaliana centromeres.

Molecular cloning and chromosomal localization of a pseudogene related to the human Acyl-CoA binding protein/diazepam binding inhibitor

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

Gersuk, V.H.; Rose, T.M.; Todaro, G.J.

The acyl-CoA binding protein (ACBP) and the diazepam binding inhibitor (DBI) or endozepine are independent isolates of a single 86-amino-acid, 10-kDa protein. ACBP/DBI is highly conserved between species and has been identified in several diverse organisms, including human, cow, rat, frog, duck, insects, plants, and yeast. Although the genomic locus has not yet been cloned in humans, complementary DNA clones with different 5{prime} ends have been isolated and characterized. These cDNA clones appear to be encoded by a single gene. However, Southern blot analyses, in situ hybridizations, and somatic cell hybrid chromosomal mapping all suggest that there are multiple ACBP/DBI-relatedmore » sequences in the genome. To identify potential members of this gene family, degenerate oligonucleotides corresponding to highly conserved regions of ACBP/DBI were used to screen a human genomic DNA library using the polymerase chain reaction. A novel gene, DBIP1, that is closely related to ACBP/DBI but is clearly distinct was identified. DBIP1 bears extensive sequence homology to ACBP/DBI but lacks the introns predicted by rat and duck genomic sequence studies. A 1-base deletion in the coding region results in a frameshift and, along with the absence of introns and the lack of a detectable transcript, suggests that DBIP1 is a pseudogene. ACBP/DBI has previously been mapped to chromosome 2, although this was recently disputed, and a chromosome 6 location was suggested. We show that ACBP/DBI is correctly placed on chromosome 2 and that the gene identified on chromosome 6 is DBIP1. 33 refs., 3 figs., 1 tab.« less

Genome-wide association analyses of child genotype effects and parent-of-origin effects in specific language impairment

PubMed Central

Nudel, R; Simpson, N H; Baird, G; O’Hare, A; Conti-Ramsden, G; Bolton, P F; Hennessy, E R; Ring, S M; Davey Smith, G; Francks, C; Paracchini, S; Monaco, A P; Fisher, S E; Newbury, D F

2014-01-01

Specific language impairment (SLI) is a neurodevelopmental disorder that affects linguistic abilities when development is otherwise normal. We report the results of a genome-wide association study of SLI which included parent-of-origin effects and child genotype effects and used 278 families of language-impaired children. The child genotype effects analysis did not identify significant associations. We found genome-wide significant paternal parent-of-origin effects on chromosome 14q12 (P = 3.74 × 10−8) and suggestive maternal parent-of-origin effects on chromosome 5p13 (P = 1.16 × 10−7). A subsequent targeted association of six single-nucleotide-polymorphisms (SNPs) on chromosome 5 in 313 language-impaired individuals and their mothers from the ALSPAC cohort replicated the maternal effects, albeit in the opposite direction (P = 0.001); as fathers’ genotypes were not available in the ALSPAC study, the replication analysis did not include paternal parent-of-origin effects. The paternally-associated SNP on chromosome 14 yields a non-synonymous coding change within the NOP9 gene. This gene encodes an RNA-binding protein that has been reported to be significantly dysregulated in individuals with schizophrenia. The region of maternal association on chromosome 5 falls between the PTGER4 and DAB2 genes, in a region previously implicated in autism and ADHD. The top SNP in this association locus is a potential expression QTL of ARHGEF19 (also called WGEF) on chromosome 1. Members of this protein family have been implicated in intellectual disability. In summary, this study implicates parent-of-origin effects in language impairment, and adds an interesting new dimension to the emerging picture of shared genetic etiology across various neurodevelopmental disorders. PMID:24571439

IQCJ-SCHIP1, a novel fusion transcript encoding a calmodulin-binding IQ motif protein

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

Kwasnicka-Crawford, Dorota A.; Carson, Andrew R.; Scherer, Stephen W.

The existence of transcripts that span two adjacent, independent genes is considered rare in the human genome. This study characterizes a novel human fusion gene named IQCJ-SCHIP1. IQCJ-SCHIP1 is the longest isoform of a complex transcriptional unit that bridges two separate genes that encode distinct proteins, IQCJ, a novel IQ motif containing protein and SCHIP1, a schwannomin interacting protein that has been previously shown to interact with the Neurofibromatosis type 2 (NF2) protein. IQCJ-SCHIP1 is located on the chromosome 3q25 and comprises a 1692-bp transcript encompassing 11 exons spanning 828 kb of the genomic DNA. We show that IQCJ-SCHIP1 mRNAmore » is highly expressed in the brain. Protein encoded by the IQCJ-SCHIP1 gene was localized to cytoplasm and actin-rich regions and in differentiated PC12 cells was also seen in neurite extensions.« less

Cloning of the canine gene encoding transcription factor Pit-1 and its exclusion as candidate gene in a canine model of pituitary dwarfism.

PubMed

Lantinga-van Leeuwen, I S; Mol, J A; Kooistra, H S; Rijnberk, A; Breen, M; Renier, C; van Oost, B A

2000-01-01

Combined pituitary hormone deficiency (CPHD) is an autosomal recessive inherited disease of German shepherd dogs characterized primarily by dwarfism. In mice and humans a similar genetic disorder has been described that results from an alteration in the gene encoding the transcription factor Pit-1. In this study we characterized the canine Pit-1 gene, determined the chromosomal localization of the Pit-1 gene, and screened dwarf German shepherd dogs for the presence of mutations in this gene. The full-length canine Pit-1 cDNA contained an open reading frame encoding 291 amino acids, 92 bp of 5'-untranslated region, and 1959 bp of 3'-untranslated region. The deduced amino acid sequence was highly homologous with Pit-1 of other mammalian species. Using a Pit-1 BAC clone as probe, the Pit-1 gene was mapped by FISH to canine Chromosome (Chr) 31. In dwarf German shepherd dogs a C to A transversion was detected, causing a Phe (TTC) to Leu (TTA) substitution at codon 81. This alteration was present neither in other canine breeds analyzed nor in other mammalian species. However, healthy German shepherd dogs were also homozygous for the mutant allele, indicating that it is not the primary disease-causing mutation. In addition, linkage analysis of polymorphic DNA markers flanking the Pit-1 gene, 41K19 and 52L05, revealed no co-segregation between the Pit-1 locus and the CPHD phenotype. These findings suggest that a gene other than Pit-1 is responsible for the pituitary anomaly in dwarf German shepherd dogs.

Analysis of the regulatory region of the protease III (ptr) gene of Escherichia coli K-12.

PubMed

Claverie-Martin, F; Diaz-Torres, M R; Kushner, S R

1987-01-01

The ptr gene of Escherichia coli encodes protease III (Mr 110,000) and a 50-kDa polypeptide, both of which are found in the periplasmic space. The gene is physically located between the recC and recB loci on the E. coli chromosome. The nucleotide sequence of a 1167-bp EcoRV-ClaI fragment of chromosomal DNA containing the promoter region and 885 bp of the ptr coding sequence has been determined. S1 nuclease mapping analysis showed that the major 5' end of the ptr mRNA was localized 127 bp upstream from the ATG start codon. The open reading frame (ORF), preceded by a Shine-Dalgarno sequence, extends to the end of the sequenced DNA. Downstream from the -35 and -10 regions is a sequence that strongly fits the consensus sequence of known nitrogen-regulated promoters. A signal peptide of 23 amino acids residues is present at the N terminus of the derived amino acid sequence. The cleavage site as well as the ORF were confirmed by sequencing the N terminus of mature protease III.

Identification of Atg2 and ArfGAP1 as Candidate Genetic Modifiers of the Eye Pigmentation Phenotype of Adaptor Protein-3 (AP-3) Mutants in Drosophila melanogaster.

PubMed

Rodriguez-Fernandez, Imilce A; Dell'Angelica, Esteban C

2015-01-01

The Adaptor Protein (AP)-3 complex is an evolutionary conserved, molecular sorting device that mediates the intracellular trafficking of proteins to lysosomes and related organelles. Genetic defects in AP-3 subunits lead to impaired biogenesis of lysosome-related organelles (LROs) such as mammalian melanosomes and insect eye pigment granules. In this work, we have performed a forward screening for genetic modifiers of AP-3 function in the fruit fly, Drosophila melanogaster. Specifically, we have tested collections of large multi-gene deletions--which together covered most of the autosomal chromosomes-to identify chromosomal regions that, when deleted in single copy, enhanced or ameliorated the eye pigmentation phenotype of two independent AP-3 subunit mutants. Fine-mapping led us to define two non-overlapping, relatively small critical regions within fly chromosome 3. The first critical region included the Atg2 gene, which encodes a conserved protein involved in autophagy. Loss of one functional copy of Atg2 ameliorated the pigmentation defects of mutants in AP-3 subunits as well as in two other genes previously implicated in LRO biogenesis, namely Blos1 and lightoid, and even increased the eye pigment content of wild-type flies. The second critical region included the ArfGAP1 gene, which encodes a conserved GTPase-activating protein with specificity towards GTPases of the Arf family. Loss of a single functional copy of the ArfGAP1 gene ameliorated the pigmentation phenotype of AP-3 mutants but did not to modify the eye pigmentation of wild-type flies or mutants in Blos1 or lightoid. Strikingly, loss of the second functional copy of the gene did not modify the phenotype of AP-3 mutants any further but elicited early lethality in males and abnormal eye morphology when combined with mutations in Blos1 and lightoid, respectively. These results provide genetic evidence for new functional links connecting the machinery for biogenesis of LROs with molecules implicated in autophagy and small GTPase regulation.

The Streptococcus pyogenes serotype M49 Nra-Ralp3 transcriptional regulatory network and its control of virulence factor expression from the novel eno ralp3 epf sagA pathogenicity region.

PubMed

Kreikemeyer, Bernd; Nakata, Masanobu; Köller, Thomas; Hildisch, Hendrikje; Kourakos, Vassilios; Standar, Kerstin; Kawabata, Shigetada; Glocker, Michael O; Podbielski, Andreas

2007-12-01

Many Streptococcus pyogenes (group A streptococcus [GAS]) virulence factor- and transcriptional regulator-encoding genes cluster together in discrete genomic regions. Nra is a central regulator of the FCT region. Previous studies exclusively described Nra as a transcriptional repressor of adhesin and toxin genes. Here transcriptome and proteome analysis of a serotype M49 GAS strain and an isogenic Nra mutant of this strain revealed the complete Nra regulon profile. Nra is active in all growth phases tested, with the largest regulon in the transition phase. Almost exclusively, virulence factor-encoding genes are repressed by Nra; these genes include the GAS pilus operon, the capsule synthesis operon, the cytolysin-mediated translocation system genes, all Mga region core virulence genes, and genes encoding other regulators, like the Ihk/Irr system, Rgg, and two additional RofA-like protein family regulators. Surprisingly, our experiments revealed that Nra additionally acts as a positive regulator, mostly for genes encoding proteins and enzymes with metabolic functions. Epidemiological investigations revealed strong genetic linkage of one particular Nra-repressed regulator, Ralp3 (SPy0735), with a gene encoding Epf (extracellular protein factor from Streptococcus suis). In a serotype-specific fashion, this ralp3 epf gene block is integrated, most likely via transposition, into the eno sagA virulence gene block, which is present in all GAS serotypes. In GAS serotypes M1, M4, M12, M28, and M49 this novel discrete genetic region is therefore designated the eno ralp3 epf sagA (ERES) pathogenicity region. Functional experiments showed that Epf is a novel GAS plasminogen-binding protein and revealed that Ralp3 activity counteracts Nra and MsmR regulatory activity. In addition to the Mga and FCT regions, the ERES region is the third discrete chromosomal pathogenicity region. All of these regions are transcriptionally linked, adding another level of complexity to the known GAS growth phase-dependent regulatory network.

Cloning and genomic characterization of sytdep, a new synaptotagmin XIV-related gene.

PubMed

Herrero-Turrión, M Javier; Fukuda, Mitsunori; Mollinedo, Faustino

2006-02-10

We have identified a new human gene coined sytdep (synaptotagmin XIV-derived protein) in human neutrophils. Sytdep encodes a 188-amino acid sequence with a 21.435kDa deduced molecular mass, showing 75% identity to human synaptotagmin (syt) XIV. Human neutrophils express sytdep, but not syt XIV. Sytdep was upregulated during HL-60 neutrophil differentiation. Sytdep gene is located in human chromosome 4 and contains a unique exon, whereas syt XIV gene, located in chromosome 1, comprises 10 exons with 9 introns. Mouse genome did not contain sytdep. The N-terminal region of sytdep shows no homology with any known protein and, unlike synaptotagmin XIV isoforms, sytdep shows a unique C-terminal C2B domain. Polyclonal antibodies against the C2B domain of syt XIV recognized sytdep as a 27-kDa protein in human neutrophils. Genomic analyses suggest that human sytdep could derive from a retrotranslocation of a syt XIV transcript into chromosome 4.

Positional cloning of disease genes on chromosome 16

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

Doggett, N.; Bruening, M.; Callen, D.

1996-04-01

The project seeks to elucidate the molecular basis of an important genetic disease (Batten`s disease) by molecular cloning of the affected gene by utilizing an overlapping clone map of chromosome 16. Batten disease (also known as juvenile neuronal ceroid lipofuscinosis) is a recessively inherited neurodegenerative disorder of childhood characterized by progressive loss of vision, seizures, and psychomoter disturbances. The Batten disease gene was genetically mapped to the chromosome region 16p 12.1 in close linkage with the genetic markers D16S299 and D16S298. Exon amplification of a cosmid containing D16S298 yielded a candidate gene that was disrupted by a 1 kb genomicmore » deletion in all patients containing the most common haplotype for the disease. Two separate deletions and a point mutation altering a splice site in three unrelated families have confirmed the gene as the Batten disease gene. The disease gene encodes a novel 438 amino acid membrane binding protein of unknown function.« less

Identification of Drivers of Aneuploidy in Breast Tumors.

PubMed

Pfister, Katherine; Pipka, Justyna L; Chiang, Colby; Liu, Yunxian; Clark, Royden A; Keller, Ray; Skoglund, Paul; Guertin, Michael J; Hall, Ira M; Stukenberg, P Todd

2018-05-29

Although aneuploidy is found in the majority of tumors, the degree of aneuploidy varies widely. It is unclear how cancer cells become aneuploid or how highly aneuploid tumors are different from those of more normal ploidy. We developed a simple computational method that measures the degree of aneuploidy or structural rearrangements of large chromosome regions of 522 human breast tumors from The Cancer Genome Atlas (TCGA). Highly aneuploid tumors overexpress activators of mitotic transcription and the genes encoding proteins that segregate chromosomes. Overexpression of three mitotic transcriptional regulators, E2F1, MYBL2, and FOXM1, is sufficient to increase the rate of lagging anaphase chromosomes in a non-transformed vertebrate tissue, demonstrating that this event can initiate aneuploidy. Highly aneuploid human breast tumors are also enriched in TP53 mutations. TP53 mutations co-associate with the overexpression of mitotic transcriptional activators, suggesting that these events work together to provide fitness to breast tumors. Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.

The Drosophila melanogaster Homologue of the Xeroderma Pigmentosum D Gene Product Is Located in Euchromatic Regions and Has a Dynamic Response to UV Light-induced Lesions in Polytene Chromosomes

PubMed Central

Reynaud, Enrique; Lomelí, Hilda; Vázquez, Martha; Zurita, Mario

1999-01-01

The XPD/ERCC2/Rad3 gene is required for excision repair of UV-damaged DNA and is an important component of nucleotide excision repair. Mutations in the XPD gene generate the cancer-prone syndrome, xeroderma pigmentosum, Cockayne’s syndrome, and trichothiodystrophy. XPD has a 5′- to 3′-helicase activity and is a component of the TFIIH transcription factor, which is essential for RNA polymerase II elongation. We present here the characterization of the Drosophila melanogaster XPD gene (DmXPD). DmXPD encodes a product that is highly related to its human homologue. The DmXPD protein is ubiquitous during development. In embryos at the syncytial blastoderm stage, DmXPD is cytoplasmic. At the onset of transcription in somatic cells and during gastrulation in germ cells, DmXPD moves to the nuclei. Distribution analysis in polytene chromosomes shows that DmXPD is highly concentrated in the interbands, especially in the highly transcribed regions known as puffs. UV-light irradiation of third-instar larvae induces an increase in the signal intensity and in the number of sites where the DmXPD protein is located in polytene chromosomes, indicating that the DmXPD protein is recruited intensively in the chromosomes as a response to DNA damage. This is the first time that the response to DNA damage by UV-light irradiation can be visualized directly on the chromosomes using one of the TFIIH components. PMID:10198066

Distinct prophase arrest mechanisms in human male meiosis.

PubMed

Jan, Sabrina Z; Jongejan, Aldo; Korver, Cindy M; van Daalen, Saskia K M; van Pelt, Ans M M; Repping, Sjoerd; Hamer, Geert

2018-04-16

To prevent chromosomal aberrations being transmitted to the offspring, strict meiotic checkpoints are in place to remove aberrant spermatocytes. However, in about 1% of males these checkpoints cause complete meiotic arrest leading to azoospermia and subsequent infertility. Here, we unravel two clearly distinct meiotic arrest mechanisms that occur during prophase of human male meiosis. Type I arrested spermatocytes display severe asynapsis of the homologous chromosomes, disturbed XY-body formation and increased expression of the Y chromosome-encoded gene ZFY and seem to activate a DNA damage pathway leading to induction of p63, possibly causing spermatocyte apoptosis. Type II arrested spermatocytes display normal chromosome synapsis, normal XY-body morphology and meiotic crossover formation but have a lowered expression of several cell cycle regulating genes and fail to silence the X chromosome-encoded gene ZFX Discovery and understanding of these meiotic arrest mechanisms increases our knowledge of how genomic stability is guarded during human germ cell development. © 2018. Published by The Company of Biologists Ltd.

The mammalian homologue of mago nashi encodes a serum-inducible protein.

PubMed

Zhao, X F; Colaizzo-Anas, T; Nowak, N J; Shows, T B; Elliott, R W; Aplan, P D

1998-01-15

The products of at least 11 maternal effect genes have been shown to be essential for proper germ plasm assembly in Drosophila melanogaster embryos. Here we report the isolation and characterization of the mammalian counterpart for one of these genes (named MAGOH for mago nashi homologue). The predicted amino acid sequence of mouse and human MAGOH are completely identical; MAGOH homologues from the nematode Caenorhabditis elegans and rice grain Oryza sativa also show a remarkable degree of amino acid conservation. MAGOH was mapped to chromosome 1p33-p34 in the human and a syntenic region of chromosome 4 in the mouse. Of note, MAGOH mRNA expression is not limited to germ plasm, but is expressed ubiquitously in adult tissues and can be induced by serum stimulation of quiescent fibroblasts.

Distinct chromatin environment associated with phosphorylated H3S10 histone during pollen mitosis I in orchids.

PubMed

Sharma, Santosh Kumar; Yamamoto, Maki; Mukai, Yasuhiko

2017-01-01

Pollen developmental pathway in plants involving synchronized transferal of cellular divisions from meiosis (microsporogenesis) to mitosis (pollen mitosis I/II) eventually offers a unique "meiosis-mitosis shift" at pollen mitosis I. Since the cell type (haploid microspore) and fate of pollen mitosis I differ from typical mitosis (in meristem cells), it is immensely important to analyze the chromosomal distribution of phosphorylated H3S10 histone during atypical pollen mitosis I to comprehend the role of histone phosphorylation in pollen development. We investigated the chromosomal phosphorylation of H3S10 histone during pollen mitosis I in orchids using immunostaining technique. The chromosomal distribution of H3S10ph during pollen mitosis I revealed differential pattern than that of typical mitosis in plants, however, eventually following the similar trends of mitosis in animals where H3S10 phosphorylation begins in the pericentromeric regions first, later extending to the whole chromosomes, and finally declining at anaphase/early cytokinesis (differentiation of vegetative and generative cells). The study suggests that the chromosomal distribution of H3S10ph during cell division is not universal and can be altered between different cell types encoded for diverse cellular processes. During pollen development, phosphorylation of histone might play a critical role in chromosome condensation events throughout pollen mitosis I in plants.

The Streptococcus pyogenes Serotype M49 Nra-Ralp3 Transcriptional Regulatory Network and Its Control of Virulence Factor Expression from the Novel eno ralp3 epf sagA Pathogenicity Region▿ †

PubMed Central

Kreikemeyer, Bernd; Nakata, Masanobu; Köller, Thomas; Hildisch, Hendrikje; Kourakos, Vassilios; Standar, Kerstin; Kawabata, Shigetada; Glocker, Michael O.; Podbielski, Andreas

2007-01-01

Many Streptococcus pyogenes (group A streptococcus [GAS]) virulence factor- and transcriptional regulator-encoding genes cluster together in discrete genomic regions. Nra is a central regulator of the FCT region. Previous studies exclusively described Nra as a transcriptional repressor of adhesin and toxin genes. Here transcriptome and proteome analysis of a serotype M49 GAS strain and an isogenic Nra mutant of this strain revealed the complete Nra regulon profile. Nra is active in all growth phases tested, with the largest regulon in the transition phase. Almost exclusively, virulence factor-encoding genes are repressed by Nra; these genes include the GAS pilus operon, the capsule synthesis operon, the cytolysin-mediated translocation system genes, all Mga region core virulence genes, and genes encoding other regulators, like the Ihk/Irr system, Rgg, and two additional RofA-like protein family regulators. Surprisingly, our experiments revealed that Nra additionally acts as a positive regulator, mostly for genes encoding proteins and enzymes with metabolic functions. Epidemiological investigations revealed strong genetic linkage of one particular Nra-repressed regulator, Ralp3 (SPy0735), with a gene encoding Epf (extracellular protein factor from Streptococcus suis). In a serotype-specific fashion, this ralp3 epf gene block is integrated, most likely via transposition, into the eno sagA virulence gene block, which is present in all GAS serotypes. In GAS serotypes M1, M4, M12, M28, and M49 this novel discrete genetic region is therefore designated the eno ralp3 epf sagA (ERES) pathogenicity region. Functional experiments showed that Epf is a novel GAS plasminogen-binding protein and revealed that Ralp3 activity counteracts Nra and MsmR regulatory activity. In addition to the Mga and FCT regions, the ERES region is the third discrete chromosomal pathogenicity region. All of these regions are transcriptionally linked, adding another level of complexity to the known GAS growth phase-dependent regulatory network. PMID:17893125

Identification of a fourth locus (EVR4) for familial exudative vitreoretinopathy (FEVR).

PubMed

Toomes, Carmel; Downey, Louise M; Bottomley, Helen M; Scott, Sheila; Woodruff, Geoffrey; Trembath, Richard C; Inglehearn, Chris F

2004-01-15

Familial exudative vitreoretinopathy (FEVR) is a genetically heterogeneous inherited blinding disorder of the retinal vascular system. To date three loci have been mapped: EVR1 on chromosome 11q, EVR2 on chromosome Xp, and EVR3 on chromosome 11p. The gene underlying EVR3 remains unidentified whilst the EVR2 gene, which encodes the Norrie disease protein (NDP), was identified over a decade ago. More recently, FZD4, the gene that encodes the Wnt receptor Frizzled-4, was identified as the mutated gene at the EVR1 locus. The purpose of this study was to screen FZD4 in a large family previously proven to be linked to the EVR1 locus. PCR products were generated using genomic DNA from affected family members with primers designed to amplify the coding sequence of FZD4. The PCR products were screened for mutations by direct sequencing. Genotyping was performed in all available family members using fluorescently labeled microsatellite markers from chromosome 11q. Sequencing of the EVR1 gene, FZD4, in this family identified no mutation. To investigate this family further we performed high-resolution genotyping with markers spanning chromosome 11q. Haplotype analysis excluded FZD4 as the mutated gene in this family and identified a candidate region approximately 10 cM centromeric to EVR1. This new FEVR locus is flanked by markers D11S1368 (centromeric) and D11S937 (telomeric) and spans approximately 15 cM. High-resolution genotyping and haplotype analysis excluded FZD4 as the defective gene in a family previously linked to the EVR1 locus. The results indicate that the gene mutated in this family lies centromeric to the EVR1 gene, FZD4, and is also genetically distinct from the EVR3 locus. This new locus has been designated EVR4 and is the fourth FEVR locus to be described.

De novo prediction of human chromosome structures: Epigenetic marking patterns encode genome architecture.

PubMed

Di Pierro, Michele; Cheng, Ryan R; Lieberman Aiden, Erez; Wolynes, Peter G; Onuchic, José N

2017-11-14

Inside the cell nucleus, genomes fold into organized structures that are characteristic of cell type. Here, we show that this chromatin architecture can be predicted de novo using epigenetic data derived from chromatin immunoprecipitation-sequencing (ChIP-Seq). We exploit the idea that chromosomes encode a 1D sequence of chromatin structural types. Interactions between these chromatin types determine the 3D structural ensemble of chromosomes through a process similar to phase separation. First, a neural network is used to infer the relation between the epigenetic marks present at a locus, as assayed by ChIP-Seq, and the genomic compartment in which those loci reside, as measured by DNA-DNA proximity ligation (Hi-C). Next, types inferred from this neural network are used as an input to an energy landscape model for chromatin organization [Minimal Chromatin Model (MiChroM)] to generate an ensemble of 3D chromosome conformations at a resolution of 50 kilobases (kb). After training the model, dubbed Maximum Entropy Genomic Annotation from Biomarkers Associated to Structural Ensembles (MEGABASE), on odd-numbered chromosomes, we predict the sequences of chromatin types and the subsequent 3D conformational ensembles for the even chromosomes. We validate these structural ensembles by using ChIP-Seq tracks alone to predict Hi-C maps, as well as distances measured using 3D fluorescence in situ hybridization (FISH) experiments. Both sets of experiments support the hypothesis of phase separation being the driving process behind compartmentalization. These findings strongly suggest that epigenetic marking patterns encode sufficient information to determine the global architecture of chromosomes and that de novo structure prediction for whole genomes may be increasingly possible. Copyright © 2017 the Author(s). Published by PNAS.

Mouse Y-linked Zfy1 and Zfy2 are expressed during the male-specific interphase between meiosis I and meiosis II and promote the 2nd meiotic division.

PubMed

Vernet, Nadège; Mahadevaiah, Shantha K; Yamauchi, Yasuhiro; Decarpentrie, Fanny; Mitchell, Michael J; Ward, Monika A; Burgoyne, Paul S

2014-06-01

Mouse Zfy1 and Zfy2 encode zinc finger transcription factors that map to the short arm of the Y chromosome (Yp). They have previously been shown to promote meiotic quality control during pachytene (Zfy1 and Zfy2) and at the first meiotic metaphase (Zfy2). However, from these previous studies additional roles for genes encoded on Yp during meiotic progression were inferred. In order to identify these genes and investigate their function in later stages of meiosis, we created three models with diminishing Yp and Zfy gene complements (but lacking the Y-long-arm). Since the Y-long-arm mediates pairing and exchange with the X via their pseudoautosomal regions (PARs) we added a minute PAR-bearing X chromosome derivative to enable formation of a sex bivalent, thus avoiding Zfy2-mediated meiotic metaphase I (MI) checkpoint responses to the unpaired (univalent) X chromosome. Using these models we obtained definitive evidence that genetic information on Yp promotes meiosis II, and by transgene addition identified Zfy1 and Zfy2 as the genes responsible. Zfy2 was substantially more effective and proved to have a much more potent transactivation domain than Zfy1. We previously established that only Zfy2 is required for the robust apoptotic elimination of MI spermatocytes in response to a univalent X; the finding that both genes potentiate meiosis II led us to ask whether there was de novo Zfy1 and Zfy2 transcription in the interphase between meiosis I and meiosis II, and this proved to be the case. X-encoded Zfx was also expressed at this stage and Zfx over-expression also potentiated meiosis II. An interphase between the meiotic divisions is male-specific and we previously hypothesised that this allows meiosis II critical X and Y gene reactivation following sex chromosome silencing in meiotic prophase. The interphase transcription and meiosis II function of Zfx, Zfy1 and Zfy2 validate this hypothesis.

Mouse Y-Linked Zfy1 and Zfy2 Are Expressed during the Male-Specific Interphase between Meiosis I and Meiosis II and Promote the 2nd Meiotic Division

PubMed Central

Vernet, Nadège; Mahadevaiah, Shantha K.; Yamauchi, Yasuhiro; Decarpentrie, Fanny; Mitchell, Michael J.; Ward, Monika A.; Burgoyne, Paul S.

2014-01-01

Mouse Zfy1 and Zfy2 encode zinc finger transcription factors that map to the short arm of the Y chromosome (Yp). They have previously been shown to promote meiotic quality control during pachytene (Zfy1 and Zfy2) and at the first meiotic metaphase (Zfy2). However, from these previous studies additional roles for genes encoded on Yp during meiotic progression were inferred. In order to identify these genes and investigate their function in later stages of meiosis, we created three models with diminishing Yp and Zfy gene complements (but lacking the Y-long-arm). Since the Y-long-arm mediates pairing and exchange with the X via their pseudoautosomal regions (PARs) we added a minute PAR-bearing X chromosome derivative to enable formation of a sex bivalent, thus avoiding Zfy2-mediated meiotic metaphase I (MI) checkpoint responses to the unpaired (univalent) X chromosome. Using these models we obtained definitive evidence that genetic information on Yp promotes meiosis II, and by transgene addition identified Zfy1 and Zfy2 as the genes responsible. Zfy2 was substantially more effective and proved to have a much more potent transactivation domain than Zfy1. We previously established that only Zfy2 is required for the robust apoptotic elimination of MI spermatocytes in response to a univalent X; the finding that both genes potentiate meiosis II led us to ask whether there was de novo Zfy1 and Zfy2 transcription in the interphase between meiosis I and meiosis II, and this proved to be the case. X-encoded Zfx was also expressed at this stage and Zfx over-expression also potentiated meiosis II. An interphase between the meiotic divisions is male-specific and we previously hypothesised that this allows meiosis II critical X and Y gene reactivation following sex chromosome silencing in meiotic prophase. The interphase transcription and meiosis II function of Zfx, Zfy1 and Zfy2 validate this hypothesis. PMID:24967676

The restriction-modification genes of Escherichia coli K-12 may not be selfish: they do not resist loss and are readily replaced by alleles conferring different specificities.

PubMed

O'Neill, M; Chen, A; Murray, N E

1997-12-23

Type II restriction and modification (R-M) genes have been described as selfish because they have been shown to impose selection for the maintenance of the plasmid that encodes them. In our experiments, the type I R-M system EcoKI does not behave in the same way. The genes specifying EcoKI are, however, normally residents of the chromosome and therefore our analyses were extended to monitor the deletion of chromosomal genes rather than loss of plasmid vector. If EcoKI were to behave in the same way as the plasmid-encoded type II R-M systems, the loss of the relevant chromosomal genes by mutation or recombination should lead to cell death because the cell would become deficient in modification enzyme and the bacterial chromosome would be vulnerable to the restriction endonuclease. Our data contradict this prediction; they reveal that functional type I R-M genes in the chromosome are readily replaced by mutant alleles and by alleles encoding a type I R-M system of different specificity. The acquisition of allelic genes conferring a new sequence specificity, but not the loss of the resident genes, is dependent on the product of an unlinked gene, one predicted [Prakash-Cheng, A., Chung, S. S. & Ryu, J. (1993) Mol. Gen. Genet. 241, 491-496] to be relevant to control of expression of the genes that encode EcoKI. Our evidence suggests that not all R-M systems are evolving as "selfish" units; rather, the diversity and distribution of the family of type I enzymes we have investigated require an alternative selective pressure.

Genetic analysis of a region of the Bordetella pertussis chromosome encoding filamentous hemagglutinin and the pleiotropic regulatory locus vir.

PubMed Central

Stibitz, S; Weiss, A A; Falkow, S

1988-01-01

The vir locus of Bordetella pertussis apparently encodes a trans-acting positive regulator that is required for the coordinate expression of genes associated with virulence: pertussis toxin, filamentous hemagglutinin (FHA), hemolysin, and adenylate cyclase toxin. DNA clones of vir and of genes required for the synthesis of some of the factors under vir control were obtained with DNA probes from the chromosomal DNA surrounding sites of Tn5 insertion mutations that inactivated those genes. Two vir clones were found which also contained genes required for the proper expression of FHA in B. pertussis. The plasmids which contained both the fha and vir genes expressed immunologically reactive FHA in Escherichia coli, as detected by colony blots, whereas plasmids which contained only fha or vir were negative in this assay. The regulation of FHA production in E. coli, as in B. pertussis, was temperature dependent and inhibited by high concentrations of either magnesium ions or nicotinic acid, indicating that the sequences cloned in E. coli contained the information required to preserve the physiological responses seen in B. pertussis. Further characterization of the vir-fha clones by Tn5 mutagenesis in E. coli and by the return of cloned sequences to B. pertussis in trans and to the B. pertussis chromosome led to the localization of the vir locus, the structural gene for FHA, and genes that are possibly required for the synthesis and export of FHA. Images PMID:2898470

Bipolar localization of the group II intron Ll.LtrB is maintained in Escherichia coli deficient in nucleoid condensation, chromosome partitioning and DNA replication.

PubMed

Beauregard, Arthur; Chalamcharla, Venkata R; Piazza, Carol Lyn; Belfort, Marlene; Coros, Colin J

2006-11-01

Group II introns are mobile genetic elements that invade their cognate intron-minus alleles via an RNA intermediate, in a process known as retrohoming. They can also retrotranspose to ectopic sites at low frequency. In Escherichia coli, retrotransposition of the lactococcal group II intron, Ll.LtrB, occurs preferentially within the Ori and Ter macrodomains of the E. coli chromosome. These macrodomains migrate towards the poles of the cell, where the intron-encoded protein, LtrA, localizes. Here we investigate whether alteration of nucleoid condensation, chromosome partitioning and replication affect retrotransposition frequencies, as well as bipolar localization of the Ll.LtrB intron integration and LtrA distribution in E. coli. We thus examined these properties in the absence of the nucleoid-associated proteins H-NS, StpA and MukB, in variants of partitioning functions including the centromere-like sequence migS and the actin homologue MreB, as well as in the replication mutants DeltaoriC, seqA, tus and topoIV (ts). Although there were some dramatic fluctuations in retrotransposition levels in these hosts, bipolar localization of integration events was maintained. LtrA was consistently found in nucleoid-free regions, with its localization to the cellular poles being largely preserved in these hosts. Together, these results suggest that bipolar localization of group II intron retrotransposition results from the residence of the intron-encoded protein at the poles of the cell.

Collinearity Analysis and High-Density Genetic Mapping of the Wheat Powdery Mildew Resistance Gene Pm40 in PI 672538

PubMed Central

Fatima, Syeda Akash; Yang, Jiezhi; Chen, Wanquan; Liu, Taiguo; Hu, Yuting; Li, Qing; Guo, Jingwei; Zhang, Min; Lei, Li; Li, Xin; Tang, Shengwen; Luo, Peigao

2016-01-01

The wheat powdery mildew resistance gene Pm40, which is located on chromosomal arm 7BS, is effective against nearly all prevalent races of Blumeria graminis f. sp tritici (Bgt) in China and is carried by the common wheat germplasm PI 672538. A set of the F1, F2 and F2:3 populations from the cross of the resistant PI 672538 with the susceptible line L1034 were used to conduct genetic analysis of powdery mildew resistance and construct a high-density linkage map of the Pm40 gene. We constructed a high-density linkage genetic map with a total length of 6.18 cM and average spacing between markers of 0.48 cM.Pm40 is flanked by Xwmc335 and BF291338 at genetic distances of 0.58 cM and 0.26 cM, respectively, in deletion bin C-7BS-1-0.27. Comparative genomic analysis based on EST-STS markers established a high level of collinearity of the Pm40 genomic region with a 1.09-Mbp genomic region on Brachypodium chromosome 3, a 1.16-Mbp genomic region on rice chromosome 8, and a 1.62-Mbp genomic region on sorghum chromosome 7. We further anchored the Pm40 target intervals to the wheat genome sequence. A putative linear index of 85 wheat contigs containing 97 genes on 7BS was constructed. In total, 9 genes could be considered as candidates for the resistances to powdery mildew in the target genomic regions, which encoded proteins that were involved in the plant defense and response to pathogen attack. These results will facilitate the development of new markers for map-based cloning and marker-assisted selection of Pm40 in wheat breeding programs. PMID:27755575

The sh2-R allele of the maize shrunken-2 locus was caused by a complex chromosomal rearrangement.

PubMed

Kramer, Vance; Shaw, Janine R; Senior, M Lynn; Hannah, L Curtis

2015-03-01

The mutant that originally defined the shrunken - 2 locus of maize is shown here to be the product of a complex chromosomal rearrangement. The maize shrunken-2 gene (sh2) encodes the large subunit of the heterotetrameric enzyme, adenosine diphosphate glucose pyrophosphorylases and a rate-limiting enzyme in starch biosynthesis. The sh2 gene was defined approximately 72 years ago by the isolation of a loss-of-function allele conditioning a shrunken, but viable seed. In subsequent years, the realization that this allele, termed zsh2-R or sh2-Reference, causes an extremely high level of sucrose to accumulate in the developing seed led to a revolution in the sweet corn industry. Now, the vast majority of sweet corns grown throughout the world contain this mutant allele. Through initial Southern analysis followed by genomic sequencing, the work reported here shows that this allele arose through a complex set of events involving at least three breaks of chromosome 3 as well as an intra-chromosomal inversion. These findings provide an explanation for some previously reported, unexpected observations concerning rates of recombination within and between genes in this region.

Bacteriophage-based vectors for site-specific insertion of DNA in the chromosome of Corynebacteria.

PubMed

Oram, Mark; Woolston, Joelle E; Jacobson, Andrew D; Holmes, Randall K; Oram, Diana M

2007-04-15

In Corynebacterium diphtheriae, diphtheria toxin is encoded by the tox gene of some temperate corynephages such as beta. beta-like corynephages are capable of inserting into the C. diphtheriae chromosome at two specific sites, attB1 and attB2. Transcription of the phage-encoded tox gene, and many chromosomally encoded genes, is regulated by the DtxR protein in response to Fe(2+) levels. Characterizing DtxR-dependent gene regulation is pivotal in understanding diphtheria pathogenesis and mechanisms of iron-dependent gene expression; although this has been hampered by a lack of molecular genetic tools in C. diphtheriae and related Coryneform species. To expand the systems for genetic manipulation of C. diphtheriae, we constructed plasmid vectors capable of integrating into the chromosome. These plasmids contain the beta-encoded attP site and the DIP0182 integrase gene of C. diphtheriae NCTC13129. When these vectors were delivered to the cytoplasm of non-lysogenic C. diphtheriae, they integrated into either the attB1 or attB2 sites with comparable frequency. Lysogens were also transformed with these vectors, by virtue of the second attB site. An integrated vector carrying an intact dtxR gene complemented the mutant phenotypes of a C. diphtheriae DeltadtxR strain. Additionally, strains of beta-susceptible C. ulcerans, and C. glutamicum, a species non-permissive for beta, were each transformed with these vectors. This work significantly extends the tools available for targeted transformation of both pathogenic and non-pathogenic Corynebacterium species.

Hd6, a rice quantitative trait locus involved in photoperiod sensitivity, encodes the α subunit of protein kinase CK2

PubMed Central

Takahashi, Yuji; Shomura, Ayahiko; Sasaki, Takuji; Yano, Masahiro

2001-01-01

Hd6 is a quantitative trait locus involved in rice photoperiod sensitivity. It was detected in backcross progeny derived from a cross between the japonica variety Nipponbare and the indica variety Kasalath. To isolate a gene at Hd6, we used a large segregating population for the high-resolution and fine-scale mapping of Hd6 and constructed genomic clone contigs around the Hd6 region. Linkage analysis with P1-derived artificial chromosome clone-derived DNA markers delimited Hd6 to a 26.4-kb genomic region. We identified a gene encoding the α subunit of protein kinase CK2 (CK2α) in this region. The Nipponbare allele of CK2α contains a premature stop codon, and the resulting truncated product is undoubtedly nonfunctional. Genetic complementation analysis revealed that the Kasalath allele of CK2α increases days-to-heading. Map-based cloning with advanced backcross progeny enabled us to identify a gene underlying a quantitative trait locus even though it exhibited a relatively small effect on the phenotype. PMID:11416158

Molecular characterization and genomic distribution of Isis: a new retrotransposon of Drosophila buzzatii.

PubMed

García Guerreiro, M P; Fontdevila, A

2007-01-01

A new transposable element, Isis, is identified as a LTR retrotransposon in Drosophila buzzatii. DNA sequence analysis shows that Isis contains three long ORFs similar to gag, pol and env genes of retroviruses. The ORF1 exhibits sequence homology to matrix, capsid and nucleocapsid gag proteins and ORF2 encodes a putative protease (PR), a reverse transcriptase (RT), an Rnase H (RH) and an integrase (IN) region. The analysis of a putative env product, encoded by the env ORF3, shows a degenerated protein containing several stop codons. The molecular study of the putative proteins coded by this new element shows striking similarities to both Ulysses and Osvaldo elements, two LTR retrotransposons, present in D. virilis and D. buzzatii, respectively. Comparisons of the predicted Isis RT to several known retrotransposons show strong phylogenetic relationships to gypsy-like elements, particulary to Ulysses retrotransposon. Studies of Isis chromosomal distribution show a strong hybridization signal in centromeric and pericentromeric regions, and a scattered distribution along all chromosomal arms. The existence of insertional polymorphisms between different strains and high molecular weight bands by Southern blot suggests the existence of full-sized copies that have been active recently. The presence of euchromatic insertion sites coincident between Isis and Osvaldo could indicate preferential insertion sites of Osvaldo element into Isis sequence or vice versa. Moreover, the presence of Isis in different species of the buzzatii complex indicates the ancient origin of this element.

Protection of CpG islands from DNA methylation is DNA-encoded and evolutionarily conserved

PubMed Central

Long, Hannah K.; King, Hamish W.; Patient, Roger K.; Odom, Duncan T.; Klose, Robert J.

2016-01-01

DNA methylation is a repressive epigenetic modification that covers vertebrate genomes. Regions known as CpG islands (CGIs), which are refractory to DNA methylation, are often associated with gene promoters and play central roles in gene regulation. Yet how CGIs in their normal genomic context evade the DNA methylation machinery and whether these mechanisms are evolutionarily conserved remains enigmatic. To address these fundamental questions we exploited a transchromosomic animal model and genomic approaches to understand how the hypomethylated state is formed in vivo and to discover whether mechanisms governing CGI formation are evolutionarily conserved. Strikingly, insertion of a human chromosome into mouse revealed that promoter-associated CGIs are refractory to DNA methylation regardless of host species, demonstrating that DNA sequence plays a central role in specifying the hypomethylated state through evolutionarily conserved mechanisms. In contrast, elements distal to gene promoters exhibited more variable methylation between host species, uncovering a widespread dependence on nucleotide frequency and occupancy of DNA-binding transcription factors in shaping the DNA methylation landscape away from gene promoters. This was exemplified by young CpG rich lineage-restricted repeat sequences that evaded DNA methylation in the absence of co-evolved mechanisms targeting methylation to these sequences, and species specific DNA binding events that protected against DNA methylation in CpG poor regions. Finally, transplantation of mouse chromosomal fragments into the evolutionarily distant zebrafish uncovered the existence of a mechanistically conserved and DNA-encoded logic which shapes CGI formation across vertebrate species. PMID:27084945

Targeted Quantitative Screening of Chromosome 18 Encoded Proteome in Plasma Samples of Astronaut Candidates.

PubMed

Kopylov, Artur T; Ilgisonis, Ekaterina V; Moysa, Alexander A; Tikhonova, Olga V; Zavialova, Maria G; Novikova, Svetlana E; Lisitsa, Andrey V; Ponomarenko, Elena A; Moshkovskii, Sergei A; Markin, Andrey A; Grigoriev, Anatoly I; Zgoda, Victor G; Archakov, Alexander I

2016-11-04

This work was aimed at estimating the concentrations of proteins encoded by human chromosome 18 (Chr 18) in plasma samples of 54 healthy male volunteers (aged 20-47). These young persons have been certified by the medical evaluation board as healthy subjects ready for space flight training. Over 260 stable isotope-labeled peptide standards (SIS) were synthesized to perform the measurements of proteins encoded by Chr 18. Selected reaction monitoring (SRM) with SIS allowed an estimate of the levels of 84 of 276 proteins encoded by Chr 18. These proteins were quantified in whole and depleted plasma samples. Concentration of the proteins detected varied from 10 -6 M (transthyretin, P02766) to 10 -11 M (P4-ATPase, O43861). A minor part of the proteins (mostly representing intracellular proteins) was characterized by extremely high inter individual variations. The results provide a background for studies of a potential biomarker in plasma among proteins encoded by Chr 18. The SRM raw data are available in ProteomeXchange repository (PXD004374).

Cloning and Expression of the Benzoate Dioxygenase Genes from Rhodococcus sp. Strain 19070

PubMed Central

Haddad, Sandra; Eby, D. Matthew; Neidle, Ellen L.

2001-01-01

The bopXYZ genes from the gram-positive bacterium Rhodococcus sp. strain 19070 encode a broad-substrate-specific benzoate dioxygenase. Expression of the BopXY terminal oxygenase enabled Escherichia coli to convert benzoate or anthranilate (2-aminobenzoate) to a nonaromatic cis-diol or catechol, respectively. This expression system also rapidly transformed m-toluate (3-methylbenzoate) to an unidentified product. In contrast, 2-chlorobenzoate was not a good substrate. The BopXYZ dioxygenase was homologous to the chromosomally encoded benzoate dioxygenase (BenABC) and the plasmid-encoded toluate dioxygenase (XylXYZ) of gram-negative acinetobacters and pseudomonads. Pulsed-field gel electrophoresis failed to identify any plasmid in Rhodococcus sp. strain 19070. Catechol 1,2- and 2,3-dioxygenase activity indicated that strain 19070 possesses both meta- and ortho-cleavage degradative pathways, which are associated in pseudomonads with the xyl and ben genes, respectively. Open reading frames downstream of bopXYZ, designated bopL and bopK, resembled genes encoding cis-diol dehydrogenases and benzoate transporters, respectively. The bop genes were in the same order as the chromosomal ben genes of P. putida PRS2000. The deduced sequences of BopXY were 50 to 60% identical to the corresponding proteins of benzoate and toluate dioxygenases. The reductase components of these latter dioxygenases, BenC and XylZ, are 201 residues shorter than the deduced BopZ sequence. As predicted from the sequence, expression of BopZ in E. coli yielded an approximately 60-kDa protein whose presence corresponded to increased cytochrome c reductase activity. While the N-terminal region of BopZ was approximately 50% identical in sequence to the entire BenC or XylZ reductases, the C terminus was unlike other known protein sequences. PMID:11375157

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

Cheng, J.; Liu, C.; Koopman, W.J.

Ligation of the Fas cell-surface molecule induces apoptosis. Defective Fas-mediated apoptosis has been associated with spontaneous autoimmunity in mice. Using human Fas/Apo-1 cDNA as a probe, the authors have molecularly cloned and characterized the human Fas chromosomal gene. The gene consists of nine exons and spans more than 26 kilobases of DNA. The lengths of introns vary from > 14 kilobases at the 5` end of the gene to 152 base pairs upstream of the exon encoding the transmembrane domain. The domain structure of the human Fas is encoded by an exon or a set of exons. Primer extension analysismore » revealed three major transcription initiation sites. The promoter region lacked canonical {open_quotes}TATA{close_quotes} and {open_quotes}CAAT{close_quotes} boxes but was a {open_quotes}GC-rich{close_quotes} sequence, and contained consensus sequences for AP-1, GF-1, NY-Y, CP-2, EBP20, and c-myb. These data provide the first characterization of the human Fas gene and insight into its regulatory region. 54 refs., 3 figs., 1 tab.« less

Identification of the centromere-specific histone H3 variant in Lotus japonicus.

PubMed

Tek, Ahmet L; Kashihara, Kazunari; Murata, Minoru; Nagaki, Kiyotaka

2014-03-15

The centromere is a structurally and functionally specialized region present on every eukaryotic chromosome. Lotus japonicus is a model legume species for which there is very limited information on the centromere structure. Here we cloned and characterized the L. japonicus homolog of the centromere-specific histone H3 gene (LjCenH3) encoding a 159-amino acid protein. Using an Agrobacterium-based transformation system, LjCenH3 tagged with a green fluorescent protein was transferred into L. japonicus cells. The centromeric position of LjCENH3 protein was revealed on L. japonicus metaphase chromosomes by an immunofluorescence assay. The identification of LjCenH3 as a critical centromere landmark could pave the way for a better understanding of centromere structure in this model and other agriculturally important legume species. Published by Elsevier B.V.

Transcriptome profiling of Nasonia vitripennis testis reveals novel transcripts expressed from the selfish B chromosome, paternal sex ratio.

PubMed

Akbari, Omar S; Antoshechkin, Igor; Hay, Bruce A; Ferree, Patrick M

2013-09-04

A widespread phenomenon in nature is sex ratio distortion of arthropod populations caused by microbial and genetic parasites. Currently little is known about how these agents alter host developmental processes to favor one sex or the other. The paternal sex ratio (PSR) chromosome is a nonessential, paternally transmitted centric fragment that segregates in natural populations of the jewel wasp, Nasonia vitripennis. To persist, PSR is thought to modify the hereditary material of the developing sperm, with the result that all nuclear DNA other than the PSR chromosome is destroyed shortly after fertilization. This results in the conversion of a fertilized embryo--normally a female--into a male, thereby insuring transmission of the "selfish" PSR chromosome, and simultaneously leading to wasp populations that are male-biased. To begin to understand this system at the mechanistic level, we carried out transcriptional profiling of testis from WT and PSR-carrying males. We identified a number of transcripts that are differentially expressed between these conditions. We also discovered nine transcripts that are uniquely expressed from the PSR chromosome. Four of these PSR-specific transcripts encode putative proteins, whereas the others have very short open reading frames and no homology to known proteins, suggesting that they are long noncoding RNAs. We propose several different models for how these transcripts could facilitate PSR-dependent effects. Our analyses also revealed 15.71 MB of novel transcribed regions in the N. vitripennis genome, thus increasing the current annotation of total transcribed regions by 53.4%. Finally, we detected expression of multiple meiosis-related genes in the wasp testis, despite the lack of conventional meiosis in the male sex.

Transcriptome Profiling of Nasonia vitripennis Testis Reveals Novel Transcripts Expressed from the Selfish B Chromosome, Paternal Sex Ratio

PubMed Central

Akbari, Omar S.; Antoshechkin, Igor; Hay, Bruce A.; Ferree, Patrick M.

2013-01-01

A widespread phenomenon in nature is sex ratio distortion of arthropod populations caused by microbial and genetic parasites. Currently little is known about how these agents alter host developmental processes to favor one sex or the other. The paternal sex ratio (PSR) chromosome is a nonessential, paternally transmitted centric fragment that segregates in natural populations of the jewel wasp, Nasonia vitripennis. To persist, PSR is thought to modify the hereditary material of the developing sperm, with the result that all nuclear DNA other than the PSR chromosome is destroyed shortly after fertilization. This results in the conversion of a fertilized embryo—normally a female—into a male, thereby insuring transmission of the “selfish” PSR chromosome, and simultaneously leading to wasp populations that are male-biased. To begin to understand this system at the mechanistic level, we carried out transcriptional profiling of testis from WT and PSR-carrying males. We identified a number of transcripts that are differentially expressed between these conditions. We also discovered nine transcripts that are uniquely expressed from the PSR chromosome. Four of these PSR-specific transcripts encode putative proteins, whereas the others have very short open reading frames and no homology to known proteins, suggesting that they are long noncoding RNAs. We propose several different models for how these transcripts could facilitate PSR-dependent effects. Our analyses also revealed 15.71 MB of novel transcribed regions in the N. vitripennis genome, thus increasing the current annotation of total transcribed regions by 53.4%. Finally, we detected expression of multiple meiosis-related genes in the wasp testis, despite the lack of conventional meiosis in the male sex. PMID:23893741

A genome-wide linkage scan for dietary energy and nutrient intakes: the Health, Risk Factors, Exercise Training, and Genetics (HERITAGE) Family Study.

PubMed

Collaku, Agron; Rankinen, Tuomo; Rice, Treva; Leon, Arthur S; Rao, D C; Skinner, James S; Wilmore, Jack H; Bouchard, Claude

2004-05-01

A poor diet is a risk factor for chronic diseases such as obesity, cardiovascular disease, hypertension, and some cancers. Twin and family studies suggest that genetic factors potentially influence energy and nutrient intakes. We sought to identify genomic regions harboring genes affecting total energy, carbohydrate, protein, and fat intakes. We performed a genomic scan in 347 white sibling pairs and 99 black sibling pairs. Dietary energy and nutrient intakes were assessed by using Willett's food-frequency questionnaire. Single-point and multipoint Haseman-Elston regression techniques were used to test for linkage. These subjects were part of the Health, Risk Factors, Exercise Training, and Genetics (HERITAGE) Family Study, a multicenter project undertaken by 5 laboratories. In the whites, the strongest evidence of linkage appeared for dietary energy and nutrient intakes on chromosomes 1p21.2 (P = 0.0002) and 20q13.13 (P = 0.00007), and that for fat intake appeared on chromosome 12q14.1 (P = 0.0013). The linkage evidence on chromosomes 1 and 20 related to total energy intake rather than to the intake of specific macronutrients. In the blacks, promising linkages for macronutrient intakes occurred on chromosomes 12q23-q24.21, 1q32.1, and 7q11.1. Several potential candidate genes are encoded in and around the linkage regions on chromosomes 1p21.2, 12q14.1, and 20q13.13. These are the first reported human quantitative trait loci for dietary energy and macronutrient intakes. Further study may refine these quantitative trait loci to identify potential candidate genes for energy and specific macronutrient intakes that would be amenable to more detailed molecular studies.

Capturing novel mouse genes encoding chromosomal and other nuclear proteins.

PubMed

Tate, P; Lee, M; Tweedie, S; Skarnes, W C; Bickmore, W A

1998-09-01

The burgeoning wealth of gene sequences contrasts with our ignorance of gene function. One route to assigning function is by determining the sub-cellular location of proteins. We describe the identification of mouse genes encoding proteins that are confined to nuclear compartments by splicing endogeneous gene sequences to a promoterless betageo reporter, using a gene trap approach. Mouse ES (embryonic stem) cell lines were identified that express betageo fusions located within sub-nuclear compartments, including chromosomes, the nucleolus and foci containing splicing factors. The sequences of 11 trapped genes were ascertained, and characterisation of endogenous protein distribution in two cases confirmed the validity of the approach. Three novel proteins concentrated within distinct chromosomal domains were identified, one of which appears to be a serine/threonine kinase. The sequence of a gene whose product co-localises with splicesome components suggests that this protein may be an E3 ubiquitin-protein ligase. The majority of the other genes isolated represent novel genes. This approach is shown to be a powerful tool for identifying genes encoding novel proteins with specific sub-nuclear localisations and exposes our ignorance of the protein composition of the nucleus. Motifs in two of the isolated genes suggest new links between cellular regulatory mechanisms (ubiquitination and phosphorylation) and mRNA splicing and chromosome structure/function.

Chronic lymphocytic leukemia-associated chromosomal abnormalities and miRNA deregulation.

PubMed

Kiefer, Yvonne; Schulte, Christoph; Tiemann, Markus; Bullerdiek, Joern

2012-01-01

Chronic lymphocytic leukemia is the most common leukemia in adults. By cytogenetic investigations major subgroups of the disease can be identified that reflect different routes of tumor development. Of these chromosomal deviations, trisomy 12 and deletions of parts of either the long arm of chromosome 13, the long arm of chromosome 11, or the short arm of chromosome 17 are most commonly detected. In some of these aberrations the molecular target has been identified as eg, ataxia telangiectasia mutated (ATM) in case of deletions of chromosomal region 11q22~23 and the genes encoding microRNAs miR-15a/16-1 as likely targets of deletions of chromosomal band 13q14.3. Of note, these aberrations do not characterize independent subgroups but often coexist within the metaphases of one tumor. Generally, complex aberrations are associated with a worse prognosis than simple karyotypic alterations. Due to smaller sizes of the missing segment the detection of recurrent deletions is not always possible by means of classical cytogenetics but requires more advanced techniques as in particular fluorescence in situ hybridization (FISH). Nevertheless, at this time it is not recommended to replace classical cytogenetics by FISH because this would miss additional information given by complex or secondary karyotypic alterations. However, the results of cytogenetic analyses allow the stratification of prognostic and predictive groups of the disease. Of these, the group characterized by deletions involving TP53 is clinically most relevant. In the future refined methods as eg, array-based comparative genomic hybridization will supplement the existing techniques to characterize CLL.

Complete genome sequence of Yersinia ruckeri str. CSF007-82, etiologic agent of enteric redmouth disease in salmonid fish

USDA-ARS?s Scientific Manuscript database

We present the complete, closed and finished chromosomal and extra-chromosomal genome sequences of Y. ruckeri strain CSF007-82, etiologic agent of enteric red mouth disease in salmonid fish. The chromosome is 3,799,036 bp with a G+C content of 47.5% and encodes 3,530 predicted CDS, 7 ribosomal opero...

Genome-Wide Analysis of bZIP-Encoding Genes in Maize

PubMed Central

Wei, Kaifa; Chen, Juan; Wang, Yanmei; Chen, Yanhui; Chen, Shaoxiang; Lin, Yina; Pan, Si; Zhong, Xiaojun; Xie, Daoxin

2012-01-01

In plants, basic leucine zipper (bZIP) proteins regulate numerous biological processes such as seed maturation, flower and vascular development, stress signalling and pathogen defence. We have carried out a genome-wide identification and analysis of 125 bZIP genes that exist in the maize genome, encoding 170 distinct bZIP proteins. This family can be divided into 11 groups according to the phylogenetic relationship among the maize bZIP proteins and those in Arabidopsis and rice. Six kinds of intron patterns (a–f) within the basic and hinge regions are defined. The additional conserved motifs have been identified and present the group specificity. Detailed three-dimensional structure analysis has been done to display the sequence conservation and potential distribution of the bZIP domain. Further, we predict the DNA-binding pattern and the dimerization property on the basis of the characteristic features in the basic and hinge regions and the leucine zipper, respectively, which supports our classification greatly and helps to classify 26 distinct subfamilies. The chromosome distribution and the genetic analysis reveal that 58 ZmbZIP genes are located in the segmental duplicate regions in the maize genome, suggesting that the segment chromosomal duplications contribute greatly to the expansion of the maize bZIP family. Across the 60 different developmental stages of 11 organs, three apparent clusters formed represent three kinds of different expression patterns among the ZmbZIP gene family in maize development. A similar but slightly different expression pattern of bZIPs in two inbred lines displays that 22 detected ZmbZIP genes might be involved in drought stress. Thirteen pairs and 143 pairs of ZmbZIP genes show strongly negative and positive correlations in the four distinct fungal infections, respectively, based on the expression profile and Pearson's correlation coefficient analysis. PMID:23103471

Fine mapping and candidate gene analysis of qFL-chr1, a fiber length QTL in cotton.

PubMed

Xu, Peng; Gao, Jin; Cao, Zhibin; Chee, Peng W; Guo, Qi; Xu, Zhenzhen; Paterson, Andrew H; Zhang, Xianggui; Shen, Xinlian

2017-06-01

A fiber length QTL, qFL-chr1, was fine mapped to a 0.9 cM interval of cotton chromosome 1. Two positional candidate genes showed positive correlation between gene expression level and fiber length. Prior analysis of a backcross-self mapping population derived from a cross between Gossypium hirsutum L. and G. barbadense L. revealed a QTL on chromosome 1 associated with increased fiber length (qFL-chr1), which was confirmed in three independent populations of near-isogenic introgression lines (NIILs). Here, a single NIIL, R01-40-08, was used to develop a large population segregating for the target region. Twenty-two PCR-based polymorphic markers used to genotype 1672 BC 4 F 2 plants identified 432 recombinants containing breakpoints in the target region. Substitution mapping using 141 informative recombinants narrowed the position of qFL-chr1 to a 1.0-cM interval between SSR markers MUSS084 and CIR018. To exclude possible effects of non-target introgressions on fiber length, different heterozygous BC 4 F 3 plants introgressed between SSR markers NAU3384 and CGR5144 were selected to develop sub-NILs. The qFL-chr1 was further mapped at 0.9-cM interval between MUSS422 and CIR018 by comparisons of sub-NIL phenotype, and increased fiber length by ~1 mm. The 2.38-Mb region between MUSS422 and CIR018 in G. barbadense contained 19 annotated genes. Expression levels of two of these genes, GOBAR07705 (encoding 1-aminocyclopropane-1-carboxylate synthase) and GOBAR25992 (encoding amino acid permease), were positively correlated with fiber length in a small F 2 population, supporting these genes as candidates for qFL-chr1.

Molecular variation and horizontal gene transfer of the homocysteine methyltransferase gene mmuM and its distribution in clinical pathogens.

PubMed

Ying, Jianchao; Wang, Huifeng; Bao, Bokan; Zhang, Ying; Zhang, Jinfang; Zhang, Cheng; Li, Aifang; Lu, Junwan; Li, Peizhen; Ying, Jun; Liu, Qi; Xu, Teng; Yi, Huiguang; Li, Jinsong; Zhou, Li; Zhou, Tieli; Xu, Zuyuan; Ni, Liyan; Bao, Qiyu

2015-01-01

The homocysteine methyltransferase encoded by mmuM is widely distributed among microbial organisms. It is the key enzyme that catalyzes the last step in methionine biosynthesis and plays an important role in the metabolism process. It also enables the microbial organisms to tolerate high concentrations of selenium in the environment. In this research, 533 mmuM gene sequences covering 70 genera of the bacteria were selected from GenBank database. The distribution frequency of mmuM is different in the investigated genera of bacteria. The mapping results of 160 mmuM reference sequences showed that the mmuM genes were found in 7 species of pathogen genomes sequenced in this work. The polymerase chain reaction products of one mmuM genotype (NC_013951 as the reference) were sequenced and the sequencing results confirmed the mapping results. Furthermore, 144 representative sequences were chosen for phylogenetic analysis and some mmuM genes from totally different genera (such as the genes between Escherichia and Klebsiella and between Enterobacter and Kosakonia) shared closer phylogenetic relationship than those from the same genus. Comparative genomic analysis of the mmuM encoding regions on plasmids and bacterial chromosomes showed that pKF3-140 and pIP1206 plasmids shared a 21 kb homology region and a 4.9 kb fragment in this region was in fact originated from the Escherichia coli chromosome. These results further suggested that mmuM gene did go through the gene horizontal transfer among different species or genera of bacteria. High-throughput sequencing combined with comparative genomics analysis would explore distribution and dissemination of the mmuM gene among bacteria and its evolution at a molecular level.

New Carbenicillin-Hydrolyzing β-Lactamase (CARB-7) from Vibrio cholerae Non-O1, Non-O139 Strains Encoded by the VCR Region of the V. cholerae Genome†

PubMed Central

Melano, Roberto; Petroni, Alejandro; Garutti, Alicia; Saka, Héctor Alex; Mange, Laura; Pasterán, Fernando; Rapoport, Melina; Rossi, Alicia; Galas, Marcelo

2002-01-01

In a previous study, an analysis of 77 ampicillin-nonsusceptible (resistant plus intermediate categories) strains of Vibrio cholerae non-O1, non-O139, isolated from aquatic environment and diarrheal stool, showed that all of them produced a β-lactamase with a pI of 5.4. Hybridization or amplification by PCR with a probe for blaTEM or primers for blaCARB gene families was negative. In this work, an environmental ampicillin-resistant strain from this sample, ME11762, isolated from a waterway in the west region of Argentina, was studied. The nucleotide sequence of the structural gene of the β-lactamase was determined by bidirectional sequencing of a Sau3AI fragment belonging to this isolate. The gene encodes a new 288-amino-acid protein, designated CARB-7, that shares 88.5% homology with the CARB-6 enzyme; an overall 83.2% homology with PSE-4, PSE-1, CARB-3, and the Proteus mirabilis N29 enzymes; and 79% homology with CARB-4 enzyme. The gene for this β-lactamase could not be transferred to Escherichia coli by conjugation. The nucleotide sequence of the flanking regions of the blaCARB-7 gene showed the occurrence of three 123-bp V. cholerae repeated sequences, all of which were found outside the predicted open reading frame. The upstream fragment of the blaCARB-7 gene shared 93% identity with a locus situated inside V. cholerae's chromosome 2. These results strongly suggest the chromosomal location of the blaCARB-7 gene, making this the first communication of a β-lactamase gene located on the VCR island of the V. cholerae genome. PMID:12069969

Genomic structure, promoter identification, and chromosomal mapping of a mouse nuclear orphan receptor expressed in embryos and adult testes

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

Lee, C.H.; Wei, Li-Na; Copeland, N.G.

We have isolated and characterized overlapping genomic clones containing the complete transcribed region of a newly isolated mouse cDNA encoding an orphan receptor expressed specifically in midgestation embryos and adult testis. This gene spans a distance of more than 50 kb and is organized into 13 exons. The transcription initiation site is located at the 158th nucleotide upstream from the translation initiation codon. All the exon/intron junction sequences follow the GT/AG rule. Based upon Northern blot analysis and the size of the transcribed region of the gene, its transcript was determined to be approximately 2.5 kb. Within approximately 500 hpmore » upstream from the transcription initiation site, several immune response regulatory elements were identified but no TATA box was located. This gene was mapped to the distal region of mouse chromosome 10 and its locus has been designated Tr2-11. Immunohistochemical studies show that the Tr2-11 protein is present mainly in advanced germ cell populations of mature testes and that Tr2-11 gene expression is dramatically decreased in vitamin A-depleted animals. 23 refs., 7 figs.« less

Insights into the transcriptional and translational mechanisms of linear organellar chromosomes in the box jellyfish Alatina alata (Cnidaria: Medusozoa: Cubozoa).

PubMed

Kayal, Ehsan; Bentlage, Bastian; Collins, Allen G

2016-09-01

In most animals, the mitochondrial genome is characterized by its small size, organization into a single circular molecule, and a relative conservation of the number of encoded genes. In box jellyfish (Cubozoa, Cnidaria), the mitochondrial genome is organized into 8 linear mito-chromosomes harboring between one and 4 genes each, including 2 extra protein-coding genes: mt-polB and orf314. Such an organization challenges the traditional view of mitochondrial DNA (mtDNA) expression in animals. In this study, we investigate the pattern of mitochondrial gene expression in the box jellyfish Alatina alata, as well as several key nuclear-encoded molecular pathways involved in the processing of mitochondrial gene transcription. Read coverage of DNA-seq data is relatively uniform for all 8 mito-chromosomes, suggesting that each mito-chromosome is present in equimolar proportion in the mitochondrion. Comparison of DNA and RNA-seq based assemblies indicates that mito-chromosomes are transcribed into individual transcripts in which the beginning and ending are highly conserved. Expression levels for mt-polB and orf314 are similar to those of other mitochondrial-encoded genes, which provides further evidence for them having functional roles in the mitochondrion. Survey of the transcriptome suggests recognition of the mitochondrial tRNA-Met by the cytoplasmic aminoacyl-tRNA synthetase counterpart and C-to-U editing of the cytoplasmic tRNA-Trp after import into the mitochondrion. Moreover, several mitochondrial ribosomal proteins appear to be lost. This study represents the first survey of mitochondrial gene expression of the linear multi-chromosomal mtDNA in box jellyfish (Cubozoa). Future exploration of small RNAs and the proteome of the mitochondrion will test the hypotheses presented herein.

Bacteriophage-based Vectors for Site-specific Insertion of DNA in the Chromosome of Corynebacteria

PubMed Central

Oram, Mark; Woolston, Joelle E.; Jacobson, Andrew D.; Holmes, Randall K.; Oram, Diana M.

2007-01-01

In Corynebacterium diphtheriae, diphtheria toxin is encoded by the tox gene of some temperate corynephages such as β. β-like corynephages are capable of inserting into the C. diphtheriae chromosome at two specific sites, attB1 and attB2. Transcription of the phage-encoded tox gene, and many chromosomally-encoded genes, is regulated by the DtxR protein in response to Fe2+ levels. Characterizing DtxR-dependent gene regulation is pivotal in understanding diphtheria pathogenesis and mechanisms of iron-dependent gene expression; although this has been hampered by a lack of molecular genetic tools in C. diphtheriae and related Coryneform species. To expand the systems for genetic manipulation of C. diphtheriae, we constructed plasmid vectors capable of integrating into the chromosome. These plasmids contain the β-encoded attP site and the DIP0182 integrase gene of C. diphtheriae NCTC13129. When these vectors were delivered to the cytoplasm of non-lysogenic C. diphtheriae, they integrated into either the attB1 or attB2 sites with comparable frequency. Lysogens were also transformed with these vectors, by virtue of the second attB site. An integrated vector carrying an intact dtxR gene complemented the mutant phenotypes of a C. diphtheriae ΔdtxR strain. Additionally, strains of β-susceptible C. ulcerans, and C. glutamicum, a species non-permissive for β, were each transformed with these vectors. This work significantly extends the tools available for targeted transformation of both pathogenic and non-pathogenic Corynebacterium species. PMID:17275217

Characterization of a chromosomally encoded 2,4-dichlorophenoxyacetic acid/alpha-ketoglutarate dioxygenase from Burkholderia sp. strain RASC.

PubMed Central

Suwa, Y; Wright, A D; Fukimori, F; Nummy, K A; Hausinger, R P; Holben, W E; Forney, L J

1996-01-01

The findings of previous studies indicate that the genes required for metabolism of the pesticide 2,4-dichlorophenoxyacetic acid (2,4-D) are typically encoded on broad-host-range plasmids. However, characterization of plasmid-cured strains of Burkholderia sp. strain RASC, as well as mutants obtained by transposon mutagenesis, suggested that the 2,4-D catabolic genes were located on the chromosome of this strain. Mutants of Burkholderia strain RASC unable to degrade 2,4-D (2,4-D- strains) were obtained by insertional inactivation with Tn5. One such mutant (d1) was shown to have Tn5 inserted in tfdARASC, which encodes 2,4-D/alpha-ketoglutarate dioxygenase. This is the first reported example of a chromosomally encoded tfdA. The tfdARASC gene was cloned from a library of wild-type Burkholderia strain RASC DNA and shown to express 2,4-D/alpha-ketoglutarate dioxygenase activity in Escherichia coli. The DNA sequence of the gene was determined and shown to be similar, although not identical, to those of isofunctional genes from other bacteria. Moreover, the gene product (TfdARASC) was purified and shown to be similar in molecular weight, amino-terminal sequence, and reaction mechanism to the canonical TfdA of Alcaligenes eutrophus JMP134. The data presented here indicate that tfdA genes can be found on the chromosome of some bacterial species and suggest that these catabolic genes are rather mobile and may be transferred by means other than conjugation. PMID:8779585

The Spanish biology/disease initiative within the human proteome project: Application to rheumatic diseases.

PubMed

Ruiz-Romero, Cristina; Calamia, Valentina; Albar, Juan Pablo; Casal, José Ignacio; Corrales, Fernando J; Fernández-Puente, Patricia; Gil, Concha; Mateos, Jesús; Vivanco, Fernando; Blanco, Francisco J

2015-09-08

The Spanish Chromosome 16 consortium is integrated in the global initiative Human Proteome Project, which aims to develop an entire map of the proteins encoded following a gene-centric strategy (C-HPP) in order to make progress in the understanding of human biology in health and disease (B/D-HPP). Chromosome 16 contains many genes encoding proteins involved in the development of a broad range of diseases, which have a significant impact on the health care system. The Spanish HPP consortium has developed a B/D platform with five programs focused on selected medical areas: cancer, obesity, cardiovascular, infectious and rheumatic diseases. Each of these areas has a clinical leader associated to a proteomic investigator with the responsibility to get a comprehensive understanding of the proteins encoded by Chromosome 16 genes. Proteomics strategies have enabled great advances in the area of rheumatic diseases, particularly in osteoarthritis, with studies performed on joint cells, tissues and fluids. In this manuscript we describe how the Spanish HPP-16 consortium has developed a B/D platform with five programs focused on selected medical areas: cancer, obesity, cardiovascular, infectious and rheumatic diseases. Each of these areas has a clinical leader associated to a proteomic investigator with the responsibility to get a comprehensive understanding of the proteins encoded by Chromosome 16 genes. We show how the Proteomic strategy has enabled great advances in the area of rheumatic diseases, particularly in osteoarthritis, with studies performed on joint cells, tissues and fluids. This article is part of a Special Issue entitled: HUPO 2014. Copyright © 2015 Elsevier B.V. All rights reserved.

A new lead from genetic studies in depressed siblings: assessing studies of chromosome 3.

PubMed

Hamilton, Steven P

2011-08-01

Studies by Breen et al. and Pergadia et al. find evidence for genetic linkage between major depressive disorder and the same region on chromosome 3. The linked region contains the gene GRM7, which encodes a protein for the metabotropic glutamate receptor 7 (mGluR7). Both studies used affected sibling pairs, and neither was able to replicate its finding using association studies in individuals from larger population-based studies. Other family-based studies have also failed to find a signal in this region. Furthermore, there are some differences in how the phenotype was classified, with Breen et al. finding evidence only in the most severely affected patients. Nonetheless, the finding is not without other substantive support. A meta-analysis of 3,957 case subjects with major depressive disorder and 3,428 control subjects from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D), Genetics of Recurrent Early-onset Depression (GenRED), and the Genetic Association Information Network-MDD (GAIN-MDD) data sets demonstrated a region of association for major depressive disorder within GRM7. Thus, the significance of this finding remains uncertain, although it points to a gene that might hold significant promise for further developments in studying the pathophysiology and treatment of major depressive disorder.

Genome-Wide Association Mapping of Flowering and Ripening Periods in Apple.

PubMed

Urrestarazu, Jorge; Muranty, Hélène; Denancé, Caroline; Leforestier, Diane; Ravon, Elisa; Guyader, Arnaud; Guisnel, Rémi; Feugey, Laurence; Aubourg, Sébastien; Celton, Jean-Marc; Daccord, Nicolas; Dondini, Luca; Gregori, Roberto; Lateur, Marc; Houben, Patrick; Ordidge, Matthew; Paprstein, Frantisek; Sedlak, Jiri; Nybom, Hilde; Garkava-Gustavsson, Larisa; Troggio, Michela; Bianco, Luca; Velasco, Riccardo; Poncet, Charles; Théron, Anthony; Moriya, Shigeki; Bink, Marco C A M; Laurens, François; Tartarini, Stefano; Durel, Charles-Eric

2017-01-01

Deciphering the genetic control of flowering and ripening periods in apple is essential for breeding cultivars adapted to their growing environments. We implemented a large Genome-Wide Association Study (GWAS) at the European level using an association panel of 1,168 different apple genotypes distributed over six locations and phenotyped for these phenological traits. The panel was genotyped at a high-density of SNPs using the Axiom®Apple 480 K SNP array. We ran GWAS with a multi-locus mixed model (MLMM), which handles the putatively confounding effect of significant SNPs elsewhere on the genome. Genomic regions were further investigated to reveal candidate genes responsible for the phenotypic variation. At the whole population level, GWAS retained two SNPs as cofactors on chromosome 9 for flowering period, and six for ripening period (four on chromosome 3, one on chromosome 10 and one on chromosome 16) which, together accounted for 8.9 and 17.2% of the phenotypic variance, respectively. For both traits, SNPs in weak linkage disequilibrium were detected nearby, thus suggesting the existence of allelic heterogeneity. The geographic origins and relationships of apple cultivars accounted for large parts of the phenotypic variation. Variation in genotypic frequency of the SNPs associated with the two traits was connected to the geographic origin of the genotypes (grouped as North+East, West and South Europe), and indicated differential selection in different growing environments. Genes encoding transcription factors containing either NAC or MADS domains were identified as major candidates within the small confidence intervals computed for the associated genomic regions. A strong microsynteny between apple and peach was revealed in all the four confidence interval regions. This study shows how association genetics can unravel the genetic control of important horticultural traits in apple, as well as reduce the confidence intervals of the associated regions identified by linkage mapping approaches. Our findings can be used for the improvement of apple through marker-assisted breeding strategies that take advantage of the accumulating additive effects of the identified SNPs.

Precision-engineering the Pseudomonas aeruginosa genome with two-step allelic exchange

PubMed Central

Hmelo, Laura R.; Borlee, Bradley R.; Almblad, Henrik; Love, Michelle E.; Randall, Trevor E.; Tseng, Boo Shan; Lin, Chuyang; Irie, Yasuhiko; Storek, Kelly M.; Yang, Jaeun Jane; Siehnel, Richard J.; Howell, P. Lynne; Singh, Pradeep K.; Tolker-Nielsen, Tim; Parsek, Matthew R.; Schweizer, Herbert P.; Harrison, Joe J.

2016-01-01

Allelic exchange is an efficient method of bacterial genome engineering. This protocol describes the use of this technique to make gene knockouts and knockins, as well as single nucleotide insertions, deletions and substitutions in Pseudomonas aeruginosa. Unlike other approaches to allelic exchange, this protocol does not require heterologous recombinases to insert or excise selective markers from the target chromosome. Rather, positive and negative selection are enabled solely by suicide vector-encoded functions and host cell proteins. Here, mutant alleles, which are flanked by regions of homology to the recipient chromosome, are synthesized in vitro and then cloned into allelic exchange vectors using standard procedures. These suicide vectors are then introduced into recipient cells by conjugation. Homologous recombination then results in antibiotic resistant single-crossover mutants in which the plasmid has integrated site-specifically into the chromosome. Subsequently, unmarked double-crossover mutants are isolated directly using sucrose-mediated counter-selection. This two-step process yields seamless mutations that are precise to a single base pair of DNA. The entire procedure requires ~2 weeks. PMID:26492139

Mitochondrial genome deletions and minicircles are common in lice (Insecta: Phthiraptera)

PubMed Central

2011-01-01

Background The gene composition, gene order and structure of the mitochondrial genome are remarkably stable across bilaterian animals. Lice (Insecta: Phthiraptera) are a major exception to this genomic stability in that the canonical single chromosome with 37 genes found in almost all other bilaterians has been lost in multiple lineages in favour of multiple, minicircular chromosomes with less than 37 genes on each chromosome. Results Minicircular mt genomes are found in six of the ten louse species examined to date and three types of minicircles were identified: heteroplasmic minicircles which coexist with full sized mt genomes (type 1); multigene chromosomes with short, simple control regions, we infer that the genome consists of several such chromosomes (type 2); and multiple, single to three gene chromosomes with large, complex control regions (type 3). Mapping minicircle types onto a phylogenetic tree of lice fails to show a pattern of their occurrence consistent with an evolutionary series of minicircle types. Analysis of the nuclear-encoded, mitochondrially-targetted genes inferred from the body louse, Pediculus, suggests that the loss of mitochondrial single-stranded binding protein (mtSSB) may be responsible for the presence of minicircles in at least species with the most derived type 3 minicircles (Pediculus, Damalinia). Conclusions Minicircular mt genomes are common in lice and appear to have arisen multiple times within the group. Life history adaptive explanations which attribute minicircular mt genomes in lice to the adoption of blood-feeding in the Anoplura are not supported by this expanded data set as minicircles are found in multiple non-blood feeding louse groups but are not found in the blood-feeding genus Heterodoxus. In contrast, a mechanist explanation based on the loss of mtSSB suggests that minicircles may be selectively favoured due to the incapacity of the mt replisome to synthesize long replicative products without mtSSB and thus the loss of this gene lead to the formation of minicircles in lice. PMID:21813020

Mitochondrial genome deletions and minicircles are common in lice (Insecta: Phthiraptera).

PubMed

Cameron, Stephen L; Yoshizawa, Kazunori; Mizukoshi, Atsushi; Whiting, Michael F; Johnson, Kevin P

2011-08-04

The gene composition, gene order and structure of the mitochondrial genome are remarkably stable across bilaterian animals. Lice (Insecta: Phthiraptera) are a major exception to this genomic stability in that the canonical single chromosome with 37 genes found in almost all other bilaterians has been lost in multiple lineages in favour of multiple, minicircular chromosomes with less than 37 genes on each chromosome. Minicircular mt genomes are found in six of the ten louse species examined to date and three types of minicircles were identified: heteroplasmic minicircles which coexist with full sized mt genomes (type 1); multigene chromosomes with short, simple control regions, we infer that the genome consists of several such chromosomes (type 2); and multiple, single to three gene chromosomes with large, complex control regions (type 3). Mapping minicircle types onto a phylogenetic tree of lice fails to show a pattern of their occurrence consistent with an evolutionary series of minicircle types. Analysis of the nuclear-encoded, mitochondrially-targetted genes inferred from the body louse, Pediculus, suggests that the loss of mitochondrial single-stranded binding protein (mtSSB) may be responsible for the presence of minicircles in at least species with the most derived type 3 minicircles (Pediculus, Damalinia). Minicircular mt genomes are common in lice and appear to have arisen multiple times within the group. Life history adaptive explanations which attribute minicircular mt genomes in lice to the adoption of blood-feeding in the Anoplura are not supported by this expanded data set as minicircles are found in multiple non-blood feeding louse groups but are not found in the blood-feeding genus Heterodoxus. In contrast, a mechanist explanation based on the loss of mtSSB suggests that minicircles may be selectively favoured due to the incapacity of the mt replisome to synthesize long replicative products without mtSSB and thus the loss of this gene lead to the formation of minicircles in lice.

Genome-wide association analyses of child genotype effects and parent-of-origin effects in specific language impairment.

PubMed

Nudel, R; Simpson, N H; Baird, G; O'Hare, A; Conti-Ramsden, G; Bolton, P F; Hennessy, E R; Ring, S M; Davey Smith, G; Francks, C; Paracchini, S; Monaco, A P; Fisher, S E; Newbury, D F

2014-04-01

Specific language impairment (SLI) is a neurodevelopmental disorder that affects linguistic abilities when development is otherwise normal. We report the results of a genome-wide association study of SLI which included parent-of-origin effects and child genotype effects and used 278 families of language-impaired children. The child genotype effects analysis did not identify significant associations. We found genome-wide significant paternal parent-of-origin effects on chromosome 14q12 (P = 3.74 × 10(-8)) and suggestive maternal parent-of-origin effects on chromosome 5p13 (P = 1.16 × 10(-7)). A subsequent targeted association of six single-nucleotide-polymorphisms (SNPs) on chromosome 5 in 313 language-impaired individuals and their mothers from the ALSPAC cohort replicated the maternal effects, albeit in the opposite direction (P = 0.001); as fathers' genotypes were not available in the ALSPAC study, the replication analysis did not include paternal parent-of-origin effects. The paternally-associated SNP on chromosome 14 yields a non-synonymous coding change within the NOP9 gene. This gene encodes an RNA-binding protein that has been reported to be significantly dysregulated in individuals with schizophrenia. The region of maternal association on chromosome 5 falls between the PTGER4 and DAB2 genes, in a region previously implicated in autism and ADHD. The top SNP in this association locus is a potential expression QTL of ARHGEF19 (also called WGEF) on chromosome 1. Members of this protein family have been implicated in intellectual disability. In summary, this study implicates parent-of-origin effects in language impairment, and adds an interesting new dimension to the emerging picture of shared genetic etiology across various neurodevelopmental disorders. © 2014 The Authors. Genes, Brain and Behavior published by International Behavioural and Neural Genetics Society and John Wiley & Sons Ltd.

Transcript Profiling Reveals New Insights into the Acclimation of the Mesophilic Fresh-Water Cyanobacterium Synechococcus elongatus PCC 7942 to Iron Starvation1[W

PubMed Central

Nodop, Anke; Pietsch, Daniel; Höcker, Ralf; Becker, Anke; Pistorius, Elfriede K.; Forchhammer, Karl; Michel, Klaus-Peter

2008-01-01

The regulatory network for acclimation of the obligate photoautotrophic fresh water cyanobacterium Synechococcus elongatus PCC 7942 to iron (Fe) limitation was studied by transcript profiling with an oligonucleotide whole genome DNA microarray. Six regions on the chromosome with several Fe-regulated genes each were identified. The irpAB and fut region encode putative Fe uptake systems, the suf region participates in [Fe-sulfur] cluster assembly under oxidative stress and Fe limitation, the isiAB region encodes CP43′ and flavodoxin, the idiCB region encodes the NuoE-like electron transport associated protein IdiC and the transcriptional activator IdiB, and the ackA/pgam region encodes an acetate kinase and a phosphoglycerate mutase. We also investigated the response of two S. elongatus PCC 7942 mutants to Fe starvation. These were mutant K10, lacking IdiB but containing IdiC, and mutant MuD, representing a idiC-merodiploid mutant with a strongly reduced amount of IdiC as well as IdiB. The absence of IdiB in mutant K10 or the strongly reduced amount of IdiB in mutant MuD allowed for the identification of additional members of the Fe-responsive IdiB regulon. Besides idiA and the irpAB operon somB(1), somA(2), ftr1, ackA, pgam, and nat also seem to be regulated by IdiB. In addition to the reduced amount of IdiB in MuD, the low concentration of IdiC may be responsible for a number of additional changes in the abundance of mainly photosynthesis-related transcripts as compared to the wild type and mutant K10. This fact may explain why it has been impossible to obtain a fully segregated IdiC-free mutant, whereas it was possible to obtain a fully segregated IdiB-free mutant. PMID:18424627

Isolation, expression, and chromosomal localization of the human mitochondrial capsule selenoprotein gene (MCSP)

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

Aho, Hanne; Schwemmer, M.; Tessmann, D.

1996-03-01

The mitochondrial capsule selenoprotein (MCS) (HGMW-approved symbol MCSP) is one of three proteins that are important for the maintenance and stabilization of the crescent structure of the sperm mitochondria. We describe here the isolation of a cDNA, the exon-intron organization, the expression, and the chromosomal localization of the human MCS gene. Nucleotide sequence analysis of the human and mouse MCS cDNAs reveals that the 5{prime}- and 3{prime}-untranslated sequences are more conserved (71%) than the coding sequences (59%). The open reading frame encodes a 116-amino-acid protein and lacks the UGA codons, which have been reported to encode the selenocysteines in themore » N-terminal of the deduced mouse protein. The deduced human protein shows a low degree of amino acid sequence identity to the mouse protein. The deduced human protein shows a low degree of amino acid sequence identity to the mouse protein (39%). The most striking homology lies in the dicysteine motifs. Northern and Southern zooblot analyses reveal that the MCS gene in human, baboon, and bovine is more conserved than its counterparts in mouse and rat. The single intron in the human MCS gene is approximately 6 kb and interrupts the 5{prime}-untranslated region at a position equivalent to that in the mouse and rat genes. Northern blot and in situ hybridization experiments demonstrate that the expression of the human MCS gene is restricted to haploid spermatids. The human gene was assigned to q21 of chromosome 1. 30 refs., 9 figs.« less

Cloning, characterization, and chromosomal mapping of a human electroneutral Na(+)-driven Cl-HCO3 exchanger.

PubMed

Grichtchenko, I I; Choi, I; Zhong, X; Bray-Ward, P; Russell, J M; Boron, W F

2001-03-16

The electroneutral Na(+)-driven Cl-HCO3 exchanger is a key mechanism for regulating intracellular pH (pH(i)) in neurons, glia, and other cells. Here we report the cloning, tissue distribution, chromosomal location, and functional characterization of the cDNA of such a transporter (NDCBE1) from human brain (GenBank accession number AF069512). NDCBE1, which encodes 1044 amino acids, is 34% identical to the mammalian anion exchanger (AE2); approximately 50% to the electrogenic Na/HCO3 cotransporter (NBCe1) from salamander, rat, and humans; approximately 73% to mammalian electroneutral Na/HCO3 cotransporters (NBCn1); 71% to mouse NCBE; and 47% to a Na(+)-driven anion exchanger (NDAE1) from Drosophila. Northern blot analysis of NDCBE1 shows a robust approximately 12-kilobase signal in all major regions of human brain and in testis, and weaker signals in kidney and ovary. This human gene (SLC4A8) maps to chromosome 12q13. When expressed in Xenopus oocytes and running in the forward direction, NDCBE1 is electroneutral and mediates increases in both pH(i) and [Na(+)](i) (monitored with microelectrodes) that require HCO3(-) and are blocked by 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS). The pH(i) increase also requires extracellular Na(+). The Na(+):HCO3(-) stoichiometry is 1:2. Forward-running NDCBE1 mediates a 36Cl efflux that requires extracellular Na(+) and HCO3(-) and is blocked by DIDS. Running in reverse, NDCBE1 requires extracellular Cl(-). Thus, NDCBE1 encodes a human, electroneutral Na(+)-driven Cl-HCO3 exchanger.

Mutation screening of patients with Alzheimer disease identifies APP locus duplication in a Swedish patient

PubMed Central

2011-01-01

Background Missense mutations in three different genes encoding amyloid-β precursor protein, presenilin 1 and presenilin 2 are recognized to cause familial early-onset Alzheimer disease. Also duplications of the amyloid precursor protein gene have been shown to cause the disease. At the Dept. of Geriatric Medicine, Karolinska University Hospital, Sweden, patients are referred for mutation screening for the identification of nucleotide variations and for determining copy-number of the APP locus. Methods We combined the method of microsatellite marker genotyping with a quantitative real-time PCR analysis to detect duplications in patients with Alzheimer disease. Results In 22 DNA samples from individuals diagnosed with clinical Alzheimer disease, we identified one patient carrying a duplication on chromosome 21 which included the APP locus. Further mapping of the chromosomal region by array-comparative genome hybridization showed that the duplication spanned a maximal region of 1.09 Mb. Conclusions This is the first report of an APP duplication in a Swedish Alzheimer patient and describes the use of quantitative real-time PCR as a tool for determining copy-number of the APP locus. PMID:22044463

Mutation screening of patients with Alzheimer disease identifies APP locus duplication in a Swedish patient.

PubMed

Thonberg, Håkan; Fallström, Marie; Björkström, Jenny; Schoumans, Jacqueline; Nennesmo, Inger; Graff, Caroline

2011-11-01

Missense mutations in three different genes encoding amyloid-β precursor protein, presenilin 1 and presenilin 2 are recognized to cause familial early-onset Alzheimer disease. Also duplications of the amyloid precursor protein gene have been shown to cause the disease. At the Dept. of Geriatric Medicine, Karolinska University Hospital, Sweden, patients are referred for mutation screening for the identification of nucleotide variations and for determining copy-number of the APP locus. We combined the method of microsatellite marker genotyping with a quantitative real-time PCR analysis to detect duplications in patients with Alzheimer disease. In 22 DNA samples from individuals diagnosed with clinical Alzheimer disease, we identified one patient carrying a duplication on chromosome 21 which included the APP locus. Further mapping of the chromosomal region by array-comparative genome hybridization showed that the duplication spanned a maximal region of 1.09 Mb. This is the first report of an APP duplication in a Swedish Alzheimer patient and describes the use of quantitative real-time PCR as a tool for determining copy-number of the APP locus.

Methylotrophic Bacillus methanolicus Encodes Two Chromosomal and One Plasmid Born NAD+ Dependent Methanol Dehydrogenase Paralogs with Different Catalytic and Biochemical Properties

PubMed Central

Müller, Jonas E. N.; Kupper, Christiane E.; Schneider, Olha; Vorholt, Julia A.; Ellingsen, Trond E.; Brautaset, Trygve

2013-01-01

Bacillus methanolicus can utilize methanol as the sole carbon source for growth and it encodes an NAD+-dependent methanol dehydrogenase (Mdh), catalyzing the oxidation of methanol to formaldehyde. Recently, the genomes of the B. methanolicus strains MGA3 (ATCC53907) and PB1 (NCIMB13113) were sequenced and found to harbor three different putative Mdh encoding genes, each belonging to the type III Fe-NAD+-dependent alcohol dehydrogenases. In each strain, two of these genes are encoded on the chromosome and one on a plasmid; only one chromosomal act gene encoding the previously described activator protein ACT was found. The six Mdhs and the ACT proteins were produced recombinantly in Escherichia coli, purified, and characterized. All Mdhs required NAD+ as cosubstrate, were catalytically stimulated by ACT, exhibited a broad and different substrate specificity range and displayed both dehydrogenase and reductase activities. All Mdhs catalyzed the oxidation of methanol; however the catalytic activity for methanol was considerably lower than for most other alcohols tested, suggesting that these enzymes represent a novel class of alcohol dehydrogenases. The kinetic constants for the Mdhs were comparable when acting as pure enzymes, but together with ACT the differences were more pronounced. Quantitative PCR experiments revealed major differences with respect to transcriptional regulation of the paralogous genes. Taken together our data indicate that the repertoire of methanol oxidizing enzymes in thermotolerant bacilli is larger than expected with complex mechanisms involved in their regulation. PMID:23527128

Methylotrophic Bacillus methanolicus encodes two chromosomal and one plasmid born NAD+ dependent methanol dehydrogenase paralogs with different catalytic and biochemical properties.

PubMed

Krog, Anne; Heggeset, Tonje M B; Müller, Jonas E N; Kupper, Christiane E; Schneider, Olha; Vorholt, Julia A; Ellingsen, Trond E; Brautaset, Trygve

2013-01-01

Bacillus methanolicus can utilize methanol as the sole carbon source for growth and it encodes an NAD(+)-dependent methanol dehydrogenase (Mdh), catalyzing the oxidation of methanol to formaldehyde. Recently, the genomes of the B. methanolicus strains MGA3 (ATCC53907) and PB1 (NCIMB13113) were sequenced and found to harbor three different putative Mdh encoding genes, each belonging to the type III Fe-NAD(+)-dependent alcohol dehydrogenases. In each strain, two of these genes are encoded on the chromosome and one on a plasmid; only one chromosomal act gene encoding the previously described activator protein ACT was found. The six Mdhs and the ACT proteins were produced recombinantly in Escherichia coli, purified, and characterized. All Mdhs required NAD(+) as cosubstrate, were catalytically stimulated by ACT, exhibited a broad and different substrate specificity range and displayed both dehydrogenase and reductase activities. All Mdhs catalyzed the oxidation of methanol; however the catalytic activity for methanol was considerably lower than for most other alcohols tested, suggesting that these enzymes represent a novel class of alcohol dehydrogenases. The kinetic constants for the Mdhs were comparable when acting as pure enzymes, but together with ACT the differences were more pronounced. Quantitative PCR experiments revealed major differences with respect to transcriptional regulation of the paralogous genes. Taken together our data indicate that the repertoire of methanol oxidizing enzymes in thermotolerant bacilli is larger than expected with complex mechanisms involved in their regulation.

Comparative sequence analysis revealed altered chromosomal organization and a novel insertion sequence encoding DNA modification and potentially stress-related functions in an Escherichia coli O157:H7 foodborne isolate

USDA-ARS?s Scientific Manuscript database

We recently described the complete genome of enterohemorrhagic Escherichia coli (EHEC) O157:H7 strain NADC 6564, an isolate of strain 86-24 linked to the 1986 disease outbreak. In the current study, we compared the chromosomal sequence of NADC 6564 to the well-characterized chromosomal sequences of ...

Characterization of a complex context containing mecA but lacking genes encoding cassette chromosome recombinases in Staphylococcus haemolyticus

PubMed Central

2013-01-01

Background Methicillin resistance determinant mecA is generally transferred by SCCmec elements. However, the mecA gene might not be carried by a SCCmec in a Staphylococcus haemolyticus clinical isolate, WCH1, as no cassette chromosome recombinase genes were detected. Therefore, the genetic context of mecA in WCH1 was investigated. Results A 40-kb region containing mecA was obtained from WCH1, bounded by orfX at one end and several orfs of S. haemolyticus core chromosome at the other. This 40-kb region was very complex in structure with multiple genetic components that appeared to have different origins. For instance, the 3.7-kb structure adjacent to orfX was almost identical to that on the chromosome of Staphylococcus epidermidis RP62a but was absent from S. haemolyticus JCSC1435. Terminal inverted repeats of SCC were found but no ccr genes could be detected. mecA was bracketed by two copies of IS431, which was flanked by 8-bp direct target repeat sequence (DR). Conclusions The presence of 8-bp DR suggests that the two copies of IS431 might have formed a composite transposon for mobilizing mecA. This finding is of significance as multiple copies of IS431 are commonly present in the contexts of mecA, which might have the potential to form various composite transposons that could mediate the mobilization of mecA. This study also provides an explanation for the absence of ccr in some staphylococci isolates carrying mecA. PMID:23521926

Characterization of a complex context containing mecA but lacking genes encoding cassette chromosome recombinases in Staphylococcus haemolyticus.

PubMed

Zong, Zhiyong

2013-03-22

Methicillin resistance determinant mecA is generally transferred by SCCmec elements. However, the mecA gene might not be carried by a SCCmec in a Staphylococcus haemolyticus clinical isolate, WCH1, as no cassette chromosome recombinase genes were detected. Therefore, the genetic context of mecA in WCH1 was investigated. A 40-kb region containing mecA was obtained from WCH1, bounded by orfX at one end and several orfs of S. haemolyticus core chromosome at the other. This 40-kb region was very complex in structure with multiple genetic components that appeared to have different origins. For instance, the 3.7-kb structure adjacent to orfX was almost identical to that on the chromosome of Staphylococcus epidermidis RP62a but was absent from S. haemolyticus JCSC1435. Terminal inverted repeats of SCC were found but no ccr genes could be detected. mecA was bracketed by two copies of IS431, which was flanked by 8-bp direct target repeat sequence (DR). The presence of 8-bp DR suggests that the two copies of IS431 might have formed a composite transposon for mobilizing mecA. This finding is of significance as multiple copies of IS431 are commonly present in the contexts of mecA, which might have the potential to form various composite transposons that could mediate the mobilization of mecA. This study also provides an explanation for the absence of ccr in some staphylococci isolates carrying mecA.

Analysis and Manipulation of Aspartate Pathway Genes for l-Lysine Overproduction from Methanol by Bacillus methanolicus▿

PubMed Central

Nærdal, Ingemar; Netzer, Roman; Ellingsen, Trond E.; Brautaset, Trygve

2011-01-01

We investigated the regulation and roles of six aspartate pathway genes in l-lysine overproduction in Bacillus methanolicus: dapG, encoding aspartokinase I (AKI); lysC, encoding AKII; yclM, encoding AKIII; asd, encoding aspartate semialdehyde dehydrogenase; dapA, encoding dihydrodipicolinate synthase; and lysA, encoding meso-diaminopimelate decarboxylase. Analysis of the wild-type strain revealed that in vivo lysC transcription was repressed 5-fold by l-lysine and induced 2-fold by dl-methionine added to the growth medium. Surprisingly, yclM transcription was repressed 5-fold by dl-methionine, while the dapG, asd, dapA, and lysA genes were not significantly repressed by any of the aspartate pathway amino acids. We show that the l-lysine-overproducing classical B. methanolicus mutant NOA2#13A52-8A66 has—in addition to a hom-1 mutation—chromosomal mutations in the dapG coding region and in the lysA promoter region. No mutations were found in its dapA, lysC, asd, and yclM genes. The mutant dapG gene product had abolished feedback inhibition by meso-diaminopimelate in vitro, and the lysA mutation was accompanied by an elevated (6-fold) lysA transcription level in vivo. Moreover, yclM transcription was increased 16-fold in mutant strain NOA2#13A52-8A66 compared to the wild-type strain. Overexpression of wild-type and mutant aspartate pathway genes demonstrated that all six genes are important for l-lysine overproduction as tested in shake flasks, and the effects were dependent on the genetic background tested. Coupled overexpression of up to three genes resulted in additive (above 80-fold) increased l-lysine production levels. PMID:21724876

Analysis and manipulation of aspartate pathway genes for L-lysine overproduction from methanol by Bacillus methanolicus.

PubMed

Nærdal, Ingemar; Netzer, Roman; Ellingsen, Trond E; Brautaset, Trygve

2011-09-01

We investigated the regulation and roles of six aspartate pathway genes in L-lysine overproduction in Bacillus methanolicus: dapG, encoding aspartokinase I (AKI); lysC, encoding AKII; yclM, encoding AKIII; asd, encoding aspartate semialdehyde dehydrogenase; dapA, encoding dihydrodipicolinate synthase; and lysA, encoding meso-diaminopimelate decarboxylase. Analysis of the wild-type strain revealed that in vivo lysC transcription was repressed 5-fold by L-lysine and induced 2-fold by dl-methionine added to the growth medium. Surprisingly, yclM transcription was repressed 5-fold by dl-methionine, while the dapG, asd, dapA, and lysA genes were not significantly repressed by any of the aspartate pathway amino acids. We show that the L-lysine-overproducing classical B. methanolicus mutant NOA2#13A52-8A66 has-in addition to a hom-1 mutation-chromosomal mutations in the dapG coding region and in the lysA promoter region. No mutations were found in its dapA, lysC, asd, and yclM genes. The mutant dapG gene product had abolished feedback inhibition by meso-diaminopimelate in vitro, and the lysA mutation was accompanied by an elevated (6-fold) lysA transcription level in vivo. Moreover, yclM transcription was increased 16-fold in mutant strain NOA2#13A52-8A66 compared to the wild-type strain. Overexpression of wild-type and mutant aspartate pathway genes demonstrated that all six genes are important for L-lysine overproduction as tested in shake flasks, and the effects were dependent on the genetic background tested. Coupled overexpression of up to three genes resulted in additive (above 80-fold) increased L-lysine production levels.

Ribosomal frameshifting and transcriptional slippage: From genetic steganography and cryptography to adventitious use

PubMed Central

Atkins, John F.; Loughran, Gary; Bhatt, Pramod R.; Firth, Andrew E.; Baranov, Pavel V.

2016-01-01

Genetic decoding is not ‘frozen’ as was earlier thought, but dynamic. One facet of this is frameshifting that often results in synthesis of a C-terminal region encoded by a new frame. Ribosomal frameshifting is utilized for the synthesis of additional products, for regulatory purposes and for translational ‘correction’ of problem or ‘savior’ indels. Utilization for synthesis of additional products occurs prominently in the decoding of mobile chromosomal element and viral genomes. One class of regulatory frameshifting of stable chromosomal genes governs cellular polyamine levels from yeasts to humans. In many cases of productively utilized frameshifting, the proportion of ribosomes that frameshift at a shift-prone site is enhanced by specific nascent peptide or mRNA context features. Such mRNA signals, which can be 5′ or 3′ of the shift site or both, can act by pairing with ribosomal RNA or as stem loops or pseudoknots even with one component being 4 kb 3′ from the shift site. Transcriptional realignment at slippage-prone sequences also generates productively utilized products encoded trans-frame with respect to the genomic sequence. This too can be enhanced by nucleic acid structure. Together with dynamic codon redefinition, frameshifting is one of the forms of recoding that enriches gene expression. PMID:27436286

Phytoplasma PMU1 exists as linear chromosomal and circular extrachromosomal elements and has enhanced expression in insect vectors compared with plant hosts.

PubMed

Toruño, Tania Y; Musić, Martina Seruga; Simi, Silvia; Nicolaisen, Mogens; Hogenhout, Saskia A

2010-09-01

Phytoplasmas replicate intracellularly in plants and insects and are dependent on both hosts for dissemination in nature. Phytoplasmas have small genomes lacking genes for major metabolic pathways. Nevertheless, their genomes harbour multicopy gene clusters that were named potential mobile units (PMUs). PMU1 is the largest most complete repeat among the PMUs in the genome of Aster Yellows phytoplasma strain Witches' Broom (AY-WB). PMU1 is c. 20 kb in size and contains 21 genes encoding DNA replication and predicted membrane-targeted proteins. Here we show that AY-WB has a chromosomal linear PMU1 (L-PMU1) and an extrachromosomal circular PMU1 (C-PMU1). The C-PMU1 copy number was consistently higher by in average approximately fivefold in insects compared with plants and PMU1 gene expression levels were also considerably higher in insects indicating that C-PMU1 synthesis and expression are regulated. We found that the majority of AY-WB virulence genes lie on chromosomal PMU regions that have similar gene content and organization as PMU1 providing evidence that PMUs contribute to phytoplasma host adaptation and have integrated into the AY-WB chromosome. © 2010 Blackwell Publishing Ltd.

Cloning and characterization of the Bacillus subtilis birA gene encoding a repressor of the biotin operon.

PubMed

Bower, S; Perkins, J; Yocum, R R; Serror, P; Sorokin, A; Rahaim, P; Howitt, C L; Prasad, N; Ehrlich, S D; Pero, J

1995-05-01

The Bacillus subtilis birA gene, which regulates biotin biosynthesis, has been cloned and characterized. The birA gene maps at 202 degrees on the B. subtilis chromosome and encodes a 36,200-Da protein that is 27% identical to Escherichia coli BirA protein. Three independent mutations in birA that lead to deregulation of biotin synthesis alter single amino acids in the amino-terminal end of the protein. The amino-terminal region that is affected by these three birA mutations shows sequence similarity to the helix-turn-helix DNA binding motif previously identified in E. coli BirA protein. B. subtilis BirA protein also possesses biotin-protein ligase activity, as judged by its ability to complement a conditional lethal birA mutant of E. coli.

Cloning and characterization of the Bacillus subtilis birA gene encoding a repressor of the biotin operon.

PubMed Central

Bower, S; Perkins, J; Yocum, R R; Serror, P; Sorokin, A; Rahaim, P; Howitt, C L; Prasad, N; Ehrlich, S D; Pero, J

1995-01-01

The Bacillus subtilis birA gene, which regulates biotin biosynthesis, has been cloned and characterized. The birA gene maps at 202 degrees on the B. subtilis chromosome and encodes a 36,200-Da protein that is 27% identical to Escherichia coli BirA protein. Three independent mutations in birA that lead to deregulation of biotin synthesis alter single amino acids in the amino-terminal end of the protein. The amino-terminal region that is affected by these three birA mutations shows sequence similarity to the helix-turn-helix DNA binding motif previously identified in E. coli BirA protein. B. subtilis BirA protein also possesses biotin-protein ligase activity, as judged by its ability to complement a conditional lethal birA mutant of E. coli. PMID:7730294

Expression of Duplicate msa Genes in the Salmonid Pathogen Renibacterium salmoninarum

PubMed Central

Rhodes, Linda D.; Coady, Alison M.; Strom, Mark S.

2002-01-01

Renibacterium salmoninarum is a gram-positive bacterium responsible for bacterial kidney disease of salmon and trout. R. salmoninarum has two identical copies of the gene encoding major soluble antigen (MSA), an immunodominant, extracellular protein. To determine whether one or both copies of msa are expressed, reporter plasmids encoding a fusion of MSA and green fluorescent protein controlled by 0.6 kb of promoter region from msa1 or msa2 were constructed and introduced into R. salmoninarum. Single copies of the reporter plasmids integrated into the chromosome by homologous recombination. Expression of mRNA and protein from the integrated plasmids was detected, and transformed cells were fluorescent, demonstrating that both msa1 and msa2 are expressed under in vitro conditions. This is the first report of successful transformation and homologous recombination in R. salmoninarum. PMID:12406741

Typing of Panton-Valentine Leukocidin-Encoding Phages and lukSF-PV Gene Sequence Variation in Staphylococcus aureus from China.

PubMed

Zhao, Huanqiang; Hu, Fupin; Jin, Shu; Xu, Xiaogang; Zou, Yuhan; Ding, Baixing; He, Chunyan; Gong, Fang; Liu, Qingzhong

2016-01-01

Panton-Valentine leukocidin (PVL, encoded by lukSF-PV genes), a bi-component and pore-forming toxin, is carried by different staphylococcal bacteriophages. The prevalence of PVL in Staphylococcus aureus has been reported around the globe. However, the data on PVL-encoding phage types, lukSF-PV gene variation and chromosomal phage insertion sites for PVL-positive S. aureus are limited, especially in China. In order to obtain a more complete understanding of the molecular epidemiology of PVL-positive S. aureus, an integrated and modified PCR-based scheme was applied to detect the PVL-encoding phage types. Phage insertion locus and the lukSF-PV variant were determined by PCR and sequencing. Meanwhile, the genetic background was characterized by staphylococcal cassette chromosome mec (SCCmec) typing, staphylococcal protein A (spa) gene polymorphisms typing, pulsed-field gel electrophoresis (PFGE) typing, accessory gene regulator (agr) locus typing and multilocus sequence typing (MLST). Seventy eight (78/1175, 6.6%) isolates possessed the lukSF-PV genes and 59.0% (46/78) of PVL-positive strains belonged to CC59 lineage. Eight known different PVL-encoding phage types were detected, and Φ7247PVL/ΦST5967PVL (n = 13) and ΦPVL (n = 12) were the most prevalent among them. While 25 (25/78, 32.1%) isolates, belonging to ST30, and ST59 clones, were unable to be typed by the modified PCR-based scheme. Single nucleotide polymorphisms (SNPs) were identified at five locations in the lukSF-PV genes, two of which were non-synonymous. Maximum-likelihood tree analysis of attachment sites sequences detected six SNP profiles for attR and eight for attL, respectively. In conclusion, the PVL-positive S. aureus mainly harbored Φ7247PVL/ΦST5967PVL and ΦPVL in the regions studied. lukSF-PV gene sequences, PVL-encoding phages, and phage insertion locus generally varied with lineages. Moreover, PVL-positive clones that have emerged worldwide likely carry distinct phages.

Fine mapping of Restorer-of-fertility in pepper (Capsicum annuum L.) identified a candidate gene encoding a pentatricopeptide repeat (PPR)-containing protein.

PubMed

Jo, Yeong Deuk; Ha, Yeaseong; Lee, Joung-Ho; Park, Minkyu; Bergsma, Alex C; Choi, Hong-Il; Goritschnig, Sandra; Kloosterman, Bjorn; van Dijk, Peter J; Choi, Doil; Kang, Byoung-Cheorl

2016-10-01

Using fine mapping techniques, the genomic region co-segregating with Restorer - of - fertility ( Rf ) in pepper was delimited to a region of 821 kb in length. A PPR gene in this region, CaPPR6 , was identified as a strong candidate for Rf based on expression pattern and characteristics of encoding sequence. Cytoplasmic-genic male sterility (CGMS) has been used for the efficient production of hybrid seeds in peppers (Capsicum annuum L.). Although the mitochondrial candidate genes that might be responsible for cytoplasmic male sterility (CMS) have been identified, the nuclear Restorer-of-fertility (Rf) gene has not been isolated. To identify the genomic region co-segregating with Rf in pepper, we performed fine mapping using an Rf-segregating population consisting of 1068 F2 individuals, based on BSA-AFLP and a comparative mapping approach. Through six cycles of chromosome walking, the co-segregating region harboring the Rf locus was delimited to be within 821 kb of sequence. Prediction of expressed genes in this region based on transcription analysis revealed four candidate genes. Among these, CaPPR6 encodes a pentatricopeptide repeat (PPR) protein with PPR motifs that are repeated 14 times. Characterization of the CaPPR6 protein sequence, based on alignment with other homologs, showed that CaPPR6 is a typical Rf-like (RFL) gene reported to have undergone diversifying selection during evolution. A marker developed from a sequence near CaPPR6 showed a higher prediction rate of the Rf phenotype than those of previously developed markers when applied to a panel of breeding lines of diverse origin. These results suggest that CaPPR6 is a strong candidate for the Rf gene in pepper.

A Novel Molecular Target for Breast Cancer Prevention and Treatment

DTIC Science & Technology

2004-06-01

Nor-i) fusion protein generated by the t(9;22) chromosomal translocation in extraskeletal myxoid chondrosarcoma is about 270-fold more active than...Bussieres, F. Courjal, and M. B. Goldring. 1999. The EWS/TEC fusion protein encoded by the t(9;22) chromosomal translocation in human chondrosarcomas is

Rye B chromosomes encode a functional Argonaute-like protein with in vitro slicer activities similar to its A chromosome paralog.

PubMed

Ma, Wei; Gabriel, Tobias Sebastian; Martis, Mihaela Maria; Gursinsky, Torsten; Schubert, Veit; Vrána, Jan; Doležel, Jaroslav; Grundlach, Heidrun; Altschmied, Lothar; Scholz, Uwe; Himmelbach, Axel; Behrens, Sven-Erik; Banaei-Moghaddam, Ali Mohammad; Houben, Andreas

2017-01-01

B chromosomes (Bs) are supernumerary, dispensable parts of the nuclear genome, which appear in many different species of eukaryote. So far, Bs have been considered to be genetically inert elements without any functional genes. Our comparative transcriptome analysis and the detection of active RNA polymerase II (RNAPII) in the proximity of B chromatin demonstrate that the Bs of rye (Secale cereale) contribute to the transcriptome. In total, 1954 and 1218 B-derived transcripts with an open reading frame were expressed in generative and vegetative tissues, respectively. In addition to B-derived transposable element transcripts, a high percentage of short transcripts without detectable similarity to known proteins and gene fragments from A chromosomes (As) were found, suggesting an ongoing gene erosion process. In vitro analysis of the A- and B-encoded AGO4B protein variants demonstrated that both possess RNA slicer activity. These data demonstrate unambiguously the presence of a functional AGO4B gene on Bs and that these Bs carry both functional protein coding genes and pseudogene copies. Thus, B-encoded genes may provide an additional level of gene control and complexity in combination with their related A-located genes. Hence, physiological effects, associated with the presence of Bs, may partly be explained by the activity of B-located (pseudo)genes. © 2016 IPK Gatersleben. New Phytologist © 2016 New Phytologist Trust.

Identification of new susceptibility loci for osteoarthritis (arcOGEN): a genome-wide association study.

PubMed

Zeggini, Eleftheria; Panoutsopoulou, Kalliope; Southam, Lorraine; Rayner, Nigel W; Day-Williams, Aaron G; Lopes, Margarida C; Boraska, Vesna; Esko, Tonu; Evangelou, Evangelos; Hoffman, Albert; Houwing-Duistermaat, Jeanine J; Ingvarsson, Thorvaldur; Jonsdottir, Ingileif; Jonnson, Helgi; Kerkhof, Hanneke J; Kloppenburg, Margreet; Bos, Steffan D; Mangino, Massimo; Metrustry, Sarah; Slagboom, P Eline; Thorleifsson, Gudmar; Raine, Emma V A; Ratnayake, Madhushika; Ricketts, Michelle; Beazley, Claude; Blackburn, Hannah; Bumpstead, Suzannah; Elliott, Katherine S; Hunt, Sarah E; Potter, Simon C; Shin, So-Youn; Yadav, Vijay K; Zhai, Guangju; Sherburn, Kate; Dixon, Kate; Arden, Elizabeth; Aslam, Nadim; Battley, Phillippa-kate; Carluke, Ian; Doherty, Sally; Gordon, Andrew; Joseph, John; Keen, Richard; Koller, Nicola C; Mitchell, Sheryl; O'Neill, Fiona; Paling, Ellen; Reed, Mike R; Rivadeneira, Fernando; Swift, Diane; Walker, Kirsten; Watkins, Bridget; Wheeler, Maggie; Birrell, Fraser; Ioannidis, John P A; Meulenbelt, Ingrid; Metspalu, Andres; Rai, Ashok; Salter, Donald; Stefansson, Kari; Stykarsdottir, Unnur; Uitterlinden, André G; van Meurs, Joyce B J; Chapman, Kay; Deloukas, Panos; Ollier, William E R; Wallis, Gillian A; Arden, Nigel; Carr, Andrew; Doherty, Michael; McCaskie, Andrew; Willkinson, J Mark; Ralston, Stuart H; Valdes, Ana M; Spector, Tim D; Loughlin, John

2012-09-01

Osteoarthritis is the most common form of arthritis worldwide and is a major cause of pain and disability in elderly people. The health economic burden of osteoarthritis is increasing commensurate with obesity prevalence and longevity. Osteoarthritis has a strong genetic component but the success of previous genetic studies has been restricted due to insufficient sample sizes and phenotype heterogeneity. We undertook a large genome-wide association study (GWAS) in 7410 unrelated and retrospectively and prospectively selected patients with severe osteoarthritis in the arcOGEN study, 80% of whom had undergone total joint replacement, and 11,009 unrelated controls from the UK. We replicated the most promising signals in an independent set of up to 7473 cases and 42,938 controls, from studies in Iceland, Estonia, the Netherlands, and the UK. All patients and controls were of European descent. We identified five genome-wide significant loci (binomial test p≤5·0×10(-8)) for association with osteoarthritis and three loci just below this threshold. The strongest association was on chromosome 3 with rs6976 (odds ratio 1·12 [95% CI 1·08-1·16]; p=7·24×10(-11)), which is in perfect linkage disequilibrium with rs11177. This SNP encodes a missense polymorphism within the nucleostemin-encoding gene GNL3. Levels of nucleostemin were raised in chondrocytes from patients with osteoarthritis in functional studies. Other significant loci were on chromosome 9 close to ASTN2, chromosome 6 between FILIP1 and SENP6, chromosome 12 close to KLHDC5 and PTHLH, and in another region of chromosome 12 close to CHST11. One of the signals close to genome-wide significance was within the FTO gene, which is involved in regulation of bodyweight-a strong risk factor for osteoarthritis. All risk variants were common in frequency and exerted small effects. Our findings provide insight into the genetics of arthritis and identify new pathways that might be amenable to future therapeutic intervention. arcOGEN was funded by a special purpose grant from Arthritis Research UK. Copyright © 2012 Elsevier Ltd. All rights reserved.

A comparative gene analysis with rice identified orthologous group II HKT genes and their association with Na(+) concentration in bread wheat.

PubMed

Ariyarathna, H A Chandima K; Oldach, Klaus H; Francki, Michael G

2016-01-19

Although the HKT transporter genes ascertain some of the key determinants of crop salt tolerance mechanisms, the diversity and functional role of group II HKT genes are not clearly understood in bread wheat. The advanced knowledge on rice HKT and whole genome sequence was, therefore, used in comparative gene analysis to identify orthologous wheat group II HKT genes and their role in trait variation under different saline environments. The four group II HKTs in rice identified two orthologous gene families from bread wheat, including the known TaHKT2;1 gene family and a new distinctly different gene family designated as TaHKT2;2. A single copy of TaHKT2;2 was found on each homeologous chromosome arm 7AL, 7BL and 7DL and each gene was expressed in leaf blade, sheath and root tissues under non-stressed and at 200 mM salt stressed conditions. The proteins encoded by genes of the TaHKT2;2 family revealed more than 93% amino acid sequence identity but ≤52% amino acid identity compared to the proteins encoded by TaHKT2;1 family. Specifically, variations in known critical domains predicted functional differences between the two protein families. Similar to orthologous rice genes on chromosome 6L, TaHKT2;1 and TaHKT2;2 genes were located approximately 3 kb apart on wheat chromosomes 7AL, 7BL and 7DL, forming a static syntenic block in the two species. The chromosomal region on 7AL containing TaHKT2;1 7AL-1 co-located with QTL for shoot Na(+) concentration and yield in some saline environments. The differences in copy number, genes sequences and encoded proteins between TaHKT2;2 homeologous genes and other group II HKT gene families within and across species likely reflect functional diversity for ion selectivity and transport in plants. Evidence indicated that neither TaHKT2;2 nor TaHKT2;1 were associated with primary root Na(+) uptake but TaHKT2;1 may be associated with trait variation for Na(+) exclusion and yield in some but not all saline environments.

Protection of CpG islands from DNA methylation is DNA-encoded and evolutionarily conserved.

PubMed

Long, Hannah K; King, Hamish W; Patient, Roger K; Odom, Duncan T; Klose, Robert J

2016-08-19

DNA methylation is a repressive epigenetic modification that covers vertebrate genomes. Regions known as CpG islands (CGIs), which are refractory to DNA methylation, are often associated with gene promoters and play central roles in gene regulation. Yet how CGIs in their normal genomic context evade the DNA methylation machinery and whether these mechanisms are evolutionarily conserved remains enigmatic. To address these fundamental questions we exploited a transchromosomic animal model and genomic approaches to understand how the hypomethylated state is formed in vivo and to discover whether mechanisms governing CGI formation are evolutionarily conserved. Strikingly, insertion of a human chromosome into mouse revealed that promoter-associated CGIs are refractory to DNA methylation regardless of host species, demonstrating that DNA sequence plays a central role in specifying the hypomethylated state through evolutionarily conserved mechanisms. In contrast, elements distal to gene promoters exhibited more variable methylation between host species, uncovering a widespread dependence on nucleotide frequency and occupancy of DNA-binding transcription factors in shaping the DNA methylation landscape away from gene promoters. This was exemplified by young CpG rich lineage-restricted repeat sequences that evaded DNA methylation in the absence of co-evolved mechanisms targeting methylation to these sequences, and species specific DNA binding events that protected against DNA methylation in CpG poor regions. Finally, transplantation of mouse chromosomal fragments into the evolutionarily distant zebrafish uncovered the existence of a mechanistically conserved and DNA-encoded logic which shapes CGI formation across vertebrate species. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

A chromosome-centric human proteome project (C-HPP) to characterize the sets of proteins encoded in chromosome 17.

PubMed

Liu, Suli; Im, Hogune; Bairoch, Amos; Cristofanilli, Massimo; Chen, Rui; Deutsch, Eric W; Dalton, Stephen; Fenyo, David; Fanayan, Susan; Gates, Chris; Gaudet, Pascale; Hincapie, Marina; Hanash, Samir; Kim, Hoguen; Jeong, Seul-Ki; Lundberg, Emma; Mias, George; Menon, Rajasree; Mu, Zhaomei; Nice, Edouard; Paik, Young-Ki; Uhlen, Mathias; Wells, Lance; Wu, Shiaw-Lin; Yan, Fangfei; Zhang, Fan; Zhang, Yue; Snyder, Michael; Omenn, Gilbert S; Beavis, Ronald C; Hancock, William S

2013-01-04

We report progress assembling the parts list for chromosome 17 and illustrate the various processes that we have developed to integrate available data from diverse genomic and proteomic knowledge bases. As primary resources, we have used GPMDB, neXtProt, PeptideAtlas, Human Protein Atlas (HPA), and GeneCards. All sites share the common resource of Ensembl for the genome modeling information. We have defined the chromosome 17 parts list with the following information: 1169 protein-coding genes, the numbers of proteins confidently identified by various experimental approaches as documented in GPMDB, neXtProt, PeptideAtlas, and HPA, examples of typical data sets obtained by RNASeq and proteomic studies of epithelial derived tumor cell lines (disease proteome) and a normal proteome (peripheral mononuclear cells), reported evidence of post-translational modifications, and examples of alternative splice variants (ASVs). We have constructed a list of the 59 "missing" proteins as well as 201 proteins that have inconclusive mass spectrometric (MS) identifications. In this report we have defined a process to establish a baseline for the incorporation of new evidence on protein identification and characterization as well as related information from transcriptome analyses. This initial list of "missing" proteins that will guide the selection of appropriate samples for discovery studies as well as antibody reagents. Also we have illustrated the significant diversity of protein variants (including post-translational modifications, PTMs) using regions on chromosome 17 that contain important oncogenes. We emphasize the need for mandated deposition of proteomics data in public databases, the further development of improved PTM, ASV, and single nucleotide variant (SNV) databases, and the construction of Web sites that can integrate and regularly update such information. In addition, we describe the distribution of both clustered and scattered sets of protein families on the chromosome. Since chromosome 17 is rich in cancer-associated genes, we have focused the clustering of cancer-associated genes in such genomic regions and have used the ERBB2 amplicon as an example of the value of a proteogenomic approach in which one integrates transcriptomic with proteomic information and captures evidence of coexpression through coordinated regulation.

Measuring the spectrum of mutation induced by nitrogen ions and protons in the human-hamster hybrid cell line A(L)C

NASA Technical Reports Server (NTRS)

Kraemer, S. M.; Kronenberg, A.; Ueno, A.; Waldren, C. A.; Chatterjee, A. (Principal Investigator)

2000-01-01

Astronauts can be exposed to charged particles, including protons, alpha particles and heavier ions, during space flights. Therefore, studying the biological effectiveness of these sparsely and densely ionizing radiations is important to understanding the potential health effects for astronauts. We evaluated the mutagenic effectiveness of sparsely ionizing 55 MeV protons and densely ionizing 32 MeV/nucleon nitrogen ions using cells of two human-hamster cell lines, A(L) and A(L)C. We have previously characterized a spectrum of mutations, including megabase deletions, in human chromosome 11, the sole human chromosome in the human-hamster hybrid cell lines A(L)C and A(L). CD59(-) mutants have lost expression of a human cell surface antigen encoded by the CD59 gene located at 11p13. Deletion of genes located on the tip of the short arm of 11 (11p15.5) is lethal to the A(L) hybrid, so that CD59 mutants that lose the entire chromosome 11 die and escape detection. In contrast, deletion of the 11p15.5 region is not lethal in the hybrid A(L)C, allowing for the detection of chromosome loss or other chromosomal mutations involving 11p15.5. The 55 MeV protons and 32 MeV/nucleon nitrogen ions were each about 10 times more mutagenic per unit dose at the CD59 locus in A(L)C cells than in A(L) cells. In the case of nitrogen ions, the mutations observed in A(L)C cells were predominantly due to chromosome loss events or 11p deletions, often containing a breakpoint in the pericentromeric region. The increase in the CD59(-) mutant fraction for A(L)C cells exposed to protons was associated with either translocation of portions of 11q onto a hamster chromosome, or discontinuous or "skipping" mutations. We demonstrate here that A(L)C cells are a powerful tool that will aid in the understanding of the mutagenic effects of different types of ionizing radiation.

The molecular architecture of human N-acetylgalactosamine kinase.

PubMed

Thoden, James B; Holden, Hazel M

2005-09-23

Galactokinase plays a key role in normal galactose metabolism by catalyzing the conversion of alpha-d-galactose to galactose 1-phosphate. Within recent years, the three-dimensional structures of human galactokinase and two bacterial forms of the enzyme have been determined. Originally, the gene encoding galactokinase in humans was mapped to chromosome 17. An additional gene, encoding a protein with sequence similarity to galactokinase, was subsequently mapped to chromosome 15. Recent reports have shown that this second gene (GALK2) encodes an enzyme with greater activity against GalNAc than galactose. This enzyme, GalNAc kinase, has been implicated in a salvage pathway for the reutilization of free GalNAc derived from the degradation of complex carbohydrates. Here we report the first structural analysis of a GalNAc kinase. The structure of the human enzyme was solved in the presence of MnAMPPNP and GalNAc or MgATP and GalNAc (which resulted in bound products in the active site). The enzyme displays a distinctly bilobal appearance with its active site wedged between the two domains. The N-terminal region is dominated by a seven-stranded mixed beta-sheet, whereas the C-terminal motif contains two layers of anti-parallel beta-sheet. The overall topology displayed by GalNAc kinase places it into the GHMP superfamily of enzymes, which generally function as small molecule kinases. From this investigation, the geometry of the GalNAc kinase active site before and after catalysis has been revealed, and the determinants of substrate specificity have been defined on a molecular level.

Remarkably Divergent Regions Punctuate the Genome Assembly of the Caenorhabditis elegans Hawaiian Strain CB4856

PubMed Central

Thompson, Owen A.; Snoek, L. Basten; Nijveen, Harm; Sterken, Mark G.; Volkers, Rita J. M.; Brenchley, Rachel; van’t Hof, Arjen; Bevers, Roel P. J.; Cossins, Andrew R.; Yanai, Itai; Hajnal, Alex; Schmid, Tobias; Perkins, Jaryn D.; Spencer, David; Kruglyak, Leonid; Andersen, Erik C.; Moerman, Donald G.; Hillier, LaDeana W.; Kammenga, Jan E.; Waterston, Robert H.

2015-01-01

The Hawaiian strain (CB4856) of Caenorhabditis elegans is one of the most divergent from the canonical laboratory strain N2 and has been widely used in developmental, population, and evolutionary studies. To enhance the utility of the strain, we have generated a draft sequence of the CB4856 genome, exploiting a variety of resources and strategies. When compared against the N2 reference, the CB4856 genome has 327,050 single nucleotide variants (SNVs) and 79,529 insertion–deletion events that result in a total of 3.3 Mb of N2 sequence missing from CB4856 and 1.4 Mb of sequence present in CB4856 but not present in N2. As previously reported, the density of SNVs varies along the chromosomes, with the arms of chromosomes showing greater average variation than the centers. In addition, we find 61 regions totaling 2.8 Mb, distributed across all six chromosomes, which have a greatly elevated SNV density, ranging from 2 to 16% SNVs. A survey of other wild isolates show that the two alternative haplotypes for each region are widely distributed, suggesting they have been maintained by balancing selection over long evolutionary times. These divergent regions contain an abundance of genes from large rapidly evolving families encoding F-box, MATH, BATH, seven-transmembrane G-coupled receptors, and nuclear hormone receptors, suggesting that they provide selective advantages in natural environments. The draft sequence makes available a comprehensive catalog of sequence differences between the CB4856 and N2 strains that will facilitate the molecular dissection of their phenotypic differences. Our work also emphasizes the importance of going beyond simple alignment of reads to a reference genome when assessing differences between genomes. PMID:25995208

The phosphotransferase system-dependent sucrose utilization regulon in enteropathogenic Escherichia coli strains is located in a variable chromosomal region containing iap sequences.

PubMed

Treviño-Quintanilla, Luis Gerardo; Escalante, Adelfo; Caro, Alma Delia; Martínez, Alfredo; González, Ricardo; Puente, José Luis; Bolívar, Francisco; Gosset, Guillermo

2007-01-01

The capacity to utilize sucrose as a carbon and energy source (Scr(+) phenotype) is a highly variable trait among Escherichia coli strains. In this study, seven enteropathogenic E. coli (EPEC) strains from different sources were studied for their capacity to grow using sucrose. Liquid media cultures showed that all analyzed strains have the Scr(+) phenotype and two distinct groups were defined: one of five and another of two strains displaying doubling times of 67 and 125 min, respectively. The genes conferring the Scr(+) phenotype in one of the fast-growing strains (T19) were cloned and sequenced. Comparative sequence analysis revealed that this strain possesses the scr regulon genes scrKYABR, encoding phosphoenolpyruvate:phosphotransferase system-dependent sucrose transport and utilization activities. Transcript level quantification revealed sucrose-dependent induction of scrK and scrR genes in fast-growing strains, whereas no transcripts were detected in slow-growing strains. Sequence comparison analysis revealed that the scr genes in strain T19 are almost identical to those present in the scr regulon of prototype EPEC E2348/69 and in both strains, the scr genes are inserted in the chromosomal intergenic region of hypothetical genes ygcE and ygcF. Comparison of the ygcE-ygcF intergenic region sequence of strains MG1655, enterohemorrhagic EDL933, uropathogenic ECFT073 and EPEC T19-E2348/69 revealed that the number of extragenic highly repeated iap sequences corresponded to nine, four, two and none, respectively. These results show that the iap sequence-containing chromosomal ygcE-ygcF intergenic region is highly variable in E. coli. Copyright (c) 2007 S. Karger AG, Basel.

ParC subunit of DNA topoisomerase IV of Streptococcus pneumoniae is a primary target of fluoroquinolones and cooperates with DNA gyrase A subunit in forming resistance phenotype.

PubMed Central

Muñoz, R; De La Campa, A G

1996-01-01

The genes encoding the ParC and ParE subunits of topoisomerase IV of Streptococcus pneumoniae, together with the region encoding amino acids 46 to 172 (residue numbers are as in Escherichia coli) of the pneumococcal GyrA subunit, were partially characterized. The gyrA gene maps to a physical location distant from the gyrB and parC loci on the chromosome, whereas parC is closely linked to parE. Ciprofloxacin-resistant (Cpr) clinical isolates of S. pneumoniae had mutations affecting amino acid residues of the quinolone resistance-determining region of ParC (low-level Cpr) or in both quinolone resistance-determining regions of ParC and GyrA (high-level Cpr). Mutations were found in residue positions equivalent to the serine at position 83 and the aspartic acid at position 87 of the E. coli GyrA subunit. Transformation experiments suggest that ParC is the primary target of ciprofloxacin. Mutation in parC appears to be a prerequisite before mutations in gyrA can influence resistance levels. PMID:8891124

Developmental rearrangement of cyanobacterial nif genes: nucleotide sequence, open reading frames, and cytochrome P-450 homology of the Anabaena sp. strain PCC 7120 nifD element.

PubMed Central

Lammers, P J; McLaughlin, S; Papin, S; Trujillo-Provencio, C; Ryncarz, A J

1990-01-01

An 11-kbp DNA element of unknown function interrupts the nifD gene in vegetative cells of Anabaena sp. strain PCC 7120. In developing heterocysts the nifD element excises from the chromosome via site-specific recombination between short repeat sequences that flank the element. The nucleotide sequence of the nifH-proximal half of the element was determined to elucidate the genetic potential of the element. Four open reading frames with the same relative orientation as the nifD element-encoded xisA gene were identified in the sequenced region. Each of the open reading frames was preceded by a reasonable ribosome-binding site and had biased codon utilization preferences consistent with low levels of expression. Open reading frame 3 was highly homologous with three cytochrome P-450 omega-hydroxylase proteins and showed regional homology to functionally significant domains common to the cytochrome P-450 superfamily. The sequence encoding open reading frame 2 was the most highly conserved portion of the sequenced region based on heterologous hybridization experiments with three genera of heterocystous cyanobacteria. Images PMID:2123860

Guardian small RNAs and sex determination.

PubMed

Katsuma, Susumu; Kawamoto, Munetaka; Kiuchi, Takashi

2014-01-01

The W chromosome of the silkworm Bombyx mori has been known to determine femaleness for more than 80 years. However, the feminizing gene has not been molecularly identified, because the B. mori W chromosome is almost fully occupied by a large number of transposable elements. The W chromosome-derived feminizing factor of B. mori was recently shown to be a female-specific PIWI-interacting RNA (piRNA). piRNAs are small RNAs that potentially repress invading "non-self" elements (e.g., transposons and virus-like elements) by associating with PIWI proteins. Our results revealed that female-specific piRNA precursors, which we named Fem, are transcribed from the sex-determining region of the W chromosome at the early embryonic stage and are processed into a single mature piRNA (Fem piRNA). Fem piRNA forms a complex with Siwi (silkworm Piwi), which cleaves a protein-coding mRNA transcribed from the Z chromosome. RNA interference of this Z-linked gene, which we named Masc, revealed that this gene encodes a protein required for masculinization and dosage compensation. Fem and Masc both participate in the ping-pong cycle of the piRNA amplification loop by associating with the 2 B. mori PIWI proteins Siwi and BmAgo3 (silkworm Ago3), respectively, indicating that the piRNA-mediated interaction between the 2 sex chromosomes is the primary signal for the B. mori sex determination cascade. Fem is a non-transposable repetitive sequence on the W chromosome, whereas Masc is a single-copy protein-coding gene. It is of great interest how the piRNA system recognizes "self "Masc mRNA as "non-self" RNA.

Assignment of the gene encoding the 5-HT{sub 1E} serotonin receptor (S31) (locus HTR1E) to human chromosome 6q14-q15

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

Levy, F.O.; Tasken, K.; Solberg, R.

1994-08-01

The human gene for the 5-HT{sub 1E} serotonin receptor was recently cloned, but no chromosomal assignment has yet been given to this gene (locus HTR1E). In this work, we demonstrate by two independent polymerase chain reactions on a panel of human-hamster somatic cell hybrid genomic DNA that the 5-HT{sub 1E} serotonin receptor gene is localized on human chromosome 6. Furthermore, by means of in situ hybridization to human metaphase chromosomes, using the cloned 5-HT{sub 1E} receptor gene (phage clone {lambda}-S31) as a probe, we demonstrate that this gene is localized to the q14-q15 region on chromosome 6. Screening of genomicmore » DNA from 15 unrelated Caucasian individuals, using as a probe the open reading frame of the cloned 5-HT{sub 1E} receptor gene, did not reveal any restriction fragment length polymorphisms with the enzymes BamHI, BanII, BglII, EcoRI, HincII, HindIII, HinfI, MspI, PstI, and PvuII. Since the 5-HT{sub 1E} receptor is found mainly in the cerebral cortex and abnormal function of the serotonergic system has been implicated in a variety of neurologic and psychiatric diseases, the precise chromosomal assignment of the 5-HT{sub 1E} receptor gene is the crucial first step toward the evaluation of this locus as a candidate for mutations in such syndromes. 28 refs., 2 figs., 2 tabs.« less

Zygote arrest 1 (Zar1) is an evolutionarily conserved gene expressed in vertebrate ovaries.

PubMed

Wu, Xuemei; Wang, Pei; Brown, Christopher A; Zilinski, Carolyn A; Matzuk, Martin M

2003-09-01

Zygote arrest 1 (ZAR1) is an ovary-specific maternal factor that plays essential roles during the oocyte-to-embryo transition. In mice, the Zar1 mRNA is detected as a 1.4-kilobase (kb) transcript that is synthesized exclusively in growing oocytes. To further understand the functions of ZAR1, we have cloned the orthologous Zar1 cDNA and/or genes for mouse, rat, human, frog, zebrafish, and pufferfish. The entire mouse Zar1 gene and a related pseudogene span approximately 4.0 kb, contain four exons, and map to adjacent loci on mouse chromosome 5. The human ZAR1 orthologous gene similarly consists of four exons and resides on human chromosome 4p12, which is syntenic with the mouse Zar1 chromosomal locus. Rat (Rattus norvegicus) and pufferfish (Fugu rubripes) Zar1 genes were recognized by database mining and deduced protein alignment analysis. The rat Zar1 gene also maps to a region that is syntenic with the mouse Zar1 gene locus on rat chromosome 14. Frog (Xenopus laevis) and zebrafish (Danio rerio) Zar1 orthologs were cloned by reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends analysis of ovarian mRNA. Unlike mouse and human, the frog Zar1 is detected in multiple tissues, including lung, muscle, and ovary. The Zar1 mRNA appears in the cytoplasm of oocytes and persists until the tailbud stage during frog embryogenesis. Mouse, rat, human, frog, zebrafish, and pufferfish Zar1 genes encode proteins of 361, 361, 424, 295, 329, and 320 amino acids, respectively, and share 50.8%-88.1% amino acid identity. Regions of the N-termini of these ZAR1 orthologs show high sequence identity among these various proteins. However, the C-terminal 103 amino acids of these proteins, encoded by exons 2-4, contain an atypical eight-cysteine Plant Homeo Domain motif and are highly conserved, sharing 80.6%-98.1% identity among these species. These findings suggest that the carboxyl-termini of these ZAR1 proteins contain an important functional domain that is conserved through vertebrate evolution and that may be necessary for normal female reproduction in the transition from oocyte to embryonic life.

Pod Corn Is Caused by Rearrangement at the Tunicate1 Locus[W][OA

PubMed Central

Han, Jong-Jin; Jackson, David; Martienssen, Robert

2012-01-01

Pod corn (Zea mays var tunicata) was once regarded as ancestral to cultivated maize, and was prized by pre-Columbian cultures for its magical properties. Tunicate1 (Tu1) is a dominant pod corn mutation in which kernels are completely enclosed in leaflike glumes. Here we show that Tu1 encodes a MADS box transcription factor expressed in leaves whose 5′ regulatory region is fused by a 1.8-Mb chromosomal inversion to the 3′ region of a gene expressed in the inflorescence. Both genes are further duplicated, accounting for classical derivative alleles isolated by recombination, and Tu1 transgenes interact with these derivative alleles in a dose-dependent manner. In young ear primordia, TU1 proteins are nuclearly localized in specific cells at the base of spikelet pair meristems. Tu1 branch determination defects resemble those in ramosa mutants, which encode regulatory proteins expressed in these same cells, accounting for synergism in double mutants discovered almost 100 years ago. The Tu1 rearrangement is not found in ancestral teosinte and arose after domestication of maize. PMID:22829149

The mapping of the human 52-kD Ro/SSA autoantigen gene to human chromosome II, and its polymorphisms

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

Frank, M.B.; Itoh, Kazuko; Fujisaku, Atsushi

1993-01-01

Autoantibodies to the ribonucleoprotein Ro/SSA occur in nearly half of the patients with systemic lupus erythematosus and are associated with lymphopenia, photosensitive dermatitis, and pulmonary and renal disease, which suggests that they have an immunopathologic role. The majority of Ro/SSA precipitin-positive patients produce serum antibodies that bind to the 60-kD and 52-kD Ro/SSA proteins. The authors previously isolated and determined the nucleotide sequence of a cDNA clone that encodes the 52-kD form of the human Ro/SSA protein. In the present study, they have determined the chromosomal location of the gene by in situ hybridization to the end of the shortmore » arm of chromosome 11. Hybridization of portions of the cDNA probe to restriction enzyme-digested DNA indicated the gene is composed of at least three exons. The exon encoding the putative zinc fingers of this protein was found to be distinct from that which encodes the leucine zipper. An RFLP of this gene was identified and is associated with the presence of lupus, primarily in black Americans. 60 refs., 3 figs., 3 tabs.« less

Characterization of a new multigene family encoding isomaltases in the yeast Saccharomyces cerevisiae, the IMA family.

PubMed

Teste, Marie-Ange; François, Jean Marie; Parrou, Jean-Luc

2010-08-27

It has been known for a long time that the yeast Saccharomyces cerevisiae can assimilate alpha-methylglucopyranoside and isomaltose. We here report the identification of 5 genes (YGR287c, YIL172c, YJL216c, YJL221c and YOL157c), which, similar to the SUCx, MALx, or HXTx multigene families, are located in the subtelomeric regions of different chromosomes. They share high nucleotide sequence identities between themselves (66-100%) and with the MALx2 genes (63-74%). Comparison of their amino acid sequences underlined a substitution of threonine by valine in region II, one of the four highly conserved regions of the alpha-glucosidase family. This change was previously shown to be sufficient to discriminate alpha-1,4- to alpha-1,6-glucosidase activity in YGR287c (Yamamoto, K., Nakayama, A., Yamamoto, Y., and Tabata, S. (2004) Eur. J. Biochem. 271, 3414-3420). We showed that each of these five genes encodes a protein with alpha-glucosidase activity on isomaltose, and we therefore renamed these genes IMA1 to IMA5 for IsoMAltase. Our results also illustrated that sequence polymorphisms among this family led to interesting variability of gene expression patterns and of catalytic efficiencies on different substrates, which altogether should account for the absence of functional redundancy for growth on isomaltose. Indeed, deletion studies revealed that IMA1/YGR287c encodes the major isomaltase and that growth on isomaltose required the presence of AGT1, which encodes an alpha-glucoside transporter. Expressions of IMA1 and IMA5/YJL216c were strongly induced by maltose, isomaltose, and alpha-methylglucopyranoside, in accordance with their regulation by the Malx3p-transcription system. The physiological relevance of this IMAx multigene family in S. cerevisiae is discussed.

CsrA Represses Translation of sdiA, Which Encodes the N-Acylhomoserine-l-Lactone Receptor of Escherichia coli, by Binding Exclusively within the Coding Region of sdiA mRNA ▿ †

PubMed Central

Yakhnin, Helen; Baker, Carol S.; Berezin, Igor; Evangelista, Michael A.; Rassin, Alisa; Romeo, Tony; Babitzke, Paul

2011-01-01

The RNA binding protein CsrA is the central component of a conserved global regulatory system that activates or represses gene expression posttranscriptionally. In every known example of CsrA-mediated translational control, CsrA binds to the 5′ untranslated region of target transcripts, thereby repressing translation initiation and/or altering the stability of the RNA. Furthermore, with few exceptions, repression by CsrA involves binding directly to the Shine-Dalgarno sequence and blocking ribosome binding. sdiA encodes the quorum-sensing receptor for N-acyl-l-homoserine lactone in Escherichia coli. Because sdiA indirectly stimulates transcription of csrB, which encodes a small RNA (sRNA) antagonist of CsrA, we further explored the relationship between sdiA and the Csr system. Primer extension analysis revealed four putative transcription start sites within 85 nucleotides of the sdiA initiation codon. Potential σ70-dependent promoters were identified for each of these primer extension products. In addition, two CsrA binding sites were predicted in the initially translated region of sdiA. Expression of chromosomally integrated sdiA′-′lacZ translational fusions containing the entire promoter and CsrA binding site regions indicates that CsrA represses sdiA expression. The results from gel shift and footprint studies demonstrate that tight binding of CsrA requires both of these sites. Furthermore, the results from toeprint and in vitro translation experiments indicate that CsrA represses translation of sdiA by directly competing with 30S ribosomal subunit binding. Thus, this represents the first example of CsrA preventing translation by interacting solely within the coding region of an mRNA target. PMID:21908661

GTF2IRD2 is located in the Williams–Beuren syndrome critical region 7q11.23 and encodes a protein with two TFII-I-like helix–loop–helix repeats

PubMed Central

Makeyev, Aleksandr V.; Erdenechimeg, Lkhamsuren; Mungunsukh, Ognoon; Roth, Jutta J.; Enkhmandakh, Badam; Ruddle, Frank H.; Bayarsaihan, Dashzeveg

2004-01-01

Williams–Beuren syndrome (also known as Williams syndrome) is caused by a deletion of a 1.55- to 1.84-megabase region from chromosome band 7q11.23. GTF2IRD1 and GTF2I, located within this critical region, encode proteins of the TFII-I family with multiple helix–loop–helix domains known as I repeats. In the present work, we characterize a third member, GTF2IRD2, which has sequence and structural similarity to the GTF2I and GTF2IRD1 paralogs. The ORF encodes a protein with several features characteristic of regulatory factors, including two I repeats, two leucine zippers, and a single Cys-2/His-2 zinc finger. The genomic organization of human, baboon, rat, and mouse genes is well conserved. Our exon-by-exon comparison has revealed that GTF2IRD2 is more closely related to GTF2I than to GTF2IRD1 and apparently is derived from the GTF2I sequence. The comparison of GTF2I and GTF2IRD2 genes revealed two distinct regions of homology, indicating that the helix–loop–helix domain structure of the GTF2IRD2 gene has been generated by two independent genomic duplications. We speculate that GTF2I is derived from GTF2IRD1 as a result of local duplication and the further evolution of its structure was associated with its functional specialization. Comparison of genomic sequences surrounding GTF2IRD2 genes in mice and humans allows refinement of the centromeric breakpoint position of the primate-specific inversion within the Williams–Beuren syndrome critical region. PMID:15243160

GTF2IRD2 is located in the Williams-Beuren syndrome critical region 7q11.23 and encodes a protein with two TFII-I-like helix-loop-helix repeats.

PubMed

Makeyev, Aleksandr V; Erdenechimeg, Lkhamsuren; Mungunsukh, Ognoon; Roth, Jutta J; Enkhmandakh, Badam; Ruddle, Frank H; Bayarsaihan, Dashzeveg

2004-07-27

Williams-Beuren syndrome (also known as Williams syndrome) is caused by a deletion of a 1.55- to 1.84-megabase region from chromosome band 7q11.23. GTF2IRD1 and GTF2I, located within this critical region, encode proteins of the TFII-I family with multiple helix-loop-helix domains known as I repeats. In the present work, we characterize a third member, GTF2IRD2, which has sequence and structural similarity to the GTF2I and GTF2IRD1 paralogs. The ORF encodes a protein with several features characteristic of regulatory factors, including two I repeats, two leucine zippers, and a single Cys-2/His-2 zinc finger. The genomic organization of human, baboon, rat, and mouse genes is well conserved. Our exon-by-exon comparison has revealed that GTF2IRD2 is more closely related to GTF2I than to GTF2IRD1 and apparently is derived from the GTF2I sequence. The comparison of GTF2I and GTF2IRD2 genes revealed two distinct regions of homology, indicating that the helix-loop-helix domain structure of the GTF2IRD2 gene has been generated by two independent genomic duplications. We speculate that GTF2I is derived from GTF2IRD1 as a result of local duplication and the further evolution of its structure was associated with its functional specialization. Comparison of genomic sequences surrounding GTF2IRD2 genes in mice and humans allows refinement of the centromeric breakpoint position of the primate-specific inversion within the Williams-Beuren syndrome critical region.

Maternally Expressed Gene 3, an imprinted non-coding RNA gene, is associated with meningioma pathogenesis and progression

PubMed Central

Zhang, Xun; Gejman, Roger; Mahta, Ali; Zhong, Ying; Rice, Kimberley A.; Zhou, Yunli; Cheunsuchon, Pornsuk; Louis, David N.; Klibanski, Anne

2010-01-01

Meningiomas are common tumors, representing 15-25% of all central nervous system tumors. NF2 gene inactivation on chromosome 22 has been shown as an early event in tumorigenesis; however, few factors underlying tumor growth and progression have been identified. Chromosomal abnormalities of 14q32 are often associated with meningioma pathogenesis and progression; therefore it has been proposed that an as yet unidentified tumor suppressor is present at this locus. MEG3 is an imprinted gene located at 14q32 that encodes a non-coding RNA with an anti-proliferative function. We found that MEG3 mRNA is highly expressed in normal arachnoidal cells. However, MEG3 is not expressed in the majority of human meningiomas or the human meningioma cell lines IOMM-Lee and CH157-MN. There is a strong association between loss of MEG3 expression and tumor grade. Allelic loss at the MEG3 locus is also observed in meningiomas, with increasing prevalence in higher grade tumors. In addition, there is an increase in CpG methylation within the promoter and the imprinting control region of MEG3 gene in meningiomas. Functionally, MEG3 suppresses DNA synthesis in both IOMM-Lee and CH157-MN cells by approximately 60% in BrdU incorporation assays. Colony-forming efficiency assays show that MEG3 inhibits colony formation in CH157-MN cells by approximately 80%. Furthermore, MEG3 stimulates p53-mediated transactivation in these cell lines. Therefore, these data are consistent with the hypothesis that MEG3, which encodes a non-coding RNA, may be a tumor suppressor gene at chromosome 14q32 involved in meningioma progression via a novel mechanism. PMID:20179190

Maternally expressed gene 3, an imprinted noncoding RNA gene, is associated with meningioma pathogenesis and progression.

PubMed

Zhang, Xun; Gejman, Roger; Mahta, Ali; Zhong, Ying; Rice, Kimberley A; Zhou, Yunli; Cheunsuchon, Pornsuk; Louis, David N; Klibanski, Anne

2010-03-15

Meningiomas are common tumors, representing 15% to 25% of all central nervous system tumors. NF2 gene inactivation on chromosome 22 has been shown as an early event in tumorigenesis; however, few factors underlying tumor growth and progression have been identified. The chromosomal abnormalities of 14q32 are often associated with meningioma pathogenesis and progression; therefore, it has been proposed that an as yet unidentified tumor suppressor is present at this locus. Maternally expressed gene 3 (MEG3) is an imprinted gene located at 14q32 which encodes a noncoding RNA with an antiproliferative function. We found that MEG3 mRNA is highly expressed in normal arachnoidal cells. However, MEG3 is not expressed in the majority of human meningiomas or the human meningioma cell lines IOMM-Lee and CH157-MN. There is a strong association between loss of MEG3 expression and tumor grade. Allelic loss at the MEG3 locus is also observed in meningiomas, with increasing prevalence in higher grade tumors. In addition, there is an increase in CpG methylation within the promoter and the imprinting control region of MEG3 gene in meningiomas. Functionally, MEG3 suppresses DNA synthesis in both IOMM-Lee and CH157-MN cells by approximately 60% in bromodeoxyuridine incorporation assays. Colony-forming efficiency assays show that MEG3 inhibits colony formation in CH157-MN cells by approximately 80%. Furthermore, MEG3 stimulates p53-mediated transactivation in these cell lines. Therefore, these data are consistent with the hypothesis that MEG3, which encodes a noncoding RNA, may be a tumor suppressor gene at chromosome 14q32 involved in meningioma progression via a novel mechanism.

Chromosome-encoded narrow-spectrum Ambler class A beta-lactamase GIL-1 from Citrobacter gillenii.

PubMed

Naas, Thierry; Aubert, Daniel; Ozcan, Ayla; Nordmann, Patrice

2007-04-01

A novel beta-lactamase gene was cloned from the whole-cell DNA of an enterobacterial Citrobacter gillenii reference strain that displayed a weak narrow-spectrum beta-lactam-resistant phenotype and was expressed in Escherichia coli. It encoded a clavulanic acid-inhibited Ambler class A beta-lactamase, GIL-1, with a pI value of 7.5 and a molecular mass of ca. 29 kDa. GIL-1 had the highest percent amino acid sequence identity with TEM-1 and SHV-1, 77%, and 67%, respectively, and only 46%, 31%, and 32% amino acid sequence identity with CKO-1 (C. koseri), CdiA1 (C. diversus), and SED-1 (C. sedlaki), respectively. The substrate profile of the purified GIL-1 was similar to that of beta-lactamases TEM-1 and SHV-1. The blaGIL-1 gene was chromosomally located, as revealed by I-CeuI experiments, and was constitutively expressed at a low level in C. gillenii. No gene homologous to the regulatory ampR genes of chromosomal class C beta-lactamases was found upstream of the blaGIL-1 gene, which fits the noninducibility of beta-lactamase expression in C. gillenii. Rapid amplification of DNA 5' ends analysis of the promoter region revealed putative promoter sequences that diverge from what has been identified as the consensus sequence in E. coli. The blaGIL-1 gene was part of a 5.5-kb DNA fragment bracketed by a 9-bp duplication and inserted between the d-lactate dehydrogenase gene and the ydbH genes; this DNA fragment was absent in other Citrobacter species. This work further illustrates the heterogeneity of beta-lactamases in Citrobacter spp., which may indicate that the variability of Citrobacter species is greater than expected.

Characterization of a highly conserved human homolog to the chicken neural cell surface protein Bravo/Nr-CAM that maps to chromosome band 7q31

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

Lane, R.P.; Vielmetter, J.; Dreyer, W.J.

1996-08-01

The neuronal cell adhesion molecule Bravo/Nr-CAM is a cell surface protein of the immunoglobulin (Ig) superfamily and is closely related to the L1/NgCAM and neurofascin molecules, all of which contain six immunoglobulin domains, five fibronectin repeats, a transmembrane region, and an intracellular domain. Chicken Bravo/Nr-CAM has been shown to interact with other cell surface molecules of the Ig superfamily and has been implicated in specific pathfinding roles of axonal growth cones in the developing nervous system. We now report the characterization of cDNA clones encoding the human Bravo/Nr-CAM protein, which, like its chicken homolog, is composed of six V-like Igmore » domains and five fibronectin type III repeats. The human Bravo/Nr-CAM homolog also contains a transmembrane and intracellular domain, both of which are 100% conserved at the amino acid level compared to its chicken homolog. Overall, the human Bravo/Nr-CAM homolog is 82% identical to the chicken Bravo/Nr-CAM amino acid sequence. Independent cDNAs encoding four different isoforms were also identified, all of which contain alternatively spliced variants around the fifth fibronectin type III repeat, including one isoform that had been previously identified for chicken Bravo/Nr-CAM. Northern blot analysis reveals one mRNA species of approximately 7.0 kb in adult human brain tissue. Fluorescence in situ hybridization maps the gene for human Bravo/Nr-CAM to human chromosome 7q31.1-q31.2. This chromosomal locus has been previously identified as containing a tumore suppressor candidate gene commonly deleted in certain human cancer tissues. 38 refs., 5 figs.« less

Cloning and characterization of a novel zinc finger gene in Xp11.2

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

Derry, J.M.J.; Jess, U.; Francke, U.

1995-11-20

During a systematic search for open reading frames in chromosome band Xp11.2, a novel gene (ZNF157) that encodes a putative 506-amino-acid protein with the sequence characteristics of a zinc-finger-containing transcription factor was isolated. ZNF157 is encoded by four exons distributed over >20 kb of genomic DNA. The second and third exons contain sequences similar to those of the previously described KRAB-A and KRAB-B domains, motifs that have been shown to mediate transcriptional repression in other members of the protein family. A fourth exon contains 12 zinc finger DNA binding motifs and finger linking regions characteristic of ZNF proteins of themore » Krueppel family. ZNF157 maps to the telomeric end of a cluster of ZNF genes that includes ZNF21, ZNF41, and ZNF81. 19 refs., 2 figs.« less

Susceptibility to Dental Caries and the Salivary Proline-Rich Proteins

PubMed Central

Levine, Martin

2011-01-01

Early childhood caries affects 28% of children aged 2–6 in the US and is not decreasing. There is a well-recognized need to identify susceptible children at birth. Caries-free adults neutralize bacterial acids in dental biofilms better than adults with severe caries. Saliva contains acidic and basic proline-rich proteins (PRPs) which attach to oral streptococci. The PRPs are encoded within a small region of chromosome 12. An acidic PRP allele (Db) protects Caucasian children from caries but is more common in African Americans. Some basic PRP allelic phenotypes have a three-fold greater frequency in caries-free adults than in those with severe caries. Early childhood caries may associate with an absence of certain basic PRP alleles which bind oral streptococci, neutralize biofilm acids, and are in linkage disequilibrium with Db in Caucasians. The encoding of basic PRP alleles is updated and a new technology for genotyping them is described. PMID:22190937

Human Autoantibodies Reveal Titin as a Chromosomal Protein

PubMed Central

Machado, Cristina; Sunkel, Claudio E.; Andrew, Deborah J.

1998-01-01

Assembly of the higher-order structure of mitotic chromosomes is a prerequisite for proper chromosome condensation, segregation and integrity. Understanding the details of this process has been limited because very few proteins involved in the assembly of chromosome structure have been discovered. Using a human autoimmune scleroderma serum that identifies a chromosomal protein in human cells and Drosophila embryos, we cloned the corresponding Drosophila gene that encodes the homologue of vertebrate titin based on protein size, sequence similarity, developmental expression and subcellular localization. Titin is a giant sarcomeric protein responsible for the elasticity of striated muscle that may also function as a molecular scaffold for myofibrillar assembly. Molecular analysis and immunostaining with antibodies to multiple titin epitopes indicates that the chromosomal and muscle forms of titin may vary in their NH2 termini. The identification of titin as a chromosomal component provides a molecular basis for chromosome structure and elasticity. PMID:9548712

The virulence gene cluster of Listeria monocytogenes is also present in Listeria ivanovii, an animal pathogen, and Listeria seeligeri, a nonpathogenic species.

PubMed Central

Gouin, E; Mengaud, J; Cossart, P

1994-01-01

Most known Listeria monocytogenes virulence genes cluster within a 9.6-kb chromosomal region. This region is flanked on one end by two uncharacterized open reading frames (ORF A and ORF B) and ldh, an ORF presumably encoding the L. monocytogenes lactate dehydrogenase (J.-A. Vazquez-Boland, C. Kocks, S. Dramsi, H. Ohayon, C. Geoffroy, J. Mengaud, and P. Cossart, Infect. Immun. 60:219-230, 1992). We report here that the other end is flanked by prs, and ORF homologous to phosphoribosyl PPi synthetase genes. ORF B and prs were detected in all Listeria species and thus delimit the virulence region. This virulence gene cluster was detected exclusively in hemolytic Listeria species, Listeria ivanovii, an animal pathogen, and Listeria seeligeri, a nonpathogenic species. Images PMID:8039927

Glioblastoma adaptation traced through decline of an IDH1 clonal driver and macro-evolution of a double-minute chromosome

PubMed Central

Favero, F.; McGranahan, N.; Salm, M.; Birkbak, N. J.; Sanborn, J. Z.; Benz, S. C.; Becq, J.; Peden, J. F.; Kingsbury, Z.; Grocok, R. J.; Humphray, S.; Bentley, D.; Spencer-Dene, B.; Gutteridge, A.; Brada, M.; Roger, S.; Dietrich, P.-Y.; Forshew, T.; Gerlinger, M.; Rowan, A.; Stamp, G.; Eklund, A. C.; Szallasi, Z.; Swanton, C.

2015-01-01

Background Glioblastoma (GBM) is the most common malignant brain cancer occurring in adults, and is associated with dismal outcome and few therapeutic options. GBM has been shown to predominantly disrupt three core pathways through somatic aberrations, rendering it ideal for precision medicine approaches. Methods We describe a 35-year-old female patient with recurrent GBM following surgical removal of the primary tumour, adjuvant treatment with temozolomide and a 3-year disease-free period. Rapid whole-genome sequencing (WGS) of three separate tumour regions at recurrence was carried out and interpreted relative to WGS of two regions of the primary tumour. Results We found extensive mutational and copy-number heterogeneity within the primary tumour. We identified a TP53 mutation and two focal amplifications involving PDGFRA, KIT and CDK4, on chromosomes 4 and 12. A clonal IDH1 R132H mutation in the primary, a known GBM driver event, was detectable at only very low frequency in the recurrent tumour. After sub-clonal diversification, evidence was found for a whole-genome doubling event and a translocation between the amplified regions of PDGFRA, KIT and CDK4, encoded within a double-minute chromosome also incorporating miR26a-2. The WGS analysis uncovered progressive evolution of the double-minute chromosome converging on the KIT/PDGFRA/PI3K/mTOR axis, superseding the IDH1 mutation in dominance in a mutually exclusive manner at recurrence, consequently the patient was treated with imatinib. Despite rapid sequencing and cancer genome-guided therapy against amplified oncogenes, the disease progressed, and the patient died shortly after. Conclusion This case sheds light on the dynamic evolution of a GBM tumour, defining the origins of the lethal sub-clone, the macro-evolutionary genomic events dominating the disease at recurrence and the loss of a clonal driver. Even in the era of rapid WGS analysis, cases such as this illustrate the significant hurdles for precision medicine success. PMID:25732040

The gene for pancreatic polypeptide (PPY) and the anonymous marker D17S78 are within 45 kb of each other on chromosome 17q21

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

Chandrasekharappa, S.C.; King, S.E.; Lee, Y.H.

1994-05-15

A gene for early-onset breast and ovarian cancer (BRCA1) has been localized to a small region of chromosome 17q21. A combination of genetic linkage studies, radiation-reduced hybrid analysis, and physical mapping by FISH has identified several genes/markers that lie in this interval. Among these are the gene encoding pancreatic polypeptide (PPY) and a polymorphic marker at locus D17S78. Efforts to construct a physical map of this region by isolating a large number of yeast artificial chromosome (YAC) and cosmid clones demonstrate that PPY and D17S78 are present within the same cosmid clone, and therefore no farther than 45 kb apart.more » This observation takes on particular significance since it excludes a recently described BRCA1 candidate gene from the interval defined by meiotic mapping. Although PPY and D17S78 were found to be no farther than 45 kb apart, identification of a smaller fragment that hybridizes to both probes would indicate that these two are much closer. The probe p131 and the gene PPY were previously mapped to 17q21-q23 and to the proximal long arm of chromosome 17, respectively. The demonstration of the close proximity of these markers should allow them to be treated as a single locus in terms of long-range genomic mapping of this region, and the genomic clones isolated should serve as useful resources for the identification of the BRCA1 gene. Analysis of a large number of a familial and spordic breast and ovarian cancers has identified frequent loss of heterozygosity near the BRCA1 locus. A recent report has suggested the responsible interval lies just telomeric to PPY, and a suggested candidate gene (MCD) for BRCA1 was found to be somatically rearranged in two of several hundred sporadic breast tumors.« less

Genomic and transcriptomic comparison of allergen and silver nanoparticle-induced mast cell degranulation reveals novel non-immunoglobulin E mediated mechanisms.

PubMed

Johnson, Monica; Alsaleh, Nasser; Mendoza, Ryan P; Persaud, Indushekhar; Bauer, Alison K; Saba, Laura; Brown, Jared M

2018-01-01

Mast cells represent a crucial cell type in host defense; however, maladaptive responses are contributing factors in the pathogenesis of allergic diseases. Previous work in our laboratory has shown that exposure to silver nanoparticles (AgNPs) results in mast cell degranulation via a non-immunoglobulin E (IgE) mechanism. In this study, we utilized a systems biology approach to identify novel genetic factors playing a role in AgNP-induced mast cell degranulation compared to the classical activation by antigen-mediated FcεRI crosslinking. Mast cell degranulation was assessed in bone marrow-derived mast cells isolated from 23 strains of mice following exposure to AgNPs or FcεRI crosslinking with dinitrophenyl (DNP). Utilizing strain-dependent mast cell degranulation, an association mapping study identified 3 chromosomal regions that were significantly associated with mast cell degranulation by AgNP and one non-overlapping region associated with DNP-mediated degranulation. Two of the AgNP-associated regions correspond to genes previously reported to be associated with allergic disorders (Trac2 on chromosome 1 and Traf6 on chromosome 2) and an uncharacterized gene identified on chromosome 1 (Fam126b). In conjunction, RNA-sequencing performed on mast cells from the high and low responder strains revealed 3754 and 34 differentially expressed genes that were unique to DNP and AgNP exposures, respectively. Select candidate genes include Ptger4, a gene encoding a G-protein coupled receptor in addition to a multifunctional adaptor protein, Txnip, that may be driving mast cell degranulation by AgNP. Taken together, we identified novel genes that have not been previously shown to play a role in nanoparticle-mediated mast cell activation. With further functional evaluation in the future, these genes may be potential therapeutic targets in the treatment of non-IgE mediated mast cell-linked disorders.

True hermaphroditism in a 46, XY individual, caused by a postzygotic somatic point mutation in the male gonadal sex-determining locus (SRY): Molecular genetics and histological findings in a sporadic case

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

Braun, A.; Kammerer, S.; Cleve, H.

1993-03-01

Recently, the gene for the determination of maleness has been identified in the sex-determining region on the short arm of the Y chromosome (SRY) between the Y-chromosomal pseudoautosomal boundary (PABY) and the ZFY gene locus. Experiments with transgenic mice confirmed that SRY is a part of the testis-determining factor (TDF). The authors describe a sporadic case of a patient with intersexual genitalia and the histological finding of ovotestes in the gonad, which resembles the mixed type of gonadal tissue without primordial follicle structures. The karyotype of the patient was 46,XY. By PCR amplification, they tested for the presence of SRYmore » by using DNA obtained from histological gonadal slices. The SRY products of both DNA preparations were further analyzed by direct sequencing. All three parts of the sex-determining region of the Y chromosome could be amplified from leukocytic DNA. The patient's and the father's SRY sequences were identical with the published sequence. In the SRY PCR product of gonadal DNA, the wild-type and two point mutations were present in the patient's sequence, simulating a heterozygous state of a Y-chromosomal gene: one of the mutations was silent, while the other encoded for a nonconservative amino acid substitution from leucine to histidine. Subcloning procedures showed that the two point mutations always occurred together. The origin of the patient's intersexuality is a postzygotic mutation of the SRY occurring in part of the gonadal tissue. This event caused the loss of the testis-determining function in affected cells. 37 refs., 6 figs.« less

Sex determining gene on the X chromosome short arm: dosage sensitive sex reversal.

PubMed

Ogata, T; Matsuo, N

1996-08-01

The present review article summarizes current knowledge concerning the sex determining gene on Xp21, termed DSS (dosage sensitive sex reversal). The presence of DSS has been based on the finding that, in the presence of SRY, partial active Xp duplications encompassing the middle part of Xp result in sex reversal, whereas those of the distal or proximal part of Xp permit male sex development. Because Klinefelter patients develop as males, it is believed that DSS is normally subject to X-inactivation, and that two active copies of DSS override the function of SRY, resulting in gonadal dysgenesis because of meiotic pairing failure. It may be possible that DSS encodes a target sequence for repressing function of SRY or that DSS is involved in an X chromosome-counting mechanism. Molecular approaches have localized DSS to a 160 kb region and isolated candidate genes such as DAX-1 and MAGE-Xp, but there has been no formal evidence equating the candidate gene with DSS. In addition to its clinical importance, the exploration of DSS must provide a useful clue to phylogenetic studies of sex chromosomes and dosage compensation.

The vertebrate ancestral repertoire of visual opsins, transducin alpha subunits and oxytocin/vasopressin receptors was established by duplication of their shared genomic region in the two rounds of early vertebrate genome duplications.

PubMed

Lagman, David; Ocampo Daza, Daniel; Widmark, Jenny; Abalo, Xesús M; Sundström, Görel; Larhammar, Dan

2013-11-02

Vertebrate color vision is dependent on four major color opsin subtypes: RH2 (green opsin), SWS1 (ultraviolet opsin), SWS2 (blue opsin), and LWS (red opsin). Together with the dim-light receptor rhodopsin (RH1), these form the family of vertebrate visual opsins. Vertebrate genomes contain many multi-membered gene families that can largely be explained by the two rounds of whole genome duplication (WGD) in the vertebrate ancestor (2R) followed by a third round in the teleost ancestor (3R). Related chromosome regions resulting from WGD or block duplications are said to form a paralogon. We describe here a paralogon containing the genes for visual opsins, the G-protein alpha subunit families for transducin (GNAT) and adenylyl cyclase inhibition (GNAI), the oxytocin and vasopressin receptors (OT/VP-R), and the L-type voltage-gated calcium channels (CACNA1-L). Sequence-based phylogenies and analyses of conserved synteny show that the above-mentioned gene families, and many neighboring gene families, expanded in the early vertebrate WGDs. This allows us to deduce the following evolutionary scenario: The vertebrate ancestor had a chromosome containing the genes for two visual opsins, one GNAT, one GNAI, two OT/VP-Rs and one CACNA1-L gene. This chromosome was quadrupled in 2R. Subsequent gene losses resulted in a set of five visual opsin genes, three GNAT and GNAI genes, six OT/VP-R genes and four CACNA1-L genes. These regions were duplicated again in 3R resulting in additional teleost genes for some of the families. Major chromosomal rearrangements have taken place in the teleost genomes. By comparison with the corresponding chromosomal regions in the spotted gar, which diverged prior to 3R, we could time these rearrangements to post-3R. We present an extensive analysis of the paralogon housing the visual opsin, GNAT and GNAI, OT/VP-R, and CACNA1-L gene families. The combined data imply that the early vertebrate WGD events contributed to the evolution of vision and the other neuronal and neuroendocrine functions exerted by the proteins encoded by these gene families. In pouched lamprey all five visual opsin genes have previously been identified, suggesting that lampreys diverged from the jawed vertebrates after 2R.

Recurrent Rearrangement during Adaptive Evolution in an Interspecific Yeast Hybrid Suggests a Model for Rapid Introgression

PubMed Central

Dunn, Barbara; Paulish, Terry; Stanbery, Alison; Piotrowski, Jeff; Koniges, Gregory; Kroll, Evgueny; Louis, Edward J.; Liti, Gianni; Sherlock, Gavin; Rosenzweig, Frank

2013-01-01

Genome rearrangements are associated with eukaryotic evolutionary processes ranging from tumorigenesis to speciation. Rearrangements are especially common following interspecific hybridization, and some of these could be expected to have strong selective value. To test this expectation we created de novo interspecific yeast hybrids between two diverged but largely syntenic Saccharomyces species, S. cerevisiae and S. uvarum, then experimentally evolved them under continuous ammonium limitation. We discovered that a characteristic interspecific genome rearrangement arose multiple times in independently evolved populations. We uncovered nine different breakpoints, all occurring in a narrow ∼1-kb region of chromosome 14, and all producing an “interspecific fusion junction” within the MEP2 gene coding sequence, such that the 5′ portion derives from S. cerevisiae and the 3′ portion derives from S. uvarum. In most cases the rearrangements altered both chromosomes, resulting in what can be considered to be an introgression of a several-kb region of S. uvarum into an otherwise intact S. cerevisiae chromosome 14, while the homeologous S. uvarum chromosome 14 experienced an interspecific reciprocal translocation at the same breakpoint within MEP2, yielding a chimaeric chromosome; these events result in the presence in the cell of two MEP2 fusion genes having identical breakpoints. Given that MEP2 encodes for a high-affinity ammonium permease, that MEP2 fusion genes arise repeatedly under ammonium-limitation, and that three independent evolved isolates carrying MEP2 fusion genes are each more fit than their common ancestor, the novel MEP2 fusion genes are very likely adaptive under ammonium limitation. Our results suggest that, when homoploid hybrids form, the admixture of two genomes enables swift and otherwise unavailable evolutionary innovations. Furthermore, the architecture of the MEP2 rearrangement suggests a model for rapid introgression, a phenomenon seen in numerous eukaryotic phyla, that does not require repeated backcrossing to one of the parental species. PMID:23555283

Alternative splicing for members of human mosaic domain superfamilies. I. The CH and LIM domains containing group of proteins.

PubMed

Friedberg, Felix

2009-05-01

In this paper we examine (restricted to homo sapiens) the products resulting from gene duplication and the subsequent alternative splicing for the members of a multidomain group of proteins which possess the evolutionary conserved calponin homology CH domain, i.e. an "actin binding domain", as a singlet and which, in addition, contain the conserved cysteine rich double Zn finger possessing Lim domain, also as a singlet. Seven genes, resulting from gene duplications, were identified that code for seven group members for which pre-mRNAs appear to have undergone multiple alternative splicing: Mical 1, 2 and 3 are located on chromosomes 6q21, 11p15 and 22q11, respectively. The LMO7 gene is present on chromosome 13q22 and the LIMCH1 gene on chromosome 4p13. Micall1 is mapped to chromosome 22q13 and Micall2 to chromosome 7p22. Translated Gen/Bank ESTs suggest the existence of multiple products alternatively spliced from the pre-mRNAs encoded by these genes. Characteristic indicators of such splicing among the proteins derived from one gene must include containment of some common extensive 100% identical regions. In some instances only one exon might be partly or completely eliminated. Sometimes alternative splicing is also associated with an increased frequency of creation of an exon or part of an exon from an intron. Not only coding regions for the body of the protein but also for its N- or -C ends could be affected by the splicing. If created forms are merely beginning at different starting points but remain identical in sequence thereafter, their existence as products of alternate splicing must be questioned. In the splicings, described in this paper, multiple isoforms rather than a single isoform appear as products during the gene expression.

A Portrait of Ribosomal DNA Contacts with Hi-C Reveals 5S and 45S rDNA Anchoring Points in the Folded Human Genome

PubMed Central

Yu, Shoukai; Lemos, Bernardo

2016-01-01

Ribosomal RNAs (rRNAs) account for >60% of all RNAs in eukaryotic cells and are encoded in the ribosomal DNA (rDNA) arrays. The rRNAs are produced from two sets of loci: the 5S rDNA array resides exclusively on human chromosome 1, whereas the 45S rDNA array resides on the short arm of five human acrocentric chromosomes. The 45S rDNA gives origin to the nucleolus, the nuclear organelle that is the site of ribosome biogenesis. Intriguingly, 5S and 45S rDNA arrays exhibit correlated copy number variation in lymphoblastoid cells (LCLs). Here we examined the genomic architecture and repeat content of the 5S and 45S rDNA arrays in multiple human genome assemblies (including PacBio MHAP assembly) and ascertained contacts between the rDNA arrays and the rest of the genome using Hi-C datasets from two human cell lines (erythroleukemia K562 and lymphoblastoid cells). Our analyses revealed that 5S and 45S arrays each have thousands of contacts in the folded genome, with rDNA-associated regions and genes dispersed across all chromosomes. The rDNA contact map displayed conserved and disparate features between two cell lines, and pointed to specific chromosomes, genomic regions, and genes with evidence of spatial proximity to the rDNA arrays; the data also showed a lack of direct physical interaction between the 5S and 45S rDNA arrays. Finally, the analysis identified an intriguing organization in the 5S array with Alu and 5S elements adjacent to one another and organized in opposite orientation along the array. Portraits of genome folding centered on the ribosomal DNA array could help understand the emergence of concerted variation, the control of 5S and 45S expression, as well as provide insights into an organelle that contributes to the spatial localization of human chromosomes during interphase. PMID:27797956

Polymyxins: Antibacterial Activity, Susceptibility Testing, and Resistance Mechanisms Encoded by Plasmids or Chromosomes

PubMed Central

Jayol, Aurélie; Nordmann, Patrice

2017-01-01

SUMMARY Polymyxins are well-established antibiotics that have recently regained significant interest as a consequence of the increasing incidence of infections due to multidrug-resistant Gram-negative bacteria. Colistin and polymyxin B are being seriously reconsidered as last-resort antibiotics in many areas where multidrug resistance is observed in clinical medicine. In parallel, the heavy use of polymyxins in veterinary medicine is currently being reconsidered due to increased reports of polymyxin-resistant bacteria. Susceptibility testing is challenging with polymyxins, and currently available techniques are presented here. Genotypic and phenotypic methods that provide relevant information for diagnostic laboratories are presented. This review also presents recent works in relation to recently identified mechanisms of polymyxin resistance, including chromosomally encoded resistance traits as well as the recently identified plasmid-encoded polymyxin resistance determinant MCR-1. Epidemiological features summarizing the current knowledge in that field are presented. PMID:28275006

DNA sequence analysis of a 10 624 bp fragment of the left arm of chromosome XV from Saccharomyces cerevisiae reveals a RNA binding protein, a mitochondrial protein, two ribosomal proteins and two new open reading frames.

PubMed

Lafuente, M J; Gamo, F J; Gancedo, C

1996-09-01

We have determined the sequence of a 10624 bp DNA segment located in the left arm of chromosome XV of Saccharomyces cerevisiae. The sequence contains eight open reading frames (ORFs) longer than 100 amino acids. Two of them do not present significant homology with sequences found in the databases. The product of ORF o0553 is identical to the protein encoded by the gene SMF1. Internal to it there is another ORF, o0555 that is apparently expressed. The proteins encoded by ORFs o0559 and o0565 are identical to ribosomal proteins S19.e and L18 respectively. ORF o0550 encodes a protein with an RNA binding signature including RNP motifs and stretches rich in asparagine, glutamine and arginine.

The Oxytricha trifallax Macronuclear Genome: A Complex Eukaryotic Genome with 16,000 Tiny Chromosomes

PubMed Central

Swart, Estienne C.; Bracht, John R.; Magrini, Vincent; Minx, Patrick; Chen, Xiao; Zhou, Yi; Khurana, Jaspreet S.; Goldman, Aaron D.; Nowacki, Mariusz; Schotanus, Klaas; Jung, Seolkyoung; Fulton, Robert S.; Ly, Amy; McGrath, Sean; Haub, Kevin; Wiggins, Jessica L.; Storton, Donna; Matese, John C.; Parsons, Lance; Chang, Wei-Jen; Bowen, Michael S.; Stover, Nicholas A.; Jones, Thomas A.; Eddy, Sean R.; Herrick, Glenn A.; Doak, Thomas G.; Wilson, Richard K.; Mardis, Elaine R.; Landweber, Laura F.

2013-01-01

The macronuclear genome of the ciliate Oxytricha trifallax displays an extreme and unique eukaryotic genome architecture with extensive genomic variation. During sexual genome development, the expressed, somatic macronuclear genome is whittled down to the genic portion of a small fraction (∼5%) of its precursor “silent” germline micronuclear genome by a process of “unscrambling” and fragmentation. The tiny macronuclear “nanochromosomes” typically encode single, protein-coding genes (a small portion, 10%, encode 2–8 genes), have minimal noncoding regions, and are differentially amplified to an average of ∼2,000 copies. We report the high-quality genome assembly of ∼16,000 complete nanochromosomes (∼50 Mb haploid genome size) that vary from 469 bp to 66 kb long (mean ∼3.2 kb) and encode ∼18,500 genes. Alternative DNA fragmentation processes ∼10% of the nanochromosomes into multiple isoforms that usually encode complete genes. Nucleotide diversity in the macronucleus is very high (SNP heterozygosity is ∼4.0%), suggesting that Oxytricha trifallax may have one of the largest known effective population sizes of eukaryotes. Comparison to other ciliates with nonscrambled genomes and long macronuclear chromosomes (on the order of 100 kb) suggests several candidate proteins that could be involved in genome rearrangement, including domesticated MULE and IS1595-like DDE transposases. The assembly of the highly fragmented Oxytricha macronuclear genome is the first completed genome with such an unusual architecture. This genome sequence provides tantalizing glimpses into novel molecular biology and evolution. For example, Oxytricha maintains tens of millions of telomeres per cell and has also evolved an intriguing expansion of telomere end-binding proteins. In conjunction with the micronuclear genome in progress, the O. trifallax macronuclear genome will provide an invaluable resource for investigating programmed genome rearrangements, complementing studies of rearrangements arising during evolution and disease. PMID:23382650

Cloning and sequencing of an alkaline protease gene from Bacillus lentus and amplification of the gene on the B. lentus chromosome by an improved technique.

PubMed

Jørgensen, P L; Tangney, M; Pedersen, P E; Hastrup, S; Diderichsen, B; Jørgensen, S T

2000-02-01

A gene encoding an alkaline protease was cloned from an alkalophilic bacillus, and its nucleotide sequence was determined. The cloned gene was used to increase the copy number of the protease gene on the chromosome by an improved gene amplification technique.

Genomic organization and chromosomal localization of the gene TCF15 encoding the early mesodermal basic helix-loop-helix factor bHLH-EC2

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

Hidai, H.; Quertermous, E.E.; Quertermous, T.

1995-12-10

bHLH-EC2 is a recently characterized member of a growing family of basic helix-loop-helix transcription factors. This family includes bHLH factors such as twist, which appear to be primarily involved in early mesodermal differentiation, and bHLH factors such as TAL-1, which have been characterized through their association with chromosomal breakpoints associated with T-cell leukemias. To provide for studies aimed at understanding the genetic regulation of bHLH-EC2, we have characterized the organization of this gene and conducted preliminary studies of the transcriptional activity of the upstream promoter region. The mouse bHLH-EC2 gene was found to consist of two exons separated by amore » 5-kb intron, an organization pattern similar to the mouse twist gene. The transcription initiation site was identified by RNase protection assay and primer extension analysis. Linked promoter-reporter gene transfection experiments in cultured cells indicated that while the identified upstream sequence can function to promote transcription, it does not function in a cell-specific fashion. To investigate the possible association of bHLH-EC2 with hematological malignancy, the chromosomal location of this gene in the human was mapped by fluorescence in situ hybridization and assigned to chromosome band 20p13. 16 refs., 3 figs.« less

Targeted tandem duplication of a large chromosomal segment in Aspergillus oryzae.

PubMed

Takahashi, Tadashi; Sato, Atsushi; Ogawa, Masahiro; Hanya, Yoshiki; Oguma, Tetsuya

2014-08-01

We describe here the first successful construction of a targeted tandem duplication of a large chromosomal segment in Aspergillus oryzae. The targeted tandem chromosomal duplication was achieved by using strains that had a 5'-deleted pyrG upstream of the region targeted for tandem chromosomal duplication and a 3'-deleted pyrG downstream of the target region. Consequently,strains bearing a 210-kb targeted tandem chromosomal duplication near the centromeric region of chromosome 8 and strains bearing a targeted tandem chromosomal duplication of a 700-kb region of chromosome 2 were successfully constructed. The strains bearing the tandem chromosomal duplication were efficiently obtained from the regenerated protoplast of the parental strains. However, the generation of the chromosomal duplication did not depend on the introduction of double-stranded breaks(DSBs) by I-SceI. The chromosomal duplications of these strains were stably maintained after five generations of culture under nonselective conditions. The strains bearing the tandem chromosomal duplication in the 700-kb region of chromosome 2 showed highly increased protease activity in solid-state culture, indicating that the duplication of large chromosomal segments could be a useful new breeding technology and gene analysis method.

Genomic cloning and chromosomal localization of HRY, the human homolog to the Drosophila segmentation gene, hairy

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

Feder, J.N.; Jan, L.Y.; Jan, Y.N.

The Drosophila hairy gene encodes a basic helix- loop-helix protein that functions in at least two steps during Drosophila development: (1) during embryogenesis, when it partakes in the establishment of segments, and (2) during the larval stage, when it functions negatively in determining the pattern of sensory bristles on the adult fly. In the rat, a structurally homologous gene (RHL) behaves as an immediate-early gene in its response to growth factors and can, like that in Drosophila, suppress neuronal differentiation events. Here, the authors report the genomic cloning of the human hairy gene homolog (HRY). The coding region of themore » gene is contained within four exons. The predicted amino acid sequence reveals only four amino acid differences between the human and rat genes. Analysis of the DNA sequence 5[prime] to the coding region reveals a putatitve untranslated exon. To increase the value of the HRY gene as a genetic marker and to assess its potential involvement in genetic disorders, they sublocalized the locus to chromosome 3q28-q29 by fluorescence in situ hybridization. 34 refs., 4 figs., 1 tab.« less

Structural organization and chromosomal assignment of the mouse embryonic TEA domain-containing factor (ETF) gene

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

Suzuki, Kazuo; Yasunami, Michio; Matsuda, Yoichi

1996-09-01

Embryonic TEA domain-containing factor (ETF) belongs to the family of proteins structurally related to transcriptional enhancer factor-1 (TEF-1) and is implicated in neural development. Isolation and characterization of the cosmid clones encoding the mouse ETF gene (Etdf) revealed that Etdf spans approximately 17.9 kb and consists of 12 exons. The exon-intron structure of Etdf closely resembles that of the Drosophila scalloped gene, indicating that these genes may have evolved from a common ancestor. Then multiple transcription initiation sites revealed by S1 protection and primer extension analyses are consistent with the absence of the canonical TATA and CAAT boxes in themore » 5{prime}-flanking region, which contains many potential regulatory sequences, such as the E-box, N-box, Sp1 element, GATA-1 element, TAATGARAT element, and B2 short interspersed element (SINE) as well as several direct and inverted repeat sequences. The Etdf locus was assigned to the proximal region of mouse chromosome 7 using fluorescence in situ hybridization and linkage mapping analyses. These results provide the molecular basis for studying the regulation, in vivo function, and evolution of Etdf. 29 refs., 5 figs., 1 tab.« less

Structural organization and chromosomal assignment of the mouse embryonic TEA domain-containing factor (ETF) gene.

PubMed

Suzuki, K; Yasunami, M; Matsuda, Y; Maeda, T; Kobayashi, H; Terasaki, H; Ohkubo, H

1996-09-01

Embryonic TEA domain-containing factor (ETF) belongs to the family of proteins structurally related to transcriptional enhancer factor-1 (TEF-1) and is implicated in neural development. Isolation and characterization of the cosmid clones encoding the mouse ETF gene (Etdf) revealed that Etdf spans approximately 17.9 kb and consists of 12 exons. The exon-intron structure of Etdf closely resembles that of the Drosophila scalloped gene, indicating that these genes may have evolved from a common ancestor. The multiple transcription initiation sites revealed by S1 protection and primer extension analyses are consistent with the absence of the canonical TATA and CAAT boxes in the 5'-flanking region, which contains many potential regulatory sequences, such as the E-box, N-box, Sp1 element, GATA-1 element, TAATGARAT element, and B2 short interspersed element (SINE) as well as several direct and inverted repeat sequences. The Etdf locus was assigned to the proximal region of mouse chromosome 7 using fluorescence in situ hybridization and linkage mapping analyses. These results provide the molecular basis for studying the regulation, in vivo function, and evolution of Etdf.

The protocadherin 11X/Y (PCDH11X/Y) gene pair as determinant of cerebral asymmetry in modern Homo sapiens.

PubMed

Priddle, Thomas H; Crow, Timothy J

2013-06-01

Annett's right-shift theory proposes that human cerebral dominance (the functional and anatomical asymmetry or torque along the antero-posterior axis) and handedness are determined by a single "right-shift" gene. Familial transmission of handedness and specific deviations of cerebral dominance in sex chromosome aneuploidies implicate a locus within an X-Y homologous region of the sex chromosomes. The Xq21.3/Yp11.2 human-specific region of homology includes the protocadherin 11X/Y (PCDH11X/Y) gene pair, which encode cell adhesion molecules subject to accelerated evolution following the separation of the human and chimpanzee lineages six million years ago. PCDH11X and PCDH11Y, differentially regulated by retinoic acid, are highly expressed in the ventricular zone, subplate, and cortical plate of the developing cerebral cortex. Both proteins interact with β-catenin, a protein that plays a role in determining axis formation and regulating cortical size. In this way, the PCDH11X/Y gene pair determines cerebral asymmetry by initiating the right shift in Homo sapiens. © 2013 New York Academy of Sciences.

Ribosomal frameshifting and transcriptional slippage: From genetic steganography and cryptography to adventitious use.

PubMed

Atkins, John F; Loughran, Gary; Bhatt, Pramod R; Firth, Andrew E; Baranov, Pavel V

2016-09-06

Genetic decoding is not 'frozen' as was earlier thought, but dynamic. One facet of this is frameshifting that often results in synthesis of a C-terminal region encoded by a new frame. Ribosomal frameshifting is utilized for the synthesis of additional products, for regulatory purposes and for translational 'correction' of problem or 'savior' indels. Utilization for synthesis of additional products occurs prominently in the decoding of mobile chromosomal element and viral genomes. One class of regulatory frameshifting of stable chromosomal genes governs cellular polyamine levels from yeasts to humans. In many cases of productively utilized frameshifting, the proportion of ribosomes that frameshift at a shift-prone site is enhanced by specific nascent peptide or mRNA context features. Such mRNA signals, which can be 5' or 3' of the shift site or both, can act by pairing with ribosomal RNA or as stem loops or pseudoknots even with one component being 4 kb 3' from the shift site. Transcriptional realignment at slippage-prone sequences also generates productively utilized products encoded trans-frame with respect to the genomic sequence. This too can be enhanced by nucleic acid structure. Together with dynamic codon redefinition, frameshifting is one of the forms of recoding that enriches gene expression. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

CYP3C1, the first member of a new cytochrome P450 subfamily found in zebrafish (Danio rerio).

PubMed

Corley-Smith, Graham E; Su, Hsiao-Ting; Wang-Buhler, Jun-Lan; Tseng, Hua-Pin; Hu, Chin-Hwa; Hoang, Thuy; Chung, Woon-Gye; Buhler, Donald R

2006-02-24

We report a new cytochrome P450 (CYP) subfamily CYP3C and the cloning through PCR from zebrafish (Danio rerio) of the first member, CYP3C1. The CYP3C1 gene is on Chromosome 3 with 13 ORF exons encoding a 505 amino acid protein which has 44-54% identities with mammalian and teleost CYP3A and CYP3B forms. As evidenced by spectral analysis, the CYP3C1 protein heterologously expressed in yeast is functional. In silico analysis identified, on the same region of the chromosome, three more genes encoding CYP3C1-like proteins that formed a clade with CYP3C1 in a phylogenetic tree. Using RT-PCR, the CYP3C1 mRNA was detected in 1-6dpf embryo/larvae and in adult fish liver and seven extrahepatic tissues. Whole-mount in situ hybridization using a riboprobe demonstrated expression in the brain during 12-120 hpf. At the 120 hpf larval stage, CYP3C1 mRNA was also detected in the pharynx and gastrointestinal tract. TCDD, dexamethasone, and rifampicin, which up-regulated CYP3A65 mRNA in zebrafish larvae, did not alter the CYP3C1 transcript levels suggesting regulatory differences between CYP3A and CYP3C enzymes in this species.

Analysis of the Functions of Recombination-Related Genes in the Generation of Large Chromosomal Deletions by Loop-Out Recombination in Aspergillus oryzae

PubMed Central

Ogawa, Masahiro; Koyama, Yasuji

2012-01-01

Loop-out-type recombination is a type of intrachromosomal recombination followed by the excision of a chromosomal region. The detailed mechanism underlying this recombination and the genes involved in loop-out recombination remain unknown. In the present study, we investigated the functions of ku70, ligD, rad52, rad54, and rdh54 in the construction of large chromosomal deletions via loop-out recombination and the effect of the position of the targeted chromosomal region on the efficiency of loop-out recombination in Aspergillus oryzae. The efficiency of generation of large chromosomal deletions in the near-telomeric region of chromosome 3, including the aflatoxin gene cluster, was compared with that in the near-centromeric region of chromosome 8, including the tannase gene. In the Δku70 and Δku70-rdh54 strains, only precise loop-out recombination occurred in the near-telomeric region. In contrast, in the ΔligD, Δku70-rad52, and Δku70-rad54 strains, unintended chromosomal deletions by illegitimate loop-out recombination occurred in the near-telomeric region. In addition, large chromosomal deletions via loop-out recombination were efficiently achieved in the near-telomeric region, but barely achieved in the near-centromeric region, in the Δku70 strain. Induction of DNA double-strand breaks by I-SceI endonuclease facilitated large chromosomal deletions in the near-centromeric region. These results indicate that ligD, rad52, and rad54 play a role in the generation of large chromosomal deletions via precise loop-out-type recombination in the near-telomeric region and that loop-out recombination between distant sites is restricted in the near-centromeric region by chromosomal structure. PMID:22286092

Molecular cloning and expression of a gene that controls the high-temperature regulon of Escherichia coli.

PubMed Central

Neidhardt, F C; VanBogelen, R A; Lau, E T

1983-01-01

The high-temperature production (HTP) regulon of Escherichia coli consists of a set of operons that are induced coordinately by a shift to a high temperature under the control of a single chromosomal gene called htpR or hin. To identify more components of this regulon, the rates of synthesis of many polypeptides resolved on two-dimensional polyacrylamide gels were measured in various strains by pulse-labeling after a temperature shift-up. A total of 13 polypeptides were found to be heat inducible only in cells bearing a normal htpR gene on the chromosome or on a plasmid; on this basis these polypeptides were designated products of the HTP regulon. Several hybrid plasmids that contain segments of the E. coli chromosome in the 75-min region were found to carry the htpR gene. A restriction map of this region was constructed, and selected fragments were subcloned and tested for the ability to complement an htpR mutant. The polypeptides encoded by these fragments were detected by permitting expression in maxicells, minicells, and chloramphenicol-treated cells. Complementation was accompanied by production of a polypeptide having a molecular weight of approximately 33,000. This polypeptide, designated F33.4, was markedly reduced in amount in an htpR mutant expected to contain very little htpR gene product. Polypeptide F33.4 is postulated to be the product of htpR and to be an effector that controls heat induction of the HTP regulon. Images PMID:6337122

Differential Gene Expression by Lactobacillus plantarum WCFS1 in Response to Phenolic Compounds Reveals New Genes Involved in Tannin Degradation.

PubMed

Reverón, Inés; Jiménez, Natalia; Curiel, José Antonio; Peñas, Elena; López de Felipe, Félix; de Las Rivas, Blanca; Muñoz, Rosario

2017-04-01

Lactobacillus plantarum is a lactic acid bacterium that can degrade food tannins by the successive action of tannase and gallate decarboxylase enzymes. In the L. plantarum genome, the gene encoding the catalytic subunit of gallate decarboxylase ( lpdC , or lp_2945 ) is only 6.5 kb distant from the gene encoding inducible tannase ( L. plantarum tanB [ tanB Lp ], or lp_2956 ). This genomic context suggests concomitant activity and regulation of both enzymatic activities. Reverse transcription analysis revealed that subunits B ( lpdB , or lp_0271 ) and D ( lpdD , or lp_0272 ) of the gallate decarboxylase are cotranscribed, whereas subunit C ( lpdC , or lp_2945 ) is cotranscribed with a gene encoding a transport protein ( gacP , or lp_2943 ). In contrast, the tannase gene is transcribed as a monocistronic mRNA. Investigation of knockout mutations of genes located in this chromosomal region indicated that only mutants of the gallate decarboxylase (subunits B and C), tannase, GacP transport protein, and TanR transcriptional regulator ( lp_2942 ) genes exhibited altered tannin metabolism. The expression profile of genes involved in tannin metabolism was also analyzed in these mutants in the presence of methyl gallate and gallic acid. It is noteworthy that inactivation of tanR suppresses the induction of all genes overexpressed in the presence of methyl gallate and gallic acid. This transcriptional regulator was also induced in the presence of other phenolic compounds, such as kaempferol and myricetin. This study complements the catalog of L. plantarum expression profiles responsive to phenolic compounds, which enable this bacterium to adapt to a plant food environment. IMPORTANCE Lactobacillus plantarum is a bacterial species frequently found in the fermentation of vegetables when tannins are present. L. plantarum strains degrade tannins to the less-toxic pyrogallol by the successive action of tannase and gallate decarboxylase enzymes. The genes encoding these enzymes are located close to each other in the chromosome, suggesting concomitant regulation. Proteins involved in tannin metabolism and regulation, such GacP (gallic acid permease) and TanR (tannin transcriptional regulator), were identified by differential gene expression in knockout mutants with mutations in genes from this region. This study provides insights into the highly coordinated mechanisms that enable L. plantarum to adapt to plant food fermentations. Copyright © 2017 American Society for Microbiology.

Differential Gene Expression by Lactobacillus plantarum WCFS1 in Response to Phenolic Compounds Reveals New Genes Involved in Tannin Degradation

PubMed Central

Reverón, Inés; Jiménez, Natalia; Curiel, José Antonio; Peñas, Elena; López de Felipe, Félix; de las Rivas, Blanca

2017-01-01

ABSTRACT Lactobacillus plantarum is a lactic acid bacterium that can degrade food tannins by the successive action of tannase and gallate decarboxylase enzymes. In the L. plantarum genome, the gene encoding the catalytic subunit of gallate decarboxylase (lpdC, or lp_2945) is only 6.5 kb distant from the gene encoding inducible tannase (L. plantarum tanB [tanBLp], or lp_2956). This genomic context suggests concomitant activity and regulation of both enzymatic activities. Reverse transcription analysis revealed that subunits B (lpdB, or lp_0271) and D (lpdD, or lp_0272) of the gallate decarboxylase are cotranscribed, whereas subunit C (lpdC, or lp_2945) is cotranscribed with a gene encoding a transport protein (gacP, or lp_2943). In contrast, the tannase gene is transcribed as a monocistronic mRNA. Investigation of knockout mutations of genes located in this chromosomal region indicated that only mutants of the gallate decarboxylase (subunits B and C), tannase, GacP transport protein, and TanR transcriptional regulator (lp_2942) genes exhibited altered tannin metabolism. The expression profile of genes involved in tannin metabolism was also analyzed in these mutants in the presence of methyl gallate and gallic acid. It is noteworthy that inactivation of tanR suppresses the induction of all genes overexpressed in the presence of methyl gallate and gallic acid. This transcriptional regulator was also induced in the presence of other phenolic compounds, such as kaempferol and myricetin. This study complements the catalog of L. plantarum expression profiles responsive to phenolic compounds, which enable this bacterium to adapt to a plant food environment. IMPORTANCE Lactobacillus plantarum is a bacterial species frequently found in the fermentation of vegetables when tannins are present. L. plantarum strains degrade tannins to the less-toxic pyrogallol by the successive action of tannase and gallate decarboxylase enzymes. The genes encoding these enzymes are located close to each other in the chromosome, suggesting concomitant regulation. Proteins involved in tannin metabolism and regulation, such GacP (gallic acid permease) and TanR (tannin transcriptional regulator), were identified by differential gene expression in knockout mutants with mutations in genes from this region. This study provides insights into the highly coordinated mechanisms that enable L. plantarum to adapt to plant food fermentations. PMID:28115379

BRG1 and LKB1: tales of two tumor suppressor genes on chromosome 19p and lung cancer.

PubMed

Rodriguez-Nieto, Salvador; Sanchez-Cespedes, Montse

2009-04-01

Losses of heterozygosity (LOH) of the short arm of chromosome 19 are frequent in lung cancer, suggesting that one or more tumor suppressor genes are present in this region. The LKB1 gene, also called STK11, is somatically inactivated through point mutations and large deletions in lung tumors, demonstrating that LKB1 is a target of the LOH of this chromosomal arm. Data from several independent groups have provided information about the profiles of lung tumors with LKB1 inactivation and it is generally agreed that this alteration strongly predominates in non-small cell lung cancer, in particular adenocarcinomas, in smokers. The LKB1 protein has serine-threonine kinase activity and is involved in the regulation of the cell energetic checkpoint through the phosphorylation and activation of adenosine monophosphate-dependent kinase (AMPK). LKB1 is also involved in other processes such as cell polarization, probably through substrates other than AMPK. Interestingly, another gene on chromosome 19p, BRG1, encoding a component of the SWI/SNF chromatin-remodeling complex, has emerged as a tumor suppressor gene that is altered in lung tumors. Similar to LKB1, BRG1 is somatically inactivated by point mutations or large deletions in lung tumors featuring LOH of chromosome 19p. These observations suggest an important role for BRG1 in lung cancer and highlight the need to further our understanding of the function of Brahma/SWI2-related gene 1 (BRG1) in cancer. Finally, simultaneous mutations at LKB1 and BRG1 are common in lung cancer cells, which exemplifies how a single event, LOH of chromosome 19p in this instance, targets two different tumor suppressors.

Quantitative Trait Loci Mapping of Genome Regions Controlling Permethrin Resistance in the Mosquito Aedes aegypti

PubMed Central

Saavedra-Rodriguez, Karla; Strode, Clare; Flores Suarez, Adriana; Fernandez Salas, Ildefonso; Ranson, Hilary; Hemingway, Janet; Black, William C.

2008-01-01

The mosquito Aedes aegypti is the principal vector of dengue and yellow fever flaviviruses. Permethrin is an insecticide used to suppress Ae. aegypti adult populations but metabolic and target site resistance to pyrethroids has evolved in many locations worldwide. Quantitative trait loci (QTL) controlling permethrin survival in Ae. aegypti were mapped in an F3 advanced intercross line. Parents came from a collection of mosquitoes from Isla Mujeres, México, that had been selected for permethrin resistance for two generations and a reference permethrin-susceptible strain originally from New Orleans. Following a 1-hr permethrin exposure, 439 F3 adult mosquitoes were phenotyped as knockdown resistant, knocked down/recovered, or dead. For QTL mapping, single nucleotide polymorphisms (SNPs) were identified at 22 loci with potential antixenobiotic activity including genes encoding cytochrome P450s (CYP), esterases (EST), or glutathione transferases (GST) and at 12 previously mapped loci. Seven antixenobiotic genes mapped to chromosome I, six to chromosome II, and nine to chromosome III. Two QTL of major effect were detected on chromosome III. One corresponds with a SNP previously associated with permethrin resistance in the para sodium channel gene and the second with the CCEunk7o esterase marker. Additional QTL but of relatively minor effect were also found. These included two sex-linked QTL on chromosome I affecting knockdown and recovery and a QTL affecting survival and recovery. On chromosome II, one QTL affecting survival and a second affecting recovery were detected. The patterns confirm that mutations in the para gene cause target-site insensitivity and are the major source of permethrin resistance but that other genes dispersed throughout the genome contribute to recovery and survival of mosquitoes following permethrin exposure. PMID:18723882

Chromosomal mutations and chromosome loss measured in a new human-hamster hybrid cell line, ALC: studies with colcemid, ultraviolet irradiation, and 137Cs gamma-rays

NASA Technical Reports Server (NTRS)

Kraemer, S. M.; Waldren, C. A.; Chatterjee, A. (Principal Investigator)

1997-01-01

Small mutations, megabase deletions, and aneuploidy are involved in carcinogenesis and genetic defects, so it is important to be able to quantify these mutations and understand mechanisms of their creation. We have previously quantified a spectrum of mutations, including megabase deletions, in human chromosome 11, the sole human chromosome in a hamster-human hybrid cell line AL. S1- mutants have lost expression of a human cell surface antigen, S1, which is encoded by the M1C1 gene at 11p13 so that mutants can be detected via a complement-mediated cytotoxicity assay in which S1+ cells are killed and S1- cells survive. But loss of genes located on the tip of the short arm of 11 (11p15.5) is lethal to the AL hybrid, so that mutants that have lost the entire chromosome 11 die and escape detection. To circumvent this, we fused AL with Chinese hamster ovary (CHO) cells to produce a new hybrid, ALC, in which the requirement for maintaining 11p15.5 is relieved, allowing us to detect mutations events involving loss of 11p15.5. We evaluated the usefulness of this hybrid by conducting mutagenesis studies with colcemid, 137Cs gamma-radiation and UV 254 nm light. Colcemid induced 1000 more S1- mutants per unit dose in ALC than in AL; the increase for UV 254 nm light was only two-fold; and the increase for 137Cs gamma-rays was 12-fold. The increase in S1- mutant fraction in ALC cells treated with colcemid and 137Cs gamma-rays were largely due to chromosome loss and 11p deletions often containing a breakpoint within the centromeric region.

Gapless genome assembly of Colletotrichum higginsianum reveals chromosome structure and association of transposable elements with secondary metabolite gene clusters.

PubMed

Dallery, Jean-Félix; Lapalu, Nicolas; Zampounis, Antonios; Pigné, Sandrine; Luyten, Isabelle; Amselem, Joëlle; Wittenberg, Alexander H J; Zhou, Shiguo; de Queiroz, Marisa V; Robin, Guillaume P; Auger, Annie; Hainaut, Matthieu; Henrissat, Bernard; Kim, Ki-Tae; Lee, Yong-Hwan; Lespinet, Olivier; Schwartz, David C; Thon, Michael R; O'Connell, Richard J

2017-08-29

The ascomycete fungus Colletotrichum higginsianum causes anthracnose disease of brassica crops and the model plant Arabidopsis thaliana. Previous versions of the genome sequence were highly fragmented, causing errors in the prediction of protein-coding genes and preventing the analysis of repetitive sequences and genome architecture. Here, we re-sequenced the genome using single-molecule real-time (SMRT) sequencing technology and, in combination with optical map data, this provided a gapless assembly of all twelve chromosomes except for the ribosomal DNA repeat cluster on chromosome 7. The more accurate gene annotation made possible by this new assembly revealed a large repertoire of secondary metabolism (SM) key genes (89) and putative biosynthetic pathways (77 SM gene clusters). The two mini-chromosomes differed from the ten core chromosomes in being repeat- and AT-rich and gene-poor but were significantly enriched with genes encoding putative secreted effector proteins. Transposable elements (TEs) were found to occupy 7% of the genome by length. Certain TE families showed a statistically significant association with effector genes and SM cluster genes and were transcriptionally active at particular stages of fungal development. All 24 subtelomeres were found to contain one of three highly-conserved repeat elements which, by providing sites for homologous recombination, were probably instrumental in four segmental duplications. The gapless genome of C. higginsianum provides access to repeat-rich regions that were previously poorly assembled, notably the mini-chromosomes and subtelomeres, and allowed prediction of the complete SM gene repertoire. It also provides insights into the potential role of TEs in gene and genome evolution and host adaptation in this asexual pathogen.

Restricted utilization of germ-line VH genes in rabbits: implications for inheritance of VH allotypes and generation of antibody diversity.

PubMed

Knight, K L; Becker, R S; DiPietro, L A

1991-01-01

The presence of inherited VH region allotypic specificities, a1, a2 or a3, on nearly all rabbit immunoglobulins has presented a paradox. We know the germline contains hundreds of VH genes, and if we assume that most of these are used in the generation of antibody diversity, then we must ask how have the a allotype-encoding regions been maintained over time? On the other hand, if we assume that only one (or a small number) of these VH gene(s) is (are) used in VDJ gene rearrangements, then, how is antibody diversity generated? To address these questions, we have cloned and determined the nucleotide sequence of the 3'-most germline VH genes from the a1, a2 and a3 chromosomes and shown in each case that the 3'-most H gene, VH1-a1, VH1-a2, or VH1-a3, encodes an a1, a2 or a3 VH region, respectively. Analysis of rearranged VDJ genes from leukemic B cells showed that VH1 was utilized in these rearrangements. Based on these data, we propose that the allelic inheritance of the VH allotypes is explained by the preferential usage of the VH1 gene in VDJ rearrangements. Support for this hypothesis was obtained from analysis of the mutant rabbit Alicia in which most serum Ig molecules do not have VHa allotypic specificities, but instead have so-called VHa-negative Ig molecules. In this rabbit, VH1 is not expressed as it has been deleted. Analysis of cDNA clones from spleen of Alicia rabbits suggests that the expressed VHa-negative molecules also are encoded by a single germline VH gene. Thus, we suggest that nearly all rabbit VH regions are encoded by one to two germline VH genes and that antibody diversity is generated primarily by somatic hypermutation and gene conversion.

Genome-wide association study identified three major QTL for carcass weight including the PLAG1-CHCHD7 QTN for stature in Japanese Black cattle

PubMed Central

2012-01-01

Background Significant quantitative trait loci (QTL) for carcass weight were previously mapped on several chromosomes in Japanese Black half-sib families. Two QTL, CW-1 and CW-2, were narrowed down to 1.1-Mb and 591-kb regions, respectively. Recent advances in genomic tools allowed us to perform a genome-wide association study (GWAS) in cattle to detect associations in a general population and estimate their effect size. Here, we performed a GWAS for carcass weight using 1156 Japanese Black steers. Results Bonferroni-corrected genome-wide significant associations were detected in three chromosomal regions on bovine chromosomes (BTA) 6, 8, and 14. The associated single nucleotide polymorphisms (SNP) on BTA 6 were in linkage disequilibrium with the SNP encoding NCAPG Ile442Met, which was previously identified as a candidate quantitative trait nucleotide for CW-2. In contrast, the most highly associated SNP on BTA 14 was located 2.3-Mb centromeric from the previously identified CW-1 region. Linkage disequilibrium mapping led to a revision of the CW-1 region within a 0.9-Mb interval around the associated SNP, and targeted resequencing followed by association analysis highlighted the quantitative trait nucleotides for bovine stature in the PLAG1-CHCHD7 intergenic region. The association on BTA 8 was accounted for by two SNP on the BovineSNP50 BeadChip and corresponded to CW-3, which was simultaneously detected by linkage analyses using half-sib families. The allele substitution effects of CW-1, CW-2, and CW-3 were 28.4, 35.3, and 35.0 kg per allele, respectively. Conclusion The GWAS revealed the genetic architecture underlying carcass weight variation in Japanese Black cattle in which three major QTL accounted for approximately one-third of the genetic variance. PMID:22607022

The DNA sequence of the human X chromosome

PubMed Central

Ross, Mark T.; Grafham, Darren V.; Coffey, Alison J.; Scherer, Steven; McLay, Kirsten; Muzny, Donna; Platzer, Matthias; Howell, Gareth R.; Burrows, Christine; Bird, Christine P.; Frankish, Adam; Lovell, Frances L.; Howe, Kevin L.; Ashurst, Jennifer L.; Fulton, Robert S.; Sudbrak, Ralf; Wen, Gaiping; Jones, Matthew C.; Hurles, Matthew E.; Andrews, T. Daniel; Scott, Carol E.; Searle, Stephen; Ramser, Juliane; Whittaker, Adam; Deadman, Rebecca; Carter, Nigel P.; Hunt, Sarah E.; Chen, Rui; Cree, Andrew; Gunaratne, Preethi; Havlak, Paul; Hodgson, Anne; Metzker, Michael L.; Richards, Stephen; Scott, Graham; Steffen, David; Sodergren, Erica; Wheeler, David A.; Worley, Kim C.; Ainscough, Rachael; Ambrose, Kerrie D.; Ansari-Lari, M. Ali; Aradhya, Swaroop; Ashwell, Robert I. S.; Babbage, Anne K.; Bagguley, Claire L.; Ballabio, Andrea; Banerjee, Ruby; Barker, Gary E.; Barlow, Karen F.; Barrett, Ian P.; Bates, Karen N.; Beare, David M.; Beasley, Helen; Beasley, Oliver; Beck, Alfred; Bethel, Graeme; Blechschmidt, Karin; Brady, Nicola; Bray-Allen, Sarah; Bridgeman, Anne M.; Brown, Andrew J.; Brown, Mary J.; Bonnin, David; Bruford, Elspeth A.; Buhay, Christian; Burch, Paula; Burford, Deborah; Burgess, Joanne; Burrill, Wayne; Burton, John; Bye, Jackie M.; Carder, Carol; Carrel, Laura; Chako, Joseph; Chapman, Joanne C.; Chavez, Dean; Chen, Ellson; Chen, Guan; Chen, Yuan; Chen, Zhijian; Chinault, Craig; Ciccodicola, Alfredo; Clark, Sue Y.; Clarke, Graham; Clee, Chris M.; Clegg, Sheila; Clerc-Blankenburg, Kerstin; Clifford, Karen; Cobley, Vicky; Cole, Charlotte G.; Conquer, Jen S.; Corby, Nicole; Connor, Richard E.; David, Robert; Davies, Joy; Davis, Clay; Davis, John; Delgado, Oliver; DeShazo, Denise; Dhami, Pawandeep; Ding, Yan; Dinh, Huyen; Dodsworth, Steve; Draper, Heather; Dugan-Rocha, Shannon; Dunham, Andrew; Dunn, Matthew; Durbin, K. James; Dutta, Ireena; Eades, Tamsin; Ellwood, Matthew; Emery-Cohen, Alexandra; Errington, Helen; Evans, Kathryn L.; Faulkner, Louisa; Francis, Fiona; Frankland, John; Fraser, Audrey E.; Galgoczy, Petra; Gilbert, James; Gill, Rachel; Glöckner, Gernot; Gregory, Simon G.; Gribble, Susan; Griffiths, Coline; Grocock, Russell; Gu, Yanghong; Gwilliam, Rhian; Hamilton, Cerissa; Hart, Elizabeth A.; Hawes, Alicia; Heath, Paul D.; Heitmann, Katja; Hennig, Steffen; Hernandez, Judith; Hinzmann, Bernd; Ho, Sarah; Hoffs, Michael; Howden, Phillip J.; Huckle, Elizabeth J.; Hume, Jennifer; Hunt, Paul J.; Hunt, Adrienne R.; Isherwood, Judith; Jacob, Leni; Johnson, David; Jones, Sally; de Jong, Pieter J.; Joseph, Shirin S.; Keenan, Stephen; Kelly, Susan; Kershaw, Joanne K.; Khan, Ziad; Kioschis, Petra; Klages, Sven; Knights, Andrew J.; Kosiura, Anna; Kovar-Smith, Christie; Laird, Gavin K.; Langford, Cordelia; Lawlor, Stephanie; Leversha, Margaret; Lewis, Lora; Liu, Wen; Lloyd, Christine; Lloyd, David M.; Loulseged, Hermela; Loveland, Jane E.; Lovell, Jamieson D.; Lozado, Ryan; Lu, Jing; Lyne, Rachael; Ma, Jie; Maheshwari, Manjula; Matthews, Lucy H.; McDowall, Jennifer; McLaren, Stuart; McMurray, Amanda; Meidl, Patrick; Meitinger, Thomas; Milne, Sarah; Miner, George; Mistry, Shailesh L.; Morgan, Margaret; Morris, Sidney; Müller, Ines; Mullikin, James C.; Nguyen, Ngoc; Nordsiek, Gabriele; Nyakatura, Gerald; O’Dell, Christopher N.; Okwuonu, Geoffery; Palmer, Sophie; Pandian, Richard; Parker, David; Parrish, Julia; Pasternak, Shiran; Patel, Dina; Pearce, Alex V.; Pearson, Danita M.; Pelan, Sarah E.; Perez, Lesette; Porter, Keith M.; Ramsey, Yvonne; Reichwald, Kathrin; Rhodes, Susan; Ridler, Kerry A.; Schlessinger, David; Schueler, Mary G.; Sehra, Harminder K.; Shaw-Smith, Charles; Shen, Hua; Sheridan, Elizabeth M.; Shownkeen, Ratna; Skuce, Carl D.; Smith, Michelle L.; Sotheran, Elizabeth C.; Steingruber, Helen E.; Steward, Charles A.; Storey, Roy; Swann, R. Mark; Swarbreck, David; Tabor, Paul E.; Taudien, Stefan; Taylor, Tineace; Teague, Brian; Thomas, Karen; Thorpe, Andrea; Timms, Kirsten; Tracey, Alan; Trevanion, Steve; Tromans, Anthony C.; d’Urso, Michele; Verduzco, Daniel; Villasana, Donna; Waldron, Lenee; Wall, Melanie; Wang, Qiaoyan; Warren, James; Warry, Georgina L.; Wei, Xuehong; West, Anthony; Whitehead, Siobhan L.; Whiteley, Mathew N.; Wilkinson, Jane E.; Willey, David L.; Williams, Gabrielle; Williams, Leanne; Williamson, Angela; Williamson, Helen; Wilming, Laurens; Woodmansey, Rebecca L.; Wray, Paul W.; Yen, Jennifer; Zhang, Jingkun; Zhou, Jianling; Zoghbi, Huda; Zorilla, Sara; Buck, David; Reinhardt, Richard; Poustka, Annemarie; Rosenthal, André; Lehrach, Hans; Meindl, Alfons; Minx, Patrick J.; Hillier, LaDeana W.; Willard, Huntington F.; Wilson, Richard K.; Waterston, Robert H.; Rice, Catherine M.; Vaudin, Mark; Coulson, Alan; Nelson, David L.; Weinstock, George; Sulston, John E.; Durbin, Richard; Hubbard, Tim; Gibbs, Richard A.; Beck, Stephan; Rogers, Jane; Bentley, David R.

2009-01-01

The human X chromosome has a unique biology that was shaped by its evolution as the sex chromosome shared by males and females. We have determined 99.3% of the euchromatic sequence of the X chromosome. Our analysis illustrates the autosomal origin of the mammalian sex chromosomes, the stepwise process that led to the progressive loss of recombination between X and Y, and the extent of subsequent degradation of the Y chromosome. LINE1 repeat elements cover one-third of the X chromosome, with a distribution that is consistent with their proposed role as way stations in the process of X-chromosome inactivation. We found 1,098 genes in the sequence, of which 99 encode proteins expressed in testis and in various tumour types. A disproportionately high number of mendelian diseases are documented for the X chromosome. Of this number, 168 have been explained by mutations in 113 X-linked genes, which in many cases were characterized with the aid of the DNA sequence. PMID:15772651

A novel gene encoding a TIG multiple domain protein is a positional candidate for autosomal recessive polycystic kidney disease.

PubMed

Xiong, Huaqi; Chen, Yongxiong; Yi, Yajun; Tsuchiya, Karen; Moeckel, Gilbert; Cheung, Joseph; Liang, Dan; Tham, Kyi; Xu, Xiaohu; Chen, Xing-Zhen; Pei, York; Zhao, Zhizhuang Jeo; Wu, Guanqing

2002-07-01

Autosomal recessive polycystic kidney disease (ARPKD) is a common hereditary renal cystic disease in infants and children. By genetic linkage analyses, the gene responsible for this disease, termed polycystic kidney and hepatic disease 1 (PKHD1), was mapped on human chromosome 6p21.1-p12, and has been further localized to a 1-cM genetic interval flanked by the D6S1714/D6S243 (telomeric) and D6S1024 (centromeric) markers. We recently identified a novel gene in this genetic interval from kidney cDNA, using cloning strategies. The gene PKHD1 (PKHD1-tentative) encodes a novel 3396-amino-acid protein with no apparent homology with any known proteins. We named its gene product "tigmin" because it contains multiple TIG domains, which usually are seen in proteins containing immunoglobulin-like folds. PKHD1 encodes an 11.6-kb transcript and is composed of 61 exons spanning an approximately 365-kb genomic region on chromosome 6p12-p11.2 adjacent to the marker D6S1714. Northern blot analyses demonstrated that the gene has discrete bands with one peak signal at approximately 11 kb, indicating that PKHD1 is likely to have multiple alternative transcripts. PKHD1 is highly expressed in adult and infant kidneys and weakly expressed in liver in northern blot analysis. This expression pattern parallels the tissue involvement observed in ARPKD. In situ hybridization analysis further revealed that the expression of PKHD1 in the kidney is mainly localized to the epithelial cells of the collecting duct, the specific tubular segment involved in cyst formation in ARPKD. These features of PKHD1 make it a strong positional candidate gene for ARPKD.

A Novel Phytophthora sojae Resistance Rps12 Gene Mapped to a Genomic Region That Contains Several Rps Genes.

PubMed

Sahoo, Dipak K; Abeysekara, Nilwala S; Cianzio, Silvia R; Robertson, Alison E; Bhattacharyya, Madan K

2017-01-01

Phytophthora sojae Kaufmann and Gerdemann, which causes Phytophthora root rot, is a widespread pathogen that limits soybean production worldwide. Development of Phytophthora resistant cultivars carrying Phytophthora resistance Rps genes is a cost-effective approach in controlling this disease. For this mapping study of a novel Rps gene, 290 recombinant inbred lines (RILs) (F7 families) were developed by crossing the P. sojae resistant cultivar PI399036 with the P. sojae susceptible AR2 line, and were phenotyped for responses to a mixture of three P. sojae isolates that overcome most of the known Rps genes. Of these 290 RILs, 130 were homozygous resistant, 12 heterzygous and segregating for Phytophthora resistance, and 148 were recessive homozygous and susceptible. From this population, 59 RILs homozygous for Phytophthora sojae resistance and 61 susceptible to a mixture of P. sojae isolates R17 and Val12-11 or P7074 that overcome resistance encoded by known Rps genes mapped to Chromosome 18 were selected for mapping novel Rps gene. A single gene accounted for the 1:1 segregation of resistance and susceptibility among the RILs. The gene encoding the Phytophthora resistance mapped to a 5.8 cM interval between the SSR markers BARCSOYSSR_18_1840 and Sat_064 located in the lower arm of Chromosome 18. The gene is mapped 2.2 cM proximal to the NBSRps4/6-like sequence that was reported to co-segregate with the Phytophthora resistance genes Rps4 and Rps6. The gene is mapped to a highly recombinogenic, gene-rich genomic region carrying several nucleotide binding site-leucine rich repeat (NBS-LRR)-like genes. We named this novel gene as Rps12, which is expected to be an invaluable resource in breeding soybeans for Phytophthora resistance.

Sequence analysis, identification of evolutionary conserved motifs and expression analysis of murine tcof1 provide further evidence for a potential function for the gene and its human homologue, TCOF1.

PubMed

Dixon, J; Hovanes, K; Shiang, R; Dixon, M J

1997-05-01

The gene mutated in Treacher Collins syndrome, an autosomal dominant disorder of facial development, has recently been cloned. While the function of the predicted protein, Treacle, is unknown, it has been shown to share a number of features with the highly phosphorylated nucleolar phosphoproteins, which play a role in nucleolar-cytoplasmic transport. In the current study, the murine homologue of the Treacher Collins syndrome gene has been isolated and shown to encode a low complexity, serine/alanine-rich protein of 133 kDa. Interspecies comparison indicates that the proteins display 61.5% identity, with the level of conservation being greatest in the regions of acidic/basic amino acid repeats and nuclear localization signals. These features are shared with the nucleolar phosphoproteins. Confirmation that the gene isolated in the current study is orthologous with the Treacher Collins syndrome gene was provided by the demonstration that it mapped to central mouse chromosome 18 in a conserved syntenic region with human chromosome 5q21-q33. Expression analysis in the mouse indicated that the gene was expressed in a wide variety of embryonic and adult tissues. Peak levels of expression in the developing embryo were observed at the edges of the neural folds immediately prior to fusion, and also in the developing branchial arches at the times of critical morphogenetic events. These observations support a role for the gene in the development of the craniofacial complex and provide further evidence that the gene encodes a protein which may be involved in nucleolar-cytoplasmic transport.

Postnatal Survival of Mice with Maternal Duplication of Distal Chromosome 7 Induced by a Igf2/H19 Imprinting Control Region Lacking Insulator Function

PubMed Central

Han, Li; Szabó, Piroska E.; Mann, Jeffrey R.

2010-01-01

The misexpressed imprinted genes causing developmental failure of mouse parthenogenones are poorly defined. To obtain further insight, we investigated misexpressions that could cause the pronounced growth deficiency and death of fetuses with maternal duplication of distal chromosome (Chr) 7 (MatDup.dist7). Their small size could involve inactivity of Igf2, encoding a growth factor, with some contribution by over-expression of Cdkn1c, encoding a negative growth regulator. Mice lacking Igf2 expression are usually viable, and MatDup.dist7 death has been attributed to the misexpression of Cdkn1c or other imprinted genes. To examine the role of misexpressions determined by two maternal copies of the Igf2/H19 imprinting control region (ICR)—a chromatin insulator, we introduced a mutant ICR (ICRΔ) into MatDup.dist7 fetuses. This activated Igf2, with correction of H19 expression and other imprinted transcripts expected. Substantial growth enhancement and full postnatal viability was obtained, demonstrating that the aberrant MatDup.dist7 phenotype is highly dependent on the presence of two unmethylated maternal Igf2/H19 ICRs. Activation of Igf2 is likely the predominant correction that rescued growth and viability. Further experiments involved the introduction of a null allele of Cdkn1c to alleviate its over-expression. Results were not consistent with the possibility that this misexpression alone, or in combination with Igf2 inactivity, mediates MatDup.dist7 death. Rather, a network of misexpressions derived from dist7 is probably involved. Our results are consistent with the idea that reduced expression of IGF2 plays a role in the aetiology of the human imprinting-related growth-deficit disorder, Silver-Russell syndrome. PMID:20062522

Genome-Wide Association Mapping of Flowering and Ripening Periods in Apple

PubMed Central

Urrestarazu, Jorge; Muranty, Hélène; Denancé, Caroline; Leforestier, Diane; Ravon, Elisa; Guyader, Arnaud; Guisnel, Rémi; Feugey, Laurence; Aubourg, Sébastien; Celton, Jean-Marc; Daccord, Nicolas; Dondini, Luca; Gregori, Roberto; Lateur, Marc; Houben, Patrick; Ordidge, Matthew; Paprstein, Frantisek; Sedlak, Jiri; Nybom, Hilde; Garkava-Gustavsson, Larisa; Troggio, Michela; Bianco, Luca; Velasco, Riccardo; Poncet, Charles; Théron, Anthony; Moriya, Shigeki; Bink, Marco C. A. M.; Laurens, François; Tartarini, Stefano; Durel, Charles-Eric

2017-01-01

Deciphering the genetic control of flowering and ripening periods in apple is essential for breeding cultivars adapted to their growing environments. We implemented a large Genome-Wide Association Study (GWAS) at the European level using an association panel of 1,168 different apple genotypes distributed over six locations and phenotyped for these phenological traits. The panel was genotyped at a high-density of SNPs using the Axiom®Apple 480 K SNP array. We ran GWAS with a multi-locus mixed model (MLMM), which handles the putatively confounding effect of significant SNPs elsewhere on the genome. Genomic regions were further investigated to reveal candidate genes responsible for the phenotypic variation. At the whole population level, GWAS retained two SNPs as cofactors on chromosome 9 for flowering period, and six for ripening period (four on chromosome 3, one on chromosome 10 and one on chromosome 16) which, together accounted for 8.9 and 17.2% of the phenotypic variance, respectively. For both traits, SNPs in weak linkage disequilibrium were detected nearby, thus suggesting the existence of allelic heterogeneity. The geographic origins and relationships of apple cultivars accounted for large parts of the phenotypic variation. Variation in genotypic frequency of the SNPs associated with the two traits was connected to the geographic origin of the genotypes (grouped as North+East, West and South Europe), and indicated differential selection in different growing environments. Genes encoding transcription factors containing either NAC or MADS domains were identified as major candidates within the small confidence intervals computed for the associated genomic regions. A strong microsynteny between apple and peach was revealed in all the four confidence interval regions. This study shows how association genetics can unravel the genetic control of important horticultural traits in apple, as well as reduce the confidence intervals of the associated regions identified by linkage mapping approaches. Our findings can be used for the improvement of apple through marker-assisted breeding strategies that take advantage of the accumulating additive effects of the identified SNPs. PMID:29176988

Nucleic acids encoding human trithorax protein

DOEpatents

Evans, Glen A.; Djabali, Malek; Selleri, Licia; Parry, Pauline

2001-01-01

In accordance with the present invention, there is provided an isolated peptide having the characteristics of human trithorax protein (as well as DNA encoding same, antisense DNA derived therefrom and antagonists therefor). The invention peptide is characterized by having a DNA binding domain comprising multiple zinc fingers and at least 40% amino acid identity with respect to the DNA binding domain of Drosophila trithorax protein and at least 70% conserved sequence with respect to the DNA binding domain of Drosophila trithorax protein, and wherein said peptide is encoded by a gene located at chromosome 11 of the human genome at q23. Also provided are methods for the treatment of subject(s) suffering from immunodeficiency, developmental abnormality, inherited disease, or cancer by administering to said subject a therapeutically effective amount of one of the above-described agents (i.e., peptide, antagonist therefor, DNA encoding said peptide or antisense DNA derived therefrom). Also provided is a method for the diagnosis, in a subject, of immunodeficiency, developmental abnormality, inherited disease, or cancer associated with disruption of chromosome 11 at q23.

Proximity within interphase chromosome contributes to the breakpoint distribution in radiation-induced intrachromosomal exchanges

NASA Astrophysics Data System (ADS)

Zhang, Ye; Uhlemeyer, Jimmy; Hada, Megumi; Asaithamby, A.; Chen, David J.; Wu, Honglu

2014-07-01

Previously, we reported that breaks involved in chromosome aberrations were clustered in several regions of chromosome 3 in human mammary epithelial cells after exposures to either low- or high-LET radiation. In particular, breaks in certain regions of the chromosome tended to rejoin with each other to form an intrachromosome exchange event. This study tests the hypothesis that proximity within a single chromosome in interphase cell nuclei contributes to the distribution of radiation-induced chromosome breaks. Chromosome 3 in G1 human mammary epithelial cells was hybridized with the multicolor banding in situ hybridization (mBAND) probes that distinguish the chromosome in six differently colored regions, and the location of these regions was measured with a laser confocal microscope. Results of the study indicated that, on a multi-mega base pair scale of the DNA, the arrangement of chromatin was non-random. Both telomere regions tended to be located towards the exterior of the chromosome domain, whereas the centromere region towards the interior. In addition, the interior of the chromosome domain was preferentially occupied by the p-arm of the chromatin, which is consistent with our previous finding of intrachromosome exchanges involving breaks on the p-arm and in the centromere region of chromosome 3. Other factors, such as the fragile sites in the 3p21 band and gene regulation, may also contribute to the breakpoint distribution in radiation-induced chromosome aberrations.

Proximity Within Interphase Chromosome Contributes to the Breakpoint Distribution in Radiation-Induced Intrachromosomal Exchanges

NASA Technical Reports Server (NTRS)

Zhang, Ye; Uhlemeyer, Jimmy; Hada, Megumi; Asaithamby, A.; Chen, David J.; Wu, Honglu

2015-01-01

Previously, we reported that breaks involved in chromosome aberrations were clustered in several regions of chromosome3 in human mammary epithelial cells after exposures to either low-or high-LET radiation. In particular, breaks in certain regions of the chromosome tended to rejoin with each other to form an intrachromosome exchange event. This study tests the hypothesis that proximity within a single chromosome in interphase cell nuclei contributes to the distribution of radiation-induced chromosome breaks. Chromosome 3 in G1 human mammary epithelial cells was hybridized with the multicolor banding in situ hybridization (mBAND) probes that distinguish the chromosome in six differently colored regions, and the location of these regions was measured with a laser confocal microscope. Results of the study indicated that, on a multi-mega base pair scale of the DNA, the arrangement of chromatin was non-random. Both telomere regions tended to be located towards the exterior of the chromosome domain, whereas the centromere region towards the interior. In addition, the interior of the chromosome domain was preferentially occupied by the p-arm of the chromatin, which is consistent with our previous finding of intrachromosome exchanges involving breaks on the p-arm and in the centromere region of chromosome3. Other factors, such as the fragile sites in the 3p21 band and gene regulation, may also contribute to the breakpoint distribution in radiation-induced chromosome aberrations. Further investigations suggest that the 3D chromosome folding is cell type and culture condition dependent.

Mycobacterium ahvazicum sp. nov., the nineteenth species of the Mycobacterium simiae complex.

PubMed

Bouam, Amar; Heidarieh, Parvin; Shahraki, Abodolrazagh Hashemi; Pourahmad, Fazel; Mirsaeidi, Mehdi; Hashemzadeh, Mohamad; Baptiste, Emeline; Armstrong, Nicholas; Levasseur, Anthony; Robert, Catherine; Drancourt, Michel

2018-03-07

Four slowly growing mycobacteria isolates were isolated from the respiratory tract and soft tissue biopsies collected in four unrelated patients in Iran. Conventional phenotypic tests indicated that these four isolates were identical to Mycobacterium lentiflavum while 16S rRNA gene sequencing yielded a unique sequence separated from that of M. lentiflavum. One representative strain AFP-003 T was characterized as comprising a 6,121,237-bp chromosome (66.24% guanosine-cytosine content) encoding for 5,758 protein-coding genes, 50 tRNA and one complete rRNA operon. A total of 2,876 proteins were found to be associated with the mobilome, including 195 phage proteins. A total of 1,235 proteins were found to be associated with virulence and 96 with toxin/antitoxin systems. The genome of AFP-003 T has the genetic potential to produce secondary metabolites, with 39 genes found to be associated with polyketide synthases and non-ribosomal peptide syntases and 11 genes encoding for bacteriocins. Two regions encoding putative prophages and three OriC regions separated by the dnaA gene were predicted. Strain AFP-003 T genome exhibits 86% average nucleotide identity with Mycobacterium genavense genome. Genetic and genomic data indicate that strain AFP-003 T is representative of a novel Mycobacterium species that we named Mycobacterium ahvazicum, the nineteenth species of the expanding Mycobacterium simiae complex.

Ti plasmid-encoded genes responsible for catabolism of the crown gall opine mannopine by Agrobacterium tumefaciens are homologs of the T-region genes responsible for synthesis of this opine by the plant tumor.

PubMed

Kim, K S; Farrand, S K

1996-06-01

Agrobacterium tumefaciens NT1 harboring pSaB4, which contains the 14-kb BamHI fragment 4 from the octopine/mannityl opine-type Ti plasmid pTi15955, grew well with agropine (AGR) but slowly with mannopine (MOP) as the sole carbon source. When a second plasmid encoding a dedicated transport system for MOP was introduced, these cells grew well with both AGR and MOP. Transposon insertion mutagenesis and subcloning identified a 5.7-kb region of BamHI fragment 4 that encodes functions required for the degradation of MOP. DNA sequence analysis revealed seven putative genes in this region: mocD (moc for mannityl opine catabolism) and mocE, oriented from right to left, and mocRCBAS, oriented from left to right. Significant identities exist at the nucleotide and derived amino acid sequence levels between these moc genes and the mas genes that are responsible for opine biosynthesis in crown gall tumors. MocD is a homolog of Mas2, the anabolic conjugase encoded by mas2'. MocE and MocC are related to the amino half and the carboxyl half, respectively, of Mas1 (MOP reductase), the second enzyme for MOP biosynthesis. These results indicate that the moc and mas genes evolved from a common origin. MocR and MocS are related to each other and to a putative repressor for the AGR degradation system encoded by the rhizogenic plasmid pRiA4. MocB and MocA are homologs of 6-phosphogluconate dehydratase and glucose-6-phosphate dehydrogenase, respectively. Mutations in mocD and mocE, but not mocC, are suppressed by functions encoded by the chromosome or the 450-kb megaplasmid present in many Agrobacterium isolates. We propose that moc genes derived from genes located elsewhere in the bacterial genome and that the tumor-expressed mas genes evolved from the bacterial moc genes.

Ti plasmid-encoded genes responsible for catabolism of the crown gall opine mannopine by Agrobacterium tumefaciens are homologs of the T-region genes responsible for synthesis of this opine by the plant tumor.

PubMed Central

Kim, K S; Farrand, S K

1996-01-01

Agrobacterium tumefaciens NT1 harboring pSaB4, which contains the 14-kb BamHI fragment 4 from the octopine/mannityl opine-type Ti plasmid pTi15955, grew well with agropine (AGR) but slowly with mannopine (MOP) as the sole carbon source. When a second plasmid encoding a dedicated transport system for MOP was introduced, these cells grew well with both AGR and MOP. Transposon insertion mutagenesis and subcloning identified a 5.7-kb region of BamHI fragment 4 that encodes functions required for the degradation of MOP. DNA sequence analysis revealed seven putative genes in this region: mocD (moc for mannityl opine catabolism) and mocE, oriented from right to left, and mocRCBAS, oriented from left to right. Significant identities exist at the nucleotide and derived amino acid sequence levels between these moc genes and the mas genes that are responsible for opine biosynthesis in crown gall tumors. MocD is a homolog of Mas2, the anabolic conjugase encoded by mas2'. MocE and MocC are related to the amino half and the carboxyl half, respectively, of Mas1 (MOP reductase), the second enzyme for MOP biosynthesis. These results indicate that the moc and mas genes evolved from a common origin. MocR and MocS are related to each other and to a putative repressor for the AGR degradation system encoded by the rhizogenic plasmid pRiA4. MocB and MocA are homologs of 6-phosphogluconate dehydratase and glucose-6-phosphate dehydrogenase, respectively. Mutations in mocD and mocE, but not mocC, are suppressed by functions encoded by the chromosome or the 450-kb megaplasmid present in many Agrobacterium isolates. We propose that moc genes derived from genes located elsewhere in the bacterial genome and that the tumor-expressed mas genes evolved from the bacterial moc genes. PMID:8655509

Characterization and Use of Catabolite-Repressed Promoters from Gluconate Genes in Corynebacterium glutamicum†

PubMed Central

Letek, Michal; Valbuena, Noelia; Ramos, Angelina; Ordóñez, Efrén; Gil, José A.; Mateos, Luís M.

2006-01-01

The genes involved in gluconate catabolism (gntP and gntK) in Corynebacterium glutamicum are scattered in the chromosome, and no regulatory genes are apparently associated with them, in contrast with the organization of the gnt operon in Escherichia coli and Bacillus subtilis. In C. glutamicum, gntP and gntK are essential genes when gluconate is the only carbon and energy source. Both genes contain upstream regulatory regions consisting of a typical promoter and a hypothetical cyclic AMP (cAMP) receptor protein (CRP) binding region but lack the expected consensus operator region for binding of the GntR repressor protein. Expression analysis by Northern blotting showed monocistronic transcripts for both genes. The expression of gntP and gntK is not induced by gluconate, and the gnt genes are subject to catabolite repression by sugars, such as glucose, fructose, and sucrose, as was detected by quantitative reverse transcription-PCR (qRT-PCR). Specific analysis of the DNA promoter sequences (PgntK and PgntP) was performed using bifunctional promoter probe vectors containing mel (involved in melanin production) or egfp2 (encoding a green fluorescent protein derivative) as the reporter gene. Using this approach, we obtained results parallel to those from qRT-PCR. An applied example of in vivo gene expression modulation of the divIVA gene in C. glutamicum is shown, corroborating the possible use of the gnt promoters to control gene expression. glxR (which encodes GlxR, the hypothetical CRP protein) was subcloned from the C. glutamicum chromosomal DNA and overexpressed in corynebacteria; we found that the level of gnt expression was slightly decreased compared to that of the control strains. The purified GlxR protein was used in gel shift mobility assays, and a specific interaction of GlxR with sequences present on PgntP and PgntK fragments was detected only in the presence of cAMP. PMID:16385030

Characterization and use of catabolite-repressed promoters from gluconate genes in Corynebacterium glutamicum.

PubMed

Letek, Michal; Valbuena, Noelia; Ramos, Angelina; Ordóñez, Efrén; Gil, José A; Mateos, Luís M

2006-01-01

The genes involved in gluconate catabolism (gntP and gntK) in Corynebacterium glutamicum are scattered in the chromosome, and no regulatory genes are apparently associated with them, in contrast with the organization of the gnt operon in Escherichia coli and Bacillus subtilis. In C. glutamicum, gntP and gntK are essential genes when gluconate is the only carbon and energy source. Both genes contain upstream regulatory regions consisting of a typical promoter and a hypothetical cyclic AMP (cAMP) receptor protein (CRP) binding region but lack the expected consensus operator region for binding of the GntR repressor protein. Expression analysis by Northern blotting showed monocistronic transcripts for both genes. The expression of gntP and gntK is not induced by gluconate, and the gnt genes are subject to catabolite repression by sugars, such as glucose, fructose, and sucrose, as was detected by quantitative reverse transcription-PCR (qRT-PCR). Specific analysis of the DNA promoter sequences (PgntK and PgntP) was performed using bifunctional promoter probe vectors containing mel (involved in melanin production) or egfp2 (encoding a green fluorescent protein derivative) as the reporter gene. Using this approach, we obtained results parallel to those from qRT-PCR. An applied example of in vivo gene expression modulation of the divIVA gene in C. glutamicum is shown, corroborating the possible use of the gnt promoters to control gene expression. glxR (which encodes GlxR, the hypothetical CRP protein) was subcloned from the C. glutamicum chromosomal DNA and overexpressed in corynebacteria; we found that the level of gnt expression was slightly decreased compared to that of the control strains. The purified GlxR protein was used in gel shift mobility assays, and a specific interaction of GlxR with sequences present on PgntP and PgntK fragments was detected only in the presence of cAMP.

Brief review of the chicken Major Histocompatibility Complex: the genes, their distribution on chromosome 16, and their contributions to disease resistance

PubMed Central

Miller, Marcia M.; Taylor, Robert L.

2016-01-01

Nearly all genes presently mapped to chicken chromosome 16 (GGA 16) have either a demonstrated role in immune responses or are considered to serve in immunity by reason of sequence homology with immune system genes defined in other species. The genes are best described in regional units. Among these, the best known is the polymorphic major histocompatibility complex-B (MHC-B) region containing genes for classical peptide antigen presentation. Nearby MHC-B is a small region containing two CD1 genes, which encode molecules known to bind lipid antigens and which will likely be found in chickens to present lipids to specialized T cells, as occurs with CD1 molecules in other species. Another region is the MHC-Y region, separated from MHC-B by an intervening region of tandem repeats. Like MHC-B, MHC-Y is polymorphic. It contains specialized class I and class II genes and c-type lectin-like genes. Yet another region, separated from MHC-Y by the single nucleolar organizing region (NOR) in the chicken genome, contains olfactory receptor genes and scavenger receptor genes, which are also thought to contribute to immunity. The structure, distribution, linkages and patterns of polymorphism in these regions, suggest GGA 16 evolves as a microchromosome devoted to immune defense. Many GGA 16 genes are polymorphic and polygenic. At the moment most disease associations are at the haplotype level. Roles of individual MHC genes in disease resistance are documented in only a very few instances. Provided suitable experimental stocks persist, the availability of increasingly detailed maps of GGA 16 genes combined with new means for detecting genetic variability will lead to investigations defining the contributions of individual loci and more applications for immunogenetics in breeding healthy poultry. PMID:26740135

Cloning and Expression Pattern of a Gene Encoding an α-Xylosidase Active against Xyloglucan Oligosaccharides from Arabidopsis1

PubMed Central

Sampedro, Javier; Sieiro, Carmen; Revilla, Gloria; González-Villa, Tomás; Zarra, Ignacio

2001-01-01

An α-xylosidase active against xyloglucan oligosaccharides was purified from cabbage (Brassica oleracea var. capitata) leaves. Two peptide sequences were obtained from this protein, the N-terminal and an internal one, and these were used to identify an Arabidopsis gene coding for an α-xylosidase that we propose to call AtXYL1. It has been mapped to a region of chromosome I between markers at 100.44 and 107.48 cM. AtXYL1 comprised three exons and encoded a peptide that was 915 amino acids long, with a potential signal peptide of 22 amino acids and eight possible N-glycosylation sites. The protein encoded by AtXYL1 showed the signature regions of family 31 glycosyl hydrolases, which comprises not only α-xylosidases, but also α-glucosidases. The α-xylosidase activity is present in apoplastic extractions from Arabidopsis seedlings, as suggested by the deduced signal peptide. The first eight leaves from Arabidopsis plants were harvested to analyze α-xylosidase activity and AtXYL1 expression levels. Both increased from older to younger leaves, where xyloglucan turnover is expected to be higher. When this gene was introduced in a suitable expression vector and used to transform Saccharomyces cerevisiae, significantly higher α-xylosidase activity was detected in the yeast cells. α-Glucosidase activity was also increased in the transformed cells, although to a lesser extent. These results show that AtXYL1 encodes for an apoplastic α-xylosidase active against xyloglucan oligosaccharides that probably also has activity against p-nitrophenyl-α-d-glucoside. PMID:11402218

Cloning and expression pattern of a gene encoding an alpha-xylosidase active against xyloglucan oligosaccharides from Arabidopsis.

PubMed

Sampedro, J; Sieiro, C; Revilla, G; González-Villa, T; Zarra, I

2001-06-01

An alpha-xylosidase active against xyloglucan oligosaccharides was purified from cabbage (Brassica oleracea var. capitata) leaves. Two peptide sequences were obtained from this protein, the N-terminal and an internal one, and these were used to identify an Arabidopsis gene coding for an alpha-xylosidase that we propose to call AtXYL1. It has been mapped to a region of chromosome I between markers at 100.44 and 107.48 cM. AtXYL1 comprised three exons and encoded a peptide that was 915 amino acids long, with a potential signal peptide of 22 amino acids and eight possible N-glycosylation sites. The protein encoded by AtXYL1 showed the signature regions of family 31 glycosyl hydrolases, which comprises not only alpha-xylosidases, but also alpha-glucosidases. The alpha-xylosidase activity is present in apoplastic extractions from Arabidopsis seedlings, as suggested by the deduced signal peptide. The first eight leaves from Arabidopsis plants were harvested to analyze alpha-xylosidase activity and AtXYL1 expression levels. Both increased from older to younger leaves, where xyloglucan turnover is expected to be higher. When this gene was introduced in a suitable expression vector and used to transform Saccharomyces cerevisiae, significantly higher alpha-xylosidase activity was detected in the yeast cells. alpha-Glucosidase activity was also increased in the transformed cells, although to a lesser extent. These results show that AtXYL1 encodes for an apoplastic alpha-xylosidase active against xyloglucan oligosaccharides that probably also has activity against p-nitrophenyl-alpha-D-glucoside.

Homozygosity Mapping Identifies an Additional Locus for Wolfram Syndrome on Chromosome 4q

PubMed Central

El-Shanti, Hatem; Lidral, Andrew C.; Jarrah, Nadim; Druhan, Lawrence; Ajlouni, Kamel

2000-01-01

Wolfram syndrome, which is sometimes referred to as “DIDMOAD” (diabetes insipidus, diabetes mellitus, optic atrophy, and deafness), is an autosomal recessive neurodegenerative disorder for which only insulin-dependent diabetes mellitus and optic atrophy are necessary to make the diagnosis. Researchers have mapped Wolfram syndrome to chromosome 4p16.1, and, recently, a gene encoding a putative transmembrane protein has been cloned and mutations have been identified in patients. To pursue the possibility of locus heterogeneity, 16 patients from four different families were recruited. These patients, who have the Wolfram syndrome phenotype, also have additional features that have not previously been reported. There is an absence of diabetes insipidus in all affected family members. In addition, several patients have profound upper gastrointestinal ulceration and bleeding. With the use of three microsatellite markers (D4S432, D4S3023, and D4S2366) reported to be linked to the chromosome 4p16.1 locus, we significantly excluded linkage in three of the four families. The two affected individuals in one family showed homozygosity for all three markers from the region of linkage on chromosome 4p16.1. For the other three families, genetic heterogeneity for Wolfram syndrome was verified by demonstration of linkage to chromosome 4q22-24. In conclusion, we report the unique clinical findings and linkage-analysis results of 16 patients with Wolfram syndrome and provide further evidence for the genetic heterogeneity of this disorder. We also provide data on a new locus that plays a role in the etiology of insulin-dependent diabetes mellitus. PMID:10739754

Characterization and chromosomal mapping of the human TFG gene involved in thyroid carcinoma

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

Mencinger, M.; Panagopoulos, I.; Andreasson, P.

1997-05-01

Homology searches in the Expressed Sequence Tag Database were performed using SPYGQ-rich regions as query sequences to find genes encoding protein regions similar to the N-terminal parts of the sarcoma-associated EWS and FUS proteins. Clone 22911 (T74973), encoding a SPYGQ-rich region in its 5{prime} end, and several other clones that overlapped 22911 were selected. The combined data made it possible to assemble a full-length cDNA sequence. This cDNA sequence is 1677 bp, containing an initiation codon ATG, an open reading frame of 400 amino acids, a poly(A) signal, and a poly(A) tail. We found 100% identity between the 5{prime} partmore » of the consensus sequence and the 598-bp-long sequence named TFG. The TFG sequence is fused to the 3{prime} end of NTRK1, generating the TRK-T3 fusion transcript found in papillary thyroid carcinoma. The cDNA therefore represents the full-length transcript of the TFG gene. TFG was localized to 3q11-q12 by fluorescence in situ hybridization. The 3{prime} and the 5{prime} ends of the TFG cDNA probe hybridized to a 2.2-kb band on Northern blot filters in all tissues examined. 28 refs., 5 figs., 1 tab.« less

CHST6 mutations in North American subjects with macular corneal dystrophy: a comprehensive molecular genetic review.

PubMed

Klintworth, Gordon K; Smith, Clayton F; Bowling, Brandy L

2006-03-10

To evaluate mutations in the carbohydrate sulfotransferase-6 (CHST6) gene in American subjects with macular corneal dystrophy (MCD). We analyzed CHST6 in 57 patients from 31 families with MCD from the United States, 57 carriers (parents or children), and 27 unaffected blood relatives of affected subjects. We compared the observed nucleotide sequences with those found by numerous investigators in other populations with MCD and in controls. In 24 families, the corneal disorder could be explained by mutations in the coding region of CHST6 or in the region upstream of this gene in both the maternal and paternal chromosome. In most instances of MCD a homozygous or heterozygous missense mutation in exon 3 of CHST6 was found. Six cases resulted from a deletion upstream of CHST6. Nucleotide changes within the coding region of CHST6 are predicted to alter the encoded protein significantly within evolutionary conserved parts of the encoded sulfotransferase. Our findings support the hypothesis that CHST6 mutations are cardinal to the pathogenesis of MCD. Moreover, the observation that some cases of MCD cannot be explained by mutations in CHST6 suggests that MCD may result from other subtle changes in CHST6 or from genetic heterogeneity.

Localisation of the gene for cylindromatosis (turban tumor syndrome) to chromosome 9p12-13

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

Wooster, R.; Mangion, J.; Quirk, Y.

Cylindromatosis (multiple cylindromas, tomato syndrome syndrome, turban tumor syndrome) is a rare autosomal dominant disease characterized by the development of multiple, slow growing neoplasms of the skin appendages. The tumors, known as dermal cylindromas, exhibit histological features of eccrine or apocrine sweat glands and occur most commonly in the scalp area. Genetic linkage analysis of two families yielded a maximum two point LOD score of 3.2 at D9S169. Critical recombinants place the gene between D9S161 and IFN, a distance of approximately 9 cM. This region of chromosome 9 harbors a gene that encodes a 16 kD protein which is anmore » inhibitor of cyclin dependent kinase 4 (CDK-4) and which is somatically mutated in many classes of cancer. However, the observation of recombinants between the disease and a polymorphic microsatellite repeat CT29 close to this gene, suggests that the CDK-4 inhibitor gene is unlikely to be responsible for cylindromatosis.« less

The X chromosome of monotremes shares a highly conserved region with the eutherian and marsupial X chromosomes despite the absence of X chromosome inactivation

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

Watson, J.M.; Spencer, J.A.; Graves, J.A.M.

1990-09-01

Eight genes, located on the long arm of the human X chromosome and present on the marsupial X chromosome, were mapped by in situ hybridization to the chromosomes of the platypus Ornithorhynchus anatinus, one of the three species of monotreme mammals. All were located on the X chromosome. The authors conclude that the long arm of the human X chromosome represents a highly conserved region that formed part of the X chromosome in a mammalian ancestor at least 150 million years ago. Since three of these genes are located on the long arm of the platypus X chromosome, which ismore » G-band homologous to the Y chromosome and apparently exempt from X chromosome inactivation, the conservation of this region has evidently not depended on isolation by X-Y chromosome differentiation and X chromosome inactivation.« less

Plasma amine oxidase activities in Norrie disease patients with an X-chromosomal deletion affecting monoamine oxidase.

PubMed

Murphy, D L; Sims, K B; Karoum, F; Garrick, N A; de la Chapelle, A; Sankila, E M; Norio, R; Breakefield, X O

1991-01-01

Two individuals with an X-chromosomal deletion were recently found to lack the genes encoding monoamine oxidase type A (MAO-A) and MAO-B. This abnormality was associated with almost total (90%) reductions in the oxidatively deaminated urinary metabolites of the MAO-A substrate, norepinephrine, and with marked (100-fold) increases in an MAO-B substrate, phenylethylamine, confirming systemic functional consequences of the genetic enzyme deficiency. However, urinary concentrations of the deaminated metabolites of dopamine and serotonin (5-HT) were essentially normal. To investigate other deaminating systems besides MAO-A and MAO-B that might produce these metabolites of dopamine and 5-HT, we examined plasma amine oxidase (AO) activity in these two patients and two additional patients with the same X-chromosomal deletion. Normal plasma AO activity was found in all four Norrie disease-deletion patients, in four patients with classic Norrie disease without a chromosomal deletion, and in family members of patients from both groups. Marked plasma amine metabolite abnormalities and essentially absent platelet MAO-B activity were found in all four Norrie disease-deletion patients, but in none of the other subjects in the two comparison groups. These results indicate that plasma AO is encoded by gene(s) independent of those for MAO-A and MAO-B, and raise the possibility that plasma AO, and perhaps the closely related tissue AO, benzylamine oxidase, as well as other atypical AOs or MAOs encoded independently from MAO-A and MAO-B may contribute to the oxidative deamination of dopamine and 5-HT in humans.

The genome sequence of the facultative intracellular pathogen Brucella melitensis.

PubMed

DelVecchio, Vito G; Kapatral, Vinayak; Redkar, Rajendra J; Patra, Guy; Mujer, Cesar; Los, Tamara; Ivanova, Natalia; Anderson, Iain; Bhattacharyya, Anamitra; Lykidis, Athanasios; Reznik, Gary; Jablonski, Lynn; Larsen, Niels; D'Souza, Mark; Bernal, Axel; Mazur, Mikhail; Goltsman, Eugene; Selkov, Eugene; Elzer, Philip H; Hagius, Sue; O'Callaghan, David; Letesson, Jean-Jacques; Haselkorn, Robert; Kyrpides, Nikos; Overbeek, Ross

2002-01-08

Brucella melitensis is a facultative intracellular bacterial pathogen that causes abortion in goats and sheep and Malta fever in humans. The genome of B. melitensis strain 16M was sequenced and found to contain 3,294,935 bp distributed over two circular chromosomes of 2,117,144 bp and 1,177,787 bp encoding 3,197 ORFs. By using the bioinformatics suite ERGO, 2,487 (78%) ORFs were assigned functions. The origins of replication of the two chromosomes are similar to those of other alpha-proteobacteria. Housekeeping genes, including those involved in DNA replication, transcription, translation, core metabolism, and cell wall biosynthesis, are distributed on both chromosomes. Type I, II, and III secretion systems are absent, but genes encoding sec-dependent, sec-independent, and flagella-specific type III, type IV, and type V secretion systems as well as adhesins, invasins, and hemolysins were identified. Several features of the B. melitensis genome are similar to those of the symbiotic Sinorhizobium meliloti.

The genome sequence of the facultative intracellular pathogen Brucella melitensis

PubMed Central

DelVecchio, Vito G.; Kapatral, Vinayak; Redkar, Rajendra J.; Patra, Guy; Mujer, Cesar; Los, Tamara; Ivanova, Natalia; Anderson, Iain; Bhattacharyya, Anamitra; Lykidis, Athanasios; Reznik, Gary; Jablonski, Lynn; Larsen, Niels; D'Souza, Mark; Bernal, Axel; Mazur, Mikhail; Goltsman, Eugene; Selkov, Eugene; Elzer, Philip H.; Hagius, Sue; O'Callaghan, David; Letesson, Jean-Jacques; Haselkorn, Robert; Kyrpides, Nikos; Overbeek, Ross

2002-01-01

Brucella melitensis is a facultative intracellular bacterial pathogen that causes abortion in goats and sheep and Malta fever in humans. The genome of B. melitensis strain 16M was sequenced and found to contain 3,294,935 bp distributed over two circular chromosomes of 2,117,144 bp and 1,177,787 bp encoding 3,197 ORFs. By using the bioinformatics suite ERGO, 2,487 (78%) ORFs were assigned functions. The origins of replication of the two chromosomes are similar to those of other α-proteobacteria. Housekeeping genes, including those involved in DNA replication, transcription, translation, core metabolism, and cell wall biosynthesis, are distributed on both chromosomes. Type I, II, and III secretion systems are absent, but genes encoding sec-dependent, sec-independent, and flagella-specific type III, type IV, and type V secretion systems as well as adhesins, invasins, and hemolysins were identified. Several features of the B. melitensis genome are similar to those of the symbiotic Sinorhizobium meliloti. PMID:11756688

Bioinformatics Analysis of NBS-LRR Encoding Resistance Genes in Setaria italica.

PubMed

Zhao, Yan; Weng, Qiaoyun; Song, Jinhui; Ma, Hailian; Yuan, Jincheng; Dong, Zhiping; Liu, Yinghui

2016-06-01

In plants, resistance (R) genes are involved in pathogen recognition and subsequent activation of innate immune responses. The nucleotide-binding site-leucine-rich repeat (NBS-LRR) genes family forms the largest R-gene family among plant genomes and play an important role in plant disease resistance. In this paper, comprehensive analysis of NBS-encoding genes is performed in the whole Setaria italica genome. A total of 96 NBS-LRR genes are identified, and comprehensive overview of the NBS-LRR genes is undertaken, including phylogenetic analysis, chromosome locations, conserved motifs of proteins, and gene expression. Based on the domain, these genes are divided into two groups and distributed in all Setaria italica chromosomes. Most NBS-LRR genes are located at the distal tip of the long arms of the chromosomes. Setaria italica NBS-LRR proteins share at least one nucleotide-biding domain and one leucine-rich repeat domain. Our results also show the duplication of NBS-LRR genes in Setaria italica is related to their gene structure.

Polymorphism in and localization of the gene LCP2 (SLP-76) to chromosome 5q33.1-qter

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

Sunden, S.L.F.; Carr, L.L.; Clements, J.L.

This report describes the localization of the human LCP2 gene to human chromosome 5q33.1-qter using single-stranded conformation polymorphisms analysis. This gene encodes an SH2 domain containing leukocyte protein of 76 kDa (SLP-76), which plays a functional role in T-cell activation. It remains to be determined whether mutations in this gene or translocations at this chromosome location are the genetic basis for various diseases, including lymphoblastic leukemia. 12 refs., 1 fig.

HIM-8 binds to the X chromosome pairing center and mediates chromosome-specific meiotic synapsis.

PubMed

Phillips, Carolyn M; Wong, Chihunt; Bhalla, Needhi; Carlton, Peter M; Weiser, Pinky; Meneely, Philip M; Dernburg, Abby F

2005-12-16

The him-8 gene is essential for proper meiotic segregation of the X chromosomes in C. elegans. Here we show that loss of him-8 function causes profound X chromosome-specific defects in homolog pairing and synapsis. him-8 encodes a C2H2 zinc-finger protein that is expressed during meiosis and concentrates at a site on the X chromosome known as the meiotic pairing center (PC). A role for HIM-8 in PC function is supported by genetic interactions between PC lesions and him-8 mutations. HIM-8 bound chromosome sites associate with the nuclear envelope (NE) throughout meiotic prophase. Surprisingly, a point mutation in him-8 that retains both chromosome binding and NE localization fails to stabilize pairing or promote synapsis. These observations indicate that stabilization of homolog pairing is an active process in which the tethering of chromosome sites to the NE may be necessary but is not sufficient.

Correlation Between Interphase Chromatin Structure and - and High-Let Radiation-Induced - and Intra-Chromosome Exchange Hotspots

NASA Astrophysics Data System (ADS)

Zhang, Ye; Wu, Honglu; Mangala, Lingegowda; Asaithamby, Aroumougame; Chen, David

2012-07-01

CORRELATION BETWEEN INTERPHASE CHROMATIN STRUCTURE AND LOW- AND HIGH-LET RADIATION-INDUCED INTER- AND INTRA-CHROMOSOME EXCHANGE HOTSPOTS Ye Zhang1,2, Lingegowda S. Mangala1,3, Aroumougame Asaithamby4, David J. Chen4, and Honglu Wu1 1 NASA Johnson Space Center, Houston, Texas, USA 2 Wyle Integrated Science and Engineering Group, Houston, Texas, USA 3 University of Houston Clear Lake, Houston, Texas, USA 4 University of Texas, Southwestern Medical Center, Dallas, Texas, USA To investigate the relationship between chromosome aberrations induced by low- and high-LET radiation and chromatin folding, we reconstructed the three dimensional structure of chromosome 3 and measured the physical distances between different regions of this chromosome. Previously, we investigated the location of breaks involved in inter- and intrachromosomal type exchange events in chromosome 3 of human epithelial cells, using the multicolor banding in situ hybridization (mBAND) technique. After exposure to both low- and high-LET radiations in vitro, intra-chromosome exchanges occurred preferentially between a break in the 3p21 and one in the 3q11 regions, and the breaks involved in inter-chromosome exchanges occurred in two regions near the telomeres of the chromosome. In this study, human epithelial cells were fixed in G1 phase and interphase chromosomes hybridized with an mBAND probe for chromosome 3 were captured with a laser scanning confocal microscope. The 3-dimensional structure of interphase chromosome 3 with different colored regions was reconstructed, and the distance between different regions was measured. We show that, in most of the G1 cells, the regions containing 3p21 and 3q11 are colocalized in the center of the chromosome domain, whereas, the regions towards the telomeres of the chromosome are located in the peripherals of the chromosome domain. Our results demonstrate that the distribution of breaks involved in radiation-induced inter and intra-chromosome aberrations depends upon both the location of fragile sites and the folding of chromatins.

Isolation of a transcription factor expressed in neural crest from the region of 22q11 deleted in DiGeorge syndrome

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

Wadey, R.; Roberts, C.; Daw, S.

1994-09-01

Deletions within chromosome 22q11 cause a wide variety of birth defects including DiGeorge syndrome and Shprintzen syndrome. We have defined a commonly deleted region of over 2 Mb, and a critical region of 300 kb. A gene, TUPLE1, has been isolated from this critical region encoding a transcriptional regulator similar to the yeast HIR1 histone regulator gene. Since it has been suggested that DGS results from a defective neural crest, the expression of Tuple1 was examined in whole mouse and chick embryos, tissue sections and neural tube explants: Tuple1 is expressed in a dynamic pattern with high levels in regionsmore » containing migrating crest. Prior to crest migration Tuple1 is expressed in a rhombomere-specific expression pattern. Later Tuple1 is expressed in discrete domains within the developing neural tube. A remarkable feature of the experiments was the detection of a similar dynamic pattern with sense probe; i.e., there is an antisense Tuple1 transcript. This was confirmed using RPA. Tuple1 is being screened for mutations in non-deletion patients and constructs assembled for homologous recombination in ES cells. Tuple1 maps to MMU16 extending the homology of linkage with human chromosome 22. From these data we predict that the human homologue of the murine scid mutation maps to 22q11.« less

Analysis of sequence variation among smeDEF multi drug efflux pump genes and flanking DNA from defined 16S rRNA subgroups of clinical Stenotrophomonas maltophilia isolates.

PubMed

Gould, Virginia C; Okazaki, Aki; Howe, Robin A; Avison, Matthew B

2004-08-01

To determine the level of variation in the smeDEF efflux pump and smeT transcriptional regulator genes among three defined 16S rRNA sequence subgroups of clinical Stenotrophomonas maltophilia isolates. smeDEF sequencing used a PCR genome walking approach. Determination of the sequence surrounding smeDEF used a flanking primer PCR method and specific primers anchored in smeD or smeF together with random primers. smeDEF is chromosomal and located in the same position in the chromosome in all three subgroups of isolates. Flanking smeD is a gene, smeT, encoding a putative transcriptional repressor for smeDEF. Variation at these loci among the isolates is considerably lower (up to 10%) than at intrinsic beta-lactamase loci (up to 30%) in the same isolates, implying greater functional constraint. The smeD-smeT intergenic region contains a highly conserved section, which maps with previously predicted promoter/operator regions, and a hypervariable untranslated region, which can be used to subgroup clinical isolates. These data provide further evidence that it is possible to group clinical isolates of the inherently variable species, S. maltophilia, based on genotypic properties. Isolate D457, in which most work concerning smeDEF expression has been performed, does not fall into S. maltophilia subgroup A, which is the most typical.

Complete sequence of Tvv1, a family of Ty 1 copia-like retrotransposons of Vitis vinifera L., reconstituted by chromosome walking.

PubMed

Pelsy, F.; Merdinoglu, D.

2002-09-01

A chromosome-walking strategy was used to sequence and characterize retrotransposons in the grapevine genome. The reconstitution of a family of retroelements, named Tvv1, was achieved by six successive steps. These elements share a single, highly conserved open reading frame 4,153 nucleotides-long, putatively encoding the gag, pro, int, rt and rh proteins. Comparison of the Tvv1 open reading frame coding potential with those of drosophila copia and tobacco Tnt1, revealed that Tvv1 is closely related to Ty 1 copia-like retrotransposons. A highly variable untranslated leader region, upstream of the open reading frame, allowed us to differentiate Tvv1 variants, which represent a family of at least 28 copies, in varying sizes. This internal region is flanked by two long terminal repeats in direct orientation, sized between 149 and 157 bp. Among elements theoretically sized from 4,970 to 5,550 bp, we describe the full-length sequence of a reference element Tvv1-1, 5,343 nucleotides-long. The full-length sequence of Tvv1-1 compared to pea PDR1 shows a 53.3% identity. In addition, both elements contain long terminal repeats of nearly the same size in which the U5 region could be entirely absent. Therefore, we assume that Tvv1 and PDR1 could constitute a particular class of short LTRs retroelements.

Deregulation of the telomerase reverse transcriptase (TERT) gene by chromosomal translocations in B-cell malignancies.

PubMed

Nagel, Inga; Szczepanowski, Monika; Martín-Subero, José I; Harder, Lana; Akasaka, Takashi; Ammerpohl, Ole; Callet-Bauchu, Evelyne; Gascoyne, Randy D; Gesk, Stefan; Horsman, Doug; Klapper, Wolfram; Majid, Aneela; Martinez-Climent, José A; Stilgenbauer, Stephan; Tönnies, Holger; Dyer, Martin J S; Siebert, Reiner

2010-08-26

Sequence variants at the TERT-CLPTM1L locus in chromosome 5p have been recently associated with disposition for various cancers. Here we show that this locus including the gene encoding the telomerase reverse-transcriptase TERT at 5p13.33 is rarely but recurrently targeted by somatic chromosomal translocations to IGH and non-IG loci in B-cell neoplasms, including acute lymphoblastic leukemia, chronic lymphocytic leukemia, mantle cell lymphoma and splenic marginal zone lymphoma. In addition, cases with genomic amplification of TERT locus were identified. Tumors bearing chromosomal aberrations involving TERT showed higher TERT transcriptional expression and increased telomerase activity. These data suggest that deregulation of TERT gene by chromosomal abnormalities leading to increased telomerase activity might contribute to B-cell lymphomagenesis.

The Correlation of Interphase Chromatin Structure with the Radiation-Induced Inter- and Intrachromosome Exchange Hotspots

NASA Technical Reports Server (NTRS)

Zhang, Ye; Mangala, Lingegowda S.; Purgason, Ashley M.; Hada, Megumi; Cucinotta, Francis A.; Wu, Honglu

2011-01-01

To investigate the relationship between chromosome aberrations induced by radiation and chromatin folding, we reconstructed three dimensional structure of chromosome 3 and measured the physical distances between different regions of the chromosome. Previously, we have investigated the location of breaks involved in inter- and intrachromosomal type exchange events in human chromosome 3, using the multicolor banding in situ hybridization (mBAND) technique. In human epithelial cells exposed to both low- and high-LET radiations in vitro, we reported that intra-chromosome exchanges occurred preferentially between a break in the 3p21 and one in the 3q11 regions, and the breaks involving in inter-chromosome exchanges occurred in two regions towards the telomeres of the chromosome. Exchanges were also observed between a break in 3p21 and one in 3q26, but few exchanges were observed between breaks in 3q11 and 3q26, even though the two regions are located on the same arm of the chromosome. In this study, human epithelial cells were fixed at G1 phase and the interphase cells were hybridized using the XCyte3 mBAND kit from MetaSystems. The z-section images of chromosome 3 were captured with a Leica and an LSM 510 Meta laser scanning confocal microscopes. A total of 100 chromosomes were analyzed. The reconstruction of three dimensional structure of interphase chromosome 3 with six different colored regions was achieved using the Imaris software. The relative distance between different regions was measured as well. We further analyzed fragile sites on the chromosome that have been identified in various types of cancers. The data showed that, in majority of the cells, the regions containing 3p21 and 3q11 are colocalized in the center of the chromosome, whereas, the regions towards the telomeres of the chromosome are either physically wrapping outside the chromosome center or with arms sticking out. Our results demonstrated that the distribution of breaks involved in radiation-induced inter and intra-chromosome aberrations depends upon both the location of fragile sites and the folding of chromatins.

Mapping of the Tuple1 gene to mouse chromosome 16A-B1

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

Mattei, M.G.; Halford, S.; Scambler, P.J.

The human TUPLE1 gene encodes a putative transcriptional regulator and maps to chromosome 22, and therefore may play a role in Di-George syndrome (DGS), relo-cardio-facial syndrome (VCFS), or a related pathology. The murine TUPLE1 gene has also been cloned and shows strong sequence similarity to TUPLE1. Comparative mapping is useful in the study of chromosome evolution and is sometimes able to indicate possible mouse mutations that are potential models of human genetic disorders. As TIPLE1 is a candidate gene for the haploinsufficient phenotype in DGS, we mapped TUPLE1 to mouse chromosome 16A-B1. 6 refs., 1 fig.

A Genetic Association Study of Chromosome 11q22-24 in Two Different Samples Implicates the FXYD6 Gene, Encoding Phosphohippolin, in Susceptibility to Schizophrenia

PubMed Central

Choudhury, Khalid; McQuillin, Andrew; Puri, Vinay; Pimm, Jonathan; Datta, Susmita; Thirumalai, Srinivasa; Krasucki, Robert; Lawrence, Jacob; Bass, Nicholas J.; Quested, Digby; Crombie, Caroline; Fraser, Gillian; Walker, Nicholas; Nadeem, Haitham; Johnson, Sophie; Curtis, David; St. Clair, David; Gurling, Hugh M. D.

2007-01-01

Previous linkage analyses of families with multiple cases of schizophrenia by us and others have confirmed the involvement of the chromosome 11q22-24 region in the etiology of schizophrenia, with LOD scores of 3.4 and 3.1. We now report fine mapping of a susceptibility gene in the 11q22-24 region, determined on the basis of a University College London (UCL) sample of 496 cases and 488 supernormal controls. Confirmation was then performed by the study of an Aberdeen sample consisting of 858 cases and 591 controls (for a total of 2,433 individuals: 1,354 with schizophrenia and 1,079 controls). Seven microsatellite or single-nucleotide polymorphism (SNP) markers localized within or near the FXYD6 gene showed empirically significant allelic associations with schizophrenia in the UCL sample (for D11S1998, P=.021; for rs3168238, P=.009; for TTTC20.2, P=.048; for rs1815774, P=.049; for rs4938445, P=.010; for rs4938446, P=.025; for rs497768, P=.023). Several haplotypes were also found to be associated with schizophrenia; for example, haplotype Hap-F21 comprising markers rs10790212-rs4938445-rs497768 was found to be associated with schizophrenia, by a global permutation test (P=.002). Positive markers in the UCL sample were then genotyped in the Aberdeen sample. Two of these SNPs were found to be associated with schizophrenia in the Scottish sample (for rs4938445, P=.044; for rs497768, P=.037). The Hap-F21 haplotype also showed significant association with schizophrenia in the Aberdeen sample, with the same alleles being associated (P=.013). The FXYD6 gene encodes a protein called “phosphohippolin” that is highly expressed in regions of the brain thought to be involved in schizophrenia. The protein functions by modulating the kinetic properties of Na,K-ATPase to the specific physiological requirements of the tissue. Etiological base-pair changes in FXYD6 or in associated promoter/control regions are likely to cause abnormal function or expression of phosphohippolin and to increase genetic susceptibility to schizophrenia. PMID:17357072

Isolation and characterization of a cDNA clone for the complete protein coding region of the delta subunit of the mouse acetylcholine receptor.

PubMed Central

LaPolla, R J; Mayne, K M; Davidson, N

1984-01-01

A mouse cDNA clone has been isolated that contains the complete coding region of a protein highly homologous to the delta subunit of the Torpedo acetylcholine receptor (AcChoR). The cDNA library was constructed in the vector lambda 10 from membrane-associated poly(A)+ RNA from BC3H-1 mouse cells. Surprisingly, the delta clone was selected by hybridization with cDNA encoding the gamma subunit of the Torpedo AcChoR. The nucleotide sequence of the mouse cDNA clone contains an open reading frame of 520 amino acids. This amino acid sequence exhibits 59% and 50% sequence homology to the Torpedo AcChoR delta and gamma subunits, respectively. However, the mouse nucleotide sequence has several stretches of high homology with the Torpedo gamma subunit cDNA, but not with delta. The mouse protein has the same general structural features as do the Torpedo subunits. It is encoded by a 3.3-kilobase mRNA. There is probably only one, but at most two, chromosomal genes coding for this or closely related sequences. Images PMID:6096870

Process of labeling specific chromosomes using recombinant repetitive DNA

DOEpatents

Moyzis, R.K.; Meyne, J.

1988-02-12

Chromosome preferential nucleotide sequences are first determined from a library of recombinant DNA clones having families of repetitive sequences. Library clones are identified with a low homology with a sequence of repetitive DNA families to which the first clones respectively belong and variant sequences are then identified by selecting clones having a pattern of hybridization with genomic DNA dissimilar to the hybridization pattern shown by the respective families. In another embodiment, variant sequences are selected from a sequence of a known repetitive DNA family. The selected variant sequence is classified as chromosome specific, chromosome preferential, or chromosome nonspecific. Sequences which are classified as chromosome preferential are further sequenced and regions are identified having a low homology with other regions of the chromosome preferential sequence or with known sequences of other family members and consensus sequences of the repetitive DNA families for the chromosome preferential sequences. The selected low homology regions are then hybridized with chromosomes to determine those low homology regions hybridized with a specific chromosome under normal stringency conditions.

Sequencing papaya X and Yh chromosomes reveals molecular basis of incipient sex chromosome evolution

PubMed Central

Wang, Jianping; Na, Jong-Kuk; Yu, Qingyi; Gschwend, Andrea R.; Han, Jennifer; Zeng, Fanchang; Aryal, Rishi; VanBuren, Robert; Murray, Jan E.; Zhang, Wenli; Navajas-Pérez, Rafael; Feltus, F. Alex; Lemke, Cornelia; Tong, Eric J.; Chen, Cuixia; Man Wai, Ching; Singh, Ratnesh; Wang, Ming-Li; Min, Xiang Jia; Alam, Maqsudul; Charlesworth, Deborah; Moore, Paul H.; Jiang, Jiming; Paterson, Andrew H.; Ming, Ray

2012-01-01

Sex determination in papaya is controlled by a recently evolved XY chromosome pair, with two slightly different Y chromosomes controlling the development of males (Y) and hermaphrodites (Yh). To study the events of early sex chromosome evolution, we sequenced the hermaphrodite-specific region of the Yh chromosome (HSY) and its X counterpart, yielding an 8.1-megabase (Mb) HSY pseudomolecule, and a 3.5-Mb sequence for the corresponding X region. The HSY is larger than the X region, mostly due to retrotransposon insertions. The papaya HSY differs from the X region by two large-scale inversions, the first of which likely caused the recombination suppression between the X and Yh chromosomes, followed by numerous additional chromosomal rearrangements. Altogether, including the X and/or HSY regions, 124 transcription units were annotated, including 50 functional pairs present in both the X and HSY. Ten HSY genes had functional homologs elsewhere in the papaya autosomal regions, suggesting movement of genes onto the HSY, whereas the X region had none. Sequence divergence between 70 transcripts shared by the X and HSY revealed two evolutionary strata in the X chromosome, corresponding to the two inversions on the HSY, the older of which evolved about 7.0 million years ago. Gene content differences between the HSY and X are greatest in the older stratum, whereas the gene content and order of the collinear regions are identical. Our findings support theoretical models of early sex chromosome evolution. PMID:22869747

Sequencing papaya X and Yh chromosomes reveals molecular basis of incipient sex chromosome evolution.

PubMed

Wang, Jianping; Na, Jong-Kuk; Yu, Qingyi; Gschwend, Andrea R; Han, Jennifer; Zeng, Fanchang; Aryal, Rishi; VanBuren, Robert; Murray, Jan E; Zhang, Wenli; Navajas-Pérez, Rafael; Feltus, F Alex; Lemke, Cornelia; Tong, Eric J; Chen, Cuixia; Wai, Ching Man; Singh, Ratnesh; Wang, Ming-Li; Min, Xiang Jia; Alam, Maqsudul; Charlesworth, Deborah; Moore, Paul H; Jiang, Jiming; Paterson, Andrew H; Ming, Ray

2012-08-21

Sex determination in papaya is controlled by a recently evolved XY chromosome pair, with two slightly different Y chromosomes controlling the development of males (Y) and hermaphrodites (Y(h)). To study the events of early sex chromosome evolution, we sequenced the hermaphrodite-specific region of the Y(h) chromosome (HSY) and its X counterpart, yielding an 8.1-megabase (Mb) HSY pseudomolecule, and a 3.5-Mb sequence for the corresponding X region. The HSY is larger than the X region, mostly due to retrotransposon insertions. The papaya HSY differs from the X region by two large-scale inversions, the first of which likely caused the recombination suppression between the X and Y(h) chromosomes, followed by numerous additional chromosomal rearrangements. Altogether, including the X and/or HSY regions, 124 transcription units were annotated, including 50 functional pairs present in both the X and HSY. Ten HSY genes had functional homologs elsewhere in the papaya autosomal regions, suggesting movement of genes onto the HSY, whereas the X region had none. Sequence divergence between 70 transcripts shared by the X and HSY revealed two evolutionary strata in the X chromosome, corresponding to the two inversions on the HSY, the older of which evolved about 7.0 million years ago. Gene content differences between the HSY and X are greatest in the older stratum, whereas the gene content and order of the collinear regions are identical. Our findings support theoretical models of early sex chromosome evolution.

Mapping of aldose reductase gene sequences to human chromosomes 1, 3, 7, 9, 11, and 13

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

Bateman, J.B.; Kojis, T.; Heinzmann, C.

1993-09-01

Aldose reductase (alditol:NAD(P)+ 1-oxidoreductase; EC 1.1.1.21) (AR) catalyzes the reduction of several aldehydes, including that of glucose, to the corresponding sugar alcohol. Using a complementary DNA clone encoding human AR, the authors mapped the gene sequences to human chromosomes 1, 3, 7, 9, 11, 13, 14, and 18 by somatic cell hybridization. By in situ hybridization analysis, sequences were localized to human chromosomes 1q32-q43, 3p12, 7q31-q35, 9q22, 11p14-p15, and 13q14-q21. As a putative functional AR gene has been mapped to chromosome 7 and a putative pseudogene to chromosome 3, the sequences on the other seven chromosomes may represent other activemore » genes, non-aldose reductase homologous sequences, or pseudogenes. 24 refs., 3 figs., 2 tabs.« less

Sex chromosome loss and the pseudoautosomal region genes in hematological malignancies

PubMed Central

Weng, Stephanie; Stoner, Samuel A.; Zhang, Dong-Er

2016-01-01

Cytogenetic aberrations, such as chromosomal translocations, aneuploidy, and amplifications, are frequently detected in hematological malignancies. For many of the common autosomal aberrations, the mechanisms underlying their roles in cancer development have been well-characterized. On the contrary, although loss of a sex chromosome is observed in a broad range of hematological malignancies, how it cooperates in disease development is less understood. Nevertheless, it has been postulated that tumor suppressor genes reside on the sex chromosomes. Although the X and Y sex chromosomes are highly divergent, the pseudoautosomal regions are homologous between both chromosomes. Here, we review what is currently known about the pseudoautosomal region genes in the hematological system. Additionally, we discuss implications for haploinsufficiency of critical pseudoautosomal region sex chromosome genes, driven by sex chromosome loss, in promoting hematological malignancies. Because mechanistic studies on disease development rely heavily on murine models, we also discuss the challenges and caveats of existing models, and propose alternatives for examining the involvement of pseudoautosomal region genes and loss of a sex chromosome in vivo. With the widespread detection of loss of a sex chromosome in different hematological malignances, the elucidation of the role of pseudoautosomal region genes in the development and progression of these diseases would be invaluable to the field. PMID:27655702

qnrA6 genetic environment and quinolone resistance conferred on Proteus mirabilis.

PubMed

Jayol, Aurélie; Janvier, Frédéric; Guillard, Thomas; Chau, Françoise; Mérens, Audrey; Robert, Jérôme; Fantin, Bruno; Berçot, Béatrice; Cambau, Emmanuelle

2016-04-01

To determine the genetic location and environment of the qnrA6 gene in Proteus mirabilis PS16 where it was first described and to characterize the quinolone resistance qnrA6 confers. Transformation experiments and Southern blotting were performed for plasmid and genomic DNA of P. mirabilis PS16 to determine the qnrA6 location. Combinatorial PCRs with primers in qnrA6 and genes usually surrounding qnrA genes were used to determine the genetic environment. The qnrA6 coding region, including or not the promoter region, was cloned into vectors pTOPO and pBR322 and the MICs of six quinolones were measured for transformants of Escherichia coli TOP10 and P. mirabilis ATCC 29906 Rif(R). qnrA6 was shown to be chromosomally encoded in P. mirabilis PS16 and its genetic environment was 81%-87% similar to that of qnrA2 in the Shewanella algae chromosome. The 5138 bp region up- and downstream of qnrA6 contained an IS10 sequence surrounded by two ISCR1. This resulted in qnrA6 being displaced 1.9 kb from its native promoter but supplied a promoter present in ISCR1. qnrA6 cloned into pTOPO and pBR322 conferred a 4-32-fold increase in fluoroquinolone MICs when expressed in E. coli but only 2-3-fold in P. mirabilis. When including the promoter region, a further increase in resistance was observed in both species, reaching MIC values above clinical breakpoints for only P. mirabilis. qnrA6 is the first chromosomally located qnrA gene described in Enterobacteriaceae. The quinolone resistance conferred by qnrA6 depends on the proximity of an efficient promoter and the host strain where it is expressed. © The Author 2016. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

A Balanced Chromosomal Translocation Disrupting ARHGEF9 Is Associated With Epilepsy, Anxiety, Aggression, and Mental Retardation

PubMed Central

Kalscheuer, Vera M.; Musante, Luciana; Fang, Cheng; Hoffmann, Kirsten; Fuchs, Celine; Carta, Eloisa; Deas, Emma; Venkateswarlu, Kanamarlapudi; Menzel, Corinna; Ullmann, Reinhard; Tommerup, Niels; Dalprà, Leda; Tzschach, Andreas; Selicorni, Angelo; Lüscher, Bernhard; Ropers, Hans-Hilger; Harvey, Kirsten; Harvey, Robert J.

2013-01-01

Clustering of inhibitory γ-aminobutyric acidA (GABAA) and glycine receptors at synapses is thought to involve key interactions between the receptors, a “scaffolding” protein known as gephyrin and the RhoGEF collybistin. We report the identification of a balanced chromosomal translocation in a female patient presenting with a disturbed sleep-wake cycle, late-onset epileptic seizures, increased anxiety, aggressive behavior, and mental retardation, but not hyperekplexia. Fine mapping of the breakpoint indicates disruption of the collybistin gene (ARHGEF9) on chromosome Xq11, while the other breakpoint lies in a region of 18q11 that lacks any known or predicted genes. We show that defective collybistin transcripts are synthesized and exons 7–10 are replaced by cryptic exons from chromosomes X and 18. These mRNAs no longer encode the pleckstrin homology (PH) domain of collybistin, which we now show binds phosphatidylinositol-3-phosphate (PI3P/ PtdIns-3-P), a phosphoinositide with an emerging role in membrane trafficking and signal transduction, rather than phosphatidylinositol 3,4,5-trisphosphate (PIP3/PtdIns-3,4,5-P) as previously suggested in the “membrane activation model” of gephyrin clustering. Consistent with this finding, expression of truncated collybistin proteins in cultured neurons interferes with synaptic localization of endogenous gephyrin and GABAA receptors. These results suggest that collybistin has a key role in membrane trafficking of gephyrin and selected GABAA receptor subtypes involved in epilepsy, anxiety, aggression, insomnia, and learning and memory. PMID:18615734

Localization of a gene for autosomal dominant amelogenesis imperfecta (ADAI) to chromosome 4q

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

Forsman, K.; Lind. L.; Westermark, E.

1994-09-01

Amelogenesis imperfecta (AI), a disorder affecting the formation of enamel, is significantly more common in Northern Sweden than in other parts of the world. The disease is genetically and clinically heterogenous, and autosomal dominant, autosomal recessive and X-linked inheritance patterns have been recognized. Linkage analysis has identified two different loci for X-linked AI, one of which is identical to the gene encoding the enamel protein amelogenin. However, in families with an autosomal inheritance pattern for AI, the genetic basis of the disease still remains unknown. We report a linkage analysis study performed on three Swedish families where the affected membersmore » had an autosomal dominant variant of AI (ADAI) clinically characterized as local hypoplastic. Significant linkage to microsatellite markers on chromosome 4q were obtained, with a maximum lod score of 5.55 for the marker D4S428. Recombinations in the family localized the ADAI locus to the interval between D4S392 and D4S395. This chromosome region contains both a locus for the dental disorder dentinogenesis imperfecta and the albumin gene. Serum albumin has been suggested to play a role in enamel formation, and the albumin gene is therefore a candidate gene for this genetic disease.« less

MITOSTATIN, a putative tumor suppressor on chromosome 12q24.1, is downregulated in human bladder and breast cancer.

PubMed

Vecchione, A; Fassan, M; Anesti, V; Morrione, A; Goldoni, S; Baldassarre, G; Byrne, D; D'Arca, D; Palazzo, J P; Lloyd, J; Scorrano, L; Gomella, L G; Iozzo, R V; Baffa, R

2009-01-15

Allelic deletions on human chromosome 12q24 are frequently reported in a variety of malignant neoplasms, indicating the presence of a tumor suppressor gene(s) in this chromosomal region. However, no reasonable candidate has been identified so far. In this study, we report the cloning and functional characterization of a novel mitochondrial protein with tumor suppressor activity, henceforth designated MITOSTATIN. Human MITOSTATIN was found within a 3.2-kb transcript, which encoded a approximately 62 kDa, ubiquitously expressed protein with little homology to any known protein. We found homozygous deletions and mutations of MITOSTATIN gene in approximately 5 and approximately 11% of various cancer-derived cells and solid tumors, respectively. When transiently overexpressed, MITOSTATIN inhibited colony formation, tumor cell growth and was proapoptotic, all features shared by established tumor suppressor genes. We discovered a specific link between MITOSTATIN overexpression and downregulation of Hsp27. Conversely, MITOSTATIN knockdown cells showed an increase in cell growth and cell survival rates. Finally, MITOSTATIN expression was significantly reduced in primary bladder and breast tumors, and its reduction was associated with advanced tumor stages. Our findings support the hypothesis that MITOSTATIN has many hallmarks of a classical tumor suppressor in solid tumors and may play an important role in cancer development and progression.

Molecular cloning, structure, and chromosomal localization of the mouse LIM/homeobox gene Lhx5

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

Bertuzzi, S.; Sheng, Hui Z.; Westphal, H.

1996-09-01

Lhx5, the mouse ortholog of the Xenopus Xlim-5, is a LIM/homeobox gene expressed in the central nervous system during both embryonic development and adulthood. During development its domain of expression is mainly localized at the most anterior portion of the neural tube, and it precedes the morphological differentiation of the forebrain; for this reason we believe that Lhx5 could play an important role in forebrain patterning. Here we present the structural organization and the chromosomal localization of the Lhx5 gene. The gene is composed of five exons spanning more than 10 kb of genomic sequence. The first and second LIMmore » domains are encoded by the first and second exon, while the codons of the homeobox are split between the third and the fourth exons. The structure of Lhx5 is similar to that of other LIM/homeodomain proteins, Lxh1/lim1 and Lhx3/lim3, but differs from that of other LIM genes, such as mec3 and LMO1/Rbtn1, in which the codons for the LIM domains are interrupted by introns. We have mapped Lhx5 to the central region of mouse chromosome 5. 38 refs., 4 figs.« less

Deletion of a Single-Copy Trna Affects Microtubule Function in Saccharomyces Cerevisiae

PubMed Central

Reijo, R. A.; Cho, D. S.; Huffaker, T. C.

1993-01-01

rts1-1 was identified as an extragenic suppressor of tub2-104, a cold-sensitive allele of the sole gene encoding β-tubulin in the yeast, Saccharomyces cerevisiae. In addition, rts1-1 cells are heat sensitive and resistant to the microtubule-destabilizing drug, benomyl. The rts1-1 mutation is a deletion of approximately 5 kb of genomic DNA on chromosome X that includes one open reading frame and three tRNA genes. Dissection of this region shows that heat sensitivity is due to deletion of the open reading frame (HIT1). Suppression and benomyl resistance are caused by deletion of the gene encoding a tRNA(AGG)(Arg) (HSX1). Northern analysis of rts1-1 cells indicates that HSX1 is the only gene encoding this tRNA. Deletion of HSX1 does not suppress the tub2-104 mutation by misreading at the AGG codons in TUB2. It also does not suppress by interfering with the protein arginylation that targets certain proteins for degradation. These results leave open the prospect that this tRNA(AGG)(Arg) plays a novel role in the cell. PMID:8307335

A Large Pseudoautosomal Region on the Sex Chromosomes of the Frog Silurana tropicalis

PubMed Central

Bewick, Adam J.; Chain, Frédéric J.J.; Zimmerman, Lyle B.; Sesay, Abdul; Gilchrist, Michael J.; Owens, Nick D.L.; Seifertova, Eva; Krylov, Vladimir; Macha, Jaroslav; Tlapakova, Tereza; Kubickova, Svatava; Cernohorska, Halina; Zarsky, Vojtech; Evans, Ben J.

2013-01-01

Sex chromosome divergence has been documented across phylogenetically diverse species, with amphibians typically having cytologically nondiverged (“homomorphic”) sex chromosomes. With an aim of further characterizing sex chromosome divergence of an amphibian, we used “RAD-tags” and Sanger sequencing to examine sex specificity and heterozygosity in the Western clawed frog Silurana tropicalis (also known as Xenopus tropicalis). Our findings based on approximately 20 million genotype calls and approximately 200 polymerase chain reaction-amplified regions across multiple male and female genomes failed to identify a substantially sized genomic region with genotypic hallmarks of sex chromosome divergence, including in regions known to be tightly linked to the sex-determining region. We also found that expression and molecular evolution of genes linked to the sex-determining region did not differ substantially from genes in other parts of the genome. This suggests that the pseudoautosomal region, where recombination occurs, comprises a large portion of the sex chromosomes of S. tropicalis. These results may in part explain why African clawed frogs have such a high incidence of polyploidization, shed light on why amphibians have a high rate of sex chromosome turnover, and raise questions about why homomorphic sex chromosomes are so prevalent in amphibians. PMID:23666865

The cnm locus, a canine homologue of human autosomal forms of centronuclear myopathy, maps to chromosome 2.

PubMed

Tiret, Laurent; Blot, Stéphane; Kessler, Jean-Louis; Gaillot, Hugues; Breen, Matthew; Panthier, Jean-Jacques

2003-09-01

Myotubular/centronuclear myopathies are a nosological group of hereditary disorders characterised by severe architectural and metabolic remodelling of skeletal muscle fibres. In most myofibres, nuclei are found at an abnormal central position within a halo devoid of myofibrillar proteins. The X-linked form (myotubular myopathy) is the most prevalent and severe form in human, leading to death during early postnatal life. Maturation of fibres is not completed and fibres resemble myotubes. Linkage analysis in human has helped to identify MTM1 as the morbid gene. MTM1 encodes myotubularin, a dual protein phosphatase. In families in which myotubular myopathy segregates, detected mutations in MTM1 abolish the specific phosphatase activity targeting the second messenger phosphatidylinositol 3-phosphate. Autosomal forms (centronuclear) have a later onset and are often compatible with life. At birth, fibres are normally constituted but progressively follow remodelling with a secondary centralisation of nuclei. Their prevalence is low; hence, no linkage data can be performed and no molecular aetiology is known. In the Labrador Retriever, a spontaneous disorder strikingly mimics the clinical evolution of the human centronuclear myopathy. We have established a canine pedigree and show that the disorder segregates as an autosomal recessive trait in that pedigree. We have further mapped the dog locus to a region on chromosome 2 that is orthologous to human chromosome 10p. To date, no human MTM1 gene member has been mapped to this genetic region. This report thus describes the first spontaneous mammalian model of centronuclear myopathy and defines a new locus for this group of diseases.

Development of genetic tools for in vivo virulence analysis of Streptococcus sanguinis.

PubMed

Turner, Lauren Senty; Das, Sankar; Kanamoto, Taisei; Munro, Cindy L; Kitten, Todd

2009-08-01

Completion of the genome sequence of Streptococcus sanguinis SK36 necessitates tools for further characterization of this species. It is often desirable to insert antibiotic resistance markers and other exogenous genes into the chromosome; therefore, we sought to identify a chromosomal site for ectopic expression of foreign genes, and to verify that insertion into this site did not affect important cellular phenotypes. We designed three plasmid constructs for insertion of erm, aad9 or tetM resistance determinants into a genomic region encoding only a small (65 aa) hypothetical protein. To determine whether this insertion affected important cellular properties, SK36 and its erythromycin-resistant derivative, JFP36, were compared for: (i) growth in vitro, (ii) genetic competence, (iii) biofilm formation and (iv) virulence for endocarditis in the rabbit model of infective endocarditis (IE). The spectinomycin-resistant strain, JFP56, and tetracycline-resistant strain, JFP76, were also tested for virulence in vivo. Insertion of erm did not affect growth, competence or biofilm development of JFP36. Recovery of bacteria from heart valves of co-inoculated rabbits was similar to wild-type for JFP36, JFP56 and JFP76, indicating that IE virulence was not significantly affected. The capacity for mutant complementation in vivo was explored in an avirulent ssaB mutant background. Expression of ssaB from its predicted promoter in the target region restored IE virulence. Thus, the chromosomal site utilized is a good candidate for further manipulations of S. sanguinis. In addition, the resistant strains developed may be further applied as controls to facilitate screening for virulence factors in vivo.

Development of genetic tools for in vivo virulence analysis of Streptococcus sanguinis

PubMed Central

Senty Turner, Lauren; Das, Sankar; Kanamoto, Taisei; Munro, Cindy L.; Kitten, Todd

2009-01-01

Completion of the genome sequence of Streptococcus sanguinis SK36 necessitates tools for further characterization of this species. It is often desirable to insert antibiotic resistance markers and other exogenous genes into the chromosome; therefore, we sought to identify a chromosomal site for ectopic expression of foreign genes, and to verify that insertion into this site did not affect important cellular phenotypes. We designed three plasmid constructs for insertion of erm, aad9 or tetM resistance determinants into a genomic region encoding only a small (65 aa) hypothetical protein. To determine whether this insertion affected important cellular properties, SK36 and its erythromycin-resistant derivative, JFP36, were compared for: (i) growth in vitro, (ii) genetic competence, (iii) biofilm formation and (iv) virulence for endocarditis in the rabbit model of infective endocarditis (IE). The spectinomycin-resistant strain, JFP56, and tetracycline-resistant strain, JFP76, were also tested for virulence in vivo. Insertion of erm did not affect growth, competence or biofilm development of JFP36. Recovery of bacteria from heart valves of co-inoculated rabbits was similar to wild-type for JFP36, JFP56 and JFP76, indicating that IE virulence was not significantly affected. The capacity for mutant complementation in vivo was explored in an avirulent ssaB mutant background. Expression of ssaB from its predicted promoter in the target region restored IE virulence. Thus, the chromosomal site utilized is a good candidate for further manipulations of S. sanguinis. In addition, the resistant strains developed may be further applied as controls to facilitate screening for virulence factors in vivo. PMID:19423626

Chromosomal location and gene paucity of the male specific region on papaya Y chromosome.

PubMed

Yu, Qingyi; Hou, Shaobin; Hobza, Roman; Feltus, F Alex; Wang, Xiue; Jin, Weiwei; Skelton, Rachel L; Blas, Andrea; Lemke, Cornelia; Saw, Jimmy H; Moore, Paul H; Alam, Maqsudul; Jiang, Jiming; Paterson, Andrew H; Vyskot, Boris; Ming, Ray

2007-08-01

Sex chromosomes in flowering plants evolved recently and many of them remain homomorphic, including those in papaya. We investigated the chromosomal location of papaya's small male specific region of the hermaphrodite Y (Yh) chromosome (MSY) and its genomic features. We conducted chromosome fluorescence in situ hybridization mapping of Yh-specific bacterial artificial chromosomes (BACs) and placed the MSY near the centromere of the papaya Y chromosome. Then we sequenced five MSY BACs to examine the genomic features of this specialized region, which resulted in the largest collection of contiguous genomic DNA sequences of a Y chromosome in flowering plants. Extreme gene paucity was observed in the papaya MSY with no functional gene identified in 715 kb MSY sequences. A high density of retroelements and local sequence duplications were detected in the MSY that is suppressed for recombination. Location of the papaya MSY near the centromere might have provided recombination suppression and fostered paucity of genes in the male specific region of the Y chromosome. Our findings provide critical information for deciphering the sex chromosomes in papaya and reference information for comparative studies of other sex chromosomes in animals and plants.

Chromosomal instability in Streptomyces avermitilis: major deletion in the central region and stable circularized chromosome

PubMed Central

2010-01-01

Background The chromosome of Streptomyces has been shown to be unstable, frequently undergoing gross chromosomal rearrangements. However, the mechanisms underlying this phenomenon remain unclear, with previous studies focused on two chromosomal ends as targets for rearrangements. Here we investigated chromosomal instability of Streptomyces avermitilis, an important producer of avermectins, and characterized four gross chromosomal rearrangement events, including a major deletion in the central region. The present findings provide a valuable contribution to the mechanistic study of genetic instability in Streptomyces. Results Thirty randomly-selected "bald" mutants derived from the wild-type strain all contained gross chromosomal rearrangements of various types. One of the bald mutants, SA1-8, had the same linear chromosomal structure as the high avermectin-producing mutant 76-9. Chromosomes of both strains displayed at least three independent chromosomal rearrangements, including chromosomal arm replacement to form new 88-kb terminal inverted repeats (TIRs), and two major deletions. One of the deletions eliminated the 36-kb central region of the chromosome, but surprisingly did not affect viability of the cells. The other deletion (74-kb) was internal to the right chromosomal arm. The chromosome of another bald mutant, SA1-6, was circularized with deletions at both ends. No obvious homology was found in all fusion sequences. Generational stability analysis showed that the chromosomal structure of SA1-8 and SA1-6 was stable. Conclusions Various chromosomal rearrangements, including chromosomal arm replacement, interstitial deletions and chromosomal circularization, occurred in S. avermitilis by non-homologous recombination. The finding of an inner deletion involving in the central region of S. avermitilis chromosome suggests that the entire Streptomyces chromosome may be the target for rearrangements, which are not limited, as previously reported, to the two chromosomal ends. PMID:20653985

The abundant extrachromosomal DNA content of the Spiroplasma citri GII3-3X genome

PubMed Central

Saillard, Colette; Carle, Patricia; Duret-Nurbel, Sybille; Henri, Raphaël; Killiny, Nabil; Carrère, Sébastien; Gouzy, Jérome; Bové, Joseph-Marie; Renaudin, Joël; Foissac, Xavier

2008-01-01

Background Spiroplama citri, the causal agent of citrus stubborn disease, is a bacterium of the class Mollicutes and is transmitted by phloem-feeding leafhopper vectors. In order to characterize candidate genes potentially involved in spiroplasma transmission and pathogenicity, the genome of S. citri strain GII3-3X is currently being deciphered. Results Assembling 20,000 sequencing reads generated seven circular contigs, none of which fit the 1.8 Mb chromosome map or carried chromosomal markers. These contigs correspond to seven plasmids: pSci1 to pSci6, with sizes ranging from 12.9 to 35.3 kbp and pSciA of 7.8 kbp. Plasmids pSci were detected as multiple copies in strain GII3-3X. Plasmid copy numbers of pSci1-6, as deduced from sequencing coverage, were estimated at 10 to 14 copies per spiroplasma cell, representing 1.6 Mb of extrachromosomal DNA. Genes encoding proteins of the TrsE-TraE, Mob, TraD-TraG, and Soj-ParA protein families were predicted in most of the pSci sequences, in addition to members of 14 protein families of unknown function. Plasmid pSci6 encodes protein P32, a marker of insect transmissibility. Plasmids pSci1-5 code for eight different S. citri adhesion-related proteins (ScARPs) that are homologous to the previously described protein P89 and the S. kunkelii SkARP1. Conserved signal peptides and C-terminal transmembrane alpha helices were predicted in all ScARPs. The predicted surface-exposed N-terminal region possesses the following elements: (i) 6 to 8 repeats of 39 to 42 amino acids each (sarpin repeats), (ii) a central conserved region of 330 amino acids followed by (iii) a more variable domain of about 110 amino acids. The C-terminus, predicted to be cytoplasmic, consists of a 27 amino acid stretch enriched in arginine and lysine (KR) and an optional 23 amino acid stretch enriched in lysine, aspartate and glutamate (KDE). Plasmids pSci mainly present a linear increase of cumulative GC skew except in regions presenting conserved hairpin structures. Conclusion The genome of S. citri GII3-3X is characterized by abundant extrachromosomal elements. The pSci plasmids could not only be vertically inherited but also horizontally transmitted, as they encode proteins usually involved in DNA element partitioning and cell to cell DNA transfer. Because plasmids pSci1-5 encode surface proteins of the ScARP family and pSci6 was recently shown to confer insect transmissibility, diversity and abundance of S. citri plasmids may essentially aid the rapid adaptation of S. citri to more efficient transmission by different insect vectors and to various plant hosts. PMID:18442384

Deep ancestry of mammalian X chromosome revealed by comparison with the basal tetrapod Xenopus tropicalis.

PubMed

Mácha, Jaroslav; Teichmanová, Radka; Sater, Amy K; Wells, Dan E; Tlapáková, Tereza; Zimmerman, Lyle B; Krylov, Vladimír

2012-07-16

The X and Y sex chromosomes are conspicuous features of placental mammal genomes. Mammalian sex chromosomes arose from an ordinary pair of autosomes after the proto-Y acquired a male-determining gene and degenerated due to suppression of X-Y recombination. Analysis of earlier steps in X chromosome evolution has been hampered by the long interval between the origins of teleost and amniote lineages as well as scarcity of X chromosome orthologs in incomplete avian genome assemblies. This study clarifies the genesis and remodelling of the Eutherian X chromosome by using a combination of sequence analysis, meiotic map information, and cytogenetic localization to compare amniote genome organization with that of the amphibian Xenopus tropicalis. Nearly all orthologs of human X genes localize to X. tropicalis chromosomes 2 and 8, consistent with an ancestral X-conserved region and a single X-added region precursor. This finding contradicts a previous hypothesis of three evolutionary strata in this region. Homologies between human, opossum, chicken and frog chromosomes suggest a single X-added region predecessor in therian mammals, corresponding to opossum chromosomes 4 and 7. A more ancient X-added ancestral region, currently extant as a major part of chicken chromosome 1, is likely to have been present in the progenitor of synapsids and sauropsids. Analysis of X chromosome gene content emphasizes conservation of single protein coding genes and the role of tandem arrays in formation of novel genes. Chromosomal regions orthologous to Therian X chromosomes have been located in the genome of the frog X. tropicalis. These X chromosome ancestral components experienced a series of fusion and breakage events to give rise to avian autosomes and mammalian sex chromosomes. The early branching tetrapod X. tropicalis' simple diploid genome and robust synteny to amniotes greatly enhances studies of vertebrate chromosome evolution.

Deep ancestry of mammalian X chromosome revealed by comparison with the basal tetrapod Xenopus tropicalis

PubMed Central

2012-01-01

Background The X and Y sex chromosomes are conspicuous features of placental mammal genomes. Mammalian sex chromosomes arose from an ordinary pair of autosomes after the proto-Y acquired a male-determining gene and degenerated due to suppression of X-Y recombination. Analysis of earlier steps in X chromosome evolution has been hampered by the long interval between the origins of teleost and amniote lineages as well as scarcity of X chromosome orthologs in incomplete avian genome assemblies. Results This study clarifies the genesis and remodelling of the Eutherian X chromosome by using a combination of sequence analysis, meiotic map information, and cytogenetic localization to compare amniote genome organization with that of the amphibian Xenopus tropicalis. Nearly all orthologs of human X genes localize to X. tropicalis chromosomes 2 and 8, consistent with an ancestral X-conserved region and a single X-added region precursor. This finding contradicts a previous hypothesis of three evolutionary strata in this region. Homologies between human, opossum, chicken and frog chromosomes suggest a single X-added region predecessor in therian mammals, corresponding to opossum chromosomes 4 and 7. A more ancient X-added ancestral region, currently extant as a major part of chicken chromosome 1, is likely to have been present in the progenitor of synapsids and sauropsids. Analysis of X chromosome gene content emphasizes conservation of single protein coding genes and the role of tandem arrays in formation of novel genes. Conclusions Chromosomal regions orthologous to Therian X chromosomes have been located in the genome of the frog X. tropicalis. These X chromosome ancestral components experienced a series of fusion and breakage events to give rise to avian autosomes and mammalian sex chromosomes. The early branching tetrapod X. tropicalis’ simple diploid genome and robust synteny to amniotes greatly enhances studies of vertebrate chromosome evolution. PMID:22800176

Cloning of cDNA encoding the nuclear form of chicken sterol response element binding protein-2 (SREBP-2), chromosomal localization, and tissue expression of chicken SREBP-1 and -2 genes.

PubMed

Assaf, S; Hazard, D; Pitel, F; Morisson, M; Alizadeh, M; Gondret, F; Diot, C; Vignal, A; Douaire, M; Lagarrigue, S

2003-01-01

Sterol regulatory element binding protein-1 and -2 (SREBP-1 and -2) are key transcription factors involved in the biosynthesis of cholesterol and fatty adds. The SREBP have mainly been studied in rodents in which lipogenesis is regulated in both liver and adipose tissue. There is, however, a paucity of information on birds, in which lipogenesis occurs essentially in the liver as in humans. As a prelude to the investigation of the role of SREBP in lipid metabolism regulation in chicken, we sequenced the cDNA, encoding the mature nuclear form of chicken SREBP-2 protein, mapped SREBP-1 and -2 genes and studied their tissue expressions. The predicted chicken SREBP-2 amino acid sequence shows a 77 to 79% identity with human, mouse, and hamster homologues, with a nearly perfect conservation in all the important functional motifs, basic, helix-loop-helix, and leucine zipper (bHLH-Zip) region as well as cleavage sites. As in the human genome, SREBP-1 and SREBP-2 chicken genes are located on two separate chromosomes, respectively microchromosome 14 and macrochromosome 1. Tissue expression data show that SREBP-1 and SREBP-2 are expressed in a wide variety of tissues in chicken. However, unlike SREBP-2, SREBP-1 is expressed preferentially in the liver and uropygial gland, suggesting an important role of SREBP-1 in the regulation of lipogenesis in avian species.

The unusually large Plasmodium telomerase reverse-transcriptase localizes in a discrete compartment associated with the nucleolus

PubMed Central

Figueiredo, Luisa M.; Rocha, Eduardo P. C.; Mancio-Silva, Liliana; Prevost, Christine; Hernandez-Verdun, Danièle; Scherf, Artur

2005-01-01

Telomerase replicates chromosome ends, a function necessary for maintaining genome integrity. We have identified the gene that encodes the catalytic reverse transcriptase (RT) component of this enzyme in the malaria parasite Plasmodium falciparum (PfTERT) as well as the orthologous genes from two rodent and one simian malaria species. PfTERT is predicted to encode a basic protein that contains the major sequence motifs previously identified in known telomerase RTs (TERTs). At ∼2500 amino acids, PfTERT is three times larger than other characterized TERTs. We observed remarkable sequence diversity between TERT proteins of different Plasmodial species, with conserved domains alternating with hypervariable regions. Immunofluorescence analysis revealed that PfTERT is expressed in asexual blood stage parasites that have begun DNA synthesis. Surprisingly, rather than at telomere clusters, PfTERT typically localizes into a discrete nuclear compartment. We further demonstrate that this compartment is associated with the nucleolus, hereby defined for the first time in P.falciparum. PMID:15722485

Retention of duplicated ITAM-containing transmembrane signaling subunits in the tetraploid amphibian species Xenopus laevis

PubMed Central

Guselnikov, S.V.; Grayfer, L.; De Jesús Andino, F.; Rogozin, I.B.; Robert, J.; Taranin, A.V.

2015-01-01

The ITAM-bearing transmembrane signaling subunits (TSS) are indispensable components of activating leukocyte receptor complexes. The TSS-encoding genes map to paralogous chromosomal regions, which are thought to arise from ancient genome tetraploidization(s). To assess a possible role of tetraploidization in the TSS evolution, we studied TSS and other functionally linked genes in the amphibian species Xenopus laevis whose genome was duplicated about 40 MYR ago. We found that X. laevis has retained a duplicated set of sixteen TSS genes, all except one being transcribed. Furthermore, duplicated TCRα loci and genes encoding TSS-coupling protein kinases have also been retained. No clear evidence for functional divergence of the TSS paralogs was obtained from gene expression and sequence analyses. We suggest that the main factor of maintenance of duplicated TSS genes in X. laevis was a protein dosage effect and that this effect might have facilitated the TSS set expansion in early vertebrates. PMID:26170006

Type 3 Fimbriae Encoded on Plasmids Are Expressed from a Unique Promoter without Affecting Host Motility, Facilitating an Exceptional Phenotype That Enhances Conjugal Plasmid Transfer

PubMed Central

Madsen, Jonas Stenløkke; Riber, Leise; Kot, Witold; Basfeld, Alrun; Burmølle, Mette; Hansen, Lars Hestbjerg; Sørensen, Søren Johannes

2016-01-01

Horizontal gene transfer (HGT), the transmission of genetic material to a recipient that is not the progeny of the donor, is fundamental in bacterial evolution. HGT is often mediated by mobile genetic elements such as conjugative plasmids, which may be in conflict with the chromosomal elements of the genome because they are independent replicons that may petition their own evolutionary strategy. Here we study differences between type 3 fimbriae encoded on wild type plasmids and in chromosomes. Using known and newly characterized plasmids we show that the expression of type 3 fimbriae encoded on plasmids is systematically different, as MrkH, a c-di-GMP dependent transcriptional activator is not needed for strong expression of the fimbriae. MrkH is required for expression of type 3 fimbriae of the Klebsiella pneumoniae chromosome, wherefrom the fimbriae operon (mrkABCDF) of plasmids is believed to have originated. We find that mrkABCDFs of plasmids are highly expressed via a unique promoter that differs from the original Klebsiella promoter resulting in fundamental behavioral consequences. Plasmid associated mrkABCDFs did not influence the swimming behavior of the host, that hereby acquired an exceptional phenotype being able to both actively swim (planktonic behavior) and express biofilm associated fimbriae (sessile behavior). We show that this exceptional phenotype enhances the conjugal transfer of the plasmid. PMID:27627107

Efflux pump-mediated benzalkonium chloride resistance in Listeria monocytogenes isolated from retail food.

PubMed

Jiang, Xiaobing; Yu, Tao; Liang, Yu; Ji, Shengdong; Guo, Xiaowei; Ma, Jianmin; Zhou, Lijun

2016-01-18

In this study, efflux pump-mediated benzalkonium chloride (BC) resistance, including plasmid-encoded (Qac protein family and BcrABC) and chromosome-borne efflux pumps, was investigated in Listeria monocytogenes from retail food in China. Among the 59 L. monocytogenes strains, 13 (22.0%) strains were resistant to BC. The PCR results showed that bcrABC was harbored by 2 of 13 BC resistant strains. However, none of the qac genes were detected among the 59 strains. The bcrABC was absent in both of the plasmid cured strains, indicating that this BC resistance determinant was plasmid-encoded in the two bcrABC-positive strains. In the presence of reserpine, most of the bcrABC-negative strains had decreases in the MICs of BC, suggesting the existence of other efflux pumps and their role in BC resistance. After exposed to reserpine, the reduction in BC MICs was observed in the two cured strains, indicating that efflux pumps located on chromosome was also involved in BC resistance. Our findings suggest that food products may act as reservoirs for BC resistant isolates of L. monocytogenes and plasmid- and chromosome-encoded efflux pumps could mediate the BC resistance of L. monocytogenes, which is especially relevant to the adaption of this organism in food-related environments with frequent BC use. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization of the 101-Kilobase-Pair Megaplasmid pKB1, Isolated from the Rubber-Degrading Bacterium Gordonia westfalica Kb1

PubMed Central

Bröker, Daniel; Arenskötter, Matthias; Legatzki, Antje; Nies, Dietrich H.; Steinbüchel, Alexander

2004-01-01

The complete sequence of the circular 101,016-bp megaplasmid pKB1 from the cis-1,4-polyisoprene-degrading bacterium Gordonia westfalica Kb1, which represents the first described extrachromosomal DNA of a member of this genus, was determined. Plasmid pKB1 harbors 105 open reading frames. The predicted products of 46 of these are significantly related to proteins of known function. Plasmid pKB1 is organized into three functional regions that are flanked by insertion sequence (IS) elements: (i) a replication and putative partitioning region, (ii) a putative metabolic region, and (iii) a large putative conjugative transfer region, which is interrupted by an additional IS element. Southern hybridization experiments revealed the presence of another copy of this conjugational transfer region on the bacterial chromosome. The origin of replication (oriV) of pKB1 was identified and used for construction of Escherichia coli-Gordonia shuttle vectors, which was also suitable for several other Gordonia species and related genera. The metabolic region included the heavy-metal resistance gene cadA, encoding a P-type ATPase. Expression of cadA in E. coli mediated resistance to cadmium, but not to zinc, and decreased the cellular content of cadmium in this host. When G. westfalica strain Kb1 was cured of plasmid pKB1, the resulting derivative strains exhibited slightly decreased cadmium resistance. Furthermore, they had lost the ability to use isoprene rubber as a sole source of carbon and energy, suggesting that genes essential for rubber degradation are encoded by pKB1. PMID:14679241

Role of the X-linked gene GPR174 in autoimmune Addison's disease.

PubMed

Napier, C; Mitchell, A L; Gan, E; Wilson, I; Pearce, S H S

2015-01-01

Autoimmune endocrinopathies demonstrate a profound gender bias, but the reasons for this remain obscure. The 1000 genes on the X chromosome are likely to be implicated in this inherent susceptibility; various theories, including skewed X chromosome inactivation and fetal microchimerism, have been proposed. GPR174 is an Xq21 putative purinergic receptor that is widely expressed in lymphoid tissues. A single-nucleotide polymorphism, rs3827440, encoding Ser162Pro, has recently been associated with Graves' disease in Chinese and Polish populations, suggesting a role of this X chromosome gene in autoimmune disease. We investigated the role of rs3827440 in a UK cohort of patients with autoimmune Addison's disease (AAD). Samples from 286 AAD cases and 288 healthy controls were genotyped using TaqMan single-nucleotide polymorphism genotyping assays (C_25954273_10) on the Applied Biosystems 7900HT Fast real-time PCR system. Using a dominant (present/absent) model, the serine-encoding T allele of rs3827440 was present in 189 of 286 AAD patients (66%) compared with 132 of 288 unaffected controls (46%) [P = .010, odds ratio 1.80 (5%-95% confidence interval 1.22-2.67)]. An allele dosage model found a significant excess of the T allele in AAD patients compared with controls [P = .03, odds ratio 1.34 (5%-95% confidence interval 1.07-1.67)]. We have demonstrated a significant association of this X chromosome-encoded immunoreceptor with AAD for the first time. This X-linked gene could have a more generalized role in autoimmunity pathogenesis: G protein-coupled receptors are promising drugable targets, and further work to elucidate the functional role of GPR174 is now warranted.

Distinct Bacteriophages Encoding Panton-Valentine Leukocidin (PVL) among International Methicillin-Resistant Staphylococcus aureus Clones Harboring PVL▿

PubMed Central

Boakes, E.; Kearns, A. M.; Ganner, M.; Perry, C.; Hill, R. L.; Ellington, M. J.

2011-01-01

Genetically diverse community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) can harbor a bacteriophage encoding Panton-Valentine leukocidin (PVL) lysogenized into its chromosome (prophage). Six PVL phages (ΦPVL, Φ108PVL, ΦSLT, ΦSa2MW, ΦSa2USA, and ΦSa2958) are known, and single-nucleotide polymorphisms (SNPs) in the PVL genes have been reported. We sought to determine the distribution of lysogenized PVL phages among MRSA strains with PVL (PVL-MRSA strains), the PVL gene sequences, and the chromosomal phage insertion sites in 114 isolates comprising nine clones of PVL-MRSA that were selected for maximal underlying genetic diversity. The six PVL phages were identified by PCR; ΦSa2USA was present in the highest number of different lineages (multilocus sequence type clonal complex 1 [CC1], CC5, CC8, and sequence type 93 [ST93]) (n = 37 isolates). Analysis of 92 isolates confirmed that PVL phages inserted into the same chromosomal insertion locus in CC22, -30, and -80 but in a different locus in isolates of CC1, -5, -8, -59, and -88 and ST93 (and CC22 in two isolates). Within the two different loci, specific attachment motifs were found in all cases, although some limited inter- and intralineage sequence variation occurred. Overall, lineage-specific relationships between the PVL phage, the genes that encode the toxin, and the position at which the phage inserts into the host chromosome were identified. These analyses provide important insights into the microepidemiology of PVL-MRSA, will prove a valuable adjunct in outbreak investigation, and may help predict the emergence of new strains. PMID:21106787

Chromosomally Encoded mcr-5 in Colistin non-susceptible Pseudomonas aeruginosa.

PubMed

Snesrud, Erik; Maybank, Rosslyn; Kwak, Yoon I; Jones, Anthony R; Hinkle, Mary K; Mc Gann, Patrick

2018-05-29

Whole genome sequencing (WGS) of historical Pseudomonas aeruginosa clinical isolates identified a chromosomal copy of mcr-5 within a Tn 3 -like transposon in P. aeruginosa MRSN 12280. The isolate was non-susceptible to colistin by broth microdilution and genome analysis revealed no mutations known to confer colistin resistance. To the best of our knowledge, this is the first report of mcr in colistin non-susceptible P. aeruginosa .

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

Taguchi, Takahiro; Testa, J.R.; Mitcham, J.L.

This report describes the localization of the the TIL gene to human chromosome 4p14 using fluorescence in situ hybridization. This gene encodes a protein which is related to the Drosophila transmembrane receptor Toll and the mammalian interleukin-1 receptor, which share similarities in structure and function. The Drosophila gene is also important during embryonic development, which makes TIL a candidate locus for human congenital malformations that are genetically linked to human chromosome 4. 17 refs., 1 fig.

Duplication and partitioning in evolution and function of homoeologous Q loci governing domestication characters in polyploid wheat

USDA-ARS?s Scientific Manuscript database

The Q gene encodes an AP2-like transcription factor that played an important role in domestication of polyploid wheat. The chromosome 5A Q alleles (5AQ and 5Aq) have been well studied, but much less is known about the q alleles on wheat homoeologous chromosomes 5B (5Bq) and 5D (5Dq). We investigated...

Directional selection has shaped the oral jaws of Lake Malawi cichlid fishes.

PubMed

Albertson, R Craig; Streelman, J Todd; Kocher, Thomas D

2003-04-29

East African cichlid fishes represent one of the most striking examples of rapid and convergent evolutionary radiation among vertebrates. Models of ecological speciation would suggest that functional divergence in feeding morphology has contributed to the origin and maintenance of cichlid species diversity. However, definitive evidence for the action of natural selection has been missing. Here we use quantitative genetics to identify regions of the cichlid genome responsible for functionally important shape differences in the oral jaw apparatus. The consistent direction of effects for individual quantitative trait loci suggest that cichlid jaws and teeth evolved in response to strong, divergent selection. Moreover, several chromosomal regions contain a disproportionate number of quantitative trait loci, indicating a prominent role for pleiotropy or genetic linkage in the divergence of this character complex. Of particular interest are genomic intervals with concerted effects on both the length and height of the lower jaw. Coordinated changes in this area of the oral jaw apparatus are predicted to have direct consequences for the speed and strength of jaw movement. Taken together, our results imply that the rapid and replicative nature of cichlid trophic evolution is the result of directional selection on chromosomal packages that encode functionally linked aspects of the craniofacial skeleton.

Basic leucine zipper family in barley: genome-wide characterization of members and expression analysis.

PubMed

Pourabed, Ehsan; Ghane Golmohamadi, Farzan; Soleymani Monfared, Peyman; Razavi, Seyed Morteza; Shobbar, Zahra-Sadat

2015-01-01

The basic leucine zipper (bZIP) family is one of the largest and most diverse transcription factors in eukaryotes participating in many essential plant processes. We identified 141 bZIP proteins encoded by 89 genes from the Hordeum vulgare genome. HvbZIPs were classified into 11 groups based on their DNA-binding motif. Amino acid sequence alignment of the HvbZIPs basic-hinge regions revealed some highly conserved residues within each group. The leucine zipper heptads were analyzed predicting their dimerization properties. 34 conserved motifs were identified outside the bZIP domain. Phylogenetic analysis indicated that major diversification within the bZIP family predated the monocot/dicot divergence, although intra-species duplication and parallel evolution seems to be occurred afterward. Localization of HvbZIPs on the barley chromosomes revealed that different groups have been distributed on seven chromosomes of barley. Six types of intron pattern were detected within the basic-hinge regions. Most of the detected cis-elements in the promoter and UTR sequences were involved in seed development or abiotic stress response. Microarray data analysis revealed differential expression pattern of HvbZIPs in response to ABA treatment, drought, and cold stresses and during barley grain development and germination. This information would be helpful for functional characterization of bZIP transcription factors in barley.

A Cytoplasmic Dynein Heavy Chain Is Required for Oscillatory Nuclear Movement of Meiotic Prophase and Efficient Meiotic Recombination in Fission Yeast

PubMed Central

Yamamoto, Ayumu; West, Robert R.; McIntosh, J. Richard; Hiraoka, Yasushi

1999-01-01

Meiotic recombination requires pairing of homologous chromosomes, the mechanisms of which remain largely unknown. When pairing occurs during meiotic prophase in fission yeast, the nucleus oscillates between the cell poles driven by astral microtubules. During these oscillations, the telomeres are clustered at the spindle pole body (SPB), located at the leading edge of the moving nucleus and the rest of each chromosome dangles behind. Here, we show that the oscillatory nuclear movement of meiotic prophase is dependent on cytoplasmic dynein. We have cloned the gene encoding a cytoplasmic dynein heavy chain of fission yeast. Most of the cells disrupted for the gene show no gross defect during mitosis and complete meiosis to form four viable spores, but they lack the nuclear movements of meiotic prophase. Thus, the dynein heavy chain is required for these oscillatory movements. Consistent with its essential role in such nuclear movement, dynein heavy chain tagged with green fluorescent protein (GFP) is localized at astral microtubules and the SPB during the movements. In dynein-disrupted cells, meiotic recombination is significantly reduced, indicating that the dynein function is also required for efficient meiotic recombination. In accordance with the reduced recombination, which leads to reduced crossing over, chromosome missegregation is increased in the mutant. Moreover, both the formation of a single cluster of centromeres and the colocalization of homologous regions on a pair of homologous chromosomes are significantly inhibited in the mutant. These results strongly suggest that the dynein-driven nuclear movements of meiotic prophase are necessary for efficient pairing of homologous chromosomes in fission yeast, which in turn promotes efficient meiotic recombination. PMID:10366596

Characterization of a New Multigene Family Encoding Isomaltases in the Yeast Saccharomyces cerevisiae, the IMA Family*

PubMed Central

Teste, Marie-Ange; François, Jean Marie; Parrou, Jean-Luc

2010-01-01

It has been known for a long time that the yeast Saccharomyces cerevisiae can assimilate α-methylglucopyranoside and isomaltose. We here report the identification of 5 genes (YGR287c, YIL172c, YJL216c, YJL221c and YOL157c), which, similar to the SUCx, MALx, or HXTx multigene families, are located in the subtelomeric regions of different chromosomes. They share high nucleotide sequence identities between themselves (66–100%) and with the MALx2 genes (63–74%). Comparison of their amino acid sequences underlined a substitution of threonine by valine in region II, one of the four highly conserved regions of the α-glucosidase family. This change was previously shown to be sufficient to discriminate α-1,4- to α-1,6-glucosidase activity in YGR287c (Yamamoto, K., Nakayama, A., Yamamoto, Y., and Tabata, S. (2004) Eur. J. Biochem. 271, 3414–3420). We showed that each of these five genes encodes a protein with α-glucosidase activity on isomaltose, and we therefore renamed these genes IMA1 to IMA5 for IsoMAltase. Our results also illustrated that sequence polymorphisms among this family led to interesting variability of gene expression patterns and of catalytic efficiencies on different substrates, which altogether should account for the absence of functional redundancy for growth on isomaltose. Indeed, deletion studies revealed that IMA1/YGR287c encodes the major isomaltase and that growth on isomaltose required the presence of AGT1, which encodes an α-glucoside transporter. Expressions of IMA1 and IMA5/YJL216c were strongly induced by maltose, isomaltose, and α-methylglucopyranoside, in accordance with their regulation by the Malx3p-transcription system. The physiological relevance of this IMAx multigene family in S. cerevisiae is discussed. PMID:20562106

Highly distinct chromosomal structures in cowpea (Vigna unguiculata), as revealed by molecular cytogenetic analysis.

PubMed

Iwata-Otsubo, Aiko; Lin, Jer-Young; Gill, Navdeep; Jackson, Scott A

2016-05-01

Cowpea (Vigna unguiculata (L.) Walp) is an important legume, particularly in developing countries. However, little is known about its genome or chromosome structure. We used molecular cytogenetics to characterize the structure of pachytene chromosomes to advance our knowledge of chromosome and genome organization of cowpea. Our data showed that cowpea has highly distinct chromosomal structures that are cytologically visible as brightly DAPI-stained heterochromatic regions. Analysis of the repetitive fraction of the cowpea genome present at centromeric and pericentromeric regions confirmed that two retrotransposons are major components of pericentromeric regions and that a 455-bp tandem repeat is found at seven out of 11 centromere pairs in cowpea. These repeats likely evolved after the divergence of cowpea from common bean and form chromosomal structure unique to cowpea. The integration of cowpea genetic and physical chromosome maps reveals potential regions of suppressed recombination due to condensed heterochromatin and a lack of pairing in a few chromosomal termini. This study provides fundamental knowledge on cowpea chromosome structure and molecular cytogenetics tools for further chromosome studies.

Evolutionary pathway to increased virulence and epidemic group A Streptococcus disease derived from 3,615 genome sequences.

PubMed

Nasser, Waleed; Beres, Stephen B; Olsen, Randall J; Dean, Melissa A; Rice, Kelsey A; Long, S Wesley; Kristinsson, Karl G; Gottfredsson, Magnus; Vuopio, Jaana; Raisanen, Kati; Caugant, Dominique A; Steinbakk, Martin; Low, Donald E; McGeer, Allison; Darenberg, Jessica; Henriques-Normark, Birgitta; Van Beneden, Chris A; Hoffmann, Steen; Musser, James M

2014-04-29

We sequenced the genomes of 3,615 strains of serotype Emm protein 1 (M1) group A Streptococcus to unravel the nature and timing of molecular events contributing to the emergence, dissemination, and genetic diversification of an unusually virulent clone that now causes epidemic human infections worldwide. We discovered that the contemporary epidemic clone emerged in stepwise fashion from a precursor cell that first contained the phage encoding an extracellular DNase virulence factor (streptococcal DNase D2, SdaD2) and subsequently acquired the phage encoding the SpeA1 variant of the streptococcal pyrogenic exotoxin A superantigen. The SpeA2 toxin variant evolved from SpeA1 by a single-nucleotide change in the M1 progenitor strain before acquisition by horizontal gene transfer of a large chromosomal region encoding secreted toxins NAD(+)-glycohydrolase and streptolysin O. Acquisition of this 36-kb region in the early 1980s into just one cell containing the phage-encoded sdaD2 and speA2 genes was the final major molecular event preceding the emergence and rapid intercontinental spread of the contemporary epidemic clone. Thus, we resolve a decades-old controversy about the type and sequence of genomic alterations that produced this explosive epidemic. Analysis of comprehensive, population-based contemporary invasive strains from seven countries identified strong patterns of temporal population structure. Compared with a preepidemic reference strain, the contemporary clone is significantly more virulent in nonhuman primate models of pharyngitis and necrotizing fasciitis. A key finding is that the molecular evolutionary events transpiring in just one bacterial cell ultimately have produced millions of human infections worldwide.

Evolutionary pathway to increased virulence and epidemic group A Streptococcus disease derived from 3,615 genome sequences

PubMed Central

Nasser, Waleed; Beres, Stephen B.; Olsen, Randall J.; Dean, Melissa A.; Rice, Kelsey A.; Long, S. Wesley; Kristinsson, Karl G.; Gottfredsson, Magnus; Vuopio, Jaana; Raisanen, Kati; Caugant, Dominique A.; Steinbakk, Martin; Low, Donald E.; McGeer, Allison; Darenberg, Jessica; Henriques-Normark, Birgitta; Van Beneden, Chris A.; Hoffmann, Steen; Musser, James M.

2014-01-01

We sequenced the genomes of 3,615 strains of serotype Emm protein 1 (M1) group A Streptococcus to unravel the nature and timing of molecular events contributing to the emergence, dissemination, and genetic diversification of an unusually virulent clone that now causes epidemic human infections worldwide. We discovered that the contemporary epidemic clone emerged in stepwise fashion from a precursor cell that first contained the phage encoding an extracellular DNase virulence factor (streptococcal DNase D2, SdaD2) and subsequently acquired the phage encoding the SpeA1 variant of the streptococcal pyrogenic exotoxin A superantigen. The SpeA2 toxin variant evolved from SpeA1 by a single-nucleotide change in the M1 progenitor strain before acquisition by horizontal gene transfer of a large chromosomal region encoding secreted toxins NAD+-glycohydrolase and streptolysin O. Acquisition of this 36-kb region in the early 1980s into just one cell containing the phage-encoded sdaD2 and speA2 genes was the final major molecular event preceding the emergence and rapid intercontinental spread of the contemporary epidemic clone. Thus, we resolve a decades-old controversy about the type and sequence of genomic alterations that produced this explosive epidemic. Analysis of comprehensive, population-based contemporary invasive strains from seven countries identified strong patterns of temporal population structure. Compared with a preepidemic reference strain, the contemporary clone is significantly more virulent in nonhuman primate models of pharyngitis and necrotizing fasciitis. A key finding is that the molecular evolutionary events transpiring in just one bacterial cell ultimately have produced millions of human infections worldwide. PMID:24733896

Stable chromosome condensation revealed by chromosome conformation capture

PubMed Central

Eagen, Kyle P.; Hartl, Tom A.; Kornberg, Roger D.

2015-01-01

SUMMARY Chemical cross-linking and DNA sequencing have revealed regions of intra-chromosomal interaction, referred to as topologically associating domains (TADs), interspersed with regions of little or no interaction, in interphase nuclei. We find that TADs and the regions between them correspond with the bands and interbands of polytene chromosomes of Drosophila. We further establish the conservation of TADs between polytene and diploid cells of Drosophila. From direct measurements on light micrographs of polytene chromosomes, we then deduce the states of chromatin folding in the diploid cell nucleus. Two states of folding, fully extended fibers containing regulatory regions and promoters, and fibers condensed up to ten-fold containing coding regions of active genes, constitute the euchromatin of the nuclear interior. Chromatin fibers condensed up to 30-fold, containing coding regions of inactive genes, represent the heterochromatin of the nuclear periphery. A convergence of molecular analysis with direct observation thus reveals the architecture of interphase chromosomes. PMID:26544940

Protannotator: a semiautomated pipeline for chromosome-wise functional annotation of the "missing" human proteome.

PubMed

Islam, Mohammad T; Garg, Gagan; Hancock, William S; Risk, Brian A; Baker, Mark S; Ranganathan, Shoba

2014-01-03

The chromosome-centric human proteome project (C-HPP) aims to define the complete set of proteins encoded in each human chromosome. The neXtProt database (September 2013) lists 20,128 proteins for the human proteome, of which 3831 human proteins (∼19%) are considered "missing" according to the standard metrics table (released September 27, 2013). In support of the C-HPP initiative, we have extended the annotation strategy developed for human chromosome 7 "missing" proteins into a semiautomated pipeline to functionally annotate the "missing" human proteome. This pipeline integrates a suite of bioinformatics analysis and annotation software tools to identify homologues and map putative functional signatures, gene ontology, and biochemical pathways. From sequential BLAST searches, we have primarily identified homologues from reviewed nonhuman mammalian proteins with protein evidence for 1271 (33.2%) "missing" proteins, followed by 703 (18.4%) homologues from reviewed nonhuman mammalian proteins and subsequently 564 (14.7%) homologues from reviewed human proteins. Functional annotations for 1945 (50.8%) "missing" proteins were also determined. To accelerate the identification of "missing" proteins from proteomics studies, we generated proteotypic peptides in silico. Matching these proteotypic peptides to ENCODE proteogenomic data resulted in proteomic evidence for 107 (2.8%) of the 3831 "missing proteins, while evidence from a recent membrane proteomic study supported the existence for another 15 "missing" proteins. The chromosome-wise functional annotation of all "missing" proteins is freely available to the scientific community through our web server (http://biolinfo.org/protannotator).

Glioblastoma adaptation traced through decline of an IDH1 clonal driver and macro-evolution of a double-minute chromosome.

PubMed

Favero, F; McGranahan, N; Salm, M; Birkbak, N J; Sanborn, J Z; Benz, S C; Becq, J; Peden, J F; Kingsbury, Z; Grocok, R J; Humphray, S; Bentley, D; Spencer-Dene, B; Gutteridge, A; Brada, M; Roger, S; Dietrich, P-Y; Forshew, T; Gerlinger, M; Rowan, A; Stamp, G; Eklund, A C; Szallasi, Z; Swanton, C

2015-05-01

Glioblastoma (GBM) is the most common malignant brain cancer occurring in adults, and is associated with dismal outcome and few therapeutic options. GBM has been shown to predominantly disrupt three core pathways through somatic aberrations, rendering it ideal for precision medicine approaches. We describe a 35-year-old female patient with recurrent GBM following surgical removal of the primary tumour, adjuvant treatment with temozolomide and a 3-year disease-free period. Rapid whole-genome sequencing (WGS) of three separate tumour regions at recurrence was carried out and interpreted relative to WGS of two regions of the primary tumour. We found extensive mutational and copy-number heterogeneity within the primary tumour. We identified a TP53 mutation and two focal amplifications involving PDGFRA, KIT and CDK4, on chromosomes 4 and 12. A clonal IDH1 R132H mutation in the primary, a known GBM driver event, was detectable at only very low frequency in the recurrent tumour. After sub-clonal diversification, evidence was found for a whole-genome doubling event and a translocation between the amplified regions of PDGFRA, KIT and CDK4, encoded within a double-minute chromosome also incorporating miR26a-2. The WGS analysis uncovered progressive evolution of the double-minute chromosome converging on the KIT/PDGFRA/PI3K/mTOR axis, superseding the IDH1 mutation in dominance in a mutually exclusive manner at recurrence, consequently the patient was treated with imatinib. Despite rapid sequencing and cancer genome-guided therapy against amplified oncogenes, the disease progressed, and the patient died shortly after. This case sheds light on the dynamic evolution of a GBM tumour, defining the origins of the lethal sub-clone, the macro-evolutionary genomic events dominating the disease at recurrence and the loss of a clonal driver. Even in the era of rapid WGS analysis, cases such as this illustrate the significant hurdles for precision medicine success. © The Author 2015. Published by Oxford University Press on behalf of the European Society for Medical Oncology.

Chromosome End Repair and Genome Stability in Plasmodium falciparum.

PubMed

Calhoun, Susannah F; Reed, Jake; Alexander, Noah; Mason, Christopher E; Deitsch, Kirk W; Kirkman, Laura A

2017-08-08

The human malaria parasite Plasmodium falciparum replicates within circulating red blood cells, where it is subjected to conditions that frequently cause DNA damage. The repair of DNA double-stranded breaks (DSBs) is thought to rely almost exclusively on homologous recombination (HR), due to a lack of efficient nonhomologous end joining. However, given that the parasite is haploid during this stage of its life cycle, the mechanisms involved in maintaining genome stability are poorly understood. Of particular interest are the subtelomeric regions of the chromosomes, which contain the majority of the multicopy variant antigen-encoding genes responsible for virulence and disease severity. Here, we show that parasites utilize a competitive balance between de novo telomere addition, also called "telomere healing," and HR to stabilize chromosome ends. Products of both repair pathways were observed in response to DSBs that occurred spontaneously during routine in vitro culture or resulted from experimentally induced DSBs, demonstrating that both pathways are active in repairing DSBs within subtelomeric regions and that the pathway utilized was determined by the DNA sequences immediately surrounding the break. In combination, these two repair pathways enable parasites to efficiently maintain chromosome stability while also contributing to the generation of genetic diversity. IMPORTANCE Malaria is a major global health threat, causing approximately 430,000 deaths annually. This mosquito-transmitted disease is caused by Plasmodium parasites, with infection with the species Plasmodium falciparum being the most lethal. Mechanisms underlying DNA repair and maintenance of genome integrity in P. falciparum are not well understood and represent a gap in our understanding of how parasites survive the hostile environment of their vertebrate and insect hosts. Our work examines DNA repair in real time by using single-molecule real-time (SMRT) sequencing focused on the subtelomeric regions of the genome that harbor the multicopy gene families important for virulence and the maintenance of infection. We show that parasites utilize two competing molecular mechanisms to repair double-strand breaks, homologous recombination and de novo telomere addition, with the pathway used being determined by the surrounding DNA sequence. In combination, these two pathways balance the need to maintain genome stability with the selective advantage of generating antigenic diversity. Copyright © 2017 Calhoun et al.

Destabilized SMC5/6 complex leads to chromosome breakage syndrome with severe lung disease

PubMed Central

van der Crabben, Saskia N.; Hennus, Marije P.; McGregor, Grant A.; Ritter, Deborah I.; Nagamani, Sandesh C.S.; Wells, Owen S.; Harakalova, Magdalena; Chinn, Ivan K.; Alt, Aaron; Vondrova, Lucie; Hochstenbach, Ron; van Montfrans, Joris M.; Terheggen-Lagro, Suzanne W.; van Lieshout, Stef; van Roosmalen, Markus J.; Renkens, Ivo; Duran, Karen; Nijman, Isaac J.; Kloosterman, Wigard P.; Hennekam, Eric; van Hasselt, Peter M.; Wheeler, David A.; Palecek, Jan J.; Lehmann, Alan R.; Oliver, Antony W.; Pearl, Laurence H.; Plon, Sharon E.; Murray, Johanne M.

2016-01-01

The structural maintenance of chromosomes (SMC) family of proteins supports mitotic proliferation, meiosis, and DNA repair to control genomic stability. Impairments in chromosome maintenance are linked to rare chromosome breakage disorders. Here, we have identified a chromosome breakage syndrome associated with severe lung disease in early childhood. Four children from two unrelated kindreds died of severe pulmonary disease during infancy following viral pneumonia with evidence of combined T and B cell immunodeficiency. Whole exome sequencing revealed biallelic missense mutations in the NSMCE3 (also known as NDNL2) gene, which encodes a subunit of the SMC5/6 complex that is essential for DNA damage response and chromosome segregation. The NSMCE3 mutations disrupted interactions within the SMC5/6 complex, leading to destabilization of the complex. Patient cells showed chromosome rearrangements, micronuclei, sensitivity to replication stress and DNA damage, and defective homologous recombination. This work associates missense mutations in NSMCE3 with an autosomal recessive chromosome breakage syndrome that leads to defective T and B cell function and acute respiratory distress syndrome in early childhood. PMID:27427983

Destabilized SMC5/6 complex leads to chromosome breakage syndrome with severe lung disease.

PubMed

van der Crabben, Saskia N; Hennus, Marije P; McGregor, Grant A; Ritter, Deborah I; Nagamani, Sandesh C S; Wells, Owen S; Harakalova, Magdalena; Chinn, Ivan K; Alt, Aaron; Vondrova, Lucie; Hochstenbach, Ron; van Montfrans, Joris M; Terheggen-Lagro, Suzanne W; van Lieshout, Stef; van Roosmalen, Markus J; Renkens, Ivo; Duran, Karen; Nijman, Isaac J; Kloosterman, Wigard P; Hennekam, Eric; Orange, Jordan S; van Hasselt, Peter M; Wheeler, David A; Palecek, Jan J; Lehmann, Alan R; Oliver, Antony W; Pearl, Laurence H; Plon, Sharon E; Murray, Johanne M; van Haaften, Gijs

2016-08-01

The structural maintenance of chromosomes (SMC) family of proteins supports mitotic proliferation, meiosis, and DNA repair to control genomic stability. Impairments in chromosome maintenance are linked to rare chromosome breakage disorders. Here, we have identified a chromosome breakage syndrome associated with severe lung disease in early childhood. Four children from two unrelated kindreds died of severe pulmonary disease during infancy following viral pneumonia with evidence of combined T and B cell immunodeficiency. Whole exome sequencing revealed biallelic missense mutations in the NSMCE3 (also known as NDNL2) gene, which encodes a subunit of the SMC5/6 complex that is essential for DNA damage response and chromosome segregation. The NSMCE3 mutations disrupted interactions within the SMC5/6 complex, leading to destabilization of the complex. Patient cells showed chromosome rearrangements, micronuclei, sensitivity to replication stress and DNA damage, and defective homologous recombination. This work associates missense mutations in NSMCE3 with an autosomal recessive chromosome breakage syndrome that leads to defective T and B cell function and acute respiratory distress syndrome in early childhood.

Achilles, a New Family of Transcriptionally Active Retrotransposons from the Olive Fruit Fly, with Y Chromosome Preferential Distribution

PubMed Central

Tsoumani, Konstantina T.; Drosopoulou, Elena; Bourtzis, Kostas; Gariou-Papalexiou, Aggeliki; Mavragani-Tsipidou, Penelope; Zacharopoulou, Antigone; Mathiopoulos, Kostas D.

2015-01-01

Sex chromosomes have many unusual features relative to autosomes. The in depth exploration of their structure will improve our understanding of their origin and divergence (degeneration) as well as the evolution of genetic sex determination pathways which, most often are attributed to them. In Tephritids, the structure of Y chromosome, where the male-determining factor M is localized, is largely unexplored and limited data concerning its sequence content and evolution are available. In order to get insight into the structure and organization of the Y chromosome of the major olive insect pest, the olive fly Bactrocera oleae, we characterized sequences from a Pulse Field Gel Electrophoresis (PFGE)-isolated Y chromosome. Here, we report the discovery of the first olive fly LTR retrotransposon with increased presence on the Y chromosome. The element belongs to the BEL-Pao superfamily, however, its sequence comparison with the other members of the superfamily suggests that it constitutes a new family that we termed Achilles. Its ~7.5 kb sequence consists of the 5’LTR, the 5’non-coding sequence and the open reading frame (ORF), which encodes the polyprotein Gag-Pol. In situ hybridization to the B. oleae polytene chromosomes showed that Achilles is distributed in discrete bands dispersed on all five autosomes, in all centromeric regions and in the granular heterochromatic network corresponding to the mitotic sex chromosomes. The between sexes comparison revealed a variation in Achilles copy number, with male flies possessing 5–10 copies more than female (CI range: 18–38 and 12–33 copies respectively per genome). The examination of its transcriptional activity demonstrated the presence of at least one intact active copy in the genome, showing a differential level of expression between sexes as well as during embryonic development. The higher expression was detected in male germline tissues (testes). Moreover, the presence of Achilles-like elements in different species of the Tephritidae family suggests an ancient origin of this element. PMID:26398504

A comparative genomic hybridization study in a 46,XX male.

PubMed

Rigola, M Angels; Carrera, Marta; Ribas, Isabel; Egozcue, Josep; Miró, Rosa; Fuster, Carme

2002-07-01

To identify Y chromosome material in an azoospermic male with an XX karyotype. Case report. Faculty of medicine and Centro de Patologia Celular (CPC) medical center. A 33-year-old man with infertility. G-banding, fluorescence in situ hybridization (FISH), polymerase chain reaction (PCR), and comparative genomic hybridization (CGH). FISH for X and Y chromosomes, PCR for the SRYgene and amelogenin gene in the Xp (AMGX) and (AMGY), and losses or gains with CGH. FISH analysis using X and Y chromosome-specific probes showed an X chromosome containing Y chromosome sequences on the top of the short arm; this Y chromosome region was not visible by conventional cytogenetic analysis. PCR amplification of DNA showed the presence of the sex-determining region of the Y chromosome (SRY) and the amelogenin gene in the pseudoautosomal boundary of the X chromosome (AMGX). CGH confirmed the presence of the chromosome region Yp11.2-pter and detected the presence of the two otherwise normal X chromosomes. The two Xpter (XPAR1) pseudoautosomal regions present in this XX male suggest the need to reevaluate XX males using CGH and PCR to characterize the clinical variability in XX males due to genes other than those located on the Y chromosome.

TF1, the bacteriophage SPO1-encoded type II DNA-binding protein, is essential for viral multiplication.

PubMed

Sayre, M H; Geiduschek, E P

1988-09-01

The lytic Bacillus subtilis bacteriophage SPO1 encodes an abundant, 99-amino-acid type II DNA-binding protein, transcription factor 1 (TF1). TF1 is special in this family of procaryotic chromatin-forming proteins in its preference for hydroxymethyluracil-containing DNA, such as SPO1 DNA, and in binding with high affinity to specific sites in the SPO1 chromosome. We constructed recessive null alleles of the TF1 gene and introduced them into SPO1 chromosomes. Segregation analysis with partially diploid phage heterozygous for TF1 showed that phage bearing only these null alleles was inviable. Deletion of the nine C-proximal amino acids of TF1 prohibited phage multiplication in vivo and abolished its site-specific DNA-binding activity in vitro.

A Portrait of Ribosomal DNA Contacts with Hi-C Reveals 5S and 45S rDNA Anchoring Points in the Folded Human Genome.

PubMed

Yu, Shoukai; Lemos, Bernardo

2016-12-31

Ribosomal RNAs (rRNAs) account for >60% of all RNAs in eukaryotic cells and are encoded in the ribosomal DNA (rDNA) arrays. The rRNAs are produced from two sets of loci: the 5S rDNA array resides exclusively on human chromosome 1, whereas the 45S rDNA array resides on the short arm of five human acrocentric chromosomes. The 45S rDNA gives origin to the nucleolus, the nuclear organelle that is the site of ribosome biogenesis. Intriguingly, 5S and 45S rDNA arrays exhibit correlated copy number variation in lymphoblastoid cells (LCLs). Here we examined the genomic architecture and repeat content of the 5S and 45S rDNA arrays in multiple human genome assemblies (including PacBio MHAP assembly) and ascertained contacts between the rDNA arrays and the rest of the genome using Hi-C datasets from two human cell lines (erythroleukemia K562 and lymphoblastoid cells). Our analyses revealed that 5S and 45S arrays each have thousands of contacts in the folded genome, with rDNA-associated regions and genes dispersed across all chromosomes. The rDNA contact map displayed conserved and disparate features between two cell lines, and pointed to specific chromosomes, genomic regions, and genes with evidence of spatial proximity to the rDNA arrays; the data also showed a lack of direct physical interaction between the 5S and 45S rDNA arrays. Finally, the analysis identified an intriguing organization in the 5S array with Alu and 5S elements adjacent to one another and organized in opposite orientation along the array. Portraits of genome folding centered on the ribosomal DNA array could help understand the emergence of concerted variation, the control of 5S and 45S expression, as well as provide insights into an organelle that contributes to the spatial localization of human chromosomes during interphase. © The Author(s) 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Nuclear-Cytoplasmic Conflict in Pea (Pisum sativum L.) Is Associated with Nuclear and Plastidic Candidate Genes Encoding Acetyl-CoA Carboxylase Subunits

PubMed Central

Bogdanova, Vera S.; Zaytseva, Olga O.; Mglinets, Anatoliy V.; Shatskaya, Natalia V.; Kosterin, Oleg E.; Vasiliev, Gennadiy V.

2015-01-01

In crosses of wild and cultivated peas (Pisum sativum L.), nuclear-cytoplasmic incompatibility frequently occurs manifested as decreased pollen fertility, male gametophyte lethality, sporophyte lethality. High-throughput sequencing of plastid genomes of one cultivated and four wild pea accessions differing in cross-compatibility was performed. Candidate genes for involvement in the nuclear-plastid conflict were searched in the reconstructed plastid genomes. In the annotated Medicago truncatula genome, nuclear candidate genes were searched in the portion syntenic to the pea chromosome region known to harbor a locus involved in the conflict. In the plastid genomes, a substantial variability of the accD locus represented by nucleotide substitutions and indels was found to correspond to the pattern of cross-compatibility among the accessions analyzed. Amino acid substitutions in the polypeptides encoded by the alleles of a nuclear locus, designated as Bccp3, with a complementary function to accD, fitted the compatibility pattern. The accD locus in the plastid genome encoding beta subunit of the carboxyltransferase of acetyl-coA carboxylase and the nuclear locus Bccp3 encoding biotin carboxyl carrier protein of the same multi-subunit enzyme were nominated as candidate genes for main contribution to nuclear-cytoplasmic incompatibility in peas. Existence of another nuclear locus involved in the accD-mediated conflict is hypothesized. PMID:25789472

Molecular and Mutational Analysis of a Gelsolin-Family Member Encoded by the Flightless I Gene of Drosophila Melanogaster

PubMed Central

de-Couet, H. G.; Fong, KSK.; Weeds, A. G.; McLaughlin, P. J.; Miklos, GLG.

1995-01-01

The flightless locus of Drosophila melanogaster has been analyzed at the genetic, molecular, ultrastructural and comparative crystallographic levels. The gene encodes a single transcript encoding a protein consisting of a leucine-rich amino terminal half and a carboxyterminal half with high sequence similarity to gelsolin. We determined the genomic sequence of the flightless landscape, the breakpoints of four chromosomal rearrangements, and the molecular lesions in two lethal and two viable alleles of the gene. The two alleles that lead to flight muscle abnormalities encode mutant proteins exhibiting amino acid replacements within the S1-like domain of their gelsolin-like region. Furthermore, the deduced intronexon structure of the D. melanogaster gene has been compared with that of the Caenorhabditis elegans homologue. Furthermore, the sequence similarities of the flightless protein with gelsolin allow it to be evaluated in the context of the published crystallographic structure of the S1 domain of gelsolin. Amino acids considered essential for the structural integrity of the core are found to be highly conserved in the predicted flightless protein. Some of the residues considered essential for actin and calcium binding in gelsolin S1 and villin V1 are also well conserved. These data are discussed in light of the phenotypic characteristics of the mutants and the putative functions of the protein. PMID:8582612

Identification of functional elements and regulatory circuits by Drosophila modENCODE

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

Roy, Sushmita; Ernst, Jason; Kharchenko, Peter V.

2010-12-22

To gain insight into how genomic information is translated into cellular and developmental programs, the Drosophila model organism Encyclopedia of DNA Elements (modENCODE) project is comprehensively mapping transcripts, histone modifications, chromosomal proteins, transcription factors, replication proteins and intermediates, and nucleosome properties across a developmental time course and in multiple cell lines. We have generated more than 700 data sets and discovered protein-coding, noncoding, RNA regulatory, replication, and chromatin elements, more than tripling the annotated portion of the Drosophila genome. Correlated activity patterns of these elements reveal a functional regulatory network, which predicts putative new functions for genes, reveals stage- andmore » tissue-specific regulators, and enables gene-expression prediction. Our results provide a foundation for directed experimental and computational studies in Drosophila and related species and also a model for systematic data integration toward comprehensive genomic and functional annotation. Several years after the complete genetic sequencing of many species, it is still unclear how to translate genomic information into a functional map of cellular and developmental programs. The Encyclopedia of DNA Elements (ENCODE) (1) and model organism ENCODE (modENCODE) (2) projects use diverse genomic assays to comprehensively annotate the Homo sapiens (human), Drosophila melanogaster (fruit fly), and Caenorhabditis elegans (worm) genomes, through systematic generation and computational integration of functional genomic data sets. Previous genomic studies in flies have made seminal contributions to our understanding of basic biological mechanisms and genome functions, facilitated by genetic, experimental, computational, and manual annotation of the euchromatic and heterochromatic genome (3), small genome size, short life cycle, and a deep knowledge of development, gene function, and chromosome biology. The functions of {approx}40% of the protein and nonprotein-coding genes [FlyBase 5.12 (4)] have been determined from cDNA collections (5, 6), manual curation of gene models (7), gene mutations and comprehensive genome-wide RNA interference screens (8-10), and comparative genomic analyses (11, 12). The Drosophila modENCODE project has generated more than 700 data sets that profile transcripts, histone modifications and physical nucleosome properties, general and specific transcription factors (TFs), and replication programs in cell lines, isolated tissues, and whole organisms across several developmental stages (Fig. 1). Here, we computationally integrate these data sets and report (i) improved and additional genome annotations, including full-length proteincoding genes and peptides as short as 21 amino acids; (ii) noncoding transcripts, including 132 candidate structural RNAs and 1608 nonstructural transcripts; (iii) additional Argonaute (Ago)-associated small RNA genes and pathways, including new microRNAs (miRNAs) encoded within protein-coding exons and endogenous small interfering RNAs (siRNAs) from 3-inch untranslated regions; (iv) chromatin 'states' defined by combinatorial patterns of 18 chromatin marks that are associated with distinct functions and properties; (v) regions of high TF occupancy and replication activity with likely epigenetic regulation; (vi)mixed TF and miRNA regulatory networks with hierarchical structure and enriched feed-forward loops; (vii) coexpression- and co-regulation-based functional annotations for nearly 3000 genes; (viii) stage- and tissue-specific regulators; and (ix) predictive models of gene expression levels and regulator function.« less

The human enamel protein gene amelogenin is expressed from both the X and the Y chromosomes

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

Salido, E.C.; Yen, P.H.; Koprivnikar, K.

1992-02-01

Amelogenins, a family of extracellular matrix proteins of the dental enamel, are transiently but abundantly expressed by ameloblasts during tooth development. In this paper the authors report the characterization of the AMGX and AMGY genes on the short arms of the human X and Y chromosomes which encode the amelogenins. Their studies on the expression of the amelogenin genes in male developing tooth buds showed that both the AMGX and AMGY genes are transcriptionally active and encode potentially functional proteins. They have isolated genomic and cDNA clones form both the AMGX and AMGY loci and have studied the sequence organizationmore » of these two genes. Reverse transcriptase (RT)PCR amplification of the 5[prime] portion of the amelogenin transcripts revealed several alternatively spliced products. This information will be useful for studying the molecular basis of X-linked amelogenesis imperfecta, for understanding the evolution and regulation of gene expression on the mammalian sex chromosomes, and for investigating the role of amelogenin genes during tooth development.« less

A complex of serine protease genes expressed preferentially in cytotoxic T-lymphocytes is closely linked to the T-cell receptor alpha- and delta-chain genes on mouse chromosome 14.

PubMed

Crosby, J L; Bleackley, R C; Nadeau, J H

1990-02-01

A complex of genes encoding serine proteases that are preferentially expressed in cytotoxic T-cells was shown to be closely linked to the T-cell receptor alpha- and delta-chain genes on mouse chromosome 14. A striking difference in recombination frequencies among linkage crosses was reported. Two genes, Np-1 and Tcra, which fail to recombine in crosses involving conventional strains of mice, were shown to recombine readily in interspecific crosses involving Mus spretus. This difference in recombination frequency suggests chromosomal rearrangements that suppress recombination in conventional crosses, recombination hot spots in interspecific crosses, or selection against recombinant haplotypes during development of recombinant inbred strains. Finally, a mutation called disorganization, which is located near the serine protease complex, is of considerable interest because it causes an extraordinarily wide variety of congenital defects. Because of the involvement of serine protease loci in several homeotic mutations in Drosophila, disorganization must be considered a candidate for a mutation in a serine protease-encoding gene.

Whole genome re-sequencing identifies a mutation in an ABC transporter (mdr2) in a Plasmodium chabaudi clone with altered susceptibility to antifolate drugs☆

PubMed Central

Martinelli, Axel; Henriques, Gisela; Cravo, Pedro; Hunt, Paul

2011-01-01

In malaria parasites, mutations in two genes of folate biosynthesis encoding dihydrofolate reductase (dhfr) and dihydropteroate synthase (dhps) modify responses to antifolate therapies which target these enzymes. However, the involvement of other genes which modify the availability of exogenous folate, for example, has been proposed. Here, we used short-read whole-genome re-sequencing to determine the mutations in a clone of the rodent malaria parasite, Plasmodium chabaudi, which has altered susceptibility to both sulphadoxine and pyrimethamine. This clone bears a previously identified S106N mutation in dhfr and no mutation in dhps. Instead, three additional point mutations in genes on chromosomes 2, 13 and 14 were identified. The mutated gene on chromosome 13 (mdr2 K392Q) encodes an ABC transporter. Because Quantitative Trait Locus analysis previously indicated an association of genetic markers on chromosome 13 with responses to individual and combined antifolates, MDR2 is proposed to modulate antifolate responses, possibly mediated by the transport of folate intermediates. PMID:20858498

Imputation and subset-based association analysis across different cancer types identifies multiple independent risk loci in the TERT-CLPTM1L region on chromosome 5p15.33

PubMed Central

Wang, Zhaoming; Zhu, Bin; Zhang, Mingfeng; Parikh, Hemang; Jia, Jinping; Chung, Charles C.; Sampson, Joshua N.; Hoskins, Jason W.; Hutchinson, Amy; Burdette, Laurie; Ibrahim, Abdisamad; Hautman, Christopher; Raj, Preethi S.; Abnet, Christian C.; Adjei, Andrew A.; Ahlbom, Anders; Albanes, Demetrius; Allen, Naomi E.; Ambrosone, Christine B.; Aldrich, Melinda; Amiano, Pilar; Amos, Christopher; Andersson, Ulrika; Andriole, Gerald; Andrulis, Irene L.; Arici, Cecilia; Arslan, Alan A.; Austin, Melissa A.; Baris, Dalsu; Barkauskas, Donald A.; Bassig, Bryan A.; Beane Freeman, Laura E.; Berg, Christine D.; Berndt, Sonja I.; Bertazzi, Pier Alberto; Biritwum, Richard B.; Black, Amanda; Blot, William; Boeing, Heiner; Boffetta, Paolo; Bolton, Kelly; Boutron-Ruault, Marie-Christine; Bracci, Paige M.; Brennan, Paul; Brinton, Louise A.; Brotzman, Michelle; Bueno-de-Mesquita, H. Bas; Buring, Julie E.; Butler, Mary Ann; Cai, Qiuyin; Cancel-Tassin, Geraldine; Canzian, Federico; Cao, Guangwen; Caporaso, Neil E.; Carrato, Alfredo; Carreon, Tania; Carta, Angela; Chang, Gee-Chen; Chang, I-Shou; Chang-Claude, Jenny; Che, Xu; Chen, Chien-Jen; Chen, Chih-Yi; Chen, Chung-Hsing; Chen, Constance; Chen, Kuan-Yu; Chen, Yuh-Min; Chokkalingam, Anand P.; Chu, Lisa W.; Clavel-Chapelon, Francoise; Colditz, Graham A.; Colt, Joanne S.; Conti, David; Cook, Michael B.; Cortessis, Victoria K.; Crawford, E. David; Cussenot, Olivier; Davis, Faith G.; De Vivo, Immaculata; Deng, Xiang; Ding, Ti; Dinney, Colin P.; Di Stefano, Anna Luisa; Diver, W. Ryan; Duell, Eric J.; Elena, Joanne W.; Fan, Jin-Hu; Feigelson, Heather Spencer; Feychting, Maria; Figueroa, Jonine D.; Flanagan, Adrienne M.; Fraumeni, Joseph F.; Freedman, Neal D.; Fridley, Brooke L.; Fuchs, Charles S.; Gago-Dominguez, Manuela; Gallinger, Steven; Gao, Yu-Tang; Gapstur, Susan M.; Garcia-Closas, Montserrat; Garcia-Closas, Reina; Gastier-Foster, Julie M.; Gaziano, J. Michael; Gerhard, Daniela S.; Giffen, Carol A.; Giles, Graham G.; Gillanders, Elizabeth M.; Giovannucci, Edward L.; Goggins, Michael; Gokgoz, Nalan; Goldstein, Alisa M.; Gonzalez, Carlos; Gorlick, Richard; Greene, Mark H.; Gross, Myron; Grossman, H. Barton; Grubb, Robert; Gu, Jian; Guan, Peng; Haiman, Christopher A.; Hallmans, Goran; Hankinson, Susan E.; Harris, Curtis C.; Hartge, Patricia; Hattinger, Claudia; Hayes, Richard B.; He, Qincheng; Helman, Lee; Henderson, Brian E.; Henriksson, Roger; Hoffman-Bolton, Judith; Hohensee, Chancellor; Holly, Elizabeth A.; Hong, Yun-Chul; Hoover, Robert N.; Hosgood, H. Dean; Hsiao, Chin-Fu; Hsing, Ann W.; Hsiung, Chao Agnes; Hu, Nan; Hu, Wei; Hu, Zhibin; Huang, Ming-Shyan; Hunter, David J.; Inskip, Peter D.; Ito, Hidemi; Jacobs, Eric J.; Jacobs, Kevin B.; Jenab, Mazda; Ji, Bu-Tian; Johansen, Christoffer; Johansson, Mattias; Johnson, Alison; Kaaks, Rudolf; Kamat, Ashish M.; Kamineni, Aruna; Karagas, Margaret; Khanna, Chand; Khaw, Kay-Tee; Kim, Christopher; Kim, In-Sam; Kim, Jin Hee; Kim, Yeul Hong; Kim, Young-Chul; Kim, Young Tae; Kang, Chang Hyun; Jung, Yoo Jin; Kitahara, Cari M.; Klein, Alison P.; Klein, Robert; Kogevinas, Manolis; Koh, Woon-Puay; Kohno, Takashi; Kolonel, Laurence N.; Kooperberg, Charles; Kratz, Christian P.; Krogh, Vittorio; Kunitoh, Hideo; Kurtz, Robert C.; Kurucu, Nilgun; Lan, Qing; Lathrop, Mark; Lau, Ching C.; Lecanda, Fernando; Lee, Kyoung-Mu; Lee, Maxwell P.; Le Marchand, Loic; Lerner, Seth P.; Li, Donghui; Liao, Linda M.; Lim, Wei-Yen; Lin, Dongxin; Lin, Jie; Lindstrom, Sara; Linet, Martha S.; Lissowska, Jolanta; Liu, Jianjun; Ljungberg, Börje; Lloreta, Josep; Lu, Daru; Ma, Jing; Malats, Nuria; Mannisto, Satu; Marina, Neyssa; Mastrangelo, Giuseppe; Matsuo, Keitaro; McGlynn, Katherine A.; McKean-Cowdin, Roberta; McNeill, Lorna H.; McWilliams, Robert R.; Melin, Beatrice S.; Meltzer, Paul S.; Mensah, James E.; Miao, Xiaoping; Michaud, Dominique S.; Mondul, Alison M.; Moore, Lee E.; Muir, Kenneth; Niwa, Shelley; Olson, Sara H.; Orr, Nick; Panico, Salvatore; Park, Jae Yong; Patel, Alpa V.; Patino-Garcia, Ana; Pavanello, Sofia; Peeters, Petra H. M.; Peplonska, Beata; Peters, Ulrike; Petersen, Gloria M.; Picci, Piero; Pike, Malcolm C.; Porru, Stefano; Prescott, Jennifer; Pu, Xia; Purdue, Mark P.; Qiao, You-Lin; Rajaraman, Preetha; Riboli, Elio; Risch, Harvey A.; Rodabough, Rebecca J.; Rothman, Nathaniel; Ruder, Avima M.; Ryu, Jeong-Seon; Sanson, Marc; Schned, Alan; Schumacher, Fredrick R.; Schwartz, Ann G.; Schwartz, Kendra L.; Schwenn, Molly; Scotlandi, Katia; Seow, Adeline; Serra, Consol; Serra, Massimo; Sesso, Howard D.; Severi, Gianluca; Shen, Hongbing; Shen, Min; Shete, Sanjay; Shiraishi, Kouya; Shu, Xiao-Ou; Siddiq, Afshan; Sierrasesumaga, Luis; Sierri, Sabina; Loon Sihoe, Alan Dart; Silverman, Debra T.; Simon, Matthias; Southey, Melissa C.; Spector, Logan; Spitz, Margaret; Stampfer, Meir; Stattin, Par; Stern, Mariana C.; Stevens, Victoria L.; Stolzenberg-Solomon, Rachael Z.; Stram, Daniel O.; Strom, Sara S.; Su, Wu-Chou; Sund, Malin; Sung, Sook Whan; Swerdlow, Anthony; Tan, Wen; Tanaka, Hideo; Tang, Wei; Tang, Ze-Zhang; Tardon, Adonina; Tay, Evelyn; Taylor, Philip R.; Tettey, Yao; Thomas, David M.; Tirabosco, Roberto; Tjonneland, Anne; Tobias, Geoffrey S.; Toro, Jorge R.; Travis, Ruth C.; Trichopoulos, Dimitrios; Troisi, Rebecca; Truelove, Ann; Tsai, Ying-Huang; Tucker, Margaret A.; Tumino, Rosario; Van Den Berg, David; Van Den Eeden, Stephen K.; Vermeulen, Roel; Vineis, Paolo; Visvanathan, Kala; Vogel, Ulla; Wang, Chaoyu; Wang, Chengfeng; Wang, Junwen; Wang, Sophia S.; Weiderpass, Elisabete; Weinstein, Stephanie J.; Wentzensen, Nicolas; Wheeler, William; White, Emily; Wiencke, John K.; Wolk, Alicja; Wolpin, Brian M.; Wong, Maria Pik; Wrensch, Margaret; Wu, Chen; Wu, Tangchun; Wu, Xifeng; Wu, Yi-Long; Wunder, Jay S.; Xiang, Yong-Bing; Xu, Jun; Yang, Hannah P.; Yang, Pan-Chyr; Yatabe, Yasushi; Ye, Yuanqing; Yeboah, Edward D.; Yin, Zhihua; Ying, Chen; Yu, Chong-Jen; Yu, Kai; Yuan, Jian-Min; Zanetti, Krista A.; Zeleniuch-Jacquotte, Anne; Zheng, Wei; Zhou, Baosen; Mirabello, Lisa; Savage, Sharon A.; Kraft, Peter; Chanock, Stephen J.; Yeager, Meredith; Landi, Maria Terese; Shi, Jianxin; Chatterjee, Nilanjan; Amundadottir, Laufey T.

2014-01-01

Genome-wide association studies (GWAS) have mapped risk alleles for at least 10 distinct cancers to a small region of 63 000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (association analysis based on subsets) across six distinct cancers in 34 248 cases and 45 036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single-nucleotide polymorphisms: five in the TERT gene (Region 1: rs7726159, P = 2.10 × 10−39; Region 3: rs2853677, P = 3.30 × 10−36 and PConditional = 2.36 × 10−8; Region 4: rs2736098, P = 3.87 × 10−12 and PConditional = 5.19 × 10−6, Region 5: rs13172201, P = 0.041 and PConditional = 2.04 × 10−6; and Region 6: rs10069690, P = 7.49 × 10−15 and PConditional = 5.35 × 10−7) and one in the neighboring CLPTM1L gene (Region 2: rs451360; P = 1.90 × 10−18 and PConditional = 7.06 × 10−16). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele-specific effects on DNA methylation were seen for a subset of risk loci, indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci. PMID:25027329

A novel, broad-range, CTXΦ-derived stable integrative expression vector for functional studies.

PubMed

Das, Bhabatosh; Kumari, Reena; Pant, Archana; Sen Gupta, Sourav; Saxena, Shruti; Mehta, Ojasvi; Nair, Gopinath Balakrish

2014-12-01

CTXΦ, a filamentous vibriophage encoding cholera toxin, uses a unique strategy for its lysogeny. The single-stranded phage genome forms intramolecular base-pairing interactions between two inversely oriented XerC and XerD binding sites (XBS) and generates a functional phage attachment site, attP(+), for integration. The attP(+) structure is recognized by the host-encoded tyrosine recombinases XerC and XerD (XerCD), which enables irreversible integration of CTXΦ into the chromosome dimer resolution site (dif) of Vibrio cholerae. The dif site and the XerCD recombinases are widely conserved in bacteria. We took advantage of these conserved attributes to develop a broad-host-range integrative expression vector that could irreversibly integrate into the host chromosome using XerCD recombinases without altering the function of any known open reading frame (ORF). In this study, we engineered two different arabinose-inducible expression vectors, pBD62 and pBD66, using XBS of CTXΦ. pBD62 replicates conditionally and integrates efficiently into the dif of the bacterial chromosome by site-specific recombination using host-encoded XerCD recombinases. The expression level of the gene of interest could be controlled through the PBAD promoter by modulating the functions of the vector-encoded transcriptional factor AraC. We validated the irreversible integration of pBD62 into a wide range of pathogenic and nonpathogenic bacteria, such as V. cholerae, Vibrio fluvialis, Vibrio parahaemolyticus, Escherichia coli, Salmonella enterica, and Klebsiella pneumoniae. Gene expression from the PBAD promoter of integrated vectors was confirmed in V. cholerae using the well-studied reporter genes mCherry, eGFP, and lacZ. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Identification of a feather β-keratin gene exclusively expressed in pennaceous barbule cells of contour feathers in chicken.

PubMed

Kowata, Kinue; Nakaoka, Minori; Nishio, Kaori; Fukao, Ayaka; Satoh, Akira; Ogoshi, Maho; Takahashi, Sumio; Tsudzuki, Masaoki; Takeuchi, Sakae

2014-05-25

Feathers are elaborate skin appendages shared by birds and theropod dinosaurs that have hierarchical branching of the rachis, barbs, and barbules. Feather filaments consist of β-keratins encoded by multiple genes, most of which are located in tandem arrays on chromosomes 2, 25, and 27 in chicken. The expansion of the genes is thought to have contributed to feather evolution; however, it is unclear how the individual genes are involved in feather formation. The aim of the present study was to identify feather keratin genes involved in the formation of barbules. Using a combination of microarray analysis, reverse-transcription polymerase chain reaction, and in situ hybridization, we found an uncharacterized keratin gene on chromosome 7 that was expressed specifically in barbule cells in regenerating chicken feathers. We have named the gene barbule specific keratin 1 (BlSK1). The BlSK1 gene structure was similar to the gene structure of previously characterized feather keratin genes, and consisted of a non-coding leader exon, an intron, and an exon with an open reading frame (ORF). The ORF was predicted to encode a 98 aa long protein, which shared 59% identity with feather keratin B. Orthologs of BlSK1 were found in the genomes of other avian species, including turkey, duck, zebra finch, and flycatcher, in regions that shared synteny with chromosome 7 of chicken. Interestingly, BlSK1 was expressed in feather follicles that generated pennaceous barbules but not in follicles that generated plumulaceous barbules. These results suggested that the composition of feather keratins probably varies depending on the structure of the feather filaments and, that individual feather keratin genes may be involved in building different portions and/or types of feathers in chicken. Copyright © 2014 Elsevier B.V. All rights reserved.

Genes encoded within 8q24 on the amplicon of a large extrachromosomal element are selectively repressed during the terminal differentiation of HL-60 cells.

PubMed

Hirano, Tetsuo; Ike, Fumio; Murata, Takehide; Obata, Yuichi; Utiyama, Hiroyasu; Yokoyama, Kazunari K

2008-04-02

Human acute myeloblastic leukemia HL-60 cells become resistant to differentiation during long-term cultivation. After 150 passages, double minute chromosomes (dmins) found in early-passaged cells are replaced by large extrachromosomal elements (LEEs). In a DNA library derived from a purified fraction of LEEs, 12.6% (23/183) of clones were assigned to 8q24 and 9.2% (17/183) were assigned to 14q11 in the human genome. Fluorescence in situ hybridization (FISH) revealed a small aberrant chromosome, which had not been found in early-passaged cells, in addition to the purified LEEs. We determined that each LEE consisted of six discontinuous segments in a region that extended for 4.4Mb over the 8q24 locus. Five genes, namely, Myc (a proto-oncogene), NSMCE2 (for a SUMO ligase), CCDC26 (for a retinoic acid-dependent modulator of myeloid differentiation), TRIB1 (for a regulator of MAPK kinase) and LOC389637 (for a protein of unknown function), were encoded by the amplicon. Breaks in the chromosomal DNA within the amplicon were found in the NSMCE2 and CCDC26 genes. The discontinuous structure of the amplicon unit of the LEEs was identical with that of dmins in HL-60 early-passaged cells. The difference between them seemed, predominantly, to be the number (10-15 copies per LEE versus 2 or 3 copies per dmin) of constituent units. Expression of the Myc, NSMCE2, CCDC26 and LOC389637 and TRIB1 genes was constitutive in all lines of HL-60 cells and that of the first four genes was repressed during the terminal differentiation of early-passaged HL-60 cells. We also detected abnormal transcripts of CCDC26. Our results suggest that these genes were selected during the development of amplicons. They might be amplified and, sometimes, truncated to contribute to the maintenance of HL-60 cells in an undifferentiated state.

Pestoides F, an atypical Yersinia pestis strain from the former Soviet Union.

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

Garcia, Emilio; Worsham, Patricia; Bearden, S.

2007-01-01

Unlike the classical Yersinia pestis strains, members of an atypical group of Y. pestis from Central Asia, denominated Y. pestis subspecies caucasica (also known as one of several pestoides types), are distinguished by a number of characteristics including their ability to ferment rhamnose and melibiose, their lack of the small plasmid encoding the plasminogen activator (pla) and pesticin, and their exceptionally large variants of the virulence plasmid pMT (encoding murine toxin and capsular antigen). We have obtained the entire genome sequence of Y. pestis Pestoides F, an isolate from the former Soviet Union that has enabled us to carryout amore » comprehensive genome-wide comparison of this organism's genomic content against the six published sequences of Y. pestis and their Y. pseudotuberculosis ancestor. Based on classical glycerol fermentation (+ve) and nitrate reduction (+ve) Y. pestis Pestoides F is an isolate that belongs to the biovar antiqua. This strain is unusual in other characteristics such as the fact that it carries a non-consensus V antigen (lcrV) sequence, and that unlike other Pla(-) strains, Pestoides F retains virulence by the parenteral and aerosol routes. The chromosome of Pestoides F is 4,517,345 bp in size comprising some 3,936 predicted coding sequences, while its pCD and pMT plasmids are 71,507 bp and 137,010 bp in size respectively. Comparison of chromosome-associated genes in Pestoides F with those in the other sequenced Y. pestis strains reveals differences ranging from strain-specific rearrangements, insertions, deletions, single nucleotide polymorphisms, and a unique distribution of insertion sequences. There is a single approximately 7 kb unique region in the chromosome not found in any of the completed Y. pestis strains sequenced to date, but which is present in the Y. pseudotuberculosis ancestor. Taken together, these findings are consistent with Pestoides F being derived from the most ancient lineage of Y. pestis yet sequenced.« less

Pestoides F, and Atypical Yersinia pestis Strain from the Former Soviet Union

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

Garcia, E; Worsham, P; Bearden, S

2007-01-05

Unlike the classical Yersinia pestis strains, members of an atypical group of Y. pestis from Central Asia, denominated Y. pestis subspecies caucasica (also known as one of several pestoides types), are distinguished by a number of characteristics including their ability to ferment rhamnose and melibiose, their lacking the small plasmid encoding the plasminogen activator (pla) and pesticin, and their exceptionally large variants of the virulence plasmid pMT (encoding murine toxin and capsular antigen). We have obtained the entire genome sequence of Y. pestis Pestoides F, an isolate from the former Soviet Union that has enabled us to carryout a comprehensivemore » genome-wide comparison of this organism's genomic content against the six published sequences of Y. pestis and their Y. pseudotuberculosis ancestor. Based on classical glycerol fermentation (+ve) and nitrate reduction (+ve) Y. pestis Pestoides F is an isolate that belongs to the biovar antiqua. This strain is unusual in other characteristics such as the fact that it carries a non-consensus V antigen (lcrV) sequence, and that unlike other Pla{sup -} strains, Pestoides F retains virulence by the parenteral and aerosol routes. The chromosome of Pestoides F is 4,517,345 bp in size comprising some 3,936 predicted coding sequences, while its pCD and pMT plasmids are 71,507 bp and 137,010 bp in size respectively. Comparison of chromosome-associated genes in Pestoides F with those in the other sequenced Y. pestis strains, reveals a series of differences ranging from strain-specific rearrangements, insertions, deletions, single nucleotide polymorphisms, and a unique distribution of insertion sequences. There is a single {approx}7 kb unique region in the chromosome not found in any of the completed Y. pestis strains sequenced to date, but which is present in the Y. pseudotuberculosis ancestor. Taken together, these findings are consistent with Pestoides F being derived from the most ancient lineage of Y. pestis yet sequenced.« less

Paternally inherited microdeletion at 15q11.2 confirms a significant role for the SNORD116 C/D box snoRNA cluster in Prader-Willi syndrome.

PubMed

Duker, Angela L; Ballif, Blake C; Bawle, Erawati V; Person, Richard E; Mahadevan, Sangeetha; Alliman, Sarah; Thompson, Regina; Traylor, Ryan; Bejjani, Bassem A; Shaffer, Lisa G; Rosenfeld, Jill A; Lamb, Allen N; Sahoo, Trilochan

2010-11-01

Prader-Willi syndrome (PWS) is a neurobehavioral disorder manifested by infantile hypotonia and feeding difficulties in infancy, followed by morbid obesity secondary to hyperphagia. It is caused by deficiency of paternally expressed transcript(s) within the human chromosome region 15q11.2. PWS patients harboring balanced chromosomal translocations with breakpoints within small nuclear ribonucleoprotein polypeptide N (SNRPN) have provided indirect evidence for a role for the imprinted C/D box containing small nucleolar RNA (snoRNA) genes encoded downstream of SNRPN. In addition, recently published data provide strong evidence in support of a role for the snoRNA SNORD116 cluster (HBII-85) in PWS etiology. In this study, we performed detailed phenotypic, cytogenetic, and molecular analyses including chromosome analysis, array comparative genomic hybridization (array CGH), expression studies, and single-nucleotide polymorphism (SNP) genotyping for parent-of-origin determination of the 15q11.2 microdeletion on an 11-year-old child expressing the major components of the PWS phenotype. This child had an ∼236.29 kb microdeletion at 15q11.2 within the larger Prader-Willi/Angelman syndrome critical region that included the SNORD116 cluster of snoRNAs. Analysis of SNP genotypes in proband and mother provided evidence in support of the deletion being on the paternal chromosome 15. This child also met most of the major PWS diagnostic criteria including infantile hypotonia, early-onset morbid obesity, and hypogonadism. Identification and characterization of this case provide unequivocal evidence for a critical role for the SNORD116 snoRNA molecules in PWS pathogenesis. Array CGH testing for genomic copy-number changes in cases with complex phenotypes is proving to be invaluable in detecting novel alterations and enabling better genotype-phenotype correlations.

Organization, regulatory sequences, and alternatively spliced transcripts of the mucosal addressin cell adhesion molecule-1 (MAdCAM-1) gene

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

Sampaio, S.O.; Mei, C.; Butcher, E.C.

The mucosal addressin cell adhesion molecule-1 (MAdCAM-1) is expressed selectively at venular sites of lymphocyte extravasation into mucosal lymphoid tissues and lamina propria, where it directs local lymphocyte trafficking. MAdCAM-1 is a multifunctional type I transmembrane adhesion molecule comprising two distal Ig domains involved in {alpha}4{beta}7 integrin binding, a mucin-like region able to display L-selectin-binding carbohydrates, and a membrane-proximal Ig domain homologous to IgA. We show in this work that the MAdCAM-1 gene is located on chromosome 10 and contains five exons. The signal peptide and each one of the three Ig domains are encoded by a distinct exon, whereasmore » the transmembrane, cytoplasmic tail, and 3{prime}-untranslated region of MAdCAM-1 are combined on a single exon. The mucin-like region and the third Ig domain are encoded together on exon 4. An alternatively spliced MAdCAM-1 mRNA is identified that lacks the mucin/IgA-homologous exon 4-encoded sequences. This short variant of MAdCAM-1 may be specialized to support {alpha}4{beta}7-dependent adhesion strengthening, independent of carbohydrate-presenting function. Sequences 5{prime} of the transcription start site include tandem nuclear factor-KB sites; AP-1, AP-2, and signal peptide-1 binding sites; and an estrogen response element. Our findings reinforce the correspondence between the multidomain structure and versatile functions of this vascular addressin, and suggest an additional level of regulation of carbohydrate-presenting capability, and thus of its importance in lectin-mediated vs. {alpha}4{beta}7-dependent adhesive events in lymphocyte trafficking. 46 refs., 6 figs., 1 tab.« less

Mapping and Sequencing of the Canine NRAMP1 Gene and Identification of Mutations in Leishmaniasis-Susceptible Dogs

PubMed Central

Altet, Laura; Francino, Olga; Solano-Gallego, Laia; Renier, Corinne; Sánchez, Armand

2002-01-01

The NRAMP1 gene (Slc11a1) encodes an ion transporter protein involved in the control of intraphagosomal replication of parasites and in macrophage activation. It has been described in mice as the determinant of natural resistance or susceptibility to infection with antigenically unrelated pathogens, including Leishmania. Our aims were to sequence and map the canine Slc11a1 gene and to identify mutations that may be associated with resistance or susceptibility to Leishmania infection. The canine Slc11a1 gene has been mapped to dog chromosome CFA37 and covers 9 kb, including a 700-bp promoter region, 15 exons, and a polymorphic microsatellite in intron 1. It encodes a 547-amino-acid protein that has over 87% identity with the Slc11a1 proteins of different mammalian species. A case-control study with 33 resistant and 84 susceptible dogs showed an association between allele 145 of the microsatellite and susceptible dogs. Sequence variant analysis was performed by direct sequencing of the cDNA and the promoter region of four unrelated beagles experimentally infected with Leishmania infantum to search for possible functional mutations. Two of the dogs were classified as susceptible and the other two were classified as resistant based on their immune responses. Two important mutations were found in susceptible dogs: a G-rich region in the promoter that was common to both animals and a complete deletion of exon 11, which encodes the consensus transport motif of the protein, in the unique susceptible dog that needed an additional and prolonged treatment to avoid continuous relapses. A study with a larger dog population would be required to prove the association of these sequence variants with disease susceptibility. PMID:12010961

Genome-wide QTL and bulked transcriptomic analysis reveals new candidate genes for the control of tuber carotenoid content in potato (Solanum tuberosum L.).

PubMed

Campbell, Raymond; Pont, Simon D A; Morris, Jenny A; McKenzie, Gaynor; Sharma, Sanjeev Kumar; Hedley, Pete E; Ramsay, Gavin; Bryan, Glenn J; Taylor, Mark A

2014-09-01

Genome-wide QTL analysis of potato tuber carotenoid content was investigated in populations of Solanum tuberosum Group Phureja that segregate for flesh colour, revealing a novel major QTL on chromosome 9. The carotenoid content of edible plant storage organs is a key nutritional and quality trait. Although the structural genes that encode the biosynthetic enzymes are well characterised, much less is known about the factors that determine overall storage organ content. In this study, genome-wide QTL mapping, in concert with an efficient 'genetical genomics' analysis using bulked samples, has been employed to investigate the genetic architecture of potato tuber carotenoid content. Two diploid populations of Solanum tuberosum Group Phureja were genotyped (AFLP, SSR and DArT markers) and analysed for their tuber carotenoid content over two growing seasons. Common to both populations were QTL that explained relatively small proportions of the variation in constituent carotenoids and a major QTL on chromosome 3 explaining up to 71 % of the variation in carotenoid content. In one of the populations (01H15), a second major carotenoid QTL was identified on chromosome 9, explaining up to 20 % of the phenotypic variation. Whereas the major chromosome 3 QTL was likely to be due to an allele of a gene encoding β-carotene hydroxylase, no known carotenoid biosynthetic genes are located in the vicinity of the chromosome 9 QTL. A unique expression profiling strategy using phenotypically distinct bulks comprised individuals with similar carotenoid content provided further support for the QTL mapping to chromosome 9. This study shows the potential of using the potato genome sequence to link genetic maps to data arising from eQTL approaches to enhance the discovery of candidate genes underlying QTLs.

[Neonatal diabetes mellitus].

PubMed

Gurgel, Lucimary C; Moisés, Regina S

2008-03-01

Neonatal diabetes is a rare condition characterized by hyperglycemia, requiring insulin treatment, diagnosed within the first months of life. The disorder may be either transient, resolving in infancy or early childhood with possible relapse later, or permanent in which case lifelong treatment is necessary. Both conditions are genetically heterogeneous; however, the majority of the cases of transient neonatal diabetes are due to abnormalities of an imprinted region of chromosome 6q24. For permanent neonatal diabetes, the most common causes are heterozygous activating mutations of KCNJ11, the gene encoding the Kir6.2 sub-unit of the ATP-sensitive potassium channel. In this article we discuss the clinical features of neonatal diabetes, the underlying genetic defects and the therapeutic implications.

Lignin peroxidase gene family of Phanerochaete chrysosporium : complex regulation by carbon and nitrogen limitation and identification of a second dimorphic chromosome

Treesearch

Philip Stewart; Philip Kersten; Amber J. Vanden Wymelenberg; Jill A. Gaskell; Daniel Cullen

1992-01-01

Lignin peroxidases (LiP) of Phanerochaete chrysosporium are encoded by a family of six closely related genes. Five LiP genes have been localized to the same dimorphic chromosome. In this investigation, relative transcript levels of the LiP genes were determined. Transcripts of the LiPA, LiPB, and 0282 genes were at similar levels in both carbon-and nitrogen-limited...

Assignment of electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) to human chromosome 4q33 by fluorescence in situ hybridization and somatic cell hybridization.

PubMed

Spector, E B; Seltzer, W K; Goodman, S I

1999-08-01

Electron transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO) is a nuclear-encoded protein located in the inner mitochondrial membrane. Inherited defects of ETF-QO cause glutaric acidemia type II. We here describe the localization of the ETF-QO gene to human chromosome 4q33 by somatic cell hybridization and fluorescence in situ hybridization. Copyright 1999 Academic Press.

A genome-wide association study for somatic cell score using the Illumina high-density bovine beadchip identifies several novel QTL potentially related to mastitis susceptibility

PubMed Central

Meredith, Brian K.; Berry, Donagh P.; Kearney, Francis; Finlay, Emma K.; Fahey, Alan G.; Bradley, Daniel G.; Lynn, David J.

2013-01-01

Mastitis is an inflammation-driven disease of the bovine mammary gland that occurs in response to physical damage or infection and is one of the most costly production-related diseases in the dairy industry worldwide. We performed a genome-wide association study (GWAS) to identify genetic loci associated with somatic cell score (SCS), an indicator trait of mammary gland inflammation. A total of 702 Holstein-Friesian bulls were genotyped for 777,962 single nucleotide polymorphisms (SNPs) and associated with SCS phenotypes. The SCS phenotypes were expressed as daughter yield deviations (DYD) based on a large number of progeny performance records. A total of 138 SNPs on 15 different chromosomes reached genome-wide significance (corrected p-value ≤ 0.05) for association with SCS (after correction for multiple testing). We defined 28 distinct QTL regions and a number of candidate genes located in these QTL regions were identified. The most significant association (p-value = 1.70 × 10−7) was observed on chromosome 6. This QTL had no known genes annotated within it, however, the Ensembl Genome Browser predicted the presence of a small non-coding RNA (a Y RNA gene) in this genomic region. This Y RNA gene was 99% identical to human RNY4. Y RNAs are a rare type of non-coding RNA that were originally discovered due to their association with the autoimmune disease, systemic lupus erythematosus. Examining small-RNA sequencing (RNAseq) data being generated by us in multiple different mastitis-pathogen challenged cell-types has revealed that this Y RNA is expressed (but not differentially expressed) in these cells. Other QTL regions identified in this study also encoded strong candidate genes for mastitis susceptibility. A QTL region on chromosome 13, for example, was found to contain a cluster of β-defensin genes, a gene family with known roles in innate immunity. Due to the increased SNP density, this study also refined the boundaries for several known QTL for SCS and mastitis. PMID:24223582

Detection of maltose fermentation genes in the baking yeast strains of Saccharomyces cerevisiae.

PubMed

Oda, Y; Tonomura, K

1996-10-01

The presence of any one of the five unlinked MAL loci (MAL1, MAL2, MAL3, MAL4 and MAL6) confers the ability to ferment maltose on the yeast Saccharomyces cerevisiae. Each locus is composed of three genes encoding maltose permease, alpha-glucosidase and MAL activator. Chromosomal DNA of seven representative baking strains has been separated by pulse-field gel electrophoresis and probed with three genes in MAL6 locus. The DNA bands to which all of the three MAL-derived probes simultaneously hybridized were chromosome VII carrying MAL1 in all of the strains tested, chromosome XI carrying MAL4 in six strains, chromosome III carrying MAL2 in three strains and chromosomes II and VIII carrying MAL3 and MAL6, respectively, in the one strain. The number of MAL loci in baking strains was comparable to those of brewing strains.

Telomere structure and maintenance gene variants and risk of five cancer types.

PubMed

Karami, Sara; Han, Younghun; Pande, Mala; Cheng, Iona; Rudd, James; Pierce, Brandon L; Nutter, Ellen L; Schumacher, Fredrick R; Kote-Jarai, Zsofia; Lindstrom, Sara; Witte, John S; Fang, Shenying; Han, Jiali; Kraft, Peter; Hunter, David J; Song, Fengju; Hung, Rayjean J; McKay, James; Gruber, Stephen B; Chanock, Stephen J; Risch, Angela; Shen, Hongbing; Haiman, Christopher A; Boardman, Lisa; Ulrich, Cornelia M; Casey, Graham; Peters, Ulrike; Amin Al Olama, Ali; Berchuck, Andrew; Berndt, Sonja I; Bezieau, Stephane; Brennan, Paul; Brenner, Hermann; Brinton, Louise; Caporaso, Neil; Chan, Andrew T; Chang-Claude, Jenny; Christiani, David C; Cunningham, Julie M; Easton, Douglas; Eeles, Rosalind A; Eisen, Timothy; Gala, Manish; Gallinger, Steven J; Gayther, Simon A; Goode, Ellen L; Grönberg, Henrik; Henderson, Brian E; Houlston, Richard; Joshi, Amit D; Küry, Sébastien; Landi, Mari T; Le Marchand, Loic; Muir, Kenneth; Newcomb, Polly A; Permuth-Wey, Jenny; Pharoah, Paul; Phelan, Catherine; Potter, John D; Ramus, Susan J; Risch, Harvey; Schildkraut, Joellen; Slattery, Martha L; Song, Honglin; Wentzensen, Nicolas; White, Emily; Wiklund, Fredrik; Zanke, Brent W; Sellers, Thomas A; Zheng, Wei; Chatterjee, Nilanjan; Amos, Christopher I; Doherty, Jennifer A

2016-12-15

Telomeres cap chromosome ends, protecting them from degradation, double-strand breaks, and end-to-end fusions. Telomeres are maintained by telomerase, a reverse transcriptase encoded by TERT, and an RNA template encoded by TERC. Loci in the TERT and adjoining CLPTM1L region are associated with risk of multiple cancers. We therefore investigated associations between variants in 22 telomere structure and maintenance gene regions and colorectal, breast, prostate, ovarian, and lung cancer risk. We performed subset-based meta-analyses of 204,993 directly-measured and imputed SNPs among 61,851 cancer cases and 74,457 controls of European descent. Independent associations for SNP minor alleles were identified using sequential conditional analysis (with gene-level p value cutoffs ≤3.08 × 10 -5 ). Of the thirteen independent SNPs observed to be associated with cancer risk, novel findings were observed for seven loci. Across the DCLRE1B region, rs974494 and rs12144215 were inversely associated with prostate and lung cancers, and colorectal, breast, and prostate cancers, respectively. Across the TERC region, rs75316749 was positively associated with colorectal, breast, ovarian, and lung cancers. Across the DCLRE1B region, rs974404 and rs12144215 were inversely associated with prostate and lung cancers, and colorectal, breast, and prostate cancers, respectively. Near POT1, rs116895242 was inversely associated with colorectal, ovarian, and lung cancers, and RTEL1 rs34978822 was inversely associated with prostate and lung cancers. The complex association patterns in telomere-related genes across cancer types may provide insight into mechanisms through which telomere dysfunction in different tissues influences cancer risk. © 2016 UICC.

Genetic markers associated with dihydroartemisinin–piperaquine failure in Plasmodium falciparum malaria in Cambodia: a genotype-phenotype association study

PubMed Central

Amato, Roberto; Lim, Pharath; Miotto, Olivo; Amaratunga, Chanaki; Dek, Dalin; Pearson, Richard D.; Almagro-Garcia, Jacob; Neal, Aaron T.; Sreng, Sokunthea; Suon, Seila; Drury, Eleanor; Jyothi, Dushyanth; Stalker, Jim; Kwiatkowski, Dominic P.; Fairhurst, Rick M.

2017-01-01

Summary Background As the prevalence of artemisinin-resistant Plasmodium falciparum malaria increases in the Greater Mekong Subregion (GMS), emerging resistance to partner drugs in artemisinin combination therapies (ACTs) seriously threatens global efforts to treat and eliminate this disease. Molecular markers for ACT failure are urgently needed to monitor the spread of partner drug resistance, and to recommend alternative treatments in Southeast Asia and beyond. Methods We performed a genome-wide association study (GWAS) of 297 P. falciparum isolates from Cambodia to investigate the relationship of 11,630 exonic single-nucleotide polymorphisms (SNPs) and 43 copy number variations (CNVs) with in-vitro piperaquine 50% inhibitory concentrations (IC50s), and tested whether these genetic variants are markers of dihydroartemisinin-piperaquine failures. We then performed a survival analysis of 133 patients to determine whether candidate molecular markers predicted parasite recrudescence following dihydroartemisinin-piperaquine treatment. Findings Piperaquine IC50s increased significantly from 2011 to 2013 in 3 Cambodian provinces. Genome-wide analysis of SNPs identified a chromosome 13 region that associates with elevated piperaquine IC50s. A nonsynonymous SNP (encoding a Glu415Gly substitution) in this region, within a gene encoding an exonuclease, associates with parasite recrudescence following dihydroartemisinin-piperaquine treatment. Genome-wide analysis of CNVs revealed that a single copy of the mdr1 gene on chromosome 5 and a novel amplification of the plasmepsin II and plasmepsin III genes on chromosome 14 also associate with elevated piperaquine IC50s. After adjusting for covariates, both exo-E415G and plasmepsin II-III markers significantly associate with decreased treatment efficacy (0.38 and 0.41 survival rates, respectively). Interpretation The exo-E415G SNP and plasmepsin II-III amplification are markers of piperaquine resistance and dihydroartemisinin-piperaquine failures in Cambodia, and can help monitor the spread of these phenotypes into GMS countries, and elucidate the mechanism of piperaquine resistance. Since plasmepsins are involved in the parasite’s haemoglobin-to-haemozoin conversion pathway, targeted by related antimalarials, plasmepsin II-III amplification likely mediates piperaquine resistance. Funding Intramural Research Program of the US National Institute of Allergy and Infectious Diseases, National Institutes of Health; Wellcome Trust; Bill and Melinda Gates Foundation; Medical Research Council; and UK Department for International Development. PMID:27818095

Loss of centromeric histone H3 (CENH3) from centromeres precedes uniparental chromosome elimination in interspecific barley hybrids.

PubMed

Sanei, Maryam; Pickering, Richard; Kumke, Katrin; Nasuda, Shuhei; Houben, Andreas

2011-08-16

Uniparental chromosome elimination occurs in several interspecific hybrids of plants. We studied the mechanism underlying selective elimination of the paternal chromosomes during the early development of Hordeum vulgare × Hordeum bulbosum embryos. The following conclusions regarding the role of the centromere-specific histone H3 variant (CENH3) in the process of chromosome elimination were drawn: (i) centromere inactivity of H. bulbosum chromosomes triggers the mitosis-dependent process of uniparental chromosome elimination in unstable H. vulgare × H. bulbosum hybrids; (ii) centromeric loss of CENH3 protein rather than uniparental silencing of CENH3 genes causes centromere inactivity; (iii) in stable species combinations, cross-species incorporation of CENH3 occurs despite centromere-sequence differences, and not all CENH3 variants get incorporated into centromeres if multiple CENH3s are present in species combinations; and (iv) diploid barley species encode two CENH3 variants, the proteins of which are intermingled within centromeres throughout mitosis and meiosis.

A large inversion in the linear chromosome of Streptomyces griseus caused by replicative transposition of a new Tn3 family transposon.

PubMed

Murata, M; Uchida, T; Yang, Y; Lezhava, A; Kinashi, H

2011-04-01

We have comprehensively analyzed the linear chromosomes of Streptomyces griseus mutants constructed and kept in our laboratory. During this study, macrorestriction analysis of AseI and DraI fragments of mutant 402-2 suggested a large chromosomal inversion. The junctions of chromosomal inversion were cloned and sequenced and compared with the corresponding target sequences in the parent strain 2247. Consequently, a transposon-involved mechanism was revealed. Namely, a transposon originally located at the left target site was replicatively transposed to the right target site in an inverted direction, which generated a second copy and at the same time caused a 2.5-Mb chromosomal inversion. The involved transposon named TnSGR was grouped into a new subfamily of the resolvase-encoding Tn3 family transposons based on its gene organization. At the end, terminal diversity of S. griseus chromosomes is discussed by comparing the sequences of strains 2247 and IFO13350.

Delineation and physical separation of novel translocation breakpoints on chromosome 1p in two genetically closely associated childhood tumors.

PubMed

Steenman, M J; Zijlstra, N; Kruitbosch, D L; Wiesmeijer, C; Larizza, L; Voûte, P A; Westerveld, A; Mannens, M M

2000-01-01

Sporadic childhood tumors associated with Beckwith-Wiedemann syndrome (BWS) all show abnormalities of the same region on chromosome 11. In addition to chromosome 11, other chromosome regions are affected in some of these tumor types. In this study we analyzed the region on chromosome 1p involved in the etiology of BWS-associated tumors, Wilms tumor, rhabdomyosarcoma, and hepatoblastoma. For this purpose we determined the location of two novel translocation breakpoints in this chromosome region in cells from a Wilms tumor and cells from a rhabdomyosarcoma. We constructed a map of the region and found that both breakpoints are separated by at least 875 kb. We identified a PAC clone which crosses the rhabdomyosarcoma breakpoint and found several exons within this clone. We established that this breakpoint is located proximal to the PAX7 gene and, therefore, identified a new region involved in the etiology of rhabdomyosarcomas. Copyright 2000 S. Karger AG, Basel

Fine Structure Genetic and Physical Map of the Gene 3 to 10 Region of the Bacteriophage P22 Chromosome

PubMed Central

Casjens, S.; Eppler, K.; Sampson, L.; Parr, R.; Wyckoff, E.

1991-01-01

The mechanism by which dsDNA is packaged by viruses is not yet understood in any system. Bacteriophage P22 has been a productive system in which to study the molecular genetics of virus particle assembly and DNA packaging. Only five phage encoded proteins, the products of genes 3, 2, 1, 8 and 5, are required for packaging the virus chromosome inside the coat protein shell. We report here the construction of a detailed genetic and physical map of these genes, the neighboring gene 4 and a portion of gene 10, in which 289 conditional lethal amber, opal, temperature sensitive and cold sensitive mutations are mapped into 44 small (several hundred base pair) intervals of known sequence. Knowledge of missense mutant phenotypes and information on the location of these mutations allows us to begin the assignment of partial protein functions to portions of these genes. The map and mapping strains will be of use in the further genetic dissection of the P22 DNA packaging and prohead assembly processes. PMID:2029965

The human serotonin N-acetyltransferase (EC 2.3.1.87) gene (AANAT): Structure, chromosomal localization, and tissue expression

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

Coon, S.L.; Bernard, M.; Roseboom, P.H.

Serotonin N-acetyltransferase (arylalkylamine N-acetyltransferase, AA-NAT, HGMW-approved symbol AANAT;EC 2.3.1.87) is the penultimate enzyme in melatonin synthesis and controls the night/day rhythm in melatonin production in the vertebrate pineal gland. We have found that the human AA-NAT gene spans {approx}2.5 kb, contains four exons, and is located at chromosome 17q25. The open reading frame encodes a 23.2-kDa protein that is {approx}80% identical to sheep and rat AA-NAT. The AA-NAT transcript ({approx}1 kb) is highly abundant in the pineal gland and is expressed at lower levels in the retina and in the Y79 retinoblastoma cell line. AA-NAT mRNA is also detectable atmore » low levels in several brain regions and the pituitary gland, but not in several peripheral tissues examined. Brain and pituitary AA-NAT could modulate serotonin-dependent aspects of human behavior and pituitary function. 31 refs., 5 figs.« less

Targeting vector construction through recombineering.

PubMed

Malureanu, Liviu A

2011-01-01

Gene targeting in mouse embryonic stem cells is an essential, yet still very expensive and highly time-consuming, tool and method to study gene function at the organismal level or to create mouse models of human diseases. Conventional cloning-based methods have been largely used for generating targeting vectors, but are hampered by a number of limiting factors, including the variety and location of restriction enzymes in the gene locus of interest, the specific PCR amplification of repetitive DNA sequences, and cloning of large DNA fragments. Recombineering is a technique that exploits the highly efficient homologous recombination function encoded by λ phage in Escherichia coli. Bacteriophage-based recombination can recombine homologous sequences as short as 30-50 bases, allowing manipulations such as insertion, deletion, or mutation of virtually any genomic region. The large availability of mouse genomic bacterial artificial chromosome (BAC) libraries covering most of the genome facilitates the retrieval of genomic DNA sequences from the bacterial chromosomes through recombineering. This chapter describes a successfully applied protocol and aims to be a detailed guide through the steps of generation of targeting vectors through recombineering.

Catabolite repression in Lactobacillus casei ATCC 393 is mediated by CcpA.

PubMed Central

Monedero, V; Gosalbes, M J; Pérez-Martínez, G

1997-01-01

The chromosomal ccpA gene from Lactobacillus casei ATCC 393 has been cloned and sequenced. It encodes the CcpA protein, a central catabolite regulator belonging to the LacI-GalR family of bacterial repressors, and shows 54% identity with CcpA proteins from Bacillus subtilis and Bacillus megaterium. The L. casei ccpA gene was able to complement a B. subtilis ccpA mutant. An L. casei ccpA mutant showed increased doubling times and a relief of the catabolite repression of some enzymatic activities, such as N-acetylglucosaminidase and phospho-beta-galactosidase. Detailed analysis of CcpA activity was performed by using the promoter region of the L. casei chromosomal lacTEGF operon which is subject to catabolite repression and contains a catabolite responsive element (cre) consensus sequence. Deletion of this cre site or the presence of the ccpA mutation abolished the catabolite repression of a lacp::gusA fusion. These data support the role of CcpA as a common regulatory element mediating catabolite repression in low-GC-content gram-positive bacteria. PMID:9352913

Genetic and physical mapping of 2q35 in the region of NRAMP and IL8R genes: Identification of a polymorphic repeat in exon 2 of NRAMP

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

White, J.K.; Shaw, M.A.; Barton, C.H.

1994-11-15

Recent interest has focused on the region of conserved synteny between mouse chromosome 1 and human 2q33-q37, particularly over the region encoding the murine macrophage resistance gene Ity/Lsh/Bcg (candidate Nramp) and members of the Il8r interleukin-8 (IL8) receptor gene cluster. In this paper, identification of a restriction fragment length polymorphism in the Il8RB gene in 35 pedigrees previously typed for markers in the 2q33-37 interval provided evidence (lod scores > 3) for linkage between Il8RB and the 2q34-135 markers FN1, TNP1, VIL1, and DES. Physical mapping, using yeast artificial chromosomes isolated with VIL1, confirmed that IL8RA, IL8RB and the IL8RBmore » pseudogene map within the NRAMP-VIL1 interval, with the physical distance (155 kb) from 5{prime} LSH to 3{prime} VIL1 representing {approx}3-fold that observed in the mouse. Partial sequencing of NRAMP confirmed the presence of the N-terminal proline/serine-rich putative SH3 binding domain in exon 2 of the human gene. Further analysis of Brazilian leprosy and visceral leishmaniasis pedigrees identified a rare second allele varying in a 9-nucleotide repeat motif of the exon 2 sequence but segregating independently of the disease phenotype. 38 refs., 4 figs., 3 tabs.« less

Segmenting the human genome based on states of neutral genetic divergence.

PubMed

Kuruppumullage Don, Prabhani; Ananda, Guruprasad; Chiaromonte, Francesca; Makova, Kateryna D

2013-09-03

Many studies have demonstrated that divergence levels generated by different mutation types vary and covary across the human genome. To improve our still-incomplete understanding of the mechanistic basis of this phenomenon, we analyze several mutation types simultaneously, anchoring their variation to specific regions of the genome. Using hidden Markov models on insertion, deletion, nucleotide substitution, and microsatellite divergence estimates inferred from human-orangutan alignments of neutrally evolving genomic sequences, we segment the human genome into regions corresponding to different divergence states--each uniquely characterized by specific combinations of divergence levels. We then parsed the mutagenic contributions of various biochemical processes associating divergence states with a broad range of genomic landscape features. We find that high divergence states inhabit guanine- and cytosine (GC)-rich, highly recombining subtelomeric regions; low divergence states cover inner parts of autosomes; chromosome X forms its own state with lowest divergence; and a state of elevated microsatellite mutability is interspersed across the genome. These general trends are mirrored in human diversity data from the 1000 Genomes Project, and departures from them highlight the evolutionary history of primate chromosomes. We also find that genes and noncoding functional marks [annotations from the Encyclopedia of DNA Elements (ENCODE)] are concentrated in high divergence states. Our results provide a powerful tool for biomedical data analysis: segmentations can be used to screen personal genome variants--including those associated with cancer and other diseases--and to improve computational predictions of noncoding functional elements.

Exception to the Rule: Genomic Characterization of Naturally Occurring Unusual Vibrio cholerae Strains with a Single Chromosome

DOE PAGES

Xie, Gary; Johnson, Shannon Lyn; Davenport, Karen Walston; ...

2017-08-29

Here, the genetic make-up of most bacteria is encoded in a single chromosome while about 10% have more than one chromosome. Among these, Vibrio cholerae, with two chromosomes, has served as a model system to study various aspects of chromosome maintenance, mainly replication, and faithful partitioning of multipartite genomes. Here, we describe the genomic characterization of strains that are an exception to the two chromosome rules: naturally occurring single-chromosome V. cholerae. Whole genome sequence analyses of NSCV1 and NSCV2 (natural single-chromosome vibrio) revealed that the Chr1 and Chr2 fusion junctions contain prophages, IS elements, and direct repeats, in addition tomore » large-scale chromosomal rearrangements such as inversions, insertions, and long tandem repeats elsewhere in the chromosome compared to prototypical two chromosome V. cholerae genomes. Many of the known cholera virulence factors are absent. The two origins of replication and associated genes are generally intact with synonymous mutations in some genes, as arerecAand mismatch repair (MMR) genes dam, mutH, and mutL; MutS function is probably impaired in NSCV2. These strains are ideal tools for studying mechanistic aspects of maintenance of chromosomes with multiple origins and other rearrangements and the biological, functional, and evolutionary significance of multipartite genome architecture in general.« less

Exception to the Rule: Genomic Characterization of Naturally Occurring Unusual Vibrio cholerae Strains with a Single Chromosome

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

Xie, Gary; Johnson, Shannon Lyn; Davenport, Karen Walston

Here, the genetic make-up of most bacteria is encoded in a single chromosome while about 10% have more than one chromosome. Among these, Vibrio cholerae, with two chromosomes, has served as a model system to study various aspects of chromosome maintenance, mainly replication, and faithful partitioning of multipartite genomes. Here, we describe the genomic characterization of strains that are an exception to the two chromosome rules: naturally occurring single-chromosome V. cholerae. Whole genome sequence analyses of NSCV1 and NSCV2 (natural single-chromosome vibrio) revealed that the Chr1 and Chr2 fusion junctions contain prophages, IS elements, and direct repeats, in addition tomore » large-scale chromosomal rearrangements such as inversions, insertions, and long tandem repeats elsewhere in the chromosome compared to prototypical two chromosome V. cholerae genomes. Many of the known cholera virulence factors are absent. The two origins of replication and associated genes are generally intact with synonymous mutations in some genes, as arerecAand mismatch repair (MMR) genes dam, mutH, and mutL; MutS function is probably impaired in NSCV2. These strains are ideal tools for studying mechanistic aspects of maintenance of chromosomes with multiple origins and other rearrangements and the biological, functional, and evolutionary significance of multipartite genome architecture in general.« less

Genomic analysis of the chromosome 15q11-q13 Prader-Willi syndrome region and characterization of transcripts for GOLGA8E and WHCD1L1 from the proximal breakpoint region.

PubMed

Jiang, Yong-Hui; Wauki, Kekio; Liu, Qian; Bressler, Jan; Pan, Yanzhen; Kashork, Catherine D; Shaffer, Lisa G; Beaudet, Arthur L

2008-01-28

Prader-Willi syndrome (PWS) is a neurobehavioral disorder characterized by neonatal hypotonia, childhood obesity, dysmorphic features, hypogonadism, mental retardation, and behavioral problems. Although PWS is most often caused by a paternal interstitial deletion of a 6-Mb region of chromosome 15q11-q13, the identity of the exact protein coding or noncoding RNAs whose deficiency produces the PWS phenotype is uncertain. There are also reports describing a PWS-like phenotype in a subset of patients with full mutations in the FMR1 (fragile X mental retardation 1) gene. Taking advantage of the human genome sequence, we have performed extensive sequence analysis and molecular studies for the PWS candidate region. We have characterized transcripts for the first time for two UCSC Genome Browser predicted protein-coding genes, GOLGA8E (golgin subfamily a, 8E) and WHDC1L1 (WAS protein homology region containing 1-like 1) and have further characterized two previously reported genes, CYF1P1 and NIPA2; all four genes are in the region close to the proximal/centromeric deletion breakpoint (BP1). GOLGA8E belongs to the golgin subfamily of coiled-coil proteins associated with the Golgi apparatus. Six out of 16 golgin subfamily proteins in the human genome have been mapped in the chromosome 15q11-q13 and 15q24-q26 regions. We have also identified more than 38 copies of GOLGA8E-like sequence in the 15q11-q14 and 15q23-q26 regions which supports the presence of a GOLGA8E-associated low copy repeat (LCR). Analysis of the 15q11-q13 region by PFGE also revealed a polymorphic region between BP1 and BP2. WHDC1L1 is a novel gene with similarity to mouse Whdc1 (WAS protein homology region 2 domain containing 1) and human JMY protein (junction-mediating and regulatory protein). Expression analysis of cultured human cells and brain tissues from PWS patients indicates that CYFIP1 and NIPA2 are biallelically expressed. However, we were not able to determine the allele-specific expression pattern for GOLGA8E and WHDC1L1 because these two genes have highly related sequences that might also be expressed. We have presented an updated version of a sequence-based physical map for a complex chromosomal region, and we raise the possibility of polymorphism in the genomic orientation of the BP1 to BP2 region. The identification of two new proteins GOLGA8E and WHDC1L1 encoded by genes in the 15q11-q13 region may extend our understanding of the molecular basis of PWS. In terms of copy number variation and gene organization, this is one of the most polymorphic regions of the human genome, and perhaps the single most polymorphic region of this type.

Identification of genes from the Treacher Collins candidate region

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

Dixon, M.; Dixon, J.; Edwards, S.

Treacher Collins syndrome (TCOF1) is an autosomal dominant disorder of craniofacial development. The TCOF1 locus has previously been mapped to chromosome 5q32-33. The candidate gene region has been defined as being between two flanking markers, ribosomal protein S14 (RPS14) and Annexin 6 (ANX6), by analyzing recombination events in affected individuals. It is estimated that the distance between these flanking markers is 500 kb by three separate analysis methods: (1) radiation hybrid mapping; (2) genetic linkage; and (3) YAC contig analysis. A cosmid contig which spans the candidate gene region for TCOF1 has been constructed by screening the Los Alamos Nationalmore » Laboratory flow-sorted chromosome 5 cosmid library. Cosmids were obtained by using a combination of probes generated from YAC end clones, Alu-PCR fragments from YACs, and asymmetric PCR fragments from both T7 and T3 cosmid ends. Exon amplifications, the selection of genomic coding sequences based upon the presence of functional splice acceptor and donor sites, was used to identify potential exon sequences. Sequences found to be conserved between species were then used to screen cDNA libraries in order to identify candidate genes. To date, four different cDNAs have been isolated from this region and are being analyzed as potential candidate genes for TCOF1. These include the genes encoding plasma glutathione peroxidase (GPX3), heparin sulfate sulfotransferase (HSST), a gene with homology to the ETS family of proteins and one which shows no homology to any known genes. Work is also in progress to identify and characterize additional cDNAs from the candidate gene region.« less

Human ESP1/CRP2, a member of the LIM domain protein family: Characterization of the cDNA and assignment of the gene locus to chromosome 14q32.3

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

Karim, Mohammad Azharul; Ohta, Kohji; Matsuda, Ichiro

1996-01-15

The LIM domain is present in a wide variety of proteins with diverse functions and exhibits characteristic arrangements of Cys and His residues with a novel zinc-binding motif. LIM domain proteins have been implicated in development, cell regulation, and cell structure. A LIM domain protein was identified by screening a human cDNA library with rat cysteine-rich intestinal protein (CRIP) as a probe, under conditions of low stringency. Comparison of the predicted amino acid sequence with several LIM domain proteins revealed 93% of the residues to be identical to rat LIM domain protein, termed ESP1 or CRP2. Thus, the protein ismore » hereafter referred to as human ESP1/CRP2. The cDNA encompasses a 1171-base region, including 26, 624, and 521 bases in the 5{prime}-noncoding region, coding region, and 3{prime}-noncoding regions, respectively, and encodes the entire ESP1/CRP2 protein has two LIM domains, and each shares 35.1% and 77 or 79% identical residues with human cysteine-rich protein (CRP) and rat CRIP, respectively. Northern blot analysis of ESP1/CRP2 in various human tissues showed distinct tissue distributions compared with CRP and CRIP, suggesting that each might serve related but specific roles in tissue organization or function. Using a panel of human-rodent somatic cell hybrids, the ESP1/CRP2 locus was assigned to chromosome 14. Fluorescence in situ hybridization, using cDNA and a genome DNA fragment of the ESP1/CRP2 as probes, confirms this assignment and relegates regional localization to band 14q32.3 47 refs., 7 figs.« less

Chronic Myeloid Leukemia in the Era of Tyrosine Kinase Inhibitors: An Evolving Paradigm of Molecularly Targeted Therapy.

PubMed

Ali, Mohamed A M

2016-08-01

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm, characterized by the unrestrained expansion of pluripotent hematopoietic stem cells. CML was the first malignancy in which a unique chromosomal abnormality was identified and a pathophysiologic association was suggested. The hallmark of CML is a reciprocal chromosomal translocation between the long arms of chromosomes 9 and 22, t(9; 22)(q34; q11), creating a derivative 9q+ and a shortened 22q-. The latter, known as the Philadelphia (Ph) chromosome, harbors the breakpoint cluster region-abelson (BCR-ABL) fusion gene, encoding the constitutively active BCR-ABL tyrosine kinase that is necessary and sufficient for initiating CML. The successful implementation of tyrosine kinase inhibitors (TKIs) for the treatment of CML remains a flagship for molecularly targeted therapy in cancer. TKIs have changed the clinical course of CML; however, some patients nonetheless demonstrate primary or secondary resistance to such therapy and require an alternative therapeutic strategy. Therefore, the assessment of early response to treatment with TKIs has become an important tool in the clinical monitoring of CML patients. Although mutations in the BCR-ABL have proven to be the most prominent mechanism of resistance to TKIs, other mechanisms-either rendering the leukemic cells still dependent on BCR-ABL activity or supporting oncogenic properties of the leukemic cells independent of BCR-ABL signaling-have been identified. This article provides an overview of the current understanding of CML pathogenesis; recommendations for diagnostic tools, treatment strategies, and management guidelines; and highlights the BCR-ABL-dependent and -independent mechanisms that contribute to the development of resistance to TKIs.

Recent Sex Chromosome Divergence despite Ancient Dioecy in the Willow Salix viminalis

PubMed Central

Pucholt, Pascal; Wright, Alison E.; Conze, Lei Liu; Mank, Judith E.; Berlin, Sofia

2017-01-01

Abstract Sex chromosomes can evolve when recombination is halted between a pair of chromosomes, and this can lead to degeneration of the sex-limited chromosome. In the early stages of differentiation sex chromosomes are homomorphic, and even though homomorphic sex chromosomes are very common throughout animals and plants, we know little about the evolutionary forces shaping these types of sex chromosomes. We used DNA- and RNA-Seq data from females and males to explore the sex chromosomes in the female heterogametic willow, Salix viminalis, a species with ancient dioecy but with homomorphic sex chromosomes. We detected no major sex differences in read coverage in the sex determination (SD) region, indicating that the W region has not significantly degenerated. However, single nucleotide polymorphism densities in the SD region are higher in females compared with males, indicating very recent recombination suppression, followed by the accumulation of sex-specific single nucleotide polymorphisms. Interestingly, we identified two female-specific scaffolds that likely represent W-chromosome-specific sequence. We show that genes located in the SD region display a mild excess of male-biased expression in sex-specific tissue, and we use allele-specific gene expression analysis to show that this is the result of masculinization of expression on the Z chromosome rather than degeneration of female-expression on the W chromosome. Together, our results demonstrate that insertion of small DNA fragments and accumulation of sex-biased gene expression can occur before the detectable decay of the sex-limited chromosome. PMID:28453634

Six Things Everyone Should Know About Genetics

MedlinePlus

... The most important molecules encoded by genes are RNA and proteins. Gene - the functional and physical unit ... the chromosome is the book itself. Proteins and RNA influence how an organism looks, how well its ...

Suppression of a NAC-like transcription factor gene improves boron-toxicity tolerance in rice.

PubMed

Ochiai, Kumiko; Shimizu, Akifumi; Okumoto, Yutaka; Fujiwara, Toru; Matoh, Toru

2011-07-01

We identified a gene responsible for tolerance to boron (B) toxicity in rice (Oryza sativa), named BORON EXCESS TOLERANT1. Using recombinant inbred lines derived from the B-toxicity-sensitive indica-ecotype cultivar IR36 and the tolerant japonica-ecotype cultivar Nekken 1, the region responsible for tolerance to B toxicity was narrowed to 49 kb on chromosome 4. Eight genes are annotated in this region. The DNA sequence in this region was compared between the B-toxicity-sensitive japonica cultivar Wataribune and the B-toxicity-tolerant japonica cultivar Nipponbare by eco-TILLING analysis and revealed a one-base insertion mutation in the open reading frame sequence of the gene Os04g0477300. The gene encodes a NAC (NAM, ATAF, and CUC)-like transcription factor and the function of the transcript is abolished in B-toxicity-tolerant cultivars. Transgenic plants in which the expression of Os04g0477300 is abolished by RNA interference gain tolerance to B toxicity.

Suppression of a NAC-Like Transcription Factor Gene Improves Boron-Toxicity Tolerance in Rice1

PubMed Central

Ochiai, Kumiko; Shimizu, Akifumi; Okumoto, Yutaka; Fujiwara, Toru; Matoh, Toru

2011-01-01

We identified a gene responsible for tolerance to boron (B) toxicity in rice (Oryza sativa), named BORON EXCESS TOLERANT1. Using recombinant inbred lines derived from the B-toxicity-sensitive indica-ecotype cultivar IR36 and the tolerant japonica-ecotype cultivar Nekken 1, the region responsible for tolerance to B toxicity was narrowed to 49 kb on chromosome 4. Eight genes are annotated in this region. The DNA sequence in this region was compared between the B-toxicity-sensitive japonica cultivar Wataribune and the B-toxicity-tolerant japonica cultivar Nipponbare by eco-TILLING analysis and revealed a one-base insertion mutation in the open reading frame sequence of the gene Os04g0477300. The gene encodes a NAC (NAM, ATAF, and CUC)-like transcription factor and the function of the transcript is abolished in B-toxicity-tolerant cultivars. Transgenic plants in which the expression of Os04g0477300 is abolished by RNA interference gain tolerance to B toxicity. PMID:21543724

Recombinant cells that highly express chromosomally-integrated heterologous genes

DOEpatents

Ingram, L.O.; Ohta, Kazuyoshi; Wood, B.E.

1998-10-13

Recombinant host cells are obtained that comprise (A) a heterologous, polypeptide-encoding polynucleotide segment, stably integrated into a chromosome, which is under transcriptional control of an endogenous promoter and (B) a mutation that effects increased expression of the heterologous segment, resulting in enhanced production by the host cells of each polypeptide encoded by that segment, relative to production of each polypeptide by the host cells in the absence of the mutation. The increased expression thus achieved is retained in the absence of conditions that select for cells displaying such increased expression. When the integrated segment comprises, for example, ethanol-production genes from an efficient ethanol producer like Zymomonas mobilis, recombinant Escherichia coli and other enteric bacterial cells within the present invention are capable of converting a wide range of biomass-derived sugars efficiently to ethanol. 13 figs.

Recombinant cells that highly express chromosomally-integrated heterologous genes

DOEpatents

Ingram, Lonnie O.; Ohta, Kazuyoshi; Wood, Brent E.

1998-01-01

Recombinant host cells are obtained that comprise (A) a heterologous, polypeptide-encoding polynucleotide segment, stably integrated into a chromosome, which is under transcriptional control of an endogenous promoter and (B) a mutation that effects increased expression of the heterologous segment, resulting in enhanced production by the host cells of each polypeptide encoded by that segment, relative to production of each polypeptide by the host cells in the absence of the mutation. The increased expression thus achieved is retained in the absence of conditions that select for cells displaying such increased expression. When the integrated segment comprises, for example, ethanol-production genes from an efficient ethanol producer like Zymomonas mobilis, recombinant Escherichia coli and other enteric bacterial cells within the present invention are capable of converting a wide range of biomass-derived sugars efficiently to ethanol.

Recombinant cells that highly express chromosomally-integrated heterologous gene

DOEpatents

Ingram, Lonnie O.; Ohta, Kazuyoshi; Wood, Brent E.

2007-03-20

Recombinant host cells are obtained that comprise (A) a heterologous, polypeptide-encoding polynucleotide segment, stably integrated into a chromosome, which is under transcriptional control of an endogenous promoter and (B) a mutation that effects increased expression of the heterologous segment, resulting in enhanced production by the host cells of each polypeptide encoded by that segment, relative to production of each polypeptide by the host cells in the absence of the mutation. The increased expression thus achieved is retained in the absence of conditions that select for cells displaying such increased expression. When the integrated segment comprises, for example, ethanol-production genes from an efficient ethanol producer like Zymomonas mobilis, recombinant Escherichia coli and other enteric bacterial cells within the present invention are capable of converting a wide range of biomass-derived sugars efficiently to ethanol.

Recombinant cells that highly express chromosomally-integrated heterologous genes

DOEpatents

Ingram, Lonnie O.; Ohta, Kazuyoshi; Wood, Brent E.

2000-08-22

Recombinant host cells are obtained that comprise (A) a heterologous, polypeptide-encoding polynucleotide segment, stably integrated into a chromosome, which is under transcriptional control of an endogenous promoter and (B) a mutation that effects increased expression of the heterologous segment, resulting in enhanced production by the host cells of each polypeptide encoded by that segment, relative to production of each polypeptide by the host cells in the absence of the mutation. The increased expression thus achieved is retained in the absence of conditions that select for cells displaying such increased expression. When the integrated segment comprises, for example, ethanol-production genes from an efficient ethanol producer like Zymomonas mobilis, recombinant Escherichia coli and other enteric bacterial cells within the present invention are capable of converting a wide range of biomass-derived sugars efficiently to ethanol.

Endoribonuclease type II toxin-antitoxin systems: functional or selfish?

PubMed

Ramisetty, Bhaskar Chandra Mohan; Santhosh, Ramachandran Sarojini

2017-07-01

Most bacterial genomes have multiple type II toxin-antitoxin systems (TAs) that encode two proteins which are referred to as a toxin and an antitoxin. Toxins inhibit a cellular process, while the interaction of the antitoxin with the toxin attenuates the toxin's activity. Endoribonuclease-encoding TAs cleave RNA in a sequence-dependent fashion, resulting in translational inhibition. To account for their prevalence and retention by bacterial genomes, TAs are credited with clinically significant phenomena, such as bacterial programmed cell death, persistence, biofilms and anti-addiction to plasmids. However, the programmed cell death and persistence hypotheses have been challenged because of conceptual, methodological and/or strain issues. In an alternative view, chromosomal TAs seem to be retained by virtue of addiction at two levels: via a poison-antidote combination (TA proteins) and via transcriptional reprogramming of the downstream core gene (due to integration). Any perturbation in the chromosomal TA operons could cause fitness loss due to polar effects on the downstream genes and hence be detrimental under natural conditions. The endoribonucleases encoding chromosomal TAs are most likely selfish DNA as they are retained by bacterial genomes, even though TAs do not confer a direct advantage via the TA proteins. TAs are likely used by various replicons as 'genetic arms' that allow the maintenance of themselves and associated genetic elements. TAs seem to be the 'selfish arms' that make the best use of the 'arms race' between bacterial genomes and plasmids.

Comparative Maps of Human 19p13.3 and Mouse Chromosome 10 Allow Identification of Sequences at Evolutionary Breakpoints

PubMed Central

Puttagunta, Radhika; Gordon, Laurie A.; Meyer, Gary E.; Kapfhamer, David; Lamerdin, Jane E.; Kantheti, Prameela; Portman, Kathleen M.; Chung, Wendy K.; Jenne, Dieter E.; Olsen, Anne S.; Burmeister, Margit

2000-01-01

A cosmid/bacterial artificial chromosome (BAC) contiguous (contig) map of human chromosome (HSA) 19p13.3 has been constructed, and over 50 genes have been localized to the contig. Genes and anonymous ESTs from ≈4000 kb of human 19p13.3 were placed on the central mouse chromosome 10 map by genetic mapping and pulsed-field gel electrophoresis (PFGE) analysis. A region of ∼2500 kb of HSA 19p13.3 is collinear to mouse chromosome (MMU) 10. In contrast, the adjacent ≈1200 kb are inverted. Two genes are located in a 50-kb region after the inversion on MMU 10, followed by a region of homology to mouse chromosome 17. The synteny breakpoint and one of the inversion breakpoints has been localized to sequenced regions in human <5 kb in size. Both breakpoints are rich in simple tandem repeats, including (TCTG)n, (CT)n, and (GTCTCT)n, suggesting that simple repeat sequences may be involved in chromosome breaks during evolution. The overall size of the region in mouse is smaller, although no large regions are missing. Comparing the physical maps to the genetic maps showed that in contrast to the higher-than-average rate of genetic recombination in gene-rich telomeric region on HSA 19p13.3, the average rate of recombination is lower than expected in the homologous mouse region. This might indicate that a hot spot of recombination may have been lost in mouse or gained in human during evolution, or that the position of sequences along the chromosome (telomeric compared to the middle of a chromosome) is important for recombination rates. PMID:10984455

Gamma-ray mutagenesis studies in a new human-hamster hybrid, A(L)CD59(+/-), which has two human chromosomes 11 but is hemizygous for the CD59 gene

NASA Technical Reports Server (NTRS)

Kraemer, S. M.; Vannais, D. B.; Kronenberg, A.; Ueno, A.; Waldren, C. A.; Chatterjee, A. (Principal Investigator)

2001-01-01

Kraemer, S. M., Vannais, D. B., Kronenberg, A., Ueno, A. and Waldren, C. A. Gamma-Ray Mutagenesis Studies in a New Human-Hamster Hybrid, A(L)CD59(+/-), which has Two Human Chromosomes 11 but is Hemizygous for the CD59 Gene. Radiat. Res. 156, 10-19 (2001).We have developed a human-CHO hybrid cell line, named A(L)CD59(+/-), which has two copies of human chromosome 11 but is hemizygous for the CD59 gene and the CD59 cell surface antigen that it encodes. Our previous studies used the A(L) and A(L)C hybrids that respectively contain one or two sets of CHO chromosomes plus a single copy of human chromosome 11. The CD59 gene at 11p13.5 and the CD59 antigen encoded by it are the principal markers used in our mutagenesis studies. The hybrid A(L)CD59(+/-) contains two copies of human chromosome 11, only one of which carries the CD59 gene. The incidence of CD59 (-) mutants (formerly called S1(-)) induced by (137)Cs gamma rays is about fivefold greater in A(L)CD59(+/-) cells than in A(L) cells. Evidence is presented that this increase in mutant yield is due to the increased induction of certain classes of large chromosomal mutations that are lethal to A(L) cells but are tolerated in the A(L)CD59(+/-) hybrid. In addition, significantly more of the CD59 (-) mutants induced by (137)Cs gamma rays in A(L)CD59(+/-) cells display chromosomal instability than in A(L) cells. On the other hand, the yield of gamma-ray-induced CD59 (-) mutants in A(L)CD59(+/-) cells is half that of the A(L)C hybrid, which also tolerates very large mutations but has only one copy of human chromosome 11. We interpret the difference in mutability as evidence that repair processes involving the homologous chromosomes 11 play a role in determining mutant yields. The A(L)CD59(+/-) hybrid provides a useful new tool for quantifying mutagenesis and shedding light on mechanisms of genetic instability and mutagenesis.

Unusual 4p16.3 deletions suggest an additional chromosome region for the Wolf-Hirschhorn syndrome-associated seizures disorder.

PubMed

Zollino, Marcella; Orteschi, Daniela; Ruiter, Mariken; Pfundt, Rolph; Steindl, Katharina; Cafiero, Concetta; Ricciardi, Stefania; Contaldo, Ilaria; Chieffo, Daniela; Ranalli, Domiziana; Acquafondata, Celeste; Murdolo, Marina; Marangi, Giuseppe; Asaro, Alessia; Battaglia, Domenica

2014-06-01

Seizure disorder is one of the most relevant clinical manifestations in Wolf-Hirschhorn syndrome (WHS) and it acts as independent prognostic factor for the severity of intellectual disability (ID). LETM1, encoding a mitochondrial protein playing a role in K(+) /H(+) exchange and in Ca(2+) homeostasis, is currently considered the major candidate gene. However, whether haploinsufficiency limited to LETM1 is enough to cause epilepsy is still unclear. The main purpose of the present research is to define the 4p chromosome regions where genes for seizures reside. Comparison of our three unusual 4p16.3 deletions with 13 literature reports. Array-comparative genomic hybridization (a-CGH). Real-time polymerase chain reaction (RT-PCR) on messanger RNA (mRNA) of LETM1 and CPLX1. Direct sequencing of LETM1. Three unusual 4p16.3 deletions were detected by array-CGH in absence of a obvious clinical diagnosis of WHS. Two of these, encompassing LETM1, were found in subjects who never had seizures. The deletions were interstitial, spanning 1.1 Mb with preservation of the terminal 1.77 Mb region in one case and 0.84 Mb with preservation of the terminal 1.07 Mb region in the other. The other deletion was terminal, affecting a 0.564 Mb segment, with preservation of LETM1, and it was associated with seizures and learning difficulties. Upon evaluating our patients along with literature reports, we noted that six of eight subjects with terminal 4p deletions preserving LETM1 had seizures, whereas seven of seven with interstitial deletions including LETM1 and preserving the terminal 1 Mb region on 4p did not. An additional chromosome region for seizures is suggested, falling within the terminal 1.5 Mb on 4p, not including LETM1. We consider that haploinsufficiency not limited to LETM1 but including other genes acts as a risk factor for the WHS-associated seizure disorder, according to a comorbidity model of pathogenesis. Additional candidate genes reside in the terminal 1.5 Mb region on 4p, most likely distal to LETM1. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here. Wiley Periodicals, Inc. © 2014 International League Against Epilepsy.

Preferrential rearrangement in normal rabbits of the 3' VHa allotype gene that is deleted in Alicia mutants; somatic hypermutation/conversion may play a major role in generating the heterogeneity of rabbit heavy chain variable region sequences.

PubMed

Allegrucci, M; Young-Cooper, G O; Alexander, C B; Newman, B A; Mage, R G

1991-02-01

The rabbit is unique in having well-defined allotypes in the variable region of the heavy chain. Products of the VHa locus, (with alleles a1, a2, and a3), account for the majority of the serum immunoglobulins. A small percentage of the serum immunoglobulins are a-negative. In 1986, Kelus and Weiss described a mutation that depressed the expression of the Ig VH a2 genes in an a1/a2 rabbit. From this animal the Alicia rabbit strain was developed and the mutation was termed ali. We previously showed, using Southern analysis and the transverse alternating field electrophoresis technique, that the difference between the ali rabbit and normal is a relatively small deletion including some of the most 3' VH genes. The most JH proximal 3' VH1 genes in DNA from normal rabbits of a1, a2 and a3 haplotypes encode a1, a2 and a3 molecules respectively, and it has been suggested that these genes are responsible for allelic inheritance of VHa allotypes. The present study suggests that the 3' end of the VH locus probably plays a key role in regulation of VH gene expression in rabbits because VH gene(s) in this region are the target(s) of preferential VDJ rearrangements. This raises the possibility that mechanisms such as somatic gene conversion and hypermutation are at work to generate the antibody repertoire in this species. Our data support the view that the 3' VH1 gene may be the preferred target for rearrangement in normal rabbits, and for the normal chromosome in heterozygous ali animals. However, homozygous ali rabbits with a deletion that removed the a2-encoding VH1 on both chromosomes do survive, rearrange other VH genes and produce normal levels of immunoglobulins as well as a significant percentage of B cells which bear the a2 allotype. This challenges the view that one VH gene, VH1, is solely responsible for the inheritance pattern of VHa allotypes.

Proteome approaches to characterize seed storage proteins related to ditelocentric chromosomes in common wheat (Triticum aestivum L.).

PubMed

Islam, Nazrul; Woo, Sun-Hee; Tsujimoto, Hisashi; Kawasaki, Hiroshi; Hirano, Hisashi

2002-09-01

Changes in protein composition of wheat endosperm proteome were investigated in 39 ditelocentric chromosome lines of common wheat (Triticum aestivum L.) cv. Chinese Spring. Two-dimensional gel electrophoresis followed by Coomassie Brilliant Blue staining has resolved a total of 105 protein spots in a gel. Quantitative image analysis of protein spots was performed by PDQuest. Variations in protein spots between the euploid and the 39 ditelocentric lines were evaluated by spot number, appearance, disappearance and intensity. A specific spot present in all gels was taken as an internal standard, and the intensity of all other spots was calculated as the ratio of the internal standard. Out of the 1755 major spots detected in 39 ditelocentric lines, 1372 (78%) spots were found variable in different spot parameters: 147 (11%) disappeared, 978 (71%) up-regulated and 247 (18%) down-regulated. Correlation studies in changes in protein intensities among 24 protein spots across the ditelocentric lines were performed. High correlations in changes of protein intensities were observed among the proteins encoded by genes located in the homoeologous arms. Locations of structural genes controlling 26 spots were identified in 10 chromosomal arms. Multiple regulators of the same protein located at various chromosomal arms were also noticed. Identification of structural genes for most of the proteins was found difficult due to multiple regulators encoding the same protein. Two novel subunits (1B(Z,) 1BDz), the structure of which are very similar to the high molecular weight glutenin subunit 12, were identified, and the chromosome arm locations of these subunits were assigned.

The Drosophila homolog of Down's syndrome critical region 1 gene regulates learning: Implications for mental retardation

PubMed Central

Chang, Karen T.; Shi, Yi-Jun; Min, Kyung-Tai

2003-01-01

Mental retardation is the most common phenotypic abnormality seen in Down's syndrome (DS) patients, yet the underlying mechanism remains mysterious. DS critical region 1 (DSCR1), located on chromosome 21, is overexpressed in the brain of DS fetus and encodes an inhibitor of calcineurin, but its physiological significance is unknown. To study its functional importance and role in mental retardation in DS, we generated Drosophila mutants of nebula, an ortholog of human DSCR1. Here, we report that both nebula loss-of-function and overexpression mutants exhibit severe learning defects that are attributed by biochemical perturbations rather than maldevelopment of the brain. These results, combined with our data showing that the same biochemical signaling pathway is altered in human DS fetal brain tissue overexpressing DSCR1, suggest that alteration of DSCR1 expression could contribute to mental retardation in DS. PMID:14668437

A Rehabilitation of the Genetic Map of the 84b-D Region in DROSOPHILA MELANOGASTER

PubMed Central

Cavener, Douglas R.; Otteson, Deborah C.; Kaufman, Thomas C.

1986-01-01

A reanalysis of the 84B3 to 84B3,5 region of the polytene chromosomes of Drosophila melanogaster has led to the identification and localization of 16 genes. These genes include 11 vital loci, four genes exhibiting nonlethal visible mutant phenotypes and one gene encoding a nonessential enzyme. The identity of the gene products of two of the vital genes has been determined to be α-tubulin and glucose dehydrogenase (Gld). Three newly identified genes, sticking (stk), half out ( hat) and trapped (ted), as well as Gld are required for eclosion. Among the nonessential genes are roughened eye (roe) and ruffed eye (rue), which affect eye texture. The roe phenotype is greatly enhanced by deletions that simultaneously remove roe and an unidentified locus in 84E. Mutations in another nonessential gene, rotund (rn), are characterized by pattern deletions of most adult appendages. PMID:3095179

Effects of human chromosome 12 on interactions between Tat and TAR of human immunodeficiency virus type 1.

PubMed Central

Alonso, A; Cujec, T P; Peterlin, B M

1994-01-01

Rates of transcriptions of the human immunodeficiency virus are greatly increased by the viral trans activator Tat. In vitro, Tat binds to the 5' bulge of the trans-activation response (TAR) RNA stem-loop, which is present in all viral transcripts. In human cells, the central loop in TAR and its cellular RNA-binding proteins are also critical for the function of Tat. Previously, we demonstrated that in rodent cells (CHO cells), but not in those which contain the human chromosome 12 (CHO12 cells), Tat-TAR interactions are compromised. In this study, we examined the roles of the bulge and loop in TAR in Tat trans activation in these cells. Whereas low levels of trans activation depended solely on interactions between Tat and the bulge in CHO cells, high levels of trans activation depended also on interactions between Tat and the loop in CHO12 cells. Since the TAR loop binding proteins in these two cell lines were identical and different from their human counterpart, the human chromosome 12 does not encode TAR loop binding proteins. In vivo binding competition studies with TAR decoys confirmed that the binding of Tat to TAR is more efficient in CHO12 cells. Thus, the protein(s) encoded on human chromosome 12 helps to tether Tat to TAR via its loop, which results in high levels of trans activation. Images PMID:8083988

Genetic Characterization of a Sinorhizobium meliloti Chromosomal Region Involved in Lipopolysaccharide Biosynthesis

PubMed Central

Lagares, Antonio; Hozbor, Daniela F.; Niehaus, Karsten; Otero, Augusto J. L. Pich; Lorenzen, Jens; Arnold, Walter; Pühler, Alfred

2001-01-01

The genetic characterization of a 5.5-kb chromosomal region of Sinorhizobium meliloti 2011 that contains lpsB, a gene required for the normal development of symbiosis with Medicago spp., is presented. The nucleotide sequence of this DNA fragment revealed the presence of six genes: greA and lpsB, transcribed in the forward direction; and lpsE, lpsD, lpsC, and lrp, transcribed in the reverse direction. Except for lpsB, none of the lps genes were relevant for nodulation and nitrogen fixation. Analysis of the transcriptional organization of lpsB showed that greA and lpsB are part of separate transcriptional units, which is in agreement with the finding of a DNA stretch homologous to a “nonnitrogen” promoter consensus sequence between greA and lpsB. The opposite orientation of lpsB with respect to its first downstream coding sequence, lpsE, indicated that the altered LPS and the defective symbiosis of lpsB mutants are both consequences of a primary nonpolar defect in a single gene. Global sequence comparisons revealed that the greA-lpsB and lrp genes of S. meliloti have a genetic organization similar to that of their homologous loci in R. leguminosarum bv. viciae. In particular, high sequence similarity was found between the translation product of lpsB and a core-related biosynthetic mannosyltransferase of R. leguminosarum bv. viciae encoded by the lpcC gene. The functional relationship between these two genes was demonstrated in genetic complementation experiments in which the S. meliloti lpsB gene restored the wild-type LPS phenotype when introduced into lpcC mutants of R. leguminosarum. These results support the view that S. meliloti lpsB also encodes a mannosyltransferase that participates in the biosynthesis of the LPS core. Evidence is provided for the presence of other lpsB-homologous sequences in several members of the family Rhizobiaceae. PMID:11157937

SPK1 is an essential S-phase-specific gene of Saccharomyces cerevisiae that encodes a nuclear serine/threonine/tyrosine kinase.

PubMed

Zheng, P; Fay, D S; Burton, J; Xiao, H; Pinkham, J L; Stern, D F

1993-09-01

SPK1 was originally discovered in an immunoscreen for tyrosine-protein kinases in Saccharomyces cerevisiae. We have used biochemical and genetic techniques to investigate the function of this gene and its encoded protein. Hybridization of an SPK1 probe to an ordered genomic library showed that SPK1 is adjacent to PEP4 (chromosome XVI L). Sporulation of spk1/+ heterozygotes gave rise to spk1 spores that grew into microcolonies but could not be further propagated. These colonies were greatly enriched for budded cells, especially those with large buds. Similarly, eviction of CEN plasmids bearing SPK1 from cells with a chromosomal SPK1 disruption yielded viable cells with only low frequency. Spk1 protein was identified by immunoprecipitation and immunoblotting. It was associated with protein-Ser, Thr, and Tyr kinase activity in immune complex kinase assays. Spk1 was localized to the nucleus by immunofluorescence. The nucleotide sequence of the SPK1 5' noncoding region revealed that SPK1 contains two MluI cell cycle box elements. These elements confer S-phase-specific transcription to many genes involved in DNA synthesis. Northern (RNA) blotting of synchronized cells verified that the SPK1 transcript is coregulated with other MluI box-regulated genes. The SPK1 upstream region also includes a domain highly homologous to sequences involved in induction of RAD2 and other excision repair genes by agents that induce DNA damage. spk1 strains were hypersensitive to UV irradiation. Taken together, these findings indicate that SPK1 is a dual-specificity (Ser/Thr and Tyr) protein kinase that is essential for viability. The cell cycle-dependent transcription, presence of DNA damage-related sequences, requirement for UV resistance, and nuclear localization of Spk1 all link this gene to a crucial S-phase-specific role, probably as a positive regulator of DNA synthesis.

Allelic diversity in an NLR gene BPH9 enables rice to combat planthopper variation.

PubMed

Zhao, Yan; Huang, Jin; Wang, Zhizheng; Jing, Shengli; Wang, Yang; Ouyang, Yidan; Cai, Baodong; Xin, Xiu-Fang; Liu, Xin; Zhang, Chunxiao; Pan, Yufang; Ma, Rui; Li, Qiaofeng; Jiang, Weihua; Zeng, Ya; Shangguan, Xinxin; Wang, Huiying; Du, Bo; Zhu, Lili; Xu, Xun; Feng, Yu-Qi; He, Sheng Yang; Chen, Rongzhi; Zhang, Qifa; He, Guangcun

2016-10-24

Brown planthopper (BPH), Nilaparvata lugens Stål, is one of the most devastating insect pests of rice (Oryza sativa L.). Currently, 30 BPH-resistance genes have been genetically defined, most of which are clustered on specific chromosome regions. Here, we describe molecular cloning and characterization of a BPH-resistance gene, BPH9, mapped on the long arm of rice chromosome 12 (12L). BPH9 encodes a rare type of nucleotide-binding and leucine-rich repeat (NLR)-containing protein that localizes to the endomembrane system and causes a cell death phenotype. BPH9 activates salicylic acid- and jasmonic acid-signaling pathways in rice plants and confers both antixenosis and antibiosis to BPH. We further demonstrated that the eight BPH-resistance genes that are clustered on chromosome 12L, including the widely used BPH1, are allelic with each other. To honor the priority in the literature, we thus designated this locus as BPH1/9 These eight genes can be classified into four allelotypes, BPH1/9-1, -2, -7, and -9 These allelotypes confer varying levels of resistance to different biotypes of BPH. The coding region of BPH1/9 shows a high level of diversity in rice germplasm. Homologous fragments of the nucleotide-binding (NB) and leucine-rich repeat (LRR) domains exist, which might have served as a repository for generating allele diversity. Our findings reveal a rice plant strategy for modifying the genetic information to gain the upper hand in the struggle against insect herbivores. Further exploration of natural allelic variation and artificial shuffling within this gene may allow breeding to be tailored to control emerging biotypes of BPH.

Genes located in a chromosomal inversion are correlated with territorial song in white-throated sparrows.

PubMed

Zinzow-Kramer, W M; Horton, B M; McKee, C D; Michaud, J M; Tharp, G K; Thomas, J W; Tuttle, E M; Yi, S; Maney, D L

2015-11-01

The genome of the white-throated sparrow (Zonotrichia albicollis) contains an inversion polymorphism on chromosome 2 that is linked to predictable variation in a suite of phenotypic traits including plumage color, aggression and parental behavior. Differences in gene expression between the two color morphs, which represent the two common inversion genotypes (ZAL2/ZAL2 and ZAL2/ZAL2(m) ), may therefore advance our understanding of the molecular underpinnings of these phenotypes. To identify genes that are differentially expressed between the two morphs and correlated with behavior, we quantified gene expression and terrirorial aggression, including song, in a population of free-living white-throated sparrows. We analyzed gene expression in two brain regions, the medial amygdala (MeA) and hypothalamus. Both regions are part of a 'social behavior network', which is rich in steroid hormone receptors and previously linked with territorial behavior. Using weighted gene co-expression network analyses, we identified modules of genes that were correlated with both morph and singing behavior. The majority of these genes were located within the inversion, showing the profound effect of the inversion on the expression of genes captured by the rearrangement. These modules were enriched with genes related to retinoic acid signaling and basic cellular functioning. In the MeA, the most prominent pathways were those related to steroid hormone receptor activity. Within these pathways, the only gene encoding such a receptor was ESR1 (estrogen receptor 1), a gene previously shown to predict song rate in this species. The set of candidate genes we identified may mediate the effects of a chromosomal inversion on territorial behavior. © 2015 John Wiley & Sons Ltd and International Behavioural and Neural Genetics Society.

Long range chromosome organization in Escherichia coli: The position of the replication origin defines the non-structured regions and the Right and Left macrodomains

PubMed Central

2017-01-01

The Escherichia coli chromosome is organized into four macrodomains (Ori, Ter, Right and Left) and two non-structured regions. This organization influences the segregation of sister chromatids, the mobility of chromosomal DNA, and the cellular localization of the chromosome. The organization of the Ter and Ori macrodomains relies on two specific systems, MatP/matS for the Ter domain and MaoP/maoS for the Ori domain, respectively. Here by constructing strains with chromosome rearrangements to reshuffle the distribution of chromosomal segments, we reveal that the difference between the non-structured regions and the Right and Left lateral macrodomains relies on their position on the chromosome. A change in the genetic location of oriC generated either by an inversion within the Ori macrodomain or by the insertion of a second oriC modifies the position of Right and Left macrodomains, as the chromosome region the closest to oriC are always non-structured while the regions further away behave as macrodomain regardless of their DNA sequence. Using fluorescent microscopy we estimated that loci belonging to a non-structured region are significantly closer to the Ori MD than loci belonging to a lateral MD. Altogether, our results suggest that the origin of replication plays a prominent role in chromosome organization in E. coli, as it determines structuring and localization of macrodomains in growing cell. PMID:28486476

The genetics of folate metabolism and maternal risk of birth of a child with Down syndrome and associated congenital heart defects

PubMed Central

Coppedè, Fabio

2015-01-01

Almost 15 years ago it was hypothesized that polymorphisms of genes encoding enzymes involved in folate metabolism could lead to aberrant methylation of peri-centromeric regions of chromosome 21, favoring its abnormal segregation during maternal meiosis. Subsequently, more than 50 small case-control studies investigated whether or not maternal polymorphisms of folate pathway genes could be risk factors for the birth of a child with Down syndrome (DS), yielding conflicting and inconclusive results. However, recent meta-analyses of those studies suggest that at least three of those polymorphisms, namely MTHFR 677C>T, MTRR 66A>G, and RFC1 80G>A, are likely to act as maternal risk factors for the birth of a child with trisomy 21, revealing also complex gene-nutrient interactions. A large-cohort study also revealed that lack of maternal folic acid supplementation at peri-conception resulted in increased risk for a DS birth due to errors occurred at maternal meiosis II in the aging oocyte, and it was shown that the methylation status of chromosome 21 peri-centromeric regions could favor recombination errors during meiosis leading to its malsegregation. In this regard, two recent case-control studies revealed association of maternal polymorphisms or haplotypes of the DNMT3B gene, coding for an enzyme required for the regulation of DNA methylation at centromeric and peri-centromeric regions of human chromosomes, with risk of having a birth with DS. Furthermore, congenital heart defects (CHD) are found in almost a half of DS births, and increasing evidence points to a possible contribution of lack of folic acid supplementation at peri-conception, maternal polymorphisms of folate pathway genes, and resulting epigenetic modifications of several genes, at the basis of their occurrence. This review summarizes available case-control studies and literature meta-analyses in order to provide a critical and up to date overview of what we currently know in this field. PMID:26161087

Evidence for chromosome 2p16.3 polycystic ovary syndrome susceptibility locus in affected women of European ancestry.

PubMed

Mutharasan, Priscilla; Galdones, Eugene; Peñalver Bernabé, Beatriz; Garcia, Obed A; Jafari, Nadereh; Shea, Lonnie D; Woodruff, Teresa K; Legro, Richard S; Dunaif, Andrea; Urbanek, Margrit

2013-01-01

A previous genome-wide association study in Chinese women with polycystic ovary syndrome (PCOS) identified a region on chromosome 2p16.3 encoding the LH/choriogonadotropin receptor (LHCGR) and FSH receptor (FSHR) genes as a reproducible PCOS susceptibility locus. The objective of the study was to determine the role of the LHCGR and/or FSHR gene in the etiology of PCOS in women of European ancestry. This was a genetic association study in a European ancestry cohort of women with PCOS. The study was conducted at an academic medical center. Participants in the study included 905 women with PCOS diagnosed by National Institutes of Health criteria and 956 control women. We genotyped 94 haplotype-tagging single-nucleotide polymorphisms and two coding single-nucleotide polymorphisms mapping to the coding region of LHCGR and FSHR plus 20 kb upstream and downstream of the genes and test for association in the case control cohort and for association with nine quantitative traits in the women with PCOS. We found strong evidence for an association of PCOS with rs7562215 (P = 0.0037) and rs10495960 (P = 0.0046). Although the marker with the strongest association in the Chinese PCOS genome-wide association study (rs13405728) was not informative in the European populations, we identified and genotyped three markers (rs35960650, rs2956355, and rs7562879) within 5 kb of rs13405728. Of these, rs7562879 was nominally associated with PCOS (P = 0.020). The strongest evidence for association mapping to FSHR was observed with rs1922476 (P = 0.0053). Furthermore, markers with the FSHR gene region were associated with FSH levels in women with PCOS. Fine mapping of the chromosome 2p16.3 Chinese PCOS susceptibility locus in a European ancestry cohort provides evidence for association with two independent loci and PCOS. The gene products LHCGR and FSHR therefore are likely to be important in the etiology of PCOS, regardless of ethnicity.

Fine mapping and identification of candidate genes for the sy-2 locus in a temperature-sensitive chili pepper (Capsicum chinense).

PubMed

Liu, Li; Venkatesh, Jelli; Jo, Yeong Deuk; Koeda, Sota; Hosokawa, Munetaka; Kang, Jin-Ho; Goritschnig, Sandra; Kang, Byoung-Cheorl

2016-08-01

The sy - 2 temperature-sensitive gene from Capsicum chinense was fine mapped to a 138.8-kb region at the distal portion of pepper chromosome 1. Based on expression analyses, two putative F-box genes were identified as sy - 2 candidate genes. Seychelles-2 ('sy-2') is a temperature-sensitive natural mutant of Capsicum chinense, which exhibits an abnormal leaf phenotype when grown at temperatures below 24 °C. We previously showed that the sy-2 phenotype is controlled by a single recessive gene, sy-2, located on pepper chromosome 1. In this study, a high-resolution genetic and physical map for the sy-2 locus was constructed using two individual F2 mapping populations derived from a cross between C. chinense mutant 'sy-2' and wild-type 'No. 3341'. The sy-2 gene was fine mapped to a 138.8-kb region between markers SNP 5-5 and SNP 3-8 at the distal portion of chromosome 1, based on comparative genomic analysis and genomic information from pepper. The sy-2 target region was predicted to contain 27 genes. Expression analysis of these predicted genes showed a differential expression pattern for ORF10 and ORF20 between mutant and wild-type plants; with both having significantly lower expression in 'sy-2' than in wild-type plants. In addition, the coding sequences of both ORF10 and ORF20 contained single nucleotide polymorphisms (SNPs) causing amino acid changes, which may have important functional consequences. ORF10 and ORF20 are predicted to encode F-box proteins, which are components of the SCF complex. Based on the differential expression pattern and the presence of nonsynonymous SNPs, we suggest that these two putative F-box genes are most likely responsible for the temperature-sensitive phenotypes in pepper. Further investigation of these genes may enable a better understanding of the molecular mechanisms of low temperature sensitivity in plants.

The sex-specific region of sex chromosomes in animals and plants.

PubMed

Gschwend, Andrea R; Weingartner, Laura A; Moore, Richard C; Ming, Ray

2012-01-01

Our understanding of the evolution of sex chromosomes has increased greatly in recent years due to a number of molecular evolutionary investigations in divergent sex chromosome systems, and these findings are reshaping theories of sex chromosome evolution. In particular, the dynamics of the sex-determining region (SDR) have been demonstrated by recent findings in ancient and incipient sex chromosomes. Radical changes in genomic structure and gene content in the male specific region of the Y chromosome between human and chimpanzee indicated rapid evolution in the past 6 million years, defying the notion that the pace of evolution in the SDR was fast at early stages but slowed down overtime. The chicken Z and the human X chromosomes appeared to have acquired testis-expressed genes and expanded in intergenic regions. Transposable elements greatly contributed to SDR expansion and aided the trafficking of genes in the SDR and its X or Z counterpart through retrotransposition. Dosage compensation is not a destined consequence of sex chromosomes as once thought. Most X-linked microRNA genes escape silencing and are expressed in testis. Collectively, these findings are challenging many of our preconceived ideas of the evolutionary trajectory and fates of sex chromosomes.

A Pol V–Mediated Silencing, Independent of RNA–Directed DNA Methylation, Applies to 5S rDNA

PubMed Central

Douet, Julien; Tutois, Sylvie; Tourmente, Sylvette

2009-01-01

The plant-specific RNA polymerases Pol IV and Pol V are essential to RNA–directed DNA methylation (RdDM), which also requires activities from RDR2 (RNA–Dependent RNA Polymerase 2), DCL3 (Dicer-Like 3), AGO4 (Argonaute), and DRM2 (Domains Rearranged Methyltransferase 2). RdDM is dedicated to the methylation of target sequences which include transposable elements, regulatory regions of several protein-coding genes, and 5S rRNA–encoding DNA (rDNA) arrays. In this paper, we have studied the expression of the 5S-210 transcript, a marker of silencing release at 5S RNA genes, to show a differential impact of RNA polymerases IV and V on 5S rDNA arrays during early development of the plant. Using a combination of molecular and cytological assays, we show that Pol IV, RDR2, DRM2, and Pol V, actors of the RdDM, are required to maintain a transcriptional silencing of 5S RNA genes at chromosomes 4 and 5. Moreover, we have shown a derepression associated to chromatin decondensation specific to the 5S array from chromosome 4 and restricted to the Pol V–loss of function. In conclusion, our results highlight a new role for Pol V on 5S rDNA, which is RdDM–independent and comes specifically at chromosome 4, in addition to the RdDM pathway. PMID:19834541

A 11.7-kb deletion triggers intersexuality and polledness in goats.

PubMed

Pailhoux, E; Vigier, B; Chaffaux, S; Servel, N; Taourit, S; Furet, J P; Fellous, M; Grosclaude, F; Cribiu, E P; Cotinot, C; Vaiman, D

2001-12-01

Mammalian sex determination is governed by the presence of the sex determining region Y gene (SRY) on the Y chromosome. Familial cases of SRY-negative XX sex reversal are rare in humans, often hampering the discovery of new sex-determining genes. The mouse model is also insufficient to correctly apprehend the sex-determination cascade, as the human pathway is much more sensitive to gene dosage. Other species might therefore be considered in this respect. In goats, the polled intersex syndrome (PIS) mutation associates polledness and intersexuality. The sex reversal affects exclusively the XX individuals in a recessive manner, whereas the absence of horns is dominant in both sexes. The syndrome is caused by an autosomal gene located at chromosome band 1q43 (ref. 9), shown to be homologous to human chromosome band 3q23 (ref. 10). Through a positional cloning approach, we demonstrate that the mutation underlying PIS is the deletion of a critical 11.7-kb DNA element containing mainly repetitive sequences. This deletion affects the transcription of at least two genes: PISRT1, encoding a 1.5-kb mRNA devoid of open reading frame (ORF), and FOXL2, recently shown to be responsible for blepharophimosis ptosis epicanthus inversus syndrome (BPES) in humans. These two genes are located 20 and 200 kb telomeric from the deletion, respectively.

Erratum: Letter to the Editor: Exclusion of primary congenital glaucoma (buphthalmos) from two candidate regions of chromosome arm 6p and chromosome 11

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

NONE

1996-03-01

This {open_quotes}Letter to the Editor{close_quotes} is the reprint of a corrected table from a previous paper about the exclusion of primary congenital glaucoma from two candidate regions of chromosome arm 6p and chromosome 11.

FISH with whole chromosome and telomeric probes demonstrates huge karyotypic reorganization with ITS between two species of Oryzomyini (Sigmodontinae, Rodentia): Hylaeamys megacephalus probes on Cerradomys langguthi karyotype.

PubMed

Nagamachi, Cleusa Yoshiko; Pieczarka, Julio Cesar; O'Brien, Patricia Caroline Mary; Pinto, Jamilly Amaral; Malcher, Stella Miranda; Pereira, Adenilson Leão; Rissino, Jorge das Dores; Mendes-Oliveira, Ana Cristina; Rossi, Rogério Vieira; Ferguson-Smith, Malcolm Andrew

2013-04-01

Rodentia comprises 42 % of living mammalian species. The taxonomic identification can be difficult, the number of species currently known probably being underestimated, since many species show only slight morphological variations. Few studies surveyed the biodiversity of species, especially in the Amazon region. Cytogenetic studies show great chromosomal variability in rodents, with diploid numbers ranging from 10 to 102, making it difficult to find chromosomal homologies by comparative G banding. Chromosome painting is useful, but only a few species of rodents have been studied by this technique. In this study, we sorted whole chromosome probes by fluorescence-activated cell sorting from two Hylaeamys megacephalus individuals, an adult female (2n = 54) and a fetus (2n = 50). We made reciprocal chromosome painting between these karyotypes and cross-species hybridization on Cerradomys langguthi (2n = 46). Both species belong to the tribe Oryzomyini (Sigmodontinae), which is restricted to South America and were collected in the Amazon region. Twenty-four chromosome-specific probes from the female and 25 from the fetus were sorted. Reciprocal chromosome painting shows that the karyotype of the fetus does not represent a new cytotype, but an unbalanced karyotype with multiple rearrangements. Cross-species hybridization of H. megacephalus probes on metaphases of C. langguthi shows that 11 chromosomes of H. megacephalus revealed conserved synteny, 10 H. megacephalus probes hybridized to two chromosomal regions and three hybridized to three regions. Associations were observed on chromosomes pairs 1-4 and 11. Fluorescence in situ hybridization with a telomeric probe revealed interstitial regions in three pairs (1, 3, and 4) of C. langguthi chromosomes. We discuss the genomic reorganization of the C. langguthi karyotype.

Sex Chromosome Turnover Contributes to Genomic Divergence between Incipient Stickleback Species

PubMed Central

Yoshida, Kohta; Makino, Takashi; Yamaguchi, Katsushi; Shigenobu, Shuji; Hasebe, Mitsuyasu; Kawata, Masakado; Kume, Manabu; Mori, Seiichi; Peichel, Catherine L.; Toyoda, Atsushi; Fujiyama, Asao; Kitano, Jun

2014-01-01

Sex chromosomes turn over rapidly in some taxonomic groups, where closely related species have different sex chromosomes. Although there are many examples of sex chromosome turnover, we know little about the functional roles of sex chromosome turnover in phenotypic diversification and genomic evolution. The sympatric pair of Japanese threespine stickleback (Gasterosteus aculeatus) provides an excellent system to address these questions: the Japan Sea species has a neo-sex chromosome system resulting from a fusion between an ancestral Y chromosome and an autosome, while the sympatric Pacific Ocean species has a simple XY sex chromosome system. Furthermore, previous quantitative trait locus (QTL) mapping demonstrated that the Japan Sea neo-X chromosome contributes to phenotypic divergence and reproductive isolation between these sympatric species. To investigate the genomic basis for the accumulation of genes important for speciation on the neo-X chromosome, we conducted whole genome sequencing of males and females of both the Japan Sea and the Pacific Ocean species. No substantial degeneration has yet occurred on the neo-Y chromosome, but the nucleotide sequence of the neo-X and the neo-Y has started to diverge, particularly at regions near the fusion. The neo-sex chromosomes also harbor an excess of genes with sex-biased expression. Furthermore, genes on the neo-X chromosome showed higher non-synonymous substitution rates than autosomal genes in the Japan Sea lineage. Genomic regions of higher sequence divergence between species, genes with divergent expression between species, and QTL for inter-species phenotypic differences were found not only at the regions near the fusion site, but also at other regions along the neo-X chromosome. Neo-sex chromosomes can therefore accumulate substitutions causing species differences even in the absence of substantial neo-Y degeneration. PMID:24625862

Detection of amplified or deleted chromosomal regions

DOEpatents

Stokke, Trond; Pinkel, Daniel; Gray, Joe W.

1995-01-01

The present invention relates to in situ hybridization methods for the identification of new chromosomal abnormalities associated with various diseases. In particular, it provides probes which are specific to a region of amplification in chromosome 20.

Detection Of Amplified Or Deleted Chromosomal Regions

DOEpatents

Stokke, Trond , Pinkel, Daniel , Gray, Joe W.

1997-05-27

The present invention relates to in situ hybridization methods for the identification of new chromosomal abnormalities associated with various diseases. In particular, it provides probes which are specific to a region of amplification in chromosome 20.

The Y-located gonadoblastoma gene TSPY amplifies its own expression through a positive feedback loop in prostate cancer cells

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

Kido, Tatsuo; Lau, Yun-Fai Chris, E-mail: Chris.Lau@UCSF.edu

2014-03-28

Highlights: • Y-encoded proto-oncoprotein TSPY amplifies its expression level via a positive feedback loop. • TSPY binds to the chromatin/DNA at exon 1 of TSPY gene. • TSPY enhances the gene expression in a TSPY exon 1 sequence dependent manner. • The conserved SET/NAP-domain is essential for TSPY transactivation. • Insights on probable mechanisms on TSPY exacerbation on cancer development in men. - Abstract: The testis-specific protein Y-encoded (TSPY) is a repetitive gene located on the gonadoblastoma region of the Y chromosome, and has been considered to be the putative gene for this oncogenic locus on the male-only chromosome. Itmore » is expressed in spermatogonial cells and spermatocytes in normal human testis, but abundantly in gonadoblastoma, testicular germ cell tumors and a variety of somatic cancers, including melanoma, hepatocellular carcinoma and prostate cancer. Various studies suggest that TSPY accelerates cell proliferation and growth, and promotes tumorigenesis. In this report, we show that TSPY could bind directly to the chromatin/DNA at exon 1 of its own gene, and greatly enhance the transcriptional activities of the endogenous gene in the LNCaP prostate cancer cells. Domain mapping analyses of TSPY have localized the critical and sufficient domain to the SET/NAP-domain. These results suggest that TSPY could efficiently amplify its expression and oncogenic functions through a positive feedback loop, and contribute to the overall tumorigenic processes when it is expressed in various human cancers.« less

Multilocus analysis of extracellular putative virulence proteins made by group A Streptococcus: population genetics, human serologic response, and gene transcription.

PubMed

Reid, S D; Green, N M; Buss, J K; Lei, B; Musser, J M

2001-06-19

Species of pathogenic microbes are composed of an array of evolutionarily distinct chromosomal genotypes characterized by diversity in gene content and sequence (allelic variation). The occurrence of substantial genetic diversity has hindered progress in developing a comprehensive understanding of the molecular basis of virulence and new therapeutics such as vaccines. To provide new information that bears on these issues, 11 genes encoding extracellular proteins in the human bacterial pathogen group A Streptococcus identified by analysis of four genomes were studied. Eight of the 11 genes encode proteins with a LPXTG(L) motif that covalently links Gram-positive virulence factors to the bacterial cell surface. Sequence analysis of the 11 genes in 37 geographically and phylogenetically diverse group A Streptococcus strains cultured from patients with different infection types found that recent horizontal gene transfer has contributed substantially to chromosomal diversity. Regions of the inferred proteins likely to interact with the host were identified by molecular population genetic analysis, and Western immunoblot analysis with sera from infected patients confirmed that they were antigenic. Real-time reverse transcriptase-PCR (TaqMan) assays found that transcription of six of the 11 genes was substantially up-regulated in the stationary phase. In addition, transcription of many genes was influenced by the covR and mga trans-acting gene regulatory loci. Multilocus investigation of putative virulence genes by the integrated approach described herein provides an important strategy to aid microbial pathogenesis research and rapidly identify new targets for therapeutics research.

Germline genetics of cancer of unknown primary (CUP) and its specific subtypes.

PubMed

Hemminki, Kari; Chen, Bowang; Kumar, Abhishek; Melander, Olle; Manjer, Jonas; Hallmans, Göran; Pettersson-Kymmer, Ulrika; Ohlsson, Claes; Folprecht, Gunnar; Löffler, Harald; Krämer, Alwin; Försti, Asta

2016-04-19

Cancer of unknown primary site (CUP) is a fatal cancer diagnosed through metastases at various organs. Little is known about germline genetics of CUP which appears worth of a search in view of reported familial associations in CUP. In the present study, samples from CUP patients were identified from 2 Swedish biobanks and a German clinical trial, totaling 578 CUP patients and 7628 regionally matched controls. Diagnostic data specified the organ where metastases were diagnosed. We carried out a genome-wide association study on CUP cases and controls. In the whole sample set, 6 loci reached an allelic p-value in the range of 10-7 and were supported by data from the three centers. Three associations were located next to non-coding RNA genes. rs2660852 flanked 5'UTR of LTA4H (leukotriene A4 hydrolase), rs477145 was intronic to TIAM1 (T-cell lymphoma invasion and metastases) and rs2835931 was intronic to KCNJ6 (potassium channel, inwardly rectifying subfamily J, member 6). In analysis of subgroups of CUP patients (smokers, non-smokers and CUP with liver metastases) genome-wide significant associations were noted. For patients with liver metastases associations on chromosome 6 and 11, the latter including a cluster of genes DHCR7 and NADSYN1, encoding key enzymes in cholesterol and NAD synthesis, and KRTAP5-7, encoding a keratin associated protein. This first GWAS on CUP provide preliminary evidence that germline genes relating to inflammation (LTA4H), metastatic promotion (TIAM1) in association with lipid metabolic disturbance (chromosome 11 cluster) may contribute to the risk of CUP.

Differential conservation of transcriptional domains of mammalian Prophet of Pit-1 proteins revealed by structural studies of the bovine gene and comparative functional analysis of the protein.

PubMed

Showalter, Aaron D; Smith, Timothy P L; Bennett, Gary L; Sloop, Kyle W; Whitsett, Julie A; Rhodes, Simon J

2002-05-29

The Prophet of Pit-1 (PROP1) gene encodes a paired class homeodomain transcription factor that is exclusively expressed in the developing mammalian pituitary gland. PROP1 function is essential for anterior pituitary organogenesis, and heritable mutations in the gene are associated with combined pituitary hormone deficiency in human patients and animals. By cloning the bovine PROP1 gene and by comparative analysis, we demonstrate that the homeodomains and carboxyl termini of mammalian PROP1 proteins are highly conserved while the amino termini are diverged. Whereas the carboxyl termini of the human and bovine PROP1 proteins contain potent transcriptional activation domains, the amino termini and homeodomains have repressive activities. The bovine PROP1 gene has four exons and three introns and maps to a region of chromosome seven carrying a quantitative trait locus affecting ovulation rate. Two alleles of the bovine gene were found that encode distinct protein products with different DNA binding and transcriptional activities. These experiments demonstrate that mammalian PROP1 genes encode proteins with complex regulatory capacities and that modest changes in protein sequence can significantly alter the activity of this pituitary developmental transcription factor.

Fragile Sites of ‘Valencia’ Sweet Orange (Citrus sinensis) Chromosomes Are Related with Active 45s rDNA

PubMed Central

Lan, Hong; Chen, Chun-Li; Miao, Yin; Yu, Chang-Xiu; Guo, Wen-Wu; Xu, Qiang; Deng, Xiu-Xin

2016-01-01

Citrus sinensis chromosomes present a morphological differentiation of bands after staining by the fluorochromes CMA and DAPI, but there is still little information on its chromosomal characteristics. In this study, the chromosomes in ‘Valencia’ C. sinensis were analyzed by fluorescence in situ hybridization (FISH) using telomere DNA and the 45S rDNA gene as probes combining CMA/DAPI staining, which showed that there were two fragile sites in sweet orange chromosomes co-localizing at distended 45S rDNA regions, one proximally locating on B-type chromosome and the other subterminally locating on D-type chromosome. While the chromosomal CMA banding and 45S rDNA FISH mapping in the doubled haploid line of ‘Valencia’ C. sinensis indicated six 45S rDNA regions, four were identified as fragile sites as doubled comparing its parental line, which confirmed the cytological heterozygosity and chromosomal heteromorphisms in sweet orange. Furthermore, Ag-NOR identified two distended 45S rDNA regions to be active nucleolar organizing regions (NORs) in diploid ‘Valencia’ C. sinensis. The occurrence of quadrivalent in meiosis of pollen mother cells (PMCs) in ‘Valencia’ sweet orange further confirmed it was a chromosomal reciprocal translocation line. We speculated this chromosome translocation was probably related to fragile sites. Our data provide insights into the chromosomal characteristics of the fragile sites in ‘Valencia’ sweet orange and are expected to facilitate the further investigation of the possible functions of fragile sites. PMID:26977938

Fragile Sites of 'Valencia' Sweet Orange (Citrus sinensis) Chromosomes Are Related with Active 45s rDNA.

PubMed

Lan, Hong; Chen, Chun-Li; Miao, Yin; Yu, Chang-Xiu; Guo, Wen-Wu; Xu, Qiang; Deng, Xiu-Xin

2016-01-01

Citrus sinensis chromosomes present a morphological differentiation of bands after staining by the fluorochromes CMA and DAPI, but there is still little information on its chromosomal characteristics. In this study, the chromosomes in 'Valencia' C. sinensis were analyzed by fluorescence in situ hybridization (FISH) using telomere DNA and the 45S rDNA gene as probes combining CMA/DAPI staining, which showed that there were two fragile sites in sweet orange chromosomes co-localizing at distended 45S rDNA regions, one proximally locating on B-type chromosome and the other subterminally locating on D-type chromosome. While the chromosomal CMA banding and 45S rDNA FISH mapping in the doubled haploid line of 'Valencia' C. sinensis indicated six 45S rDNA regions, four were identified as fragile sites as doubled comparing its parental line, which confirmed the cytological heterozygosity and chromosomal heteromorphisms in sweet orange. Furthermore, Ag-NOR identified two distended 45S rDNA regions to be active nucleolar organizing regions (NORs) in diploid 'Valencia' C. sinensis. The occurrence of quadrivalent in meiosis of pollen mother cells (PMCs) in 'Valencia' sweet orange further confirmed it was a chromosomal reciprocal translocation line. We speculated this chromosome translocation was probably related to fragile sites. Our data provide insights into the chromosomal characteristics of the fragile sites in 'Valencia' sweet orange and are expected to facilitate the further investigation of the possible functions of fragile sites.

Characterisation of the subtelomeric regions of Giardia lamblia genome isolate WBC6.

PubMed

Prabhu, Anjali; Morrison, Hilary G; Martinez, Charles R; Adam, Rodney D

2007-04-01

Giardia trophozoites are polyploid and have five chromosomes. The chromosome homologues demonstrate considerable size heterogeneity due to variation in the subtelomeric regions. We used clones from the genome project with telomeric sequence at one end to identify six subtelomeric regions in addition to previously identified subtelomeric regions, to study the telomeric arrangement of the chromosomes. The subtelomeric regions included two retroposons, one retroposon pseudogene, and two vsp genes, in addition to the previously identified subtelomeric regions that include ribosomal DNA repeats. The presence of vsp genes in a subtelomeric region suggests that telomeric rearrangements may contribute to the generation of vsp diversity. These studies of the subtelomeric regions of Giardia may contribute to our understanding of the factors that maintain stability, while allowing diversity in chromosome structure.

Repetitive sequences and epigenetic modification: inseparable partners play important roles in the evolution of plant sex chromosomes.

PubMed

Li, Shu-Fen; Zhang, Guo-Jun; Yuan, Jin-Hong; Deng, Chuan-Liang; Gao, Wu-Jun

2016-05-01

The present review discusses the roles of repetitive sequences played in plant sex chromosome evolution, and highlights epigenetic modification as potential mechanism of repetitive sequences involved in sex chromosome evolution. Sex determination in plants is mostly based on sex chromosomes. Classic theory proposes that sex chromosomes evolve from a specific pair of autosomes with emergence of a sex-determining gene(s). Subsequently, the newly formed sex chromosomes stop recombination in a small region around the sex-determining locus, and over time, the non-recombining region expands to almost all parts of the sex chromosomes. Accumulation of repetitive sequences, mostly transposable elements and tandem repeats, is a conspicuous feature of the non-recombining region of the Y chromosome, even in primitive one. Repetitive sequences may play multiple roles in sex chromosome evolution, such as triggering heterochromatization and causing recombination suppression, leading to structural and morphological differentiation of sex chromosomes, and promoting Y chromosome degeneration and X chromosome dosage compensation. In this article, we review the current status of this field, and based on preliminary evidence, we posit that repetitive sequences are involved in sex chromosome evolution probably via epigenetic modification, such as DNA and histone methylation, with small interfering RNAs as the mediator.

Human AZU-1 gene, variants thereof and expressed gene products

DOEpatents

Chen, Huei-Mei; Bissell, Mina

2004-06-22

A human AZU-1 gene, mutants, variants and fragments thereof. Protein products encoded by the AZU-1 gene and homologs encoded by the variants of AZU-1 gene acting as tumor suppressors or markers of malignancy progression and tumorigenicity reversion. Identification, isolation and characterization of AZU-1 and AZU-2 genes localized to a tumor suppressive locus at chromosome 10q26, highly expressed in nonmalignant and premalignant cells derived from a human breast tumor progression model. A recombinant full length protein sequences encoded by the AZU-1 gene and nucleotide sequences of AZU-1 and AZU-2 genes and variant and fragments thereof. Monoclonal or polyclonal antibodies specific to AZU-1, AZU-2 encoded protein and to AZU-1, or AZU-2 encoded protein homologs.

IN SITU DEMONSTRATION OF DNA HYBRIDIZING WITH CHROMOSOMAL AND NUCLEAR SAP RNA IN CHIRONOMUS TENTANS

PubMed Central

Lambert, B.; Wieslander, L.; Daneholt, B.; Egyházi, E.; Ringborg, U.

1972-01-01

Cytological hybridization combined with microdissection of Chironomus tentans salivary gland cells was used to locate DNA complementary to newly synthesized RNA from chromosomes and nuclear sap and from a single chromosomal puff, the Balbiani ring 2 (BR 2). Salivary glands were incubated with tritiated nucleosides. The labeled RNA was extracted from microdissected nuclei and hybridized to denatured squash preparations of salivary gland cells under conditions which primarily allow repeated sequences to interact. The bound RNA, resistant to ribonuclease treatment, was detected radioautographically. It was found that BR 2 RNA hybridizes specifically with the BR 2 region of chromosome IV. Nuclear sap RNA was fractionated into high and low molecular-weight RNA; the former hybridizes with the BR 2 region of chromosome IV, the latter in a diffuse distribution over the whole chromosome set. RNA from chromosome I hybridizes diffusely with all chromosomes. Nucleolar RNA hybridizes specifically with the nucleolar organizers, contained in chromosomes II and III. It is concluded that the BR 2 region of chromosome IV contains repeated DNA sequences and that nuclear sap contains BR 2 RNA. PMID:5025107

Recent Sex Chromosome Divergence despite Ancient Dioecy in the Willow Salix viminalis.

PubMed

Pucholt, Pascal; Wright, Alison E; Conze, Lei Liu; Mank, Judith E; Berlin, Sofia

2017-08-01

Sex chromosomes can evolve when recombination is halted between a pair of chromosomes, and this can lead to degeneration of the sex-limited chromosome. In the early stages of differentiation sex chromosomes are homomorphic, and even though homomorphic sex chromosomes are very common throughout animals and plants, we know little about the evolutionary forces shaping these types of sex chromosomes. We used DNA- and RNA-Seq data from females and males to explore the sex chromosomes in the female heterogametic willow, Salix viminalis, a species with ancient dioecy but with homomorphic sex chromosomes. We detected no major sex differences in read coverage in the sex determination (SD) region, indicating that the W region has not significantly degenerated. However, single nucleotide polymorphism densities in the SD region are higher in females compared with males, indicating very recent recombination suppression, followed by the accumulation of sex-specific single nucleotide polymorphisms. Interestingly, we identified two female-specific scaffolds that likely represent W-chromosome-specific sequence. We show that genes located in the SD region display a mild excess of male-biased expression in sex-specific tissue, and we use allele-specific gene expression analysis to show that this is the result of masculinization of expression on the Z chromosome rather than degeneration of female-expression on the W chromosome. Together, our results demonstrate that insertion of small DNA fragments and accumulation of sex-biased gene expression can occur before the detectable decay of the sex-limited chromosome. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

[Chromosomal variation in Chironomus plumosus L. (Diptera, Chironomidae) from populations of Bryansk region, Saratov region (Russia), and Gomel region (Belarus)].

PubMed

Belyanina, S I

2015-02-01

Cytogenetic analysis was performed on samples of Chironomus plumosus L. (Diptera, Chironomidae) taken from waterbodies of various types in Bryansk region (Russia) and Gomel region (Belarus). Karyotypes of specimens taken from stream pools of the Volga were used as reference samples. The populations of Bryansk and Gomel regions (except for a population of Lake Strativa in Starodubskii district, Bryansk region) exhibit broad structural variation, including somatic mosaicism for morphotypes of the salivary gland chromosome set, decondensation of telomeric sites, and the presence of small structural changes, as opposed to populations of Saratov region. As compared with Saratov and Bryansk regions, the Balbiani ring in the B-arm of chromosome I is repressed in populations of Gomel region. It is concluded that the chromosome set of Ch. plumosus in a range of waterbodies of Bryansk and Gomel regions is unstable.

Cytogenetic studies in Eigenmannia virescens (Sternopygidae, Gymnotiformes) and new inferences on the origin of sex chromosomes in the Eigenmannia genus

PubMed Central

2009-01-01

Background Cytogenetic studies were carried out on samples of Eigenmannia virescens (Sternopygidae, Gymnotiformes) obtained from four river systems of the Eastern Amazon region (Para, Brazil). Results All four populations had 2n = 38, with ZZ/ZW sex chromosomes (Z, acrocentric; W, submetacentric). Constitutive heterochromatin (CH) was found at the centromeric regions of all chromosomes. The W chromosome had a heterochromatic block in the proximal region of the short arm; this CH was positive for DAPI staining, indicating that it is rich in A-T base pairs. The nucleolar organizer region (NOR) was localized to the short arm of chromosome pair 15; this result was confirmed by fluorescent in situ hybridization (FISH) with human 45S rDNA, and CMA3 staining indicated that the region is G-C rich. FISH with telomeric probes did not show any evidence of interstitial telomeric sequences (ITS). Conclusion Previous studies have shown that the species Eigenmannia sp. 2 and E. virescens have differentiated sex chromosomes, and diverse sex chromosome systems have been described for E. virescens specimens obtained from different Brazilian rivers. A comparative analysis of the present data and prior reports suggests that the sex chromosomes of Eigenmannia may have arisen independently in the different populations. PMID:19930594

Neomycin resistance as a selectable marker in Methanococcus maripaludis

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

Argyle, J.L.; Leigh, J.A.; Tumbula, D.L.

1996-11-01

The authors cloned the aminoglycoside phosphotransferase genes APH3{prime}I and APH3{prime}II between the Methanococcus voltae methyl reductase promoter and terminator in a plasmid containing a fragment of Methanococcus maripaludis chromosomal DNA. The resulting plasmids encoding neomycin resistance transformed M. maripaludis at frequencies similar to those observed for pKAS102 encoding puromycin resistance. The antibiotic geneticin was not inhibitory to M. maripaludis. 22 refs., 3 figs., 3 tabs.

Recombinant plasmids for encoding restriction enzymes DpnI and DpnII of streptococcus pneumontae

DOEpatents

Lacks, Sanford A.

1990-01-01

Chromosomal DNA cassettes containing genes encoding either the DpnI or DpnII restriction endonucleases from Streptococcus pneumoniae are cloned into a streptococcal vector, pLS101. Large amounts of the restriction enzymes are produced by cells containing the multicopy plasmids, pLS202 and pLS207, and their derivatives pLS201, pLS211, pLS217, pLS251 and pLS252.

Recombinant plasmids for encoding restriction enzymes DpnI and DpnII of Streptococcus pneumontae

DOEpatents

Lacks, S.A.

1990-10-02

Chromosomal DNA cassettes containing genes encoding either the DpnI or DpnII restriction endonucleases from Streptococcus pneumoniae are cloned into a streptococcal vector, pLS101. Large amounts of the restriction enzymes are produced by cells containing the multicopy plasmids, pLS202 and pLS207, and their derivatives pLS201, pLS211, pLS217, pLS251 and pLS252. 9 figs.

X-derived marker chromosome in patient with mosaic Turner syndrome and Dandy-Walker syndrome: a case report.

PubMed

Telepova, Alena S; Romanenko, Svetlana A; Lemskaya, Natalya A; Maksimova, Yulia V; Shorina, Asia R; Yudkin, Dmitry V

2017-01-01

Small supernumerary marker chromosomes can be derived from autosomes and sex chromosomes and can accompany chromosome pathologies, such as Turner syndrome. Here, we present a case report of a patient with mosaic Turner syndrome and Dandy-Walker syndrome carrying a marker chromosome. We showed the presence of the marker chromosome in 33.8% of blood cells. FISH of the probe derived from the marker chromosome by microdissection revealed that it originated from the centromeric region of chromosome X. Additionally, we showed no telomeric sequences and no XIST sequence in the marker chromosome. This is the first report of these two syndromes accompanied by the presence of a marker chromosome. Marker chromosome was X-derived and originated from centromeric region. Patient has mild symptoms but there is no XIST gene in marker chromosome. CPG137. Registered 03 March 2017.

Detection of amplified or deleted chromosomal regions

DOEpatents

Stokke, T.; Pinkel, D.; Gray, J.W.

1995-12-05

The present invention relates to in situ hybridization methods for the identification of new chromosomal abnormalities associated with various diseases. In particular, it provides probes which are specific to a region of amplification in chromosome 20. 3 figs.

Similarities in the chromosomal distribution of AG and AC repeats within and between Drosophila, human and barley chromosomes.

PubMed

Cuadrado, A; Jouve, N

2007-01-01

Two simple sequence repeats (SSRs), AG and AC, were mapped directly in the metaphase chromosomes of man and barley (Hordeum vulgare L.), and in the metaphase and polytene chromosomes of Drosophila melanogaster. To this end, synthetic oligonucleotides corresponding to (AG)(12) and (AC)(8) were labelled by the random primer technique and used as probes in fluorescent in situ hybridisation (FISH) under high stringency and strict washing conditions. The distribution and intensity of the signals for the repeat sequences were found to be characteristic of the chromosomes and genomes of the three species analysed. The AC repeat sites were uniformly dispersed along the euchromatic segments of all three genomes; in fact, they were largely excluded from the heterochromatin. The Drosophila genome showed a high density of AC sequences on the X chromosome in both mitotic and polytene nuclei. In contrast, the AG repeats were associated with the euchromatic regions of the polytene chromosomes (and in high density on the X chromosome), but were only seen in specific heterochromatic regions in the mitotic chromosomes of all three species. In Drosophila, the AG repeats were exclusively distributed on the tips of the Y chromosome and near the centromere on both arms of chromosome 2. In barley and man, AG repeats were associated with the centromeres (of all chromosomes) and nucleolar organizer regions, respectively. The conserved chromosome distribution of AC within and between these three phylogenetically distant species, and the association of AG in specific chromosome regions with structural or functional properties, suggests that long clusters of these repeats may have some, as yet unknown, role. Copyright (c) 2007 S. Karger AG, Basel.

B chromosomes are associated with redistribution of genetic recombination towards lower recombination chromosomal regions in perennial ryegrass.

PubMed

Harper, John; Phillips, Dylan; Thomas, Ann; Gasior, Dagmara; Evans, Caron; Powell, Wayne; King, Julie; King, Ian; Jenkins, Glyn; Armstead, Ian

2018-04-09

Supernumerary 'B' chromosomes are non-essential components of the genome present in a range of plant and animal species-including many grasses. Within diploid and polyploid ryegrass and fescue species, including the forage grass perennial ryegrass (Lolium perenne L.), the presence of B chromosomes has been reported as influencing both chromosome pairing and chiasma frequencies. In this study, the effects of the presence/absence of B chromosomes on genetic recombination has been investigated through generating DArT (Diversity Arrays Technology) marker genetic maps for six perennial ryegrass diploid populations, the pollen parents of which contained either two B or zero B chromosomes. Through genetic and cytological analyses of these progeny and their parents, we have identified that, while overall cytological estimates of chiasma frequencies were significantly lower in pollen mother cells with two B chromosomes as compared with zero B chromosomes, the recombination frequencies within some marker intervals were actually increased, particularly for marker intervals in lower recombination regions of chromosomes, namely pericentromeric regions. Thus, in perennial ryegrass, the presence of two B chromosomes redistributed patterns of meiotic recombination in pollen mother cells in ways which could increase the range of allelic variation available to plant breeders.

Anhidrotic ectodermal dysplasia gene region cloned in yeast artificial chromosomes

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

Kere, J.; Grzeschik, K.H.; Limon, J.

1993-05-01

Anhidrotic ectodermal dysplasia (EDA), an X-chromosomal recessive disorder, is expressed in a few females with chromosomal translocations involving bands Xq12-q13. Using available DNA markers from the region and somatic cell hybrids the authors mapped the X-chromosomal breakpoints in two such translocations. The breakpoints were further mapped within a yeast artificial chromosome contig constructed by chromosome walking techniques. Genomic DNA markers that map between the two translocation breakpoints were recovered representing putative portions of the EDA gene. 32 refs., 3 figs., 1 tab.

[High-resolution GTG-banding and nucleolar organizer regions of chromosomes of two vole species: Microtus rossiaemeridonionalis and M. transcaspicus (Rodentia, Arvicolidae)].

PubMed

Mazurok, N A; Rubtsova, N V; Isaenko, A A; Nesterova, T B; Meĭer, M N; Zakiian, S M

1998-08-01

With the use of the GTG-banding of prometaphase chromosomes, 503 and 402 segments were revealed in haploid chromosome sets of voles Microtus rossiaemeridionalis and M. transcaspicus, respectively. Based on a detailed study of chromosomes at different condensation levels, idiograms of M. rossiaemeridionalis and M. transcaspicus chromosomes were constructed. Sequential Ag-staining and GTG-banding allowed nucleolar organizer regions (NORs) to be localized in 16 and 11 chromosome pairs of M. rossiaemeridionalis and M. transcaspicus, respectively.

The gene for human U2 snRNP auxiliary factor small 35-kDa subunit (U2AF1) maps to the progressive myoclonus epilepsy (EPM1) critical region on chromosome 21q22.3

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

Lalioti, M.D.; Rossier, C.; Antonarakis, S.E.

1996-04-15

We used targeted exon trapping to clone portions of genes from human chromosome 21q22.3. One trapped sequence showed complete homology with the cDNA of human U2AF{sup 35} (M96982; HGM-approved nomenclature U2AF1), which encodes for the small 35-kDa subunit of the U2 snRNP auxiliary factor. Using the U2AF1 cDNA as a probe, we mapped this gene to cosmid Q15D2, a P1, and YAC 350F7 of the Chumakov et al. contig, close to the cystathionine-{beta}-synthase gene (CBS) on 21q22.3. This localization was confirmed by PCR using oligonucleotides from the 3{prime} UTR and by FISH. As U2AF1 associated with a number of differentmore » factors during mRNA splicing, overexpression in trisomy 21 individuals could contribute to some Down syndrome phenotypes by interfering with the splicing process. Furthermore, because this gene maps in the critical region for the progressive myoclonus epilepsy I locus (EPM1), mutation analysis will be carried out in patients to evaluate the potential role of U2AF1 as a candidate for EPM1. 24 refs., 1 fig.« less

oriTfinder: a web-based tool for the identification of origin of transfers in DNA sequences of bacterial mobile genetic elements.

PubMed

Li, Xiaobin; Xie, Yingzhou; Liu, Meng; Tai, Cui; Sun, Jingyong; Deng, Zixin; Ou, Hong-Yu

2018-05-04

oriTfinder is a web server that facilitates the rapid identification of the origin of transfer site (oriT) of a conjugative plasmid or chromosome-borne integrative and conjugative element. The utilized back-end database oriTDB was built upon more than one thousand known oriT regions of bacterial mobile genetic elements (MGEs) as well as the known MGE-encoding relaxases and type IV coupling proteins (T4CP). With a combination of similarity searches for the oriTDB-archived oriT nucleotide sequences and the co-localization of the flanking relaxase homologous genes, the oriTfinder can predict the oriT region with high accuracy in the DNA sequence of a bacterial plasmid or chromosome in minutes. The server also detects the other transfer-related modules, including the potential relaxase gene, T4CP gene and the type IV secretion system gene cluster, and the putative genes coding for virulence factors and acquired antibiotic resistance determinants. oriTfinder may contribute to meeting the increasing demands of re-annotations for bacterial conjugative, mobilizable or non-transferable elements and aid in the rapid risk accession of disease-relevant trait dissemination in pathogenic bacteria of interest. oriTfinder is freely available to all users without any login requirement at http://bioinfo-mml.sjtu.edu.cn/oriTfinder.

Global genetic architecture of an erythroid quantitative trait locus, HMIP-2.

PubMed

Menzel, Stephan; Rooks, Helen; Zelenika, Diana; Mtatiro, Siana N; Gnanakulasekaran, Akshala; Drasar, Emma; Cox, Sharon; Liu, Li; Masood, Mariam; Silver, Nicholas; Garner, Chad; Vasavda, Nisha; Howard, Jo; Makani, Julie; Adekile, Adekunle; Pace, Betty; Spector, Tim; Farrall, Martin; Lathrop, Mark; Thein, Swee Lay

2014-11-01

HMIP-2 is a human quantitative trait locus affecting peripheral numbers, size and hemoglobin composition of red blood cells, with a marked effect on the persistence of the fetal form of hemoglobin, HbF, in adults. The locus consists of multiple common variants in an enhancer region for MYB (chr 6q23.3), which encodes the hematopoietic transcription factor cMYB. Studying a European population cohort and four African-descended groups of patients with sickle cell anemia, we found that all share a set of two spatially separate HbF-promoting alleles at HMIP-2, termed "A" and "B." These typically occurred together ("A-B") on European chromosomes, but existed on separate homologous chromosomes in Africans. Using haplotype signatures for "A" and "B," we interrogated public population datasets. Haplotypes carrying only "A" or "B" were typical for populations in Sub-Saharan Africa. The "A-B" combination was frequent in European, Asian, and Amerindian populations. Both alleles were infrequent in tropical regions, possibly undergoing negative selection by geographical factors, as has been reported for malaria with other hematological traits. We propose that the ascertainment of worldwide distribution patterns for common, HbF-promoting alleles can aid their further genetic characterization, including the investigation of gene-environment interaction during human migration and adaptation. © 2014 The Authors. Annals of Human Genetics published by University College London (UCL) and John Wiley & Sons Ltd.

Chromosomal DNA Deletions Explain Phenotypic Characteristics of Two Antigenic Variants, Phase II and RSA 514 (Crazy), of the Coxiella burnetii Nine Mile Strain†

PubMed Central

Hoover, T. A.; Culp, D. W.; Vodkin, M. H.; Williams, J. C.; Thompson, H. A.

2002-01-01

After repeated passages through embyronated eggs, the Nine Mile strain of Coxiella burnetii exhibits antigenic variation, a loss of virulence characteristics, and transition to a truncated lipopolysaccharide (LPS) structure. In two independently derived strains, Nine Mile phase II and RSA 514, these phenotypic changes were accompanied by a large chromosomal deletion (M. H. Vodkin and J. C. Williams, J. Gen. Microbiol. 132:2587-2594, 1986). In the work reported here, additional screening of a cosmid bank prepared from the wild-type strain was used to map the deletion termini of both mutant strains and to accumulate all the segments of DNA that comprise the two deletions. The corresponding DNAs were then sequenced and annotated. The Nine Mile phase II deletion was completely nested within the deletion of the RSA 514 strain. Basic alignment and homology studies indicated that a large group of LPS biosynthetic genes, arranged in an apparent O-antigen cluster, was deleted in both variants. Database homologies identified, in particular, mannose pathway genes and genes encoding sugar methylases and nucleotide sugar epimerase-dehydratase proteins. Candidate genes for addition of sugar units to the core oligosaccharide for synthesis of the rare sugar 6-deoxy-3-C-methylgulose (virenose) were identified in the deleted region. Repeats, redundancies, paralogous genes, and two regions with reduced G+C contents were found within the deletions. PMID:12438347

Overexpression and Initial Characterization of the Chromosomal Aminoglycoside 3′-O-Phosphotransferase APH(3′)-IIb from Pseudomonas aeruginosa▿†

PubMed Central

Hainrichson, Mariana; Yaniv, Orit; Cherniavsky, Marina; Nudelman, Igor; Shallom-Shezifi, Dalia; Yaron, Sima; Baasov, Timor

2007-01-01

The chromosomal gene aph(3′)-IIb, encoding an aminoglycoside 3′-phosphotransferase in Pseudomonas aeruginosa, was cloned and overexpressed in Escherichia coli. The APH(3′)-IIb enzyme was purified as a monomer in a two-step procedure and was shown to phosphorylate its substrates at the C-3′-OH position, with kcat/Km values of 0.4 × 104 to 36 × 104 M−1 s−1. PMID:17088479

Characterization of the human lineage-specific pericentric inversion that distinguishes human chromosome 1 from the homologous chromosomes of the great apes.

PubMed

Szamalek, Justyna M; Goidts, Violaine; Cooper, David N; Hameister, Horst; Kehrer-Sawatzki, Hildegard

2006-08-01

The human and chimpanzee genomes are distinguishable in terms of ten gross karyotypic differences including nine pericentric inversions and a chromosomal fusion. Seven of these large pericentric inversions are chimpanzee-specific whereas two of them, involving human chromosomes 1 and 18, were fixed in the human lineage after the divergence of humans and chimpanzees. We have performed detailed molecular and computational characterization of the breakpoint regions of the human-specific inversion of chromosome 1. FISH analysis and sequence comparisons together revealed that the pericentromeric region of HSA 1 contains numerous segmental duplications that display a high degree of sequence similarity between both chromosomal arms. Detailed analysis of these regions has allowed us to refine the p-arm breakpoint region to a 154.2 kb interval at 1p11.2 and the q-arm breakpoint region to a 562.6 kb interval at 1q21.1. Both breakpoint regions contain human-specific segmental duplications arranged in inverted orientation. We therefore propose that the pericentric inversion of HSA 1 was mediated by intra-chromosomal non-homologous recombination between these highly homologous segmental duplications that had themselves arisen only recently in the human lineage by duplicative transposition.

Rescue of Targeted Regions of Mammalian Chromosomes by in Vivo Recombination in Yeast

PubMed Central

Kouprina, Natalya; Kawamoto, Kensaku; Barrett, J. Carl; Larionov, Vladimir; Koi, Minoru

1998-01-01

In contrast to other animal cell lines, the chicken pre-B cell lymphoma line, DT40, exhibits a high level of homologous recombination, which can be exploited to generate site-specific alterations in defined target genes or regions. In addition, the ability to generate human/chicken monochromosomal hybrids in the DT40 cell line opens a way for specific targeting of human genes. Here we describe a new strategy for direct isolation of a human chromosomal region that is based on targeting of the chromosome with a vector containing a yeast selectable marker, centromere, and an ARS element. This procedure allows rescue of the targeted region by transfection of total genomic DNA into yeast spheroplasts. Selection for the yeast marker results in isolation of chromosome sequences in the form of large circular yeast artificial chromosomes (YACs) up to 170 kb in size containing the targeted region. These YACs are generated by homologous recombination in yeast between common repeated sequences in the targeted chromosomal fragment. Alternatively, the targeted region can be rescued as a linear YACs when a YAC fragmentation vector is included in the yeast transformation mixture. Because the entire isolation procedure of the chromosomal region, once a target insertion is obtained, can be accomplished in ∼1 week, the new method greatly expands the utility of the homologous recombinationproficient DT40 chicken cell system. PMID:9647640

Structure and chromosomal localization of the human PD-1 gene (PDCD1)

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

Shinohara, T.; Ishida, Y.; Kawaichi, M.

1994-10-01

A cDNA encoding mouse PD-1, a member of the immunoglobulin superfamily, was previously isolated from apoptosis-induced cells by subtractive hybridization. To determine the structure and chromosomal location of the human PD-1 gene, we screened a human T cell cDNA library by mouse PD-1 probe and isolated a cDNA coding for the human PD-1 protein. The deduced amino acid sequence of human PD-1 was 60% identical to the mouse counterpart, and a putative tyrosine kinase-association motif was well conserved. The human PD-1 gene was mapped to 2q37.3 by chromosomal in situ hybridization. 7 refs., 3 figs.

A patient with polymerase E1 deficiency (POLE1): clinical features and overlap with DNA breakage/instability syndromes.

PubMed

Thiffault, Isabelle; Saunders, Carol; Jenkins, Janda; Raje, Nikita; Canty, Kristi; Sharma, Mukta; Grote, Lauren; Welsh, Holly I; Farrow, Emily; Twist, Greyson; Miller, Neil; Zwick, David; Zellmer, Lee; Kingsmore, Stephen F; Safina, Nicole P

2015-05-07

Chromosome instability syndromes are a group of inherited conditions associated with chromosomal instability and breakage, often leading to immunodeficiency, growth retardation and increased risk of malignancy. We performed exome sequencing on a girl with a suspected chromosome instability syndrome that manifested as growth retardation, microcephaly, developmental delay, dysmorphic features, poikiloderma, immune deficiency with pancytopenia, and myelodysplasia. She was homozygous for a previously reported splice variant, c.4444 + 3A > G in the POLE1 gene, which encodes the catalytic subunit of DNA polymerase E. This is the second family with POLE1-deficency, with the affected individual demonstrating a more severe phenotype than previously described.

Male infertility associated with de novo pericentric inversion of chromosome 1.

PubMed

Balasar, Özgür; Zamani, Ayşe Gül; Balasar, Mehmet; Acar, Hasan

2017-12-01

Inversion occurs after two breaks in a chromosome have happened and the segment rotates 180° before reinserting. Inversion carriers have produced abnormal gametes if there is an odd number crossing- over between the inverted and the normal homologous chromosomes causing a duplication or deletion. Reproductive risks such as infertility, abortion, stillbirth and birth of malformed child would be expected in that case. A 54-year- old male patient was consulted to our clinic for primary infertility. The routine chromosome study were applied using peripheral blood lymphocyte cultures and analyzed by giemsa-trypsin-giemsa (GTG) banding, and centromer banding (C-banding) stains. Y chromosome microdeletions in the azoospermia factor (AZF) regions were analyzed with polymerase chain reaction. Additional test such as fluorescence in situ hybridization (FISH) was used to detect the sex-determining region of the Y chromosome (SRY). Semen analysis showed azoospermia. A large pericentric inversion of chromosome 1 46,XY, inv(1) (p22q32) was found in routine chromosome analysis. No microdeletions were seen in AZF regions. In our patient the presence of SRY region was observed by using FISH technique with SRY-specific probe. Men who have pericentric inversion of chromosome 1, appear to be at risk for infertility brought about by spermatogenic breakdown. The etiopathogenic relationship between azoospermia and pericentric inversion of chromosome 1 is discussed.

Genome structure and primitive sex chromosome revealed in Populus

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

Tuskan, Gerald A; Yin, Tongming; Gunter, Lee E

We constructed a comprehensive genetic map for Populus and ordered 332 Mb of sequence scaffolds along the 19 haploid chromosomes in order to compare chromosomal regions among diverse members of the genus. These efforts lead us to conclude that chromosome XIX in Populus is evolving into a sex chromosome. Consistent segregation distortion in favor of the sub-genera Tacamahaca alleles provided evidence of divergent selection among species, particularly at the proximal end of chromosome XIX. A large microsatellite marker (SSR) cluster was detected in the distorted region even though the genome-wide distribute SSR sites was uniform across the physical map. Themore » differences between the genetic map and physical sequence data suggested recombination suppression was occurring in the distorted region. A gender-determination locus and an overabundance of NBS-LRR genes were also co-located to the distorted region and were put forth as the cause for divergent selection and recombination suppression. This hypothesis was verified by using fine-scale mapping of an integrated scaffold in the vicinity of the gender-determination locus. As such it appears that chromosome XIX in Populus is in the process of evolving from an autosome into a sex chromosome and that NBS-LRR genes may play important role in the chromosomal diversification process in Populus.« less

Chromosomal microarray analysis as the first-tier test for the identification of pathogenic copy number variants in chromosome 9 pericentric regions and its challenge.

PubMed

Wang, Jia-Chi; Boyar, Fatih Z

2016-01-01

Chromosomal microarray analysis (CMA) has been recommended and practiced routinely in the large reference laboratories of U.S.A. as the first-tier test for the postnatal evaluation of individuals with intellectual disability, autism spectrum disorders, and/or multiple congenital anomalies. Using CMA as a diagnostic tool and without a routine setting of fluorescence in situ hybridization with labeled bacterial artificial chromosome probes (BAC-FISH) in the large reference laboratories becomes a challenge in the characterization of chromosome 9 pericentric region. This region has a very complex genomic structure and contains a variety of heterochromatic and euchromatic polymorphic variants. These variants were usually studied by G-banding, C-banding and BAC-FISH analysis. Chromosomal microarray analysis (CMA) was not recommended since it may lead to false positive results. Here, we presented a cohort of four cases, in which high-resolution CMA was used as the first-tier test or simultaneously with G-banding analysis on the proband to identify pathogenic copy number variants (CNVs) in the whole genome. CMA revealed large pathogenic CNVs from chromosome 9 in 3 cases which also revealed different G-banding patterns between the two chromosome 9 homologues. Although we demonstrated that high-resolution CMA played an important role in the identification of pathogenic copy number variants in chromosome 9 pericentric regions, the lack of BAC-FISH analysis or other useful tools renders significant challenges in the characterization of chromosome 9 pericentric regions. None; it is not a clinical trial, and the cases were retrospectively collected and analyzed.

Analysis of the DNA sequence of a 15,500 bp fragment near the left telomere of chromosome XV from Saccharomyces cerevisiae reveals a putative sugar transporter, a carboxypeptidase homologue and two new open reading frames.

PubMed

Gamo, F J; Lafuente, M J; Casamayor, A; Ariño, J; Aldea, M; Casas, C; Herrero, E; Gancedo, C

1996-06-15

We report the sequence of a 15.5 kb DNA segment located near the left telomere of chromosome XV of Saccharomyces cerevisiae. The sequence contains nine open reading frames (ORFs) longer than 300 bp. Three of them are internal to other ones. One corresponds to the gene LGT3 that encodes a putative sugar transporter. Three adjacent ORFs were separated by two stop codons in frame. These ORFs presented homology with the gene CPS1 that encodes carboxypeptidase S. The stop codons were not found in the same sequence derived from another yeast strain. Two other ORFs without significant homology in databases were also found. One of them, O0420, is very rich in serine and threonine and presents a series of repeated or similar amino acid stretches along the sequence.

Chromosomal Mapping of Repetitive DNAs in Myiopsitta monachus and Amazona aestiva (Psittaciformes, Psittacidae) with Emphasis on the Sex Chromosomes.

PubMed

de Oliveira Furo, Ivanete; Kretschmer, Rafael; Dos Santos, Michelly S; de Lima Carvalho, Carlos A; Gunski, Ricardo J; O'Brien, Patrícia C M; Ferguson-Smith, Malcolm A; Cioffi, Marcelo B; de Oliveira, Edivaldo H C

2017-01-01

Here, for the first time, we describe the karyotype of Myiopsitta monachus (Psittacidae, Arini). We found 2n = 48, corresponding to the lowest diploid number observed in Neotropical Psittaciformes so far, with an uncommonly large W chromosome homomorphic to the Z. In order to better understand the evolution of the sex chromosomes in this species, we applied several molecular cytogenetic approaches, including C-banding, FISH mapping of repetitive DNAs (several microsatellite repeats), and whole-chromosome painting on metaphases of M. monachus. For comparison, another species belonging to the same tribe but with a smaller W chromosome (A. aestiva) was also analyzed. The results show that the constitutive heterochromatin has a very diverse distribution pattern in these species revealing heterochromatic blocks in the centromeric region of all chromosomes and in most of the length of the W chromosome in A. aestiva, while in M. monachus they were found in interstitial and telomeric regions. Concerning the microsatellites, only the sequence (CG)n produced signals on the W chromosome of A. aestiva, in the distal region of both arms. However, in M. monachus, (CAA)n, (CAG)n, and (CG)n probes were accumulated on the W chromosome, and, in addition, the sequence (CAG)n also hybridized to heterochromatic regions in macrochromosomes, as well as in microchromosomes. Based on these results, we suggest that the increase in length of the W chromosome in M. monachus is due to the amplification of repetitive elements, which highlights their significant role in the evolutionary process of sex chromosome differentiation. © 2017 S. Karger AG, Basel.

Characterisation of single domain ATP-binding cassette protien homologues of Theileria parva.

PubMed

Kibe, M K; Macklin, M; Gobright, E; Bishop, R; Urakawa, T; ole-MoiYoi, O K

2001-09-01

Two distinct genes encoding single domain, ATP-binding cassette transport protein homologues of Theileria parva were cloned and sequenced. Neither of the genes is tandemly duplicated. One gene, TpABC1, encodes a predicted protein of 593 amino acids with an N-terminal hydrophobic domain containing six potential membrane-spanning segments. A single discontinuous ATP-binding element was located in the C-terminal region of TpABC1. The second gene, TpABC2, also contains a single C-terminal ATP-binding motif. Copies of TpABC2 were present at four loci in the T. parva genome on three different chromosomes. TpABC1 exhibited allelic polymorphism between stocks of the parasite. Comparison of cDNA and genomic sequences revealed that TpABC1 contained seven short introns, between 29 and 84 bp in length. The full-length TpABC1 protein was expressed in insect cells using the baculovirus system. Application of antibodies raised against the recombinant antigen to western blots of T. parva piroplasm lysates detected an 85 kDa protein in this life-cycle stage.

Cloning and identification of a cDNA that encodes a novel human protein with thrombospondin type I repeat domain, hPWTSR.

PubMed

Chen, Jin-Zhong; Wang, Shu; Tang, Rong; Yang, Quan-Sheng; Zhao, Enpeng; Chao, Yaoqiong; Ying, Kang; Xie, Yi; Mao, Yu-Min

2002-09-01

A cDNA was isolated from the fetal brain cDNA library by high throughput cDNA sequencing. The 2390 bp cDNA with an open reading fragment (ORF) of 816 bp encodes a 272 amino acids putative protein with a thrombospondin type I repeat (TSR) domain and a cysteine-rich region at the N-terminus, so it is named hPWTSR. We used Northern blot detected two bands with length of about 3 kb and 4 kb respectively, which expressed in human adult tissues with different intensities. The expression pattern was verified by RT-PCR, revealing that the transcripts were expressed ubiquitously in fetal tissues and human tumor tissues too. However, the transcript was detected neither in ovarian carcinoma GI-102 nor in lung carcinoma LX-1. Blast analysis against NCBI database revealed that the new gene contained at least 5 exons and located in human chromosome 6q22.33. Our results demonstrate that the gene is a novel member of TSR supergene family.

Evolution and Variation of Renin Genes in Mice

PubMed Central

Dickinson, Douglas P.; Gross, Kenneth W.; Piccini, Nina; Wilson, Carol M.

1984-01-01

Inbred strains of mice carry Ren-1, a gene encoding the thermostable Renin-1 isozyme. Ren-1 is expressed at relatively low levels in mouse submandibular gland and kidney. Some strains also carry Ren-2, a gene encoding the thermolabile Renin-2 isozyme. Ren-2 is expressed at high levels in the mouse submandibular gland and at very low levels, if at all, in the kidney. Ren-1 and Ren-2 are closely linked on mouse chromosome 1, show extensive homology in coding and noncoding regions and provide a model for studying the regulation of gene expression. An investigation of renin genes and enzymatic activity in wild-derived mice identified several restriction site polymorphisms as well as putative variants in renin gene expression and protein structure. The number of renin genes carried by different subpopulations of wild-derived mice is consistent with the occurrence of a gene duplication event prior to the divergence of M. spretus (2.75–5.5 million yr ago). This conclusion is in agreement with a prior estimate based upon comparative sequence analysis of Ren-1 and Ren-2 from inbred laboratory mice. PMID:6389258

Amplifications of chromosomal region 20q13 as a prognostic indicator breast cancer

DOEpatents

Gray, Joe W.; Collins, Colin; Pinkel, Daniel; Kallioniemi, Olli-Pekka; Tanner, Minna M.

2001-01-01

The present invention relates to in situ hybridization methods for the identification of new chromosomal abnormalities associated with various diseases. In particular, it provides probes which are specific to a region of amplification in chromosome 20.

Use of the multipurpose transposon Tn KPK2 for the mutational analysis of chromosomal regions upstream and downstream of the sipF gene in Bradyrhizobium japonicum.

PubMed

Müller, P

2004-04-01

The DNA regions upstream and downstream of the Bradyrhizobium japonicum gene sipF were cloned by in vivo techniques and subsequently sequenced. In order to study the function of the predicted genes, a new transposon for in vitro mutagenesis, Tn KPK2, was constructed. This mutagenesis system has a number of advantages over other transposons. Tn KPK2 itself has no transposase gene, making transposition events stable. Extremely short inverted repeats minimize the length of the transposable element and facilitate the determination of the nucleotide sequence of the flanking regions. Since the transposable element carries a promoterless ' phoA reporter gene, the appearance of functional PhoA fusion proteins indicates that Tn KPK2 has inserted in a gene encoding a periplasmic or secreted protein. Although such events are extremely rare, because the transposon has to insert in-frame, in the correct orientation, and at an appropriate location in the target molecule, a direct screening procedure on agar indicator plates permits the identification of candidate clones from large numbers of colonies. In this study, Tn KPK2 was used for the construction of various symbiotic mutants of B. japonicum. One of the mutant strains, A2-10, which is defective in a gene encoding a protein that comigrates with bacterioferritin ( bcpB), was found to induce the formation of small and ineffective nodules.

Genome organization and DNA methylation patterns of B chromosomes in the red fox and Chinese raccoon dogs.

PubMed

Bugno-Poniewierska, Monika; Solek, Przemysław; Wronski, Mariusz; Potocki, Leszek; Jezewska-Witkowska, Grażyna; Wnuk, Maciej

2014-12-01

The molecular structure of B chromosomes (Bs) is relatively well studied. Previous research demonstrates that Bs of various species usually contain two types of repetitive DNA sequences, satellite DNA and ribosomal DNA, but Bs also contain genes encoding histone proteins and many others. However, many questions remain regarding the origin and function of these chromosomes. Here, we focused on the comparative cytogenetic characteristics of the red fox and Chinese raccoon dog B chromosomes with particular attention to the distribution of repetitive DNA sequences and their methylation status. We confirmed that the small Bs of the red fox show a typical fluorescent telomeric distal signal, whereas medium-sized Bs of the Chinese raccoon dog were characterized by clusters of telomeric sequences along their length. We also found different DNA methylation patterns for the B chromosomes of both species. Therefore, we concluded that DNA methylation may maintain the transcriptional inactivation of DNA sequences localized to B chromosomes and may prevent genetic unbalancing and several negative phenotypic effects. © 2014 The Authors.

Chromosome-based survey sequencing reveals the genome organization of wild wheat progenitor Triticum dicoccoides.

PubMed

Akpinar, Bala Ani; Biyiklioglu, Sezgi; Alptekin, Burcu; Havránková, Miroslava; Vrána, Jan; Doležel, Jaroslav; Distelfeld, Assaf; Hernandez, Pilar; Budak, Hikmet

2018-05-04

Wild emmer wheat (Triticum turgidum ssp. dicoccoides) is the progenitor of wheat. We performed chromosome-based survey sequencing of the 14 chromosomes, examining repetitive sequences, protein-coding genes, miRNA/target pairs and tRNA genes, as well as syntenic relationships with related grasses. We found considerable differences in the content and distribution of repetitive sequences between the A and B subgenomes. The gene contents of individual chromosomes varied widely, not necessarily correlating with chromosome size. We catalogued candidate agronomically important loci, along with new alleles and flanking sequences that can be used to design exome sequencing. Syntenic relationships and virtual gene orders revealed several small-scale evolutionary rearrangements, in addition to providing evidence for the 4AL-5AL-7BS translocation in wild emmer wheat. Chromosome-based sequence assemblies contained five novel miRNA families, among 59 families putatively encoded in the entire genome which provide insight into the domestication of wheat and an overview of the genome content and organization. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Sequence and analysis of chromosome 2 of the plant Arabidopsis thaliana.

PubMed

Lin, X; Kaul, S; Rounsley, S; Shea, T P; Benito, M I; Town, C D; Fujii, C Y; Mason, T; Bowman, C L; Barnstead, M; Feldblyum, T V; Buell, C R; Ketchum, K A; Lee, J; Ronning, C M; Koo, H L; Moffat, K S; Cronin, L A; Shen, M; Pai, G; Van Aken, S; Umayam, L; Tallon, L J; Gill, J E; Adams, M D; Carrera, A J; Creasy, T H; Goodman, H M; Somerville, C R; Copenhaver, G P; Preuss, D; Nierman, W C; White, O; Eisen, J A; Salzberg, S L; Fraser, C M; Venter, J C

1999-12-16

Arabidopsis thaliana (Arabidopsis) is unique among plant model organisms in having a small genome (130-140 Mb), excellent physical and genetic maps, and little repetitive DNA. Here we report the sequence of chromosome 2 from the Columbia ecotype in two gap-free assemblies (contigs) of 3.6 and 16 megabases (Mb). The latter represents the longest published stretch of uninterrupted DNA sequence assembled from any organism to date. Chromosome 2 represents 15% of the genome and encodes 4,037 genes, 49% of which have no predicted function. Roughly 250 tandem gene duplications were found in addition to large-scale duplications of about 0.5 and 4.5 Mb between chromosomes 2 and 1 and between chromosomes 2 and 4, respectively. Sequencing of nearly 2 Mb within the genetically defined centromere revealed a low density of recognizable genes, and a high density and diverse range of vestigial and presumably inactive mobile elements. More unexpected is what appears to be a recent insertion of a continuous stretch of 75% of the mitochondrial genome into chromosome 2.

Replication profile of Saccharomyces cerevisiae chromosome VI.

PubMed

Friedman, K L; Brewer, B J; Fangman, W L

1997-11-01

An understanding of the replication programme at the genome level will require the identification and characterization of origins of replication through large, contiguous regions of DNA. As a step toward this goal, origin efficiencies and replication times were determined for 10 ARSs spanning most of the 270 kilobase (kb) chromosome VI of Saccharomyces cerevisiae. Chromosome VI shows a wide variation in the percentage of cell cycles in which different replication origins are utilized. Most of the origins are activated in only a fraction of cells, suggesting that the pattern of origin usage on chromosome VI varies greatly within the cell population. The replication times of fragments containing chromosome VI origins show a temporal pattern that has been recognized on other chromosomes--the telomeres replicate late in S phase, while the central region of the chromosome replicates early. As demonstrated here for chromosome VI, analysis of the direction of replication fork movement along a chromosome and determination of replication time by measuring a period of hemimethylation may provide an efficient means of surveying origin activity over large regions of the genome.

Microsatellites within the feline androgen receptor are suitable for X chromosome-linked clonality testing in archival material.

PubMed

Farwick, Nadine M; Klopfleisch, Robert; Gruber, Achim D; Weiss, Alexander Th A

2017-04-01

Objectives A hallmark of neoplasms is their origin from a single cell; that is, clonality. Many techniques have been developed in human medicine to utilise this feature of tumours for diagnostic purposes. One approach is X chromosome-linked clonality testing using polymorphisms of genes encoded by genes on the X chromosome. The aim of this study was to determine if the feline androgen receptor gene was suitable for X chromosome-linked clonality testing. Methods The feline androgen receptor gene was characterised and used to test clonality of feline lymphomas by PCR and polyacrylamide gel electrophoresis, using archival formalin-fixed, paraffin-embedded material. Results Clonality of the feline lymphomas under study was confirmed and the gene locus was shown to represent a suitable target in clonality testing. Conclusions and relevance Because there are some pitfalls of using X chromosome-linked clonality testing, further studies are necessary to establish this technique in the cat.

Small Molecule Disrupts Abnormal Gene Fusion Associated with Leukemia | Center for Cancer Research

Cancer.gov

Rare chromosomal abnormalities, called chromosomal translocations, in which part of a chromosome breaks off and becomes attached to another chromosome, can result in the generation of chimeric proteins. These aberrant proteins have unpredictable, and sometimes harmful, functions, including uncontrolled cell growth that can lead to cancer. One type of translocation, in which a portion of the gene encoding nucleoporin 98 (NUP98)—one of about 50 proteins comprising the nuclear pore complex through which proteins are shuttled into and out of the nucleus—fuses with another gene, has been shown to result in improper histone modifications. These abnormalities alter the gene expression patterns of certain types of hematopoietic, or blood-forming, stem cells, resulting primarily in overexpression of the Hoxa7, Hoxa9,and Hoxa10 genes. NUP98 chromosomal translocations have been associated with many types of leukemia, including acute myeloid leukemia (AML), acute lymphoid leukemia (ALL), chronic myeloid leukemia in blast crisis (CML-bc), and myelodysplastic syndrome (MDS).

Transcriptome Reprogramming by Plasmid-Encoded Transcriptional Regulators Is Required for Host Niche Adaption of a Macrophage Pathogen

PubMed Central

Coulson, Garry B.; Miranda-CasoLuengo, Aleksandra A.; Miranda-CasoLuengo, Raúl; Wang, Xiaoguang; Oliver, Jenna; Willingham-Lane, Jennifer M.

2015-01-01

Rhodococcus equi is a facultative intracellular pathogen of macrophages, relying on the presence of a conjugative virulence plasmid harboring a 21-kb pathogenicity island (PAI) for growth in host macrophages. The PAI encodes a family of 6 virulence-associated proteins (Vaps) in addition to 20 other proteins. The contribution of these to virulence has remained unclear. We show that the presence of only 3 virulence plasmid genes (of 73 in total) is required and sufficient for intracellular growth. These include a single vap family member, vapA, and two PAI-located transcriptional regulators, virR and virS. Both transcriptional regulators are essential for wild-type-level expression of vapA, yet vapA expression alone is not sufficient to allow intracellular growth. A whole-genome microarray analysis revealed that VirR and VirS substantially integrate themselves into the chromosomal regulatory network, significantly altering the transcription of 18% of all chromosomal genes. This pathoadaptation involved significant enrichment of select gene ontologies, in particular, enrichment of genes involved in transport processes, energy production, and cellular metabolism, suggesting a major change in cell physiology allowing the bacterium to grow in the hostile environment of the host cell. The results suggest that following the acquisition of the virulence plasmid by an avirulent ancestor of R. equi, coevolution between the plasmid and the chromosome took place, allowing VirR and VirS to regulate the transcription of chromosomal genes in a process that ultimately promoted intracellular growth. Our findings suggest a mechanism for cooption of existing chromosomal traits during the evolution of a pathogenic bacterium from an avirulent saprophyte. PMID:26015480

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.

Bioinformatic analysis of the nucleotide binding site-encoding disease-resistance genes in foxtail millet (Setaria italica (L.) Beauv.).

PubMed

Zhu, Y B; Xie, X Q; Li, Z Y; Bai, H; Dong, L; Dong, Z P; Dong, J G

2014-08-28

The nucleotide-binding site (NBS) disease-resistance genes are the largest category of plant disease-resistance gene analogs. The complete set of disease-resistant candidate genes, which encode the NBS sequence, was filtered in the genomes of two varieties of foxtail millet (Yugu1 and 'Zhang gu'). This study investigated a number of characteristics of the putative NBS genes, such as structural diversity and phylogenetic relationships. A total of 269 and 281 NBS-coding sequences were identified in Yugu1 and 'Zhang gu', respectively. When the two databases were compared, 72 genes were found to be identical and 164 genes showed more than 90% similarity. Physical positioning and gene family analysis of the NBS disease-resistance genes in the genome revealed that the number of genes on each chromosome was similar in both varieties. The eighth chromosome contained the largest number of genes and the ninth chromosome contained the lowest number of genes. Exactly 34 gene clusters containing the 161 genes were found in the Yugu1 genome, with each cluster containing 4.7 genes on average. In comparison, the 'Zhang gu' genome possessed 28 gene clusters, which had 151 genes, with an average of 5.4 genes in each cluster. The largest gene cluster, located on the eighth chromosome, contained 12 genes in the Yugu1 database, whereas it contained 16 genes in the 'Zhang gu' database. The classification results showed that the CC-NBS-LRR gene made up the largest part of each chromosome in the two databases. Two TIR-NBS genes were also found in the Yugu1 genome.

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

D'Aiuto, L.; Marzella, R.; Archidiacono, N.

The authors have isolated and characterized two human alphoid DNA clones: p4n1/4 and pZ4.1. Clone p4n1/4 identifies specifically the centromeric region of chromosome 4; pZ4.1 recognizes a subset of alphoid DNA shared by chromosomes 4 and 9. The specificity was determined using fluorescence in situ hybridization experiments on metaphase spreads and Southern blotting analysis of human-hamster somatic cell hybrids. The genomic organization of both subsets was also investigated. Comparative mapping on chimpanzee and gorilla chromosomes was performed. p4n1/4 hybridizes to chimpanzee chromosomes 11 and 13, homologs of human chromosomes 9 and 2q, respectively. On gorilla metaphase spreads, p4n1/4 hybridizes exclusivelymore » to the centromeric region of chromosome 19, partially homologous to human chromosome 17. No hybridization signal was detected on chromosome 3 of both chimpanzee and gorilla, in both species homolog of human chromosome 4. Identical comparative mapping results were obtained using pZ4.1 probe, although the latter recognizes an alphoid subset distinct from the one recognized by p4n1/4. The implications of these results in the evolution of centromeric regions of primate chromosomes are discussed. 33 refs., 4 figs.« less

Telomere structure and maintenance gene variants and risk of five cancer types

PubMed Central

Karami, Sara; Han, Younghun; Pande, Mala; Cheng, Iona; Rudd, James; Pierce, Brandon L.; Nutter, Ellen L.; Schumacher, Fredrick R.; Kote-Jarai, Zsofia; Lindstrom, Sara; Witte, John S.; Fang, Shenying; Han, Jiali; Kraft, Peter; Hunter, David; Song, Fengju; Hung, Rayjean J.; McKay, James; Gruber, Stephen B.; Chanock, Stephen J.; Risch, Angela; Shen, Hongbing; Haiman, Christopher A.; Boardman, Lisa; Ulrich, Cornelia M.; Casey, Graham; Peters, Ulrike; Al Olama, Ali Amin; Berchuck, Andrew; Berndt, Sonja I.; Bezieau, Stephane; Brennan, Paul; Brenner, Hermann; Brinton, Louise; Caporaso, Neil; Chan, Andrew T.; Chang-Claude, Jenny; Christiani, David C.; Cunningham, Julie M.; Easton, Douglas; Eeles, Rosalind A.; Eisen, Timothy; Gala, Manish; Gallinger, Steven J.; Gayther, Simon A.; Goode, Ellen L.; Grönberg, Henrik; Henderson, Brian E.; Houlston, Richard; Joshi, Amit D.; Küry, Sébastien; Landi, Mari T.; Le Marchand, Loic; Muir, Kenneth; Newcomb, Polly A.; Permuth-Wey, Jenny; Pharoah, Paul; Phelan, Catherine; Potter, John D.; Ramus, Susan J.; Risch, Harvey; Schildkraut, Joellen; Slattery, Martha L.; Song, Honglin; Wentzensen, Nicolas; White, Emily; Wiklund, Fredrik; Zanke, Brent W.; Sellers, Thomas A.; Zheng, Wei; Chatterjee, Nilanjan; Amos, Christopher I.; Doherty, Jennifer A.

2016-01-01

Telomeres cap chromosome ends, protecting them from degradation, double-strand breaks, and end-to-end fusions. Telomeres are maintained by telomerase, a reverse transcriptase encoded by TERT, and an RNA template encoded by TERC. Loci in the TERT and adjoining CLPTM1L region are associated with risk of multiple cancers. We therefore investigated associations between variants in 22 telomere structure and maintenance gene regions and colorectal, breast, prostate, ovarian, and lung cancer risk. We performed subset-based meta-analyses of 204,993 directly-measured and imputed SNPs among 61,851 cancer cases and 74,457 controls of European descent. Independent associations for SNP minor alleles were identified using sequential conditional analysis (with gene-level P-value cutoffs ≤3.08×10−5). Of the thirteen independent SNPs observed to be associated with cancer risk, novel findings were observed for seven loci. Across the TERT-CLPTML1 region, rs12655062 was associated positively with prostate cancer, and inversely with colorectal and ovarian cancers, and rs115960372 was associated positively with prostate cancer. Across the TERC region, rs75316749 was positively associated with colorectal, breast, ovarian, and lung cancers. Across the DCLRE1B region, rs974404 and rs12144215 were inversely associated with prostate and lung cancers, and colorectal, breast, and ovarian cancers, respectively. Near POT1, rs116895242 was inversely associated with colorectal, ovarian, and lung cancers, and RTEL1 rs34978822 was inversely associated with prostate and lung cancers. The complex association patterns in telomere-related genes across cancer types may provide insight into mechanisms through which telomere dysfunction in different tissues influences cancer risk. PMID:27459707

A Commensal Gone Bad: Complete Genome Sequence of the Prototypical Enterotoxigenic Escherichia coli Strain H10407

DTIC Science & Technology

2010-11-01

and Escherichia ferguso- . TABLE 2. General characteristics of the plasm ids from ETEC strains H10407 and E1392/75 Value in E. c·oli: Characteristic...0352). consetved proteins with unknown func- tions (CDSs 0673 to 0678), a flavoprotein electron transfer system (CDSs 1730 to 1734), the colanic...mediating diarrhea are not chromosomally encoded. indicating that the essential virulence factors are encoded on the plasm ids (61 ). Potentia l

Development of a quantitative pachytene chromosome map and its unification with somatic chromosome and linkage maps of rice (Oryza sativa L.).

PubMed

Ohmido, Nobuko; Iwata, Aiko; Kato, Seiji; Wako, Toshiyuki; Fukui, Kiichi

2018-01-01

A quantitative pachytene chromosome map of rice (Oryza sativa L.) was developed using imaging methods. The map depicts not only distribution patterns of chromomeres specific to pachytene chromosomes, but also the higher order information of chromosomal structures, such as heterochromatin (condensed regions), euchromatin (decondensed regions), the primary constrictions (centromeres), and the secondary constriction (nucleolar organizing regions, NOR). These features were image analyzed and quantitatively mapped onto the map by Chromosome Image Analyzing System ver. 4.0 (CHIAS IV). Correlation between H3K9me2, an epigenetic marker and formation and/or maintenance of heterochromatin, thus was, clearly visualized. Then the pachytene chromosome map was unified with the existing somatic chromosome and linkage maps by physically mapping common DNA markers among them, such as a rice A genome specific tandem repeat sequence (TrsA), 5S and 45S ribosomal RNA genes, five bacterial artificial chromosome (BAC) clones, four P1 bacteriophage artificial chromosome (PAC) clones using multicolor fluorescence in situ hybridization (FISH). Detailed comparison between the locations of the DNA probes on the pachytene chromosomes using multicolor FISH, and the linkage map enabled determination of the chromosome number and short/long arms of individual pachytene chromosomes using the chromosome number and arm assignment designated for the linkage map. As a result, the quantitative pachytene chromosome map was unified with two other major rice chromosome maps representing somatic prometaphase chromosomes and genetic linkages. In conclusion, the unification of the three rice maps serves as an indispensable basic information, not only for an in-depth comparison between genetic and chromosomal data, but also for practical breeding programs.

Genomic structure and paralogous regions of the inversion breakpoint occurring between human chromosome 3p12.3 and orangutan chromosome 2.

PubMed

Yue, Y; Grossmann, B; Tsend-Ayush, E; Grützner, F; Ferguson-Smith, M A; Yang, F; Haaf, T

2005-01-01

Intrachromosomal duplications play a significant role in human genome pathology and evolution. To better understand the molecular basis of evolutionary chromosome rearrangements, we performed molecular cytogenetic and sequence analyses of the breakpoint region that distinguishes human chromosome 3p12.3 and orangutan chromosome 2. FISH with region-specific BAC clones demonstrated that the breakpoint-flanking sequences are duplicated intrachromosomally on orangutan 2 and human 3q21 as well as at many pericentromeric and subtelomeric sites throughout the genomes. Breakage and rearrangement of the human 3p12.3-homologous region in the orangutan lineage were associated with a partial loss of duplicated sequences in the breakpoint region. Consistent with our FISH mapping results, computational analysis of the human chromosome 3 genomic sequence revealed three 3p12.3-paralogous sequence blocks on human chromosome 3q21 and smaller blocks on the short arm end 3p26-->p25. This is consistent with the view that sequences from an ancestral site at 3q21 were duplicated at 3p12.3 in a common ancestor of orangutan and humans. Our results show that evolutionary chromosome rearrangements are associated with microduplications and microdeletions, contributing to the DNA differences between closely related species. Copyright (c) 2005 S. Karger AG, Basel.

Amplifications of chromosomal region 20q13 as a prognostic indicator in breast cancer

DOEpatents

Gray, Joe W.; Collins, Colin; Pinkel, Daniel; Kallioniemi, Olli-Pekka; Tanner, Minna M.

1998-01-01

The present invention relates to in situ hybridization methods for the identification of new chromosomal abnormalities associated with various diseases. In particular, it provides probes which are specific to a region of amplification in chromosome 20.

Histone deacetylase inhibition rescues gene knockout levels achieved with integrase-defective lentiviral vectors encoding zinc-finger nucleases.

PubMed

Pelascini, Laetitia P L; Maggio, Ignazio; Liu, Jin; Holkers, Maarten; Cathomen, Toni; Gonçalves, Manuel A F V

2013-12-01

Zinc-finger nucleases (ZFNs) work as dimers to induce double-stranded DNA breaks (DSBs) at predefined chromosomal positions. In doing so, they constitute powerful triggers to edit and to interrogate the function of genomic sequences in higher eukaryotes. A preferred route to introduce ZFNs into somatic cells relies on their cotransduction with two integrase-defective lentiviral vectors (IDLVs) each encoding a monomer of a functional heterodimeric pair. The episomal nature of IDLVs diminishes the risk of genotoxicity and ensures the strict transient expression profile necessary to minimize deleterious effects associated with long-term ZFN activity. However, by deploying IDLVs and conventional lentiviral vectors encoding HPRT1- or eGFP-specific ZFNs, we report that DSB formation at target alleles is limited after IDLV-mediated ZFN transfer. This IDLV-specific underperformance stems, to a great extent, from the activity of chromatin-remodeling histone deacetylases (HDACs). Importantly, the prototypic and U.S. Food and Drug Administration-approved inhibitors of metal-dependent HDACs, trichostatin A and vorinostat, respectively, did not hinder illegitimate recombination-mediated repair of targeted chromosomal DSBs. This allowed rescuing IDLV-mediated site-directed mutagenesis to levels approaching those achieved by using their isogenic chromosomally integrating counterparts. Hence, HDAC inhibition constitutes an efficacious expedient to incorporate in genome-editing strategies based on transient IDLV-mediated ZFN expression. Finally, we compared two of the most commonly used readout systems to measure targeted gene knockout activities based on restriction and mismatch-sensitive endonucleases. These experiments indicate that these enzymatic assays display a similar performance.

Cytogenetic Analysis of Chromosome 3 in DROSOPHILA MELANOGASTER: Mapping of the Proximal Portion of the Right Arm

PubMed Central

Duncan, Ian W.; Kaufman, Thomas C.

1975-01-01

In order to define more precisely the most proximal portion of chromosome 3R in Drosophila melanogaster, several new chromosome aberrations involving this region have been recovered and analyzed. These new arrangements were recovered as induced reversions of two dominant mutations, AntpNs and dsxD, located in the region of interest. The results of the analysis have allowed the localization of several existing mutations, have further elucidated the complex homoeotic locus which resides in this region, and have confirmed the efficacy of this type of screen in the analysis of specific chromosome regions. PMID:811500

Small supernumerary marker chromosome derived from proximal p-arm of chromosome 2: identification by fluorescent in situ hybridization.

PubMed

Lasan Trcić, Ruzica; Hitrec, Vlasta; Letica, Ljiljana; Cuk, Mario; Begović, Davor

2003-08-01

Conventional cytogenetics detected an interstitial deletion of proximal region of p-arm of chromosome 2 in a 6-month-old boy with a phenotype slightly resembling Down's syndrome. The deletion was inherited from the father, whose karyotype revealed a small ring-shaped marker chromosome, in addition to interstitial deletion. Fluorescence in situ hybridization identified the marker, which consisted of the proximal region of the p-arm of chromosome 2, including a part of its centromere. This case shows that molecular cytogenetic analysis can reveal the mechanism of the formation of the marker chromosome.

Construction of a DNA library representing 15q11-13 by subtraction of two flow sorted marker chromosome-specific libraries

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

Blennow, E.; Werelius, B.; Nordenskjoeld, M.

Constitutional extra {open_quotes}marker chromosomes{close_quotes} are found in {approx}0.5/1000 of newborns. Of these, 50% are inverted duplications of the pericentromeric region of chromosome 15, including two variants; (1) inv dup(15)(pter{yields}q11:q11{yields}pter) and (2) inv dup(15) (pter{yields}q12-13::q12-13{yields}pter). Variant (1) is found in phenotypically normal individuals, whereas variant (2) will produce a typical clinical picture including mental retardation, autism, hyperactivity and discrete dysmorphic features. Fluorescence in situ hybridization (FISH) using single copy probes from the Prader-Willi region confirms these observations as well as chromosome painting using a flow-sorted marker chromosome-specific library from a variant (1) marker, hybridized to the chromosomes of a patient withmore » a variant (2) marker chromosome. Followingly, a flow-sorted biotinylated variant (1) library was subtracted from a non-labeled variant (2) library using magnetic beads and subsequent amplification by degenerate oligonucleotide-primed PCR (DOP-PCR). The successful result was demonstrated by using the amplified material for chromosome painting on chromosome slides from variant (1) and variant (2) patients. We have constructed a library from 15q11-13. This region contains genes producing a specific abnormal phenotype when found in a tri- or tetrasomic state. The region also contains the genes responsible for the Prader-Willi and Angelman syndromes when the paternal/maternal copy is missing, respectively. It is therefore a region where parental imprinting plays an important role. The isolated library may be used to isolate single copy clones which will allow further investigations of this region.« less

Fluorescence in situ hybridization evaluation of chromosome deletion patterns in prostate cancer.

PubMed

Huang, S F; Xiao, S; Renshaw, A A; Loughlin, K R; Hudson, T J; Fletcher, J A

1996-11-01

Various nonrandom chromosomal aberrations have been identified in prostate carcinoma. These aberrations include deletions of several chromosome regions, particularly the chromosome 8 short arm. Large-scale numerical aberrations, reflected in aberrant DNA ploidy, are also found in a minority of cases. However, it is unclear whether prostate carcinomas contain aberrations of certain chromosome regions that are deleted frequently in other common types of cancer. In this study, we performed dual-color fluorescence in situ hybridization on intact nuclei from touch preparations of 16 prostate cancers. Chromosome copy number was determined using pericentromeric probes, whereas potential chromosome arm deletions were evaluated using yeast artificial chromosome (YAC) and P1 probes. Two YAC probes targeted chromosome 8 short arm regions known to be deleted frequently in prostate cancer. Other YACs and P1s were for chromosome regions, including 1p22, 3p14, 6q21, 9p21, and 22q12, that are deletion targets in a variety of cancers although not extensively studied in prostate cancer. Hybridization efficiencies and signal intensities were excellent for both repeat sequence (alpha-satellite) and single, copy (YAC and P1) fluorescence in situ hybridization probes. Of 16 prostate cancers, 11 had clonal aberrations of 1 or more of the 13 chromosome regions evaluated, and 10 cases (62.5%) had 8p deletions, including 4 cases with 8p deletion in virtually all cells and aneuploidy in only a subset of those deleted cells. Deletions at 3p14, 6q21, and 22q12 were identified in 2, 1, and 1 case, respectively, and each of those cases had a similarly sized cell population with 8p deletion. These studies confirm 8p deletion in the majority of prostate carcinomas. 8p deletions appear to be early events in prostate tumorigenesis, often antedating aneuploidy. Fluorescence in situ hybridization strategies incorporating pericentromeric and single-copy regional chromosome probes offer a powerful and efficient means for determining frequency and progression of oncogenetic events in prostate cancer.

[Late-replicating regions in salivary gland polytene chromosomes of Drosophila melanogaster].

PubMed

Kolesnikov, T D; Andreenkova, N G; Beliaeva, E S; Goncharov, F P; Zykova, T Iu; Boldyreva, L V; Pokholkova, g V; Zhimulev, I F

2013-01-01

About 240 specific regions that are replicated at the very end of the S-phase have been identified in D. melanogaster polytene chromosomes. These regions have a repressive chromatine state, low gene density, long intergenic distances and are enriched in tissue specific genes. In polytene chromosomes, about a quarter of these regions have no enough time to complete replication. As a result, underreplication zones represented by fewer DNA copy number, appear. We studied 60 chromosome regions that demonstrated the most pronounced under-replication. By comparing the location of these regions on a molecular map with syntenic blocks found earlier for Drosophila species by von Grotthuss et al., 2010, we have shown that across the genus Drosophila, these regions tend to have conserved gene order. This forces us to assume the existence of evolutionary mechanisms aimed at maintaining the integrity of these regions.

GDH3 encodes a glutamate dehydrogenase isozyme, a previously unrecognized route for glutamate biosynthesis in Saccharomyces cerevisiae.

PubMed Central

Avendaño, A; Deluna, A; Olivera, H; Valenzuela, L; Gonzalez, A

1997-01-01

It has been considered that the yeast Saccharomyces cerevisiae, like many other microorganisms, synthesizes glutamate through the action of NADP+-glutamate dehydrogenase (NADP+-GDH), encoded by GDH1, or through the combined action of glutamine synthetase and glutamate synthase (GOGAT), encoded by GLN1 and GLT1, respectively. A double mutant of S. cerevisiae lacking NADP+-GDH and GOGAT activities was constructed. This strain was able to grow on ammonium as the sole nitrogen source and thus to synthesize glutamate through an alternative pathway. A computer search for similarities between the GDH1 nucleotide sequence and the complete yeast genome was carried out. In addition to identifying its cognate sequence at chromosome XIV, the search found that GDH1 showed high identity with a previously recognized open reading frame (GDH3) of chromosome I. Triple mutants impaired in GDH1, GLT1, and GDH3 were obtained. These were strict glutamate auxotrophs. Our results indicate that GDH3 plays a significant physiological role, providing glutamate when GDH1 and GLT1 are impaired. This is the first example of a microorganism possessing three pathways for glutamate biosynthesis. PMID:9287019

Mating-Type Genes and MAT Switching in Saccharomyces cerevisiae

PubMed Central

Haber, James E.

2012-01-01

Mating type in Saccharomyces cerevisiae is determined by two nonhomologous alleles, MATa and MATα. These sequences encode regulators of the two different haploid mating types and of the diploids formed by their conjugation. Analysis of the MATa1, MATα1, and MATα2 alleles provided one of the earliest models of cell-type specification by transcriptional activators and repressors. Remarkably, homothallic yeast cells can switch their mating type as often as every generation by a highly choreographed, site-specific homologous recombination event that replaces one MAT allele with different DNA sequences encoding the opposite MAT allele. This replacement process involves the participation of two intact but unexpressed copies of mating-type information at the heterochromatic loci, HMLα and HMRa, which are located at opposite ends of the same chromosome-encoding MAT. The study of MAT switching has yielded important insights into the control of cell lineage, the silencing of gene expression, the formation of heterochromatin, and the regulation of accessibility of the donor sequences. Real-time analysis of MAT switching has provided the most detailed description of the molecular events that occur during the homologous recombinational repair of a programmed double-strand chromosome break. PMID:22555442

A novel family of integrases associated with prophages and genomic islands integrated within the tRNA-dihydrouridine synthase A (dusA) gene

PubMed Central

Farrugia, Daniel N.; Elbourne, Liam D. H.; Mabbutt, Bridget C.; Paulsen, Ian T.

2015-01-01

Genomic islands play a key role in prokaryotic genome plasticity. Genomic islands integrate into chromosomal loci such as transfer RNA genes and protein coding genes, whilst retaining various cargo genes that potentially bestow novel functions on the host organism. A gene encoding a putative integrase was identified at a single site within the 5′ end of the dusA gene in the genomes of over 200 bacteria. This integrase was discovered to be a component of numerous genomic islands, which appear to share a target site within the dusA gene. dusA encodes the tRNA-dihydrouridine synthase A enzyme, which catalyses the post-transcriptional reduction of uridine to dihydrouridine in tRNA. Genomic islands encoding homologous dusA-associated integrases were found at a much lower frequency within the related dusB and dusC genes, and non-dus genes. Excision of these dusA-associated islands from the chromosome as circularized intermediates was confirmed by polymerase chain reaction. Analysis of the dusA-associated islands indicated that they were highly diverse, with the integrase gene representing the only universal common feature. PMID:25883135

Identification of accessory genome regions in poultry Clostridium perfringens isolates carrying the netB plasmid.

PubMed

Lepp, D; Gong, J; Songer, J G; Boerlin, P; Parreira, V R; Prescott, J F

2013-03-01

Necrotic enteritis (NE) is an economically important disease of poultry caused by certain Clostridium perfringens type A strains. NE pathogenesis involves the NetB toxin, which is encoded on a large conjugative plasmid within a 42-kb pathogenicity locus. Recent multilocus sequence type (MLST) studies have identified two predominant NE-associated clonal groups, suggesting that host genes are also involved in NE pathogenesis. We used microarray comparative genomic hybridization (CGH) to assess the gene content of 54 poultry isolates from birds that were healthy or that suffered from NE. A total of 400 genes were variably present among the poultry isolates and nine nonpoultry strains, many of which had putative functions related to nutrient uptake and metabolism and cell wall and capsule biosynthesis. The variable genes were organized into 142 genomic regions, 49 of which contained genes significantly associated with netB-positive isolates. These regions included three previously identified NE-associated loci as well as several apparent fitness-related loci, such as a carbohydrate ABC transporter, a ferric-iron siderophore uptake system, and an adhesion locus. Additional loci were related to plasmid maintenance. Cluster analysis of the CGH data grouped all of the netB-positive poultry isolates into two major groups, separated according to two prevalent clonal groups based on MLST analysis. This study identifies chromosomal loci associated with netB-positive poultry strains, suggesting that the chromosomal background can confer a selective advantage to NE-causing strains, possibly through mechanisms involving iron acquisition, carbohydrate metabolism, and plasmid maintenance.

Regulatory and evolutionary signatures of sex-biased genes on both the X chromosome and the autosomes.

PubMed

Shen, Jiangshan J; Wang, Ting-You; Yang, Wanling

2017-11-02

Sex is an important but understudied factor in the genetics of human diseases. Analyses using a combination of gene expression data, ENCODE data, and evolutionary data of sex-biased gene expression in human tissues can give insight into the regulatory and evolutionary forces acting on sex-biased genes. In this study, we analyzed the differentially expressed genes between males and females. On the X chromosome, we used a novel method and investigated the status of genes that escape X-chromosome inactivation (escape genes), taking into account the clonality of lymphoblastoid cell lines (LCLs). To investigate the regulation of sex-biased differentially expressed genes (sDEG), we conducted pathway and transcription factor enrichment analyses on the sDEGs, as well as analyses on the genomic distribution of sDEGs. Evolutionary analyses were also conducted on both sDEGs and escape genes. Genome-wide, we characterized differential gene expression between sexes in 462 RNA-seq samples and identified 587 sex-biased genes, or 3.2% of the genes surveyed. On the X chromosome, sDEGs were distributed in evolutionary strata in a similar pattern as escape genes. We found a trend of negative correlation between the gene expression breadth and nonsynonymous over synonymous mutation (dN/dS) ratios, showing a possible pleiotropic constraint on evolution of genes. Genome-wide, nine transcription factors were found enriched in binding to the regions surrounding the transcription start sites of female-biased genes. Many pathways and protein domains were enriched in sex-biased genes, some of which hint at sex-biased physiological processes. These findings lend insight into the regulatory and evolutionary forces shaping sex-biased gene expression and their involvement in the physiological and pathological processes in human health and diseases.

Electron microscope mapping of the pericentric and intercalary heterochromatic regions of the polytene chromosomes of the mutant Suppressor of underreplication in Drosophila melanogaster.

PubMed

Semeshin, F; Belyaeva, S; Zhimulev, F

2001-12-01

Breaks and ectopic contacts in the heterochromatic regions of Drosophila melanogaster polytene chromosomes are the manifestations of the cytological effects of DNA underreplication. Their appearance makes these regions difficult to map. The Su(UR)ES gene, which controls the phenomenon, has been described recently. Mutation of this locus gives rise to new blocks of material in the pericentric heterochromatic regions and causes the disappearance of breaks and ectopic contacts in the intercalary heterochromatic regions, thereby making the banding pattern distinct and providing better opportunities for mapping of the heterochromatic regions in polytene chromosomes. Here, we present the results of an electron microscope study of the heterochromatic regions. In the wild-type salivary glands, the pericentric regions correspond to the beta-heterochromatin and do not show the banding pattern. The most conspicuous cytological effect of the Su(UR)ES mutation is the formation of a large banded chromosome fragment comprising at least 25 bands at the site where the 3L and 3R proximal arms connect. In the other pericentric regions, 20CF, 40BF and 41BC, 15, 12 and 9 new bands were revealed, respectively. A large block of densely packed material appears in the most proximal part of the fourth chromosome. An electron microscope analysis of 26 polytene chromosome regions showing the characteristic features of intercalary heterochromatin was also performed. Suppression of DNA underreplication in the mutant transforms the bands with weak spots into large single bands.

Recombination changes at the boundaries of fully and partially sex-linked regions between closely related Silene species pairs

PubMed Central

Campos, J L; Qiu, S; Guirao-Rico, S; Bergero, R; Charlesworth, D

2017-01-01

The establishment of a region of suppressed recombination is a critical change during sex chromosome evolution, leading to such properties as Y (and W) chromosome genetic degeneration, accumulation of repetitive sequences and heteromorphism. Although chromosome inversions can cause large regions to have suppressed recombination, and inversions are sometimes involved in sex chromosome evolution, gradual expansion of the non-recombining region could potentially sometimes occur. We here test whether closer linkage has recently evolved between the sex-determining region and several genes that are partially sex-linked in Silene latifolia, using Silene dioica, a closely related dioecious plants whose XY sex chromosome system is inherited from a common ancestor. The S. latifolia pseudoautosomal region (PAR) includes several genes extremely closely linked to the fully Y-linked region. These genes were added to an ancestral PAR of the sex chromosome pair in two distinct events probably involving translocations of autosomal genome regions causing multiple genes to become partially sex-linked. Close linkage with the PAR boundary must have evolved since these additions, because some genes added in both events now show almost complete sex linkage in S. latifolia. We compared diversity patterns of five such S. latifolia PAR boundary genes with their orthologues in S. dioica, including all three regions of the PAR (one gene that was in the ancestral PAR and two from each of the added regions). The results suggest recent recombination suppression in S. latifolia, since its split from S. dioica. PMID:27827389

The Cohesion Protein SOLO Associates with SMC1 and Is Required for Synapsis, Recombination, Homolog Bias and Cohesion and Pairing of Centromeres in Drosophila Meiosis

PubMed Central

Yan, Rihui; McKee, Bruce D.

2013-01-01

Cohesion between sister chromatids is mediated by cohesin and is essential for proper meiotic segregation of both sister chromatids and homologs. solo encodes a Drosophila meiosis-specific cohesion protein with no apparent sequence homology to cohesins that is required in male meiosis for centromere cohesion, proper orientation of sister centromeres and centromere enrichment of the cohesin subunit SMC1. In this study, we show that solo is involved in multiple aspects of meiosis in female Drosophila. Null mutations in solo caused the following phenotypes: 1) high frequencies of homolog and sister chromatid nondisjunction (NDJ) and sharply reduced frequencies of homolog exchange; 2) reduced transmission of a ring-X chromosome, an indicator of elevated frequencies of sister chromatid exchange (SCE); 3) premature loss of centromere pairing and cohesion during prophase I, as indicated by elevated foci counts of the centromere protein CID; 4) instability of the lateral elements (LE)s and central regions of synaptonemal complexes (SCs), as indicated by fragmented and spotty staining of the chromosome core/LE component SMC1 and the transverse filament protein C(3)G, respectively, at all stages of pachytene. SOLO and SMC1 are both enriched on centromeres throughout prophase I, co-align along the lateral elements of SCs and reciprocally co-immunoprecipitate from ovarian protein extracts. Our studies demonstrate that SOLO is closely associated with meiotic cohesin and required both for enrichment of cohesin on centromeres and stable assembly of cohesin into chromosome cores. These events underlie and are required for stable cohesion of centromeres, synapsis of homologous chromosomes, and a recombination mechanism that suppresses SCE to preferentially generate homolog crossovers (homolog bias). We propose that SOLO is a subunit of a specialized meiotic cohesin complex that mediates both centromeric and axial arm cohesion and promotes homolog bias as a component of chromosome cores. PMID:23874232

The cohesion protein SOLO associates with SMC1 and is required for synapsis, recombination, homolog bias and cohesion and pairing of centromeres in Drosophila Meiosis.

PubMed

Yan, Rihui; McKee, Bruce D

2013-01-01

Cohesion between sister chromatids is mediated by cohesin and is essential for proper meiotic segregation of both sister chromatids and homologs. solo encodes a Drosophila meiosis-specific cohesion protein with no apparent sequence homology to cohesins that is required in male meiosis for centromere cohesion, proper orientation of sister centromeres and centromere enrichment of the cohesin subunit SMC1. In this study, we show that solo is involved in multiple aspects of meiosis in female Drosophila. Null mutations in solo caused the following phenotypes: 1) high frequencies of homolog and sister chromatid nondisjunction (NDJ) and sharply reduced frequencies of homolog exchange; 2) reduced transmission of a ring-X chromosome, an indicator of elevated frequencies of sister chromatid exchange (SCE); 3) premature loss of centromere pairing and cohesion during prophase I, as indicated by elevated foci counts of the centromere protein CID; 4) instability of the lateral elements (LE)s and central regions of synaptonemal complexes (SCs), as indicated by fragmented and spotty staining of the chromosome core/LE component SMC1 and the transverse filament protein C(3)G, respectively, at all stages of pachytene. SOLO and SMC1 are both enriched on centromeres throughout prophase I, co-align along the lateral elements of SCs and reciprocally co-immunoprecipitate from ovarian protein extracts. Our studies demonstrate that SOLO is closely associated with meiotic cohesin and required both for enrichment of cohesin on centromeres and stable assembly of cohesin into chromosome cores. These events underlie and are required for stable cohesion of centromeres, synapsis of homologous chromosomes, and a recombination mechanism that suppresses SCE to preferentially generate homolog crossovers (homolog bias). We propose that SOLO is a subunit of a specialized meiotic cohesin complex that mediates both centromeric and axial arm cohesion and promotes homolog bias as a component of chromosome cores.

Mechanisms of Surface Antigenic Variation in the Human Pathogenic Fungus Pneumocystis jirovecii.

PubMed

Schmid-Siegert, Emanuel; Richard, Sophie; Luraschi, Amanda; Mühlethaler, Konrad; Pagni, Marco; Hauser, Philippe M

2017-11-07

Microbial pathogens commonly escape the human immune system by varying surface proteins. We investigated the mechanisms used for that purpose by Pneumocystis jirovecii This uncultivable fungus is an obligate pulmonary pathogen that in immunocompromised individuals causes pneumonia, a major life-threatening infection. Long-read PacBio sequencing was used to assemble a core of subtelomeres of a single P. jirovecii strain from a bronchoalveolar lavage fluid specimen from a single patient. A total of 113 genes encoding surface proteins were identified, including 28 pseudogenes. These genes formed a subtelomeric gene superfamily, which included five families encoding adhesive glycosylphosphatidylinositol (GPI)-anchored glycoproteins and one family encoding excreted glycoproteins. Numerical analyses suggested that diversification of the glycoproteins relies on mosaic genes created by ectopic recombination and occurs only within each family. DNA motifs suggested that all genes are expressed independently, except those of the family encoding the most abundant surface glycoproteins, which are subject to mutually exclusive expression. PCR analyses showed that exchange of the expressed gene of the latter family occurs frequently, possibly favored by the location of the genes proximal to the telomere because this allows concomitant telomere exchange. Our observations suggest that (i) the P. jirovecii cell surface is made of a complex mixture of different surface proteins, with a majority of a single isoform of the most abundant glycoprotein, (ii) genetic mosaicism within each family ensures variation of the glycoproteins, and (iii) the strategy of the fungus consists of the continuous production of new subpopulations composed of cells that are antigenically different. IMPORTANCE Pneumocystis jirovecii is a fungus causing severe pneumonia in immunocompromised individuals. It is the second most frequent life-threatening invasive fungal infection. We have studied the mechanisms of antigenic variation used by this pathogen to escape the human immune system, a strategy commonly used by pathogenic microorganisms. Using a new DNA sequencing technology generating long reads, we could characterize the highly repetitive gene families encoding the proteins that are present on the cellular surface of this pest. These gene families are localized in the regions close to the ends of all chromosomes, the subtelomeres. Such chromosomal localization was found to favor genetic recombinations between members of each gene family and to allow diversification of these proteins continuously over time. This pathogen seems to use a strategy of antigenic variation consisting of the continuous production of new subpopulations composed of cells that are antigenically different. Such a strategy is unique among human pathogens. Copyright © 2017 Schmid-Siegert et al.

Transposable elements in fish chromosomes: a study in the marine cobia species.

PubMed

Costa, G W W F; Cioffi, M B; Bertollo, L A C; Molina, W F

2013-01-01

Rachycentron canadum, a unique representative of the Rachycentridae family, has been the subject of considerable biotechnological interest due to its potential use in marine fish farming. This species has undergone extensive research concerning the location of genes and multigene families on its chromosomes. Although most of the genome of some organisms is composed of repeated DNA sequences, aspects of the origin and dispersion of these elements are still largely unknown. The physical mapping of repetitive sequences on the chromosomes of R. canadum proved to be relevant for evolutionary and applied purposes. Therefore, here, we present the mapping by fluorescence in situ hybridization of the transposable element (TE) Tol2, the non-LTR retrotransposons Rex1 and Rex3, together with the 18S and 5S rRNA genes in the chromosome of this species. The Tol2 TE, belonging to the family of hAT transposons, is homogeneously distributed in the euchromatic regions of the chromosomes but with huge colocalization with the 18S rDNA sites. The hybridization signals for Rex1 and Rex3 revealed a semi-arbitrary distribution pattern, presenting differentiated dispersion in euchromatic and heterochromatic regions. Rex1 elements are associated preferentially in heterochromatic regions, while Rex3 shows a scarce distribution in the euchromatic regions of the chromosomes. The colocalization of TEs with 18S and 5S rDNA revealed complex chromosomal regions of repetitive sequences. In addition, the nonpreferential distribution of Rex1 and Rex3 in all heterochromatic regions, as well as the preferential distribution of the Tol2 transposon associated with 18S rDNA sequences, reveals a distinct pattern of organization of TEs in the genome of this species. A heterogeneous chromosomal colonization of TEs may confer different evolutionary rates to the heterochromatic regions of this species.

Characterization of genetic sequence variation of 58 STR loci in four major population groups.

PubMed

Novroski, Nicole M M; King, Jonathan L; Churchill, Jennifer D; Seah, Lay Hong; Budowle, Bruce

2016-11-01

Massively parallel sequencing (MPS) can identify sequence variation within short tandem repeat (STR) alleles as well as their nominal allele lengths that traditionally have been obtained by capillary electrophoresis. Using the MiSeq FGx Forensic Genomics System (Illumina), STRait Razor, and in-house excel workbooks, genetic variation was characterized within STR repeat and flanking regions of 27 autosomal, 7 X-chromosome and 24 Y-chromosome STR markers in 777 unrelated individuals from four population groups. Seven hundred and forty six autosomal, 227 X-chromosome, and 324 Y-chromosome STR alleles were identified by sequence compared with 357 autosomal, 107 X-chromosome, and 189 Y-chromosome STR alleles that were identified by length. Within the observed sequence variation, 227 autosomal, 156 X-chromosome, and 112 Y-chromosome novel alleles were identified and described. One hundred and seventy six autosomal, 123 X-chromosome, and 93 Y-chromosome sequence variants resided within STR repeat regions, and 86 autosomal, 39 X-chromosome, and 20 Y-chromosome variants were located in STR flanking regions. Three markers, D18S51, DXS10135, and DYS385a-b had 1, 4, and 1 alleles, respectively, which contained both a novel repeat region variant and a flanking sequence variant in the same nucleotide sequence. There were 50 markers that demonstrated a relative increase in diversity with the variant sequence alleles compared with those of traditional nominal length alleles. These population data illustrate the genetic variation that exists in the commonly used STR markers in the selected population samples and provide allele frequencies for statistical calculations related to STR profiling with MPS data. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Characterization of a rice variety with high hydraulic conductance and identification of the chromosome region responsible using chromosome segment substitution lines

PubMed Central

Adachi, Shunsuke; Tsuru, Yukiko; Kondo, Motohiko; Yamamoto, Toshio; Arai-Sanoh, Yumiko; Ando, Tsuyu; Ookawa, Taiichiro; Yano, Masahiro; Hirasawa, Tadashi

2010-01-01

Background and Aims The rate of photosynthesis in paddy rice often decreases at noon on sunny days because of water stress, even under submerged conditions. Maintenance of higher rates of photosynthesis during the day might improve both yield and dry matter production in paddy rice. A high-yielding indica variety, ‘Habataki’, maintains a high rate of leaf photosynthesis during the daytime because of the higher hydraulic conductance from roots to leaves than in the standard japonica variety ‘Sasanishiki’. This research was conducted to characterize the trait responsible for the higher hydraulic conductance in ‘Habataki’ and identified a chromosome region for the high hydraulic conductance. Methods Hydraulic conductance to passive water transport and to osmotic water transport was determined for plants under intense transpiration and for plants without transpiration, respectively. The varietal difference in hydraulic conductance was examined with respect to root surface area and hydraulic conductivity (hydraulic conductance per root surface area, Lp). To identify the chromosome region responsible for higher hydraulic conductance, chromosome segment substitution lines (CSSLs) derived from a cross between ‘Sasanishiki’ and ‘Habataki’ were used. Key Results The significantly higher hydraulic conductance resulted from the larger root surface area not from Lp in ‘Habataki’. A chromosome region associated with the elevated hydraulic conductance was detected between RM3916 and RM2431 on the long arm of chromosome 4. The CSSL, in which this region was substituted with the ‘Habataki’ chromosome segment in the ‘Sasanishiki’ background, had a larger root mass than ‘Sasanishiki’. Conclusions The trait for increasing plant hydraulic conductance and, therefore, maintaining the higher rate of leaf photosynthesis under the conditions of intense transpiration in ‘Habataki’ was identified, and it was estimated that there is at least one chromosome region for the trait located on chromosome 4. PMID:20810742

The Coordinated Positive Regulation of Topoisomerase Genes Maintains Topological Homeostasis in Streptomyces coelicolor

PubMed Central

Gongerowska, Martyna; Gutkowski, Paweł; Zakrzewska-Czerwińska, Jolanta; Jakimowicz, Dagmara

2016-01-01

ABSTRACT Maintaining an optimal level of chromosomal supercoiling is critical for the progression of DNA replication and transcription. Moreover, changes in global supercoiling affect the expression of a large number of genes and play a fundamental role in adapting to stress. Topoisomerase I (TopA) and gyrase are key players in the regulation of bacterial chromosomal topology through their respective abilities to relax and compact DNA. Soil bacteria such as Streptomyces species, which grow as branched, multigenomic hyphae, are subject to environmental stresses that are associated with changes in chromosomal topology. The topological fluctuations modulate the transcriptional activity of a large number of genes and in Streptomyces are related to the production of antibiotics. To better understand the regulation of topological homeostasis in Streptomyces coelicolor, we investigated the interplay between the activities of the topoisomerase-encoding genes topA and gyrBA. We show that the expression of both genes is supercoiling sensitive. Remarkably, increased chromosomal supercoiling induces the topA promoter but only slightly influences gyrBA transcription, while DNA relaxation affects the topA promoter only marginally but strongly activates the gyrBA operon. Moreover, we showed that exposure to elevated temperatures induces rapid relaxation, which results in changes in the levels of both topoisomerases. We therefore propose a unique mechanism of S. coelicolor chromosomal topology maintenance based on the supercoiling-dependent stimulation, rather than repression, of the transcription of both topoisomerase genes. These findings provide important insight into the maintenance of topological homeostasis in an industrially important antibiotic producer. IMPORTANCE We describe the unique regulation of genes encoding two topoisomerases, topoisomerase I (TopA) and gyrase, in a model Streptomyces species. Our studies demonstrate the coordination of topoisomerase gene regulation, which is crucial for maintenance of topological homeostasis. Streptomyces species are producers of a plethora of biologically active secondary metabolites, including antibiotics, antitumor agents, and immunosuppressants. The significant regulatory factor controlling the secondary metabolism is the global chromosomal topology. Thus, the investigation of chromosomal topology homeostasis in Streptomyces strains is crucial for their use in industrial applications as producers of secondary metabolites. PMID:27551021

Imputation and subset-based association analysis across different cancer types identifies multiple independent risk loci in the TERT-CLPTM1L region on chromosome 5p15.33.

PubMed

Wang, Zhaoming; Zhu, Bin; Zhang, Mingfeng; Parikh, Hemang; Jia, Jinping; Chung, Charles C; Sampson, Joshua N; Hoskins, Jason W; Hutchinson, Amy; Burdette, Laurie; Ibrahim, Abdisamad; Hautman, Christopher; Raj, Preethi S; Abnet, Christian C; Adjei, Andrew A; Ahlbom, Anders; Albanes, Demetrius; Allen, Naomi E; Ambrosone, Christine B; Aldrich, Melinda; Amiano, Pilar; Amos, Christopher; Andersson, Ulrika; Andriole, Gerald; Andrulis, Irene L; Arici, Cecilia; Arslan, Alan A; Austin, Melissa A; Baris, Dalsu; Barkauskas, Donald A; Bassig, Bryan A; Beane Freeman, Laura E; Berg, Christine D; Berndt, Sonja I; Bertazzi, Pier Alberto; Biritwum, Richard B; Black, Amanda; Blot, William; Boeing, Heiner; Boffetta, Paolo; Bolton, Kelly; Boutron-Ruault, Marie-Christine; Bracci, Paige M; Brennan, Paul; Brinton, Louise A; Brotzman, Michelle; Bueno-de-Mesquita, H Bas; Buring, Julie E; Butler, Mary Ann; Cai, Qiuyin; Cancel-Tassin, Geraldine; Canzian, Federico; Cao, Guangwen; Caporaso, Neil E; Carrato, Alfredo; Carreon, Tania; Carta, Angela; Chang, Gee-Chen; Chang, I-Shou; Chang-Claude, Jenny; Che, Xu; Chen, Chien-Jen; Chen, Chih-Yi; Chen, Chung-Hsing; Chen, Constance; Chen, Kuan-Yu; Chen, Yuh-Min; Chokkalingam, Anand P; Chu, Lisa W; Clavel-Chapelon, Francoise; Colditz, Graham A; Colt, Joanne S; Conti, David; Cook, Michael B; Cortessis, Victoria K; Crawford, E David; Cussenot, Olivier; Davis, Faith G; De Vivo, Immaculata; Deng, Xiang; Ding, Ti; Dinney, Colin P; Di Stefano, Anna Luisa; Diver, W Ryan; Duell, Eric J; Elena, Joanne W; Fan, Jin-Hu; Feigelson, Heather Spencer; Feychting, Maria; Figueroa, Jonine D; Flanagan, Adrienne M; Fraumeni, Joseph F; Freedman, Neal D; Fridley, Brooke L; Fuchs, Charles S; Gago-Dominguez, Manuela; Gallinger, Steven; Gao, Yu-Tang; Gapstur, Susan M; Garcia-Closas, Montserrat; Garcia-Closas, Reina; Gastier-Foster, Julie M; Gaziano, J Michael; Gerhard, Daniela S; Giffen, Carol A; Giles, Graham G; Gillanders, Elizabeth M; Giovannucci, Edward L; Goggins, Michael; Gokgoz, Nalan; Goldstein, Alisa M; Gonzalez, Carlos; Gorlick, Richard; Greene, Mark H; Gross, Myron; Grossman, H Barton; Grubb, Robert; Gu, Jian; Guan, Peng; Haiman, Christopher A; Hallmans, Goran; Hankinson, Susan E; Harris, Curtis C; Hartge, Patricia; Hattinger, Claudia; Hayes, Richard B; He, Qincheng; Helman, Lee; Henderson, Brian E; Henriksson, Roger; Hoffman-Bolton, Judith; Hohensee, Chancellor; Holly, Elizabeth A; Hong, Yun-Chul; Hoover, Robert N; Hosgood, H Dean; Hsiao, Chin-Fu; Hsing, Ann W; Hsiung, Chao Agnes; Hu, Nan; Hu, Wei; Hu, Zhibin; Huang, Ming-Shyan; Hunter, David J; Inskip, Peter D; Ito, Hidemi; Jacobs, Eric J; Jacobs, Kevin B; Jenab, Mazda; Ji, Bu-Tian; Johansen, Christoffer; Johansson, Mattias; Johnson, Alison; Kaaks, Rudolf; Kamat, Ashish M; Kamineni, Aruna; Karagas, Margaret; Khanna, Chand; Khaw, Kay-Tee; Kim, Christopher; Kim, In-Sam; Kim, Jin Hee; Kim, Yeul Hong; Kim, Young-Chul; Kim, Young Tae; Kang, Chang Hyun; Jung, Yoo Jin; Kitahara, Cari M; Klein, Alison P; Klein, Robert; Kogevinas, Manolis; Koh, Woon-Puay; Kohno, Takashi; Kolonel, Laurence N; Kooperberg, Charles; Kratz, Christian P; Krogh, Vittorio; Kunitoh, Hideo; Kurtz, Robert C; Kurucu, Nilgun; Lan, Qing; Lathrop, Mark; Lau, Ching C; Lecanda, Fernando; Lee, Kyoung-Mu; Lee, Maxwell P; Le Marchand, Loic; Lerner, Seth P; Li, Donghui; Liao, Linda M; Lim, Wei-Yen; Lin, Dongxin; Lin, Jie; Lindstrom, Sara; Linet, Martha S; Lissowska, Jolanta; Liu, Jianjun; Ljungberg, Börje; Lloreta, Josep; Lu, Daru; Ma, Jing; Malats, Nuria; Mannisto, Satu; Marina, Neyssa; Mastrangelo, Giuseppe; Matsuo, Keitaro; McGlynn, Katherine A; McKean-Cowdin, Roberta; McNeill, Lorna H; McWilliams, Robert R; Melin, Beatrice S; Meltzer, Paul S; Mensah, James E; Miao, Xiaoping; Michaud, Dominique S; Mondul, Alison M; Moore, Lee E; Muir, Kenneth; Niwa, Shelley; Olson, Sara H; Orr, Nick; Panico, Salvatore; Park, Jae Yong; Patel, Alpa V; Patino-Garcia, Ana; Pavanello, Sofia; Peeters, Petra H M; Peplonska, Beata; Peters, Ulrike; Petersen, Gloria M; Picci, Piero; Pike, Malcolm C; Porru, Stefano; Prescott, Jennifer; Pu, Xia; Purdue, Mark P; Qiao, You-Lin; Rajaraman, Preetha; Riboli, Elio; Risch, Harvey A; Rodabough, Rebecca J; Rothman, Nathaniel; Ruder, Avima M; Ryu, Jeong-Seon; Sanson, Marc; Schned, Alan; Schumacher, Fredrick R; Schwartz, Ann G; Schwartz, Kendra L; Schwenn, Molly; Scotlandi, Katia; Seow, Adeline; Serra, Consol; Serra, Massimo; Sesso, Howard D; Severi, Gianluca; Shen, Hongbing; Shen, Min; Shete, Sanjay; Shiraishi, Kouya; Shu, Xiao-Ou; Siddiq, Afshan; Sierrasesumaga, Luis; Sierri, Sabina; Loon Sihoe, Alan Dart; Silverman, Debra T; Simon, Matthias; Southey, Melissa C; Spector, Logan; Spitz, Margaret; Stampfer, Meir; Stattin, Par; Stern, Mariana C; Stevens, Victoria L; Stolzenberg-Solomon, Rachael Z; Stram, Daniel O; Strom, Sara S; Su, Wu-Chou; Sund, Malin; Sung, Sook Whan; Swerdlow, Anthony; Tan, Wen; Tanaka, Hideo; Tang, Wei; Tang, Ze-Zhang; Tardon, Adonina; Tay, Evelyn; Taylor, Philip R; Tettey, Yao; Thomas, David M; Tirabosco, Roberto; Tjonneland, Anne; Tobias, Geoffrey S; Toro, Jorge R; Travis, Ruth C; Trichopoulos, Dimitrios; Troisi, Rebecca; Truelove, Ann; Tsai, Ying-Huang; Tucker, Margaret A; Tumino, Rosario; Van Den Berg, David; Van Den Eeden, Stephen K; Vermeulen, Roel; Vineis, Paolo; Visvanathan, Kala; Vogel, Ulla; Wang, Chaoyu; Wang, Chengfeng; Wang, Junwen; Wang, Sophia S; Weiderpass, Elisabete; Weinstein, Stephanie J; Wentzensen, Nicolas; Wheeler, William; White, Emily; Wiencke, John K; Wolk, Alicja; Wolpin, Brian M; Wong, Maria Pik; Wrensch, Margaret; Wu, Chen; Wu, Tangchun; Wu, Xifeng; Wu, Yi-Long; Wunder, Jay S; Xiang, Yong-Bing; Xu, Jun; Yang, Hannah P; Yang, Pan-Chyr; Yatabe, Yasushi; Ye, Yuanqing; Yeboah, Edward D; Yin, Zhihua; Ying, Chen; Yu, Chong-Jen; Yu, Kai; Yuan, Jian-Min; Zanetti, Krista A; Zeleniuch-Jacquotte, Anne; Zheng, Wei; Zhou, Baosen; Mirabello, Lisa; Savage, Sharon A; Kraft, Peter; Chanock, Stephen J; Yeager, Meredith; Landi, Maria Terese; Shi, Jianxin; Chatterjee, Nilanjan; Amundadottir, Laufey T

2014-12-15

Genome-wide association studies (GWAS) have mapped risk alleles for at least 10 distinct cancers to a small region of 63 000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (association analysis based on subsets) across six distinct cancers in 34 248 cases and 45 036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single-nucleotide polymorphisms: five in the TERT gene (Region 1: rs7726159, P = 2.10 × 10(-39); Region 3: rs2853677, P = 3.30 × 10(-36) and PConditional = 2.36 × 10(-8); Region 4: rs2736098, P = 3.87 × 10(-12) and PConditional = 5.19 × 10(-6), Region 5: rs13172201, P = 0.041 and PConditional = 2.04 × 10(-6); and Region 6: rs10069690, P = 7.49 × 10(-15) and PConditional = 5.35 × 10(-7)) and one in the neighboring CLPTM1L gene (Region 2: rs451360; P = 1.90 × 10(-18) and PConditional = 7.06 × 10(-16)). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele-specific effects on DNA methylation were seen for a subset of risk loci, indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci. Published by Oxford University Press 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

The role of MatP, ZapA and ZapB in chromosomal organization and dynamics in Escherichia coli

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

Mannik, Jaana; Castillo, Daniel E.; Yang, Da

Despite extensive research over several decades, a comprehensive view of how the Escherichia coli chromosome is organized within the nucleoid, and how two daughter chromosomes segregate has yet to emerge. Here we investigate the role of the MatP, ZapA and ZapB proteins in organizing the replication terminus (Ter) region and in the chromosomal segregation process. Quantitative image analysis of the fluorescently labeled Ter region shows that the replication terminus attaches to the divisome in a single segment along the perimeter of the cell in a MatP, ZapA and ZapB-dependent manner. The attachment does not significantly affect the bulk chromosome segregationmore » in slow growth conditions. With or without the attachment, two chromosomal masses separate from each other at a speed comparable to the cell growth. The separation starts even before the replication terminus region positions itself at the center of the nucleoid. Modeling of the segregation based on conformational entropy correctly predicts the positioning of the replication terminus region within the nucleoid. Furthermore, the model produces a distinctly different chromosomal density distribution than the experiment, indicating that the conformational entropy plays a limited role in segregating the chromosomes in the late stages of replication.« less

The role of MatP, ZapA and ZapB in chromosomal organization and dynamics in Escherichia coli

DOE PAGES

Mannik, Jaana; Castillo, Daniel E.; Yang, Da; ...

2016-01-13

Despite extensive research over several decades, a comprehensive view of how the Escherichia coli chromosome is organized within the nucleoid, and how two daughter chromosomes segregate has yet to emerge. Here we investigate the role of the MatP, ZapA and ZapB proteins in organizing the replication terminus (Ter) region and in the chromosomal segregation process. Quantitative image analysis of the fluorescently labeled Ter region shows that the replication terminus attaches to the divisome in a single segment along the perimeter of the cell in a MatP, ZapA and ZapB-dependent manner. The attachment does not significantly affect the bulk chromosome segregationmore » in slow growth conditions. With or without the attachment, two chromosomal masses separate from each other at a speed comparable to the cell growth. The separation starts even before the replication terminus region positions itself at the center of the nucleoid. Modeling of the segregation based on conformational entropy correctly predicts the positioning of the replication terminus region within the nucleoid. Furthermore, the model produces a distinctly different chromosomal density distribution than the experiment, indicating that the conformational entropy plays a limited role in segregating the chromosomes in the late stages of replication.« less

Polymer modeling of the E. coli genome reveals the involvement of locus positioning and macrodomain structuring for the control of chromosome conformation and segregation

PubMed Central

Junier, Ivan; Boccard, Frédéric; Espéli, Olivier

2014-01-01

The mechanisms that control chromosome conformation and segregation in bacteria have not yet been elucidated. In Escherichia coli, the mere presence of an active process remains an open question. Here, we investigate the conformation and segregation pattern of the E. coli genome by performing numerical simulations on a polymer model of the chromosome. We analyze the roles of the intrinsic structuring of chromosomes and the forced localization of specific loci, which are observed in vivo. Specifically, we examine the segregation pattern of a chromosome that is divided into four structured macrodomains (MDs) and two non-structured regions. We find that strong osmotic-like organizational forces, which stem from the differential condensation levels of the chromosome regions, dictate the cellular disposition of the chromosome. Strikingly, the comparison of our in silico results with fluorescent imaging of the chromosome choreography in vivo reveals that in the presence of MDs the targeting of the origin and terminus regions to specific positions are sufficient to generate a segregation pattern that is indistinguishable from experimentally observed patterns. PMID:24194594

Identification of chromosome 7 inversion breakpoints in an autistic family narrows candidate region for autism susceptibility.

PubMed

Cukier, Holly N; Skaar, David A; Rayner-Evans, Melissa Y; Konidari, Ioanna; Whitehead, Patrice L; Jaworski, James M; Cuccaro, Michael L; Pericak-Vance, Margaret A; Gilbert, John R

2009-10-01

Chromosomal breaks and rearrangements have been observed in conjunction with autism and autistic spectrum disorders. A chromosomal inversion has been previously reported in autistic siblings, spanning the region from approximately 7q22.1 to 7q31. This family is distinguished by having multiple individuals with autism and associated disabilities. The region containing the inversion has been strongly implicated in autism by multiple linkage studies, and has been particularly associated with language defects in autism as well as in other disorders with language components. Mapping of the inversion breakpoints by FISH has localized the inversion to the region spanning approximately 99-108.75 Mb of chromosome 7. The proximal breakpoint has the potential to disrupt either the coding sequence or regulatory regions of a number of cytochrome P450 genes while the distal region falls in a relative gene desert. Copy number variant analysis of the breakpoint regions detected no duplication or deletion that could clearly be associated with disease status. Association analysis in our autism data set using single nucleotide polymorphisms located near the breakpoints showed no significant association with proximal breakpoint markers, but has identified markers near the distal breakpoint ( approximately 108-110 Mb) with significant associations to autism. The chromosomal abnormality in this family strengthens the case for an autism susceptibility gene in the chromosome 7q22-31 region and targets a candidate region for further investigation.

Fabry disease: Evidence for a regional founder effect of the GLA gene mutation 30delG in Brazilian patients.

PubMed

de Alencar, Dayse Oliveira; Netto, Cristina; Ashton-Prolla, Patricia; Giugliani, Roberto; Ribeiro-Dos-Santos, Ândrea; Pereira, Fernanda; Matte, Ursula; Santos, Ney; Santos, Sidney

2014-01-01

The Fabry disease is caused by mutations in the gene ( GLA ) that encodes the enzyme α-galactosidase A (α-Gal A). More than 500 pathologic variants of GLA have already been described, most of them are family-specific. In southern Brazil, a frequent single-base deletion ( GLA 30delG) was identified among four families that do not recognize any common ancestral. In order to investigate the history of this mutation (investigate the founder effect, estimate the mutation age and the most likely source), six gene-flanking microsatellite markers of the X chromosome on the mutation carriers and their parents, 150 individuals from the same population and 300 individuals that compose the Brazilian parental populations (Europeans, Africans and Native Americans) were genotyped. A common haplotype to the four families was identified and characterized as founder. The age was estimated with two statistics software (DMLE 2.2 and ESTIAGE) that agreed with 11 to 12 generations old. This result indicates that the mutation GLA 30delG was originated from a single event on the X chromosome of a European immigrant, during the southern Brazil colonization between 1710 and 1740.

Localization of a putative transcriptional regulator (ATRX) at pericentromeric heterochromatin and the short arms of acrocentric chromosomes.

PubMed

McDowell, T L; Gibbons, R J; Sutherland, H; O'Rourke, D M; Bickmore, W A; Pombo, A; Turley, H; Gatter, K; Picketts, D J; Buckle, V J; Chapman, L; Rhodes, D; Higgs, D R

1999-11-23

ATRX is a member of the SNF2 family of helicase/ATPases that is thought to regulate gene expression via an effect on chromatin structure and/or function. Mutations in the hATRX gene cause severe syndromal mental retardation associated with alpha-thalassemia. Using indirect immunofluorescence and confocal microscopy we have shown that ATRX protein is associated with pericentromeric heterochromatin during interphase and mitosis. By coimmunofluorescence, ATRX localizes with a mouse homologue of the Drosophila heterochromatic protein HP1 in vivo, consistent with a previous two-hybrid screen identifying this interaction. From the analysis of a trap assay for nuclear proteins, we have shown that the localization of ATRX to heterochromatin is encoded by its N-terminal region, which contains a conserved plant homeodomain-like finger and a coiled-coil domain. In addition to its association with heterochromatin, at metaphase ATRX clearly binds to the short arms of human acrocentric chromosomes, where the arrays of ribosomal DNA are located. The unexpected association of a putative transcriptional regulator with highly repetitive DNA provides a potential explanation for the variability in phenotype of patients with identical mutations in the ATRX gene.

Increased dosage of DYRK1A and DSCR1 delays neuronal differentiation in neocortical progenitor cells

PubMed Central

Kurabayashi, Nobuhiro; Sanada, Kamon

2013-01-01

Down's syndrome (DS), a major genetic cause of mental retardation, arises from triplication of genes on human chromosome 21. Here we show that DYRK1A (dual-specificity tyrosine-phosphorylated and -regulated kinase 1A) and DSCR1 (DS critical region 1), two genes lying within human chromosome 21 and encoding for a serine/threonine kinase and calcineurin regulator, respectively, are expressed in neural progenitors in the mouse developing neocortex. Increasing the dosage of both proteins in neural progenitors leads to a delay in neuronal differentiation, resulting ultimately in alteration of their laminar fate. This defect is mediated by the cooperative actions of DYRK1A and DSCR1 in suppressing the activity of the transcription factor NFATc. In Ts1Cje mice, a DS mouse model, dysregulation of NFATc in conjunction with increased levels of DYRK1A and DSCR1 was observed. Furthermore, counteracting the dysregulated pathway ameliorates the delayed neuronal differentiation observed in Ts1Cje mice. In sum, our findings suggest that dosage of DYRK1A and DSCR1 is critical for proper neurogenesis through NFATc and provide a potential mechanism to explain the neurodevelopmental defects in DS. PMID:24352425

Progressive Recombination Suppression and Differentiation in Recently Evolved Neo-sex Chromosomes

PubMed Central

Natri, Heini M.; Shikano, Takahito; Merilä, Juha

2013-01-01

Recombination suppression leads to the structural and functional differentiation of sex chromosomes and is thus a crucial step in the process of sex chromosome evolution. Despite extensive theoretical work, the exact processes and mechanisms of recombination suppression and differentiation are not well understood. In threespine sticklebacks (Gasterosteus aculeatus), a different sex chromosome system has recently evolved by a fusion between the Y chromosome and an autosome in the Japan Sea lineage, which diverged from the ancestor of other lineages approximately 2 Ma. We investigated the evolutionary dynamics and differentiation processes of sex chromosomes based on comparative analyses of these divergent lineages using 63 microsatellite loci. Both chromosome-wide differentiation patterns and phylogenetic inferences with X and Y alleles indicated that the ancestral sex chromosomes were extensively differentiated before the divergence of these lineages. In contrast, genetic differentiation appeared to have proceeded only in a small region of the neo-sex chromosomes. The recombination maps constructed for the Japan Sea lineage indicated that recombination has been suppressed or reduced over a large region spanning the ancestral and neo-sex chromosomes. Chromosomal regions exhibiting genetic differentiation and suppressed or reduced recombination were detected continuously and sequentially in the neo-sex chromosomes, suggesting that differentiation has gradually spread from the fusion point following the extension of recombination suppression. Our study illustrates an ongoing process of sex chromosome differentiation, providing empirical support for the theoretical model postulating that recombination suppression and differentiation proceed in a gradual manner in the very early stage of sex chromosome evolution. PMID:23436913

Divergent Evolutionary Trajectories of Two Young, Homomorphic, and Closely Related Sex Chromosome Systems

PubMed Central

Furman, Benjamin L S; Evans, Ben J

2018-01-01

Abstract There exists extraordinary variation among species in the degree and nature of sex chromosome divergence. However, much of our knowledge about sex chromosomes is based on comparisons between deeply diverged species with different ancestral sex chromosomes, making it difficult to establish how fast and why sex chromosomes acquire variable levels of divergence. To address this problem, we studied sex chromosome evolution in two species of African clawed frog (Xenopus), both of whom acquired novel systems for sex determination from a recent common ancestor, and both of whom have female (ZW/ZZ) heterogamy. Derived sex chromosomes of one species, X. laevis, have a small region of suppressed recombination that surrounds the sex determining locus, and have remained this way for millions of years. In the other species, X. borealis, a younger sex chromosome system exists on a different pair of chromosomes, but the region of suppressed recombination surrounding an unidentified sex determining gene is vast, spanning almost half of the sex chromosomes. Differences between these sex chromosome systems are also apparent in the extent of nucleotide divergence between the sex chromosomes carried by females. Our analyses also indicate that in autosomes of both of these species, recombination during oogenesis occurs more frequently and in different genomic locations than during spermatogenesis. These results demonstrate that new sex chromosomes can assume radically different evolutionary trajectories, with far-reaching genomic consequences. They also suggest that in some instances the origin of new triggers for sex determination may be coupled with rapid evolution sex chromosomes, including recombination suppression of large genomic regions. PMID:29608717

The multiple sex chromosomes of platypus and echidna are not completely identical and several share homology with the avian Z.

PubMed

Rens, Willem; O'Brien, Patricia C M; Grützner, Frank; Clarke, Oliver; Graphodatskaya, Daria; Tsend-Ayush, Enkhjargal; Trifonov, Vladimir A; Skelton, Helen; Wallis, Mary C; Johnston, Steve; Veyrunes, Frederic; Graves, Jennifer A M; Ferguson-Smith, Malcolm A

2007-01-01

Sex-determining systems have evolved independently in vertebrates. Placental mammals and marsupials have an XY system, birds have a ZW system. Reptiles and amphibians have different systems, including temperature-dependent sex determination, and XY and ZW systems that differ in origin from birds and placental mammals. Monotremes diverged early in mammalian evolution, just after the mammalian clade diverged from the sauropsid clade. Our previous studies showed that male platypus has five X and five Y chromosomes, no SRY, and DMRT1 on an X chromosome. In order to investigate monotreme sex chromosome evolution, we performed a comparative study of platypus and echidna by chromosome painting and comparative gene mapping. Chromosome painting reveals a meiotic chain of nine sex chromosomes in the male echidna and establishes their order in the chain. Two of those differ from those in the platypus, three of the platypus sex chromosomes differ from those of the echidna and the order of several chromosomes is rearranged. Comparative gene mapping shows that, in addition to bird autosome regions, regions of bird Z chromosomes are homologous to regions in four platypus X chromosomes, that is, X1, X2, X3, X5, and in chromosome Y1. Monotreme sex chromosomes are easiest to explain on the hypothesis that autosomes were added sequentially to the translocation chain, with the final additions after platypus and echidna divergence. Genome sequencing and contig anchoring show no homology yet between platypus and therian Xs; thus, monotremes have a unique XY sex chromosome system that shares some homology with the avian Z.

Wide clinical variability in cat eye syndrome patients: four non-related patients and three patients from the same family.

PubMed

Belangero, S I; Pacanaro, A N X; Bellucco, F T; Christofolini, D M; Kulikowski, L D; Guilherme, R S; Bortolai, A; Dutra, A R N; Piazzon, F B; Cernach, M C; Melaragno, M I

2012-01-01

A small supernumerary marker chromosome (sSMC) derived from chromosome 22 is a relatively common cytogenetic finding. This sSMC typically results in tetrasomy for a chromosomal region that spans the chromosome 22p arm and the proximal 2 Mb of 22q11.21. Using classical cytogenetics, fluorescence in situ hybridization, multiplex ligation-dependent probe amplification, and array techniques, 7 patients with sSMCs derived from chromosome 22 were studied: 4 non-related and 3 from the same family (mother, daughter, and son). The sSMCs in all patients were dicentric and bisatellited chromosomes with breakpoints in the chromosome 22 low-copy repeat A region, resulting in cat eye syndrome (CES) due to chromosome 22 partial tetrasomy 22pter→q11.2 including the cat eye chromosome region. Although all subjects presented the same chromosomal abnormality, they showed a wide range of phenotypic differences, even in the 3 patients from the same family. There are no previous reports of CES occurring within 3 patients in the same family. Thus, the clinical and follow-up data presented here contribute to a better delineation of the phenotypes and outcomes of CES patients and will be useful for genetic counseling. Copyright © 2012 S. Karger AG, Basel.