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1

Resistance performances of transgenic bt rice lines T(2A)-1 and T1c-19 against Cnaphalocrocis medinalis (Lepidoptera: Pyralidae).  

PubMed

The transgenic Bacillus thuringiensis (Bt) rice, Oryza sativa L., lines T(2A)-1 and T1c-19 expressing Cry2A* and Cry1C* from 'Minhui 63' (MH63) were evaluated for resistance to newly hatched and third-instar larvae of Cnaphalocrocis medinalis (Lepidoptera: Pyralidae), by using detached leaf laboratory bioassays. Both T(2A)-1 and T1c-19 rice showed high C. medinalis resistance; however, the lethal time (LT)50 of larvae fed with T(2A)-1 rice was significantly longer than that of larvae fed with T1c-19 rice, implying T1c-19 rice was more toxic to C. medinalis larvae. Larval mortality after 4 d on nitrogen-free MH63 was 25.5% compared with 2.4% mortality on high nitrogen fertilizer (250 kg N/ha) plants. Larval mortality on high nitrogen T(2A)-1 plants declined by 20% compared with nitrogen-free plants. However, resistance in T1c-19 plants was unaffected by nitrogen fertilizer. C. medinalis moths preferred MH63 at both the seedling and grain milk stages for oviposition but not the T1c-19 and T(2A)-1 Bt rice lines. PMID:22066204

Zheng, Xusong; Yang, Yajun; Xu, Hongxing; Chen, Hao; Wang, Baoju; Lin, Yongjun; Lu, Zhongxian

2011-10-01

2

No Direct Effects of Two Transgenic Bt Rice Lines, T1C-19 and T2A-1, on the Arthropod Communities.  

PubMed

A 2-yr field trial was conducted to assess the impacts of two new transgenic Bt rice lines, T1C-19 expressing Cry1C protein and T2A-1 expressing Cry2A protein, on the arthropod community sampled via vacuum. All the arthropods were classified into five guilds, including herbivores, parasitoids, predators, detritivores, and others. The seasonal density and dominance distribution of each guild and community-level indices (species richness, Shannon-Wiener diversity index, Simpson diversity index, and evenness index) were compared among rice types. Principal response curves were used to investigate the differences of entire arthropod community of Bt rice plots relative to non-Bt rice plots. The results showed no significant difference was detected in the community-level indices and dominance distribution of guilds between Bt and non-Bt rice plots. The seasonal density of herbivores, detritivores, and others as well as density of the arthropod overall community were also not significantly affected by rice types in either year, although the density of predators and parasitoids in Bt rice plots was significantly lower than those in non-Bt rice plots. The lower abundances of Braconidae, Eulophidae, Cyrtorhinus lividipennis (Reuter) (Hemiptera: Miridae), and Theridiidae in Bt rice plots are likely attributed to the lower abundances of prey species or hosts. Principal response curves revealed that arthropod community in Bt was similar with that in non-Bt rice plots. In conclusion, our findings indicate that these two tested Bt rice lines had no marked negative effects on the arthropod community in the paddy fields. PMID:25203669

Lu, Z B; Tian, J C; Han, N S; Hu, C; Peng, Y F; Stanley, David; Ye, G Y

2014-10-01

3

Interhospital CT image communication: T-1 line versus courier service  

NASA Astrophysics Data System (ADS)

The Mount Zion Hospital (MZH) in San Francisco, Calif. is associated with the University of California at San Francisco (UCSF) medical center. These hospitals are approximately two miles apart. The UCSF radiology department supports specialty image reading for MZH daily. The major issue involved with this service is the access of patient images. Currently, the patient image access is through two ways: (1) inter-hospital travel, and (2) image delivery. Both methods are neither efficient nor economic. If patient images can be transferred from MZH to UCSF to be viewed in digital form in a reasonable time period, the issue of patient image accession can be resolved. This study attempts to use an available digital communication technology, a T-1 line, to verify this hypothesis. The study is centered on the comparison between the T-1 line and courier service with respect to cost and image delivery performance. This comparison study focuses on CT images with an emphasis on neuroradiology application.

Lou, Shyhliang A.; Huang, H. K.; Bazzill, Todd M.; Gould, Robert G.; Dillon, William P.; Schomer, Barbara G.

1995-05-01

4

Abstract Transgene loci in 16 transgenic oat (Avena sativa L.) lines produced by microprojectile bombard-  

E-print Network

Abstract Transgene loci in 16 transgenic oat (Avena sativa L.) lines produced by microprojectile transgene loci and 8 lines had 2 or 3 loci. Double FISH of the transgene and oat C- and A heterochromatic C ge- nome and the A/D genomes of hexaploid oat, nor among chromosomes within the genomes

Pawlowski, Wojtek

5

[Obtaining the transgenic lines of finger millet Eleusine coracana (L.) Gaertn. With dinitroaniline resistance].  

PubMed

The current data is dedicated to the study of bioballistic and Agrobacterium-mediated transformation of finger millet with the constructs carrying the mutant alpha-tubulin gene (TUAm 1), isolated from R-biotype goosegrass (Eleusine indica L.), for the decision of problem of dinitroaniline-resistance. It was found that 10 microM of trifluralin is optimal for the selection of transgene plants of finger millet. PCR analysis of transformed lines confirmed the transgene nature of plants. The analysis of seed of T1 oftransgene lines confirmed heterozygous character of inheritance of the resistance. PMID:25016822

Baer, G Ia; Emets, A I; Blium, Ia B

2014-01-01

6

Development of stem borer resistant transgenic parental lines involved in the production of hybrid rice.  

PubMed

Stem borer resistant transgenic parental lines, involved in hybrid rice, were produced by Agrobacterium-mediated gene transfer method. Two pSB111 super-binary vectors containing modified cry1Ab/cry1Ac genes driven by maize ubiquitin promoter, and herbicide resistance gene bar driven by cauliflower mosaic virus 35S promoter were, used in this study. Embryogenic calli after co-cultivation with Agrobacterium were selected on the medium containing phosphinothricin. Southern blot analyses of primary transformants revealed the stable integration of bar, cry1Ab and cry1Ac coding sequences into the genomes of three parental lines with a predominant single copy integration and without any rearrangement of T-DNA. T1 progeny plants disclosed a monogenic pattern (3:1) of transgene segregation as confirmed by molecular analyses. Furthermore, the co-segregation of bar and cry genes in T1 progenies suggested that the transgenes are integrated at a single site in the rice genome. In different primary transformants with alien inbuilt resistance, the levels of cry proteins varied between 0.03 and 0.13% of total soluble proteins. These transgenic lines expressing insecticidal proteins afforded substantial resistance against stem borers. This is the first report of its kind dealing with the introduction of Bacillus thuringiensis (Bt) cry genes into the elite parental lines involved in the development of hybrid rice. PMID:15219400

Ramesh, S; Nagadhara, D; Pasalu, I C; Kumari, A Padma; Sarma, N P; Reddy, V D; Rao, K V

2004-07-15

7

Skin Fibroblasts from Patients with Type 1 Diabetes (T1D) Can Be Chemically Transdifferentiated into Insulin-Expressing Clusters: A Transgene-Free Approach  

PubMed Central

The conversion of differentiated cells into insulin-producing cells is a promising approach for the autologous replacement of pancreatic cells in patients with type 1 diabetes (T1D). At present, cellular reprogramming strategies encompass ethical problems, epigenetic failure or teratoma formation, which has prompted the development of new approaches. Here, we report a novel technique for the conversion of skin fibroblasts from T1D patients into insulin-expressing clusters using only drug-based induction. Our results demonstrate that skin fibroblasts from diabetic patients have pancreatic differentiation capacities and avoid the necessity of using transgenic strategies, stem cell sources or global demethylation steps. These findings open new possibilities for studying diabetes mechanisms, drug screenings and ultimately autologous transgenic-free regenerative medicine therapies in patients with T1D. PMID:24963634

Pereyra-Bonnet, Federico; Gimeno, Maria L.; Argumedo, Nelson R.; Ielpi, Marcelo; Cardozo, Johana A.; Gimenez, Carla A.; Hyon, Sung-Ho; Balzaretti, Marta; Loresi, Monica; Fainstein-Day, Patricia; Litwak, Leon E.; Argibay, Pablo F.

2014-01-01

8

Response of sensitive human ataxia and resistant T-1 cell lines to accelerated heavy ions  

SciTech Connect

The radiation dose responses of fibroblast from a patient with Ataxia telangiectasis (AT-2SF) and an established line of human T-1 cells were studied. Nearly monoenergetic accelerated neon and argon ions were used at the Berkeley Bevalac with various residual range values. The LET of the particles varied from 30 keV/..mu..m to over 1000 keV/..mu..m. All Ataxia survival curves were exponential functions of the dose. Their radiosensitivity reached peak values at 100 to 200 keV/..mu..m. Human T-1 cells have effective sublethal damage repair as has been evidenced by split dose experiments, and they are much more resistant to low LET than to high LET radiation. The repair-misrepair model has been used to interpret these results. We have obtained mathematical expressions that describe the cross sections and inactivation coefficients for both human cell lines as a function of the LET and the type of particle used. The results suggest either that high-LET particles induce a greater number of radiolesions per track or that heavy-ions at high LET induce lesions that kill cells more effectively and that are different from those produced at low LET. We assume that the lesions induced in T-1 and Ataxia cells are qualitatively similar and that each cell line attempts to repair these lesions. The result in most irradiated Ataxia cells, however, is either lethal misrepair or incomplete repair leading to cell death. 63 references, 10 figures, 1 table.

Tobias, C.A.; Blakely, E.A.; Chang, P.Y.; Lommel, L.; Roots, R.

1983-07-01

9

Generation of Doubled Haploid Transgenic Wheat Lines by Microspore Transformation  

PubMed Central

Microspores can be induced to develop homozygous doubled haploid plants in a single generation. In the present experiments androgenic microspores of wheat have been genetically transformed and developed into mature homozygous transgenic plants. Two different transformation techniques were investigated, one employing electroporation and the other co-cultivation with Agrobacterium tumefaciens. Different tissue culture and transfection conditions were tested on nine different wheat cultivars using four different constructs. A total of 19 fertile transformants in five genotypes from four market classes of common wheat were recovered by the two procedures. PCR followed by DNA sequencing of the products, Southern blot analyses and bio/histo-chemical and histological assays of the recombinant enzymes confirmed the presence of the transgenes in the T0 transformants and their stable inheritance in homozygous T1?2 doubled haploid progenies. Several decisive factors determining the transformation and regeneration efficiency with the two procedures were determined: (i) pretreatment of immature spikes with CuSO4 solution (500 mg/L) at 4°C for 10 days; (ii) electroporation of plasmid DNA in enlarged microspores by a single pulse of ?375 V; (iii) induction of microspores after transfection at 28°C in NPB-99 medium and regeneration at 26°C in MMS5 medium; (iv) co-cultivation with Agrobacterium AGL-1 cells for transfer of plasmid T-DNA into microspores at day 0 for <24 hours; and (v) elimination of AGL-1 cells after co-cultivation with timentin (200–400 mg/L). PMID:24260351

Liu, Weiguo; Konzak, Calvin F.; von Wettstein, Diter; Rustgi, Sachin

2013-01-01

10

Epigenetic variants of a transgenic petunia line show hypermethylation in transgene DNA: an indication for specific recognition of foreign DNA in transgenic plants  

Microsoft Academic Search

We analysed de novo DNA methylation occurring in plants obtained from the transgenic petunia line R101-17. This line contains one copy of the maize A1 gene that leads to the production of brick-red pelargonidin pigment in the flowers. Due to its integration into an unmethylated genomic region the A1 transgene is hypomethylated and transcriptionally active. Several epigenetic variants of line

P. Meyer; I. Heidmann

1994-01-01

11

Mice transgenic for CD4-specific human CD4, CCR5 and cyclin T1 expression: a new model for investigating HIV-1 transmission and treatment efficacy.  

PubMed

Mice cannot be used to evaluate HIV-1 therapeutics and vaccines because they are not infectible by HIV-1 due to structural differences between several human and mouse proteins required for HIV-1 entry and replication including CD4, CCR5 and cyclin T1. We overcame this limitation by constructing mice with CD4 enhancer/promoter-regulated human CD4, CCR5 and cyclin T1 genes integrated as tightly linked transgenes (hCD4/R5/cT1 mice) promoting their efficient co-transmission and enabling the murine CD4-expressing cells to support HIV-1 entry and Tat-mediated LTR transcription. All of the hCD4/R5/cT1 mice developed disseminated infection of tissues that included the spleen, small intestine, lymph nodes and lungs after intravenous injection with an HIV-1 infectious molecular clone (HIV-IMC) expressing Renilla reniformis luciferase (LucR). Furthermore, localized infection of cervical-vaginal mucosal leukocytes developed after intravaginal inoculation of hCD4/R5/cT1 mice with the LucR-expressing HIV-IMC. hCD4/R5/cT1 mice reproducibly developed in vivo infection after inoculation with LucR-expressing HIV-IMC which could be bioluminescently quantified and visualized with a high sensitivity and specificity which enabled them to be used to evaluate the efficacy of HIV-1 therapeutics. Treatment with highly active anti-retroviral therapy or one dose of VRC01, a broadly neutralizing anti-HIV-1 antibody, almost completed inhibited acute systemic HIV-1 infection of the hCD4/R5/cT1 mice. hCD4/R5/cT1 mice could also be used to evaluate the capacity of therapies delivered by gene therapy to inhibit in vivo HIV infection. VRC01 secreted in vivo by primary B cells transduced with a VRC01-encoding lentivirus transplanted into hCD4/R5/cT1 mice markedly inhibited infection after intravenous challenge with LucR-expressing HIV-IMC. The reproducible infection of CD4/R5/cT1 mice with LucR-expressing HIV-IMC after intravenous or mucosal inoculation combined with the availability of LucR-expressing HIV-IMC expressing transmitted/founder and clade A/E and C Envs will provide researchers with a highly accessible pre-clinical in vivo HIV-1-infection model to study HIV-1 acquisition, treatment, and prevention. PMID:23691059

Seay, Kieran; Qi, Xiaohua; Zheng, Jian Hua; Zhang, Cong; Chen, Ken; Dutta, Monica; Deneroff, Kathryn; Ochsenbauer, Christina; Kappes, John C; Littman, Dan R; Goldstein, Harris

2013-01-01

12

Mice Transgenic for CD4-Specific Human CD4, CCR5 and Cyclin T1 Expression: A New Model for Investigating HIV-1 Transmission and Treatment Efficacy  

PubMed Central

Mice cannot be used to evaluate HIV-1 therapeutics and vaccines because they are not infectible by HIV-1 due to structural differences between several human and mouse proteins required for HIV-1 entry and replication including CD4, CCR5 and cyclin T1. We overcame this limitation by constructing mice with CD4 enhancer/promoter-regulated human CD4, CCR5 and cyclin T1 genes integrated as tightly linked transgenes (hCD4/R5/cT1 mice) promoting their efficient co-transmission and enabling the murine CD4-expressing cells to support HIV-1 entry and Tat-mediated LTR transcription. All of the hCD4/R5/cT1 mice developed disseminated infection of tissues that included the spleen, small intestine, lymph nodes and lungs after intravenous injection with an HIV-1 infectious molecular clone (HIV-IMC) expressing Renilla reniformis luciferase (LucR). Furthermore, localized infection of cervical-vaginal mucosal leukocytes developed after intravaginal inoculation of hCD4/R5/cT1 mice with the LucR-expressing HIV-IMC. hCD4/R5/cT1 mice reproducibly developed in vivo infection after inoculation with LucR-expressing HIV-IMC which could be bioluminescently quantified and visualized with a high sensitivity and specificity which enabled them to be used to evaluate the efficacy of HIV-1 therapeutics. Treatment with highly active anti-retroviral therapy or one dose of VRC01, a broadly neutralizing anti-HIV-1 antibody, almost completed inhibited acute systemic HIV-1 infection of the hCD4/R5/cT1 mice. hCD4/R5/cT1 mice could also be used to evaluate the capacity of therapies delivered by gene therapy to inhibit in vivo HIV infection. VRC01 secreted in vivo by primary B cells transduced with a VRC01-encoding lentivirus transplanted into hCD4/R5/cT1 mice markedly inhibited infection after intravenous challenge with LucR-expressing HIV-IMC. The reproducible infection of CD4/R5/cT1 mice with LucR-expressing HIV-IMC after intravenous or mucosal inoculation combined with the availability of LucR-expressing HIV-IMC expressing transmitted/founder and clade A/E and C Envs will provide researchers with a highly accessible pre-clinical in vivo HIV-1-infection model to study HIV-1 acquisition, treatment, and prevention. PMID:23691059

Zheng, Jian Hua; Zhang, Cong; Chen, Ken; Dutta, Monica; Deneroff, Kathryn; Ochsenbauer, Christina; Kappes, John C.; Littman, Dan R.; Goldstein, Harris

2013-01-01

13

Efficient selection and evaluation of transgenic lines of Crambe abyssinica  

PubMed Central

Crambe abyssinica is a dedicated oilseed crop suitable for production of industrial feedstocks. Genetic modification of crambe has progressed substantially in the last few years, but the transformation efficiency needs to be further improved. Meanwhile, developing a reliable molecular system including Southern blot and qRT-PCR analyses is desired for effectively evaluating transgenic lines and gene expression levels of both endogenous and transgenes. In this study, we have developed an efficient transformation protocol with hygromycin as the selective agent for crambe transformation. In the regeneration test, addition of hygromycin at concentration of 5 mg L?1 resulted in 18% of shoot regeneration using crambe hypocotyls as explants, while no regeneration occurred when the hygromycin concentration reached 10 mg L?1. Based on this result, the hygromycin concentration up to 10 mg L?1 was used in the subsequent transformations. The results showed that the transformation efficiency under constant low selection pressure (H3-H3) was similar to that under higher selection pressure first, followed by transfer to lower selection pressure (H10-H3). The PCR, Southern blot and fatty acid composition analyses confirmed the integration of transgenes in the crambe genome. We have also optimized the Southern and qRT-PCR methods for future studies on crambe or related species. For Southern blot analysis on crambe, more than 50 ?g DNA is required for a clear band. The choice of enzymes for DNA digestion was not rigid for confirmation of the T-DNA integration, while for determining the copy number of transgenes, suitable enzymes should be chosen. Increasing the enzyme concentration could improve the digestion and 20 ?l enzyme was recomended for a complete digestion of up to 80 ?g crambe DNA. For qRT-PCR analysis, around 20 days after flowering was observed to be the suitable sampling time for expresseion analysis of genes invovled in the seed oil biosynthesis. PMID:23750164

Li, Xueyuan; Fan, Jing; Gruber, Jens; Guan, Rui; Frentzen, Margrit; Zhu, Li-Hua

2013-01-01

14

Case Study: Polycystic Livers in a Transgenic Mouse Line  

PubMed Central

Three mice (2 male, 1 female; age, 5 to 16 mo) from a mouse line transgenic for keratin 14 (K14)-driven LacZ expression and on an outbred Crl:CD1(ICR) background, were identified as having distended abdomens and livers that were diffusely enlarged by numerous cysts (diameter, 0.1 to 2.0 cm). Histopathology revealed hepatic cysts lined by biliary type epithelium and mild chronic inflammation, and confirmed the absence of parasites. Among 21 related mice, 5 additional affected mice were identified via laparotomy. Breeding of these 5 mice (after 5 mo of age) did not result in any offspring; the K14 mice with polycystic livers failed to reproduce. Affected male mice had degenerative testicular lesions, and their sperm was immotile. Nonpolycystic K14 control male mice bred well, had no testicular lesions, and had appropriate sperm motility. Genetic analysis did not identify an association of this phenotype with the transgene or insertion site. PMID:24674586

Lovaglio, Jamie; Artwohl, James E; Ward, Christopher J; Diekwisch, Thomas GH; Ito, Yoshihiro; Fortman, Jeffrey D

2014-01-01

15

Human cyclin T1 expression ameliorates a T-cell-specific transcriptional limitation for HIV in transgenic rats, but is not sufficient for a spreading infection of prototypic R5 HIV-1 strains ex vivo  

PubMed Central

Background Cells derived from native rodents have limits at distinct steps of HIV replication. Rat primary CD4 T-cells, but not macrophages, display a profound transcriptional deficit that is ameliorated by transient trans-complementation with the human Tat-interacting protein Cyclin T1 (hCycT1). Results Here, we generated transgenic rats that selectively express hCycT1 in CD4 T-cells and macrophages. hCycT1 expression in rat T-cells boosted early HIV gene expression to levels approaching those in infected primary human T-cells. hCycT1 expression was necessary, but not sufficient, to enhance HIV transcription in T-cells from individual transgenic animals, indicating that endogenous cellular factors are critical co-regulators of HIV gene expression in rats. T-cells from hCD4/hCCR5/hCycT1-transgenic rats did not support productive infection of prototypic wild-type R5 HIV-1 strains ex vivo, suggesting one or more significant limitation in the late phase of the replication cycle in this primary rodent cell type. Remarkably, we identify a replication-competent HIV-1 GFP reporter strain (R7/3 YU-2 Env) that displays characteristics of a spreading, primarily cell-to-cell-mediated infection in primary T-cells from hCD4/hCCR5-transgenic rats. Moreover, the replication of this recombinant HIV-1 strain was significantly enhanced by hCycT1 transgenesis. The viral determinants of this so far unique replicative ability are currently unknown. Conclusion Thus, hCycT1 expression is beneficial to de novo HIV infection in a transgenic rat model, but additional genetic manipulations of the host or virus are required to achieve full permissivity. PMID:19144136

Michel, Nico; Goffinet, Christine; Ganter, Kerstin; Allespach, Ina; KewalRamani, Vineet N; Saifuddin, Mohammed; Littman, Dan R; Greene, Warner C; Goldsmith, Mark A; Keppler, Oliver T

2009-01-01

16

In vivo immunomodulatory effects of Antrodia camphorata polysaccharides in a T1/T2 doubly transgenic mouse model for inhibiting infection of Schistosoma mansoni  

SciTech Connect

Antrodia camphorata (A. camphorata) is a fungus commonly used for treatment of viral hepatitis and cancer in Chinese folk medicine. Extract of A. camphorate is reported to possess anti-inflammatory, antihepatitis B virus and anticancer activities. In this study, we tested the in vivo effects of polysaccharides derived from A. camphorata (AC-PS) on immune function by detection of cytokine expression and evaluation of the immune phenotype in a T1/T2 doubly transgenic mouse model. The protective effect of AC-PS in mice was tested by infection with Schistosoma mansoni. The induction of large amounts of IFN-{gamma}, IL-2 and TNF-a mRNA were detected after 2 and 4 weeks of oral AC-PS administration in BALB/c and C57BL/6 mice. In transgenic mice, 3 to 6 weeks of oral AC-PS administration increased the proportion of CD4{sup +} T cells and B cells within the spleen. More specifically, there was an increase of Th1 CD4{sup +} T cells and Be1 cells among spleen cells as observed by detection the of Type1/Type2 marker molecules. By using a disease model of parasitic infection, we found that AC-PS treatment inhibited infection with S. mansoni in BALB/C and C57BL/6 mice. AC-PS appears to influence the immune system of mice into developing Th1 responses and have potential for preventing infection with S. mansoni.

Cheng, P.-C. [Institute of Tropical Medicine, National Yang-Ming University, Taipei, Taiwan (China); Hsu, C.-Y. [Institute of Molecular and Cellular Biology, National Tsing-Hua University, Hsinchu, Taiwan (China); Chen, C.-C. [Biotechnology Center, Grape King Inc., Chungli, Taiwan (China); Lee, K.-M. [Institute of Tropical Medicine, National Yang-Ming University, Taipei, Taiwan (China); Institute of Medical Biotechnology, Central Taiwan University of Science and Technology, Taichung, Taiwan (China)], E-mail: kmlee@ctust.edu.tw

2008-03-01

17

Characterization of a novel telomerase-immortalized human endometrial stromal cell line, St-T1b  

PubMed Central

Background Coordinated differentiation of the endometrial compartments in the second half of the menstrual cycle is a prerequisite for the establishment of pregnancy. Endometrial stromal cells (ESC) decidualize under the influence of ovarian progesterone to accommodate implantation of the blastocyst and support establishment of the placenta. Studies into the mechanisms of decidualization are often hampered by the lack of primary ESC. Here we describe a novel immortalized human ESC line. Methods Primary ESC were immortalized by the transduction of telomerase. The resultant cell line, termed St-T1b, was characterized for its morphological and biochemical properties by immunocytochemistry, RT-PCR and immunoblotting. Its progestational response was tested using progesterone and medroxyprogesterone acetate with and without 8-Br-cAMP, an established inducer of decidualization in vitro. Results St-T1b were positive for the fibroblast markers vimentin and CD90 and negative for the epithelial marker cytokeratin-7. They acquired a decidual phenotype indistinguishable from primary ESC in response to cAMP stimulation. The decidual response was characterized by transcriptional activation of marker genes, such as PRL, IGFBP1, and FOXO1, and enhanced protein levels of the tumor suppressor p53 and the metastasis suppressor KAI1 (CD82). Progestins alone had no effect on St-T1b cells, but medroxyprogesterone acetate greatly enhanced the cAMP-stimulated expression of IGFBP-1 after 3 and 7 days. Progesterone, albeit more weakly, also augmented the cAMP-induced IGFBP-1 production but only after 7 days of treatment. The cell line remained stable in continuous culture for more than 150 passages. Conclusion St-T1b express the appropriate phenotypic ESC markers and their decidual response closely mimics that of primary cultures. Decidualization is efficiently induced by cAMP analog and enhanced by medroxyprogesterone acetate, and, to a lesser extent, by natural progesterone. St-T1b cells therefore serve as a useful model for primary ESC. PMID:19619280

Samalecos, Annemarie; Reimann, Katja; Wittmann, Stefanie; Schulte, Heinrich M; Brosens, Jan J; Bamberger, Ana-Maria; Gellersen, Birgit

2009-01-01

18

Heat treatment results in a loss of transgene-encoded activities in several tobacco lines.  

PubMed Central

Heat treatment (37 degrees C) of transgenic tobacco (Nicotiana tabacum) plants led to a reversible reduction or complete loss of transgene-encoded activities in about 40% of 10 independent transformants carrying the luciferase-coding region fused to the 355 cauliflower mosaic virus or the soybean small subunit promoter and the nopaline synthase promoter driving the neomycin phosphotransferase gene, whereas the other lines had temperature-tolerant activities. Temperature sensitivity or tolerance of transgene-encoded activities was heritable. In some of the lines, temperature sensitivity of the transgene-encoded activities depended on the stage of development, occurring in either seedlings (40% luciferase and 50% neomycin phosphotransferase) or adult plants (both 40%). The phenomenon did not correlate with copy numbers or the homo- or hemizygous state of the transgenes. In lines harboring a temperature-sensitive luciferase activity, reduction of bioluminescence was observed after 2 to 3 h at 37 degrees C. Activity was regained after 2 h of subsequent cultivation at 25 degrees C. Irrespective of the reaction to the heat treatment, the level of luciferase RNA was slightly increased at 37 degrees C. Only in lines showing temperature sensitivity of transgene-encoded activities was the amount of luciferase and neomycin phosphotransferase strongly reduced. In sterile culture, heat treatment for 15 d did not cause visible damage or changes in plant morphology. In all plants tested a slight induction of the heat-shock response was observed at 37 degrees C. PMID:9390430

Neumann, K; Droge-Laser, W; Kohne, S; Broer, I

1997-01-01

19

Influence of Precursor Availability on Alkaloid Accumulation by Transgenic Cell Line of Catharanthus roseus  

Microsoft Academic Search

We have used a transgenic cell line of Catharanthus roseus (L.) G. Don to study the relative importance of the supply of biosynthetic precursors for the synthesis of terpenoid indole alkaloids. Line S10 carries a recombinant, constitutively overexpressed version of the endogenous strictosidine synthase (Str) gene. Various concentra- tions and combinations of the substrate tryptamine and of loganin, the immediate

Serap Whitmer; Camilo Canel; Didier Hallard; Cecilia Goncalves; Robert Verpoorte

1998-01-01

20

Beta-Cell Lines Derived from Transgenic Mice Expressing a Hybrid Insulin Gene-Oncogene  

Microsoft Academic Search

Three pancreatic beta-cell lines have been established from insulinomas derived from transgenic mice carrying a hybrid insulin-promoted simian virus 40 tumor antigen gene. The beta tumor cell (beta TC) lines maintain the features of differentiated beta cells for about 50 passages in culture. The cells produce both proinsulin I and II and efficiently process each into mature insulin, in a

Shimon Efrat; Susanne Linde; Hans Kofod; David Spector; Michael Delannoy; Seth Grant; Douglas Hanahan; Steinunn Baekkeskov

1988-01-01

21

Transgenesis and imaging in birds, and available transgenic reporter lines.  

PubMed

Avian embryos are important model organism to study higher vertebrate development. Easy accessibility to developing avian embryos enables a variety of experimental applications to understand specific functions of molecules, tissue-tissue interactions, and cell lineages. The whole-mount ex ovo culture technique for avian embryos permits time-lapse imaging analysis for a better understanding of cell behaviors underlying tissue morphogenesis in physiological conditions. To study mechanisms of blood vessel formation and remodeling in developing embryos by using a time-lapse imaging approach, a transgenic quail model, Tg(tie1:H2B-eYFP), was generated. From a cell behavior perspective, Tg(tie1:H2B-eYFP) quail embryos are a suitable model to shed light on how the structure and pattern of blood vessels are established in higher vertebrates. In this manuscript, we give an overview on the biological and technological background of the transgenic quail model and describe procedures for the ex ovo culture of quail embryos and time-lapse imaging analysis. PMID:23621574

Sato, Yuki; Lansford, Rusty

2013-05-01

22

Germline transmission of a novel rat embryonic stem cell line derived from transgenic rats.  

PubMed

Germline-competent rat embryonic stem (ES) cell lines are important resources for the creation of mutant rat models using ES-cell-based gene targeting technology. The ability to isolate germline-competent ES cell lines from any rat strain, including genetically modified strains, would allow for more sophisticated genetic manipulations without extensive breeding. Sprague Dawley (SD) males carrying an enhanced green fluorescent protein (EGFP) transgene were used as the founder animals for the derivation of ES cell lines. A number of ES cell lines were established and subjected to rigorous quality control testing that included assessment of pluripotency factor expression, karyotype analysis, and pathogen/sterility testing. Two male ES cell lines, SD-Tg.EC1/Rrrc and SD-Tg.EC8/Rrrc, were injected into blastocysts recovered from a cross of Dark Agouti (DA) males with SD females. Resulting chimeric animals were bred with wild-type SD mates to verify the germline transmissibility of the ES cell lines by identifying pups carrying the ES cell line-derived EGFP transgene. While both ES cell lines gave rise to chimeric animals, only SD-Tg.EC1 was germline competent. This confirms the feasibility of deriving germline-competent ES cell lines from transgenic rat strains and provides a novel ES cell line with a stable green fluorescent protein (GFP) reporter for future genetic manipulations to create new rat models. PMID:22455749

Men, Hongsheng; Bauer, Beth A; Bryda, Elizabeth C

2012-09-20

23

Transposon-mediated chromosomal integration of transgenes in the parasitic nematode Strongyloides ratti and establishment of stable transgenic lines.  

PubMed

Genetic transformation is a potential tool for analyzing gene function and thereby identifying new drug and vaccine targets in parasitic nematodes, which adversely affect more than one billion people. We have previously developed a robust system for transgenesis in Strongyloides spp. using gonadal microinjection for gene transfer. In this system, transgenes are expressed in promoter-regulated fashion in the F1 but are silenced in subsequent generations, presumably because of their location in repetitive episomal arrays. To counteract this silencing, we explored transposon-mediated chromosomal integration of transgenes in S. ratti. To this end, we constructed a donor vector encoding green fluorescent protein (GFP) under the control of the Ss-act-2 promoter with flanking inverted tandem repeats specific for the piggyBac transposon. In three experiments, free-living Strongyloides ratti females were transformed with this donor vector and a helper plasmid encoding the piggyBac transposase. A mean of 7.9% of F1 larvae were GFP-positive. We inoculated rats with GFP-positive F1 infective larvae, and 0.5% of 6014 F2 individuals resulting from this host passage were GFP-positive. We cultured GFP-positive F2 individuals to produce GFP-positive F3 L3i for additional rounds of host and culture passage. Mean GFP expression frequencies in subsequent generations were 15.6% in the F3, 99.0% in the F4, 82.4% in the F5 and 98.7% in the F6. The resulting transgenic lines now have virtually uniform GFP expression among all progeny after at least 10 generations of passage. Chromosomal integration of the reporter transgenes was confirmed by Southern blotting and splinkerette PCR, which revealed the transgene flanked by S. ratti genomic sequences corresponding to five discrete integration sites. BLAST searches of flanking sequences against the S. ratti genome revealed integrations in five contigs. This result provides the basis for two powerful functional genomic tools in S. ratti: heritable transgenesis and insertional mutagenesis. PMID:22912584

Shao, Hongguang; Li, Xinshe; Nolan, Thomas J; Massey, Holman C; Pearce, Edward J; Lok, James B

2012-01-01

24

Phenotypic and genotypic stability of multiple lines of transgenic pigs expressing recombinant human protein C  

Microsoft Academic Search

The genotypic and phenotypic stability of four lines of transgenic pigs expressing recombinant human protein C in milk was examined. Two lines were established with a construct consisting of a 2.6 kb mouse WAP promoter and a 9.4 kb human protein C genomic DNA. Two lines were established with another construct consisting of a 4.1 kb mouse WAP promoter and

Kevin E. Van Cott; Henryk Lubon; Christopher G. Russell; Stephen P. Butler; F. C. Gwazdauskas; James Knight; William N. Drohan; William H. Velander

1997-01-01

25

Derivation of a Germline Competent Transgenic Fischer 344 Embryonic Stem Cell Line  

PubMed Central

Embryonic stem (ES) cell-based gene manipulation is an effective method for the generation of mutant animal models in mice and rats. Availability of germline-competent ES cell lines from inbred rat strains would allow for creation of new genetically modified models in the desired genetic background. Fischer344 (F344) males carrying an enhanced green fluorescence protein (EGFP) transgene were used as the founder animals for the derivation of ES cell lines. After establishment of ES cell lines, rigorous quality control testing that included assessment of pluripotency factor expression, karyotype analysis, and pathogen/sterility testing was conducted in selected ES cell lines. One male ES cell line, F344-Tg.EC4011, was further evaluated for germline competence by injection into Dark Agouti (DA) X Sprague Dawley (SD) blastocysts. Resulting chimeric animals were bred with wild-type SD mates and germline transmissibility of the ES cell line was confirmed by identification of pups carrying the ES cell line-derived EGFP transgene. This is the first report of a germline competent F344 ES cell line. The availability of a new germline competent ES cell line with a stable fluorescence reporter from an inbred transgenic rat strain provides an important new resource for genetic manipulations to create new rat models. PMID:23437152

Men, Hongsheng; Bryda, Elizabeth C.

2013-01-01

26

Double conditional human embryonic kidney cell line based on FLP and ?C31 mediated transgene integration  

PubMed Central

Background FLP recombinase mediated integration into a pre-integrated FRT site is routinely used to generate highly reproducible stable transgenic cell lines. In this study, we broaden the system of site specific integration by introducing ?C31 integrase mediated integration into attP sites. Results We generated a HEK293 host cell line with a single copy FRT as well as an attP site allowing site specific integration of two distinct transgenes. To achieve conditional control, we used the tetracycline and Shld1 inducible systems. By introducing fluorescent reporters we show that integration and induction of two transgenes are completely independent. We applied this new technique to investigate the effect of HNF4? on proliferation of HEK293 cells by introducing HNF4? into each integration site. We obtained in two independent cell lines highly reproducible results that prove the usefulness of this novel HEK-attP/FRT cell line. Conclusions In this study we have established and applied a HEK-attP/FRT cell line that allows site specific integration of two conditional transgenes using the FLP recombinase as well as the ?C31 integrase. PMID:22008483

2011-01-01

27

Efficient germ-line transmission obtained with transgene-free induced pluripotent stem cells  

PubMed Central

Induced pluripotent stem (iPS) cells hold great promise for regenerative medicine. To overcome potential problems associated with transgene insertions, efforts have been directed over the past several years to generate transgene-free iPS cells by using non-viral-vector approaches. To date, however, cells generated through such procedures have had problems producing reproductively competent animals, suggesting that their quality needed further improvement. Here we report the use of optimized assemblies of reprogramming factors and selection markers incorporated into single plasmids as nonintegrating episomes to generate germ-line–competent iPS cells. In particular, the pMaster12 episome can produce transgene-free iPS cells that, when grown in 2i medium, recapitulate good mouse ES cells, in terms of their competency for generating germ-line chimeras. PMID:25002522

Wu, Sen; Wu, Yuanyuan; Zhang, Xi; Capecchi, Mario R.

2014-01-01

28

A muscle-specific transgenic reporter line of the sea anemone, Nematostella vectensis  

E-print Network

A muscle-specific transgenic reporter line of the sea anemone, Nematostella vectensis Eduard, and approved November 13, 2009 (received for review August 13, 2009) The sea anemone, Nematostella vectensis networks and developmental processes in the nonbilaterian sea anemone, Nematostella vectensis. meganuclease

Gibson, Matt

29

Production of fat-1 transgenic rats using a post-natal female germline stem cell line.  

PubMed

Germline stem cell lines possess the abilities of self-renewal and differentiation, and have been established from both mouse and human ovaries. Here, we established a new female germline stem cell (FGSC) line from post-natal rats by immunomagnetic sorting for Fragilis, which showed a normal karyotype, high telomerase activity, and a consistent gene expression pattern of primordial germ cells after 1 year of culture. Using an in vitro differentiation system, the FGSC line could differentiate into oocytes. After liposome-based transfection with green fluorescent protein (GFP) or fat-1 vectors, the FGSCs were transplanted into the ovaries of infertile rats. The transplanted FGSCs underwent oogenesis, and the rats produced offspring carrying the GFP or fat-1 transgene after mating with wild-type male rats. The efficiency of gene transfer was 27.86-28.00%, and 2 months was needed to produce transgenic rats. These findings have implications in biomedical research and potential applications in biotechnology. PMID:24258451

Zhou, Li; Wang, Lei; Kang, Jing X; Xie, Wenhai; Li, Xiaoyong; Wu, Changqing; Xu, Bo; Wu, Ji

2014-03-01

30

Analysis of cell-specificity and variegation of transgene expression driven by salmon prolactin promoter in stable lines of transgenic rainbow trout.  

PubMed

In order to identify the specificity and functionality of salmon prolactin (sPRL) promoter, transgenic rainbow trout carrying a construct comprising the 2.4 kb fragment of the 5' flanking region of Atlantic Chinook sPRL gene fused either to the reporter genes cat (sPRL-cat) or lacZ (sPRL-lacZ) were produced. sPRL-cat in transgenic F0 fish expressed strongly CAT only in the pituitary gland. Transgenic in F1-F4 lines harbouring sPRL-lacZ expressed beta-galactosidase (beta-gal) only in the follicular PRL-producing cells of the adenohypophysis. We observed heterocellular, mosaic distribution of beta-gal within PRL cell population and enormous variation of lacZ expression level between the littermates in the same transgenic line. Regardless of the transgene copy number, age or sex of transgenic fish, beta-gal expression was lactotroph-specific but variegated in all the nine F2 hemizygous lines analysed. One line harbouring a multicopy integration was followed up to F4 generation: the transgene was transmitted without modifications. Analysis of genomic DNA from pituitaries showed that lacZ sequences were highly methylated. LacZ expression was low and its transcripts, analysed by in situ hybridisation, showed a mosaic distribution within the pituitary gland. These data suggest that variegated expression of lacZ can occur at the transcription level owing to the silencing effect of lacZ gene. After proving the tissue-specific expression of reporter genes driven by the sPRL promoter, we tried to obtain the genetic ablation of PRL-producing cells,by transferring the same construct comprising diphtheria toxin DT-A gene (tox). However, the high mortality rate of sPRL-tox transformed embryos has embedded this study and no transgenic fish expressing tox were produced. The appropriateness of using transgenic strategies to analyse gene function in Salmonids is discussed, especially the implications of the multicopy integration patterns and of the variegated transgene expression. PMID:12739889

Uzbekova, Svetlana; Amoros, Claire; Cauty, Chantale; Mambrini, Muriel; Perrot, Elizabeth; Hew, Choy L; Chourrout, Daniel; Prunet, Patrick

2003-04-01

31

RAPD and SSR Polymorphisms in Mutant Lines of Transgenic Wheat Mediated by Low Energy Ion Beam  

NASA Astrophysics Data System (ADS)

Two types of markers-random amplified polymorphic DNA (RAPD) and simple sequence repeat DNA (SSR)-have been used to characterize the genetic diversity among nine mutant lines of transgenic wheat intermediated by low energy ion beam and their four receptor cultivars. The objectives of this study were to analyze RAPD-based and SSR-based genetic variance among transgenic wheat lines and with their receptors, and to find specific genetic markers of special traits of transgenic wheat lines. 170 RAPD primers were amplified to 733 fragments in all the experimental materials. There were 121 polymorphic fragments out of the 733 fragments with a ratio of polymorphic fragments of 16.5%. 29 SSR primer pairs were amplified to 83 fragments in all the experiment materials. There were 57 polymorphic fragments out of the 83 fragments with a ratio of polymorphic fragments of 68.7%. The dendrograms were prepared based on a genetic distance matrix using the UPGMA (Unweighted Pair-group Method with Arithmetic averaging) algorithm, which corresponded well to the results of the wheat pedigree analysis and separated the 13 genotypes into four groups. Association analysis between RAPD and SSR markers with the special traits of transgenic wheat mutant lines discovered that three RAPD markers, s1, opt-16, and f14, were significantly associated with the muticate trait, while three SSR markers, Rht8 (Xgwm261), Rht-B1b, and Rht-D1b, highly associated with the dwarf trait. These markers will be useful for marker-assistant breeding and can be used as candidate markers for further gene mapping and cloning.

Wang, Tiegu; Huang, Qunce; Feng, Weisen

2007-10-01

32

Evaluation of the Agronomic Performance of Atrazine-Tolerant Transgenic japonica Rice Parental Lines for Utilization in Hybrid Seed Production  

PubMed Central

Currently, the purity of hybrid seed is a crucial limiting factor when developing hybrid japonica rice (Oryza sativa L.). To chemically control hybrid seed purity, we transferred an improved atrazine chlorohydrolase gene (atzA) from Pseudomonas ADP into hybrid japonica parental lines (two maintainers, one restorer), and Nipponbare, by using Agrobacterium-mediated transformation. We subsequently selected several transgenic lines from each genotype by using PCR, RT-PCR, and germination analysis. In the presence of the investigated atrazine concentrations, particularly 150 µM atrazine, almost all of the transgenic lines produced significantly larger seedlings, with similar or higher germination percentages, than did the respective controls. Although the seedlings of transgenic lines were taller and gained more root biomass compared to the respective control plants, their growth was nevertheless inhibited by atrazine treatment compared to that without treatment. When grown in soil containing 2 mg/kg or 5 mg/kg atrazine, the transgenic lines were taller, and had higher total chlorophyll contents than did the respective controls; moreover, three of the strongest transgenic lines completely recovered after 45 days of growth. After treatment with 2 mg/kg or 5 mg/kg of atrazine, the atrazine residue remaining in the soil was 2.9–7.0% or 0.8–8.7% respectively, for transgenic lines, and 44.0–59.2% or 28.1–30.8%, respectively, for control plants. Spraying plants at the vegetative growth stage with 0.15% atrazine effectively killed control plants, but not transgenic lines. Our results indicate that transgenic atzA rice plants show tolerance to atrazine, and may be used as parental lines in future hybrid seed production. PMID:25275554

Li, Yanlan; Li, Yanan; Wang, Shengjun; Su, Jinping; Liu, Xuejun; Chen, Defu; Chen, Xiwen

2014-01-01

33

A Phox2b::FLPo transgenic mouse line suitable for intersectional genetics  

PubMed Central

Phox2b is a transcription factor expressed in the central and peripheral neurons that control cardiovascular, respiratory and digestive functions and essential for their development. Several populations known or suspected to regulate visceral functions express Phox2b in the developing hindbrain. Extensive cell migration and lack of suitable markers have greatly hampered studying their development. Reasoning that intersectional fate mapping may help to overcome these impediments, we have generated a BAC transgenic mouse line, P2b::FLPo, which expresses codon-optimized FLP recombinase in Phox2b expressing cells. By partnering the P2b::FLPo with the FLP-responsive RC::Fela allele, we show that FLP recombination switches on lineage tracers in the cells that express or have expressed Phox2b, permanently marking them for study across development. Taking advantage of the dualrecombinase feature of RC::Fela, we further show that the P2b::FLPo transgene can be partnered with Lbx1Cre as Cre driver to generate triple transgenics in which neurons having a history of both Phox2b and Lbx1 expression are specifically labelled. Hence, the P2b::FLPo line when partnered with a suitable Cre driver provides a tool for tracking and accessing genetically subsets of Phox2b-expressing neuronal populations, which has not been possible by Cremediated recombination alone. PMID:23592597

Hirsch, Marie-Rose; d'Autreaux, Fabien; Dymecki, Susan M.; Brunet, Jean-Francois; Goridis, Christo

2014-01-01

34

RNAi-mediated Ultra-low gossypol cottonseed trait: performance of transgenic lines under field conditions.  

PubMed

Cottonseed remains a low-value by-product of lint production mainly due to the presence of toxic gossypol that makes it unfit for monogastrics. Ultra-low gossypol cottonseed (ULGCS) lines were developed using RNAi knockdown of ?-cadinene synthase gene(s) in Gossypium hirsutum. The purpose of the current study was to assess the stability and specificity of the ULGCS trait and evaluate the agronomic performance of the transgenic lines. Trials conducted over a period of 3 years show that the ULGCS trait was stable under field conditions and the foliage/floral organs of transgenic lines contained wild-type levels of gossypol and related terpenoids. Although it was a relatively small-scale study, we did not observe any negative effects on either the yield or quality of the fibre and seed in the transgenic lines compared with the nontransgenic parental plants. Compositional analysis was performed on the seeds obtained from plants grown in the field during 2009. As expected, the major difference between the ULGCS and wild-type cottonseeds was in terms of their gossypol levels. With the exception of oil content, the composition of ULGCS was similar to that of nontransgenic cottonseeds. Interestingly, the ULGCS had significantly higher (4%-8%) oil content compared with the seeds from the nontransgenic parent. Field trial results confirmed the stability and specificity of the ULGCS trait suggesting that this RNAi-based product has the potential to be commercially viable. Thus, it may be possible to enhance and expand the nutritional utility of the annual cottonseed output to fulfil the ever-increasing needs of humanity. PMID:23078138

Palle, Sreenath R; Campbell, Leanne M; Pandeya, Devendra; Puckhaber, Lorraine; Tollack, Lauren K; Marcel, Sylvain; Sundaram, Sabarinath; Stipanovic, Robert D; Wedegaertner, Thomas C; Hinze, Lori; Rathore, Keerti S

2013-04-01

35

Developmental toxicology of cadmium in living embryos of a stable transgenic zebrafish line.  

PubMed Central

The toxic effects of cadmium and other heavy metals have been well established, and many of these and other environmental pollutants are known to be embryotoxic or teratogenic. However, it has proven difficult to identify individual cells that respond to toxicants among the wide range of cell populations in an intact animal, particularly during early development when cells are continually changing their molecular and physiologic characteristics as they differentiate. Here we report the establishment of an in vivo system that uses hsp70 gene activation as a measure of cadmium toxicity in living early larvae of transgenic zebrafish carrying a stably integrated hsp70-enhanced green fluorescent protein (eGFP) reporter gene. We demonstrate that eGFP expression in this strain of fish acts as an accurate and reproducible indicator of cell-specific induction of hsp70 gene expression. Furthermore, the transgene responds in a dose-dependent manner at concentrations similar to those observed for morphologic indicators of early-life-stage toxicity and is sensitive enough to detect cadmium at doses below the median combined adverse effect concentration and the median lethal concentration. The stable nature of this transgenic line should allow for extremely rapid and reproducible toxicologic profiling of embryos and larvae throughout development. PMID:12361930

Blechinger, Scott R; Warren, James T; Kuwada, John Y; Krone, Patrick H

2002-01-01

36

Transgene-mediated cosuppression and RNA interference enhance germ-line apoptosis in Caenorhabditis elegans.  

PubMed

Introduction of multiple copies of a germ-line-expressed gene elicits silencing of the corresponding endogenous gene during Caenorhabditis elegans oogenesis; this process is referred to as germ-line cosuppression. Transformed plasmids assemble into extrachromosomal arrays resembling extra minichromosomes with repetitive structures. Loss of the transgene extrachromosomal array leads to reversion of the silencing phenomenon. Cosuppression and RNAi depend upon some of the same genes. In the C. elegans germ line, about half the cells undergo a physiological programmed cell death that shares most genetic requirements with somatic apoptosis. In addition, apoptosis is stimulated by DNA damage and synaptic failure mediated through different apoptotic checkpoints. We found that both germ-line cosuppression and RNAi of germ-line-expressed genes enhance apoptosis during C. elegans oogenesis. In contrast, apoptosis is not enhanced by extrachromosomal arrays carrying genes not driven by germ-line-specific promoters that thus do not elicit transgene-mediated cosuppression/silencing. Similarly, introduction of doubled-stranded RNA that shares no homology with endogenous genes has no effect on apoptosis. "Silencing-induced apoptosis" is dependent upon sir-2.1 and cep-1 (the worm p53 ortholog), and is accompanied by a rise in RAD-51 foci, a marker for ongoing DNA repair, indicating induction of DNA double-strand breaks. This finding suggests that the DNA damage-response pathway is involved. RNAi and cosuppression have been postulated as defense mechanisms against genomic intruders. We speculate that the mechanism here described may trigger the elimination of germ cells that have undergone viral infection or transposon activation. PMID:22331911

Adamo, Adele; Woglar, Alexander; Silva, Nicola; Penkner, Alexandra; Jantsch, Verena; La Volpe, Adriana

2012-02-28

37

Mobility properties of the Hermes transposable element in transgenic lines of Aedes aegypti  

PubMed Central

The Hermes transposable element has been used to genetically transform a wide range of insect species, including the mosquito, Aedes aegypti, a vector of several important human pathogens. Hermes integrations into the mosquito germline are characterized by the non-canonical integration of the transposon and flanking plasmid and, once integrated, Hermes is stable in the presence of its transposase. In an effort to improve the post-integration mobility of Hermes in the germline of Ae. aegypti, a transgenic helper Mos1 construct expressing Hermes transposase under the control of a testis-specific promoter was crossed to a separate transgenic strain containing a target Hermes transposon. In less than 1% of the approximately 1,500 progeny from jumpstarter lines analyzed, evidence of putative Hermes germline remobilizations were detected. These recovered transposition events occur through an aberrant mechanism and provide insight into the non-canonical cut-and-paste transposition of Hermes in the germ line of Ae. aegypti. PMID:20596755

Smith, Ryan C.

2010-01-01

38

Longitudinal Karyotype and Genetic Signature Analysis of Cultured Human Colon Adenocarcinoma Cell Lines LS180 and LS174T1  

Microsoft Academic Search

Giemsa-banded chromosomes were analyzed at intervals during either 34 or 70 serial subcultivations of two cell lines, LS180 and LS174T, established from one primary human colon adenocarcinoma, and at passage 14 of autochthonous normal bowel cells, NB(LS1 74T). The cell lines were estab lished and subcultured by either scraping or trypsin treatment of primary cultures; the scraped cell line was

Lynne P. Rutzky; Celia I. Kaye; Michael J. Siciliano; Margaret Chao; Barry D. Kahan

1980-01-01

39

An Improved BAC Transgenic Fluorescent Reporter Line for Sensitive and Specific Identification of Striatonigral Medium Spiny Neurons  

PubMed Central

The development of BAC transgenic mice expressing promoter-specific fluorescent reporter proteins has been a great asset for neuroscience by enabling detection of neuronal subsets in live tissue. For the study of basal ganglia physiology, reporters driven by type 1 and 2 dopamine receptors have been particularly useful for distinguishing the two classes of striatal projection neurons – striatonigral and striatopallidal. However, emerging evidence suggests that some of the transgenic reporter lines may have suboptimal features. The ideal transgenic reporter line should (1) express a reporter with high sensitivity and specificity for detecting the cellular subset of interest and that does not otherwise alter the biology of the cells in which it is expressed, and (2) involve a genetic manipulation that does not cause any additional genetic effects other than expression of the reporter. Here we introduce a new BAC transgenic reporter line, Drd1a-tdTomato line 6, with features that approximate these ideals, offering substantial benefits over existing lines. In this study, we investigate the integrity of dopamine-sensitive behaviors and test the sensitivity and specificity of tdTomato fluorescence for identifying striatonigral projection neurons in mice. Behaviorally, hemizygous Drd1a-tdTomato line 6 mice are similar to littermate controls; while hemizygous Drd2-EGFP mice are not. In characterizing the sensitivity and specificity of line 6 mice, we find that both are high. The results of this characterization indicate that line 6 Drd1a-tdTomato+/? mice offer a useful alternative approach to identify both striatonigral and striatopallidal neurons in a single transgenic line with a high degree of accuracy. PMID:21713123

Ade, Kristen K.; Wan, Yehong; Chen, Meng; Gloss, Bernd; Calakos, Nicole

2011-01-01

40

Beneficial 'unintended effects' of a cereal cystatin in transgenic lines of potato, Solanum tuberosum  

PubMed Central

Background Studies reported unintended pleiotropic effects for a number of pesticidal proteins ectopically expressed in transgenic crops, but the nature and significance of such effects in planta remain poorly understood. Here we assessed the effects of corn cystatin II (CCII), a potent inhibitor of C1A cysteine (Cys) proteases considered for insect and pathogen control, on the leaf proteome and pathogen resistance status of potato lines constitutively expressing this protein. Results The leaf proteome of lines accumulating CCII at different levels was resolved by 2-dimensional gel electrophoresis and compared with the leaf proteome of a control (parental) line. Out of ca. 700 proteins monitored on 2-D gels, 23 were significantly up- or downregulated in CCII-expressing leaves, including 14 proteins detected de novo or up-regulated by more than five-fold compared to the control. Most up-regulated proteins were abiotic or biotic stress-responsive proteins, including different secretory peroxidases, wound inducible protease inhibitors and pathogenesis-related proteins. Accordingly, infection of leaf tissues by the fungal necrotroph Botryris cinerea was prevented in CCII-expressing plants, despite a null impact of CCII on growth of this pathogen and the absence of extracellular Cys protease targets for the inhibitor. Conclusions These data point to the onset of pleiotropic effects altering the leaf proteome in transgenic plants expressing recombinant protease inhibitors. They also show the potential of these proteins as ectopic modulators of stress responses in planta, useful to engineer biotic or abiotic stress tolerance in crop plants of economic significance. PMID:23116303

2012-01-01

41

Phototropism and gravitropism in transgenic lines of Arabidopsis altered in the phytochrome pathway.  

PubMed

Phytochromes are a family of photoreceptor molecules, absorbing primarily in red and far-red, that are important in many aspects of plant development. These studies investigated the role of phytochromes in phototropism and gravitropism of seedlings of Arabidopsis thaliana. We used two transgenic lines, one which lacked phytochromes specifically in the roots (M0062/UASBVR) and the other lacked phytochromes in the shoots (CAB3::pBVR). These transgenic plants are deficient in the phytochrome chromophore in specific tissues due the expression of biliverdin IXa reductase (BVR), which binds to precursors of the chromophore. Experiments were performed in both light and dark conditions to determine whether roots directly perceive light signals or if the signal is perceived in the shoot and then transmitted to the root during tropistic curvature. Kinetics of tropisms and growth were assayed by standard methods or with a computer-based feedback system. We found that the perception of red light occurs directly in the root during phototropism in this organ and that signaling also may occur from root to shoot in gravitropism. PMID:22380624

Hopkins, Jane A; Kiss, John Z

2012-07-01

42

Establishment and characterization of fetal fibroblast cell lines for generating human lysozyme transgenic goats by somatic cell nuclear transfer.  

PubMed

This study was performed to qualify goat fetal fibroblast (GFF) cell lines for genetic modification and somatic cell nuclear transfer (SCNT) to produce human lysozyme (hLYZ) transgenic goats. Nine GFF cell lines were established from different fetuses, and the proliferative lifespan and chromosomal stability were analyzed. The results suggested that cell lines with a longer lifespan had stable chromosomes compared with those of cells lines with a shorter lifespan. According to the proliferative lifespan, we divided GFF cell lines into two groups: cell lines with a long lifespan (GFF1/2/7/8/9; group L) and cell lines with a short lifespan (GFF3/4/5/6; group S). Next, a hLYZ expression vector was introduced into these cell lines by electroporation. The efficiencies of colony formation, expansion in culture, and the quality of transgenic clonal cell lines were significant higher in group L than those in group S. The mean fusion rate and blastocyst rate in group L were higher than those in group S (80.3 ± 1.7 vs. 65.1 ± 4.2 % and 19.5 ± 0.6 vs. 15.1 ± 1.1 %, respectively, P < 0.05). After transferring cloned embryos into the oviducts of recipient goats, three live kids were born. PCR and Southern blot analyses confirmed integration of the transgene in cloned goats. In conclusion, the lifespan of GFF cell lines has a major effect on the efficiency to produce transgenic cloned goats. Therefore, the proliferative lifespan of primary cells may be used as a criterion to characterize the quality of cell lines for genetic modification and SCNT. PMID:23335060

Liu, Jun; Luo, Yan; Zheng, Liming; Liu, Qingqing; Yang, Zhongcai; Wang, Yongsheng; Su, Jianmin; Quan, Fusheng; Zhang, Yong

2013-10-01

43

STI571 (Glivec) suppresses the expression of vascular endothelial growth factor in the gastrointestinal stromal tumor cell line, GIST-T1  

PubMed Central

AIM: To estimate whether STI571 inhibits the expression of vascular endothelial growth factor (VEGF) in the gastrointestinal stromal tumor (GIST) cells. METHODS: We used GIST cell line, GIST-T1. It has a heterogenic 57-bp deletion in exon 11 to produce a mutated c-KIT, which results in constitutive activation of c-KIT. Cells were treated with/without STI571 or stem cell factor (SCF). Transcription and expression of VEGF were determined by RT-PCR and flow cytometry or Western blotting, respectively. Activated c-KIT was estimated by immunoprecipitation analysis. Cell viability was determined by MTT assay. RESULTS: Activation of c-KIT was inhibited by STI571 treatment. VEGF was suppressed at both the transcriptional and translational levels in a temporal and dose-dependent manner by STI571. SCF upregulated the expression of VEGF and it was inhibited by STI571. STI571 also reduced the cell viability of the GIST-T1 cells, as determined by MTT assay. CONCLUSION: Activation of c-KIT in the GIST-T1 regulated the expression of VEGF and it was inhibited by STI571. STI571 has antitumor effects on the GIST cells with respect to not only the inhibition of cell growth. but also the suppression of VEGF expression. PMID:16521182

Jin, Toufeng; Nakatani, Hajime; Taguchi, Takahiro; Nakano, Takumi; Okabayashi, Takehiro; Sugimoto, Takeki; Kobayashi, Michiya; Araki, Keijiro

2006-01-01

44

Performance and long-term stability of the barley hordothionin gene in multiple transgenic apple lines.  

PubMed

Introduction of sustainable scab resistance in elite apple cultivars is of high importance for apple cultivation when aiming at reducing the use of chemical crop protectants. Genetic modification (GM) allows the rapid introduction of resistance genes directly into high quality apple cultivars. Resistance genes can be derived from apple itself but genetic modification also opens up the possibility to use other, non-host resistance genes. A prerequisite for application is the long-term performance and stability of the gene annex trait in the field. For this study, we produced and selected a series of transgenic apple lines of two cultivars, i.e. 'Elstar' and 'Gala' in which the barley hordothionin gene (hth) was introduced. After multiplication, the GM hth-lines, non-GM susceptible and resistant controls and GM non-hth controls were planted in a random block design in a field trial in 40 replicates. Scab resistance was monitored after artificial inoculation (first year) and after natural infection (subsequent years). After the trial period, the level of expression of the hth gene was checked by quantitative RT-PCR. Four of the six GM hth apple lines proved to be significantly less susceptible to apple scab and this trait was found to be stable for the entire 4-year period. Hth expression at the mRNA level was also stable. PMID:21243525

Krens, Frans A; Schaart, Jan G; Groenwold, Remmelt; Walraven, A Evert J; Hesselink, Thamara; Thissen, Jac T N M

2011-10-01

45

CRISPR/Cas9-mediated conversion of eGFP- into Gal4-transgenic lines in zebrafish.  

PubMed

Here we present a protocol for the conversion of eGFP-transgenic zebrafish lines into lines expressing Gal4 from the same locus. This conversion allows the in-depth analysis of the former eGFP-expressing cell population; with the Gal4-upstream activating sequence (UAS) system, diverse UAS transgenes can be transactivated. Site-specific targeting of the gene encoding eGFP is achieved using the clustered regularly interspaced short palindromic repeats/CRISPR-associated 9 (CRISPR/Cas9) system. A single-guide RNA (sgRNA) that targets eGFP is injected into embryos together with a donor vector containing an optimized version of Gal4 (KalTA4) to trigger integration of the donor into the targeted eGFP genomic location. To enable screening for successful integration events, injection is performed in a UAS:RFP transgenic background; fish showing mosaic eGFP-to-RFP conversion are raised to adulthood. The progeny of these adult fish are then screened for stable germline transmission, and converted progeny are used to generate stable lines. We have been able to generate two stably converted transgenic lines within 4 months. PMID:25393779

Auer, Thomas O; Duroure, Karine; Concordet, Jean-Paul; Del Bene, Filippo

2014-12-01

46

Zebrafish Transgenic Line huORFZ Is an Effective Living Bioindicator for Detecting Environmental Toxicants  

PubMed Central

Reliable animal models are invaluable for monitoring the extent of pollution in the aquatic environment. In this study, we demonstrated the potential of huORFZ, a novel transgenic zebrafish line that harbors a human upstream open reading frame of the chop gene fused with GFP reporter, as an animal model for monitoring environmental pollutants and stress-related cellular processes. When huORFZ embryos were kept under normal condition, no leaked GFP signal could be detected. When treated with hazardous chemicals, including heavy metals and endocrine-disrupting chemicals near their sublethal concentrations (LC50), huORFZ embryos exhibited different tissue-specific GFP expression patterns. For further analysis, copper (Cu2+), cadmium (Cd2+) and Chlorpyrifos were applied. Cu2+ triggered GFP responses in skin and muscle, whereas Cd2+ treatment triggered GFP responses in skin, olfactory epithelium and pronephric ducts. Moreover, fluorescence intensity, as exhibited by huORFZ embryos, was dose-dependent. After surviving treated embryos were returned to normal condition, survival rates, as well as TUNEL signals, returned to pretreatment levels with no significant morphological defects observed. Such results indicated the reversibility of treatment conditions used in this study, as long as embryos survived such conditions. Notably, GFP signals decreased along with recovery, suggesting that GFP signaling of huORFZ embryos likely reflected the overall physiological condition of the individual. To examine the performance of the huORFZ line under real-world conditions, we placed huORFZ embryos in different river water samples. We found that the huORFZ embryos correctly detected the presence of various kinds of pollutants. Based on these findings, we concluded that such uORFchop-based system can be integrated into a first-line water alarm system monitoring the discharge of hazardous pollutants. PMID:24594581

Chu, Chien; Li, Hong-Ping; Tsai, Huai-Jen

2014-01-01

47

Seasonal expression of Bt proteins in transgenic rice lines and the resistance against Asiatic rice borer Chilo suppressalis (Walker).  

PubMed

Laboratory bioassays and field surveys were carried out to compare the resistance of three transgenic rice (Oryza sativa L.) lines including Bt-DL expressing a single gene cry1Ab, Bt-KF6 expressing stacked genes cry1Ac and CpTI genes and Bt-SY63 expressing a fusion gene cry1Ab/cry1Ac, respectively, to an important rice pest Chilo suppressalis (Walker). In addition, enzyme-linked immunosorbent assays (ELISA) were conducted to monitor the Bt protein expressions in rice leaves and stems at different rice growth stages. Results showed that all the transgenic rice lines exhibited significantly high resistance to the pest compared with their corresponding nontransformed isolines. Among the transgenic rice lines, Bt-SY63 and Bt-KF6 had higher resistance to C. suppressalis at early growth stage, but lower resistance at late stages, while the pest resistance of Bt-DL was relatively stable throughout the growing season. The results were consistent with ELISA results showing that Bt protein levels in Bt-SY63 or Bt-KF6 leaves decreased in late growth stages, but were relatively stable in Bt-DL at all growth stages. This demonstrates that the resistance to a pest by Bt plants is positively correlated with Cry protein expression levels in plant tissues. Compared with Bt-SY63 and Bt-KF6, the Bt protein expression levels were significantly lower in Bt-DL, while its resistance to C. suppressalis was the highest. This may suggest that C. suppressalis is more susceptible to Cry1Ab than to Cry1Ac. The data from the current study are valuable for decision-making for commercial use of Bt rice lines and development of appropriate pest control and resistance management strategies for the transgenic rice lines. PMID:22251743

Zhang, Yongjun; Li, Yunhe; Zhang, Ying; Chen, Yang; Wu, Kongming; Peng, Yufa; Guo, Yuyuan

2011-10-01

48

Adeno-associated virus (AAV)-mediated transduction of male germ line stem cells results in transgene transmission after germ cell transplantation  

Microsoft Academic Search

We explored whether exposure of mam- malian germ line stem cells to adeno-associated virus (AAV), a gene therapy vector, would lead to stable transduction and transgene transmission. Mouse germ cells harvested from experimentally induced crypt- orchid donor testes were exposed in vitro to AAV vectors carrying a GFP transgene and transplanted to germ cell-depleted syngeneic recipient testes, resulting in colonization

Ali Honaramooz; Susan Megee; Wenxian Zeng; Margret M. Destrempes; Susan A. Overton; Jinping Luo; Hannah Galantino-Homer; Mark Modelski; Fangping Chen; Stephen Blash; David T. Melican; William G. Gavin; Sandra Ayres; Fang Yang; P. Jeremy Wang; Yann Echelard; Ina Dobrinski

2007-01-01

49

Enhanced expression of c-myc and decreased expression of c-fos protooncogenes in chemically and radiation-transformed C/sub 3/H/10T1/2 Cl 8 mouse embryo cell lines  

SciTech Connect

c-abl, c-fos, c-Ha-ras, c-myc, and c-mos were expressed whereas c-sis, c-fms, c-rel, c-src, and c-myb expression was not detectable in C/sub 3/H/10T1/2 Cl 8 (10T1/2) cells and in eight chemically and radiation-transformed 10T1/2 cell lines. The expression of c-abl, c-fos, c-Ha-ras, and c-myc was growth-related in nontransformed 10T1/2 cells. c-abl and c-fos expression increased at confluence by 5- and 9-fold, respectively, compared to that in log phase cells. c-Ha-ras and c-myc transcripts were most abundant in log phase cells and decreased by 70 and 50%, respectively, in confluent cells. There were no significant growth-related changes in the expression of c-Ha-ras, c-myc, or c-abl in methylcholanthrene-transformed Cl 15 cells. The c-fos transcript was not detected in Cl 15 cell cultures. c-abl, c-fos, c-ras, and c-myc were expressed in whole C3H mouse embryo tissue, mouse liver, and 10T1/2 cells. Sizes of these protooncogene transcripts in 10T1/2 cells were the same as those in whole embryo tissue, except that 10T1/2 cells did not express the 8.2-kilobase abl transcript. At subconfluence, equivalent low levels of c-mos expression were observed in nontransformed and in the eight transformed 10T1/2 cell lines. The level of c-abl expression was similar in the nontransformed and in the eight transformed cell lines, but there was a new 8.2-kilobase transcript in the transformed MCA Cl 15 cell line. c-fos was expressed in 10T1/2 cells but was not detectable or greatly reduced in eight transformed cell lines. c-Ha-ras was expressed to a similar extent in eight transformed cell lines and in nontransformed 10T1/2 cells. In the UVC-4 transformed cell line, extra 3.3-kilobase Ha-ras and 7.5-kilobase Ki-ras transcripts were observed. c-myc was expressed at 4- to 7-fold higher levels in six transformed cell lines compared to 10T1/2 cells.

Shuin, T.; Billings, P.C.; Lillehaug, J.R.; Patierno, S.R.; Roy-Burman, P.; Landolph, J.R.

1986-10-01

50

Establishment of a preadipocyte cell line derived from mature adipocytes of GFP transgenic mice and formation of adipose tissue  

Microsoft Academic Search

We established a preadipocyte cell line from mature adipocytes obtained from subcutaneous fat tissue of green fluorescent\\u000a protein (GFP) transgenic mice. The floating top layer, containing mature adipocytes, was isolated from subcutaneous fat tissue\\u000a by collagenase digestion and filtration. Fluorescence-activated cell sorting and microscopic analysis revealed that the floating\\u000a cell fraction comprised a highly homogeneous adipocyte population with no adipose

Hiroyuki Nobusue; Tsuyoshi Endo; Koichiro Kano

2008-01-01

51

Tubers from potato lines expressing a tomato Kunitz protease inhibitor are substantially equivalent to parental and transgenic controls.  

PubMed

Recombinant protease inhibitors represent useful tools for the development of insect-resistant transgenic crops, but questions have been raised in recent years about the impact of these proteins on endogenous proteases and chemical composition of derived food products. In this study, we performed a detailed compositional analysis of tubers from potato lines expressing the broad-spectrum inhibitor of Ser and Asp proteases, tomato cathepsin D inhibitor (SlCDI), to detect possible unintended effects on tuber composition. A compositional analysis of key nutrients and toxic chemicals was carried out with tubers of SlCDI-expressing and control (comparator) lines, followed by a two-dimensional gel electrophoresis (2-DE) proteomic profiling of total and allergenic proteins to detect eventual effects at the proteome level. No significant differences were observed among control and SlCDI-expressing lines for most chemicals assayed, in line with the very low abundance of SlCDI in tubers. Likewise, proteins detected after 2-DE showed no quantitative variation among the lines, except for a few proteins in some control and test lines, independent of slcdi transgene expression. Components of the patatin storage protein complex and Kunitz protease inhibitors immunodetected after 2-DE showed unaltered deposition patterns in SlCDI-expressing lines, clearly suggesting a null impact of slcdi on the intrinsic allergenic potential of potato tubers. These data suggest, overall, a null impact of slcdi expression on tuber composition and substantial equivalence between comparator and SlCDI-expressing tubers despite reported effects on leaf protein catabolism. They also illustrate the usefulness of proteomics as a tool to assess the authenticity of foods derived from novel-generation transgenic plants. PMID:20051032

Khalf, Moustafa; Goulet, Charles; Vorster, Juan; Brunelle, France; Anguenot, Raphaël; Fliss, Ismaïl; Michaud, Dominique

2010-02-01

52

[Obtaining stem borer-resistant homozygous transgenic lines of Minghui 81 harboring novel cry1Ac gene via particle bombardment].  

PubMed

A modified cry1Ac gene was generated by fusing with Lys-Asp-Glu-Lue (KDEL), an endoplasmic reticulum retention signal at the 3'-ends, with signal peptide coding sequence of Soybean kunitz trypsin inhibitor (SKTI) at the 5'-ends. Vector containing the modified cry1Ac gene coding region flanked by the corn ubiquitin 1 promoter and the nopaline synthase gene (nos) terminator with Hygromycin Phosphotransferase (hpt) gene as a plant selection marker was constructed. The modified cry1Ac gene in which toxic protein targeted to endoplasmic retention was successfully transferred into Minghui 81 (Oryza sativa L. subsp. indica), an elite restoring line of commercial CMS indica hybrid rice, through particle bombardment and obtained fertile transformants. Homozygous transgenic rice lines were obtained in the third generation exploiting self-seed set reproduction and HygromycinB selection. These transgenic lines were confirmed with polymerase chain reaction (PCR) amplification, Southern blotting and ELISA detection. Pest insect-resistant bioassay indicated that some of the homozygous cry1Ac-transgenic rice plants of T2 progeny showed high-level resistance against striped stem borer (Chilo suppressalis) at field trials. PMID:12096630

Zeng, Qian-Chun; Wu, Qian; Zhou, Kai-Da; Feng, De-Jiang; Wang, Feng; Su, Jun; Altosaar, Illimar; Zhu, Zhen

2002-06-01

53

Generation of an ABCG2{sup GFPn-puro} transgenic line - A tool to study ABCG2 expression in mice  

SciTech Connect

The ATP-binding cassette (ABC) transporter 2 (ABCG2) is expressed by stem cells in many organs and in stem cells of solid tumors. These cells are isolated based on the side population (SP) phenotype, a Hoechst 3342 dye efflux property believed to be conferred by ABCG2. Because of the limitations of this approach we generated transgenic mice that express Nuclear GFP (GFPn) coupled to the Puromycin-resistance gene, under the control of ABCG2 promoter/enhancer sequences. We show that ABCG2 is expressed in neural progenitors of the developing forebrain and spinal cord and in embryonic and adult endothelial cells of the brain. Using the neurosphere assay, we isolated tripotent ABCG2-expressing neural stem cells from embryonic mouse brain. This transgenic line is a powerful tool for studying the expression of ABCG2 in many tissues and for performing functional studies in different experimental settings.

Orford, Michael; Mean, Richard; Lapathitis, George; Genethliou, Nicholas; Panayiotou, Elena; Panayi, Helen [The Cyprus Institute of Neurology and Genetics, Airport Avenue, No. 6, Agios Dometios 2370, Nicosia (Cyprus)] [The Cyprus Institute of Neurology and Genetics, Airport Avenue, No. 6, Agios Dometios 2370, Nicosia (Cyprus); Malas, Stavros, E-mail: smalas@cing.ac.cy [The Cyprus Institute of Neurology and Genetics, Airport Avenue, No. 6, Agios Dometios 2370, Nicosia (Cyprus) [The Cyprus Institute of Neurology and Genetics, Airport Avenue, No. 6, Agios Dometios 2370, Nicosia (Cyprus); Department of Biological Sciences, University of Cyprus, P.O. Box 20537, 1678 Nicosia (Cyprus)

2009-06-26

54

Characterization of Multiple Bistratified Retinal Ganglion Cells in A Purkinje Cell Protein 2-Cre Transgenic Mouse Line  

PubMed Central

Retinal ganglion cells are categorized into multiple classes, including multiple types of bistratified ganglion cells (BGCs). The recent use of transgenic mouse lines with specific type(s) of ganglion cells that are labeled by fluorescent markers has facilitated the morphological and physiological studies of BGCs, particularly the directional-selective BGCs. The most important benefit from using transgenic animals is the capability to perform in vivo gene manipulation. In particular, the Cre/LoxP recombination system has become a powerful tool, allowing gene deletion, over-expression, and ectopic expression in a cell type-specific and temporally controlled fashion. The key to this tool is the availability of Cre mouse lines with cell or tissue type-specific expression of Cre recombinase. In this study, we characterized the Cre-positive retinal ganglion cells in a PCP2 (Purkinje cell protein 2)-cre mouse line. We found that all of the Cre-positive retinal ganglion cells were BGCs. Based on morphological criteria, we determined that they can be grouped into five types. The On- and Off-dendrites of three of these types stratified outside of the cholinergic bands and differed from directional selective ganglion cells (DSGCs) morphologically. These cells were negative for Brn-3b and positive for both calretinin and CART retina markers. The remaining two types were identified as putative On-Off and On-DSGCs. This Cre mouse line could be useful for further studies of the molecular and functional properties of BGCs in mice. PMID:23224947

Ivanova, Elena; Lee, Patrick; Pan, Zhuo-Hua

2012-01-01

55

A transgenic mouse line for collecting ribosome-bound mRNA using the tetracycline transactivator system  

PubMed Central

Acquiring the gene expression profiles of specific neuronal cell-types is important for understanding their molecular identities. Genome-wide gene expression profiles of genetically defined cell-types can be acquired by collecting and sequencing mRNA that is bound to epitope-tagged ribosomes (TRAP; translating ribosome affinity purification). Here, we introduce a transgenic mouse model that combines the TRAP technique with the tetracycline transactivator (tTA) system by expressing EGFP-tagged ribosomal protein L10a (EGFP-L10a) under control of the tetracycline response element (tetO-TRAP). This allows both spatial control of EGFP-L10a expression through cell-type specific tTA expression, as well as temporal regulation by inhibiting transgene expression through the administration of doxycycline. We show that crossing tetO-TRAP mice with transgenic mice expressing tTA under the Camk2a promoter (Camk2a-tTA) results in offspring with cell-type specific expression of EGFP-L10a in CA1 pyramidal neurons and medium spiny neurons in the striatum. Co-immunoprecipitation confirmed that EGFP-L10a integrates into a functional ribosomal complex. In addition, collection of ribosome-bound mRNA from the hippocampus yielded the expected enrichment of genes expressed in CA1 pyramidal neurons, as well as a depletion of genes expressed in other hippocampal cell-types. Finally, we show that crossing tetO-TRAP mice with transgenic Fos-tTA mice enables the expression of EGFP-L10a in CA1 pyramidal neurons that are activated during a fear conditioning trial. The tetO-TRAP mouse can be combined with other tTA mouse lines to enable gene expression profiling of a variety of different cell-types.

Drane, Laurel; Ainsley, Joshua A.; Mayford, Mark R.; Reijmers, Leon G.

2014-01-01

56

Cyclin T1Dependent Genes in Activated CD4+ T and Macrophage Cell Lines Appear Enriched in HIV1 Co-Factors  

Microsoft Academic Search

HIV-1 is dependent upon cellular co-factors to mediate its replication cycle in CD4+ T cells and macrophages, the two major cell types infected by the virus in vivo. One critical co-factor is Cyclin T1, a subunit of a general RNA polymerase II elongation factor known as P-TEFb. Cyclin T1 is targeted directly by the viral Tat protein to activate proviral

Wendong Yu; Rajesh Ramakrishnan; Yan Wang; Karen Chiang; Tzu-Ling Sung; Andrew P. Rice

2008-01-01

57

Generation of osteoclast-inductive and osteoclastogenic cell lines from the H-2KbtsA58 transgenic mouse.  

PubMed Central

The development of osteoclastic cell lines would greatly facilitate analysis of the cellular and molecular biology of bone resorption. Several cell lines have previously been reported to be capable of osteoclastic differentiation. However, such cell lines form at best only occasional excavations, suggesting that osteoclastic differentiation is either incomplete or that osteoclasts represent a very small proportion of the cells present. We have used the recently developed H-2KbtsA58 transgenic mouse, in which the interferon-inducible major mouse histocompatibility complex H-2Kb promoter drives the temperature-sensitive (ts) immortalizing gene of simian virus 40 (tsA58), to develop cell lines from bone marrow with high efficiency. Bone marrow cells were incubated with gamma interferon at 33 degrees C, then cloned, and expanded. The cell lines were characterized at 39.5 degrees C in the absence of gamma interferon. First, stromal cell lines were established that induced osteclast formation (resorption of bone slices) when cocultured with hemopoietic spleen cells. Some of the stromal cell lines so generated were able to resorb approximately 30 mm2/cm2 of bone surface. We then established cell lines of hemopoietic origin, several of which possess osteoclastic potential. When these osteoclast-precursor cell lines were cocultured with stromal cell lines, extensive bone resorption was observed. Osteoclast formation did not occur if the precursor cell lines were incubated on bone slices without stromal cells; osteoclast formation was also dependent upon the presence of 1 alpha,25-dihydroxyvitamin D3. These cell lines represent a model for osteoclast formation and a valuable resource for identification of the mechanisms and factors that regulate osteoclast differentiation and function. Images Fig. 2 PMID:8390670

Chambers, T J; Owens, J M; Hattersley, G; Jat, P S; Noble, M D

1993-01-01

58

Inhibitor of DNA-binding 4 contributes to the maintenance and expansion of cancer stem cells in 4T1 mouse mammary cancer cell line  

PubMed Central

The cancer stem cell (CSC) hypothesis proposes that CSCs are the root of cancer. CSC-targeted therapies may prevent cancer relapse and provide more effective treatment. The expression of aldehyde dehydrogenase 1, as assessed by the Aldefluor assay, has been recognized as a marker of CSCs in breast cancer. Inhibitors of DNA-binding proteins (IDs) have an important role in stem cell differentiation. In this study, we examined IDs necessary for the regulation of stem properties in Aldefluorpos 4T1 cells. When the expression profile of IDs in Aldefluorneg and Aldefluorpos 4T1 cells was compared, qRT-PCR analysis showed that ID4 expression was highly upregulated in Aldefluorpos 4T1 cells. In addition, knockdown of ID4 expression suppressed the properties of CSCs, including their sphere-forming ability and side population phenotype. The findings suggest that ID4 may be a therapeutic target for the treatment of advanced breast cancer. PMID:22232642

Park, Se-Jin; Kim, Ran-Ju

2011-01-01

59

Establishment of Transgenic Lines for Jumpstarter Method Using a Composite Transposon Vector in the Ladybird Beetle, Harmonia axyridis  

PubMed Central

In this post-genomic era, genome-wide functional analysis is indispensable. The recent development of RNA interference techniques has enabled researchers to easily analyze gene function even in non-model organisms. On the other hand, little progress has been made in the identification and functional analyses of cis-regulatory elements in non-model organisms. In order to develop experimental platform for identification and analyses of cis-regulatory elements in a non-model organism, in this case, the ladybird beetle, Harmonia axyridis, we established transgenic transposon-tagged lines using a novel composite vector. This vector enables the generation of two types of insertion products (jumpstarter and mutator). The jumpstarter portion carries a transposase gene, while the mutator segment carries a reporter gene for detecting enhancers. The full-composite element is flanked by functional termini (required for movement); however, the mutator region has an extra terminus making it possible for the mutator to remobilize on its own, thus leaving an immobile jumpstarter element behind. Each insertion type is stable on its own, but once crossed, jumpstarters can remobilize mutators. After crossing a jumpstarter and mutator line, all tested G2 females gave rise to at least one new insertion line in the next generation. This jumping rate is equivalent to the P-element-mediated jumpstarter method in Drosophila. These established transgenic lines will offer us the ideal experimental materials for the effective screening and identification of enhancers in this species. In addition, this jumpstarter method has the potential to be as effective in other non-model insect species and thus applicable to any organism. PMID:24959904

Kuwayama, Hisashi; Gotoh, Hiroki; Konishi, Yusuke; Nishikawa, Hideto; Yaginuma, Toshinobu; Niimi, Teruyuki

2014-01-01

60

Megaesophagus in a line of transgenic rats: a model of achalasia.  

PubMed

Megaesophagus is defined as the abnormal enlargement or dilatation of the esophagus, characterized by a lack of normal contraction of the esophageal walls. This is called achalasia when associated with reduced or no relaxation of the lower esophageal sphincter (LES). To date, there are few naturally occurring models for this disease. A colony of transgenic (Pvrl3-Cre) rats presented with megaesophagus at 3 to 4 months of age; further breeding studies revealed a prevalence of 90% of transgene-positive animals having megaesophagus. Affected rats could be maintained on a total liquid diet long term and were shown to display the classic features of dilated esophagus, closed lower esophageal sphincter, and abnormal contractions on contrast radiography and fluoroscopy. Histologically, the findings of muscle degeneration, inflammation, and a reduced number of myenteric ganglia in the esophagus combined with ultrastructural lesions of muscle fiber disarray and mitochondrial changes in the striated muscle of these animals closely mimic that seen in the human condition. Muscle contractile studies looking at the response of the lower esophageal sphincter and fundus to electrical field stimulation, sodium nitroprusside, and L-nitro-L-arginine methyl ester also demonstrate the similarity between megaesophagus in the transgenic rats and patients with achalasia. No primary cause for megaesophagus was found, but the close parallel to the human form of the disease, as well as ease of care and manipulation of these rats, makes this a suitable model to better understand the etiology of achalasia as well as study new management and treatment options for this incurable condition. PMID:24457157

Pang, J; Borjeson, T M; Muthupalani, S; Ducore, R M; Carr, C A; Feng, Y; Sullivan, M P; Cristofaro, V; Luo, J; Lindstrom, J M; Fox, J G

2014-11-01

61

Establishment of a Transgenic Zebrafish Line for Superficial Skin Ablation and Functional Validation of Apoptosis Modulators In Vivo  

PubMed Central

Background Zebrafish skin is composed of enveloping and basal layers which form a first-line defense system against pathogens. Zebrafish epidermis contains ionocytes and mucous cells that aid secretion of acid/ions or mucous through skin. Previous studies demonstrated that fish skin is extremely sensitive to external stimuli. However, little is known about the molecular mechanisms that modulate skin cell apoptosis in zebrafish. Methodology/Principal Findings This study aimed to create a platform to conduct conditional skin ablation and determine if it is possible to attenuate apoptotic stimuli by overexpressing potential apoptosis modulating genes in the skin of live animals. A transgenic zebrafish line of Tg(krt4:NTR-hKikGR)cy17 (killer line), which can conditionally trigger apoptosis in superficial skin cells, was first established. When the killer line was incubated with the prodrug metrodinazole, the superficial skin displayed extensive apoptosis as judged by detection of massive TUNEL- and active caspase 3-positive signals. Great reductions in NTR-hKikGR+ fluorescent signals accompanied epidermal cell apoptosis. This indicated that NTR-hKikGR+ signal fluorescence can be utilized to evaluate apoptotic events in vivo. After removal of metrodinazole, the skin integrity progressively recovered and NTR-hKikGR+ fluorescent signals gradually restored. In contrast, either crossing the killer line with testing lines or transiently injecting the killer line with testing vectors that expressed human constitutive active Akt1, mouse constitutive active Stat3, or HPV16 E6 element displayed apoptosis-resistant phenotypes to cytotoxic metrodinazole as judged by the loss of reduction in NTR-hKikGR+ fluorescent signaling. Conclusion/Significance The killer/testing line binary system established in the current study demonstrates a nitroreductase/metrodinazole system that can be utilized to conditionally perform skin ablation in a real-time manner, and provides a valuable tool to visualize and quantify the anti-apoptotic potential of interesting target genes in vivo. The current work identifies a potential use for transgenic zebrafish as a high-throughput platform to validate potential apoptosis modulators in vivo. PMID:21655190

Chen, Chi-Fang; Chu, Che-Yu; Chen, Te-Hao; Lee, Shyh-Jye; Shen, Chia-Ning; Hsiao, Chung-Der

2011-01-01

62

Protamine-Cre recombinase transgenes efficiently recombine target sequences in the male germ line of mice, but not in embryonic stem cells  

Microsoft Academic Search

The production of subtle or conditional mu- tations in mice through the combined use of site-specific and homologous recombination has become an increasingly wide- spread experimental paradigm in mammalian genetics. Em- bryonic stem cells containing recombinase transgenes that were expressed in the male germ line, but not in other tissues or in the embryonic stem cells themselves, would substantially simplify

STEPHEN O'GORMAN; NICOLE A. DAGENAIS; YELENA MARCHUK

1997-01-01

63

Nutritional properties of tubers of conventionally bred and transgenic lines of potato resistant to necrotic strain of Potato virus Y (PVYN)  

Microsoft Academic Search

The potential effect of genetic modification on nutritional properties of potatoes transformed to improve resistance to a necrotic strain of Potato virus Y was determined in a rat experiment. Autoclaved tubers from four transgenic lines were included to a diet in the amount of 40% and compared with the conventional cv. Irga. The experiment lasted 3 weeks and special aention

Józef Fornal

64

Embryonal subregion-derived stromal cell lines from novel temperature-sensitive SV40 T antigen transgenic mice support hematopoiesis.  

PubMed

Throughout life, the hematopoietic system requires a supportive microenvironment that allows for the maintenance and differentiation of hematopoietic stem cells (HSC). To understand the cellular interactions and molecules that provide these functions, investigators have previously established stromal cell lines from the late gestational stage and adult murine hematopoietic microenvironments. However, the stromal cell microenvironment that supports the emergence, expansion and maintenance of HSCs during mid-gestational stages has been largely unexplored. Since several tissues within the mouse embryo are known to harbor HSCs (i.e. aortagonads-mesonephros, yolk sac, liver), we generated numerous stromal cell clones from these mid-gestational sites. Owing to the limited cell numbers, isolations were performed with tissues from transgenic embryos containing the ts SV40 Tag gene (tsA58) under the transcriptional control of constitutive and ubiquitously expressing promoters. We report here that the growth and cloning efficiency of embryonic cells (with the exception of the aorta) is increased in the presence of the tsA58 transgene. Furthermore, our results show that the large panel of stromal clones isolated from the different embryonal subregions exhibit heterogeneity in their ability to promote murine and human hematopoietic differentiation. Despite our findings of heterogeneity in hematopoietic growth factor gene expression profiles, high-level expression of some factors may influence hematopoietic differentiation. Interestingly, a few of these stromal clones express a recently described chordin-like protein, which is an inhibitor of bone morphogenic proteins and is preferentially expressed in cells of the mesenchymal lineage. PMID:11973351

Oostendorp, Robert A J; Medvinsky, Alexander J; Kusadasi, Nuray; Nakayama, Naoki; Harvey, Kirsty; Orelio, Claudia; Ottersbach, Katrin; Covey, Todd; Ploemacher, Rob E; Saris, Chris; Dzierzak, Elaine

2002-05-15

65

Effect of vegetation of transgenic Bt rice lines and their straw amendment on soil enzymes, respiration, functional diversity and community structure of soil microorganisms under field conditions.  

PubMed

With the development of transgenic crops, there is an increasing concern about the possible adverse effects of their vegetation and residues on soil environmental quality. This study was carried out to evaluate the possible effects of the vegetation of transgenic Bt rice lines Huachi B6 (HC) and TT51 (TT) followed by the return of their straw to the soil on soil enzymes (catalase, urease, neutral phosphatase and invertase), anaerobic respiration activity, microbial utilization of carbon substrates and community structure, under field conditions. The results indicated that the vegetation of the two transgenic rice lines (HC and TT) and return of their straw had few adverse effects on soil enzymes and anaerobic respiration activity compared to their parent and distant parent, although some transient differences were observed. The vegetation and subsequent straw amendment of Bt rice HC and TT did not appear to have a harmful effect on the richness, evenness and community structure of soil microorganisms. No different pattern of impact due to plant species was found between HC and TT. It could be concluded that the vegetation of transgenic Bt rice lines and the return of their straw as organic fertilizer may not alter soil microbe-mediated functions. PMID:23513447

Fang, Hua; Dong, Bin; Yan, Hu; Tang, Feifan; Wang, Baichuan; Yu, Yunlong

2012-01-01

66

Generation of hermaphrodite transgenic papaya lines with virus resistance via transformation of somatic embryos derived from adventitious roots of in vitro shoots.  

PubMed

Papaya production is seriously limited by Papaya ringspot virus (PRSV) worldwide and Papaya leaf-distortion mosaic virus (PLDMV) in Eastern Asia. An efficient transformation method for developing papaya lines with transgenic resistance to these viruses and commercially desirable traits, such as hermaphroditism, is crucial to shorten the breeding program for this fruit crop. In this investigation, an untranslatable chimeric construct pYP08 containing truncated PRSV coat protein (CP) and PLDMV CP genes coupled with the 3' untranslational region of PLDMV, was generated. Root segments from different portions of adventitious roots of in vitro multiple shoots of hermaphroditic plants of papaya cultivars 'Tainung No. 2', 'Sunrise', and 'Thailand' were cultured on induction medium for regeneration into somatic embryos. The highest frequency of somatic embryogenesis was from the root-tip segments of adventitious roots developed 2-4 weeks after rooting in perlite medium. After proliferation, embryogenic tissues derived from somatic embryos were wounded in liquid-phase by carborundum and transformed by Agrobacterium carrying pYP08. Similarly, another construct pBG-PLDMVstop containing untranslatable CP gene of PLDMV was also transferred to 'Sunrise' and 'Thailand', the parental cultivars of 'Tainung No. 2'. Among 107 transgenic lines regenerated from 349 root-tip segments, nine lines of Tainung No. 2 carrying YP08 were highly resistant to PRSV and PLDMV, and 9 lines (8 'Sunrise' and 1 'Thailand') carrying PLDMV CP highly resistant to PLDMV, by a mechanism of post-transcriptional gene silencing. The hermaphroditic characteristics of the transgenic lines were confirmed by PCR with sex-linked primers and phenotypes of flower and fruit. Our approach has generated transgenic resistance to both PRSV and PLDMV with commercially desirable characters and can significantly shorten the time-consuming breeding programs for the generation of elite cultivars of papaya hybrids. PMID:19943109

Kung, Yi-Jung; Yu, Tsong-Ann; Huang, Chiung-Huei; Wang, Hui-Chin; Wang, Shin-Lan; Yeh, Shyi-Dong

2010-08-01

67

High throughput generation of promoter reporter (GFP) transgenic lines of low expressing genes in Arabidopsis and analysis of their expression patterns  

PubMed Central

Background Although the complete genome sequence and annotation of Arabidopsis were released at the end of year 2000, it is still a great challenge to understand the function of each gene in the Arabidopsis genome. One way to understand the function of genes on a genome-wide scale is expression profiling by microarrays. However, the expression level of many genes in Arabidopsis genome cannot be detected by microarray experiments. In addition, there are many more novel genes that have been discovered by experiments or predicted by new gene prediction programs. Another way to understand the function of individual genes is to investigate their in vivo expression patterns by reporter constructs in transgenic plants which can provide basic information on the patterns of gene expression. Results A high throughput pipeline was developed to generate promoter-reporter (GFP) transgenic lines for Arabidopsis genes expressed at very low levels and to examine their expression patterns in vivo. The promoter region from a total of 627 non- or low-expressed genes in Arabidopsis based on Arabidopsis annotation release 5 were amplified and cloned into a Gateway vector. A total of 353 promoter-reporter (GFP) constructs were successfully transferred into Agrobacterium (GV3101) by triparental mating and subsequently used for Arabidopsis transformation. Kanamycin-resistant transgenic lines were obtained from 266 constructs and among them positive GFP expression was detected from 150 constructs. Of these 150 constructs, multiple transgenic lines exhibiting consistent expression patterns were obtained for 112 constructs. A total 81 different regions of expression were discovered during our screening of positive transgenic plants and assigned Plant Ontology (PO) codes. Conclusions Many of the genes tested for which expression data were lacking previously are indeed expressed in Arabidopsis during the developmental stages screened. More importantly, our study provides plant researchers with another resource of gene expression information in Arabidopsis. The results of this study are captured in a MySQL database and can be searched at http://www.jcvi.org/arabidopsis/qpcr/index.shtml. Transgenic seeds and constructs are also available for the research community. PMID:20687964

2010-01-01

68

Generation and characterization of Tbx1-AmCyan1 transgenic reporter mouse line that selectively labels developing thymus primordium.  

PubMed

Thymus development is a complicated process that includes highly dynamic morphological changes and reciprocal tissue interactions between endoderm-derived epithelial cells of the anterior foregut and neural crest-derived mesenchymal cells. We generated and characterized a Tbx1-AmCyan1 reporter transgenic mouse to visualize thymus precursor cells during early embryonic development. In transgenic embryos, AmCyan1 fluorescence was specifically detected in the endoderm of the developing 3rd and 4th pharyngeal pouches and later in thymus epithelium until E14.5. Cells expressing AmCyan1 that were isolated based on AmCyan1 fluorescence expressed endodermal, thymic, and parathyroid markers, but they did not express neural crest or endothelial markers; these findings indicated that this transgenic mouse strain could be used to collect thymic or parathyroid precursor cells or both. We also showed that in nude mice, which exhibit defects in thymus development, the thymus precursors were clearly labeled with AmCyan1. In summary, these AmCyan1-fluorescent transgenic mice are useful for investigating early thymus development. PMID:23117587

Kimura, Wataru; Sharkar, Mohammad Tofael Kabir; Sultana, Nishat; Islam, Mohammod Johirul; Uezato, Tadayoshi; Miura, Naoyuki

2013-06-01

69

Transgenic pearl millet male fertility restorer line (ICMP451) and hybrid (ICMH451) expressing Brassica juncea Nonexpressor of pathogenesis related genes 1 (BjNPR1) exhibit resistance to downy mildew disease.  

PubMed

Brassica juncea Nonexpressor of pathogenesis-related genes 1 (BjNPR1) has been introduced into pearl millet male fertility restorer line ICMP451 by Agrobacterium tumefaciens-mediated genetic transformation. Transgenic pearl millet plants were regenerated from the phosphinothricin-resistant calli obtained after co-cultivation with A. tumefaciens strain LBA4404 harbouring Ti plasmid pSB111-bar-BjNPR1. Molecular analyses confirmed the stable integration and expression of BjNPR1 in transgenic pearl millet lines. Transgenes BjNPR1 and bar were stably inherited and disclosed co-segregation in subsequent generations in a Mendelian fashion. Transgenic pearl millet hybrid ICMH451-BjNPR1 was developed by crossing male-sterile line 81A X homozygous transgenic line ICMP451-BjNPR1. T3 and T4 homozygous lines of ICMP451-BjNPR1 and hybrid ICMH451-BjNPR1 exhibited resistance to three strains of downy mildew pathogen, while the untransformed ICMP451 and the isogenic hybrid ICMH451 plants were found susceptible. Following infection with S. graminicola, differential expression of systemic acquired resistance pathway genes, UDP-glucose salicylic acid glucosyl transferase and pathogenesis related gene 1 was observed in transgenic ICMP451-BjNPR1 and untransformed plants indicating the activation of systemic acquired resistance pathway contributing to the transgene-mediated resistance against downy mildew. The transgenic pearl millet expressing BjNPR1 showed resistance to multiple strains of S. graminicola and, as such, seems promising for the development of durable downy mildew resistant hybrids. PMID:24603762

Ramineni, Ramadevi; Sadumpati, Vijayakumar; Khareedu, Venkateswara Rao; Vudem, Dashavantha Reddy

2014-01-01

70

Transgenic Pearl Millet Male Fertility Restorer Line (ICMP451) and Hybrid (ICMH451) Expressing Brassica juncea Nonexpressor of Pathogenesis Related Genes 1 (BjNPR1) Exhibit Resistance to Downy Mildew Disease  

PubMed Central

Brassica juncea Nonexpressor of pathogenesis-related genes 1 (BjNPR1) has been introduced into pearl millet male fertility restorer line ICMP451 by Agrobacterium tumefaciens-mediated genetic transformation. Transgenic pearl millet plants were regenerated from the phosphinothricin-resistant calli obtained after co-cultivation with A. tumefaciens strain LBA4404 harbouring Ti plasmid pSB111-bar-BjNPR1. Molecular analyses confirmed the stable integration and expression of BjNPR1 in transgenic pearl millet lines. Transgenes BjNPR1 and bar were stably inherited and disclosed co-segregation in subsequent generations in a Mendelian fashion. Transgenic pearl millet hybrid ICMH451-BjNPR1 was developed by crossing male-sterile line 81A X homozygous transgenic line ICMP451-BjNPR1. T3 and T4 homozygous lines of ICMP451-BjNPR1 and hybrid ICMH451-BjNPR1 exhibited resistance to three strains of downy mildew pathogen, while the untransformed ICMP451 and the isogenic hybrid ICMH451 plants were found susceptible. Following infection with S. graminicola, differential expression of systemic acquired resistance pathway genes, UDP-glucose salicylic acid glucosyl transferase and pathogenesis related gene 1 was observed in transgenic ICMP451-BjNPR1 and untransformed plants indicating the activation of systemic acquired resistance pathway contributing to the transgene-mediated resistance against downy mildew. The transgenic pearl millet expressing BjNPR1 showed resistance to multiple strains of S. graminicola and, as such, seems promising for the development of durable downy mildew resistant hybrids. PMID:24603762

Khareedu, Venkateswara Rao; Vudem, Dashavantha Reddy

2014-01-01

71

Salicylic acid deficiency in NahG transgenic lines and sid2 mutants increases seed yield in the annual plant Arabidopsis thaliana  

PubMed Central

Salicylic acid-deficient NahG transgenic lines and sid2 mutants were used to evaluate the role of this compound in the development of the short-lived, annual plant Arabidopsis thaliana, with a particular focus on the interplay between salicylic acid and other phytohormones. Low salicylic acid levels led to increased growth, as well as to smaller abscisic acid levels and reduced damage to PSII (as indicated by Fv/Fm ratios) during the reproductive stages in rosette leaves of NahG transgenic lines and sid2 mutants, compared with wild-type plants. Furthermore, salicylic acid deficiency highly influenced seed yield and composition. Seed production increased by 4.4-fold and 3.5-fold in NahG transgenic lines and sid2 mutants, respectively, compared to the wild type. Salicylic acid deficiency also improved seed composition in terms of antioxidant vitamin concentrations, seeds of salicylic acid-deficient plants showing higher levels of ?- and ?-tocopherol (vitamin E) and ?-carotene (pro-vitamin A) than seeds of wild-type plants. Seeds of salicylic acid-deficient plants also showed higher nitrogen concentrations than seeds of wild-type plants. It is concluded that (i) the sid2 gene, which encodes for isochorismate synthase, plays a central role in salicylic acid biosynthesis during plant development in A. thaliana, (ii) salicylic acid plays a role in the regulation of growth, senescence, and seed production, (iii) there is a cross-talk between salicylic acid and other phytohormones during plant development, and (iv) the concentrations of antioxidant vitamins in seeds may be influenced by the endogenous levels of salicylic acid in plants. PMID:19188277

Abreu, Maria Elizabeth; Munne-Bosch, Sergi

2009-01-01

72

Transgenic zebrafish line with over-expression of Hedgehog on the skin: a useful tool to screen Hedgehog-inhibiting compounds  

Microsoft Academic Search

We generated a transgenic line Tg(k18:shh:RFP) with overexpression of Sonic hedgehog in the skin epidermis. By 5 day-post-fertilization (dpf), many epidermal lesions were\\u000a clearly observed, including a swollen yolk sac, epidermis growth malformation around the eyes and at the basement of the pectoral\\u000a fins. Skin histology revealed embryos derived from Tg(k18:shh:RFP) displayed an elevated Nuclear\\/Cytoplasmic ratio and pleomorphic nuclei compared to

Yau-Hung Chen; Yun-Hsin Wang; Tsung-Han Yu; Hsin-Ju Wu; Chiung-Wen Pai

2009-01-01

73

Enhanced resistance to stripe rust disease in transgenic wheat expressing the rice chitinase gene RC24.  

PubMed

Stripe rust is a devastating fungal disease of wheat worldwide which is primarily caused by Puccinia striiformis f. sp tritici. Transgenic wheat (Triticum aestivum L.) expressing rice class chitinase gene RC24 were developed by particle bombardment of immature embryos and tested for resistance to Puccinia striiformis f.sp tritici. under greenhouse and field conditions. Putative transformants were selected on kanamycin-containing media. Polymease chain reaction indicated that RC24 was transferred into 17 transformants obtained from bombardment of 1,684 immature embryos. Integration of RC24 was confirmed by Southern blot with a RC24-labeled probe and expression of RC24 was verified by RT-PCR. Nine transgenic T1 lines exhibited enhanced resistance to stripe rust infection with lines XN8 and BF4 showing the highest level of resistance. Southern blot hybridization confirmed the stable inheritance of RC24 in transgenic T1 plants. Resistance to stripe rust in transgenic T2 and T3 XN8 and BF4 plants was confirmed over two consecutive years in the field. Increased yield (27-36 %) was recorded for transgenic T2 and T3 XN8 and BF4 plants compared to controls. These results suggest that rice class I chitinase RC24 can be used to engineer stripe rust resistance in wheat. PMID:23529204

Huang, Xuan; Wang, Jian; Du, Zhen; Zhang, Chen; Li, Lan; Xu, Ziqin

2013-10-01

74

Effects of defoliating insect resistance QTLs and a cry1Ac transgene in soybean near-isogenic lines  

Microsoft Academic Search

The crystal proteins coded by transgenes from Bacillus thuringiensis (Bt) have shown considerable value in providing effective insect resistance in a number of crop species, including soybean,\\u000a Glycine max (L.) Merr. Additional sources of soybean insect resistance would be desirable to manage the development of tolerance\\/resistance\\u000a to crystal proteins by defoliating insects and to sustain the deployment of Bt crops.

S. Zhu; D. R. Walker; H. R. Boerma; W. A. Parrott

2008-01-01

75

[Transgenic wheat (Triticum aestivum L.) with increased resistance to the storage pest obtained by Agrobacterium tumefaciens--mediated].  

PubMed

The transgenic wheat of improved resistance to the storage pest was production. We have introduced the cowpea trypsin inhibitor gene (CpTI) into cultured embryonic callus cells of immature embryos of wheat elite line by Agrobacterium-mediated method. Independent plantlets were obtained from the kanamycin-resistant calli after screening. PCR and real time PCR analysis, PCR-Southern and Southern blot hybridization indicated that there were 3 transgenic plants viz. transformed- I, II and III (T- I, T-II and T-III). The transformation frequencies were obviously affected by Agrobacterium concentration, the infection duration and transformation treatment. The segregations of CpTI in the transgenic wheat progenies were not easily to be elucidated, and some transgenic wheat lines (T- I and T-III) showed Mendelian segregations. The determinations of insect resistance to the stored grain insect of wheat viz. the grain moth (Sitotroga cerealella Olivier) indicated that the 3 transgenic wheat progeny seeds moth-resistance was improved significantly. The seed moth-eaten ratio of T- I, T-II, T-III and nontransformed control was 19.8%, 21.9%, 32.9% and 58.3% respectively. 3 transgenic wheat T1 PCR-positive plants revealed that the 3 transgenic lines had excellent agronomic traits. They supplied good germplasm resource of insect-resistance for wheat genetic improvement. PMID:16755923

Bi, Rui-Ming; Jia, Hai-Yan; Feng, De-Shun; Wang, Hong-Gang

2006-05-01

76

Synergistic effect of human CycT1 and CRM1 on HIV-1 propagation in rat T cells and macrophages  

PubMed Central

Background In vivo studies of HIV-1 pathogenesis and testing of antiviral strategies have been hampered by the lack of an immunocompetent small animal model that is highly susceptible to HIV-1 infection. Although transgenic rats that express the HIV-1 receptor complex hCD4 and hCCR5 are susceptible to infection, HIV-1 replicates very poorly in these animals. To demonstrate the molecular basis for developing a better rat model for HIV-1 infection, we evaluated the effect of human CyclinT1 (hCycT1) and CRM1 (hCRM1) on Gag p24 production in rat T cells and macrophages using both established cell lines and primary cells prepared from hCycT1/hCRM1 transgenic rats. Results Expression of hCycT1 augmented Gag production 20–50 fold in rat T cells, but had little effect in macrophages. Expression of hCRM1 enhanced Gag production 10–15 fold in macrophages, but only marginally in T cells. Expression of both factors synergistically enhanced p24 production to levels approximately 10–40% of those detected in human cells. R5 viruses produced in rat T cells and macrophages were fully infectious. Conclusion The expression of both hCycT1 and hCRM1 appears to be fundamental to developing a rat model that supports robust propagation of HIV-1. PMID:19435492

Okada, Hiroyuki; Zhang, Xianfeng; Ben Fofana, Ismael; Nagai, Mika; Suzuki, Hajime; Ohashi, Takashi; Shida, Hisatoshi

2009-01-01

77

SirT1 Regulates Adipose Tissue Inflammation  

PubMed Central

OBJECTIVE Macrophage recruitment to adipose tissue is a reproducible feature of obesity. However, the events that result in chemokine production and macrophage recruitment to adipose tissue during states of energetic excess are not clear. Sirtuin 1 (SirT1) is an essential nutrient-sensing histone deacetylase, which is increased by caloric restriction and reduced by overfeeding. We discovered that SirT1 depletion causes anorexia by stimulating production of inflammatory factors in white adipose tissue and thus posit that decreases in SirT1 link overnutrition and adipose tissue inflammation. RESEARCH DESIGN AND METHODS We used antisense oligonucleotides to reduce SirT1 to levels similar to those seen during overnutrition and studied SirT1-overexpressing transgenic mice and fat-specific SirT1 knockout animals. Finally, we analyzed subcutaneous adipose tissue biopsies from two independent cohorts of human subjects. RESULTS We found that inducible or genetic reduction of SirT1 in vivo causes macrophage recruitment to adipose tissue, whereas overexpression of SirT1 prevents adipose tissue macrophage accumulation caused by chronic high-fat feeding. We also found that SirT1 expression in human subcutaneous fat is inversely related to adipose tissue macrophage infiltration. CONCLUSIONS Reduction of adipose tissue SirT1 expression, which leads to histone hyperacetylation and ectopic inflammatory gene expression, is identified as a key regulatory component of macrophage influx into adipose tissue during overnutrition in rodents and humans. Our results suggest that SirT1 regulates adipose tissue inflammation by controlling the gain of proinflammatory transcription in response to inducers such as fatty acids, hypoxia, and endoplasmic reticulum stress. PMID:22110092

Gillum, Matthew P.; Kotas, Maya E.; Erion, Derek M.; Kursawe, Romy; Chatterjee, Paula; Nead, Kevin T.; Muise, Eric S.; Hsiao, Jennifer J.; Frederick, David W.; Yonemitsu, Shin; Banks, Alexander S.; Qiang, Li; Bhanot, Sanjay; Olefsky, Jerrold M.; Sears, Dorothy D.; Caprio, Sonia; Shulman, Gerald I.

2011-01-01

78

Establishment of transgenic lines to monitor and manipulate Yap/Taz-Tead activity in zebrafish reveals both evolutionarily conserved and divergent functions of the Hippo pathway.  

PubMed

To investigate the role of Hippo pathway signaling during vertebrate development transgenic zebrafish lines were generated and validated to dynamically monitor and manipulate Yap/Taz-Tead activity. Spatial and temporal analysis of Yap/Taz-Tead activity suggested the importance of Hippo signaling during cardiac precursor migration and other developmental processes. When the transcriptional co-activators, Yap and Taz were restricted from interacting with DNA-binding Tead transcription factors through expression of a dominant negative transgene, cardiac precursors failed to migrate completely to the midline resulting in strong cardia bifida. Yap/Taz-Tead activity reporters also allowed us to investigate upstream and downstream factors known to regulate Hippo signaling output in Drosophila. While Crumbs mutations in Drosophila eye disc epithelia increase nuclear translocation and activity of Yorkie (the fly homolog of Yap/Taz), zebrafish crb2a mutants lacked nuclear Yap positive cells and down-regulated Yap/Taz-Tead activity reporters in the eye epithelia, despite the loss of apical-basal cell polarity in those cells. However, as an example of evolutionary conservation, the Tondu-domain containing protein Vestigial-like 4b (Vgll4b) was found to down-regulate endogenous Yap/Taz-Tead activity in the retinal pigment epithelium, similar to Drosophila Tgi in imaginal discs. In conclusion, the Yap/Taz-Tead activity reporters revealed the dynamics of Yap/Taz-Tead signaling and novel insights into Hippo pathway regulation for vertebrates. These studies highlight the utility of this transgenic tool-suite for ongoing analysis into the mechanisms of Hippo pathway regulation and the consequences of signaling output. PMID:24560909

Miesfeld, Joel B; Link, Brian A

2014-08-01

79

Relative transgene expression frequencies in homozygous versus hemizygous transgenic mice.  

PubMed

We have used a simple binomial model of stochastic transgene inactivation at the level of the chromosome or transgene, rather than the cellular level, for the analysis of two mouse transgenic lines that show variegated patterns of expression. This predicts the percentages of cells that express one, both or neither alleles of the transgene in homozygotes from the observed percentages of cells, which express the transgene in hemizygotes. It adequately explained the relationship between the numbers of cells expressing the transgene in hemizygous and homozygous mosaic 21OH/LacZ mouse adrenals and mosaic BLG/7 mouse mammary glands. The binomial model also predicted that a small proportion of cells in mosaic mammary glands of BLG/7 homozygotes would express both BLG/7 alleles but published data indicated that all cells expressing the transgene showed monoallelic expression. Although it didn't fit all of the BLG/7 data as precisely as a more complex model, which used several ad hoc assumptions to explain these results, the simple binomial model was able to explain the relationship in observed transgene expression frequencies between hemizygous and homozygous mosaic tissues for both 21OH/LacZ and BLG/7 mice. It may prove to be a useful general model for analysing other transgenic animals showing mosaic transgene expression. PMID:23873612

Chang, Su-Ping; Opsahl, Margaret L; Whitelaw, C Bruce A; Morley, Steven D; West, John D

2013-12-01

80

Agrobacterium-mediated transformation of safflower and the efficient recovery of transgenic plants via grafting  

PubMed Central

Background Safflower (Carthamus tinctorius L.) is a difficult crop to genetically transform being susceptible to hyperhydration and poor in vitro root formation. In addition to traditional uses safflower has recently emerged as a broadacre platform for the production of transgenic products including modified oils and pharmaceutically active proteins. Despite commercial activities based on the genetic modification of safflower, there is no method available in the public domain describing the transformation of safflower that generates transformed T1 progeny. Results An efficient and reproducible protocol has been developed with a transformation efficiency of 4.8% and 3.1% for S-317 (high oleic acid content) and WT (high linoleic acid content) genotypes respectively. An improved safflower transformation T-DNA vector was developed, including a secreted GFP to allow non-destructive assessment of transgenic shoots. Hyperhydration and necrosis of Agrobacterium-infected cotyledons was effectively controlled by using iota-carrageenan, L-cysteine and ascorbic acid. To overcome poor in vitro root formation for the first time a grafting method was developed for safflower in which ~50% of transgenic shoots develop into mature plants bearing viable transgenic T1 seed. The integration and expression of secreted GFP and hygromycin genes were confirmed by PCR, Southern and Western blot analysis. Southern blot analysis in nine independent lines indicated that 1-7 transgenes were inserted per line and T1 progeny displayed Mendelian inheritance. Conclusions This protocol demonstrates significant improvements in both the efficiency and ease of use over existing safflower transformation protocols. This is the first complete method of genetic transformation of safflower that generates stably-transformed plants and progeny, allowing this crop to benefit from modern molecular applications. PMID:21595986

2011-01-01

81

Neuropathological changes in two lines of mice carrying a transgene for mutant human Cu,Zn SOD, and in mice overexpressing wild type human SOD: a model of familial amyotrophic lateral sclerosis (FALS)  

Microsoft Academic Search

Two different lines of mice, G1 and G20, carrying a transgene for a mutant form of Cu,Zn SOD, found in a family with familial amyotrophic lateral sclerosis (FALS), develop clinical and pathological changes which are, in their late stages, strikingly similar to those in human disease. We have analyzed the distribution and characteristics of lesions in the central and peripheral

Mauro C. Dal Canto; Mark E. Gurney

1995-01-01

82

Development of a Convenient In Vivo Hepatotoxin Assay Using a Transgenic Zebrafish Line with Liver-Specific DsRed Expression  

PubMed Central

Previously we have developed a transgenic zebrafish line (LiPan) with liver-specific red fluorescent protein (DsRed) expression under the fabp10a promoter. Since red fluorescence in the liver greatly facilitates the observation of liver in live LiPan fry, we envision that the LiPan zebrafish may provide a useful tool in analyses of hepatotoxicity based on changes of liver red fluorescence intensity and size. In this study, we first tested four well-established hepatotoxins (acetaminophen, aspirin, isoniazid and phenylbutazone) in LiPan fry and demonstrated that these hepatotoxins could significantly reduce both liver red fluorescence and liver size in a dosage-dependent manner, thus the two measurable parameters could be used as indicators of hepatotoxicity. We then tested the LiPan fry with nine other chemicals including environmental toxicants and human drugs. Three (mefenamic acid, lindane, and arsenate) behave like hepatotoxins in reduction of liver red fluorescence, while three others (17?-estradiol, TCDD [2,3,7,8-tetrachlorodibenzo-p-dioxin] and NDMA [N-nitrosodimethylamine]) caused increase of liver red fluorescence and the liver size. Ethanol and two other chemicals, amoxicillin (antibiotics) and chlorphenamine (pain killer) did not resulted in significant changes of liver red fluorescence and liver size. By quantitative RT-PCR analysis, we found that the changes of red fluorescence intensity caused by different chemicals correlated to the changes of endogenous fabp10a RNA expression, indicating that the measured hepatotoxicity was related to fatty acid transportation and metabolism. Finally we tested a mixture of four hepatotoxins and observed a significant reduction of red fluorescence in the liver at concentrations below the lowest effective concentrations of individual hepatotoxins, suggesting that the transgenic zebrafish assay is capable of reporting compound hepatotoxicity effect from chemical mixtures. Thus, the LiPan transgenic fry provide a rapid and convenient in vivo hepatotoxicity assay that should be applicable to high-throughput hepatotoxicity test in drug screening as well as in biomonitoring environmental toxicants. PMID:24626481

Zhang, Xiaoyan; Li, Caixia; Gong, Zhiyuan

2014-01-01

83

Digestive utilization of phosphorus from plant-based diets in the Cassie line of transgenic Yorkshire pigs that secrete phytase in the saliva.  

PubMed

A line of transgenic Yorkshire pigs referred to as the Cassie (CA) line was generated, which possessed a stable, low copy number phytase transgene insertion that enabled phytase secretion in the saliva. This study was conducted to assess growth and efficacy for improving P, Ca, and other macromineral utilization in the CA pigs receiving diets typical of those used for commercial swine production. In Exp. 1, 12 CA boars and 12 CA gilts fed diets without supplemental P gained weight and exhibited feed efficiency similar to conventional age-matched 12 Yorkshire boars and 12 Yorkshire gilts raised on similar diets with supplemental P. Serum concentrations of P and Ca were similar for CA and Yorkshire pigs during the growing and finishing phases, indicating that the CA pigs were not P limited. In Exp. 2, 6 CA (13.1 kg BW) and 6 Yorkshire barrows (8.8 kg BW) were fed 3 diets (control; low in Ca and P; and low in Ca, P, and CP) over 3 phases. The CA barrows fed the diet without supplemental P retained 25 to 40% (P < 0.001), 77 to 91% (P < 0.001), and 27 to 56% (P < 0.001) more P during the weaning, growing, and finishing phases, respectively, than conventional Yorkshire barrows fed similar diets without supplemental P. In Exp. 3, CA and Yorkshire barrows of similar ages weighing 66.2 ± 1.7 kg (n = 10) and 50.0 ± 1.0 kg (n = 10), respectively, were used. The P retention of CA finisher barrows fed a diet without supplemental P was 34% greater (P < 0.001) than conventional Yorkshire barrows fed the same diet with 750 units of exogenous phytase/kg diet. Urinary Ca to P ratio in the CA pigs was 0.27, whereas that for the Yorkshire barrows was 30, thereby, indicating that the Yorkshire barrows suffered a P deficiency. Furthermore, digestive utilization of major electrolyte macrominerals, K and Na, was improved (P < 0.05) by 18 and 16%, respectively, in the CA finisher pigs compared with the conventional Yorkshire finisher pigs fed phytase; however, only K exhibited enhanced retention. In conclusion, the CA line pigs secrete sufficient phytase from the salivary glands to enable efficient digestion of plant P, Ca, and major electrolyte macrominerals. PMID:23296825

Meidinger, R G; Ajakaiye, A; Fan, M Z; Zhang, J; Phillips, J P; Forsberg, C W

2013-03-01

84

TCreERT2, a transgenic mouse line for temporal control of Cre-mediated recombination in lineages emerging from the primitive streak or tail bud.  

PubMed

The study of axis extension and somitogenesis has been greatly advanced through the use of genetic tools such as the TCre mouse line. In this line, Cre is controlled by a fragment of the T (Brachyury) promoter that is active in progenitor cells that reside within the primitive streak and tail bud and which give rise to lineages emerging from these tissues as the embryonic axis extends. However, because TCre-mediated recombination occurs early in development, gene inactivation can result in an axis truncation that precludes the study of gene function in later or more posterior tissues. To address this limitation, we have generated an inducible TCre transgenic mouse line, called TCreERT2, that provides temporal control, through tamoxifen administration, in all cells emerging from the primitive streak or tail bud throughout development. TCreERT2 activity is mostly silent in the absence of tamoxifen and, in its presence, results in near complete recombination of emerging mesoderm from E7.5 through E13.5. We demonstrate the utility of the TCreERT2 line for determining rate of posterior axis extension and somite formation, thus providing the first in vivo tool for such measurements. To test the usefulness of TCreERT2 for genetic manipulation, we demonstrate that an early deletion of ß-Catenin via TCreERT2 induction phenocopies the TCre-mediated deletion of ß-Catenin defect, whereas a later induction bypasses this early phenotype and produces a similar defect in more caudal tissues. TCreERT2 provides a useful and novel tool for the control of gene expression of emerging embryonic lineages throughout development. PMID:23638095

Anderson, Matthew J; Naiche, L A; Wilson, Catherine P; Elder, Cindy; Swing, Deborah A; Lewandoski, Mark

2013-01-01

85

Development of Oral Epithelial Cell Line ROE2 with Differentiation Potential from Transgenic Rats Harboring Temperature-Sensitive Simian Virus40 Large T-Antigen Gene  

PubMed Central

We have developed an immortalized oral epithelial cell line, ROE2, from fetal transgenic rats harboring temperature-sensitive simian virus 40 large T-antigen gene. The cells grew continuously at either a permissive temperature of 33°C or an intermediate temperature of 37°C. At the nonpermissive temperature of 39°C, on the other hand, growth decreased significantly, and the Sub-G1 phase of the cell cycle increased, indicating that the cells undergo apoptosis at a nonpermissive temperature. Histological and immunocytochemical analyses revealed that ROE2 cells at 37°C had a stratified epithelial-like morphology and expressed cytokeratins Krt4 and Krt13, marker proteins for oral nonkeratinized epithelial cells. Global-scale comprehensive microarray analysis, coupled with bioinformatics tools, demonstrated a significant gene network that was obtained from the upregulated genes. The gene network contained 16 genes, including Cdkn1a, Fos, Krt13, and Prdm1, and was associated mainly with the biological process of skin development in the category of biological functions, organ development. These four genes were validated by quantitative real-time polymerase chain reaction, and the results were nearly consistent with the microarray data. It is therefore anticipated that this cell line will be useful as an in vitro model for studies such as physiological functions, as well as for gene expression in oral epithelial cells. PMID:24521861

Tabuchi, Yoshiaki; Wada, Shigehito; Ikegame, Mika; Kariya, Ayako; Furusawa, Yukihiro; Hoshi, Nobuhiko; Yunoki, Tatsuya; Suzuki, Nobuo; Takasaki, Ichiro; Kondo, Takashi; Suzuki, Yoshihisa

2014-01-01

86

Re-interpreting some common objections to three transgenic applications: GM foods, xenotransplantation and germ line gene modification (GLGM).  

PubMed

Concerns about safety to the individual, the wider community and the potential impact on the environment are typical consequentialist objections to transgenesis that feature prominently in public debates about its ethical acceptability. I consider some of these claims with respect to their motivation, validity and their overall influence on public policy using three well-discussed applications of transgenesis: GM foods, xenotransplantation and germ line gene modification (GLGM). PMID:15672839

Carter, Lucy

2004-12-01

87

Transgenic human ES and iPS reporter cell lines for identification and selection of pluripotent stem cells in vitro.  

PubMed

Optimization of pluripotent stem cell expansion and differentiation is facilitated by biological tools that permit non-invasive and dynamic monitoring of pluripotency, and the ability to select for an undifferentiated input cell population. Here we report on the generation and characterisation of clonal human embryonic stem (HES3, H9) and human induced pluripotent stem cell lines (UQEW01i-epifibC11) that have been stably modified with an artificial EOS(C3+) promoter driving expression of EGFP and puromycin resistance-conferring proteins. We show that EGFP expression faithfully reports on the pluripotency status of the cells in these lines and that antibiotic selection allows for an efficient elimination of differentiated cells from the cultures. We demonstrate that the extinction of the expression of the pluripotency reporter during differentiation closely correlates with the decrease in expression of conventional pluripotency markers, such as OCT4 (POU5F1), TRA-1-60 and SSEA4 when screening across conditions with various levels of pluripotency-maintaining or differentiation-inducing signals. We further illustrate the utility of these lines for real-time monitoring of pluripotency in embryoid bodies and microfluidic bioreactors. PMID:25108530

Ovchinnikov, Dmitry A; Titmarsh, Drew M; Fortuna, Patrick R J; Hidalgo, Alejandro; Alharbi, Samah; Whitworth, Deanne J; Cooper-White, Justin J; Wolvetang, Ernst J

2014-09-01

88

Insect-resistant transgenic Pinus radiata.  

PubMed

Transgenic radiata pine (Pinus radiata D. Don) plants containing a Bacillus thuringiensis (Bt) toxin gene, crylAc, were produced by means of biolistic transformation of embryogenic tissue. Using the selectable marker gene nptII and corresponding geneticin selection, 20 independent transgenic lines from five genotypes were established. Over 200 plants regenerated from ten transgenic lines were successfully transferred to soil. The integration and expression of the introduced genes in transgenic tissue and/or plants were confirmed by PCR, Southern hybridisation and neomycin phosphotransferase II (NPTII) and Bt ELISA assays. Bioassays with larvae of the painted apple moth, Teia anartoides, demonstrated that transgenic plants displayed variable levels of resistance to insect damage, with one transgenic line being highly resistant to feeding damage. PMID:15668791

Grace, Lynette J; Charity, Julia A; Gresham, Belinda; Kay, Nod; Walter, Christian

2005-05-01

89

Comparative Analysis of Osteogenic/Chondrogenic Differentiation Potential in Primary Limb Bud-Derived and C3H10T1/2 Cell Line-Based Mouse Micromass Cultures  

PubMed Central

Murine micromass models have been extensively applied to study chondrogenesis and osteogenesis to elucidate pathways of endochondral bone formation. Here we provide a detailed comparative analysis of the differentiation potential of micromass cultures established from either BMP-2 overexpressing C3H10T1/2 cells or mouse embryonic limb bud-derived chondroprogenitor cells, using micromass cultures from untransfected C3H10T1/2 cells as controls. Although the BMP-2 overexpressing C3H10T1/2 cells failed to form chondrogenic nodules, cells of both models expressed mRNA transcripts for major cartilage-specific marker genes including Sox9, Acan, Col2a1, Snorc, and Hapln1 at similar temporal sequence, while notable lubricin expression was only detected in primary cultures. Furthermore, mRNA transcripts for markers of osteogenic differentiation including Runx2, Osterix, alkaline phosphatase, osteopontin and osteocalcin were detected in both models, along with matrix calcification. Although the adipogenic lineage-specific marker gene FABP4 was also expressed in micromass cultures, Oil Red O-positive cells along with PPAR?2 transcripts were only detected in C3H10T1/2-derived micromass cultures. Apart from lineage-specific marker genes, pluripotency factors (Nanog and Sox2) were also expressed in these models, reflecting on the presence of various mesenchymal lineages as well as undifferentiated cells. This cellular heterogeneity has to be taken into consideration for the interpretation of data obtained by using these models. PMID:23921684

Takacs, Roland; Matta, Csaba; Somogyi, Csilla; Juhasz, Tamas; Zakany, Roza

2013-01-01

90

This work sheet solves Laplace's equation on the upper half plane with boundary conditions T=1 on (-1, 1) and 0 on the rest of the real line except at the points x=1 and -1 where it is undefined.  

E-print Network

on (-1, 1) and 0 on the rest of the real line except at the points x=1 and -1 where it is undefinedFunction Ã? HHue@.9 H1 - #LD &L, ContourLines Ã? False, Contours Ã? 100, ContourLines Ã? False, PlotPoints Ã? 50D, -4, 4H1 - #LD &L, Contours Ã? 100

Stenzel, Matt

91

PVX-Cre-mediated marker gene elimination from transgenic plants.  

PubMed

Cre recombinase gene from bacteriophage P1 was transiently expressed by a Potato Virus X (PVX)-based vector in transgenic lox -target Nicotiana benthamiana plants to remove the selectable marker gene. The target construct consisted of two directly oriented lox sites flanking a bar gene located between a gfp coding region and an upstream CaMV 35S promoter. The Cre-mediated excision of intervening sequence placed the gfp coding region under the transcriptional control of the CaMV 35S promoter. GFP activity was observed in PVX-Cre systemically infected leaves, regenerants from PVX-Cre infected explants and T1 progeny of these regenerants. PVX-Cre was removed efficiently from the regenerants by adding the nucleoside analogue ribavirin to the culture medium. Molecular data proved a correlation between gfp expression and precise site-specific excision of the bar gene in all examined transgenic lines. The frequency of recombination expressed as a percentage of regenerated plants exhibiting marker gene excision varied from 48% to 82%. These results demonstrate that a plant virus vector can be used efficiently to express cre recombinase in vivo providing an alternative method for the production of transgenic plants without marker genes. PMID:15604695

Kopertekh, L; Jüttner, G; Schiemann, J

2004-07-01

92

High levan accumulation in transgenic tobacco plants expressing the Gluconacetobacter diazotrophicus levansucrase gene.  

PubMed

Bacterial levansucrase (EC 2.4.1.10) converts sucrose into non-linear levan consisting of long ?(2,6)-linked fructosyl chains with ?(2,1) branches. Bacterial levan has wide food and non-food applications, but its production in industrial reactors is costly and low yielding. Here, we report the constitutive expression of Gluconacetobacter diazotrophicus levansucrase (LsdA) fused to the vacuolar targeting pre-pro-peptide of onion sucrose:sucrose 1-fructosyltransferase (1-SST) in tobacco, a crop that does not naturally produce fructans. In the transgenic plants, levan with degree of polymerization above 10(4) fructosyl units was detected in leaves, stem, root, and flowers, but not in seeds. High levan accumulation in leaves led to gradual phenotypic alterations that increased with plant age through the flowering stage. In the transgenic lines, the fructan content in mature leaves varied from 10 to 70% of total dry weight. No oligofructans were stored in the plant organs, although the in vitro reaction of transgenic LsdA with sucrose yielded ?(2,1)-linked FOS and levan. Transgenic lines with levan representing up to 30mgg(-1) of fresh leaf weight produced viable seeds and the polymer accumulation remained stable in the tested T1 and T2 progenies. The lsdA-expressing tobacco represents an alternative source of highly polymerized levan. PMID:21540065

Banguela, Alexander; Arrieta, Juan G; Rodríguez, Raisa; Trujillo, Luis E; Menéndez, Carmen; Hernández, Lázaro

2011-06-10

93

Studies of Mice with a Balanced Complement of 36 Chromosomes Derived from F1 Hybrids of T1Wh and T1Ald Translocation Homozygotes  

PubMed Central

F1 hybrids with 38 chromosomes, including single T1Wh and T1Ald translocations, resulted when mice homozygous for the Robertsonian translocations T1Wh and T1Ald were crossed. Meiotic studies of the hybrids showed two trivalents, indicating nonhomology of the T1Wh and T1Ald chromosomes. The hybrids had frequent (25%) unbalanced meiotic metaphase II complements; one trisomic mouse resulted from six F1 crosses. The F1 crosses also produced one mouse with 36 chromosomes homozygous for both T1Wh and T1Ald, as well as mice with balanced polymorphic complements of 37, 38, 39, and 40 chromosomes. By crossing the F2, a homogeneous line with 36 chromosomes was established. The line is phenotypically normal, fertile, and has balanced meiotic metaphase II complements. Analysis of the chromosomes of these mice with quinacrine mustard and the Giemsa-banding technique confirmed that T1Wh and T1Ald consisted of chromosomes 5;19 and 6;15, respectively. Crosses between this line and other existing translocation stocks may produce new strains of mice with even further reduction in chromosome number. Accumulation of Robertsonian translocations, a possible evolutionary mechanism in the wild, can be studied in the laboratory. F1 hybrids from certain crosses are also an important model for human translocation carriers; both have similar meiotic abnormalities and often have aneuploid offspring. Images PMID:4507599

White, Beverly J.; Tjio, Joe-Hin; Water, Lisa C. Van De; Crandall, Clare

1972-01-01

94

NMR profiling of transgenic peas.  

PubMed

A high throughput proton nuclear magnetic resonance spectroscopy method for the metabolite fingerprinting of plants was applied to genetically modified peas (Pisum sativum) to determine whether biochemical changes, so called 'unintended effects', beyond those intended by incorporation of a transgene, were detectable. Multivariate analysis of 1H NMR (nuclear magnetic resonance) spectra obtained from uniformly grown glasshouse plants revealed differences between the transgenic and control group that exceeded the natural variation of the plants. When a larger data set of six related transgenic lines was analysed, including a null segregant in addition to the wild-type control, multivariate analysis showed that the distribution of metabolites in the transgenics was different from that of the null segregant. However, the profile obtained from the wild-type material was diverse in comparison with both the transgenics and the null segregant, suggesting that the primary cause of the observed differences was that the transformation process selects for a subset of individuals able to undergo the transformation and selection procedures, and that their descendants have a restricted variation in metabolite profile, rather than that the presence of the transgene itself generates these differences. PMID:17166140

Charlton, Adrian; Allnutt, Theo; Holmes, Stephen; Chisholm, James; Bean, Samantha; Ellis, Noel; Mullineaux, Phil; Oehlschlager, Sarah

2004-01-01

95

A field-grown transgenic tomato line expressing higher levels of polyamines reveals legume cover crop mulch-specific perturbations in fruit phenotype at the levels of metabolite profiles, gene expression, and agronomic characteristics  

PubMed Central

Genetic modification of crop plants to introduce desirable traits such as nutritional enhancement, disease and pest resistance, and enhanced crop productivity is increasingly seen as a promising technology for sustainable agriculture and boosting food production in the world. Independently, cultural practices that utilize alternative agriculture strategies including organic cultivation subscribe to sustainable agriculture by limiting chemical usage and reduced tillage. How the two together affect fruit metabolism or plant growth in the field or whether they are compatible has not yet been tested. Fruit-specific yeast S-adenosylmethionine decarboxylase (ySAMdc) line 579HO, and a control line 556AZ were grown in leguminous hairy vetch (Vicia villosa Roth) (HV) mulch and conventional black polyethylene (BP) mulch, and their fruit analysed. Significant genotype×mulch-dependent interactions on fruit phenotype were exemplified by differential profiles of 20 fruit metabolites such as amino acids, sugars, and organic acids. Expression patterns of the ySAMdc transgene, and tomato SAMdc, E8, PEPC, and ICDHc genes were compared between the two lines as a function of growth on either BP or HV mulch. HV mulch significantly stimulated the accumulation of asparagine, glutamate, glutamine, choline, and citrate concomitant with a decrease in glucose in the 556AZ fruits during ripening as compared to BP. It enables a metabolic system in tomato somewhat akin to the one in higher polyamine-accumulating transgenic fruit that have higher phytonutrient content. Finally, synergism was found between HV mulch and transgenic tomato in up-regulating N:C indicator genes PEPC and ICDHc in the fruit. PMID:18469323

Neelam, Anil; Cassol, Tatiana; Mehta, Roshni A.; Abdul-Baki, Aref A.; Sobolev, Anatoli P.; Goyal, Ravinder K.; Abbott, Judith; Segre, Anna L.; Handa, Avtar K.; Mattoo, Autar K.

2008-01-01

96

Institute for Systems Biology: T1DBase  

NSDL National Science Digital Library

T1DBase was created jointly by the Institute for Systems Biology, the Juvenile Diabetes Research Foundation International, and the Juvenile Diabetes Research Foundation/Wellcome Trust Diabetes and Inflammation Laboratory to support the work of Type 1 diabetes (T1D) researchers. T1DBase currently "includes annotated genomic sequences for suspected T1D susceptibility regions; microarray data; functional annotation of genes active in beta cells; and 'global' datasets, generally from the literature, that are useful for systems biology studies." Information is available for human, rat, and mouse Type 1 diabetes candidate regions. The site also offers several tools including Gbrowse, Cytoscape, Beta Cell Gene Expression Bank, and Kegg Pathways. T1DBase was created as a community resource, and the website invites researchers to contribute both ideas and data.

97

Icosahedral T1u+T1g Jahn-Teller problem  

NASA Astrophysics Data System (ADS)

The T1u+T1g multimode Jahn-Teller problem in icosahedral symmetry is investigated. It is found that the pseudo-Jahn-Teller interaction between T1u and T1g can give rise to an increase of symmetry through the development of additional troughs in the space of ungerade modes. This result is related to a continuous group invariance of the Hamiltonian. The possible relevance to the Jahn-Teller instability of negatively charged fullerides is discussed.

Ceulemans, A.; Chibotaru, L. F.

1996-02-01

98

The distribution of transgene insertion sites in barley determined by physical and genetic mapping.  

PubMed Central

The exact site of transgene insertion into a plant host genome is one feature of the genetic transformation process that cannot, at present, be controlled and is often poorly understood. The site of transgene insertion may have implications for transgene stability and for potential unintended effects of the transgene on plant metabolism. To increase our understanding of transgene insertion sites in barley, a detailed analysis of transgene integration in independently derived transgenic barley lines was carried out. Fluorescence in situ hybridization (FISH) was used to physically map 23 transgene integration sites from 19 independent barley lines. Genetic mapping further confirmed the location of the transgenes in 11 of these lines. Transgene integration sites were present only on five of the seven barley chromosomes. The pattern of transgene integration appeared to be nonrandom and there was evidence of clustering of independent transgene insertion events within the barley genome. In addition, barley genomic regions flanking the transgene insertion site were isolated for seven independent lines. The data from the transgene flanking regions indicated that transgene insertions were preferentially located in gene-rich areas of the genome. These results are discussed in relation to the structure of the barley genome. PMID:15280249

Salvo-Garrido, Haroldo; Travella, Silvia; Bilham, Lorelei J; Harwood, Wendy A; Snape, John W

2004-01-01

99

[Progress in transgenic fish techniques and application].  

PubMed

Transgenic technique provides a new way for fish breeding. Stable lines of growth hormone gene transfer carps, salmon and tilapia, as well as fluorescence protein gene transfer zebra fish and white cloud mountain minnow have been produced. The fast growth characteristic of GH gene transgenic fish will be of great importance to promote aquaculture production and economic efficiency. This paper summarized the progress in transgenic fish research and ecological assessments. Microinjection is still the most common used method, but often resulted in multi-site and multi-copies integration. Co-injection of transposon or meganuclease will greatly improve the efficiency of gene transfer and integration. "All fish" gene or "auto gene" should be considered to produce transgenic fish in order to eliminate misgiving on food safety and to benefit expression of the transferred gene. Environmental risk is the biggest obstacle for transgenic fish to be commercially applied. Data indicates that transgenic fish have inferior fitness compared with the traditional domestic fish. However, be-cause of the genotype-by-environment effects, it is difficult to extrapolate simple phenotypes to the complex ecological interactions that occur in nature based on the ecological consequences of the transgenic fish determined in the laboratory. It is critical to establish highly naturalized environments for acquiring reliable data that can be used to evaluate the environ-mental risk. Efficacious physical and biological containment strategies remain to be crucial approaches to ensure the safe application of transgenic fish technology. PMID:21586396

Ye, Xing; Tian, Yuan-Yuan; Gao, Feng-Ying

2011-05-01

100

Primary transgenic bovine cells and their rejuvenated cloned equivalents show transgene-specific epigenetic differences.  

PubMed

Cell-mediated transgenesis, based on somatic cell nuclear transfer (SCNT), provides the opportunity to shape the genetic make-up of cattle. Bovine primary fetal fibroblasts, commonly used cells for SCNT, have a limited lifespan, and complex genetic modifications that require sequential transfections can be challenging time and cost-wise. To overcome these limitations, SCNT is frequently used to rejuvenate the cell lines and restore exhausted growth potential. We have designed a construct to be used in a 2-step cassette exchange experiment. Our transgene contains a puromycin resistance marker gene and an enhanced green fluorescence protein (EGFP) expression cassette, both driven by a strong mammalian promoter, and flanked by loxP sites and sequences from the bovine ?-casein locus. Several transgenic cell lines were generated by random insertion into primary bovine cell lines. Two of these original cell lines were rederived by SCNT and new primary cells, with the same genetic makeup as the original donors, were established. While the original cell lines were puromycin-resistant and had a characteristic EGFP expression profile, all rejuvenated cell lines were sensitive to puromycin, and displayed varied EGFP expression, indicative of various degrees of silencing. When the methylation states of individual CpG sites within the transgene were analyzed, a striking increase in transgene-specific methylation was observed in all rederived cell lines. The results indicate that original transgenic donor cells and their rejuvenated derivatives may not be equivalent and differ in the functionality of their transgene sequences. PMID:22532863

Alonso-González, Lucia; Couldrey, Christine; Meinhardt, Marcus W; Cole, Sally A; Wells, David N; Laible, Götz

2012-01-01

101

Transcription-dependent silencing of inducible convergent transgenes in transgenic mice  

E-print Network

hypersensitive sites and inability to recruit RNA polymerase II upon stimulation. This pattern of silencing was reflected by increased methylation and decreased acetylation of histone H3 K9 in the transgene. We found that silenced lines were specifically...

Calero-Nieto, Fernando J; Bert, Andrew G; Cockerill, Peter N

2010-01-19

102

{open_quotes}Horizontal{close_quotes} gene transfer from a transgenic potato line to a bacterial pathogen (Erwinia chrysanthemi) occurs - if at all - at an extremely low frequency  

SciTech Connect

The frequency of possible {open_quotes}horizontal{close_quotes} gene transfer between a plant and a tightly associated bacterial pathogen was studied in a model system consisting of transgenic Solanum tuberosum, containing a {beta}-lactamase gene linked to a pBR322 origin of replication, and Erwinia chrysanthemi. This experimental system offers optimal conditions for the detection of possible horizontal gene transfer events, even when they occur at very low frequency. Horizontal gene transfer was not detected under conditions mimicking a {open_quotes}natural{close_quotes} infection. The gradual, stepwise alteration of artificial, positive control conditions to idealized natural conditions, however, allowed the characterization of factors that affected gene transfer, and revealed a gradual decrease of the gene transfer frequency from 6.3 x 10{sup -2} under optimal control conditions to a calculated 2.0 x 10{sub -17} under idealized natural conditions. These data, in combination with other published studies, argue that horizontal gene transfer is so rare as to be essentially irrelevant to any realistic assessment of the risk involved in release experiments involving transgenic plants. 22 refs., 3 figs., 2 tabs.

Schlueter, K.; Fuetterer, J.; Potrykus, I. [Institute of Plant Sciences, Zuerich (Switzerland)] [Institute of Plant Sciences, Zuerich (Switzerland)

1995-10-01

103

Genetically pyramiding protease-inhibitor genes for dual broad-spectrum resistance against insect and phytopathogens in transgenic tobacco.  

PubMed

Protease inhibitors provide a promising means of engineering plant resistance against attack by insects and pathogens. Sporamin (trypsin inhibitor) from sweet potato and CeCPI (phytocystatin) from taro were stacked in a binary vector, using pMSPOA (a modified sporamin promoter) to drive both genes. Transgenic tobacco lines of T0 and T1 generation with varied inhibitory activity against trypsin and papain showed resistance to both insects and phytopathogens. Larvae of Helicoverpa armigera that ingested tobacco leaves either died or showed delayed growth and development relative to control larvae. Transgenic tobacco-overexpressing the stacked genes also exhibited strong resistance against bacterial soft rot disease caused by Erwinia carotovora and damping-off disease caused by Pythium aphanidermatum. Thus, stacking protease-inhibitor genes, driven by the wound and pathogen responsive pMSPOA promoter, is an effective strategy for engineering crops to resistance against insects and phytopathogens. PMID:20055959

Senthilkumar, Rajendran; Cheng, Chiu-Ping; Yeh, Kai-Wun

2010-01-01

104

Somatic Generation of Hybrid Antibody H Chain Genes in Transgenic Mice via Interchromosomal Gene Conversion  

Microsoft Academic Search

Summary We have constructed lines of mice with transgenes containing an antibody heavy (H) chain variable region (VHDJ.) gene and various amounts of natural immunoglobulin (Ig) and plasmid flanking DNA. In these lines, recombination of the transgene and the endogenous Igh locus takes place in B cells, leading to the expression of functional H chains partially encoded by the transgenic

Angela M. Giusti; Tim Manser

1994-01-01

105

Generation of a fluorescent transgenic zebrafish for detection of environmental estrogens  

Microsoft Academic Search

To establish a novel in vivo test system for rapid detection of environmental estrogens, an ere-zvtg1: gfp transgenic zebrafish line has been generated. In this transgenic line, under control conditions, GFP was exclusively expressed in the liver of mature adult female fish. Male and larval transgenic fish did not express GFP but could be induced to express GFP in the

Haozhu Chen; Jingying Hu; Jian Yang; Yuexiang Wang; Hui Xu; Qiu Jiang; Yuebo Gong; Yinliang Gu; Houyan Song

2010-01-01

106

Recombineering strategies for developing next generation BAC transgenic tools for optogenetics and beyond  

E-print Network

The development and application of diverse BAC transgenic rodent lines has enabled rapid progress for precise molecular targeting of genetically-defined cell types in the mammalian central nervous system. These transgenic ...

Feng, Guoping

107

Overexpression of Plant Uncoupling Mitochondrial Protein in Transgenic Tobacco Increases Tolerance to Oxidative Stress  

Microsoft Academic Search

An Arabidopsis thaliana cDNA clone encoding a plant uncoupling mitochondrial protein (AtPUMP1) was overexpressed in transgenic tobacco plants. Analysis of the AtPUMP1 mRNA content in the transgenic lines, determined by Northernblot, revealed variable levels of transgene expression. Antibody probing ofWestern blots of mitochondrial proteins from three independent transgenic lines showed significant accumulation of AtPUMP1 in this organelle. Overproduction of AtPUMP1

Marcos Brandalise; Ivan G. Maia; Jiri Borecký; Aníbal E. Vercesi; Paulo Arruda

2003-01-01

108

Generation of transgenic hydra by embryo microinjection.  

PubMed

As a member of the phylum Cnidaria, the sister group to all bilaterians, Hydra can shed light on fundamental biological processes shared among multicellular animals. Hydra is used as a model for the study of regeneration, pattern formation, and stem cells. However, research efforts have been hampered by lack of a reliable method for gene perturbations to study molecular function. The development of transgenic methods has revitalized the study of Hydra biology(1). Transgenic Hydra allow for the tracking of live cells, sorting to yield pure cell populations for biochemical analysis, manipulation of gene function by knockdown and over-expression, and analysis of promoter function. Plasmid DNA injected into early stage embryos randomly integrates into the genome early in development. This results in hatchlings that express transgenes in patches of tissue in one or more of the three lineages (ectodermal epithelial, endodermal epithelial, or interstitial). The success rate of obtaining a hatchling with transgenic tissue is between 10% and 20%. Asexual propagation of the transgenic hatchling is used to establish a uniformly transgenic line in a particular lineage. Generating transgenic Hydra is surprisingly simple and robust, and here we describe a protocol that can be easily implemented at low cost. PMID:25285460

Juliano, Celina E; Lin, Haifan; Steele, Robert E

2014-01-01

109

[Advances on transgene containment technologies].  

PubMed

The biosecurity of transgenic organism has been widely concerned and extremely restricted its application. Recently, many technological strategies have been developed to ensure its biosecurity. Thus, transgene containment technologies have become one of the hotspots in current transgenic research. In this paper, several transgene containment technologies, such as marker-free transgenic technology, safety marker transgenic technology, chloroplast transgenic technologies, terminator technology, male sterility technology, and 'GM-gene-deletor'technology were reviewed and evaluated. 'GM-gene-deletor' technology, as one of these technologies, demonstrated a prosperous future for safe application of transgenic organisms. Finally, the strategies for developing new transgene containment technologies have been suggested. PMID:21586390

Zhang, Qian; Zhang, Jin-Feng; Fu, Wen-Feng; Zhang, Hong-Jing; Yuan, Wen-Jun

2011-05-01

110

Advances in transgenic rat production  

Microsoft Academic Search

Predictable and reproducible production of transgenic rats from a standardized input of egg donors and egg recipients is essential for routine rat model production. In the course of establishing a transgenic rat service, transgenic founders were produced from three transgenes in outbred Sprague-Dawley (SD) rats and four transgenes in inbred Fischer 344 (F344) rats. Key parameters that affect transgenesis efficiency

Wanda E. Filipiak; Thomas L. Saunders

2006-01-01

111

Differentiation-specific regulation of transgene expression in a diploid epithelial cell line derived from the normal F344 rat liver.  

PubMed

To establish the differentiation potential of progenitor cells, non-parenchymal epithelial cells from the F344 rat liver (FNRL cells) were studied. These cells reacted with the OV-6 antibody marker of oval cells, but were negative for hepatocyte markers (albumin, transferrin, glycogen, glucose-6-phosphatase, H4 antigen), biliary markers (gamma glutamyl transpeptidase, cytokeratin-19), and alpha-fetoprotein, although exposure to sodium butyrate induced nascent albumin and alpha-fetoprotein mRNA transcription. When stably transduced, FNRL cells expressed a retroviral promotor-driven lacZ reporter in vitro, similar to transgene expression in hepatocyte-derived HepG2 cells. However, lacZ expression in FNRL cells was rapidly extinguished in intact animals, whereas the reporter remained active in HepG2 cells. Transplanted FNRL cells showed copious glucose-6-phosphatase expression; however, the cell differentiation programme remained incomplete, despite two-thirds partial hepatectomy, D-galactosamine treatment or bile duct ligation. Interestingly, lacZ expression resumed in cultures of FNRL cells explanted from recipients. Moreover, lacZ expression was down-regulated by gamma-interferon in FNRL cells, without affecting lacZ activity in HepG2 cells. The data indicate that although subpopulations of oval cells may not fully differentiate into mature hepatocytes, these cells might serve critical functions, such as glucose utilization, and help survival after liver injury. Also, introduced genes may be regulated in progenitor cells at multiple levels, including by interactions between regulatory sequences, differentiation-specific cellular factors, and extracellular signals; in vivo studies are thus especially important for analysing gene regulation in progenitor cells. PMID:10398093

Ott, M; Rajvanshi, P; Sokhi, R P; Alpini, G; Aragona, E; Dabeva, M; Shafritz, D A; Gupta, S

1999-02-01

112

Selection of transgenic Xenopus laevis using antibiotic resistance  

Microsoft Academic Search

We previously established lines of transgenic Xenopus laevis expressing green fluorescent protein (GFP) or GFP fusion proteins in the rod photoreceptors of their retinas under control of the X. laevis opsin promoter, which permits easy identification of transgenic animals by fluorescence microscopy. However, GFP tags can alter the properties of fusion partners, and in many circumstances a second selectable marker

Orson L. Moritz; Kathleen E. Biddle; Beatrice M. Tam

2002-01-01

113

SirT1 gain-of-function increases energy efficiency and prevents diabetes in mice  

PubMed Central

Summary In yeast, worms and flies, an extra copy of the gene encoding the Sirtuin Sir2 increases metabolic efficiency, as does administration of polyphenols like resveratrol, thought to act through Sirtuins. But evidence that Sirtuin gain-of-function results in increased metabolic efficiency in mammals is limited. We generated transgenic mice with moderate overexpression of SirT1, designed to mimic the Sirtuin gain-of-function that improves metabolism in C.elegans. These mice exhibit normal insulin sensitivity, but decreased food intake and locomotor activity, resulting in decreased energy expenditure. However, in various models of insulin resistance and diabetes, SirT1 transgenics display improved glucose tolerance due to decreased hepatic glucose production and increased adiponectin levels, without changes in body weight or composition. We conclude that SirT1 gain-of-function primes the organism for metabolic adaptation to insulin resistance, increasing hepatic insulin sensitivity and decreasing whole-body energy requirements. These findings have important implications for Sirtuin-based therapies in humans. PMID:18840364

Banks, Alexander S.; Kon, Ning; Knight, Colette; Matsumoto, Michihiro; Gutierrez-Juarez, Roger; Rossetti, Luciano; Gu, Wei; Accili, Domenico

2011-01-01

114

Generation of Transgenic Mice  

PubMed Central

This unit describes detailed step-by-step protocols, reagents, and equipment required for successful generation of transgenic mice using pronuclear injection. The experimental methods and practical tips given here will help guide beginners in understanding what is required and what to avoid in these standard protocols for efficiently generating transgenic mice. PMID:19283729

Cho, Andrew; Haruyama, Naoto; Kulkarni, Ashok B.

2009-01-01

115

Transgenic cotton over-producing spinach sucrose phosphate synthase showed enhanced leaf sucrose synthesis and improved  

E-print Network

Environmental stress Á Sucrose, starch, and cellulose metabolism Á Transgenic cotton C. H. Haigler (&) Á B-type and transgenic null controls. Leaves of transgenic SPS over-expressing lines showed higher sucrose:starch ra- tio and partitioning of 14 C to sucrose in preference to starch. In two growth chamber experiments with cool nights

Strauss, Richard E.

116

Competitive Performance of Transgenic Wheat Resistant to Powdery Mildew  

PubMed Central

Genetically modified (GM) plants offer an ideal model system to study the influence of single genes that confer constitutive resistance to pathogens on the ecological behaviour of plants. We used phytometers to study competitive interactions between GM lines of spring wheat Triticum aestivum carrying such genes and control lines. We hypothesized that competitive performance of GM lines would be reduced due to enhanced transgene expression under pathogen levels typically encountered in the field. The transgenes pm3b from wheat (resistance against powdery mildew Blumeria graminis) or chitinase and glucanase genes from barley (resistance against fungi in general) were introduced with the ubiquitin promoter from maize (pm3b and chitinase genes) or the actin promoter from rice (glucanase gene). Phytometers of 15 transgenic and non-transgenic wheat lines were transplanted as seedlings into plots sown with the same 15 lines as competitive environments and subject to two soil nutrient levels. Pm3b lines had reduced mildew incidence compared with control lines. Chitinase and chitinase/glucanase lines showed the same high resistance to mildew as their control in low-nutrient treatment and slightly lower mildew rates than the control in high-nutrient environment. Pm3b lines were weaker competitors than control lines. This resulted in reduced yield and seed number. The Pm3b line with the highest transgene expression had 53.2% lower yield than the control whereas the Pm3b line which segregated in resistance and had higher mildew rates showed only minor costs under competition. The line expressing both chitinase and glucanase genes also showed reduced yield and seed number under competition compared with its control. Our results suggest that single transgenes conferring constitutive resistance to pathogens can have ecological costs and can weaken plant competitiveness even in the presence of the pathogen. The magnitude of these costs appears related to the degree of expression of the transgenes. PMID:22132219

Kalinina, Olena; Zeller, Simon L.; Schmid, Bernhard

2011-01-01

117

The impurity transport model in IR-T1 Tokamak  

SciTech Connect

Low-z impurities in a Tokamak discharge affect not only the plasma composition and hence the resistivity but also the local power balance and the maximum plasma density attainable. The impurity accumulation in Tokamak is determined by the impurity influx from the edge, and by the impurity transport in plasma. Spectroscopic measurements of line emission are commonly used to evaluate the accumulation, influx rate and power radiated by light impurities. The measurement thus have been analyzed by using a one-dimensional transport model. The transport for low-z impurities in IR-T1 Tokamak has been studied theoretically and in conjunction with several experiments. As a result the authors have determined some ionization stage profiles of main components of impurities with a single channel visible spectrometer. A one-dimensional impurity transport code has been set up, and some characteristics of the impurity transport in IR-T1 Tokamak have been analyzed. The solar corona model was used to relate the stage densities and line emissivities. The experimental results were also simulated approximately and they found that the majority of the oxygen and carbon ions are He-like ones. Also the stage profile peaks occur at radial positions where the electron temperatures are approximately equal to their ionization potentials.

Ghoranneviss, M.; Salami, M.R.; Masnavi, M.; Zamani, M. [I.A.U., Tehran (Iran, Islamic Republic of). Plasma Physics Research Center

1996-12-31

118

Evaluating the fitness of human lysozyme transgenic dairy goats: growth and reproductive traits.  

PubMed

While there are many reports in the literature describing the attributes of specific applications of transgenic animals for agriculture, there are relatively few studies focusing on the fitness of the transgenic animals themselves. This work was designed to gather information on genetically modified food animals to determine if the presence of a transgene can impact general animal production traits. More specifically, we used a line of transgenic dairy goats expressing human lysozyme in their mammary gland to evaluate the reproductive fitness and growth and development of these animals compared to their non-transgenic counterparts and the impact of consuming a transgenic food product, lysozyme-containing milk. In males, none of the parameters of semen quality, including semen volume and concentration, total sperm per ejaculate, sperm morphology, viability and motility, were significantly different between transgenic bucks and non-transgenic full-sib controls. Likewise, transgenic females of this line did not significantly differ in the reproductive traits of gestation length and litter size compared to their non-transgenic counterparts. To evaluate growth, transgenic and non-transgenic kid goats received colostrum and milk from either transgenic or non-transgenic does from birth until weaning. Neither the presence of the transgene nor the consumption of milk from transgenic animals significantly affected birth weight, weaning weight, overall gain and post-wean gain. These results indicate that the analyzed reproductive and growth traits were not regularly or substantially impacted by the presence or expression of the transgene. The evaluation of these general parameters is an important aspect of defining the safety of applying transgenic technology to animal agriculture. PMID:20135222

Jackson, Kathryn A; Berg, Jolene M; Murray, James D; Maga, Elizabeth A

2010-12-01

119

T1D in College (Type 1 Diabetes)  

MedlinePLUS

... Life with T1D / T1D in College T1D in College College for young adults with T1D means more ... college students. Dealing with a new diagnosis in college A diabetes diagnosis is shocking at any point ...

120

The cyclic AMP response element directs tyrosine hydroxylase expression in catecholaminergic central and peripheral nervous system cell lines from transgenic mice.  

PubMed

Enhancer elements regulating the neuronal gene, tyrosine hydroxylase (TH), were identified in TH-expressing peripheral nervous system PATH and central nervous system CATH cell lines. Mutational analysis in which rat TH 5'-flanking sequences directed chloramphenicol acetyltransferase (CAT) reporter gene expression demonstrated that mutating the cyclic AMP response element (CRE) at -45 base pair reduced expression by 80-90%. A CRE linked to an enhancerless TH promoter fully supported expression. Cotransfection of a dominant-negative CREB protein reduced expression 50-60%, suggesting that the CRE is bound by CREB or a CREB dimerization partner. Although mutating the AP1/dyad (AD) element at -205 base pair only modestly reduced CAT levels, AD minimal enhancer constructs gave 45-80% of wild type expression when positioned at -91 or -95. However, in its native context at -205, the AD could not support expression. In contrast, a CRE, moved from its normal position at -45 to -206, gave full activity. These results indicate that the CRE is critical for TH transcription in central nervous system CATH and peripheral nervous system PATH cells, whereas the AD is less important and its enhancer activity is context-and/or position-dependent. These results represent the first attempts to map regulatory elements directing TH expression in central nervous system cell lines. PMID:7665571

Lazaroff, M; Patankar, S; Yoon, S O; Chikaraishi, D M

1995-09-15

121

Lines  

ERIC Educational Resources Information Center

National Geography Standards for the middle school years generally stress the teaching of latitude and longitude. There are many creative ways to explain the great grid that encircles our planet, but the author has found that students in his college-level geography courses especially enjoy human-interest stories associated with lines of latitude…

Mires, Peter B.

2006-01-01

122

Up-regulation of an N-terminal truncated 3-hydroxy-3-methylglutaryl CoA reductase enhances production of essential oils and sterols in transgenic Lavandula latifolia.  

PubMed

Spike lavender (Lavandula latifolia) essential oil is widely used in the perfume, cosmetic, flavouring and pharmaceutical industries. Thus, modifications of yield and composition of this essential oil by genetic engineering should have important scientific and commercial applications. We generated transgenic spike lavender plants expressing the Arabidopsis thaliana HMG1 cDNA, encoding the catalytic domain of 3-hydroxy-3-methylglutaryl CoA reductase (HMGR1S), a key enzyme of the mevalonic acid (MVA) pathway. Transgenic T0 plants accumulated significantly more essential oil constituents as compared to controls (up to 2.1- and 1.8-fold in leaves and flowers, respectively). Enhanced expression of HMGR1S also increased the amount of the end-product sterols, beta-sitosterol and stigmasterol (average differences of 1.8- and 1.9-fold, respectively), but did not affect the accumulation of carotenoids or chlorophylls. We also analysed T1 plants derived from self-pollinated seeds of T0 lines that flowered after growing for 2 years in the greenhouse. The increased levels of essential oil and sterols observed in the transgenic T0 plants were maintained in the progeny that inherited the HMG1 transgene. Our results demonstrate that genetic manipulation of the MVA pathway increases essential oil yield in spike lavender, suggesting a contribution for this cytosolic pathway to monoterpene and sesquiterpene biosynthesis in leaves and flowers of the species. PMID:17714440

Muñoz-Bertomeu, Jesús; Sales, Ester; Ros, Roc; Arrillaga, Isabel; Segura, Juan

2007-11-01

123

Transgenic tobacco expressing Pinellia ternata agglutinin confers enhanced resistance to aphids.  

PubMed

Tobacco leaf discs were transformed with a plasmid, pBIPTA, containing the selectable marker neomycin phosphotransferase gene (nptII) and Pinellia ternata agglutinin gene (pta) via Agrobacterium tumefaciens-mediated transformation. Thirty-two independent transgenic tobacco plants were regenerated. PCR and Southern blot analyses confirmed that the pta gene had integrated into the plant genome and northern blot analysis revealed transgene expression at various levels in transgenic plants. Genetic analysis confirmed Mendelian segregation of the transgene in T1 progeny. Insect bioassays showed that transgenic plants expressing PTA inhibited significantly the growth of peach potato aphid (Myzus persicae Sulzer). This is the first report that transgenic plants expressing pta confer enhanced resistance to aphids. Our study indicates that the pta gene can be used as a supplement to the snowdrop (Galanthus nivalis) lectin gene (gna) in the control of aphids, a sap-sucking insect pest causing significant yield losses of crops. PMID:14713200

Yao, Jianhong; Pang, Yongzhen; Qi, Huaxiong; Wan, Bingliang; Zhao, Xiuyun; Kong, Weiwen; Sun, Xiaofen; Tang, Kexuan

2003-12-01

124

Safety Evaluation of Transgenic Tilapia with Accelerated Growth  

Microsoft Academic Search

.   Recent advances in modern marine biotechnology have permitted the generation of new strains of economically important fish\\u000a species through the transfer of growth hormone genes. These transgenic fish strains show improved growth performance and therefore\\u000a constitute a better alternative for aquaculture programs. Recently, we have obtained a transgenic tilapia line with accelerated\\u000a growth. However, before introducing this line into

Isabel Guillén; Jorge Berlanga; Carmen M. Valenzuela; Antonio Morales; José Toledo; Mario P. Estrada; Pedro Puentes; Orlando Hayes; José de la Fuente

1999-01-01

125

Spatial learning in transgenic mice expressing human presenilin 1 (PS1) transgenes  

Microsoft Academic Search

Dominant mutations in the Presenilin 1 gene are linked to an aggressive, early-onset form of familial Alzheimer’s Disease (FAD). Spatial memory of transgenic (Tg) mice expressing either mutant (lines Tg(M146L)1, Tg(M146L)76, Tg(L286V)198) or wild type (line Tg(PS1wt)195) human PS1 transgenes was investigated in the Morris water maze (WM) test at 6 and 9 months of age. The results showed that

C Janus; S D’Amelio; O Amitay; M. A Chishti; R Strome; P Fraser; G. A Carlson; J. C Roder; D Westaway

2000-01-01

126

Copy Number Related Transgene Expression and Mosaic Somatic Expression in Hemizygous and Homozygous Transgenic Tilapia (Oreochromis Niloticus)  

Microsoft Academic Search

Three lines of transgenic tilapia (Oreochromisniloticus) fish were generated with a constructcontaining a lacZ reporter gene spliced to a 4.7?kb 5' regulatory region of a carp beta actin gene. All these three lines contain different copy numbers oftransgenes and the levels of lacZ expressionwere found to be related to transgene copy number.Mosaic patterns of somatic lacZ expression wereobserved in these

M. Azizur Rahman; Gyu-Lin Hwang; Shaharudin Abdul Razak; Frédéric Sohm; Norman Maclean

2000-01-01

127

MOLLI and AIR T1 mapping pulse sequences yield different myocardial T1 and ECV measurements.  

PubMed

Both post-contrast myocardial T1 and extracellular volume (ECV) have been reported to be associated with diffuse interstitial fibrosis. Recently, the cardiovascular magnetic resonance (CMR) field is recognizing that post-contrast myocardial T1 is sensitive to several confounders and migrating towards ECV as a measure of collagen volume fraction. Several recent studies using widely available Modified Look-Locker Inversion-recovery (MOLLI) have reported ECV cutoff values to distinguish between normal and diseased myocardium. It is unclear if these cutoff values are translatable to different T1 mapping pulse sequences such as arrhythmia-insensitive-rapid (AIR) cardiac T1 mapping, which was recently developed to rapidly image patients with cardiac rhythm disorders. We sought to evaluate, in well-controlled canine and pig experiments, the relative accuracy and precision, as well as intra- and inter-observer variability in data analysis, of ECV measured with AIR as compared with MOLLI. In 16 dogs, as expected, the mean T1 was significantly different (p?T1 calculations were higher for MOLLI than AIR, but intra- and inter-observer agreements in ECV calculations were similar between MOLLI and AIR. In six pigs, the coefficient of repeatability (CR), as defined by the Bland-Altman analysis, in T1 calculation was considerably lower for MOLLI (32.5?ms) than AIR (82.3?ms), and the CR in ECV calculation was also lower for MOLLI (1.8%) than AIR (4.5%). In conclusion, this study shows that MOLLI and AIR yield significantly different T1 and ECV values in large animals and that MOLLI yields higher precision than AIR. Findings from this study suggest that CMR researchers must consider the specific pulse sequence when translating published ECV cutoff values into their own studies. Copyright © 2014 John Wiley & Sons, Ltd. PMID:25323070

Hong, KyungPyo; Kim, Daniel

2014-11-01

128

Transgenic animal bioreactors  

Microsoft Academic Search

The production of recombinant proteins is one of the major successes of biotechnology. Animal cells are required to synthesize\\u000a proteins with the appropriate post-translational modifications. Transgenic animals are being used for this purpose. Milk,\\u000a egg white, blood, urine, seminal plasma and silk worm cocoon from transgenic animals are candidates to be the source of recombinant\\u000a proteins at an industrial scale.

Louis Marie Houdebine

2000-01-01

129

Imaging Transgene Activity  

PubMed Central

The successful translation of gene therapy for clinical application will require the assessment of transgene activity as a measure of the biological function of a therapeutic transgene. While current imaging permits the non-invasive detection of transgene expression, the critical need for quantitative imaging of the action of the expressed transgene has not been met. Magnetic resonance spectroscopic imaging (MRSI) was applied to quantitatively delineate both the concentration and activity of a cytosine deaminase-uracil phosphoribosyltransferase (CD-UPRT) fusion enzyme expressed from a transgene. MRSI enabled the generation of anatomically accurate maps of the intratumoral heterogeneity in fusion enzyme activity. We observed an excellent association between the CD-UPRT concentration and activity and the percentage of CD-UPRT+ cells. Moreover, the regional levels of UPRT activity, as measured by imaging, correlated well with the biological affect of this enzyme. This study presents a translational imaging strategy for precise, in vivo measurements of transgene activity with potential applications in both pre-clinical and clinical settings. PMID:18413756

Gade, Terence P.F.; Koutcher, Jason A.; Spees, William M.; Beattie, Bradley J.; Ponomarev, Vladimir; Doubrovin, Michael; Buchanan, Ian M.; Beresten, Tatiana; Zakian, Kristen L.; Le, H. Carl; Tong, William P.; Mayer-Kuckuk, Philipp; Blasberg, Ronald G.; Gelovani, Juri G.

2009-01-01

130

Transgenic Gladiolus plants transformed with the bean yellow mosaic virus coat-protein gene in either sense or antisense orientation.  

PubMed

Transgenic Gladiolus plants transformed with the bean yellow mosaic virus (BYMV) coat-protein (CP) gene in either sense or antisense (AS) orientation were developed using biolistics. Four of the plants were confirmed to carry the CP gene in the sense orientation of the gene and seven plants in the AS orientation. Two of the CP plant lines and all of the AS lines showed DNA rearrangements of the transgene in addition to an intact copy of the transgene. The copy number ranged from one to nine. Of the 11 lines, eight had only one to four copies of the transgene. Transcription of the transgene occurred for three of the CP lines and five of the AS lines as determined by Northern hybridization. All 11 plant lines were challenged with BYMV using controlled aphid transmission. One month following aphid transmission, the transgenic plants were examined by immunoelectron microscopy for presence of the virus. Several transgenic plant lines containing either antiviral transgene showed a lower incidence of infection (percentage of plants infected as detected by immunoelectron microscopy) than the non-transformed plants. Most of the CP- and AS-transgenic plants that did not contain BYMV 1 month after challenge were found to contain BYMV the next season. It appeared that BYMV infection was delayed in the CP- and AS-transgenic lines but that the transgenes did not prevent eventual infection of BYMV. This is the first report of developing a floral bulb crop with antiviral genes to BYMV. PMID:15480682

Kamo, Kathryn; Gera, Abed; Cohen, Jacob; Hammond, John; Blowers, Alan; Smith, Franzine; Van Eck, Joyce

2005-02-01

131

Expression of spearmint limonene synthase in transgenic spike lavender results in an altered monoterpene composition in developing leaves.  

PubMed

We generated transgenic spike lavender (Lavandula latifolia) plants constitutively expressing the limonene synthase (LS) gene from spearmint (Mentha spicata), encoding the LS enzyme that catalyzes the synthesis of limonene from geranyl diphosphate. Overexpression of the LS transgene did not consistently affect monoterpene profile in pooled leaves or flowers from transgenic T(0) plants. Analyses from cohorts of leaves sampled at different developmental stages showed that essential oil accumulation in transgenic and control plants was higher in developing than in mature leaves. Furthermore, developing leaves of transgenic plants contained increased limonene contents (more than 450% increase compared to controls) that correlated with the highest transcript accumulation of the LS gene. The levels of other monoterpene pathway components were also significantly altered. T(0) transgenic plants were grown for 2 years, self-pollinated, and the T(1) seeds obtained. The increased limonene phenotype was maintained in the progenies that inherited the LS transgene. PMID:18514005

Muñoz-Bertomeu, Jesús; Ros, Roc; Arrillaga, Isabel; Segura, Juan

2008-01-01

132

Split-Cre Complementation Restores Combination Activity on Transgene Excision in Hair Roots of Transgenic Tobacco  

PubMed Central

The Cre/loxP system is increasingly exploited for genetic manipulation of DNA in vitro and in vivo. It was previously reported that inactive ‘‘split-Cre’’ fragments could restore Cre activity in transgenic mice when overlapping co-expression was controlled by two different promoters. In this study, we analyzed recombination activities of split-Cre proteins, and found that no recombinase activity was detected in the in vitro recombination reaction in which only the N-terminal domain (NCre) of split-Cre protein was expressed, whereas recombination activity was obtained when the C-terminal (CCre) or both NCre and CCre fragments were supplied. We have also determined the recombination efficiency of split-Cre proteins which were co-expressed in hair roots of transgenic tobacco. No Cre recombination event was observed in hair roots of transgenic tobacco when the NCre or CCre genes were expressed alone. In contrast, an efficient recombination event was found in transgenic hairy roots co-expressing both inactive split-Cre genes. Moreover, the restored recombination efficiency of split-Cre proteins fused with the nuclear localization sequence (NLS) was higher than that of intact Cre in transgenic lines. Thus, DNA recombination mediated by split-Cre proteins provides an alternative method for spatial and temporal regulation of gene expression in transgenic plants. PMID:25329460

Wen, Mengling; Gao, Yuan; Wang, Lijun; Ran, Lingyu; Li, Jiahui; Luo, Keming

2014-01-01

133

Split-cre complementation restores combination activity on transgene excision in hair roots of transgenic tobacco.  

PubMed

The Cre/loxP system is increasingly exploited for genetic manipulation of DNA in vitro and in vivo. It was previously reported that inactive ''split-Cre'' fragments could restore Cre activity in transgenic mice when overlapping co-expression was controlled by two different promoters. In this study, we analyzed recombination activities of split-Cre proteins, and found that no recombinase activity was detected in the in vitro recombination reaction in which only the N-terminal domain (NCre) of split-Cre protein was expressed, whereas recombination activity was obtained when the C-terminal (CCre) or both NCre and CCre fragments were supplied. We have also determined the recombination efficiency of split-Cre proteins which were co-expressed in hair roots of transgenic tobacco. No Cre recombination event was observed in hair roots of transgenic tobacco when the NCre or CCre genes were expressed alone. In contrast, an efficient recombination event was found in transgenic hairy roots co-expressing both inactive split-Cre genes. Moreover, the restored recombination efficiency of split-Cre proteins fused with the nuclear localization sequence (NLS) was higher than that of intact Cre in transgenic lines. Thus, DNA recombination mediated by split-Cre proteins provides an alternative method for spatial and temporal regulation of gene expression in transgenic plants. PMID:25329460

Wen, Mengling; Gao, Yuan; Wang, Lijun; Ran, Lingyu; Li, Jiahui; Luo, Keming

2014-01-01

134

Field performance of chitinase transgenic silver birch ( Betula pendula Roth): growth and adaptive traits  

Microsoft Academic Search

Fifteen transgenic birch lines carrying a chitinase IV gene from sugar beet and non-transgenic control plants were grown in\\u000a a field trial, and traits connected to growth, quality and adaptation were monitored. Significant variation among the transgenic\\u000a lines was observed in the growth parameters as well as parameters linked to stress status and leaf phenology of the trees.\\u000a It was

Hanna-Leena Pasonen; Liisa Vihervuori; Sanna-Kaisa Seppänen; Päivi Lyytikäinen-Saarenmaa; Tiina Ylioja; Kim von Weissenberg; Ari Pappinen

2008-01-01

135

Age-Dependent Phenotypic Characteristics of a Triple Transgenic Mouse Model of Alzheimer Disease  

Microsoft Academic Search

The triple-transgenic mouse line (3×Tg-AD) harboring PS1M146V, APPSwe, and taup301L transgenes represents the only transgenic model for Alzheimer's disease (AD) to date capturing both ?-amyloid and tau neuropathology. The present study provides an extensive behavioral characterization of the 3×Tg-AD mouse line, evaluating the emergence of noncognitive and cognitive AD-like symptoms at two ages corresponding to the early (6–7 months) and

Susanna Pietropaolo; Joram Feldon; Benjamin K. Yee

2008-01-01

136

Sampling Submicron T1 Bacteriophage Aerosols  

PubMed Central

Liquid impingers, filter papers, and fritted bubblers were partial viable collectors of radioactive submicron T1 bacteriophage aerosols at 30, 55, and 85% relative humidity. Sampler differences for viable collection were due to incomplete physical collection (slippage) and killing of phage by the samplers. Dynamic aerosols of a mass median diameter of 0.2 ? were produced with a Dautrebande generator from concentrated aqueous purified phage suspensions containing extracellular soluble radioactive phosphate as a physical tracer. There was considerable destruction of phage by the Dautrebande generator; phage titers of the Dautrebande suspension decreased exponentially, but there was a progressive (linear) increase in tracer titers. Liquid impingers recovered the most viable phage but allowed considerable (30 to 48%) slippage, which varies inversely with the aerosol relative humidity. Filter papers were virtually complete physical collectors of submicron particles but were the most destructive. Fritted bubbler slippage was more than 80%. With all samplers, phage kill was highest at 85% relative humidity and lowest at 55% relative humidity. An electrostatic precipitator was used to collect aerosol samples for particle sizing with an electron microscope. The particle size was slightly larger at 85% relative humidity than at 30 or 55% relative humidity. Images Fig. 1 Fig. 4 PMID:5866038

Harstad, J. Bruce

1965-01-01

137

Dealing with a New T1D Diagnosis in College  

MedlinePLUS

... New T1D Diagnosis in College Dealing with a New T1D Diagnosis in College A diabetes diagnosis is shocking at any point in life, but a new diagnosis can be especially difficult in college. Most ...

138

[Expression of two plant agglutinin genes in transgenic tobacco plants].  

PubMed

A plant expression vector pBACG containing the DNA sequence coding for Amaranthus caudatus agglutinin (ACA) and a modified Glanthus nivalis agglutinin (GNA) gene was constructed. Leaf explants of Nicotiana tobacum cv. SRI were transformed with A. tumefaciens LBA4404 harbouring the above expression vector. Results from PCR and Southern blotting analysis showed that both the ACA and GNA gene were inserted into the genome of transformed tobacco plants. Western blottingting analysis of soluble protein isolated from transgenic plants showed that ACA and GNA were synthesized. The results from insect bioassay with peach aphids ( Myzus persicae) revealed that the transgenic plants of pBACG had acquired high resistance against peach aphids. The average aphid-inhibition rate reached up to 83.9% and 85.3% for transgenic plants (T0) and their selfed progenies (T1) respectively,indicating that the functions of these two genes were inheritable. PMID:16078746

Liu, Zhao-Hua; Zhang, Zhen-Shan; Guo, Hong-Nian; Jia, Yan-Tao; Zheng, Guang-Yu; Tian, Ying-Chuan

2005-07-01

139

A multi-year assessment of the environmental impact of transgenic Eucalyptus trees harboring a bacterial choline oxidase gene on biomass, precinct vegetation and the microbial community.  

PubMed

A 4-year field trial for the salt tolerant Eucalyptus globulus Labill. harboring the choline oxidase (codA) gene derived from the halobacterium Arthrobacter globiformis was conducted to assess the impact of transgenic versus non-transgenic trees on biomass production, the adjacent soil microbial communities and vegetation by monitoring growth parameters, seasonal changes in soil microbes and the allelopathic activity of leaves. Three independently-derived lines of transgenic E. globulus were compared with three independent non-transgenic lines including two elite clones. No significant differences in biomass production were detected between transgenic lines and non-transgenic controls derived from same seed bulk, while differences were seen compared to two elite clones. Significant differences in the number of soil microbes present were also detected at different sampling times but not between transgenic and non-transgenic lines. The allelopathic activity of leaves from both transgenic and non-transgenic lines also varied significantly with sampling time, but the allelopathic activity of leaves from transgenic lines did not differ significantly from those from non-transgenic lines. These results indicate that, for the observed variables, the impact on the environment of codA-transgenic E. globulus did not differ significantly from that of the non-transformed controls on this field trial. PMID:24927812

Oguchi, Taichi; Kashimura, Yuko; Mimura, Makiko; Yu, Xiang; Matsunaga, Etsuko; Nanto, Kazuya; Shimada, Teruhisa; Kikuchi, Akira; Watanabe, Kazuo N

2014-10-01

140

Global Regulation of Transgenic Crops  

Microsoft Academic Search

Globally, transgenic maize comprised about 25% of the 102 million hectares of transgenic cropland planted in 2006 by more\\u000a than 10 million farmers in 21 countries (James 2007). These transgenic maize plants contain inserted gene(s) expressing a\\u000a variety of Cry proteins that confer resistance to stem borers and rootworms. Approximately 45% of the transgenic maize planted\\u000a also contains inserted gene(s)

Bruce M. Chassy

141

Regulation of Endothelial-Specific Transgene Expression by the LacI Repressor Protein In Vivo  

PubMed Central

Genetically modified mice have played an important part in elucidating gene function in vivo. However, conclusions from transgenic studies may be compromised by complications arising from the site of transgene integration into the genome and, in inducible systems, the non-innocuous nature of inducer molecules. The aim of the present study was to use the vascular system to validate a technique based on the bacterial lac operon system, in which transgene expression can be repressed and de-repressed by an innocuous lactose analogue, IPTG. We have modified an endothelium specific promoter (TIE2) with synthetic LacO sequences and made transgenic mouse lines with this modified promoter driving expression of mutant forms of connexin40 and an independently translated reporter, EGFP. We show that tissue specificity of this modified promoter is retained in the vasculature of transgenic mice in spite of the presence of LacO sequences, and that transgene expression is uniform throughout the endothelium of a range of adult systemic and cerebral arteries and arterioles. Moreover, transgene expression can be consistently down-regulated by crossing the transgenic mice with mice expressing an inhibitor protein LacIR, and in one transgenic line, transgene expression could be de-repressed rapidly by the innocuous inducer, IPTG. We conclude that the modified bacterial lac operon system can be used successfully to validate transgenic phenotypes through a simple breeding schedule with mice homozygous for the LacIR protein. PMID:24755679

Baillie, Brett K.; Hill, Caryl E.; Matthaei, Klaus I.

2014-01-01

142

Regulation of endothelial-specific transgene expression by the LacI repressor protein in vivo.  

PubMed

Genetically modified mice have played an important part in elucidating gene function in vivo. However, conclusions from transgenic studies may be compromised by complications arising from the site of transgene integration into the genome and, in inducible systems, the non-innocuous nature of inducer molecules. The aim of the present study was to use the vascular system to validate a technique based on the bacterial lac operon system, in which transgene expression can be repressed and de-repressed by an innocuous lactose analogue, IPTG. We have modified an endothelium specific promoter (TIE2) with synthetic LacO sequences and made transgenic mouse lines with this modified promoter driving expression of mutant forms of connexin40 and an independently translated reporter, EGFP. We show that tissue specificity of this modified promoter is retained in the vasculature of transgenic mice in spite of the presence of LacO sequences, and that transgene expression is uniform throughout the endothelium of a range of adult systemic and cerebral arteries and arterioles. Moreover, transgene expression can be consistently down-regulated by crossing the transgenic mice with mice expressing an inhibitor protein LacI(R), and in one transgenic line, transgene expression could be de-repressed rapidly by the innocuous inducer, IPTG. We conclude that the modified bacterial lac operon system can be used successfully to validate transgenic phenotypes through a simple breeding schedule with mice homozygous for the LacI(R) protein. PMID:24755679

Morton, Susan K; Chaston, Daniel J; Baillie, Brett K; Hill, Caryl E; Matthaei, Klaus I

2014-01-01

143

Expression of human lactoferrin in milk of transgenic mice  

Microsoft Academic Search

The expression of human lactoferrin (hLF) in the milk of transgenic mice is described. Regulatory sequences derived from the bovine ?S1-casein gene were fused to the coding sequence of the hLF cDNA and several lines of transgenic mice were generated. Human LF RNA was detected exclusively in the mammary gland of lactating females and only after the onset of lactation.

Gerard J. Platenburg; Erika P. A. Kootwijk; Patricia M. Kooiman; Shelley L. Woloshuk; Jan H. Nuijens; Paul J. A. Krimpenfort; Frank R. Pieper; Herman A. de Boer; Rein Strijker

1994-01-01

144

Production of transgenic calves by somatic cell nuclear transfer  

Microsoft Academic Search

Bovine fetal oviduct epithelial cells were transfected with constructed double marker selective vector (pCE-EGFP-IRES-Neo-dNdB)\\u000a containing the enhanced green fluorescent protein (EGFP) and neomycin-resistant (Neor) genes by electroporation, and a transgenic cell line was obtained. Somatic cell nuclear transfer (SCNT) was carried out\\u000a using the transgenic cells as nuclei donor. A total of 424 SCNT embryos were reconstructed and 208 (49.1%)

Guochun Gong; Yunping Dai; Baoliang Fan; Huabing Zhu; Lili Wang; Haiping Wang; Bo Tang; Ying Liu; Rong Li; Rong Wan; Yinghua Huang; Ning Li

2004-01-01

145

Photoresponses of transgenic tobacco plants expressing an oat phytochrome gene  

Microsoft Academic Search

The physiological responses of transgenic tobacco (Nicotiana tabacum L.) plants that express high levels of an introduced oat (Avena sativa L.) phytochrome (phyA) gene to various light treatments are compared with those of wild-type (WT) plants. Seeds, etiolated seedlings, and light-grown plants from a homozygous transgenic tobacco line (9A4) constructed by Keller et al. (EMBO J, 8, 1005–1012, 1989) were

Alex C. McCormac; Joel R. Cherry; Howard P. Hershey; Richard D. Vierstra; Harry Smith

1991-01-01

146

L-Theanine elicits umami taste via the T1R1 + T1R3 umami taste receptor.  

PubMed

L-Theanine is a unique amino acid present in green tea. It elicits umami taste and has a considerable effect on tea taste and quality. We investigated L-theanine activity on the T1R1 + T1R3 umami taste receptor. L-Theanine activated T1R1 + T1R3-expressing cells and showed a synergistic response with inosine 5'-monophosphate. The site-directed mutagenesis analysis revealed that L-theanine binds to L-amino acid binding site in the Venus flytrap domain of T1R1. This study shows that L-theanine elicits an umami taste via T1R1 + T1R3. PMID:24633359

Narukawa, Masataka; Toda, Yasuka; Nakagita, Tomoya; Hayashi, Yukako; Misaka, Takumi

2014-06-01

147

[Generation of sugar beet transgenic plants expressing bar gene].  

PubMed

The parameters of transformation using Agrobacterium tumefaciens EHA 105 for 5 domestic sorts and lines of sugar beet (Beta vulgaris L. var. saccharifera (Alef) Krass) were optimized. The system of transgenic tissue selection based on resistance to phosphinothricin, allowing to avoid the appearing of chimeric shoots among initial transformants was developed. The transgenic plants of sugar beet sorts Ramonskaya single seed 47, L'govskaya single seed 52 and RMS 73, and LBO 17 and LBO 19 lines expressing the gene of phosphinothricin acetyl transferase bar have been obtained. The resistance of these sorts and lines to the effect of phosphinothricin in vitro has been shown. PMID:20198924

Mishutkina, Ia V; Kamionskaia, A M; Skriabin, K G

2010-01-01

148

Transgenic Hydra allow in vivo tracking of individual stem cells during morphogenesis  

PubMed Central

Understanding the evolution of development in large part relies on the study of phylogenetically old organisms. Cnidarians, such as Hydra, have become attractive model organisms for these studies. However, despite long-term efforts, stably transgenic animals could not be generated, severely limiting the functional analysis of genes. Here we report the efficient generation of transgenic Hydra lines by embryo microinjection. One of these transgenic lines expressing EGFP revealed remarkably high motility of individual endodermal epithelial cells during morphogenesis. We expect that transgenic Hydra will become important tools to dissect the molecular mechanisms of development at the base of the Metazoan tree. PMID:16556723

Wittlieb, Jörg; Khalturin, Konstantin; Lohmann, Jan U.; Anton-Erxleben, Friederike; Bosch, Thomas C. G.

2006-01-01

149

EFFECT OF AN ENHANCED CAMV 35S PROMOTER AND A FRUIT-SPECIFIC PROMOTER ON UIDA GENE EXPRESSION IN TRANSGENIC TOMATO PLANTS  

E-print Network

IN TRANSGENIC TOMATO PLANTS SERGEI F. KRASNYANSKI1 , JAGDEEP SANDHU2,3 , LESLIE L. DOMIER3,4 , DENNIS E. BUETOW2 plants. In order to generate sufficient numbers of transgenic tomato plants, both a reliable regeneration collected from T0 and T1 plants, and assayed for b-glucuronidase (GUS) enzyme activity. As expected, both

Korban, Schuyler S.

150

Nonapoptotic neurodegeneration in a transgenic mouse model of Huntington's disease  

E-print Network

, degeneration can eventually appear throughout the brain (2). In cases with juvenile onset ( 20 years of age polyglutamine repeat. We have developed several lines of mice that are transgenic for exon 1 of the HD gene lines of these mice develop a late onset neurode- generation within the anterior cingulate cortex

151

Two Distinct Determinants of Ligand Specificity in T1R1/T1R3 (the Umami Taste Receptor)*  

PubMed Central

Umami taste perception in mammals is mediated by a heteromeric complex of two G-protein-coupled receptors, T1R1 and T1R3. T1R1/T1R3 exhibits species-dependent differences in ligand specificity; human T1R1/T1R3 specifically responds to l-Glu, whereas mouse T1R1/T1R3 responds more strongly to other l-amino acids than to l-Glu. The mechanism underlying this species difference remains unknown. In this study we analyzed chimeric human-mouse receptors and point mutants of T1R1/T1R3 and identified 12 key residues that modulate amino acid recognition in the human- and mouse-type responses in the extracellular Venus flytrap domain of T1R1. Molecular modeling revealed that the residues critical for human-type acidic amino acid recognition were located at the orthosteric ligand binding site. In contrast, all of the key residues for the mouse-type broad response were located at regions outside of both the orthosteric ligand binding site and the allosteric binding site for inosine-5?-monophosphate (IMP), a known natural umami taste enhancer. Site-directed mutagenesis demonstrated that the newly identified key residues for the mouse-type responses modulated receptor activity in a manner distinct from that of the allosteric modulation via IMP. Analyses of multiple point mutants suggested that the combination of two distinct determinants, amino acid selectivity at the orthosteric site and receptor activity modulation at the non-orthosteric sites, may mediate the ligand specificity of T1R1/T1R3. This hypothesis was supported by the results of studies using nonhuman primate T1R1 receptors. A complex molecular mechanism involving changes in the properties of both the orthosteric and non-orthosteric sites of T1R1 underlies the determination of ligand specificity in mammalian T1R1/T1R3. PMID:24214976

Toda, Yasuka; Nakagita, Tomoya; Hayakawa, Takashi; Okada, Shinji; Narukawa, Masataka; Imai, Hiroo; Ishimaru, Yoshiro; Misaka, Takumi

2013-01-01

152

Genetic and Biochemical Dissection of Transgenic RNA-Mediated Virus Resistance  

Microsoft Academic Search

RNA-mediated virus resistance has been observed in transgenic plants at varying frequencies, suggesting that a nuclear requirement or other pre-condition must be met. This study was undertaken to characterize genetically transgenes that confer a highly resistant state to infection by tobacco etch virus (TEV). Transgenic tobacco line 2RC-6.13, expressing an untranslatable mRNA containing the TEV coat protein open reading frame,

Joel Goodwin; Kelly Chapman; Sherri Swaney; T. Dawn Parks; Earl A. Wernsman; William G. DoughertyaYc

1996-01-01

153

Transgenics in crops  

NASA Technical Reports Server (NTRS)

With rapid world population growth and declining availability of fresh water and arable land, a new technology is urgently needed to enhance agricultural productivity. Recent discoveries in the field of crop transgenics clearly demonstrate the great potential of this technology for increasing food production and improving food quality while preserving the environment for future generations. In this review, we briefly discuss some of the recent achievements in crop improvement that have been made using gene transfer technology.

Li, Y.; Wu, Y. H.; McAvoy, R.; Duan, H.

2001-01-01

154

T1-mapping in the heart: accuracy and precision  

PubMed Central

The longitudinal relaxation time constant (T1) of the myocardium is altered in various disease states due to increased water content or other changes to the local molecular environment. Changes in both native T1 and T1 following administration of gadolinium (Gd) based contrast agents are considered important biomarkers and multiple methods have been suggested for quantifying myocardial T1 in vivo. Characterization of the native T1 of myocardial tissue may be used to detect and assess various cardiomyopathies while measurement of T1 with extracellular Gd based contrast agents provides additional information about the extracellular volume (ECV) fraction. The latter is particularly valuable for more diffuse diseases that are more challenging to detect using conventional late gadolinium enhancement (LGE). Both T1 and ECV measures have been shown to have important prognostic significance. T1-mapping has the potential to detect and quantify diffuse fibrosis at an early stage provided that the measurements have adequate reproducibility. Inversion recovery methods such as MOLLI have excellent precision and are highly reproducible when using tightly controlled protocols. The MOLLI method is widely available and is relatively mature. The accuracy of inversion recovery techniques is affected significantly by magnetization transfer (MT). Despite this, the estimate of apparent T1 using inversion recovery is a sensitive measure, which has been demonstrated to be a useful tool in characterizing tissue and discriminating disease. Saturation recovery methods have the potential to provide a more accurate measurement of T1 that is less sensitive to MT as well as other factors. Saturation recovery techniques are, however, noisier and somewhat more artifact prone and have not demonstrated the same level of reproducibility at this point in time. This review article focuses on the technical aspects of key T1-mapping methods and imaging protocols and describes their limitations including the factors that influence their accuracy, precision, and reproducibility. PMID:24387626

2014-01-01

155

Assessment of the diversity and dynamics of Plum pox virus and aphid populations in transgenic European plums under Mediterranean conditions.  

PubMed

The molecular variability of Plum pox virus (PPV) populations was compared in transgenic European plums (Prunus domestica L.) carrying the coat protein (CP) gene of PPV and non-transgenic plums in an experimental orchard in Valencia, Spain. A major objective of this study was to detect recombination between PPV CP transgene transcripts and infecting PPV RNA. Additionally, we assessed the number and species of PPV aphid vectors that visited transgenic and non-transgenic plum trees. Test trees consisted of five different P. domestica transgenic lines, i.e. the PPV-resistant C5 'HoneySweet' line and the PPV-susceptible C4, C6, PT6 and PT23 lines, and non-transgenic P. domestica and P. salicina Lind trees. No significant difference in the genetic diversity of PPV populations infecting transgenic and conventional plums was detected, in particular no recombinant between transgene transcripts and incoming viral RNA was found at detectable levels. Also, no significant difference was detected in aphid populations, including viruliferous individuals, that visited transgenic and conventional plums. Our data indicate that PPV-CP transgenic European plums exposed to natural PPV infection over an 8 year period caused limited, if any, risk beyond the cultivation of conventional plums under Mediterranean conditions in terms of the emergence of recombinant PPV and diversity of PPV and aphid populations. PMID:17605085

Capote, Nieves; Pérez-Panadés, Jordi; Monzó, César; Carbonell, Emilio; Urbaneja, Alberto; Scorza, Ralph; Ravelonandro, Michel; Cambra, Mariano

2008-06-01

156

Product Jahn-Teller systems: The \\{T1?H\\}?(g+2h) icosahedral exciton  

NASA Astrophysics Data System (ADS)

The \\{T1?H\\}?(g+2h) product Jahn-Teller (JT) system offers a model Hamiltonian for the excited configuration of C60. It describes the combined JT activity of two open shells transforming as the threefold and fivefold degenerate icosahedral representations T1 and H. The two separate JT problems interfere via the interaction with common vibrational modes. In this paper we examine the structure of the resulting potential energy surface. The treatment first considers the simplified \\{T1?H\\}?(2h) problem. The coupling conditions for this problem can be represented in a two-dimensional phase diagram with a rich structure. The diagram is separated in four domains by four trough lines. These correspond to different embeddings of SO(3) in SO(5) and describe the possible spherical couplings between a three vector and a five tensor. Outside the trough lines symmetry is broken to D5d, D3d, D2h, and even C2h. Several tables offer a description of the structural aspects of these low-symmetry solutions. In the second part the full multimode Hamiltonian is treated by the method of the isostationary function. It is shown that the interconfigurational coupling term of this Hamiltonian reduces to the same tensorial form as for the simplified single mode \\{T1?H\\}?(2h) case.

Qiu, Q. C.; Chibotaru, L. F.; Ceulemans, A.

2002-01-01

157

Analysis of Rice Act1 5[prime] Region Activity in Transgenic Rice Plants  

Microsoft Academic Search

The 5' region of the rice actin 1 gene (Actl) has been developed as an efficient regulator of foreign gene expression in transgenic rice plants. To determine the pattern and level of rice Actl 5' region activity, transgenic rice plants containing the Actl 5' region fused to a bacterial 8-glucuronidase (Gus) coding sequence were generated. Two independent clonal lines of

Wanggen Zhang; David McElroy; Ray WU

1991-01-01

158

Two Amyloid Precursor Protein Transgenic Mouse Models with Alzheimer Disease-Like Pathology  

Microsoft Academic Search

Mutations in the amyloid precursor protein (APP) gene cause early-onset familial Alzheimer disease (AD) by affecting the formation of the amyloid beta (Abeta ) peptide, the major constituent of AD plaques. We expressed human APP751 containing these mutations in the brains of transgenic mice. Two transgenic mouse lines develop pathological features reminiscent of AD. The degree of pathology depends on

Christine Sturchler-Pierrat; Dorothee Abramowski; Mairead Duke; Karl-Heinz Wiederhold; Claudia Mistl; Sabin Rothacher; Brigit Ledermann; Kurt Burki; Peter Frey; Paolo A. Paganetti; Caroline Waridel; Michael E. Calhoun; Mathias Jucker; Alphonse Probst; Matthias Staufenbiel; Bernd Sommer

1997-01-01

159

Ectopic over-expression of peroxisomal ascorbate peroxidase (SbpAPX) gene confers salt stress tolerance in transgenic peanut (Arachis hypogaea).  

PubMed

Peroxisomal ascorbate peroxidase gene (SbpAPX) of an extreme halophyte Salicornia brachiata imparts abiotic stress endurance and plays a key role in the protection against oxidative stress. The cloned SbpAPX gene was transformed to local variety of peanut and about 100 transgenic plants were developed using optimized in vitro regeneration and Agrobacterium mediated genetic transformation method. The T0 transgenic plants were confirmed for the gene integration; grown under controlled condition in containment green house facility; seeds were harvested and T1 plants were raised. Transgenic plants (T1) were further confirmed by PCR using gene specific primers and histochemical GUS assay. About 40 transgenic plants (T1) were selected randomly and subjected for salt stress tolerance study. Transgenic plants remained green however non-transgenic plants showed bleaching and yellowish leaves under salt stress conditions. Under stress condition, transgenic plants continued normal growth and completed their life cycle. Transgenic peanut plants exhibited adequate tolerance under salt stress condition and thus could be explored for the cultivation in salt affected areas for the sustainable agriculture. PMID:24954532

Singh, Natwar; Mishra, Avinash; Jha, Bhavanath

2014-08-15

160

T1R3: A human calcium taste receptor  

PubMed Central

Many animals can detect the taste of calcium but it is unclear how or whether humans have this ability. We show here that calcium activates hTAS1R3-transfected HEK293 cells and that this response is attenuated by lactisole, an inhibitor of hT1R3. Moreover, trained volunteers report that lactisole reduces the calcium intensity of calcium lactate. Thus, humans can detect calcium by taste, T1R3 is a receptor responsible for this, and lactisole can reduce the taste perception of calcium by acting on T1R3. PMID:22773945

Tordoff, Michael G.; Alarcon, Laura K.; Valmeki, Sitaram; Jiang, Peihua

2012-01-01

161

Insect-resistant transgenic plants  

Microsoft Academic Search

The technology of insect-resistant transgenic plants is expanding very rapidly, with considerable research activity in both the private and public sectors. The only commercialized insect-resistant transgenic plants to date express genes derived from the bacterium Bacillus thuringiensis, but a wide range of genes from higher plants have also been transferred into crop cultivars, especially genes encoding inhibitors of digestive enzymes

Tanja H Schuler; Guy M Poppy; Brian R Kerry; Ian Denholm

1998-01-01

162

Pathology waste includes: Transgenic animals.  

E-print Network

Collection" form. · We will pick up your waste within 1-3 days. University of California, IrvinePathology waste includes: · Transgenic animals. · Potentially transgenic animals including, "no of as a hazardous chemical waste. The tissues or carcasses can then be disposed of as pathology waste. Labeling

George, Steven C.

163

A thermoalkaliphilic lipase of Geobacillus sp. T1.  

PubMed

A thermoalkaliphilic T1 lipase gene of Geobacillus sp. strain T1 was overexpressed in pGEX vector in the prokaryotic system. Removal of the signal peptide improved protein solubility and promoted the binding of GST moiety to the glutathione-Sepharose column. High-yield purification of T1 lipase was achieved through two-step affinity chromatography with a final specific activity and yield of 958.2 U/mg and 51.5%, respectively. The molecular mass of T1 lipase was determined to be approximately 43 kDa by gel filtration chromatography. T1 lipase had an optimum temperature and pH of 70 degrees C and pH 9, respectively. It was stable up to 65 degrees C with a half-life of 5 h 15 min at pH 9. It was stable in the presence of 1 mM metal ions Na(+), Ca(2+), Mn(2+), K(+) and Mg(2+ ), but inhibited by Cu(2+), Fe(3+) and Zn(2+). Tween 80 significantly enhanced T1 lipase activity. T1 lipase was active towards medium to long chain triacylglycerols (C10-C14) and various natural oils with a marked preference for trilaurin (C12) (triacylglycerol) and sunflower oil (natural oil). Serine and aspartate residues were involved in catalysis, as its activity was strongly inhibited by 5 mM PMSF and 1 mM Pepstatin. The T(m) for T1 lipase was around 72.2 degrees C, as revealed by denatured protein analysis of CD spectra. PMID:17426920

Leow, Thean Chor; Rahman, Raja Noor Zaliha Raja Abd; Basri, Mahiran; Salleh, Abu Bakar

2007-05-01

164

Ectopic Overexpression of Asparagine Synthetase in Transgenic Tobacco.  

PubMed

Here, we monitor the effects of ectopic overexpression of genes for pea asparagine synthetase (AS1) in transgenic tobacco (Nicotiana tabacum). The AS genes of pea and tobacco are normally expressed only during the dark phase of the diurnal growth cycle and specifically in phloem cells. A hybrid gene was constructed in which a pea AS1 cDNA was fused to the cauliflower mosaic virus 35S promoter. The 35S-AS1 gene was therefore ectopically expressed in all cell types in transgenic tobacco and constitutively expressed at high levels in both the light and the dark. Northern analysis demonstrated that the 35S-AS1 transgene was constitutively expressed at high levels in leaves of several independent transformants. Furthermore, amino acid analysis revealed a 10- to 100-fold increase in free asparagine in leaves of transgenic 35S-AS1 plants (construct z127) compared with controls. Plant growth analyses showed increases (although statistically insignificant) in growth phenotype during the vegetative stage of growth in 35S-AS1 transgenic lines. The 35S-AS1 construct was further modified by deletion of the glutamine-binding domain of the enzyme (gln[delta]AS1; construct z167). By analogy to animal AS, we reasoned that inhibition of glutamine-dependent AS activity might enhance the ammonia-dependent AS activity. The 3- to 19-fold increase in asparagine levels in the transgenic plants expressing gln[delta]AS1 compared with wild type suggests that the novel AS holoenzyme present in the transgenic plants (gln[delta]AS1 homodimer) has enhanced ammonia-dependent activity. These data indicate that manipulation of AS expression in transgenic plants causes an increase in nitrogen assimilation into asparagine, which in turn produces effects on plant growth and asparagine biosynthesis. PMID:12232020

Brears, T.; Liu, C.; Knight, T. J.; Coruzzi, G. M.

1993-12-01

165

A 5' differentially methylated sequence and the 3'-flanking region are necessary for H19 transgene imprinting.  

PubMed Central

The mouse H19 gene is expressed exclusively from the maternal allele. The imprinted expression of the endogenous gene can be recapitulated in mice by using a 14-kb transgene encompassing 4 kb of 5'-flanking sequence, 8 kb of 3'-flanking sequence, which includes the two endoderm-specific enhancers, and an internally deleted structural gene. We have generated multiple transgenic lines with this 14-kb transgene and found that high-copy-number transgenes most closely follow the imprinted expression of the endogenous gene. To determine which sequences are important for imprinted expression, deletions were introduced into the transgene. Deletion of the 5' region, where a differentially methylated sequence proposed to be important in determining parental-specific expression is located, resulted in transgenes that were expressed and hypomethylated, regardless of parental origin. A 6-kb transgene, which contains most of the differentially methylated sequence but lacks the 8-kb 3' region, was not expressed and also not methylated. These results indicate that expression of either the H19 transgene or a 3' DNA sequence is key to establishing the differential methylation pattern observed at the endogenous locus. Finally, methylation analysis of transgenic sperm DNA from the lines that are not imprinted reveals that the transgenes are not capable of establishing and maintaining the paternal methylation pattern observed for imprinted transgenes and the endogenous paternal allele. Thus, the imprinting of the H19 gene requires a complex set of elements including the region of differential methylation and the 3'-flanking sequence. PMID:8972211

Elson, D A; Bartolomei, M S

1997-01-01

166

Cre/lox system to develop selectable marker free transgenic tobacco plants conferring resistance against sap sucking homopteran insect.  

PubMed

A binary expression vector was constructed containing the insecticidal gene Allium sativum leaf agglutinin (ASAL), and a selectable nptII marker gene cassette, flanked by lox sites. Similarly, another binary vector was developed with the chimeric cre gene construct. Transformed tobacco plants were generated with these two independent vectors. Each of the T(0) lox plants was crossed with T(0) Cre plants. PCR analyses followed by the sequencing of the target T-DNA part of the hybrid T(1) plants demonstrated the excision of the nptII gene in highly precised manner in certain percentage of the T(1) hybrid lines. The frequency of such marker gene excision was calculated to be 19.2% in the hybrids. Marker free plants were able to express ASAL efficiently and reduce the survivability of Myzus persiceae, the deadly pest of tobacco significantly, compared to the control tobacco plants. Results of PCR and Southern blot analyses of some of the T(2) plants detected the absence of cre as well as nptII genes. Thus, the crossing strategy involving Cre/lox system for the excision of marker genes appears to be very effective and easy to execute. Documentation of such marker excision phenomenon in the transgenic plants expressing the important insecticidal protein for the first time has a great significance from agricultural and biotechnological points of view. PMID:18663453

Chakraborti, Dipankar; Sarkar, Anindya; Mondal, Hossain A; Schuermann, David; Hohn, Barbara; Sarmah, Bidyut K; Das, Sampa

2008-10-01

167

Photoresponses of transgenic tobacco plants expressing an oat phytochrome gene.  

PubMed

The physiological responses of transgenic tobacco (Nicotiana tabacum L.) plants that express high levels of an introduced oat (Avena sativa L.) phytochrome (phyA) gene to various light treatments are compared with those of wild-type (WT) plants. Seeds, etiolated seedlings, and light-grown plants from a homozygous transgenic tobacco line (9A4) constructed by Keller et al. (EMBO J, 8, 1005-1012, 1989) were treated with red (R), far-red (FR), or white light (WL) with or without supplemental FR light, revealing major perturbations of the normal photobiological responses. White light stimulated germination of both WT and transgenic seed, but addition of FR to the WL treatment suppressed germination. In the WT, all fluence rates tested inhibited germination, but in the transgenics, reduction effluence rate partially relieved germination from the FR-mediated inhibition. It is suggested that the higher absolute levels of the FR-absorbing form of phytochrome (Pfr) in the irradiated transgenics, compared to the WT, may be responsible for the reduced FR-mediated inhibition of germination in the former. Hypocotyl extension of dark-grown seedlings of both WT and transgenic lines was inhibited by continuous R or FR irradiation, typical of the high-irradiance response (HIR). After 2 d of de-etiolation in WL, the WT seedlings had lost the FR-mediated inhibition of hypocotyl extension, whereas it was retained in the transgenics. The FR-mediated inhibition of hypocotyl extension in the transgenic seedlings after de-etiolation may reflect the persistence of an, FR-HIR response mediated by the overexpressed oat PhyA phytochrome. Light-grown WT seedlings exhibited typical shade-avoidance responses when treated with WL supplemented with high levels of FR radiation. Internode and petiole extension rates were markedly increased, and the chlorophyll a?b ratio decreased, in the low-R: FR treatment. The transgenics, however, showed no increases in extension growth under low-R: FR treatments, and at low fluence rates both internode and petiole extension rates were significantly decreased by low R ? FR. Interpretation of these data is difficult. The depression of the chlorophyll a?b ratio by low R ? FR was identical in WT and transgenic plants, indicating that not all shade-avoidance responses of light-grown plants were disrupted by the over-expression of the introduced oat phyA gene. The results are discussed in relation to the proposal that different members of the phytochrome family may have different physiological roles. PMID:24186338

McCormac, A C; Cherry, J R; Hershey, H P; Vierstra, R D; Smith, H

1991-09-01

168

The chicken skeletal muscle alpha-actin promoter is tissue specific in transgenic mice.  

PubMed Central

We have generated transgenic mouse lines that carry the promoter region of the chicken skeletal muscle alpha (alpha sk) actin gene linked to the bacterial chloramphenicol acetyltransferase (CAT) gene. In adult mice, the pattern of transgene expression resembled that of the endogenous alpha sk actin gene. In most of the transgenic lines, high levels of CAT activity were detected in striated muscle (skeletal and cardiac) but not in the other tissues tested. In striated muscle, transcription of the transgene was initiated at the normal transcriptional start site of the chicken alpha sk actin gene. The region from nucleotides -191 to +27 of the chicken alpha sk actin gene was sufficient to direct the expression of CAT in striated muscle of transgenic mice. These observations suggest that the mechanism of tissue-specific actin gene expression is well conserved in higher vertebrate species. Images PMID:2779567

Petropoulos, C J; Rosenberg, M P; Jenkins, N A; Copeland, N G; Hughes, S H

1989-01-01

169

Generation of large numbers of transgenic Kentucky bluegrass (Poa pratensis L.) plants following biolistic gene transfer.  

PubMed

A very efficient transformation system, using biolistic bombardment, has been developed for the production of transgenic plants of Kentucky bluegrass (Poa pratensis L.). Embryogenic calli, initiated from immature embryos, were transformed either with pAct1IHPT-4 containing the hygromycin phosphotransferase (hpt) gene or with pDM803 containing the phosphinothricin acetyltransferase (bar) gene and the beta-glucuronidase (uidA) gene. In total 119 independent transgenic plants were recovered from 153 hygromycin-resistant lines. Bialaphos selection yielded a total of 99 bialaphos-resistant lines and from these 34 independent transgenic plants were recovered. Southern blot analysis demonstrated the independent nature of the transgenic plants and also revealed a complex transgene integration pattern with multiple insertions. PMID:16328388

Gao, Caixia; Jiang, Li; Folling, Marianne; Han, Liebao; Nielsen, Klaus Kristian

2006-02-01

170

Transgenic tobacco plants expressing the maize Cat2 gene have altered catalase levels that affect plant-pathogen interactions and resistance to oxidative stress  

Microsoft Academic Search

Transgenic tobacco genotypes expressing the maize Cat2 gene were developed with altered catalase (CAT) levels that resulted in a moderate increase of CAT activity in two transgenic lines. Bacterial infection, with a pathogen that does not share homology with the transgene, caused local and systemic down-regulation of the steady state mRNA levels of the 35S-driven transgene in a manner resembling

A. N. Polidoros; P. V. Mylona; J. G. Scandalios

2001-01-01

171

Resetting Central and Peripheral Circadian Oscillators in Transgenic Rats  

Microsoft Academic Search

In multicellular organisms, circadian oscillators are organized into multitissue systems which function as biological clocks that regulate the activities of the organism in relation to environmental cycles and provide an internal temporal framework. To investigate the organization of a mammalian circadian system, we constructed a transgenic rat line in which luciferase is rhythmically expressed under the control of the mouse

Shin Yamazaki; Rika Numano; Michikazu Abe; Akiko Hida; Ri-ichi Takahashi; Masatsugu Ueda; Gene D. Block; Yoshiyuki Sakaki; Michael Menaker; Hajime Tei

2000-01-01

172

Striatal Transplantation in a Transgenic Mouse Model of Huntington's Disease  

Microsoft Academic Search

Striatal grafts have been proposed as a potential strategy for striatal repair in Huntington's disease, but it is unknown whether the diseased brain will compromise graft survival. A transgenic mouse line has recently been described in which hemizygotes with an expanded CAG repeat in exon 1 of the HD gene exhibit a progressive neurological phenotype similar to the motor symptoms

S. B. Dunnett; R. J. Carter; C. Watts; E. M. Torres; A. Mahal; L. Mangiarini; G. Bates; A. J. Morton

1998-01-01

173

Hyperpolarized (129)Xe T (1) in oxygenated and deoxygenated blood  

NASA Technical Reports Server (NTRS)

The viability of the new technique of hyperpolarized (129)Xe MRI (HypX-MRI) for imaging organs other than the lungs depends on whether the spin-lattice relaxation time, T(1), of (129)Xe is sufficiently long in the blood. In previous experiments by the authors, the T(1) was found to be strongly dependent upon the oxygenation of the blood, with T(1) increasing from about 3 s in deoxygenated samples to about 10 s in oxygenated samples. Contrarily, Tseng et al. (J. Magn. Reson. 1997; 126: 79-86) reported extremely long T(1) values deduced from an indirect experiment in which hyperpolarized (129)Xe was used to create a 'blood-foam'. They found that oxygenation decreased T(1). Pivotal to their experiment is the continual and rapid exchange of hyperpolarized (129)Xe between the gas phase (within blood-foam bubbles) and the dissolved phase (in the skin of the bubbles); this necessitated a complicated analysis to extract the T(1) of (129)Xe in blood. In the present study, the experimental design minimizes gas exchange after the initial bolus of hyperpolarized (129)Xe has been bubbled through the sample. This study confirms that oxygenation increases the T(1) of (129)Xe in blood, from about 4 s in freshly drawn venous blood, to about 13 s in blood oxygenated to arterial levels, and also shifts the red blood cell resonance to higher frequency. Copyright 2000 John Wiley & Sons, Ltd. Abbreviations used BOLD blood oxygen level dependent NOE nuclear overhouses effect PO(2) oxygen partial pressure RBC red blood cells RF radio frequency SNR signal-to-noise ratio.

Albert, M. S.; Balamore, D.; Kacher, D. F.; Venkatesh, A. K.; Jolesz, F. A.

2000-01-01

174

Next-generation transgenic mice for optogenetic analysis of neural circuits  

E-print Network

Here we characterize several new lines of transgenic mice useful for optogenetic analysis of brain circuit function. These mice express optogenetic probes, such as enhanced halorhodopsin or several different versions of ...

Asrican, Brent

175

[Transgenics without Manichaeism].  

PubMed

We live in an era characterized by the hegemony of science and technology, an era fraught with questions awaiting answers which would enable a safe and sustainable future for humankind. The development of agro-industrial processes - food products in particular - through recombinant DNA technology has enhanced the profit prospects of the few big biotechnology companies and of large-scale farmers who have access to the latest technological developments. We thus oppose a moratorium on recombinant DNA technology. Moreover, hasty statements about risk-free transgenics may be misleading in the absence of extensive safety tests. There is a pressing need for the establishment of biosafety policy in this country involving the organized civil society and every government agency responsible for monitoring such matters. There is also the need to put in place a bio-surveillance and a code of ethics regarding genetic manipulation. PMID:16680900

Valle, S

2000-01-01

176

Transgenic mice: beyond the knockout  

PubMed Central

Transgenic mice have had a tremendous impact on biomedical research. Most researchers are familiar with transgenic mice that carry Cre recombinase (Cre) and how they are used to create conditional knockouts. However, some researchers are less familiar with many of the other types of transgenic mice and their applications. For example, transgenic mice can be used to study biochemical and molecular pathways in primary cultures and cell suspensions derived from transgenic mice, cell-cell interactions using multiple fluorescent proteins in the same mouse, and the cell cycle in real time and in the whole animal, and they can be used to perform deep tissue imaging in the whole animal, follow cell lineage during development and disease, and isolate large quantities of a pure cell type directly from organs. These novel transgenic mice and their applications provide the means for studying of molecular and biochemical events in the whole animal that was previously limited to cell cultures. In conclusion, transgenic mice are not just for generating knockouts. PMID:21068085

2011-01-01

177

Chitinase activities, scab resistance, mycorrhization rates and biomass of own-rooted and grafted transgenic apple  

PubMed Central

This study investigated the impact of constitutively expressed Trichoderma atroviride genes encoding exochitinase nag70 or endochitinase ech42 in transgenic lines of the apple cultivar Pinova on the symbiosis with arbuscular mycorrhizal fungi (AMF). We compared the exo- and endochitinase activities of leaves and roots from non-transgenic Pinova and the transgenic lines T386 and T389. Local and systemic effects were examined using own-rooted trees and trees grafted onto rootstock M9. Scab susceptibility was also assessed in own-rooted and grafted trees. AMF root colonization was assessed microscopically in the roots of apple trees cultivated in pots with artificial substrate and inoculated with the AMF Glomus intraradices and Glomus mosseae. Own-rooted transgenic lines had significantly higher chitinase activities in their leaves and roots compared to non-transgenic Pinova. Both of the own-rooted transgenic lines showed significantly fewer symptoms of scab infection as well as significantly lower root colonization by AMF. Biomass production was significantly reduced in both own-rooted transgenic lines. Rootstock M9 influenced chitinase activities in the leaves of grafted scions. When grafted onto M9, the leaf chitinase activities of non-transgenic Pinova (M9/Pinova) and transgenic lines (M9/T386 and M9/T389) were not as different as when grown on their own roots. M9/T386 and M9/T389 were only temporarily less infected by scab than M9/Pinova. M9/T386 and M9/T389 did not differ significantly from M9/Pinova in their root chitinase activities, AMF root colonization and biomass. PMID:22888297

Schäfer, Tina; Hanke, Magda-Viola; Flachowsky, Henryk; König, Stephan; Peil, Andreas; Kaldorf, Michael; Polle, Andrea; Buscot, François

2012-01-01

178

Transgenic maize endosperm containing a milk protein has improved amino acid balance.  

PubMed

In order to meet the protein nutrition needs of the world population, greater reliance on plant protein sources will become necessary. The amino acid balance of most plant protein sources does not match the nutritional requirements of monogastric animals, limiting their nutritional value. In cereals, the essential amino acid lysine is deficient. Maize is a major component of human and animal diets worldwide and especially where sources of plant protein are in critical need such as sub-Saharan Africa. To improve the amino acid balance of maize, we developed transgenic maize lines that produce the milk protein alpha-lactalbumin in the endosperm. Lines in which the transgene was inherited as a single dominant genetic locus were identified. Sibling kernels with or without the transgene were compared to determine the effect of the transgene on kernel traits in lines selected for their high content of alpha-lactalbumin. Total protein content in endosperm from transgene positive kernels was not significantly different from total protein content in endosperm from transgene negative kernels in three out of four comparisons, whereas the lysine content of the lines examined was 29-47% greater in endosperm from transgene positive kernels. The content of some other amino acids was changed to a lesser extent. Taken together, these changes resulted in the transgenic endosperms having an improved amino acid balance relative to non-transgenic endosperms produced on the same ear. Kernel appearance, weight, density and zein content did not exhibit substantial differences in kernels expressing the transgene when compared to non-expressing siblings. Assessment of the antigenicity and impacts on animal health will be required in order to determine the overall value of this technology. PMID:17387628

Bicar, Earl H; Woodman-Clikeman, Wendy; Sangtong, Varaporn; Peterson, Joan M; Yang, S Samuel; Lee, Michael; Scott, M Paul

2008-02-01

179

The biology of mammary transgenes: Five rules  

Microsoft Academic Search

The development of hyperplasias, dysplasias, and mammary tumors has been studied extensively in transgenic mice. It is now becoming clear that transgenes activate and participate in oncogenic pathways that govern the events surrounding neoplastic progression in transgenic mice. The oncogenic pathways control mammary growth, development, and neoplastic progression. Some of the key features of transgenic biology can be expressed in

Robert D. Cardiff

1996-01-01

180

Development of transgenic animals for optogenetic manipulation of mammalian nervous system function: Progress and prospects for behavioral neuroscience  

PubMed Central

Here we review the rapidly growing toolbox of transgenic mice and rats that exhibit functional expression of engineered opsins for neuronal activation and silencing with light. Collectively, these transgenic animals are enabling neuroscientists to access and manipulate the many diverse cell types in the mammalian nervous system in order to probe synaptic and circuitry connectivity, function, and dysfunction. The availability of transgenic lines affords important advantages such as stable and heritable transgene expression patterns across experimental cohorts. As such, the use of transgenic lines precludes the need for other costly and labor-intensive procedures to achieve functional transgene expression in each individual experimental animal. This represents an important consideration when large cohorts of experimental animals are desirable as in many common behavioral assays. We describe the diverse strategies that have been implemented for developing transgenic mouse and rat lines and highlight recent advances that have led to dramatic improvements in achieving functional transgene expression of engineered opsins. Furthermore, we discuss considerations and caveats associated with implementing recently developed transgenic lines for optogenetics-based experimentation. Lastly, we propose strategies that can be implemented to develop and refine the next generation of genetically modified animals for behaviorally-focused optogenetics-based applications. PMID:23473879

Ting, Jonathan T.; Feng, Guoping

2014-01-01

181

Transgenic Mosquitoes Expressing a Phospholipase A2 Gene Have a Fitness Advantage When Fed Plasmodium falciparum-Infected Blood  

PubMed Central

Background Genetically modified mosquitoes have been proposed as an alternative strategy to reduce the heavy burden of malaria. In recent years, several proof-of-principle experiments have been performed that validate the idea that mosquitoes can be genetically modified to become refractory to malaria parasite development. Results We have created two transgenic lines of Anophelesstephensi, a natural vector of Plasmodium falciparum, which constitutively secrete a catalytically inactive phospholipase A2 (mPLA2) into the midgut lumen to interfere with Plasmodium ookinete invasion. Our experiments show that both transgenic lines expressing mPLA2 significantly impair the development of rodent malaria parasites, but only one line impairs the development of human malaria parasites. In addition, when fed on malaria-infected blood, mosquitoes from both transgenic lines are more fecund than non-transgenic mosquitoes. Consistent with these observations, cage experiments with mixed populations of transgenic and non-transgenic mosquitoes show that the percentage of transgenic mosquitoes increases when maintained on Plasmodium-infected blood. Conclusions Our results suggest that the expression of an anti-Plasmodium effector gene gives transgenic mosquitoes a fitness advantage when fed malaria-infected blood. These findings have important implications for future applications of transgenic mosquito technology in malaria control. PMID:24098427

Smith, Ryan C.; Kizito, Christopher; Rasgon, Jason L.; Jacobs-Lorena, Marcelo

2013-01-01

182

Transgene x Environment Interactions in Genetically Modified Wheat  

PubMed Central

Background The introduction of transgenes into plants may cause unintended phenotypic effects which could have an impact on the plant itself and the environment. Little is published in the scientific literature about the interrelation of environmental factors and possible unintended effects in genetically modified (GM) plants. Methods and Findings We studied transgenic bread wheat Triticum aestivum lines expressing the wheat Pm3b gene against the fungus powdery mildew Blumeria graminis f.sp. tritici. Four independent offspring pairs, each consisting of a GM line and its corresponding non-GM control line, were grown under different soil nutrient conditions and with and without fungicide treatment in the glasshouse. Furthermore, we performed a field experiment with a similar design to validate our glasshouse results. The transgene increased the resistance to powdery mildew in all environments. However, GM plants reacted sensitive to fungicide spraying in the glasshouse. Without fungicide treatment, in the glasshouse GM lines had increased vegetative biomass and seed number and a twofold yield compared with control lines. In the field these results were reversed. Fertilization generally increased GM/control differences in the glasshouse but not in the field. Two of four GM lines showed up to 56% yield reduction and a 40-fold increase of infection with ergot disease Claviceps purpurea compared with their control lines in the field experiment; one GM line was very similar to its control. Conclusions Our results demonstrate that, depending on the insertion event, a particular transgene can have large effects on the entire phenotype of a plant and that these effects can sometimes be reversed when plants are moved from the glasshouse to the field. However, it remains unclear which mechanisms underlie these effects and how they may affect concepts in molecular plant breeding and plant evolutionary ecology. PMID:20635001

Zeller, Simon L.; Kalinina, Olena; Brunner, Susanne; Keller, Beat; Schmid, Bernhard

2010-01-01

183

Japanese quail: an efficient animal model for the production of transgenic avians.  

PubMed

The ability to generate transgenic mice has been a powerful tool in studying functional genomics, and much of our knowledge about developmental biology has come from the study of chicken embryology. Unfortunately, the availability of molecular genetic techniques, such as transgenics and knockouts, has been limited for developmental biologists using avian animal models. Efforts to develop a system for the rapid production of transgenic chickens have met with many obstacles, including high animal husbandry costs and long generational times. Recently, the Japanese quail has proven to be an excellent model organism for the production of transgenic avians using lentiviral vectors. The relatively small size of the adults, short time to sexual maturity, and prodigious egg production of the Japanese quail make development of transgenic lines less labor- and space-intensive compared to chickens. The high degree of homology between chicken and quail genomes allows researchers to design highly specific DNA constructs for the production of transgenic birds. In addition, transgenic quail offer all of the advantages of the classic avian developmental model system, such as the ability to readily produce quail:chick transplant chimeras. Finally, Japanese quail are ideal for in ovo imaging of embryos expressing fluorescent reporters introduced from a transgene and/or electroporation. Here, we provide detailed methods for generating transgenic quail using high-titer lentivirus. PMID:20147007

Poynter, Greg; Huss, David; Lansford, Rusty

2009-01-01

184

Transgenic Models for the Study of Lung Antioxidant Defense: Enhanced Manganese-containing Superoxide Dismutase Activity Gives Partial Protection to B6C3 Hybrid Mice Exposed to Hyperoxia  

Microsoft Academic Search

To investigate the role of manganese-containing superoxide dismutase (MnSOD) in lung antioxidant de- fense, lines of transgenic B6C3 hybrid mice carrying human MnSOD transgenes under the transcriptional control of a human b -actin promoter were established. Expression studies demonstrated that the human MnSOD transgene in line TgHMS66 is expressed and functional. The cellular distribution of the transgene product in the

Ye-Shih Ho; Renaud Vincent; Margaret S. Dey; Jan W. Slot; James D. Crapo

1998-01-01

185

Consistent transcriptional silencing of 35S-driven transgenes in gentian.  

PubMed

In this study, no transgenic gentian (Gentiana triflora x Gentiana scabra) plants produced via Agrobacterium-mediated transformation exhibited transgene (GtMADS, gentian-derived MADS-box genes or sGFP, green fluorescent protein) expression in their leaf tissues, despite the use of constitutive Cauliflower mosaic virus (CaMV) 35S promoter. Strikingly, no expression of the selectable marker gene (bar) used for bialaphos selection was observed. To investigate the possible cause of this drastic transgene silencing, methylation-specific sequences were analysed by bisulfite genomic sequencing using tobacco transformants as a control. Highly methylated cytosine residues of CpG and CpWpG (W contains A or T) sites were distinctively detected in the promoter and 5' coding regions of the transgenes 35S-bar and 35S-GtMADS in all gentian lines analysed. These lines also exhibited various degrees of cytosine methylation in asymmetrical sequences. The methylation frequencies in the other transgene, nopaline synthase (NOS) promoter-driven nptII, and the endogenous GtMADS gene coding region, were much lower and were variable compared with those in the 35S promoter regions. Transgene methylation was observed in the bialaphos-selected transgenic calluses expressing the transgenes, and methylation sequences were distributed preferentially around the as-1 element in the 35S promoter. Calluses derived from leaf tissues of silenced transgenic gentian also exhibited transgene suppression, but expression was recovered by treatment with the methylation inhibitor 5-aza-2'-deoxycytidine (aza-dC). These results indicated that cytosine methylation occurs exclusively in the 35S promoter regions of the expressed transgenes during selection of gentian transformants, causing transcriptional gene silencing. PMID:16262705

Mishiba, Kei-ichiro; Nishihara, Masahiro; Nakatsuka, Takashi; Abe, Yoshiko; Hirano, Hiroshi; Yokoi, Takahide; Kikuchi, Akiko; Yamamura, Saburo

2005-11-01

186

Myocardial T1 mapping: modalities and clinical applications  

PubMed Central

Myocardial fibrosis appears to be linked to myocardial dysfunction in a multitude of non-ischemic cardiomyopathies. Accurate non-invasive quantitation of this extra-cellular matrix has the potential for widespread clinical benefit in both diagnosis and guiding therapeutic intervention. T1 mapping is a cardiac magnetic resonance (CMR) imaging technique, which shows early clinical promise particularly in the setting of diffuse fibrosis. This review will outline the evolution of T1 mapping and the various techniques available with their inherent advantages and limitations. Histological validation of this technique remains somewhat limited, however clinical application in a range of pathologies suggests strong potential for future development. PMID:24834410

Jellis, Christine L.

2014-01-01

187

Transgenic plants expressing HC-Pro show enhanced virus sensitivity while silencing of the transgene results in resistance.  

PubMed

Nicotiana benthamiana plants were engineered to express sequences of the helper component-proteinase (HC-Pro) of Cowpea aphid-borne mosaic potyvirus (CABMV). The sensitivity of the transgenic plants to infection with parental and heterologous viruses was studied. The lines expressing HC-Pro showed enhanced symptoms after infection with the parental CABMV isolate and also after infection with a heterologous potyvirus, Potato virus Y (PVY) and a comovirus, Cowpea mosaic virus (CPMV). On the other hand, transgenic lines expressing nontranslatable HC-Pro or translatable HC-Pro with a deletion of the central domain showed wild type symptoms after infection with the parental CABMV isolate and heterologous viruses. These results showed that CABMV HC-Pro is a pathogenicity determinant that conditions enhanced sensitivity to virus infection in plants, and that the central domain of the protein is essential for this. The severe symptoms in CABMV-infected HC-Pro expressing lines were remarkably followed by brief recovery and subsequent re-establishment of infection, possibly indicating counteracting effects of HC-Pro expression and a host defense response. One of the HC-Pro expressing lines (h48) was found to contain low levels of transgenic HC-Pro RNA and to be resistant to CABMV and to recombinant CPMV expressing HC-Pro. This indicated that h48 was (partially) posttranscriptionally silenced for the HC-Pro transgene inspite of the established role of HC-Pro as a suppressor of posttranscriptional gene silencing. Line h48 was not resistant to PVY, but instead showed enhanced symptoms compared to nontransgenic plants. This may be due to relief of silencing of the HC-Pro transgene by HC-Pro expressed by PVY. PMID:12206307

Mlotshwa, Sizolwenkosi; Verver, Jan; Sithole-Niang, Idah; Prins, Marcel; Van Kammen, A B; Wellink, Joan

2002-01-01

188

Rice transgene flow: its patterns, model and risk management.  

PubMed

Progress has been made in a 12 year's systemic study on the rice transgene flow including (i) with experiments conducted at multiple locations and years using up to 21 pollen recipients, we have elucidated the patterns of transgene flow to different types of rice. The frequency to male sterile lines is 10(1) and 10(3) higher than that to O. rufipogon and rice cultivars. Wind speed and direction are the key meteorological factors affecting rice transgene flow. (ii) A regional applicable rice gene flow model is established and used to predict the maximum threshold distances (MTDs) of gene flow during 30 years in 993 major rice producing counties of southern China. The MTD0.1% for rice cultivars is basically ?5 m in the whole region, despite climate differs significantly at diverse locations and years. This figure is particularly valuable for the commercialization and regulation of transgenic rice. (iii) The long-term fate of transgene integrated into common wild rice was investigated. Results demonstrated that the F1 hybrids of transgenic rice/O. rufipogon gradually disappeared within 3-5 years, and the Bt or bar gene was not detectable in the mixed population, suggesting the O. rufipogon may possess a strong mechanism of exclusiveness for self-protection. (iv) The flowering time isolation and a 2-m-high cloth-screen protection were proved to be effective in reducing transgene flow. We have proposed to use a principle of classification and threshold management for different types of rice. PMID:25431202

Jia, Shirong; Yuan, Qianhua; Pei, Xinwu; Wang, Feng; Hu, Ning; Yao, Kemin; Wang, Zhixing

2014-12-01

189

Engineered Resistance to Plasmodium falciparum Development in Transgenic Anopheles stephensi  

PubMed Central

Transposon-mediated transformation was used to produce Anopheles stephensi that express single-chain antibodies (scFvs) designed to target the human malaria parasite, Plasmodium falciparum. The scFvs, m1C3, m4B7, and m2A10, are derived from mouse monoclonal antibodies that inhibit either ookinete invasion of the midgut or sporozoite invasion of salivary glands. The scFvs that target the parasite surface, m4B7 and m2A10, were fused to an Anopheles gambiae antimicrobial peptide, Cecropin A. Previously-characterized Anopheles cis-acting DNA regulatory elements were included in the transgenes to coordinate scFv production with parasite development. Gene amplification and immunoblot analyses showed promoter-specific increases in transgene expression in blood-fed females. Transgenic mosquito lines expressing each of the scFv genes had significantly lower infection levels than controls when challenged with P. falciparum. PMID:21533066

Jasinskiene, Nijole; Chen, Xiaoguang; Nirmala, Xavier; Marinotti, Osvaldo; Vinetz, Joseph M.; James, Anthony A.

2011-01-01

190

Growth Performance and Gonadal Development of Growth Enhanced Transgenic Tilapia Oreochromis niloticus (L.) Following Heat-Shock-Induced Triploidy  

Microsoft Academic Search

:   Triploid induction offers a way of considerably reducing fertility in fish, and could therefore be employed to help ensure\\u000a that any adverse environmental impact of transgenic fish was markedly less. In order to produce sterile growth-enhanced transgenic\\u000a fish, we have induced triploidy in two lines of transgenic tilapia. Growth performance and gonadal development were analyzed\\u000a following triploidization by heat

Shaharudin Abdul Razak; Gyu-Lin Hwang; M. Azizur Rahman; Norman Maclean

1999-01-01

191

Colored medaka and zebrafish: transgenics with ubiquitous and strong transgene expression driven by the medaka ?-actin promoter.  

PubMed

Conditional cell labeling, cell tracing, and genetic manipulation approaches are becoming increasingly important in developmental and regenerative biology. Such approaches in zebrafish research are hampered by the lack of an ubiquitous transgene driver element that is active at all developmental stages. Here, we report the isolation and characterization of the medaka fish (Oryzias latipes) ?-actin (Olactb) promoter, which drives constitutive transgene expression during all developmental stages, and the analysis of adult organs except blood cell types. Taking advantage of the compact medaka promoter, we succeeded in generating a zebrafish transgenic (Tg) line with unprecedentedly strong and widespread transgene expression from embryonic to adult stages. Moreover, the Tg carries a pair of loxP sites, which enables the reporter fluorophore to switch from DsRed2 to enhanced green fluorescent protein (EGFP). We induced Cre/loxP recombination with Tg(hsp70l: mCherry-t2a-Cre(ERt2) ) in the double Tg embryo and generated a Tg line that constitutively expresses EGFP. We further demonstrate the powerful application of Olactb-driven Tgs for cell lineage tracing using transplantation experiments with embryonic cells at the shield stage and adult cells of regenerating fin. Thus, the use of promoter elements from medaka is an alternative approach to generate Tgs with stronger and even novel expression patterns in zebrafish. The Olactb promoter and the Tg lines presented here represent an important advancement for the broader use of Cre/loxP-based Tg applications in zebrafish. PMID:23157381

Yoshinari, Nozomi; Ando, Kazunori; Kudo, Akira; Kinoshita, Masato; Kawakami, Atsushi

2012-12-01

192

Bioaccessibility of carotenoids from transgenic provitamin A biofortified sorghum.  

PubMed

Biofortified sorghum (Sorghum bicolor (L.) Moench) lines are being developed to target vitamin A deficiency in Sub-Saharan Africa, but the delivery of provitamin A carotenoids from such diverse germplasms has not been evaluated. The purpose of this study was to screen vectors and independent transgenic events for the bioaccessibility of provitamin A carotenoids using an in vitro digestion model. The germplasm background and transgenic sorghum contained 1.0-1.5 and 3.3-14.0 ?g/g ?-carotene equivalents on a dry weight basis (DW), respectively. Test porridges made from milled transgenic sorghum contained up to 250 ?g of ?-carotene equivalents per 100 g of porridge on a fresh weight basis (FW). Micellarization efficiency of all-trans-?-carotene was lower (p < 0.05) from transgenic sorghum (1-5%) than from null/nontransgenic sorghum (6-11%) but not different between vector constructs. Carotenoid bioaccessibility was significantly improved (p < 0.05) by increasing the amount of coformulated lipid in test porridges from 5% w/w to 10% w/w. Transgenic sorghum event Homo188-A contained the greatest bioaccessible ?-carotene content, with a 4-8-fold increase from null/nontransgenic sorghum. While the bioavailability and bioconversion of provitamin A carotenoids from these grains must be confirmed in vivo, these data support the notion that biofortification of sorghum can enhance total and bioaccessible provitamin A carotenoid levels. PMID:23692305

Lipkie, Tristan E; De Moura, Fabiana F; Zhao, Zuo-Yu; Albertsen, Marc C; Che, Ping; Glassman, Kimberly; Ferruzzi, Mario G

2013-06-19

193

Design rules for efficient transgene expression in plants.  

PubMed

Sustained expression of transgenes in specified developmental patterns is commonly needed in plant biotechnology, but obstructed by transgene silencing. Here, we present a set of gene design rules, tested on the silencing-susceptible beetle luc and bacterial ims genes, expressed in sugarcane. Designs tested independently or in combination included removal of rare codons, removal of RNA instability sequences, blocking of likely endogenous sRNA binding sites and randomization of non-rare codons. Stable transgene expression analyses, on multiple independent lines per construct, showed greatest improvement from the removal of RNA instability sequences, accompanied by greatly reduced transcript degradation evident in northern blot analysis. We provide a set of motifs that readily can be eliminated concurrently with rare codons and undesired structural features such as repeat sequences, using Gene Designer 2.0 software. These design rules yielded 935- and 5-fold increased expression in transgenic callus, relative to the native luc and ims sequences; and gave sustained expression under the control of sugarcane and heterologous promoters over several years in greenhouse and field trials. The rules can be applied easily with codon usage tables from any plant species, providing a simple and effective means to achieve sustained expression of otherwise silencing-prone transgenes in plants. PMID:24854834

Jackson, Mark A; Sternes, Peter R; Mudge, Stephen R; Graham, Michael W; Birch, Robert G

2014-09-01

194

Be a Food Detective Grades 9-12: T-1  

E-print Network

Be a Food Detective Grades 9-12: T-1 Be a Food Detective Overview Students will explore the exciting area of food and nutrition and answer specific questions about prepared food products, such as, what a food is made from, the source of its ingredients, and how the ingredients were grown. Suggested

Mathis, Wayne N.

195

Transgene silencing in grapevines transformed with GFLV resistance genes: analysis of variable expression of transgene, siRNAs production and cytosine methylation.  

PubMed

Eight transgenic grapevine lines transformed with the coat protein gene of Grapevine fanleaf virus (GFLV-CP) were analyzed for a correlation between transgene expression, siRNAs production and DNA methylation. Bisulphite genome sequencing was used for a comprehensive analysis of DNA methylation. Methylated cytosine residues of CpG and CpNpG sites were detected in the GFLV-CP transgene, in the T7 terminator and in the 35S promoter of three grapevines without transgene expression, but no detectable level of siRNAs was recorded in these lines. The detailed analysis of 8 lines revealed the complex arrangements of T-DNA and integrated binary vector sequences as crucial factors that influence transgene expression. After inoculation with GFLV, no change in the levels of cytosine methylation was observed, but transgenic and untransformed plants produced short siRNAs (21-22 nt) indicating that the grapevine plants responded to GFLV infection by activating a post-transcriptional gene silencing mechanism. PMID:19507046

Gambino, Giorgio; Perrone, Irene; Carra, Andrea; Chitarra, Walter; Boccacci, Paolo; Torello Marinoni, Daniela; Barberis, Marco; Maghuly, Fatemeh; Laimer, Margit; Gribaudo, Ivana

2010-02-01

196

Alternative silencing effects involve distinct types of non-spreading cytosine methylation at a three-gene, single-copy transgenic locus in rice.  

PubMed

We investigated transgene silencing in a line of rice plants that carries a single-copy 6.6-kb transgenic locus comprising three heterologous transgenes: bar, hpt and gusA. We identified at least three distinct types of silencing effects associated with different methylation patterns, including a novel form of transcriptional silencing involving methylation of cytosine residues only at non-conventional acceptor sites in the coding region. Silencing arose de novo in individual R1, R2 and R3 plants despite the stability of the transgenic locus, although the basic structure of the locus, transgene dosage and position effects remained constant within the line. We found that different silencing effects could occur concurrently in adjacent heterologous transgenes in the same plant, with no evidence for spreading of silenced states or methylation patterns from one transgene to another. PMID:10732679

Fu, X; Kohli, A; Twyman, R M; Christou, P

2000-02-01

197

Transgene- and locus-dependent imprinting reveals allele-specific chromosome conformations.  

PubMed

When positioned into the integrin ?-6 gene, an Hoxd9lacZ reporter transgene displayed parental imprinting in mouse embryos. While the expression from the paternal allele was comparable with patterns seen for the same transgene when present at the neighboring HoxD locus, almost no signal was scored at this integration site when the transgene was inherited from the mother, although the Itga6 locus itself is not imprinted. The transgene exhibited maternal allele-specific DNA hypermethylation acquired during oogenesis, and its expression silencing was reversible on passage through the male germ line. Histone modifications also corresponded to profiles described at known imprinted loci. Chromosome conformation analyses revealed distinct chromatin microarchitectures, with a more compact structure characterizing the maternally inherited repressed allele. Such genetic analyses of well-characterized transgene insertions associated with a de novo-induced parental imprint may help us understand the molecular determinants of imprinting. PMID:23818637

Lonfat, Nicolas; Montavon, Thomas; Jebb, David; Tschopp, Patrick; Nguyen Huynh, Thi Hanh; Zakany, Jozsef; Duboule, Denis

2013-07-16

198

Incipient ferroelectrics: Anomalous T1 behaviors and their rotor interpretation  

NASA Astrophysics Data System (ADS)

The quantum temperature (denoted by T1) behaviors of three typical incipient ferroelectrics, SrTiO 3, KTaO 3 and CaTiO 3, are studied. This quantity is argued to serve fundamentally in identifying the nature of the local mode responsible for the dielectric responses. Our main findings are as follows. For all compounds, T1 saturates at low temperatures. For CaTiO 3, T1 monotonically increases with temperature and no clear saturation is discernible at high temperatures. For KTaO 3, similar behaviors are observed but with a little twist: a dip shows up around 35 K, above which T1 increases but below it T1 decreases with temperature. Although it is hardly seeable in this compound, this dip might mark a transition, whose nature is unclear for the moment. In parallel with KTiO 3, SrTiO 3 also has a dip, which is much stronger and broader. It happens around 105 K, at which the famous anti-ferrodistortive (AFD) transition occurs. Were it not for this dip, T1 would drop to zero in SrTiO 3 at low temperatures and the ferroelectric (FE) transition would take place. The dip halts the drop and makes T1 rise up to a value that is enough to stabilize the FE instability. In this respect, the dip is essential in preventing the FE transition in SrTiO 3. Since the dip and the AFD transition occur at roughly the same temperature, we attempt to ascribe the former to the latter. This ascription is compatible with previous work [A. Yamanaka, M. Kataoka, Y. Inaba, K. Inoue, B. Hehlen, E. Courtens, Europhys. Lett., 50:(2000) 688]. To interpret the T1 behaviors, we utilize an anisotropic rotor model, according to which the local variable is supposed to move on a non-uniform sphere. By tuning the anisotropy parameter, ?, qualitative agreement can be achieved. Especially, a single ??100 can fit the T1 of CaTiO 3 over the entire temperature range under consideration, whereas the fitting for KTaO 3 requires two different ?, namely, ??260 above the dip temperature and ??40 below it. Analogously, two ? are also required for SrTiO 3. Below the dip temperature, a very good fitting can be obtained with ??40. We did not try to fit the high temperature data of SrTiO 3, because the data in this range are scarce and inaccurate. Nevertheless, we believe that a different and bigger ? should be at work, considering the case with KTaO 3. Assuming the AFD transition as the cause of the dip in SrTiO 3, we may claim that, the true role of the AFD transition in stabilizing the FE instability is to reduce the ? and then enhance quantum fluctuations.

Deng, Hai-Yao; Hu, Kaige; Lam, Chi Hang; Huang, Haitao

2012-01-01

199

Transgenic Quail Production by Microinjection of Lentiviral Vector into the Early Embryo Blood Vessels  

PubMed Central

Several strategies have been used to generate transgenic birds. The most successful method so far has been the injection of lentiviral vectors into the subgerminal cavity of a newly laid egg. We report here a new, easy and effective way to produce transgenic quails through direct injection of a lentiviral vector, containing an enhanced-green fluorescent protein (eGFP) transgene, into the blood vessels of quail embryos at Hamburger-Hamilton stage 13–15 (HH13–15). A total of 80 embryos were injected and 48 G0 chimeras (60%) were hatched. Most injected embryo organs and tissues of hatched quails were positive for eGFP. In five out of 21 mature G0 male quails, the semen was eGFP-positive, as detected by polymerase chain reaction (PCR), indicating transgenic germ line chimeras. Testcross and genetic analyses revealed that the G0 quail produced transgenic G1 offspring; of 46 G1 hatchlings, 6 were transgenic (6/46, 13.0%). We also compared this new method with the conventional transgenesis using stage X subgerminal cavity injection. Total 240 quail embryos were injected by subgerminal cavity injection, of which 34 (14.1%) were hatched, significantly lower than the new method. From these hatched quails semen samples were collected from 19 sexually matured males and tested for the transgene by PCR. The transgene was present in three G0 male quails and only 4/236 G1 offspring (1.7%) were transgenic. In conclusion, we developed a novel bird transgenic method by injection of lentiviral vector into embryonic blood vessel at HH 13–15 stage, which result in significant higher transgenic efficiency than the conventional subgerminal cavity injection. PMID:23251391

Zhang, Zifu; Sun, Peng; Yu, Fuxian; Yan, Li; Yuan, Fang; Zhang, Wenxin; Wang, Tao; Wan, Zhiyi; Shao, Qiang; Li, Zandong

2012-01-01

200

Experiments in Transgenic Mice Show That Hepatocytes Are the Source for Postnatal Liver Growth and Do Not Stream  

E-print Network

Experiments in Transgenic Mice Show That Hepatocytes Are the Source for Postnatal Liver Growth'2 One hypothesis is that postnatal liver growth involves replication of mature hepatocytes, which have% of hepatocytes in two dif- ferent transgenic lines stain blue with X-gal. In neonatal animals, singlets

Ponder, Katherine P.

201

Resistance of ?AI-1 transgenic chickpea (Cicer arietinum) and cowpea (Vigna unguiculata) dry grains to bruchid beetles (Coleoptera: Chrysomelidae).  

PubMed

Dry grain legume seeds possessing ?AI-1, an ?-amylase inhibitor from common bean (Phaseolus vulgaris), under the control of a cotyledon-specific promoter have been shown to be highly resistant to several important bruchid pest species. One transgenic chickpea and four cowpea lines expressing ?AI-1, their respective controls, as well as nine conventional chickpea cultivars were assessed for their resistance to the bruchids Acanthoscelides obtectus (Say), Callosobruchus chinensis L. and Callosobruchus maculatus F. All transgenic lines were highly resistant to both Callosobruchus species. A. obtectus, known to be tolerant to ?AI-1, was able to develop in all transgenic lines. While the cotyledons of all non-transgenic cultivars were highly susceptible to all bruchids, C. chinensis and C. maculatus larvae suffered from significantly increased mortality rates inside transgenic seeds. The main factor responsible for the partial resistance in the non-transgenic cultivars was deduced to reside in the seed coat. The ?AI-1 present in seeds of transgenic chickpea and cowpea lines significantly increases their resistance to two important bruchid pest species (C. chinensis and C. maculatus) essentially to immunity. To control ?AI-1 tolerant bruchid species such as A. obtectus and to avoid the development of resistance to ?AI-1, varieties carrying this transgene should be protected with additional control measures. PMID:23458831

Lüthi, Christoph; Alvarez-Alfageme, Fernando; Ehlers, Jeffrey D; Higgins, Thomas J V; Romeis, Jörg

2013-08-01

202

Assessment of fitness components in transgenic Japanese medaka as a model to assess environmental risk in genetically modified organisms  

Microsoft Academic Search

The objective of this research was to establish methods to estimate the fitness components needed to predict the potential for transgenic organisms to spread in a wild population. Three transgenic (TR) lines of Japanese medaka (Oryzias latipes) were used, one microinjected with a human growth hormone gene construct (hGH) and two injected with a salmon growth hormone gene construct (400

Liza V Jimenez

2000-01-01

203

26 CFR 31.3402(t)-1 - Withholding requirement on certain payments made by government entities.  

Code of Federal Regulations, 2012 CFR

...payments made by government entities. 31.3402(t)-1 Section 31.3402(t)-1 Internal Revenue INTERNAL REVENUE SERVICE... Collection of Income Tax at Source § 31.3402(t)-1 Withholding requirement on certain...

2012-04-01

204

ACTS T1-VSAT - The intelligent earth station  

NASA Astrophysics Data System (ADS)

The functional design of the software for NASA's Advanced Communication Technology Satellite (ACTS) T1-VSAT (Very Small Aperture Terminal) is described. The design provides a flexible interface to allow customized control of a satellite network and to provide external processes with access to network capabilities without requiring modification to the network hardware or software. Some of the envisioned features are: automatic number location; dynamic reconfiguration of the number plan tables; security features of call priority, call preemption, and remote verification; automatic reconfiguration of least cost routing tables; circuit availability verification prior to call setup; audio and video conferencing; on demand broadband dial-up service; on demand dial-up broadband broadcast service; and ISDN. A brief review is also given of the ACTS satellite and network, the network management, and the ACTS T1-VSAT earth station.

Manning, John R.; Spiegler, Jeffrey D.; Lowry, Peter A.

1992-03-01

205

Recent Results of IRAN-T1 Tokamak  

SciTech Connect

In this article after introducing the IR-T1 tokamak and its diagnostic systems a brief discussion on the range of grossly stable operating conditions of its plasma by Hugill diagram is presented. Hard disruption instability is studied experimentally in the next part, which confirms that MHD behavior in small tokamaks can be characterized by a single parameter q(a), safety factor at plasma edge. Finally the characteristics of the new regime of IR-T1 are reported. By our new model of triggering different fields (toroidal, ohmic and vertical), the plasma duration time is increased up to 35 ms with Ip of about 25 kA. By modifying capacitance and charging voltage of ohmic and vertical fields the spike oscillations which was appeared in the plasma behavior is taken out. The role of cleaning the vacuum chamber and using heavier gas for glow discharge and the effect of base pressure is described in detail.

Dorranian, D.; Ghoranneviss, M.; Salem, M. K.; Mahmoodi D, M.; Arvin, R.; Talebitaher, Alireza; Abhari, Ali [Plasma Physics Research Center, Science and Research Campus, Islamic Azad University, Poonak, Hesarak, Tehran (14736) (Iran, Islamic Republic of); Khorshid, P. [Physics Dept., Mashhad Campus, Islamic Azad University, Mashhad (Iran, Islamic Republic of); Hojabri, A. [Physics Dept., Karaj Campus, Islamic Azad University, Karaj (Iran, Islamic Republic of)

2006-12-04

206

J=0 T=1 Pairing Interaction Selection Rules  

E-print Network

Wave functions arising form a pairing Hamiltonian E(0) i,e, one in which the interaction is only between J=0^{+}T=1 pairs, lead to magnetic dipole and Gamow-Teller transition rates that are much larger than those from an interaction E(J_{max}) in which a proton and a neutron couple to J=2j. With realistic interactions the results are in between the 2 extremes. In the course of this study we found that certain M1 and GT matrix elements vanish with E(0) . These are connected to seniority and reduced isospin isospin selection rules. We find the surprising result that The M1 strength to the single j scissors is larger for a J=0 T=1 pairing interaction than it is for Q.Q.

Matthew Harper; Larry Zamick

2014-08-18

207

Transgenic mouse model of malignant skin melanoma.  

PubMed Central

Tyr-SV40E transgenic mice are specifically susceptible to melanoma due to expression of the oncogene in pigment cells. Mice of the more susceptible lines die young of early-onset eye melanomas, when skin melanomas are still infrequent and benign. To surmount this obstacle, skin from donors of two high-susceptibility lines was grafted to Tyr-SV40E hosts of a low-susceptibility line of the same inbred strain, thereby enabling the skin to outlive the donors and continue to grow in immunocompetent but tolerant hosts. Unexpectedly, donor pigment cells in all the grafts soon selectively proliferated close to areas of greatest wound healing, forming a dense black tracery, especially at the outer rim of the grafts. These lesions slowly grew radially within the grafts, producing irregular greyish patches. Local vertical thickenings then appeared and developed into small melanomas, which soon ulcerated through the epidermis. The tumors rapidly enlarged and became deeply invasive. Discrete black nevi also arose, with many becoming larger and distinctly blue, but those not near areas of pronounced wound healing did not progress to malignancy. In this first series, malignant melanoma resulted in all the grafts from the more susceptible of two donor lines and in some grafts from the other line. Distant metastases occurred in some cases from each line. Most tumors were hypomelanotic and heterogeneous, with lobes or areas differing in melanization. The results strongly suggest that growth factors and cytokines--known to be produced in wound repair--are triggering the growth and malignant conversion of these genetically susceptible melanocytes and that in the graft situation we are merely witnessing a caricature--a usefully exaggerated manifestation of the true events underlying the genesis of melanomas. The striking resemblance to the human malignancy, the genetic uniformity and different susceptibilities of the transgenic lines, and the experimental possibilities in the grafted mice all make them an excellent model of the disease. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 PMID:8415613

Mintz, B; Silvers, W K

1993-01-01

208

Cellular lipid accumulation by Pseudomonas aeruginosa 44T1  

Microsoft Academic Search

Growth of Pseudomonas aeruginosa strain 44T1 on glucose, an n-alkane mixture or olive oil was characterized by the formation of intracellular lipid inclusions and extracellular accumulation of rhamnolipids. Maximum values of cellular lipid accumulation were obtained in olive-oil-grown cells and reached up to 38% w\\/w of its dry biomass. The principal fatty acids of cellular lipids drived from P. aeruginosa

C. de AndrOs; M. J. Espuny; M. Robert; M. E. Mercadé; A. Manresa; J. Guinea

1991-01-01

209

The Construction and Expression of Lysine-Rich Gene in the Mammary Gland of Transgenic Mice  

PubMed Central

Lysine is the limiting amino acid in cereal grains, which represent a major source of human food and animal feed worldwide, and is considered the most important of the essential amino acids. In this study, ?-casein, ?S2-casein, and lactotransferrin cDNA clone fragments encoding lysine-rich peptides were fused together to generate a lysine-rich (LR) gene and the mammary gland-specific expression vector pBC1-LR-NEOr was constructed. Transgenic mice were generated by pronuclear microinjection of the linearized expression vectors harboring the LR transgene. The transgenic mice and their offspring were examined using multiplex polymerase chain reaction (PCR), Southern blotting, reverse transcriptase–PCR, in situ hybridization, and Western blotting techniques. Our results showed that the LR gene was successfully integrated into the mouse genome and was transmitted stably. The specific LR gene expression was restricted to the mammary gland, active alveoli of the transgenic female mice during lactation. The lysine level of the two transgenic lines was significantly higher than that of nontransgenic controls (p<0.05). In addition, the growth performance of transgenic pups was enhanced by directly feeding them the LR protein-enriched transgenic milk. Our results demonstrated that lysine-rich gene was successfully constructed and expressed in mammary gland of transgenic mice. This study will provide a better understanding of how mammary gland expression systems that increase the lysine content of milk can be applied to other mammals, such as cows. PMID:22577831

Ma, Xin; Zhang, Peng; Song, Guangqi; Chen, Yue; Wang, Zhongwei; Yin, Yupeng; Kong, Delong; Zhang, Sheng; Zhao, Zhihui; Ouyang, Hongsheng

2012-01-01

210

Epstein-Barr virus nuclear antigen 1 does not induce lymphoma in transgenic FVB mice  

PubMed Central

The lymphoma-inducing potential of Ig heavy-chain enhancer- and promoter-regulated Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) was evaluated in three transgenic FVB mouse lineages. EBNA1 was expressed at a higher level in transgenic B220(+) splenocytes than in EBV-infected lymphoblastoid cell lines. EBNA1 was also expressed in B220(-) transgenic splenocytes and thymocytes. Before killing and assessments at 18-26 months, EBNA1-transgenic mice did not differ from control mice in mortality. At 18-26 months EBNA1-transgenic mice did not differ from littermate control in ultimate body weight, in spleen size or weight, in lymph node, kidney, liver, or spleen histology, in splenocyte fractions positive for cluster of differentiation (CD)3?, CD4, CD8, CD62L, B220, CD5, IgM, IgD, MHC class II, CD11b, or CD25, or in serum IgM, IgG, or total Ig levels. Lymphomas were not found in spleens or other organs of 18- to 26-month-old EBNA1-transgenic (n = 86) or control (n = 45) FVB mice. EBNA1-transgenic lineages had a higher pulmonary adenoma prevalence than did littermate controls (39% versus 7%). However, the adenoma prevalence was not higher in EBNA1-transgenic mice than has been described for FVB mice, and EBNA1 was not expressed in normal pulmonary epithelia or adenomas. PMID:15640350

Kang, Myung-Soo; Lu, Hongxiang; Yasui, Teruhito; Sharpe, Arlene; Warren, Henry; Cahir-McFarland, Ellen; Bronson, Roderick; Hung, Siu Chun; Kieff, Elliott

2005-01-01

211

[Biofuels, food security and transgenic crops].  

PubMed

Soaring global food prices are threatening to push more poor people back below the poverty line; this will probably become aggravated by the serious challenge that increasing population and climate changes are posing for food security. There is growing evidence that human activities involving fossil fuel consumption and land use are contributing to greenhouse gas emissions and consequently changing the climate worldwide. The finite nature of fossil fuel reserves is causing concern about energy security and there is a growing interest in the use of renewable energy sources such as biofuels. There is growing concern regarding the fact that biofuels are currently produced from food crops, thereby leading to an undesirable competition for their use as food and feed. Nevertheless, biofuels can be produced from other feedstocks such as lingo-cellulose from perennial grasses, forestry and vegetable waste. Biofuel energy content should not be exceeded by that of the fossil fuel invested in its production to ensure that it is energetically sustainable; however, biofuels must also be economically competitive and environmentally acceptable. Climate change and biofuels are challenging FAO efforts aimed at eradicating hunger worldwide by the next decade. Given that current crops used in biofuel production have not been domesticated for this purpose, transgenic technology can offer an enormous contribution towards improving biofuel crops' environmental and economic performance. The present paper critically presents some relevant relationships between biofuels, food security and transgenic plant technology. PMID:19722000

Acosta, Orlando; Chaparro-Giraldo, Alejandro

2009-01-01

212

Progressive 35S promoter methylation increases rapidly during vegetative development in transgenic Nicotiana attenuata plants  

PubMed Central

Background Genetically modified plants are widely used in agriculture and increasingly in ecological research to enable the selective manipulation of plant traits in the field. Despite their broad usage, many aspects of unwanted transgene silencing throughout plant development are still poorly understood. A transgene can be epigenetically silenced by a process called RNA directed DNA methylation (RdDM), which can be seen as a heritable loss of gene expression. The spontaneous nature of transgene silencing has been widely reported, but patterns of acquirement remain still unclear. Results Transgenic wild tobacco plants (Nicotiana attenuata) expressing heterologous genes coding for antimicrobial peptides displayed an erratic and variable occurrence of transgene silencing. We focused on three independently transformed lines (PNA 1.2, PNA 10.1 and ICE 4.4) as they rapidly lost the expression of the resistance marker and down-regulated transgene expression by more than 200 fold after only one plant generation. Bisulfite sequencing indicated hypermethylation within the 35S and NOS promoters of these lines. To shed light on the progress of methylation establishment, we successively sampled leaf tissues from different stages during plant development and found a rapid increase in 35S promoter methylation during vegetative growth (up to 77% absolute increase within 45 days of growth). The levels of de novo methylation were inherited by the offspring without any visible discontinuation. A secondary callus regeneration step could interfere with the establishment of gene silencing and we found successfully restored transgene expression in the offspring of several regenerants. Conclusions The unpredictability of the gene silencing process requires a thorough selection and early detection of unstable plant lines. De novo methylation of the transgenes was acquired solely during vegetative development and did not require a generational change for its establishment or enhancement. A secondary callus regeneration step provides a convenient way to rescue transgene expression without causing undesirable morphological effects, which is essential for experiments that use transformed plants in the analysis of ecologically important traits. PMID:23837904

2013-01-01

213

Expression of human growth hormone in the milk of transgenic rabbits with transgene mapped to the telomere region of chromosome 7q.  

PubMed

The advent of transgenic technology has provided methods for the production of pharmaceuticals by the isolation of these proteins from transgenic animals. The mammary gland has been focused on as a bioreactor, since milk is easily collected from lactating animals and protein production can be expressed at very high levels, including hormones and enzymes. We demonstrate here the expression pattern of recombinant human growth hormone (rhGH) in transgenic rabbits carrying hGH genomic sequences driven by the rat whey acidic protein (WAP) promoter. The transgene was mapped to the q26-27 telomere region of chromosome 7q by fluorescence in situ hybridization (FISH). Nearly 30 % of the F1 generation demonstrated the presence of transgene. The recombinant growth hormone was detected in the milk of the transgenic rabbit females, but not in serum, up to the level of 10 ?g/ml. Ectopic expression of the transgene in the brain, heart, kidney, liver, and salivary gland was not observed, indicating that a short sequence of rat WAP promoter (969 bp) contained essential sequences directing expression exclusively to the mammary gland. The biological activity of recombinant growth hormone was measured by immunoreactivity and the capability to stimulate growth of the hormone-dependent Nb211 cell line. PMID:22898896

Lipinski, Daniel; Zeyland, Joanna; Szalata, Marlena; Plawski, Andrzej; Jarmuz, Malgorzata; Jura, Jacek; Korcz, Aleksandra; Smorag, Zdzislaw; Pienkowski, Marek; Slomski, Ryszard

2012-11-01

214

Transgenic RNA Interference in Mice  

NSDL National Science Digital Library

The discovery that small interfering RNA duplexes (siRNA) can silence gene expression in mammalian cells has revolutionized biomedical research. The most successful application of the discovery has been to study gene function in cultured human or mouse cells. However, the knockdown effect of siRNA is only transient. To achieve a more sustained gene-silencing effect, shRNA (small hairpin RNA) expressed from a vector is preferred. An additional benefit of shRNA is that RNA interference (RNAi) can now be applied in vivo through delivering shRNA-expressing vectors by transgenic technology. Transgenic RNAi not only allows the study of biological processes not present in cultured cells but also offers chronic therapeutic potentials. In this review, we will summarize the developments in the generation of transgenic RNAi mice.

2007-06-01

215

Comprehensive assessment of milk composition in transgenic cloned cattle.  

PubMed

The development of transgenic cloned animals offers new opportunities for agriculture, biomedicine and environmental science. Expressing recombinant proteins in dairy animals to alter their milk composition is considered beneficial for human health. However, relatively little is known about the expression profile of the proteins in milk derived from transgenic cloned animals. In this study, we compared the proteome and nutrient composition of the colostrum and mature milk from three lines of transgenic cloned (TC) cattle that specifically express human ?-lactalbumin (TC-LA), lactoferrin (TC-LF) or lysozyme (TC-LZ) in the mammary gland with those from cloned non-transgenic (C) and conventionally bred normal animals (N). Protein expression profile identification was performed, 37 proteins were specifically expressed in the TC animals and 70 protein spots that were classified as 22 proteins with significantly altered expression levels in the TC and C groups compared to N group. Assessment of the relationship of the transgene effect and normal variability in the milk protein profiles in each group indicated that the variation in the endogenous protein profiles of the three TC groups was within the limit of natural variability. More than 50 parameters for the colostrum and mature milk were compared between each TC group and the N controls. The data revealed essentially similar profiles for all groups. This comprehensive study demonstrated that in TC cattle the mean values for the measured milk parameters were all within the normal range, suggesting that the expression of a transgene does not affect the composition of milk. PMID:23185411

Zhang, Ran; Guo, Chengdong; Sui, Shunchao; Yu, Tian; Wang, Jianwu; Li, Ning

2012-01-01

216

Amino Acids Regulate Transgene Expression in MDCK Cells  

PubMed Central

Gene expression and cell growth rely on the intracellular concentration of amino acids, which in metazoans depends on extracellular amino acid availability and transmembrane transport. To investigate the impact of extracellular amino acid concentrations on the expression of a concentrative amino acid transporter, we overexpressed the main kidney proximal tubule luminal neutral amino acid transporter B0AT1-collectrin (SLC6A19-TMEM27) in MDCK cell epithelia. Exogenously expressed proteins co-localized at the luminal membrane and mediated neutral amino acid uptake. However, the transgenes were lost over few cell culture passages. In contrast, the expression of a control transgene remained stable. To test whether this loss was due to inappropriately high amino acid uptake, freshly transduced MDCK cell lines were cultivated either with physiological amounts of amino acids or with the high concentration found in standard cell culture media. Expression of exogenous transporters was unaffected by physiological amino acid concentration in the media. Interestingly, mycoplasma infection resulted in a significant increase in transgene expression and correlated with the rapid metabolism of L-arginine. However, L-arginine metabolites were shown to play no role in transgene expression. In contrast, activation of the GCN2 pathway revealed by an increase in eIF2? phosphorylation may trigger transgene derepression. Taken together, high extracellular amino acid concentration provided by cell culture media appears to inhibit the constitutive expression of concentrative amino acid transporters whereas L-arginine depletion by mycoplasma induces the expression of transgenes possibly via stimulation of the GCN2 pathway. PMID:24797296

Torrente, Marta; Guetg, Adriano; Sass, Jorn Oliver; Arps, Lisa; Ruckstuhl, Lisa; Camargo, Simone M. R.; Verrey, Francois

2014-01-01

217

How To Produce and Characterize Transgenic Plants.  

ERIC Educational Resources Information Center

Explains the process of establishing transgenic plants which is a very important tool in plant biology and modern agriculture. Produces transgenic plants with the ability to synthesize opines. (Contains 17 references.) (YDS)

Savka, Michael A.; Wang, Shu-Yi; Wilson, Mark

2002-01-01

218

Transgene stability and dispersal in forest trees  

Microsoft Academic Search

Transgenics from several forest tree species, carrying a number of commercially important recombinant genes, have been produced,\\u000a and are undergoing confined field trials in a number of countries. However, there are questions and issues regarding stability\\u000a of transgene expression and transgene dispersal that need to be addressed in long-lived forest trees. Variation in transgene\\u000a expression is not uncommon in the

Mulkh Raj Ahuja

2009-01-01

219

Transgenic Fish as Models in Environmental Toxicology  

Microsoft Academic Search

Historically, fish have played significant roles in assessing potential risks associated with exposure to chemical con- tamination in aquatic environments. Considering the contri- butions of transgenic rodent models to biomedicine, it is reasoned that the development of transgenic fish could enhance the role of fish in environmental toxicology. Application of transgenic fish in environmental studies remains at an early stage,

Richard N. Winn

220

Expression of Recombinant Human Alpha-Lactalbumin in the Milk of Transgenic Goats Using a Hybrid Pomoter/Enhancer  

PubMed Central

To improve nutrient content of goat milk, we describe the construction of a vector (pBLAC) containing a hybrid goat ?-lactoglobulin (BLG) promoter/cytomegalovirus (CMV) enhancer. We also describe the generation of transgenic goats expressing rhLA by somatic cell nuclear transfer (SCNT). Of 334 one-cell stage embryos derived from three transgenic cell lines and 99 embryos derived from non-transgenic (NT) cells surgically transferred to the oviducts of 37 recipients, two recipients delivered two kids (2%) from the non-transfected line and five recipients delivered six kids (1.8%) from transgenic cell lines, three of which died within 2 days. Compared to the NT donor cells, transfection of donor cells does not negatively affect the development of nuclear transfer embryos into viable transgenic offspring. However, the clone efficiency in cell line number 1 was lower than that in numbers 2 and 3, and in the NT lines (0.9% versus 1.9% 2.4% and 2%; P < 0.05). Two transgenic cloned goats expressed rhLA in the milk at 0.1–0.9?mg/mL. The mammary gland-specific expression vector pBLAC with hybrid BLG/CMV can drive the hLA gene to express in vitro and in vivo. These data establish the basis for use of a hybrid promoter/enhancer strategy to produce rhLA transgenic goats. PMID:24527256

Yuan, Yu-Guo; An, Liyou; Yu, Baoli; Song, Shaozheng; Zhou, Feng; Zhang, Liqing; Gu, Yinyin; Yu, Minghui; Cheng, Yong

2014-01-01

221

Expression of recombinant human alpha-lactalbumin in the milk of transgenic goats using a hybrid pomoter/enhancer.  

PubMed

To improve nutrient content of goat milk, we describe the construction of a vector (pBLAC) containing a hybrid goat ? -lactoglobulin (BLG) promoter/cytomegalovirus (CMV) enhancer. We also describe the generation of transgenic goats expressing rhLA by somatic cell nuclear transfer (SCNT). Of 334 one-cell stage embryos derived from three transgenic cell lines and 99 embryos derived from non-transgenic (NT) cells surgically transferred to the oviducts of 37 recipients, two recipients delivered two kids (2%) from the non-transfected line and five recipients delivered six kids (1.8%) from transgenic cell lines, three of which died within 2 days. Compared to the NT donor cells, transfection of donor cells does not negatively affect the development of nuclear transfer embryos into viable transgenic offspring. However, the clone efficiency in cell line number 1 was lower than that in numbers 2 and 3, and in the NT lines (0.9% versus 1.9% 2.4% and 2%; P < 0.05). Two transgenic cloned goats expressed rhLA in the milk at 0.1-0.9?mg/mL. The mammary gland-specific expression vector pBLAC with hybrid BLG/CMV can drive the hLA gene to express in vitro and in vivo. These data establish the basis for use of a hybrid promoter/enhancer strategy to produce rhLA transgenic goats. PMID:24527256

Yuan, Yu-Guo; An, Liyou; Yu, Baoli; Song, Shaozheng; Zhou, Feng; Zhang, Liqing; Gu, Yinyin; Yu, Minghui; Cheng, Yong

2014-01-01

222

Productive Measles Virus Brain Infection and Apoptosis in CD46 Transgenic Mice  

Microsoft Academic Search

Measles virus (MV) infection causes acute childhood disease, associated in certain cases with infection of the central nervous system (CNS) and development of neurological disease. To develop a murine model of MV-induced pathology, we generated several lines of transgenic mice ubiquitously expressing as the MV receptor a human CD46 molecule with either a Cyt1 or Cyt2 cytoplasmic tail. All transgenic

ALEXEY EVLASHEV; EMMANUEL MOYSE; HELENE VALENTIN; OLGA AZOCAR; MARIE-CLAUDE TRESCOL-BIEMONT; JULIEN C. MARIE; C. Rabourdin-Combe; B. Horvat

2000-01-01

223

Molecular cloning and functional characterization of a human VIP receptor from SUP-T1 lymphoblasts.  

PubMed

We have cloned and sequenced a cDNA isolated from a human SUP-T1 lymphoblast cell line library. It encoded a 457 amino acids protein having 87% identity with the rat PACAP type II, VIP2 receptor. Chinese hamster ovary (CHO) cells stably transfected with cloned cDNA expressed a specific binding of 125I[Acetyl-His1]PACAP-27. This binding was inhibited by GTP, and by the peptides helodermin, VIP, PACAP-27 and PACAP-38 that also stimulated adenylate cyclase activity. The order of potency was PACAP-38 > VIP > or = helodermin > or = PACAP-27. Comparison of the results in two cell lines expressing different receptor densities suggested that helodermin and PACAP-38 had a higher intrinsic activity than VIP and PACAP-27. PMID:7811244

Svoboda, M; Tastenoy, M; Van Rampelbergh, J; Goossens, J F; De Neef, P; Waelbroeck, M; Robberecht, P

1994-12-30

224

Exercise and type 1 diabetes (T1DM).  

PubMed

Physical exercise is firmly incorporated in the management of type 1 diabetes (T1DM), due to multiple recognized beneficial health effects (cardiovascular disease prevention being preeminent). When glycemic values are not excessively low or high at the time of exercise, few absolute contraindications exist; practical guidelines regarding amount, type, and duration of age-appropriate exercise are regularly updated by entities such as the American Diabetes Association and the International Society for Pediatric and Adolescent Diabetes. Practical implementation of exercise regimens, however, may at times be problematic. In the poorly controlled patient, specific structural changes may occur within skeletal muscle fiber, which is considered by some to be a disease-specific myopathy. Further, even in well-controlled patients, several homeostatic mechanisms regulating carbohydrate metabolism often become impaired, causing hypo- or hyperglycemia during and/or after exercise. Some altered responses may be related to inappropriate exogenous insulin administration, but are often also partly caused by the "metabolic memory" of prior glycemic events. In this context, prior hyperglycemia correlates with increased inflammatory and oxidative stress responses, possibly modulating key exercise-associated cardio-protective pathways. Similarly, prior hypoglycemia correlates with impaired glucose counterregulation, resulting in greater likelihood of further hypoglycemia to develop. Additional exercise responses that may be altered in T1DM include growth factor release, which may be especially important in children and adolescents. These multiple alterations in the exercise response should not discourage physical activity in patients with T1DM, but rather should stimulate the quest for the identification of the exercise formats that maximize beneficial health effects. PMID:23897688

Galassetti, Pietro; Riddell, Michael C

2013-07-01

225

Paradoxical Locomotor Behavior of Dopamine D1 Receptor Transgenic Mice  

Microsoft Academic Search

The behavioral effects of augmenting dopamine D1 receptor expression in the brain were investigated in mice incorporating additional copies of the mouse D1 receptor gene. Two transgenic lines showed increases in brain D1 receptor binding sites, which were greatest in extrastriatal regions. The full D1 agonist SKF 81297, when administered systemically to control animals, stimulated a dose-dependent increase in locomotor

Stella Dracheva; Ming Xu; Kevin A. Kelley; Vahram Haroutunian; Gay R. Holstein; Shannan Haun; Jeffrey H. Silverstein; Stuart C. Sealfon

1999-01-01

226

Promoter analysis of a growth hormone transgene in Atlantic salmon.  

PubMed

The ocean pout (Macrozoarces americanus) op5a antifreeze protein gene promoter has been used to generate a line of growth hormone (GH) transgenic Atlantic salmon with greatly enhanced growth rates. A study of the genomically integrated GH transgene (EO-1 alpha) in this line of salmon revealed that the first 1579 bp of the 2115-bp promoter was deleted and relocated downstream of the GH coding region, raising questions regarding the ability of the truncated promoter to drive expression of the GH transgene and the potential influence of the relocated 5' promoter region. In this study, 11 promoter constructs were fused to a luciferase reporter gene, and their transcriptional ability was examined after transfection into salmon and human cell lines cultured at 21 and 37 degrees C, respectively. Construct expression was similar in all cell lines, apart from those of less than 266 bp, where expression in the salmon cells greatly exceeded that of the human cells. The results demonstrated the presence of positive and negative regulatory regions within the promoter that would allow the regulation of gene expression at multiple sites. Removal of the first 1579 bp from the promoter resulted in a 70% loss of the luciferase expression exhibited by the full-length promoter, whereas ligating the deleted 5' promoter sequence downstream of the luciferase reporter gene only restored approximately 10% of this loss. These results suggested that in vivo expression of the EO-1 alpha transgene is driven by elements within the weak truncated promoter in conjunction with the relocated 5' promoter region. PMID:19324402

Butler, T M; Fletcher, G L

2009-07-01

227

Transit timing analysis of CoRoT-1b  

Microsoft Academic Search

CoRoT, the pioneer space-based transit search, steadily provides thousands of\\u000ahigh-precision light curves with continuous time sampling over periods of up to\\u000a5 months. The transits of a planet perturbed by an additional object are not\\u000astrictly periodic. By studying the transit timing variations (TTVs), additional\\u000aobjects can be detected in the system.\\u000a A transit timing analysis of CoRoT-1b is

Sz. Csizmadia; S. Renner; P. Barge; E. Agol; S. Aigrain; R. Alonso; J. M. Almenara; A. S. Bonomo; P. Borde; F. Bouchy; J. Cabrera; H. J. Deeg; R. De la Reza; M. Deleuil; R. Dvorak; A. Erikson; E. W. Guenther; M. Fridlund; P. Gondoin; T. Guillot; A. Hatzes; L. Jorda; H. Lammer; C. Lázaro; A. Llebaria; P. Magain; C. Moutou; M. Ollivier; M. Paetzold; D. Queloz; H. Rauer; D. Rouan; J. Schneider; G. Wuchterl; D. Gandolfi

2009-01-01

228

Transgenic Manipulation of the Metabolism of Polyamines in Poplar Cells1  

PubMed Central

The metabolism of polyamines (putrescine, spermidine, and spermine) has become the target of genetic manipulation because of their significance in plant development and possibly stress tolerance. We studied the polyamine metabolism in non-transgenic (NT) and transgenic cells of poplar (Populus nigra × maximowiczii) expressing a mouse Orn decarboxylase (odc) cDNA. The transgenic cells showed elevated levels of mouse ODC enzyme activity, severalfold higher amounts of putrescine, a small increase in spermidine, and a small reduction in spermine as compared with NT cells. The conversion of labeled ornithine (Orn) into putrescine was significantly higher in the transgenic than the NT cells. Whereas exogenously supplied Orn caused an increase in cellular putrescine in both cell lines, arginine at high concentrations was inhibitory to putrescine accumulation. The addition of urea and glutamine had no effect on polyamines in either of the cell lines. Inhibition of glutamine synthetase by methionine sulfoximine led to a substantial reduction in putrescine and spermidine in both cell lines. The results show that: (a) Transgenic expression of a heterologous odc gene can be used to modulate putrescine metabolism in plant cells, (b) accumulation of putrescine in high amounts does not affect the native arginine decarboxylase activity, (c) Orn biosynthesis occurs primarily from glutamine/glutamate and not from catabolic breakdown of arginine, (d) Orn biosynthesis may become a limiting factor for putrescine production in the odc transgenic cells, and (e) assimilation of nitrogen into glutamine keeps pace with an increased demand for its use for putrescine production. PMID:11299393

Bhatnagar, Pratiksha; Glasheen, Bernadette M.; Bains, Suneet K.; Long, Stephanie L.; Minocha, Rakesh; Walter, Christian; Minocha, Subhash C.

2001-01-01

229

Brain selective transgene expression in zebrafish using an NRSE derived motif  

PubMed Central

Transgenic technologies enable the manipulation and observation of circuits controlling behavior by permitting expression of genetically encoded reporter genes in neurons. Frequently though, neuronal expression is accompanied by transgene expression in non-neuronal tissues, which may preclude key experimental manipulations, including assessment of the contribution of neurons to behavior by ablation. To better restrict transgene expression to the nervous system in zebrafish larvae, we have used DNA sequences derived from the neuron-restrictive silencing element (NRSE). We find that one such sequence, REx2, when used in conjunction with several basal promoters, robustly suppresses transgene expression in non-neuronal tissues. Both in transient transgenic experiments and in stable enhancer trap lines, suppression is achieved without compromising expression within the nervous system. Furthermore, in REx2 enhancer trap lines non-neuronal expression can be de-repressed by knocking down expression of the NRSE binding protein RE1-silencing transcription factor (Rest). In one line, we show that the resulting pattern of reporter gene expression coincides with that of the adjacent endogenous gene, hapln3. We demonstrate that three common basal promoters are susceptible to the effects of the REx2 element, suggesting that this method may be useful for confining expression from many other promoters to the nervous system. This technique enables neural specific targeting of reporter genes and thus will facilitate the use of transgenic methods to manipulate circuit function in freely behaving larvae. PMID:23293587

Bergeron, Sadie A.; Hannan, Markus C.; Codore, Hiba; Fero, Kandice; Li, Grace H.; Moak, Zachary; Yokogawa, Tohei; Burgess, Harold A.

2012-01-01

230

ZFIN, the Zebrafish Model Organism Database: increased support for mutants and transgenics  

PubMed Central

ZFIN, the Zebrafish Model Organism Database (http://zfin.org), is the central resource for zebrafish genetic, genomic, phenotypic and developmental data. ZFIN curators manually curate and integrate comprehensive data involving zebrafish genes, mutants, transgenics, phenotypes, genotypes, gene expressions, morpholinos, antibodies, anatomical structures and publications. Integrated views of these data, as well as data gathered through collaborations and data exchanges, are provided through a wide selection of web-based search forms. Among the vertebrate model organisms, zebrafish are uniquely well suited for rapid and targeted generation of mutant lines. The recent rapid production of mutants and transgenic zebrafish is making management of data associated with these resources particularly important to the research community. Here, we describe recent enhancements to ZFIN aimed at improving our support for mutant and transgenic lines, including (i) enhanced mutant/transgenic search functionality; (ii) more expressive phenotype curation methods; (iii) new downloads files and archival data access; (iv) incorporation of new data loads from laboratories undertaking large-scale generation of mutant or transgenic lines and (v) new GBrowse tracks for transgenic insertions, genes with antibodies and morpholinos. PMID:23074187

Howe, Douglas G.; Bradford, Yvonne M.; Conlin, Tom; Eagle, Anne E.; Fashena, David; Frazer, Ken; Knight, Jonathan; Mani, Prita; Martin, Ryan; Moxon, Sierra A. Taylor; Paddock, Holly; Pich, Christian; Ramachandran, Sridhar; Ruef, Barbara J.; Ruzicka, Leyla; Schaper, Kevin; Shao, Xiang; Singer, Amy; Sprunger, Brock; Van Slyke, Ceri E.; Westerfield, Monte

2013-01-01

231

Generation of transgenic mice with mild and severe retinal neovascularisation  

PubMed Central

Aim: To generate a mouse model for slow progressive retinal neovascularisation through vascular endothelial growth factor (VEGF) upregulation. Methods: Transgenic mice were generated via microinjection of a DNA construct containing the human VEGF165 (hVEGF) gene driven by a truncated mouse rhodopsin promoter. Mouse eyes were characterised clinically and histologically and ocular hVEGF levels assayed by ELISA. Results: One transgenic line expressing low hVEGF levels showed mild clinical changes such as focal fluorescein leakage, microaneurysms, venous tortuosity, capillary non-perfusion and minor neovascularisation, which remained stable up to 3 months postnatal. Histologically, there were some disturbance and thinning of inner and outer nuclear layers, with occasional focal areas of neovascularisation. By contrast, three other lines expressing high hVEGF levels presented with concomitantly severe phenotypes. In addition to the above, clinical features included extensive neovascularisation, haemorrhage, and retinal detachment; histologically, focal to extensive areas of neovascularisation associated with retinal folds, cell loss in the inner and outer nuclear layers, and partial retinal detachment were common. Conclusions: The authors generated four hVEGF overexpressing transgenic mouse lines with phenotypes ranging from mild to severe neovascularisation. These models are a valuable research tool to study excess VEGF related molecular and cellular changes and provide additional opportunities to test anti-angiogenic therapies. PMID:15965177

Lai, C-M; Dunlop, S A; May, L A; Gorbatov, M; Brankov, M; Shen, W-Y; Binz, N; Lai, Y KY; Graham, C E; Barry, C J; Constable, I J; Beazley, L D; Rakoczy, E P

2005-01-01

232

The a"MAZE"ing world of lung-specific transgenic mice.  

PubMed

The purpose of this review is to give a comprehensive overview of transgenic mouse lines suitable for studying gene function and cellular lineage relationships in lung development, homeostasis, injury, and repair. Many of the mouse strains reviewed in this Perspective have been widely shared within the lung research community, and new strains are continuously being developed. There are many transgenic lines that target subsets of lung cells, but it remains a challenge for investigators to select the correct transgenic modules for their experiment. This review covers the tetracycline- and tamoxifen-inducible systems and focuses on conditional lines that target the epithelial cells. We point out the limitations of each strain so investigators can choose the system that will work best for their scientific question. Current mesenchymal and endothelial lines are limited by the fact that they are not lung specific. These lines are summarized in a brief overview. In addition, useful transgenic reporter mice for studying lineage relationships, promoter activity, and signaling pathways will complete our lung-specific conditional transgenic mouse shopping list. PMID:22180870

Rawlins, Emma L; Perl, Anne-Karina

2012-03-01

233

Hypertriglyceridemia as a Result of Human Apo CIII Gene Expression in Transgenic Mice  

Microsoft Academic Search

Primary and secondary hypertriglyceridemia is common in the general population, but the biochemical basis for this disease is largely unknown. With the use of transgenic technology, two lines of mice were created that express the human apolipoprotein CIII gene. One of these mouse lines with 100 copies of the gene was found to express large amounts of the protein and

Yasushi Ito; Neal Azrolan; Anita O'Connell; Annemarie Walsh; Jan L. Breslow

1990-01-01

234

Evaluation of a morphological marker selection and excision system to generate marker-free transgenic cassava plants  

Microsoft Academic Search

The efficacy of the ipt-type Multi-Auto-Transformation (MAT) vector system to transform the extensively grown cassava cultivar “KU50” was evaluated.\\u000a This system utilizes the isopentenyltransferase (ipt) gene as morphological marker for visual selection of transgenic lines. The extreme shooty phenotype (ESP) of transgenic\\u000a lines is lost due to the removal of ipt gene mediated by the yeast Rint\\/RS system. As a

Laddawan Saelim; Salak Phansiri; Malinee Suksangpanomrung; Supatcharee Netrphan; Jarunya Narangajavana

2009-01-01

235

Phenotypic and genotypic characterization of antagonistic bacteria associated with roots of transgenic and non-transgenic potato plants.  

PubMed

Rhizobacteria obtained during a risk assessment study from parental and transgenic T4 lysozyme-expressing potato plants were investigated to determine whether or not the strains could be grouped based on the source of isolation, transgenic or non-transgenic plants, respectively. A total of 68 representative bacterial strains of the group of enterics and pseudomonads were investigated by phenotypic profiling (the antagonistic activity towards bacterial and fungal plant pathogens, the production of the plant growth hormone indole-3-acetic acid [auxin], and the sensitivity to T4 lysozyme in vitro) and genotypic profiling by PCR fingerprints using BOX primers. All isolates were identified by fatty acid methyl ester (FAME) analysis. Computer-based analysis of the phenotypic characteristics showed that both, enterics and Pseudomonas strains clustered into six to seven groups at an Euclidian distance of 10. According to their BOX-PCR-generated fingerprints the Pseudomonas strains clustered into seven groups and the enterobacteria into two groups at the same genetic distance level of 10. The majority of groups were heterogeneous and contained isolates from all plant lines. In conclusion, cluster analysis of the phenotypic and genotypic features did not reveal correlations between bacterial isolates and transgenic character of plants. PMID:11372657

Lottmann, J; Berg, G

2001-01-01

236

Decreased shoot stature and grain alpha-amylase activity following ectopic expression of a gibberellin 2-oxidase gene in transgenic wheat.  

PubMed

Ectopic expression of a gibberellin 2-oxidase gene (PcGA2ox1) decreased the content of bioactive gibberellins (GAs) in transgenic wheat, producing a range of dwarf plants with different degrees of severity. In at least one case, a single transformation event gave rise to T(1) plants with different degrees of dwarfism, the phenotypes being stably inherited over at least four generations. The dwarf phenotype, which included dark-green leaves, increased tillering and, in severe cases, a prostrate growth habit, was replicated by the application of a GA biosynthesis inhibitor to the wild type. Ear rachis length, grain set, and grain size were also decreased in the wheat transformants, compared with an azygous (null) line. The extent of post-germination alpha-amylase production in grains reflected the severity of the shoot phenotype of the transformants and both developmental processes were restored to normal by the application of gibberellic acid (GA(3)). Expression of two GA biosynthesis genes (TaGA20ox1 and TaGA3ox2) was up-regulated, and that of two alpha-amylase gene families (alpha-Amy1 and alpha-Amy2) down regulated, in scutella of semi-dwarf lines, compared with controls. The marked decline in transcript abundance of both alpha-amylase gene families in aleurone was associated with a decreased content of bioactive GAs in grains of the semi-dwarf lines. PMID:17916639

Appleford, Nigel E J; Wilkinson, Mark D; Ma, Qian; Evans, Daniel J; Stone, Marlon C; Pearce, Stephen P; Powers, Stephen J; Thomas, Stephen G; Jones, Huw D; Phillips, Andrew L; Hedden, Peter; Lenton, John R

2007-01-01

237

Detection of transgenic and endogenous plant DNA fragments in the blood, tissues, and digesta of broilers.  

PubMed

The aim was to determine the fate of transgenic and endogenous plant DNA fragments in the blood, tissues, and digesta of broilers. Male broiler chicks (n = 24) were allocated at 1 day old to each of four treatment diets designated T1-T4. T1 and T2 contained the near isogenic nongenetically modified (GM) maize grain, whereas T3 and T4 contained GM maize grain [cry1a(b) gene]; T1 and T3 also contained the near isogenic non-GM soybean meal, whereas T2 and T4 contained GM soybean meal (cp4epsps gene). Four days prior to slaughter at 39-42 days old, 50% of the broilers on T2-T4 had the source(s) of GM ingredients replaced by their non-GM counterparts. Detection of specific DNA sequences in feed, tissue, and digesta samples was completed by polymerase chain reaction analysis. Seven primer pairs were used to amplify fragments ( approximately 200 bp) from single copy genes (maize high mobility protein, soya lectin, and transgenes in the GM feeds) and multicopy genes (poultry mitochondrial cytochrome b, maize, and soya rubisco). There was no effect of treatment on the measured growth performance parameters. Except for a single detection of lectin (nontransgenic single copy gene; unsubstantiated) in the extracted DNA from one bursa tissue sample, there was no positive detection of any endogenous or transgenic single copy genes in either blood or tissue DNA samples. However, the multicopy rubisco gene was detected in a proportion of samples from all tissue types (23% of total across all tissues studied) and in low numbers in blood. Feed-derived DNA was found to survive complete degradation up to the large intestine. Transgenic DNA was detected in gizzard digesta but not in intestinal digesta 96 h after the last feeding of treatment diets containing a source of GM maize and/or soybean meal. PMID:16366726

Deaville, Eddie R; Maddison, Ben C

2005-12-28

238

A single point mutation in cyclin T1 eliminates binding to Hexim1, Cdk9 and RNA but not to AFF4 and enforces repression of HIV transcription  

PubMed Central

Background Human immunodeficiency virus (HIV) gene expression is primarily regulated at the step of transcription elongation. The viral Tat protein recruits the Positive Transcription Elongation Factor b (P-TEFb) and the Super Elongation Complex (SEC) to the HIV promoter and enhances transcription by host RNA polymerase II. Results To map residues in the cyclin box of cyclin T1 that mediate the binding of P-TEFb to its interacting host partners and support HIV transcription, a pool of N-terminal cyclin T1 mutants was generated. Binding and functional assays in cells identified specific positions in cyclin T1 that are important for (i) association of P-TEFb with Hexim1, Cdk9 and SEC/AFF4 (ii) supporting Tat-transactivation in murine cells and (iii) inhibition of basal and Tat-dependent HIV transcription in human cells. Significantly, a unique cyclin T1 mutant where a Valine residue at position 107 was mutated to Glutamate (CycT1-V107E) was identified. CycT1-V107E did not bind to Hexim1 or Cdk9, and also could not assemble on HIV TAR or 7SK-snRNA. However, it bound strongly to AFF4 and its association with HIV Tat was slightly impaired. CycT1-V107E efficiently inhibited HIV replication in human T cell lines and in CD4(+) primary cells, and enforced HIV transcription repression in T cell lines that harbor a transcriptionally silenced integrated provirus. Conclusions This study outlines the mechanism by which CycT1-V107E mutant inhibits HIV transcription and enforces viral latency. It defines the importance of N-terminal residues of cyclin T1 in mediating contacts of P-TEFb with its transcription partners, and signifies the requirement of a functional P-TEFb and SEC in mediating HIV transcription. PMID:24985467

2014-01-01

239

Relationships between LDH-A, Lactate and Metastases in 4T1 Breast Tumors  

PubMed Central

Purpose To investigate the relationship between LDH-A expression, lactate concentration, cell metabolism and metastases in murine 4T1 breast tumors. Experimental Design Inhibition of LDH-A expression and protein levels were achieved in a metastatic breast cancer cell line (4T1) using shRNA technology. The relationship between tumor LDH-A protein levels and lactate concentration (measured by magnetic resonance spectroscopic imaging-MRSI) and metastases was assessed. Results LDH-A knockdown cells (KD9) showed a significant reduction in LDH-A protein and LDH activity, less acid production, decreased transwell migration and invasion, lower proliferation, reduced glucose utilization and glycolysis and increase in oxygen consumption, ROS and cellular ATP levels, compared to control (NC) cells cultured in 25 mM glucose. In vivo studies showed lower lactate levels in KD9, KD5, KD317 tumors than in NC or 4T1 wild-type tumors (p<0.01), and a linear relationship between tumor LDH-A protein expression and lactate concentration. Metastases were delayed and primary tumor growth rate decreased. Conclusions We show for the first time that LDH-A knockdown inhibited the formation of metastases, and was accompanied by in vivo changes in tumor cell metabolism. Lactate MRSI can be used as a surrogate to monitor targeted inhibition of LDH-A in a pre-clinical setting and provides a non-invasive imaging strategy to monitor LDH-A targeted therapy. This imaging strategy can be translated to the clinic to identify and monitor patients who are at high risk of developing metastatic disease. PMID:23833310

Rizwan, Asif; Serganova, Inna; Khanin, Raya; Karabeber, Hazem; Ni, Xiaohui; Thakur, Sunitha; Zakian, Kristen L.; Blasberg, Ronald; Koutcher, Jason A.

2013-01-01

240

Effect of Air Ions on Submicron T1 Bacteriophage Aerosols  

PubMed Central

The effect of a high concentration of ionized air molecules on sampling T1 phage aerosols of submicron particle size was evaluated by comparing the phage recoveries of all-glass impingers (AGI-4) and type 6 filter papers. Sampler recoveries of all ionized aerosols were less than the recoveries of nonionized control aerosols. These reductions in recovery were greater with positive ions than with negative ions or ions of mixed polarity. The AGI-4 allowed considerable slippage, which was not affected by the air ions. Type 6 filter paper recoveries were less than AGI-4 recoveries. The air ions did not appear to affect the aerosol particle size as determined by an electron microscope. Images Fig. 1 Fig. 3 PMID:16349691

Happ, John W.; Harstad, J. Bruce; Buchanan, Lee M.

1966-01-01

241

Gamow-Teller Decay of the T=1 54Ni  

E-print Network

Under the assumption that isospin is a good quantum number, symmetry is expected for the transitions from ground state of the pair T=1, T$_Z$=$\\pm$1 nuclei to the excited states of the T=0 nucleus situated betweem them. To study the isospin symmetry of these transitions in mass A=54, we have performed two different experiment: 1) High resolution charge exchange reactions at RCNP (Osaka) for the T$_Z$=+1 $\\rightarrow$ 0. 2) $\\beta$-decay experiment a Louvain la Neuve. \\\\ The present work shows the first results in the analysis of the $\\beta$-decay experiment as part of the Diploma and PhD thesis of Francisco Molina Palacios at Instituto de Fisica Corpuscular in Valencia.

Francisco Gabriel Molina Palacios

2010-06-04

242

Insertional mutagenesis in transgenic mice  

SciTech Connect

The molecular analysis of mutations in the mouse is an ideal way of establishing structure-function relationships between individual genes and complex developmental phenotypes. Insertional mutations, caused by the integration of a transgene, are advantageous because the mutant locus is tagged' with the exogenously added DNA and can be accessed with existing cloning and molecular analysis techniques. The authors have implemented a large-scale insertional mutagenesis program at the Oak Ridge National Laboratory in an effort to identify numerous mutations with developmental phenotypes. Several of these mutations are currently being subjected to an in-depth molecular analysis involving the characterization of the structure and expression of the mutant locus. Additionally, the authors are mapping transgene integration sites with in situ hybridization procedures, which will result in additional well-characterized molecular access points for the mouse genome.

Woychik, R.P.; Bultman, S.J.; Schrick, J.J.; Moyer, J.H.; Beatty, B.R.; Godfrey, V.L.; Selby, P.B. (Oak Ridge National Lab., TN (United States))

1991-03-11

243

MAIN-BELT COMET P/2012 T1 (PANSTARRS)  

SciTech Connect

We present initial results from observations and numerical analyses aimed at characterizing the main-belt comet P/2012 T1 (PANSTARRS). Optical monitoring observations were made between 2012 October and 2013 February using the University of Hawaii 2.2 m telescope, the Keck I telescope, the Baade and Clay Magellan telescopes, Faulkes Telescope South, the Perkins Telescope at Lowell Observatory, and the Southern Astrophysical Research Telescope. The object's intrinsic brightness approximately doubles from the time of its discovery in early October until mid-November and then decreases by {approx}60% between late December and early February, similar to photometric behavior exhibited by several other main-belt comets and unlike that exhibited by disrupted asteroid (596) Scheila. We also used Keck to conduct spectroscopic searches for CN emission as well as absorption at 0.7 {mu}m that could indicate the presence of hydrated minerals, finding an upper limit CN production rate of Q{sub CN} < 1.5 Multiplication-Sign 10{sup 23} mol s{sup -1}, from which we infer a water production rate of Q{sub H{sub 2O}}<5 Multiplication-Sign 10{sup 25} mol s{sup -1}, and no evidence of the presence of hydrated minerals. Numerical simulations indicate that P/2012 T1 is largely dynamically stable for >100 Myr and is unlikely to be a recently implanted interloper from the outer solar system, while a search for potential asteroid family associations reveals that it is dynamically linked to the {approx}155 Myr old Lixiaohua asteroid family.

Hsieh, Henry H.; Kaluna, Heather M.; Yang Bin; Haghighipour, Nader; Micheli, Marco; Denneau, Larry; Jedicke, Robert; Kleyna, Jan; Veres, Peter; Wainscoat, Richard J.; Ansdell, Megan; Elliott, Garrett T.; Keane, Jacqueline V.; Meech, Karen J.; Riesen, Timm E.; Sonnett, Sarah [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Novakovic, Bojan [Department of Astronomy, Faculty of Mathematics, University of Belgrade, Studentski trg 16, 11000 Belgrade (Serbia); Fitzsimmons, Alan [Astrophysics Research Centre, Queens University Belfast, Belfast BT7 1NN (United Kingdom); Moskovitz, Nicholas A. [Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Sheppard, Scott S., E-mail: hsieh@ifa.hawaii.edu [Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, NW, Washington, DC 20015 (United States); and others

2013-07-01

244

Functional screening of an asthma QTL in YAC transgenic mice  

SciTech Connect

While large numbers of quantitative trait loci (QTLs) contributing to genetically complex conditions have been discovered, few causative genes have been identified. This is mainly due to the large size of QTLs and the subtle connection between genotype and quantitative phenotype associated with these conditions. While large numbers of quantitative trait loci (QTLs) contributing to genetically complex conditions have been discovered, few causative genes have been identified. This is mainly due to the large size of QTLs and the subtle connection between genotype and quantitative phenotype associated with these conditions. To screen for genes contributing to an asthma QTL mapped to human chromosome 5q33, the authors characterized a panel of large-insert 5q31 transgenics based on studies demonstrating that altering gene dosage frequently affects quantitative phenotypes normally influenced by that gene. This panel of human YAC transgenics, propagating a one megabase interva2048 chromosome 5q31 containing 23 genes, was screened for quantitative changes in several asthma-associated phenotypes. Multiple independent transgenic lines with altered IgE response to antigen treatment shared a 180 kb region containing 5 genes, including human interleukin 4 (IL4) and interleukin 13 (IL13), which induce IgE class switching in B cells5. Further analysis of these mice and mice transgenic for only murine Il4 and Il13 demonstrated that moderate changes in murine Il4 and Il13 expression affect asthma-associated phenotypes in vivo. This functional screen of large-insert transgenics enabled them to sift through multiple genes in the 5q3 asthma QTL without prior consideration of assumed individual gene function and identify genes that influence the QTL phenotype in vivo.

Symula, Derek J.; Frazer, Kelly A.; Ueda, Yukihiko; Denefle, Patrice; Stevens, Mary E.; Wang, Zhi-En; Locksley, Richard; Rubin, Edward M.

1999-07-02

245

Transgene delivery via intracellular electroporetic nanoinjection.  

PubMed

Development of an effective cytoplasmic delivery technique has remained an elusive goal for decades despite the success of pronuclear microinjection. Cytoplasmic injections are faster and easier than pronuclear injection and do not require the pronuclei to be visible; yet previous attempts to develop cytoplasmic injection have met with limited success. In this work we report a cytoplasmic delivery method termed intracellular electroporetic nanoinjection (IEN). IEN is unique in that it manipulates transgenes using electrical forces. The microelectromechanical system (MEMS) uses electrostatic charge to physically pick up transgenes and place them in the cytoplasm. The transgenes are then propelled through the cytoplasm and electroporated into the pronuclei using electrical pulses. Standard electroporation of whole embryos has not resulted in transgenic animals, but the MEMS device allows localized electroporation to occur within the cytoplasm for transgene delivery from the cytoplasm to the pronucleus. In this report we describe the principles which allow localized electroporation of the pronuclei including: the location of mouse pronuclei between 21 and 28 h post-hCG treatment, modeling data predicting the voltages needed for localized electroporation of pronuclei, and data on electric-field-driven movement of transgenes. We further report results of an IEN versus microinjection comparative study in which IEN produced transgenic pups with viability, transgene integration, and expression rates statistically comparable to microinjection. The ability to perform injections without visualizing or puncturing the pronuclei will widely benefit transgenic research, and will be particularly advantageous for the production of transgenic animals with embryos exhibiting reduced pronuclear visibility. PMID:23532407

Wilson, Aubrey M; Aten, Quentin T; Toone, Nathan C; Black, Justin L; Jensen, Brian D; Tamowski, Susan; Howell, Larry L; Burnett, Sandra H

2013-10-01

246

Stacking of antimicrobial genes in potato transgenic plants confers increased resistance to bacterial and fungal pathogens.  

PubMed

Solanum tuberosum plants were transformed with three genetic constructions expressing the Nicotiana tabacum AP24 osmotine, Phyllomedusa sauvagii dermaseptin and Gallus gallus lysozyme, and with a double-transgene construction expressing the AP24 and lysozyme sequences. Re-transformation of dermaseptin-transformed plants with the AP24/lysozyme construction allowed selection of plants simultaneously expressing the three transgenes. Potato lines expressing individual transgenes or double- and triple-transgene combinations were assayed for resistance to Erwinia carotovora using whole-plant and tuber infection assays. Resistance levels for both infection tests compared consistently for most potato lines and allowed selection of highly resistant phenotypes. Higher resistance levels were found in lines carrying the dermaseptin and lysozyme sequences, indicating that theses proteins are the major contributors to antibacterial activity. Similar results were obtained in tuber infection tests conducted with Streptomyces scabies. Plant lines showing the higher resistance to bacterial infections were challenged with Phytophthora infestans, Rhizoctonia solani and Fusarium solani. Considerable levels of resistance to each of these pathogens were evidenced employing semi-quantitative tests based in detached-leaf inoculation, fungal growth inhibition and in vitro plant inoculation. On the basis of these results, we propose that stacking of these transgenes is a promising approach to achieve resistance to both bacterial and fungal pathogens. PMID:22115953

Rivero, Mercedes; Furman, Nicolás; Mencacci, Nicolás; Picca, Pablo; Toum, Laila; Lentz, Ezequiel; Bravo-Almonacid, Fernando; Mentaberry, Alejandro

2012-01-20

247

Targeting gene expression to the female larval fat body of transgenic Aedes aegypti mosquitoes  

PubMed Central

As the fat body is a critical tissue for mosquito development, metamorphosis, immune and reproductive system function, characterization of regulatory modules targeting gene expression to the female mosquito fat body at distinct life stages is much needed for multiple, varied strategies for controlling vector-borne diseases such as dengue and malaria. The hexameric storage protein, Hexamerin-1.2, of the mosquito, Aedes atropalpus, is female-specific and uniquely expressed in the fat body of fourth-instar larvae and young adults. We have identified in the Hex-1.2 gene, a short regulatory module that directs female-, tissue-, and stage-specific lacZ reporter gene expression using a heterologous promoter in transgenic lines of the dengue vector, Aedes aegypti. Male transgenic larvae and pupae of one line expressed no E. coli ?-galactosidase or transgene product; in two other lines reporter gene activity was highly female-biased. All transgenic lines expressed the reporter only in the fat body. However, lacZ mRNA levels were no different in males and females at all stages examined, suggesting that the gene regulatory module drives female-specific expression by post-transcriptional regulation in the heterologous mosquito. This regulatory element from the Hex-1.2 gene thus provides a new molecular tool for transgenic mosquito control as well as functional genetic analysis in aedine mosquitoes. PMID:23241066

TOTTEN, Daniel C.; VUONG, Mai; LITVINOVA, Oksana V.; JINWAL, Umesh K.; GULIA-NUSS, Monika; HARRELL, Robert A.; BENES, Helen

2014-01-01

248

cis-acting DNA regulatory elements, including the retinoic acid response element, are required for tissue specific laminin B1 promoter \\/lacZ expression in transgenic mice  

Microsoft Academic Search

The LAMB1 gene encodes the laminin ?1 subunit of laminin, an extracellular matrix protein. Using several transgenic mouse lines containing various lengths of the LAMB1 promoter driving lacZ reporter gene expression, regions of LAMB1 promoter that contain cis-acting DNA regulatory element(s) have been identified. The 3.9LAMB1?gal transgene is expressed in various tissues during development. LAMB1 transgene expression is observed in

Karim A. Sharif; Congyi Li; Lorraine J. Gudas

2001-01-01

249

Overexpression of the vimentin gene in transgenic mice inhibits normal lens cell differentiation  

PubMed Central

To investigate the role of the intermediate filament protein vimentin in the normal differentiation and morphogenesis of the eye lens fiber cells, we generated transgenic mice bearing multiple copies of the chicken vimentin gene. In most cases, the vimentin transgene was overexpressed in the lenses of these animals, reaching up to 10 times the endogenous levels. This high expression of vimentin interfered very strongly with the normal differentiation of the lens fibers. The normal fiber cell denucleation and elongation processes were impaired and the animals developed pronounced cataracts, followed by extensive lens degeneration. The age of appearance and extent of these abnormalities in the different transgenic lines were directly related to the vimentin level. Electron microscopic analysis revealed that the accumulated transgenic protein forms normal intermediate filaments. PMID:2793935

1989-01-01

250

A transgenic zebrafish model of targeted oocyte ablation and de novo oogenesis.  

PubMed

We describe here a novel transgenic zebrafish, Tg(zpc:G4VP16/UAS:nfsB-mCherry) that effectively demonstrates the targeted oocyte ablation in the adult zebrafish ovary. This transgenic line expresses bacterial nitroreductase enzyme (nfsB) under the control of the oocyte-specific zona pellucida C (zpc) gene promoter. Adult transgenic females exposed to the prodrug metronidazole demonstrated near-complete ablation of growing oocytes, resulting in ovarian degeneration and complete cessation of reproductive function. Within 4 weeks of prodrug removal, treated fish demonstrated complete anatomical regeneration of the ovary and, within 7 weeks, ovarian function (fertility) was fully restored. Together, these results demonstrate functional renewal of the oocyte pool in the adult zebrafish ovary. Accordingly, this transgenic zebrafish model system provides a novel means to investigate ovarian growth dynamics in a genetically tractable vertebrate, and may be useful for evaluating signaling interactions that regulate gonadal development processes such as de novo oogenesis. PMID:21761478

White, Yvonne A R; Woods, Dori C; Wood, Antony W

2011-08-01

251

Role of nutrient-sensing taste 1 receptor (T1R) family members in gastrointestinal chemosensing.  

PubMed

Luminal nutrient sensing by G-protein-coupled receptors (GPCR) expressed on the apical domain of enteroendocrine cells activates intracellular pathways leading to secretion of gut hormones that control vital physiological processes such as digestion, absorption, food intake and glucose homeostasis. The taste 1 receptor (T1R) family of GPCR consists of three members: T1R1; T1R2; T1R3. Expression of T1R1, T1R2 and T1R3 at mRNA and protein levels has been demonstrated in the intestinal tissue of various species. It has been shown that T1R2-T1R3, in association with G-protein gustducin, is expressed in intestinal K and L endocrine cells, where it acts as the intestinal glucose (sweet) sensor. A number of studies have demonstrated that activation of T1R2-T1R3 by natural sugars and artificial sweeteners leads to secretion of glucagon-like peptides 1&2 (GLP-1 and GLP-2) and glucose dependent insulinotropic peptide (GIP). GLP-1 and GIP enhance insulin secretion; GLP-2 increases intestinal growth and glucose absorption. T1R1-T1R3 combination co-expressed on the apical domain of cholecystokinin (CCK) expressing cells is a luminal sensor for a number of L-amino acids; with amino acid-activation of the receptor eliciting CCK secretion. This article focuses on the role of the gut-expressed T1R1, T1R2 and T1R3 in intestinal sweet and L-amino acid sensing. The impact of exploiting T1R2-T1R3 as a nutritional target for enhancing intestinal glucose absorption and gut structural maturity in young animals is also highlighted. PMID:24382171

Shirazi-Beechey, Soraya P; Daly, Kristian; Al-Rammahi, Miran; Moran, Andrew W; Bravo, David

2014-06-01

252

Comparative analysis of transgenic tall fescue (Festuca arundinacea Schreb.) plants obtained by Agrobacterium-mediated transformation and particle bombardment.  

PubMed

Agrobacterium-mediated transformation and particle bombardment are the two most widely used methods for genetically modifying grasses. Here, these two systems are compared for transformation efficiency, transgene integration and transgene expression when used to transform tall fescue (Festuca arundinacea Schreb.). The bar gene was used as a selectable marker and selection during tissue culture was performed using 2 mg/l bialaphos in both callus induction and regeneration media. Average transformation efficiency across the four callus lines used in the experiments was 10.5% for Agrobacterium-mediated transformation and 11.5% for particle bombardment. Similar transgene integration patterns and co-integration frequencies of bar and uidA were observed in both gene transfer systems. However, while GUS activity was detected in leaves of 53% of the Agrobacterium transformed lines, only 20% of the bombarded lines showed GUS activity. Thus, Agrobacterium-mediated transformation appears to be the preferred method for producing transgenic tall fescue plants. PMID:18648817

Gao, Caixia; Long, Danfeng; Lenk, Ingo; Nielsen, Klaus Kristian

2008-10-01

253

The CP4 transgene provides high levels of tolerance to Roundup ® herbicide in field-grown hybrid poplars  

Microsoft Academic Search

We tested two genes together in hybrid poplars (genus Populus), CP4 and GOX, for imparting tolerance to glyphosate (the active ingredient in Roundup® herbicide). Using Agrobacterium-based transformation, 80 independent transgenic lines (i.e., products of asexual gene transfer) were produced in a variety of hybrid poplar clones (40 lines in Populus trichocarpa Torr. & Gray × Populus deltoides Bartr., 35 lines

R. Meilan; K.-H. Han; C. Ma; S. P. DiFazio; J. A. Eaton; E. A. Hoien; B. J. Stanton; R. P. Crockett; M. L. Taylor; R. R. James; J. S. Skinner; L. Jouanin; G. Pilate; S. H. Strauss

2002-01-01

254

Transgenic Crops: An Introduction and Resource Guide  

NSDL National Science Digital Library

Developed by four professors in the Soil and Crops Sciences and Life Sciences Departments at Colorado State University, this site aims to "provide balanced information and links to other resources on the technology and issues surrounding transgenic crops (also known as genetically modified or GM crops)." None of the authors is affiliated with companies involved in transgenic crop development or with groups campaigning against such crops. The site covers topics such as plant breeding, how transgenic crops are made -- including a Flash demo (not working at time of review), regulation of transgenic crops, current and future transgenic products, risks and concerns, and news updates. The authors deliberately steer clear of the moral or ethical implications of transgenic technology, staying focused on the scientific issues. Throughout the site, links are provided to related sites and other resources. Other sections include a bibliography, quiz, and FAQ.

255

Drug inhibition of Gly-Sar uptake and hPepT1 localization using hPepT1GFP fusion protein  

Microsoft Academic Search

An hPepT1-GFP fusion construct was made to study drug inhibition of dipeptide uptake and apical, basolateral, or subcellular\\u000a hPepT1 localization. The hPepT1 stop codon was mutated by polymerase chain reaction and was subsequently cloned into the pEGFP-N1\\u000a vector. The hPepT1-GFP fusion construct was then transfected into Caco-2 and HeLa cells, and drug inhibition was studied by\\u000a inhibiting 3H-Gly-Sar uptake. Western

Duxin Sun; Christopher P. Landowski; Xiaoyan Chu; Richard Wallsten; David Fleisher; Gordon L. Amidon; Thomas E. Komorowski

2001-01-01

256

Different functional roles of T1R subunits in the heteromeric taste receptors.  

PubMed

The T1R receptors, a family of taste-specific class C G protein-coupled receptors, mediate mammalian sweet and umami tastes. The structure-function relationships of T1R receptors remain largely unknown. In this study, we demonstrate the different functional roles of T1R extracellular and transmembrane domains in ligand recognition and G protein coupling. Similar to other family C G protein-coupled receptors, the N-terminal Venus flytrap domain of T1R2 is required for recognizing sweeteners, such as aspartame and neotame. The G protein coupling requires the transmembrane domain of T1R2. Surprisingly, the C-terminal transmembrane domain of T1R3 is required for recognizing sweetener cyclamate and sweet taste inhibitor lactisole. Because T1R3 is the common subunit in the sweet taste receptor and the umami taste receptor, we tested the interaction of lactisole and cyclamate with the umami taste receptor. Lactisole inhibits the activity of the human T1R1/T1R3 receptor, and, as predicted, blocked the umami taste of l-glutamate in human taste tests. Cyclamate does not activate the T1R1/T1R3 receptor by itself, but potentiates the receptor's response to l-glutamate. Taken together, these findings demonstrate the different functional roles of T1R3 and T1R2 and the presence of multiple ligand binding sites on the sweet taste receptor. PMID:15353592

Xu, Hong; Staszewski, Lena; Tang, Huixian; Adler, Elliot; Zoller, Mark; Li, Xiaodong

2004-09-28

257

Different functional roles of T1R subunits in the heteromeric taste receptors  

PubMed Central

The T1R receptors, a family of taste-specific class C G proteincoupled receptors, mediate mammalian sweet and umami tastes. The structure–function relationships of T1R receptors remain largely unknown. In this study, we demonstrate the different functional roles of T1R extracellular and transmembrane domains in ligand recognition and G protein coupling. Similar to other family C G protein-coupled receptors, the N-terminal Venus flytrap domain of T1R2 is required for recognizing sweeteners, such as aspartame and neotame. The G protein coupling requires the transmembrane domain of T1R2. Surprisingly, the C-terminal transmembrane domain of T1R3 is required for recognizing sweetener cyclamate and sweet taste inhibitor lactisole. Because T1R3 is the common subunit in the sweet taste receptor and the umami taste receptor, we tested the interaction of lactisole and cyclamate with the umami taste receptor. Lactisole inhibits the activity of the human T1R1/T1R3 receptor, and, as predicted, blocked the umami taste of l-glutamate in human taste tests. Cyclamate does not activate the T1R1/T1R3 receptor by itself, but potentiates the receptor's response to l-glutamate. Taken together, these findings demonstrate the different functional roles of T1R3 and T1R2 and the presence of multiple ligand binding sites on the sweet taste receptor. PMID:15353592

Xu, Hong; Staszewski, Lena; Tang, Huixian; Adler, Elliot; Zoller, Mark; Li, Xiaodong

2004-01-01

258

Main-belt Comet P/2012 T1 (PANSTARRS)  

NASA Astrophysics Data System (ADS)

We present initial results from observations and numerical analyses aimed at characterizing the main-belt comet P/2012 T1 (PANSTARRS). Optical monitoring observations were made between 2012 October and 2013 February using the University of Hawaii 2.2 m telescope, the Keck I telescope, the Baade and Clay Magellan telescopes, Faulkes Telescope South, the Perkins Telescope at Lowell Observatory, and the Southern Astrophysical Research Telescope. The object's intrinsic brightness approximately doubles from the time of its discovery in early October until mid-November and then decreases by ~60% between late December and early February, similar to photometric behavior exhibited by several other main-belt comets and unlike that exhibited by disrupted asteroid (596) Scheila. We also used Keck to conduct spectroscopic searches for CN emission as well as absorption at 0.7 ?m that could indicate the presence of hydrated minerals, finding an upper limit CN production rate of Q CN < 1.5 × 1023 mol s-1, from which we infer a water production rate of Q_H_2O<5\\times 10^{25} mol s-1, and no evidence of the presence of hydrated minerals. Numerical simulations indicate that P/2012 T1 is largely dynamically stable for >100 Myr and is unlikely to be a recently implanted interloper from the outer solar system, while a search for potential asteroid family associations reveals that it is dynamically linked to the ~155 Myr old Lixiaohua asteroid family. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration, and made possible by the generous financial support of the W. M. Keck Foundation, the Magellan Telescopes located at Las Campanas Observatory, Chile, and the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia, e Inovação (MCTI) da República Federativa do Brasil, the U.S. National Optical Astronomy Observatory (NOAO), the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU).

Hsieh, Henry H.; Kaluna, Heather M.; Novakovi?, Bojan; Yang, Bin; Haghighipour, Nader; Micheli, Marco; Denneau, Larry; Fitzsimmons, Alan; Jedicke, Robert; Kleyna, Jan; Vereš, Peter; Wainscoat, Richard J.; Ansdell, Megan; Elliott, Garrett T.; Keane, Jacqueline V.; Meech, Karen J.; Moskovitz, Nicholas A.; Riesen, Timm E.; Sheppard, Scott S.; Sonnett, Sarah; Tholen, David J.; Urban, Laurie; Kaiser, Nick; Chambers, K. C.; Burgett, William S.; Magnier, Eugene A.; Morgan, Jeffrey S.; Price, Paul A.

2013-07-01

259

Effects of Transgenic Cry1Ac + CpTI Cotton on Non-Target Mealybug Pest Ferrisia virgata and Its Predator Cryptolaemus montrouzieri  

PubMed Central

Recently, several invasive mealybugs (Hemiptera: Pseudococcidae) have rapidly spread to Asia and have become a serious threat to the production of cotton including transgenic cotton. Thus far, studies have mainly focused on the effects of mealybugs on non-transgenic cotton, without fully considering their effects on transgenic cotton and trophic interactions. Therefore, investigating the potential effects of mealybugs on transgenic cotton and their key natural enemies is vitally important. A first study on the effects of transgenic cotton on a non-target mealybug, Ferrisia virgata (Cockerell) (Hemiptera: Pseudococcidae) was performed by comparing its development, survival and body weight on transgenic cotton leaves expressing Cry1Ac (Bt toxin) + CpTI (Cowpea Trypsin Inhibitor) with those on its near-isogenic non-transgenic line. Furthermore, the development, survival, body weight, fecundity, adult longevity and feeding preference of the mealybug predator Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) was assessed when fed F. virgata maintained on transgenic cotton. In order to investigate potential transfer of Cry1Ac and CpTI proteins via the food chain, protein levels in cotton leaves, mealybugs and ladybirds were quantified. Experimental results showed that F. virgata could infest this bivalent transgenic cotton. No significant differences were observed in the physiological parameters of the predator C. montrouzieri offered F. virgata reared on transgenic cotton or its near-isogenic line. Cry1Ac and CpTI proteins were detected in transgenic cotton leaves, but no detectable levels of both proteins were present in the mealybug or its predator when reared on transgenic cotton leaves. Our bioassays indicated that transgenic cotton poses a negligible risk to the predatory coccinellid C. montrouzieri via its prey, the mealybug F. virgata. PMID:24751821

Wu, Hongsheng; Zhang, Yuhong; Liu, Ping; Xie, Jiaqin; He, Yunyu; Deng, Congshuang; De Clercq, Patrick; Pang, Hong

2014-01-01

260

Effects of transgenic Cry1Ac + CpTI cotton on non-target mealybug pest Ferrisia virgata and its predator Cryptolaemus montrouzieri.  

PubMed

Recently, several invasive mealybugs (Hemiptera: Pseudococcidae) have rapidly spread to Asia and have become a serious threat to the production of cotton including transgenic cotton. Thus far, studies have mainly focused on the effects of mealybugs on non-transgenic cotton, without fully considering their effects on transgenic cotton and trophic interactions. Therefore, investigating the potential effects of mealybugs on transgenic cotton and their key natural enemies is vitally important. A first study on the effects of transgenic cotton on a non-target mealybug, Ferrisia virgata (Cockerell) (Hemiptera: Pseudococcidae) was performed by comparing its development, survival and body weight on transgenic cotton leaves expressing Cry1Ac (Bt toxin) + CpTI (Cowpea Trypsin Inhibitor) with those on its near-isogenic non-transgenic line. Furthermore, the development, survival, body weight, fecundity, adult longevity and feeding preference of the mealybug predator Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) was assessed when fed F. virgata maintained on transgenic cotton. In order to investigate potential transfer of Cry1Ac and CpTI proteins via the food chain, protein levels in cotton leaves, mealybugs and ladybirds were quantified. Experimental results showed that F. virgata could infest this bivalent transgenic cotton. No significant differences were observed in the physiological parameters of the predator C. montrouzieri offered F. virgata reared on transgenic cotton or its near-isogenic line. Cry1Ac and CpTI proteins were detected in transgenic cotton leaves, but no detectable levels of both proteins were present in the mealybug or its predator when reared on transgenic cotton leaves. Our bioassays indicated that transgenic cotton poses a negligible risk to the predatory coccinellid C. montrouzieri via its prey, the mealybug F. virgata. PMID:24751821

Wu, Hongsheng; Zhang, Yuhong; Liu, Ping; Xie, Jiaqin; He, Yunyu; Deng, Congshuang; De Clercq, Patrick; Pang, Hong

2014-01-01

261

Proteomic analysis of known and candidate rice allergens between non-transgenic and transgenic plants  

Microsoft Academic Search

Salt-soluble proteins extracted from non-transgenic and transgenic rice were evaluated for the presence of known and potential allergens by proteomic techniques. The salt-soluble proteins were extracted, separated by 1D and 2D electrophoresis, and analyzed by Western blotting. 1D immunoblot analysis with patients’ sera revealed few qualitative differences between the IgE-binding proteins of the non-transgenic and transgenic rice. 1D immunoblot with

Rie Satoh; Rika Nakamura; Akira Komatsu; Masahiro Oshima; Reiko Teshima

2011-01-01

262

Field assessment of outcrossing from transgenic pea (Pisum sativum L.) plants.  

PubMed

The frequency of outcrossing from a transgenic line of peas into three cultivars ('Carneval', 'Montana', 'Tipu') was studied in the field in 1997 and 1999. Two dominant traits, normal leaf form and a highly-expressed beta-glucuronidase (gusA) gene, were used as markers of pollen transfer. Because of heterogeneity in the commercial seed sources, leaf form alone was unreliable for assessing pollen migration into 'trap' plants. Of approximately 9000 offspring tested, only five plants scored positive for the presence of both markers. All five were located in 'trap' plots situated near the transgenic line. This represents a mean outcrossing rate of 0.07%. PMID:12437082

Polowic, Patricia L; Vandenberg, Albert; Mahon, John D

2002-10-01

263

Main-Belt Comet P/2012 T1 (PANSTARRS)  

E-print Network

We present initial results from observations and numerical analyses aimed at characterizing main-belt comet P/2012 T1 (PANSTARRS). Optical monitoring observations were made between October 2012 and February 2013 using the University of Hawaii 2.2 m telescope, the Keck I telescope, the Baade and Clay Magellan telescopes, Faulkes Telescope South, the Perkins Telescope at Lowell Observatory, and the Southern Astrophysical Research (SOAR) telescope. The object's intrinsic brightness approximately doubles from the time of its discovery in early October until mid-November and then decreases by ~60% between late December and early February, similar to photometric behavior exhibited by several other main-belt comets and unlike that exhibited by disrupted asteroid (596) Scheila. We also used Keck to conduct spectroscopic searches for CN emission as well as absorption at 0.7 microns that could indicate the presence of hydrated minerals, finding an upper limit CN production rate of QCN100 Myr and is unlikely to be a rec...

Hsieh, Henry H; Novakovic, Bojan; Yang, Bin; Haghighipour, Nader; Micheli, Marco; Denneau, Larry; Fitzsimmons, Alan; Jedicke, Robert; Kleyna, Jan; Veres, Peter; Wainscoat, Richard J; Ansdell, Megan; Elliott, Garrett T; Keane, Jacqueline V; Meech, Karen J; Moskovitz, Nicholas A; Riesen, Timm E; Sheppard, Scott S; Sonnett, Sarah; Tholen, David J; Urban, Laurie; Kaiser, Nick; Chambers, K C; Burgett, William S; Magnier, Eugene A; Morgan, Jeffrey S; Price, Paul A

2013-01-01

264

Resolution enhanced T1-insensitive steady-state imaging.  

PubMed

Resolution enhanced T(1)-insensitive steady-state imaging (RE-TOSSI) is a new MRI pulse sequence for the generation of rapid T(2) contrast with high spatial resolution. TOSSI provides T(2) contrast by using nonequally spaced inversion pulses throughout a balanced steady-state free precession (SSFP) acquisition. In RE-TOSSI, these energy and time intensive adiabatic inversion pulses and associated magnetization preparation are removed from TOSSI after acquisition of the data around the center of k-space. Magnetization evolution simulations demonstrate T(2) contrast in TOSSI as well as reduction in the widening of the point spread function width (by up to a factor of 4) to a near ideal case for RE-TOSSI. Phantom experimentation is used to characterize and compare the contrast and spatial resolution properties of TOSSI, RE-TOSSI, balanced SSFP, Half-Fourier Acquisition Single-Shot Turbo Spin Echo (HASTE), and turbo spin echo and to optimize the fraction of k-space acquired using TOSSI. Comparison images in the abdomen and brain demonstrate similar contrast and improved spatial resolution in RE-TOSSI compared with TOSSI; comparison balanced SSFP, HASTE, and turbo spin echo images are provided. RE-TOSSI is capable of providing high spatial resolution T(2)-weighted images in 1 s or less per image. PMID:22131264

Derakhshan, Jamal J; Nour, Sherif G; Sunshine, Jeffrey L; Griswold, Mark A; Duerk, Jeffrey L

2012-08-01

265

The interplay of T1- and T2-relaxation on T1-weighted MRI of hMSCs induced by Gd-DOTA-peptides.  

PubMed

Three Gd-DOTA-peptide complexes with different peptide sequence are synthesized and used as T1 contrast agent to label human mesenchymal stem cells (hMSCs) for magnetic resonance imaging study. The peptides include a universal cell penetrating peptide TAT, a linear MSC-specific peptide EM7, and a cyclic MSC-specific peptide CC9. A significant difference in labeling efficacy is observed between the Gd-DOTA-peptides as well as a control Dotarem. All Gd-DOTA-peptides as well as Dotarem induce significant increase in T1 relaxation rate which is in favor of T1-weighted MR imaging. Gd-DOTA-CC9 yields the maximum labeling efficacy but poor T1 contrast enhancement. Gd-DOTA-EM7 yields the minimum labeling efficacy but better T1 contrast enhancement. Gd-DOTA-TAT yields a similar labeling efficacy as Gd-DOTA-CC9 and similar T1 contrast enhancement as Gd-DOTA-EM7. The underlying mechanism that governs T1 contrast enhancement effect is discussed. Our results suggest that T1 contrast enhancement induced by Gd-DOTA-peptides depends not only on the introduced cellular Gd content, but more importantly on the effect that Gd-DOTA-peptides exert on the T1-relaxation and T2-relaxation processes/rates. Both T1 and particularly T2 relaxation rate have to be taken into account to interpret T1 contrast enhancement. In addition, the interpretation has to be based on cellular instead of aqueous longitudinal and transverse relaxivities of Gd-DOTA-peptides. PMID:24560458

Cao, Limin; Li, Binbin; Yi, Peiwei; Zhang, Hailu; Dai, Jianwu; Tan, Bo; Deng, Zongwu

2014-04-01

266

An inducible krasV12 transgenic zebrafish model for liver tumorigenesis and chemical drug screening  

PubMed Central

SUMMARY Because Ras signaling is frequently activated by major hepatocellular carcinoma etiological factors, a transgenic zebrafish constitutively expressing the krasV12 oncogene in the liver was previously generated by our laboratory. Although this model depicted and uncovered the conservation between zebrafish and human liver tumorigenesis, the low tumor incidence and early mortality limit its use for further studies of tumor progression and inhibition. Here, we employed a mifepristone-inducible transgenic system to achieve inducible krasV12 expression in the liver. The system consisted of two transgenic lines: the liver-driver line had a liver-specific fabp10 promoter to produce the LexPR chimeric transactivator, and the Ras-effector line contained a LexA-binding site to control EGFP-krasV12 expression. In double-transgenic zebrafish (driver-effector) embryos and adults, we demonstrated mifepristone-inducible EGFP-krasV12 expression in the liver. Robust and homogeneous liver tumors developed in 100% of double-transgenic fish after 1 month of induction and the tumors progressed from hyperplasia by 1 week post-treatment (wpt) to carcinoma by 4 wpt. Strikingly, liver tumorigenesis was found to be ‘addicted’ to Ras signaling for tumor maintenance, because mifepristone withdrawal led to tumor regression via cell death in transgenic fish. We further demonstrated the potential use of the transparent EGFP-krasV12 larvae in inhibitor treatments to suppress Ras-driven liver tumorigenesis by targeting its downstream effectors, including the Raf-MEK-ERK and PI3K-AKT-mTOR pathways. Collectively, this mifepristone-inducible and reversible krasV12 transgenic system offers a novel model for understanding hepatocarcinogenesis and a high-throughput screening platform for anti-cancer drugs. PMID:21903676

Nguyen, Anh Tuan; Emelyanov, Alexander; Koh, Chor Hui Vivien; Spitsbergen, Jan M.; Parinov, Serguei; Gong, Zhiyuan

2012-01-01

267

Detection of genomic changes in transgenic Bt rice populations through genetic fingerprinting using amplified fragment length polymorphism (AFLP).  

PubMed

A highly precise molecular marker technique, Amplified Fragment Length Polymorphism (AFLP) was used to characterize the changes in genomic structure occurred due to introduction of foreign gene and/ or due to the induced tissue culture stress during the development of various transgenic Bt rice populations. The transgenic rice plants having complex to simple Bt gene and selectable marker gene organizations were selected from the six insect resistant Bt rice lines. Our results clearly demonstrate that integration pattern, extent of rearrangement of foreign DNA and method of transformation may influence the genomic changes in transgenic rice populations. Eleven of fourteen AFLP primer combinations tested, generated distinct scorable banding pattern, which were further used in this study. Three primer combinations E-TA / M-CTT (IRRI-NPT), E-AG / M-CAC (Tulasi) and E-AA / M-CAG (IR 68899B) produced only monomorphic bands in all the transgenic and control rice plants .A percentage of 0.61% of 430 million bases of haploid rice genome were examined by the use of 11 AFLP primer combinations employed in this study. The DNA fingerprints generated by AFLP analysis, of each Bt rice population was compared with their respective non-transgenic control and was found to be > 97% similar. This indicated that the introduction of Bt gene into the genome of six rice varieties showed few genomic changes. The comparison shows that fewer changes were observed among the transgenic plants developed by Agrobacterium infection than that of developed through particle bombardment. Transgene integration pattern and their copy number were associated with the extent of genomic changes observed in the transgenic Bt rice varieties. AFLP fingerprints of the six transgenic rice varieties evidenced few, but consistent polymorphic bands between the transgenic individuals with different PI values. Relationships among the transgenic populations with their control rice plants were expressed in the form of dendrograms. PMID:21844690

Chandel, Girish; Datta, Karabi; Datta, Swapan K

2010-01-01

268

Transgenic Tobacco Overexpressing Tea cDNA Encoding Dihydroflavonol 4-Reductase and Anthocyanidin Reductase Induces Early Flowering and Provides Biotic Stress Tolerance  

PubMed Central

Flavan-3-ols contribute significantly to flavonoid content of tea (Camellia sinensis L.). Dihydroflavonol 4-reductase (DFR) and anthocyanidin reductase (ANR) are known to be key regulatory enzymes of flavan-3-ols biosynthesis. In this study, we have generated the transgenic tobacco overexpressing individually tea cDNA CsDFR and CsANR encoding for DFR and ANR to evaluate their influence on developmental and protective abilities of plant against biotic stress. The transgenic lines of CsDFR and CsANR produced early flowering and better seed yield. Both types of transgenic tobacco showed higher content of flavonoids than control. Flavan-3-ols such as catechin, epicatechin and epicatechingallate were found to be increased in transgenic lines. The free radical scavenging activity of CsDFR and CsANR transgenic lines was improved. Oxidative stress was observed to induce lesser cell death in transgenic lines compared to control tobacco plants. Transgenic tobacco overexpressing CsDFR and CsANR also showed resistance against infestation by a tobacco leaf cutworm Spodoptera litura. Results suggested that the overexpression of CsDFR and CsANR cDNA in tobacco has improved flavonoids content and antioxidant potential. These attributes in transgenic tobacco have ultimately improved their growth and development, and biotic stress tolerance. PMID:23823500

Kumar, Vinay; Nadda, Gireesh; Kumar, Sanjay; Yadav, Sudesh Kumar

2013-01-01

269

Expression of Interleukin4 in the Epidermis of Transgenic Mice Results in a Pruritic Inflammatory Skin Disease: An Experimental Animal Model to Study Atopic Dermatitis  

Microsoft Academic Search

Atopic dermatitis, a common, chronic, inflammatory skin disease that occurs with increasing prevalence, is characterized by hyperactivated cytokines of helper T cell subset 2 and is frequently associated with staphylococcal infection. An experimental animal model of atopic dermatitis induced by transgenically introduced cytokine is not available. We generated a transgenic mouse line expressing epidermal interleukin-4, a critical cytokine of helper

Lawrence S. Chan; Neha Robinson; Luting Xu

2001-01-01

270

Acetylcholinesterase-Positive Fiber Deafferentation and Cell Shrinkage in the Septohippocampal Pathway of Aged Amyloid Precursor Protein London Mutant Transgenic Mice  

Microsoft Academic Search

Several lines of evidence implicate a cholinergic deficit in Alzheimer's disease (AD). Transgenic mice that overexpress clinical mutants of the human amyloid precursor protein (APP) have been generated that recapitulate many aspects of AD. We now analyzed the cholinergic system in aged APP\\/London transgenic mice. The major finding was the reorganization of acetylcholinesterase-positive fibers within the hippocampus and the reduced

Francisca C. Bronfman; Dieder Moechars; Fred Van Leuven

2000-01-01

271

Endoscopic and surgical resection of T1a/T1b esophageal neoplasms: A systematic review  

PubMed Central

AIM: To investigate potential therapeutic recommendations for endoscopic and surgical resection of T1a/T1b esophageal neoplasms. METHODS: A thorough search of electronic databases MEDLINE, Embase, Pubmed and Cochrane Library, from 1997 up to January 2011 was performed. An analysis was carried out, pooling the effects of outcomes of 4241 patients enrolled in 80 retrospective studies. For comparisons across studies, each reporting on only one endoscopic method, we used a random effects meta-regression of the log-odds of the outcome of treatment in each study. “Neural networks” as a data mining technique was employed in order to establish a prediction model of lymph node status in superficial submucosal esophageal carcinoma. Another data mining technique, the “feature selection and root cause analysis”, was used to identify the most important predictors of local recurrence and metachronous cancer development in endoscopically resected patients, and lymph node positivity in squamous carcinoma (SCC) and adenocarcinoma (ADC) separately in surgically resected patients. RESULTS: Endoscopically resected patients: Low grade dysplasia was observed in 4% of patients, high grade dysplasia in 14.6%, carcinoma in situ in 19%, mucosal cancer in 54%, and submucosal cancer in 16% of patients. There were no significant differences between endoscopic mucosal resection and endoscopic submucosal dissection (ESD) for the following parameters: complications, patients submitted to surgery, positive margins, lymph node positivity, local recurrence and metachronous cancer. With regard to piecemeal resection, ESD performed better since the number of cases was significantly less [coefficient: -7.709438, 95%CI: (-11.03803, -4.380844), P < 0.001]; hence local recurrence rates were significantly lower [coefficient: -4.033528, 95%CI: (-6.151498, -1.915559), P < 0.01]. A higher rate of esophageal stenosis was observed following ESD [coefficient: 7.322266, 95%CI: (3.810146, 10.83439), P < 0.001]. A significantly greater number of SCC patients were submitted to surgery (log-odds, ADC: -2.1206 ± 0.6249 vs SCC: 4.1356 ± 0.4038, P < 0.05). The odds for re-classification of tumor stage after endoscopic resection were 53% and 39% for ADC and SCC, respectively. Local tumor recurrence was best predicted by grade 3 differentiation and piecemeal resection, metachronous cancer development by the carcinoma in situ component, and lymph node positivity by lymphovascular invasion. With regard to surgically resected patients: Significant differences in patients with positive lymph nodes were observed between ADC and SCC [coefficient: 1.889569, 95%CI: (0.3945146, 3.384624), P < 0.01). In contrast, lymphovascular and microvascular invasion and grade 3 patients between histologic types were comparable, the respective rank order of the predictors of lymph node positivity was: Grade 3, lymphovascular invasion (L+), microvascular invasion (V+), submucosal (Sm) 3 invasion, Sm2 invasion and Sm1 invasion. Histologic type (ADC/SCC) was not included in the model. The best predictors for SCC lymph node positivity were Sm3 invasion and (V+). For ADC, the most important predictor was (L+). CONCLUSION: Local tumor recurrence is predicted by grade 3, metachronous cancer by the carcinoma in-situ component, and lymph node positivity by L+. T1b cancer should be treated with surgical resection. PMID:23539431

Sgourakis, George; Gockel, Ines; Lang, Hauke

2013-01-01

272

Decreased shoot stature and grain  -amylase activity following ectopic expression of a gibberellin 2-oxidase gene in transgenic wheat  

Microsoft Academic Search

Ectopic expression of a gibberellin 2-oxidase gene (PcGA2ox1) decreased the content of bioactive gibber- ellins (GAs) in transgenic wheat, producing a range of dwarf plants with different degrees of severity. In at least one case, a single transformation event gave rise to T1 plants with different degrees of dwarfism, the pheno- types being stably inherited over at least four genera-

Nigel E. J. Appleford; Mark D. Wilkinson; Qian Ma; Daniel J. Evans; Marlon C. Stone; Stephen P. Pearce; Stephen J. Powers; Stephen G. Thomas; Huw D. Jones; Andrew L. Phillips; Peter Hedden; John R. Lenton

2007-01-01

273

Microarray analyses reveal that plant mutagenesis may induce more transcriptomic changes than transgene insertion  

PubMed Central

Controversy regarding genetically modified (GM) plants and their potential impact on human health contrasts with the tacit acceptance of other plants that were also modified, but not considered as GM products (e.g., varieties raised through conventional breeding such as mutagenesis). What is beyond the phenotype of these improved plants? Should mutagenized plants be treated differently from transgenics? We have evaluated the extent of transcriptome modification occurring during rice improvement through transgenesis versus mutation breeding. We used oligonucleotide microarrays to analyze gene expression in four different pools of four types of rice plants and respective controls: (i) a ?-irradiated stable mutant, (ii) the M1 generation of a 100-Gy ?-irradiated plant, (iii) a stable transgenic plant obtained for production of an anticancer antibody, and (iv) the T1 generation of a transgenic plant produced aiming for abiotic stress improvement, and all of the unmodified original genotypes as controls. We found that the improvement of a plant variety through the acquisition of a new desired trait, using either mutagenesis or transgenesis, may cause stress and thus lead to an altered expression of untargeted genes. In all of the cases studied, the observed alteration was more extensive in mutagenized than in transgenic plants. We propose that the safety assessment of improved plant varieties should be carried out on a case-by-case basis and not simply restricted to foods obtained through genetic engineering. PMID:18303117

Batista, Rita; Saibo, Nelson; Lourenco, Tiago; Oliveira, Maria Margarida

2008-01-01

274

A novel transgenic chimaeric mouse system for the rapid functional evaluation of genes encoding secreted proteins  

PubMed Central

A major challenge of the post-genomic era is the functional characterization of anonymous open reading frames (ORFs) identified by the Human Genome Project. In this context, there is a strong requirement for the development of technologies that enhance our ability to analyze gene functions at the level of the whole organism. Here, we describe a rapid and efficient procedure to generate transgenic chimaeric mice that continuously secrete a foreign protein into the systemic circulation. The transgene units were inserted into the genomic site adjacent to the endogenous immunoglobulin (Ig) ? locus by homologous recombination, using a modified mouse embryonic stem (ES) cell line that exhibits a high frequency of homologous recombination at the Ig? region. The resultant ES clones were injected into embryos derived from a B-cell-deficient host strain, thus producing chimaerism-independent, B-cell-specific transgene expression. This feature of the system eliminates the time-consuming breeding typically implemented in standard transgenic strategies and allows for evaluating the effect of ectopic transgene expression directly in the resulting chimaeric mice. To demonstrate the utility of this system we showed high-level protein expression in the sera and severe phenotypes in human EPO (hEPO) and murine thrombopoietin (mTPO) transgenic chimaeras. PMID:15914664

Kakitani, Makoto; Oshima, Takeshi; Horikoshi, Kaori; Yoshitome, Tetsuo; Ueda, Akiko; Kajikawa, Miwa; Iba, Yumi; Ozone, Yoshinao; Ijima, Yuki; Yoshino, Tohko; Itoh, Mikiko; Seki, Sachiko; Aoki, Ayako; Ishihara, Toshie; Shionoya, Michiyo; Makino, Utako; Kitada, Rina; Ohguma, Atsuko; Ohta, Takami; Yoshida, Yoshimasa; Kudoh, Hiroe; Hanaoka, Kazunori; Sibuya, Kazunori; Ishida, Isao; Kakeda, Minoru; Yagi, Mikio; Yoneya, Takashi; Tomizuka, Kazuma

2005-01-01

275

Early temporal short-term memory deficits in double transgenic APP/PS1 mice.  

PubMed

We tested single APP (Tg2576) transgenic, PS1 (PS1dE9) transgenic, and double APP/PS1 transgenic mice at 3 and 6 months of age on the acquisition of a hippocampal-dependent operant "differential reinforcement of low rate schedule" (DRL) paradigm. In this task mice are required to wait for at least 10 seconds (DRL-10s) between 2 consecutive nose poke responses. Our data showed that while single APP and PS1 transgene expression did not affect DRL learning and performance, mice expressing double APP/PS1 transgenes were impaired in the acquisition of DRL-10s at 6 months, but not at 3 months of age. The same impaired double transgenic mice, however, were perfectly capable of normal acquisition of signaled DRL-10s (SDRL-10s) task, a hippocampal-independent task, wherein mice were required to emit responses when the end of the 10-second delay was signaled by a lighting of the chamber. The age-dependent and early deficits of APP/PS1 mice suggest that the appetitive DRL paradigm is sensitive to the amyloid pathology present in double APP/PS1 mice, and that this mouse line represents a good model with which to study the efficacy of therapeutic strategies against Alzheimer's disease. PMID:20817351

Lagadec, Saioa; Rotureau, Lolita; Hémar, Agnès; Macrez, Nathalie; Delcasso, Sebastien; Jeantet, Yannick; Cho, Yoon H

2012-01-01

276

Tol2-mediated generation of a transgenic haplochromine cichlid, Astatotilapia burtoni.  

PubMed

Cichlid fishes represent one of the most species-rich and rapid radiations of a vertebrate family. These ~2200 species, predominantly found in the East African Great Lakes, exhibit dramatic differences in anatomy, physiology, and behavior. However, the genetic bases for this radiation, and for the control of their divergent traits, are unknown. A flood of genomic and transcriptomic data promises to suggest mechanisms underlying the diversity, but transgenic technology will be needed to rigorously test the hypotheses generated. Here we demonstrate the successful use of the Tol2 transposon system to generate transgenic Astatotilapia burtoni, a haplochromine cichlid from Lake Tanganyika, carrying the GFP transgene under the control of the ubiquitous EF1? promoter. The transgene integrates into the genome, is successfully passed through the germline, and the widespread GFP expression pattern is stable across siblings and multiple generations. The stable inheritance and expression patterns indicate that the Tol2 system can be applied to generate A. burtoni transgenic lines. Transgenesis has proven to be a powerful technology for manipulating genes and cells in other model organisms and we anticipate that transgenic A. burtoni and other cichlids will be used to test the mechanisms underlying behavior and speciation. PMID:24204902

Juntti, Scott A; Hu, Caroline K; Fernald, Russell D

2013-01-01

277

Expression of hemagglutinin protein of Rinderpest virus in transgenic pigeon pea [Cajanus cajan (L.) Millsp.] plants.  

PubMed

Rinderpest virus is the causative agent of a devastating, often fatal disease in wild and domestic bovids that is endemic in Africa, the Middle East and South Asia. The existing live attenuated vaccine is heat-labile, and thus there is a need for the development of new strategies for vaccination. This paper reports the development of transgenic pigeon pea [ Cajanus cajun (L.) Millsp.] expressing one of the protective antigens, the hemagglutinin (H) protein of Rinderpest virus. A 2-kb fragment containing the coding region of the H protein was cloned into pBI121 and mobilized into Agrobacterium tumefaciensstrain EHA105. Embryonic axes and cotyledonary nodes from germinated seeds of pigeon pea were used for transformation. The presence of the transgene in transgenic plants was confirmed by Southern blots, and the specific transcription of the marker gene in the plants was demonstrated by reverse transcription-polymerase chain reaction. Integration of the H gene into the pigeon pea genome was confirmed by Southern hybridization. The expression of the H protein in the transgenic lines was confirmed by Western blot analysis using a polyclonal monospecific antibody to the H protein. The highest level of expression of the hemagglutinin protein in leaves of pigeon pea was 0.49% of the total soluble protein. The transgenic plants were fertile and the transgene expressed in the progeny. PMID:12789415

Satyavathi, V V; Prasad, V; Khandelwal, Abha; Shaila, M S; Sita, G Lakshmi

2003-03-01

278

Green fluorescent protein transgene driven by Kit regulatory sequences is expressed in hematopoietic stem cells  

PubMed Central

Background The transcriptional regulation of stem cell genes is still poorly understood. Kit, encoding the stem cell factor receptor, is a pivotal molecule for multiple types of stem/progenitor cells. We previously generated mouse lines expressing transgenic green fluorescent protein under the control of Kit promoter/first intron regulatory elements, and we demonstrated expression in hematopoietic progenitors. Design and Methods In the present work we investigated whether the transgene is also expressed in hematopoietic stem cells of adult bone marrow and fetal liver. To this purpose, we tested, in long-term repopulating assays, cell fractions expressing different levels of green fluorescent protein within Kit-positive or SLAM-selected populations. Results The experiments demonstrated transgene expression in both fetal and adult hematopoietic stem cells and indicated that the transgene is transcribed at distinctly lower levels in hematopoietic stem cells than in pluripotent and committed progenitors. Conclusions These results, together with previous data, show that a limited subset of DNA sequences drives gene expression in number of stem cell types (hematopoietic stem cells, primordial germ cells, cardiac stem cells). Additionally, our results might help to further improve high level purification of hematopoietic stem cells for experimental purposes. Finally, as the Kit/green fluorescent protein transgene is expressed in multiple stem cell types, our transgenic model provides powerful in vivo system to track these cells during development and tissue regeneration. PMID:19181779

Cerisoli, Francesco; Cassinelli, Letizia; Lamorte, Giuseppe; Citterio, Stefania; Bertolotti, Francesca; Magli, Maria Cristina; Ottolenghi, Sergio

2009-01-01

279

Transgenic Brassica juncea plants expressing MsrA1, a synthetic cationic antimicrobial peptide, exhibit resistance to fungal phytopathogens.  

PubMed

Cationic antimicrobial peptides (CAPs) have shown potential against broad spectrum of phytopathogens. Synthetic versions with desirable properties have been modeled on these natural peptides. MsrA1 is a synthetic chimera of cecropin A and melittin CAPs with antimicrobial properties. We generated transgenic Brassica juncea plants expressing the msrA1 gene aimed at conferring fungal resistance. Five independent transgenic lines were evaluated for resistance to Alternaria brassicae and Sclerotinia sclerotiorum, two of the most devastating pathogens of B. juncea crops. In vitro assays showed inhibition by MsrA1 of Alternaria hyphae growth by 44-62 %. As assessed by the number and size of lesions and time taken for complete leaf necrosis, the Alternaria infection was delayed and restricted in the transgenic plants with the protection varying from 69 to 85 % in different transgenic lines. In case of S. sclerotiorum infection, the lesions were more severe and spread profusely in untransformed control compared with transgenic plants. The sclerotia formed in the stem of untransformed control plants were significantly more in number and larger in size than those present in the transgenic plants where disease protection of 56-71.5 % was obtained. We discuss the potential of engineering broad spectrum biotic stress tolerance by transgenic expression of CAPs in crop plants. PMID:24452332

Rustagi, Anjana; Kumar, Deepak; Shekhar, Shashi; Yusuf, Mohd Aslam; Misra, Santosh; Sarin, Neera Bhalla

2014-06-01

280

Characterization of transgenic tobacco plants containing bacterial bphC gene and study of their phytoremediation ability.  

PubMed

Genetically modified plants can serve as an efficient tool for remediation of diverse dangerous pollutants of the environment such as pesticides, heavy metals, explosives and persistent organic compounds. Transgenic lines of Nicotiana tabacum containing bacterial bphC gene from the degradation pathway of polychlorinated biphenyls (PCBs) were tested. The product of the bphC gene - enzyme 2,3-dihydroxybiphenyl-1,2-dioxygenase is responsible for cleaving of the biphenyl ring. The presence of bphC gene in transgenic plants was detected on DNA, RNA and protein level. The expression of the bphC/His gene was verified afterpurification of the enzyme from plants by affinity chromatography followed by a Western blot and immunochemical assay. The enzyme activity of isolated protein was detected. Efficient transformation of 2,3-DHB by transgenic plants was achieved and the lines also exhibited high production of biomass. The transgenic plants were more tolerant to the commercial PCBs mixture Delor 103 than non-transgenic tobacco. And finally, the higher decrease of total PCB content and especially congener 28 in real contaminated soil from a dumpsite was determined after cultivation of transgenic plant in comparison with nontransgenic tobacco. The substrate specificity of transgenic plants was the same as substrate specificity of BphC enzyme. PMID:24933894

Viktorovtá, Jitka; Novakova, Martina; Trbolova, Ladislava; Vrchotova, Blanka; Lovecka, Petra; Mackova, Martina; Macek, Tomas

2014-01-01

281

Safety and Public Acceptance of Transgenic Products  

Microsoft Academic Search

Public acceptance of transgenic (genetically engineered, GE) prod- ucts is influenced by the perception of direct or indirect risks and benefits and the credibility of regulatory agencies that evaluate food and environmental safety. In North America acceptance of GE foods is holding steady, while knowledge about them remains low. Develop- ment of transgenic foods with improved nutritional properties or other

Patrick F. Byrne

2006-01-01

282

Chicken Embryonic Stem Cells and Transgenic Strategies  

Microsoft Academic Search

The production of transgenic birds is an important goal for both fundamental and applied biology. Different methods have been employed to generate transgenic chickens, including microinjection, use of retroviruses and transfection of primordial germ or embryonic germ cells. In this review we will briefly describe these techniques and our efforts to obtain genetically modified avian embryonic stem (ES) cells using

B. Pain; P. Chenevier; J. Samarut

1999-01-01

283

Iridium 192 implantation of T1 and T2 carcinomas of the mobile tongue  

Microsoft Academic Search

Between 1970 and 1986, 166 patients with T1 or T2 epidermoid carcinomas of the mobile tongue were treated by iridium 192 implantation (70 T1N0, 83 T2N0, 13 T1-2 N1-3). Five-year actuarial survival was 52% for T1N0, 44% for T2aN0, and 8% for or T1-2 N1-3. Cause specific survivals were 90%, 71%, and 46%, respectively. Local control was 87% for both

J. J. Mazeron; J. M. Crook; V. Benck; G. Marinello; M. Martin; M. Raynal; E. Haddad; R. Peynegre; J. P. Le Bourgeois; W. Walop

1990-01-01

284

Public perceptions of transgenic animals.  

PubMed

The field of animal biotechnology has been rapidly expanding and the development of transgenic animals has been part of this research expansion. How the public perceives such developments is an important component of policy considerations. In general, biotechnology applications have been judged with evident hierarchies of acceptability. There appearto be hierarchies in terms of the type of organism being modified, the purpose of the application, the means to attain particular ends, and the nature of the benefits obtained. While general awareness of biotechnology and its specific applications remains low to moderate, this article presents data regarding public acceptance of a variety of applications. These range from the use of animals as disease models and as sources for tissues and organs, to the use of transgenic animals for disease control, for food, and for the production of pharmaceutical and industrial products. Case-by-case judgments are evident, but at the same time, the application of criteria such as the nature of the organism being modified, the animal welfare aspects and the ethical-moral concerns are additional criteria for public judgments. These findings are discussed in the context of their implications for public policy. PMID:16110885

Einsiedel, E F

2005-04-01

285

Transgenic approach to improve wheat ( Triticum aestivum L.) nutritional quality  

Microsoft Academic Search

An amaranth (Amaranthus hypochondriacus) albumin gene, encoding the 35-kDa AmA1 protein of the seed, with a high content of essential amino acids, was used in the\\u000a biolistic transformation of bread wheat (Triticum aestivum L.) variety Cadenza. The transformation cassette carried the ama1 gene under the control of a powerful wheat endosperm-specific promoter (1Bx17 HMW-GS). Southern-blot analysis of T1 lines confirmed

Cecília Tamás; Boglárka N. Kisgyörgy; Mariann Rakszegi; Mark D. Wilkinson; Moon-Sik Yang; László Láng; László Tamás; Zoltán Bed?

2009-01-01

286

Up-Regulation of 1-Deoxy-d-Xylulose-5-Phosphate Synthase Enhances Production of Essential Oils in Transgenic Spike Lavender1  

PubMed Central

Spike lavender (Lavandula latifolia) is an aromatic shrub cultivated worldwide for the production of essential oils. The major constituents of these oils are monoterpenes, which are obtained from isopentenyl diphosphate and dimethylallyl diphosphate precursors through the plastidial methylerythritol phosphate (MEP) pathway and/or the cytosolic mevalonate pathway. 1-Deoxy-d-xylulose-5-P synthase (DXS) catalyzes the first step of the MEP pathway. A cDNA coding for the Arabidopsis (Arabidopsis thaliana) DXS was constitutively expressed in spike lavender. Gas chromatography/mass spectrometry analyses revealed that transgenic plants accumulated significantly more essential oils compared to controls (from 101.5% to 359.0% and from 12.2% to 74.1% yield increase compared to controls in leaves and flowers, respectively). T0 transgenic plants were grown for 2 years, self-pollinated, and the T1 seeds obtained. The inheritance of the DXS transgene was studied in the T1 generation. The increased essential oil phenotype observed in the transgenic T0 plants was maintained in the progeny that inherited the DXS transgene. Total chlorophyll and carotenoid content in DXS progenies that inherited the transgene depended on the analyzed plant, showing either no variation or a significant decrease in respect to their counterparts without the transgene. Transgenic plants had a visual phenotype similar to untransformed plants (controls) in terms of morphology, growth habit, flowering, and seed germination. Our results demonstrate that the MEP pathway contributes to essential oil production in spike lavender. They also demonstrate that the DXS enzyme plays a crucial role in monoterpene precursor biosynthesis and, thus, in essential oil production in spike lavender. In addition, our results provide a strategy to increase the essential oil production in spike lavender by metabolic engineering of the MEP pathway without apparent detrimental effects on plant development and fitness. PMID:16980564

Munoz-Bertomeu, Jesus; Arrillaga, Isabel; Ros, Roc; Segura, Juan

2006-01-01

287

Transgenes and their contributions to epigenetic research.  

PubMed

Shortly after gene transfer technologies had been established for different plant species, the first reports emerged about transgenes showing unexpected segregation patterns due to unstable expression. Initially, the erratic expression behavior of transgenes was considered a nuisance that impeded the impact and efficiency of a new technology. With the investigation of transgene silencing effects, however, it soon became clear that transgenes had helped us in a rather unexpected way to identify novel molecular pathways that were highly relevant to plant development and evolution. This article gives an account of a journey that started with the analysis of transgene-related silencing events and that led to the discovery of a new molecular world of small RNAs and epigenetic marks that regulate plant gene expression and adaptation to environmental changes. PMID:24166433

Meyer, Peter

2013-01-01

288

Enhancing the scopolamine production in transgenic plants of Atropa belladonna by overexpressing pmt and h6h genes.  

PubMed

Atropa belladonna is officially deemed as the commercial plant to produce scopolamine in China. In this study we report the simultaneous overexpression of two functional genes involved in biosynthesis of scopolamine, which encode the upstream key enzyme putrescine N-methyltransferase (PMT) and the downstream key enzyme hyoscyamine 6?-hydroxylase (H6H), respectively, in transgenic herbal plants Atropa belladonna. Analysis of gene expression profile indicated that both pmt and h6h were expressed at a higher level in transgenic lines, which would be favorable for biosynthesis of scopolamine. High-performance liquid chromatography result suggested that transgenic lines could produce higher accumulation of scopolamine at different levels compared with wild-type lines. Scopolamine content increased to 7.3-fold in transgenic line D9 compared with control lines. This study not only confirms that co-overexpression of pmt and h6h is an ideal method to improve the biosynthetic capacity of scopolamine but also successfully cultivates the transgenic line D9, which significantly enhanced the scopolamine accumulation. Our research can serve as an alternative choice to provide scopolamine resources for relative industry, which is more competitive than conventional market. PMID:21883248

Wang, Xirong; Chen, Min; Yang, Chunxian; Liu, Xiaoqiang; Zhang, Lei; Lan, Xiaozhong; Tang, Kexuan; Liao, Zhihua

2011-12-01

289

Characterization of resistance mechanism in transgenic Nicotiana benthamiana containing Turnip crinkle virus coat protein.  

PubMed

Two transgenic lines, of Nicotiana benthamiana expressing Turnip crinkle virus (TCV)-coat protein (CP) gene with contrasting phenotype, the highest (#3) and the lowest (#18) CP expressers, were selected and challenged with the homologous TCV. The former, the highest expresser, showed nearly five times more CP expression than the latter. Progenies of #3 and #18 lines showed 30 and 100% infection rates, respectively. The infected progenies of #3 line showed mild and delayed symptom with TCV. This is a coat protein-mediated resistance (CP-MR), and its resistance level is directly proportional to CP transgene expression. However, CP-MR of the transgenic plants was specific only for TCV but not for heterologous viruses. Newly growing leaves of those infected progenies of #3 line did not show any visible symptoms at 4-week post-inoculation (wpi) with TCV, suggesting a reversal from infection. This was confirmed by RT-PCR analysis with the disappearance of the target at 4 wpi. This is a case of RNA-mediated resistance, and a threshold level of transgene expression may be needed to achieve the silent state. To confirm the RNA silencing, we infiltrated Agrobacterium carrying TCV-CP into leaves of progenies of #3 and performed RT-PCR analysis. The results indicate that TCV-CP's suppressor activity against RNA silencing itself can be silenced by the homologous expression of TCV-CP in the transgenic plants. The transgenic plants containing TCV-CP seem to be a model system to study viral protection mediated by a combination of protein and RNA silencing. PMID:18704429

Vasudevan, Ayyappan; Oh, Tae-Kyun; Park, Jae Sung; Lakshmi, Sumitra Vijayachandran; Choi, Bong Kum; Kim, Sue Hoon; Lee, Hyun Ju; Ji, Jing; Kim, Joo-Hwan; Ganapathi, Andy; Kim, Sei Chang; Choi, Chang Won

2008-11-01

290

Field performance of transgenic sugarcane expressing isomaltulose synthase.  

PubMed

Transgenic sugarcane plants expressing a vacuole-targeted isomaltulose (IM) synthase in seven recipient genotypes (elite cultivars) were evaluated over 3?years at a field site typical of commercial cane growing conditions in the Burdekin district of Australia. IM concentration typically increased with internode maturity and comprised up to 217?mm (33% of total sugars) in whole-cane juice. There was generally a comparable decrease in sucrose concentration, with no overall decrease in total sugars. Sugarcane is vegetatively propagated from stem cuttings known as setts. Culture-derived plants were slower to establish and generally gave shorter and thinner stalks at harvest than those grown from field-sourced setts in the initial field generations. However, after several cycles of field propagation, selections were obtained with cane yields similar to the recipient genotypes. There was no apparent adverse effect of IM accumulation on vigour assessed by stalk height and diameter or other visual indicators including germination of setts and establishment of stools. There was some inconsistency in IM levels in juice, between samplings of the vegetatively propagated transgenic lines. Until the causes are resolved, it is prudent to selectively propagate from stalks with higher IM levels in the initial vegetative field generations. Pol/Brix ratio allowed rapid identification of lines with high IM levels, using common sugar industry instruments. Sucrose isomerase activity was low in these transgenic lines, and the results indicate strong potential to develop sugarcane for commercial-scale production of IM if higher activity can be engineered in appropriate developmental patterns. PMID:21895946

Basnayake, Shiromani W V; Morgan, Terrance C; Wu, Luguang; Birch, Robert G

2012-02-01

291

ARTHROPOD MANAGEMENT AND APPLIED ECOLOGY Heliothine Larval Behavior on Transgenic Cotton Expressing a Bacillus thuringiensis Insecticidal Exotoxin, Vip3A  

Microsoft Academic Search

Field studies were performed during 2005 and 2006 to determine bollworm, Helicoverpa zea (Boddie), and tobacco budworm, Heliothis virescens (F.), larval behavior on conventional non-transgenic cotton plants (Coker 312), and on transgenic Bacillus thuringiensis Berliner (Bt) plants expressing the Vip3A protein or a com- bination of Vip3A + Cry 1Ab proteins (VipCot). Plants representing each of the three cotton lines

P. L. Bommireddy; B. R. Leonard; K. Emfinger

292

Production of germline transgenic chickens expressing enhanced green fluorescent protein using a MoMLV-based retrovirus vector  

Microsoft Academic Search

The Moloney murine leukemia virus (MoMLV) -based retrovirus vector system has been used most often in gene transfer work, but has been known to cause silencing of the imported gene in transgenic animals. In the present study, using a MoMLV-based retrovirus vector, we successfully gener- ated a new transgenic chicken line expressing high levels of enhanced green fluorescent protein (eGFP).

Bon Chul Koo; Mo Sun Kwon; Bok Ryul Choi; Jin-Hoi Kim; Seong-Keun Cho; Sea Hwan Sohn; Eun Jung Cho; Hoon Taek Lee; Wonkyung Chang; Iksoo Jeon; Jin-Ki Park; Jae Bok Park; Teoan Kim

2006-01-01

293

Enhanced polyhydroxybutyrate production in transgenic sugarcane.  

PubMed

Polyhydroxybutyrate (PHB) is a bacterial polyester that has properties similar to some petrochemically produced plastics. Plant-based production has the potential to make this biorenewable plastic highly competitive with petrochemical-based plastics. We previously reported that transgenic sugarcane produced PHB at levels as high as 1.8% leaf dry weight without penalty to biomass accumulation, suggesting scope for improving PHB production in this species. In this study, we used different plant and viral promoters, in combination with multigene or single-gene constructs to increase PHB levels. Promoters tested included the maize and rice polyubiquitin promoters, the maize chlorophyll A/B-binding protein promoter and a Cavendish banana streak badnavirus promoter. At the seedling stage, the highest levels of polymer were produced in sugarcane plants when the Cavendish banana streak badnavirus promoter was used. However, in all cases, this promoter underwent silencing as the plants matured. The rice Ubi promoter enabled the production of PHB at levels similar to the maize Ubi promoter. The maize chlorophyll A/B-binding protein promoter enabled the production of PHB to levels as high as 4.8% of the leaf dry weight, which is approximately 2.5 times higher than previously reported levels in sugarcane. This is the first time that this promoter has been tested in sugarcane. The highest PHB-producing lines showed phenotypic differences to the wild-type parent, including reduced biomass and slight chlorosis. PMID:22369516

Petrasovits, Lars A; Zhao, Lihan; McQualter, Richard B; Snell, Kristi D; Somleva, Maria N; Patterson, Nii A; Nielsen, Lars K; Brumbley, Stevens M

2012-06-01

294

[Obtainment of transgenic wheat with the insecticidal lectin from snowdrop (Galanthus nivalis agglutinin; GNA) gene and analysis of resistance to aphid].  

PubMed

Snowdrop lectin (Galanthus nivalis agglutinin; GNA) is toxic to sap sucking injurious insects of Homopteran. A new gna gene has been transferred into common spring wheat Zhong60634 and winter wheat Yumai66 with high yield by using the biolistic transformation method. Transgenic wheat plants have been obtained in both of the two varieties. Two transgenic plants (T0) have been obtained from the bombarded 535 immature embryos of Zhong60634. Bioassay results show that the development of aphid could be slowed down and the survival rate of young aphid could be reduced by gna gene. Seventeen transgenic plants (T0) were obtained from the bombarded 4636 immature embryos of Yumai66. Twenty plantlets with good resistance to Rhopalosiphum padi and Macrosiphum avenae, which are mainly aphid in north wheat area, were identified from the transgenic plants of T1 generation that came from 8 T0 transgenic plants with good resistance to aphid. The anti-aphid bioassay shows that resistance to the different grain aphid is not the same in transgenic wheat plants. To Rhopalosiphum padi, the rate of survival aphid 8 days after exposing transgenic plants to aphids is significantly lower than that of nontransgenic plants. To Macrosiphum avenae, growth speed of aphids is slowed down but not killed. At the same time, the death rate of young aphids is increased. Anyway, feeding of the two kinds of aphids has been controlled in a certain degree by gna gene when aphids can free to move in plants. PMID:15473311

Liang, Hui; Zhu, Yin-Feng; Zhu, Zhen; Sun, Dong-Fa; Jia, Xu

2004-02-01

295

Optimized and combined T1 and B1 mapping technique for fast and accurate T1 quantification in contrast-enhanced abdominal MRI.  

PubMed

Fast T(1) mapping techniques are a valuable means of quantitatively assessing the distribution and dynamics of intravenously or orally applied paramagnetic contrast agents (CAs) by noninvasive imaging. In this study a fast T(1) mapping technique based on the variable flip angle (VFA) approach was optimized for accurate T(1) quantification in abdominal contrast-enhanced (CE) MRI. Optimization methods were developed to maximize the signal-to-noise ratio (SNR) and ensure effective RF and gradient spoiling, as well as a steady state, for a defined T(1) range of 100-800 ms and a limited acquisition time. We corrected B(1) field inhomogeneities by performing an additional measurement using an optimized fast B(1) mapping technique. High-precision in vitro and abdominal in vivo T(1) maps were successfully generated at a voxel size of 2.8 x 2.8 x 15 mm(3) and a temporal resolution of 2.3 s per T(1) map on 1.5T and 3T MRI systems. The application of the proposed fast T(1) mapping technique in abdominal CE-MRI enables noninvasive quantification of abdominal tissue perfusion and vascular permeability, and offers the possibility of quantitatively assessing dilution, distribution, and mixing processes of labeled solutions or drugs in the gastrointestinal tract. PMID:17326175

Treier, Reto; Steingoetter, Andreas; Fried, Michael; Schwizer, Werner; Boesiger, Peter

2007-03-01

296

TRANSFECTION OF A RAT CYTOCHROME P-450B CDNA INTO C3H10T1/2CL8 MOUSE EMBRYO FIBROBLASTS  

EPA Science Inventory

A cDNA clone of a rat cytochrome P450b gene was used to construct an expression vector driven by an SV40 promoter and containing a G418-resistance selectable marker. his bifunctional plasmid (pJRSL100) was transfected into the C3H10T1/2CL8 mouse embryo fibroblast cell line. 418-r...

297

Session T1A 978-1-4244-1970-8/08/$25.00 2008 IEEE October 22 25, 2008, Saratoga Springs, NY  

E-print Network

ASEE/IEEE Frontiers in Education Conference T1A-1 Work in Progress - Combined Introduction of C of stack frame. An online lab manual has been developed for this course that is freely available traditional command-line tools including bash, gcc, as, ld, and make. The reformed course's outcomes

Freudenthal, Eric

298

Expression of the Huntington's disease transgene in neural stem cell cultures from R6/2 transgenic mice.  

PubMed

Huntington's disease (HD) is an inherited neurodegenerative disorder resulting in neuronal cell death in discrete brain regions due to an expanded CAG repeat of the huntingtin gene. The transgenic mouse model R6/2 expresses exon 1 of the human huntingtin gene with >150 CAG repeats, which produces mutant HD protein with an expanded poly-glutamine tract. We have established a neuronal stem cell system deriving from transgenic HD R6/2 neonatal brains as a renewable source for neurons and glia to facilitate studies of HD neuropathology and therapies. These R6/2 stem cell cultures can be cryopreserved and revived. Thawed neural progenitors can be expanded, established as continuous cell lines, and induced to differentiate into glia and neurons. Using standard culture conditions, there was no detectable morphological difference between wild type and HDR6/2 cells. Western analysis reveals that R6/2, but not wild type neurospheres, express the expanded repeat transgenic protein. Immunocytochemistry reveals that at a higher antibody concentration, huntingtin can be localized in the nucleus and the cytoplasm of wild type and R6/2 cells. We conclude that the R6/2 neuronal stem cell culture is a valuable tool for investigating HD pathogenesis and potential genetic or pharmacological interventions. PMID:11719265

Chu-LaGraff, Q; Kang, X; Messer, A

299

Generation and characterization of ScxCre transgenic mice.  

PubMed

Scleraxis (Scx) is a basic helix-loop-helix transcription factor that is a marker for the tendon/ligament cell lineage. The ?11 kb genomic region from the mouse Scx gene locus faithfully recapitulates the endogenous Scx expression pattern in ScxGFP transgenic (Tg) mice. We have established two Tg mouse lines expressing Cre-recombinase (Cre) using this regulatory region (ScxCre-L and ScxCre-H). The specificity and efficiency of Cre recombination in these Tg lines are evaluated by crossing with Rosa-CAG-LSL-tdTomato (Ai14) or ROSA26R (R26R) reporter mice. The recombination in ScxCre-H;Ai14 mice is efficiently achieved in the endogenous Scx expression domains including the branchial arches, the syndetome, and the lateral plate mesoderm. Further analysis of ScxCre-H;Ai14;ScxGFP embryos reveal that expression of the ScxGFP transgene largely overlaps with Cre activity detected by tdTomato at embryonic day 12.5 (E12.5). In ScxCre-L;R26R or ScxCre-H;R26R neonates, Cre activity is detected in tendons, ligaments, intervertebral discs, joints, and cartilage around the chondro-tendinous/ligamentous junction, the prospective enthesis. The present results suggest that ScxCre Tg lines are useful for targeting the gene specifically in the Scx-expressing domains. PMID:23349075

Sugimoto, Yuki; Takimoto, Aki; Hiraki, Yuji; Shukunami, Chisa

2013-04-01

300

Age-Dependent Penetrance of Disease in a Transgenic Mouse Model of Familial Amyotrophic Lateral Sclerosis  

Microsoft Academic Search

The mutation gly93 ? ala of Cu,Zn superoxide dismutase (SOD) is found in patients with familial amyotrophic lateral sclerosis and causes motor neuron disease when expressed in transgenic mice. The progression of clinical and pathological disease was studied in a line of mice designated G1H. Clinical disease started at 91 ± 14 days of age with fine shaking of the

Arlene Y. Chiu; Ping Zhai; Mauro C. Dal Canto; Theresa M. Peters; Young W. Kwon; Susan M. Prattis; Mark E. Gurney

1995-01-01

301

Defective axonal transport in a transgenic mouse model of amyotrophic lateral sclerosis  

Microsoft Academic Search

AMYOTROPHIC lateral sclerosis (ALS) is a degenerative disease of motor neurons, characterized by depositions of neurofilaments in the perikarya and proximal axons. The pathogenesis of ALS remains poorly understood, but two lines of evidence suggest that neurofilament accumulation may play a causal role. First, transgenic mice that overexpress neurofilament proteins show motor neuron degeneration1á€-3 and, second, variant alleles of the

Jean-François Collard; Francine Côté; Jean-Pierre Julien

1995-01-01

302

Targeted gene expression in transgenic Xenopus using the binary Gal4-UAS system  

E-print Network

Targeted gene expression in transgenic Xenopus using the binary Gal4-UAS system Katharine O phenotypes. For these reasons, we have adapted the Gal4-UAS method for targeted gene expression to Xenopus, whereas effector lines contain DNA-binding motifs for Gal4-(UAS) linked to the gene of interest. We show

Amaya, Enrique

303

Transgenic Manipulation of the Metabolism of Polyamines in Poplar Cells1  

E-print Network

, Rotorua, New Zealand (C.W.) The metabolism of polyamines (putrescine, spermidine, and spermine) has become in spermidine, and a small reduction in spermine as compared with NT cells. The conversion of labeled ornithine to a substantial reduction in putrescine and spermidine in both cell lines. The results show that: (a) Transgenic

304

Strategies to Accomplish Targeted Expression of Transgenes in Ovarian Cancer for Molecular Therapeutic Applications1  

E-print Network

Strategies to Accomplish Targeted Expression of Transgenes in Ovarian Cancer for Molecular therapy of ovarian cancer. Experimental Design: Established and primary ovarian cancer and mesothelial: Consistent activation of the MK and cox-2 promoters was noted in all of the ovarian cancer cell lines

Hemminki, Akseli

305

Passage of chronic wasting disease prion into transgenic mice expressing Rocky Mountain elk  

E-print Network

­Jakob disease in humans and scrapie in sheep. In the last few decades, CWD has spread among captive and free(s) in cervids is not known. This study describes the development of a transgenic mouse line (TgElk) homozygous on passage from cervid to mouse with both mule deer and elk CWD brain homogenates and the demonstrated

306

Production and Processing of Milk from Transgenic Goats Expressing Human Lysozyme in the Mammary Gland  

Microsoft Academic Search

The potential for applying biotechnology to benefit animal agriculture and food production has long been speculated. The addition of human milk components withintrinsicantimicrobialactivityandpositivecharge to livestock milk by genetic engineering has the poten- tial to benefit animal health, as well as food safety and production. We generated one line of transgenic goats as a model for the dairy cow designed to

E. A. Maga; C. F. Shoemaker; J. D. Rowe; R. H. BonDurant; G. B. Anderson; J. D. Murray

2006-01-01

307

Plant Physiol. (1995) 107: 125-1 30 Improved Performance of Transgenic Fructan-Accumulating  

E-print Network

under Drought Stress' Elizabeth A. H. Pilon-Smits2*, Michel J.M. Ebskamp, Matthew J. Paul, Marieke J. W for carbohydrate. Biomass production was analyzed during drought stress with the use of lines differing only- glycol-mediated drought stress than wild-type tobacco. l h e growth rate of the transgenic plants

308

Fully automatic detection of deep white matter T1 hypointense lesions in multiple sclerosis  

NASA Astrophysics Data System (ADS)

A novel method is presented for fully automatic detection of candidate white matter (WM) T1 hypointense lesions in three-dimensional high-resolution T1-weighted magnetic resonance (MR) images. By definition, T1 hypointense lesions have similar intensity as gray matter (GM) and thus appear darker than surrounding normal WM in T1-weighted images. The novel method uses a standard classification algorithm to partition T1-weighted images into GM, WM and cerebrospinal fluid (CSF). As a consequence, T1 hypointense lesions are assigned an increased GM probability by the standard classification algorithm. The GM component image of a patient is then tested voxel-by-voxel against GM component images of a normative database of healthy individuals. Clusters (?0.1 ml) of significantly increased GM density within a predefined mask of deep WM are defined as lesions. The performance of the algorithm was assessed on voxel level by a simulation study. A maximum dice similarity coefficient of 60% was found for a typical T1 lesion pattern with contrasts ranging from WM to cortical GM, indicating substantial agreement between ground truth and automatic detection. Retrospective application to 10 patients with multiple sclerosis demonstrated that 93 out of 96 T1 hypointense lesions were detected. On average 3.6 false positive T1 hypointense lesions per patient were found. The novel method is promising to support the detection of hypointense lesions in T1-weighted images which warrants further evaluation in larger patient samples.

Spies, Lothar; Tewes, Anja; Suppa, Per; Opfer, Roland; Buchert, Ralph; Winkler, Gerhard; Raji, Alaleh

2013-12-01

309

Terpenoid Metabolism in Wild-Type and Transgenic Arabidopsis PlantsW?  

PubMed Central

Volatile components, such as terpenoids, are emitted from aerial parts of plants and play a major role in the interaction between plants and their environment. Analysis of the composition and emission pattern of volatiles in the model plant Arabidopsis showed that a range of volatile components are released, primarily from flowers. Most of the volatiles detected were monoterpenes and sesquiterpenes, which in contrast to other volatiles showed a diurnal emission pattern. The active terpenoid metabolism in wild-type Arabidopsis provoked us to conduct an additional set of experiments in which transgenic Arabidopsis overexpressing two different terpene synthases were generated. Leaves of transgenic plants constitutively expressing a dual linalool/nerolidol synthase in the plastids (FaNES1) produced linalool and its glycosylated and hydroxylated derivatives. The sum of glycosylated components was in some of the transgenic lines up to 40- to 60-fold higher than the sum of the corresponding free alcohols. Surprisingly, we also detected the production and emission of nerolidol, albeit at a low level, suggesting that a small pool of its precursor farnesyl diphosphate is present in the plastids. Transgenic lines with strong transgene expression showed growth retardation, possibly as a result of the depletion of isoprenoid precursors in the plastids. In dual-choice assays with Myzus persicae, the FaNES1-expressing lines significantly repelled the aphids. Overexpression of a typical cytosolic sesquiterpene synthase resulted in the production of only trace amounts of the expected sesquiterpene, suggesting tight control of the cytosolic pool of farnesyl diphosphate, the precursor for sesquiterpenoid biosynthesis. This study further demonstrates the value of Arabidopsis for studies of the biosynthesis and ecological role of terpenoids and provides new insights into their metabolism in wild-type and transgenic plants. PMID:14630967

Aharoni, Asaph; Giri, Ashok P.; Deuerlein, Stephan; Griepink, Frans; de Kogel, Willem-Jan; Verstappen, Francel W. A.; Verhoeven, Harrie A.; Jongsma, Maarten A.; Schwab, Wilfried; Bouwmeester, Harro J.

2003-01-01

310

Production and characterization of scFvA33T1, an immunoRNase targeting colon cancer cells.  

PubMed

Within the last 10 years, the use of different RNases as therapeutic agents for various diseases has been pursued. Furthermore, the advancements of recombinant technology have allowed the assembly of proteins with different functions. In this regard, immunoribonucleases (immunoRNases) stand out as some of the most promising therapeutic candidates given their enzymatic and non-mutagenic character. Accordingly, the work reported here describes fusing RNase T1, one of the most studied members of the microbial RNase family, to the single-chain variable fragment (scFv) of a monoclonal antibody that targets the glycoprotein A33 antigen (GPA33) from human colon cancer cells. A heterologous production system, which employs the yeast Pichia pastoris, has been optimized to produce this immunoRNase (scFvA33T1) with yields of ? 5-10 mg · L(-1). The purified protein appears to be correctly folded as it retains its antigen specificity and ribonucleolytic activity. Finally, it also shows specific binding to, internalization into and toxicity against GPA33-positive cell lines compared with the control, GPA33-negative cells. Overall, it can be concluded that scFvA33T1 is a promising therapeutic fusion protein with the additional advantage that presumably it can be produced and purified in large amounts using an easily scalable yeast-based system. PMID:22748038

Tomé-Amat, Jaime; Menéndez-Méndez, Aida; García-Ortega, Lucía; Batt, Carl A; Oñaderra, Mercedes; Martínez-del-Pozo, Alvaro; Gavilanes, José G; Lacadena, Javier

2012-09-01

311

Predictors of associated autoimmune diseases (AAID) in families with type 1 diabetes (T1D). Results from the Type 1 Diabetes Genetics Consortium (T1DGC)  

PubMed Central

Background Type 1 diabetes (T1D) is a clinically heterogeneous disease. The presence of associated autoimmune diseases (AAID) may represent a distinct form of autoimmune diabetes, with involvement of specific mechanisms. The aim of this study was to find predictors of AAID in the Type 1 Diabetes Genetics Consortium (T1DGC) data set. Methods 3263 families with at least 2 siblings with T1D were included. Clinical information was obtained using questionnaires, anti-GAD and anti-IA-2 were measured and HLA-genotyping was performed. Siblings with T1D with and without AAID were compared and a multivariate regression analysis was performed to find predictors of AAID. T1D-associated HLA haplotypes were defined as the 4 most susceptible and protective, respectively. Results AAID was present in 14.4% of the T1D affected siblings. Age of diabetes onset, current age and time since diagnosis were higher, and there was a female predominance and more family history of AAID in the group with AAID, as well as more frequent anti-GAD and less frequent anti-IA2 positivity. Risk and protective HLA haplotype distributions were similar, though DRB1*0301-DQA1*0501-DQB1*0201 was more frequent in the group with AAID. In the multivariate analysis, female gender, age of onset, family history of AAID, time since diagnosis and anti-GAD positivity were significantly associated with AAID. Conclusions In patients with T1D, the presence of AAID is associated with female predominance, more frequent family history of AAID, later onset of T1D and more anti-GAD antibodies, despite longer duration of the disease. The predominance of certain HLA haplotypes suggests that specific mechanisms of disease may be involved. PMID:21744463

Wagner, Ana M; Santana, Angelo; Hernandez, Marta; Wiebe, Julia C; Novoa, Javier; Mauricio, Didac

2011-01-01

312

Expression of multiple proteins in transgenic plants  

DOEpatents

A method is disclosed for the production of multiple proteins in transgenic plants. A DNA construct for introduction into plants includes a provision to express a fusion protein of two proteins of interest joined by a linking domain including plant ubiquitin. When the fusion protein is produced in the cells of a transgenic plant transformed with the DNA construction, native enzymes present in plant cells cleave the fusion protein to release both proteins of interest into the cells of the transgenic plant. Since the proteins are produced from the same fusion protein, the initial quantities of the proteins in the cells of the plant are approximately equal.

Vierstra, Richard D. (Madison, WI); Walker, Joseph M. (Madison, WI)

2002-01-01

313

Molecular control of transgene escape from genetically modified plants  

Microsoft Academic Search

Potential risks of gene escape from transgenic crops through pollen and seed dispersal are being actively discussed and have slowed down full utilization of gene technology in crop improvement. To ban the transgene flow, barren zones and ‘terminator’ technology were developed as GMO risk management technologies in transgenic crops. Unfortunately, the technologies have not protected reliably the transgene migration to

Viktor Kuvshinov; Kimmo Koivu; Anne Kanerva; Eija Pehu

2001-01-01

314

Analysis of primitive erythroid cell proliferation and enucleation using a cyan fluorescent reporter in transgenic mice  

PubMed Central

Primitive erythropoiesis is a vital process for mammalian embryonic development. Here we report the generation and characterization of a new transgenic mouse line that expresses a histone H2B-CFP fusion protein in the nuclei of primitive erythroid cells. We demonstrate the potential of this ?-globin-histone H2B-CFP line for multicolor imaging and flow cytometry analysis. The ?-globin-H2B-CFP line was used to analyze the cell cycle distribution and proliferation of CFP-expressing primitive erythroblasts from E8.5–E13.5. We also evaluated phagocytosis of extruded CFP-positive nuclei by macrophages in fetal liver and placenta. The ?-globin-H2B-CFP transgenic mouse line adds to the available tools for studying the development of the primitive erythroid lineage. PMID:23913596

Vacaru, Andrei M.; Isern, Joan; Fraser, Stuart T.; Baron, Margaret H.

2013-01-01

315

Fast skeletal muscle-specific expression of a quail troponin I gene in transgenic mice.  

PubMed Central

We have produced seven lines of transgenic mice carrying the quail gene encoding the fast skeletal muscle-specific isoform of troponin I (TnIf). The quail DNA included the entire TnIf gene, 530 base pairs of 5'-flanking DNA, and 1.5 kilobase pairs of 3'-flanking DNA. In all seven transgenic lines, normally initiated and processed quail TnIf mRNA was expressed in skeletal muscle, where it accumulated to levels comparable to that in quail muscle. Moreover, in the three lines tested, quail TnIf mRNA levels were manyfold higher in a fast skeletal muscle (gastrocnemius) than in a slow skeletal muscle (soleus). We conclude that the cellular mechanisms directing muscle fiber type-specific TnIf gene expression are mediated by cis-regulatory elements present on the introduced quail DNA fragment and that they control TnIf expression by affecting the accumulation of TnIf mRNA. These elements have been functionally conserved since the evolutionary divergence of birds and mammals, despite the major physiological and morphological differences existing between avian (tonic) and mammalian (twitch) slow muscles. In lines of transgenic mice carrying multiple tandemly repeated copies of the transgene, an aberrant quail TnIf transcript (differing from normal TnIf mRNA upstream of exon 2) also accumulated in certain tissues, particularly lung, brain, spleen, and heart tissues. However, this aberrant transcript was not detected in a transgenic line which carries only a single copy of the quail gene. Images PMID:3244349

Hallauer, P L; Hastings, K E; Peterson, A C

1988-01-01

316

[The zig-zagging legislative policies of the European Union in relation to transgenic products].  

PubMed

The author analyses the E.U. legislative policies related to transgenic products from the 80s until nowadays, she stops in Directive 2001/18/Ce and its conversion into national law. She explains how the regulatory frame is after the recent approval of the newest rules about tracking and labelling genetically modified organisms (OMG). She also studies communitary jurisprudence about this subject according to the legislation, concretely sentence 9 September 2003 in the affair C-236/01 about commercialisation of two lines of transgenic corn. Finally she points out how legislative policies have influenced the creation and development of biotechnological enterprises. PMID:15032103

Martín Uranga, Amelia

2003-01-01

317

Combined glutathione-S-transferase M1 and T1 genetic polymorphism and tacrine hepatotoxicity  

Microsoft Academic Search

Background: Glutathione conjugation of tacrine reactive metabolites depends in part on the activity of glutathione-S -transferases (GST), of which two isozymes (GST M1 and GST T1) are polymorphically expressed.Objective and Methods: To determine whether GST M1, GST T1, and the combined GST M1 and GST T1 null genotypes predict individual susceptibility to tacrine hepatotoxicity, 141 patients with mild to moderate

Tabassome Simon; Laurent Becquemont; Murielle Mary-Krause; Isabelle de Waziers; Philippe Beaune; Christian Funck-Brentano; Patrice Jaillon

2000-01-01

318

From the Cover: Different functional roles of T1R subunits in the heteromeric taste receptors  

Microsoft Academic Search

The T1R receptors, a family of taste-specific class C G proteincoupled receptors, mediate mammalian sweet and umami tastes. The structure-function relationships of T1R receptors remain largely unknown. In this study, we demonstrate the different functional roles of T1R extracellular and transmembrane domains in ligand recognition and G protein coupling. Similar to other family C G protein-coupled receptors, the N-terminal Venus

Hong Xu; Lena Staszewski; Huixian Tang; Elliot Adler; Mark Zoller; Xiaodong Li

2004-01-01

319

Expression of a Truncated Brca1 Protein Delays Lactational Mammary Development in Transgenic Mice  

Microsoft Academic Search

To address the hypothesis that certain disease-associated mutants of the breast-ovarian cancer susceptibility gene BRCA1 have biological activity in vivo, we have expressed a truncated Brca1 protein (trBrca1) in cell-lines and in the mammary gland of transgenic mice. Immunofluorescent analysis of transfected cell-lines indicates that trBRCA1 is a stable protein and that it is localized in the cell cytoplasm. Functional

Melissa A. Brown; Hans Nicolai; Kathy Howe; Toyomasa Katagiri; El-Nasir Lalani; Kaylene J. Simpson; Nathan W. Manning; Andrew Deans; Phil Chen; Kum Kum Khanna; Mas Rina Wati; Beatrice L. Griffiths; Chun-Fang Xu; Gordon W. H. Stamp; Ellen Solomon

2002-01-01

320

Myocardial T1 Mapping with MRI: comparison of Look-Locker and MOLLI sequences  

PubMed Central

PURPOSE To evaluate the relationship between “Look-Locker” (LL) and modified Look-Locker Inversion recovery (MOLLI) approaches for T1 mapping of the myocardium. MATERIALS AND METHODS 168 myocardial T1 maps using MOLLI and 165 maps using LL were obtained in human subjects at 1.5 Tesla. The T1 values of the myocardium were calculated before and at five time points after gadolinium administration. All time and heart rate normalizations were done. The T1 values obtained were compared to determine the absolute and bias agreement. RESULTS The pre-contrast global T1 values were similar when measured by the LL and by MOLLI technique (mean 1004.9 ms +/- 120.3 vs. 1034.1 ms +/- 53.1, respectively, p = 0.26). Post-contrast myocardial T1 time from LL was significantly longer than MOLLI from 5 to 25 minutes (mean difference, LL - MOLLI was +61.8 +/- 46.4 ms, p < 0.001). No significant differences in T1 values were noted between long and short axis measurements for either MOLLI or LL. CONCLUSION Post-contrast LL and MOLLI showed very good agreement, although LL vaules are higher than MOLLI. Pre-contrast T1 values showed good agreement, however LL has greater limits of agreement. Short and long axis planes can reliably assess T1 values. PMID:21954119

Nacif, Marcelo Souto; Turkbey, Evrim B.; Gai, Neville; Nazarian, Saman; Geest, Rob J. van der; Noureldin, Radwa A; Sibley, Christopher T; Ugander, Martin; Liu, Songtao; Arai, Andrew E.; Lima, Joao A. C.; Bluemke, David A

2011-01-01

321

Proteomic analysis of known and candidate rice allergens between non-transgenic and transgenic plants.  

PubMed

Salt-soluble proteins extracted from non-transgenic and transgenic rice were evaluated for the presence of known and potential allergens by proteomic techniques. The salt-soluble proteins were extracted, separated by 1D and 2D electrophoresis, and analyzed by Western blotting. 1D immunoblot analysis with patients' sera revealed few qualitative differences between the IgE-binding proteins of the non-transgenic and transgenic rice. 1D immunoblot with antigen-specific-animal sera revealed no qualitative or quantitative differences in two known allergens, RAG2 and glyoxalase I, between non-transgenic and transgenic rice. Multiple spots containing known and novel IgE-binding proteins were detected among the salt-soluble proteins of non-transgenic rice by 2D immunoblotting. Two globulin-like proteins, a 52 kDa protein and a 63 kDa protein, were identified as novel IgE-binding proteins that are candidates for rice allergens. These globulin-like proteins were homologous to Cupin superfamily allergens. Quantitative analysis of 19, 52, and 63 kDa globulins with protein-specific-animal sera showed no significant differences in the expression of these proteins between the transgenic rice and non-transgenic rice. These results indicate that none of the known or novel endogenous IgE-binding proteins detected in this study appear to be altered by genetic modification. PMID:21300107

Satoh, Rie; Nakamura, Rika; Komatsu, Akira; Oshima, Masahiro; Teshima, Reiko

2011-04-01

322

A myelin proteolipid protein-LacZ fusion protein is developmentally regulated and targeted to the myelin membrane in transgenic mice  

PubMed Central

Transgenic mice were generated with a fusion gene carrying a portion of the murine myelin proteolipid protein (PLP) gene, including the first intron, fused to the E. coli LacZ gene. Three transgenic lines were derived and all lines expressed the transgene in central nervous system white matter as measured by a histochemical assay for the detection of beta-galactosidase activity. PLP-LacZ transgene expression was regulated in both a spatial and temporal manner, consistent with endogenous PLP expression. Moreover, the transgene was expressed specifically in oligodendrocytes from primary mixed glial cultures prepared from transgenic mouse brains and appeared to be developmentally regulated in vitro as well. Transgene expression occurred in embryos, presumably in pre- or nonmyelinating cells, rather extensively throughout the peripheral nervous system and within very discrete regions of the central nervous system. Surprisingly, beta- galactosidase activity was localized predominantly in the myelin in these transgenic animals, suggesting that the NH2-terminal 13 amino acids of PLP, which were present in the PLP-LacZ gene product, were sufficient to target the protein to the myelin membrane. Thus, the first half of the PLP gene contains sequences sufficient to direct both spatial and temporal gene regulation and to encode amino acids important in targeting the protein to the myelin membrane. PMID:8408224

1993-01-01

323

AN APPROACH TO TRANSGENIC CROP MONITORING  

EPA Science Inventory

Remote sensing by aerial or satellite images may provide a method of identifying transgenic pesticidal crop distribution in the landscape. Genetically engineered crops containing bacterial gene(s) that express an insecticidal protein from Bacillus thuringiensis (Bt) are regulated...

324

Consolidated bioprocessing of transgenic switchgrass by an engineered and evolved Clostridium thermocellum strain  

SciTech Connect

Background: Switchgrass is an abundant and dedicated bioenergy feedstock however its inherent recalcitrance is one of the economic hurdles for producing biofuels. The down-regulation of the caffeic acid O-methyl transferase (COMT) gene in the lignin pathway of switchgrass reduced lignin content and S/G ratio, and the transgenic lines showed improved fermentation yield with S. cerevisiae and C. thermocellum (ATCC 27405) in comparison to the wild-type switchgrass. Results: Here we examine the fermentation potential of the COMT transgenic switchgrass and its wild-type line, with an engineered and evolved Clostridium thermocellum (M1570) strain. The fermentation of the transgenic switchgrass had superior conversion relative to the control line with an increase of 20% and ethanol was the primary metabolite accounting for 90% of the total metabolites measured by HPLC. Conclusions: The down-regulation of the COMT gene in switchgrass reduced recalcitrance and improved microbial bioconversion yield. Moreover, these results showed ethanol as the main fermentation metabolite produced by an engineered and evolved C. thermocellum strain grown on a transgenic switchgrass.

Yee, Kelsey L [ORNL; Rodriguez Jr, Miguel [ORNL; Thompson, Olivia A [ORNL; Fu, Chunxiang [Noble Foundation; Wang, Zeng-Yu [Noble Foundation; Davison, Brian H [ORNL; Mielenz, Jonathan R [ORNL

2014-01-01

325

Production of transgenic Xenopus laevis by restriction enzyme mediated integration and nuclear transplantation.  

PubMed

Stable integration of cloned gene products into the Xenopus genome is necessary to control the time and place of expression, to express genes at later stages of embryonic development, and to define how enhancers and promoters regulate gene expression within the embryo. The protocol demonstrated here can be used to efficiently produce transgenic Xenopus laevis embryos. This transgenesis approach involves three parts: 1. Sperm nuclei are isolated from adult X. laevis testis by treatment with lysolecithin, which permeabilizes the sperm plasma membrane. 2. Egg extract is prepared by low speed centrifugation, addition of calcium to cause the extract to progress to interphase of the cell cycle, and a high-speed centrifugation to isolate interphase cytosol. 3. Nuclear transplantation: the nuclei and extract are combined with the linearized plasmid DNA to be introduced as the transgene and a small amount of restriction enzyme. During a short reaction, egg extract partially decondenses the sperm chromatin and the restriction enzyme generates chromosomal breaks that promote recombination of the transgene into the genome. The treated sperm nuclei are then transplanted into unfertilized eggs. Integration of the transgene usually occurs prior to the first embryonic cleavage such that the resulting embryos are not chimeric. These embryos can be analyzed without any need to breed to the next generation, allowing for efficient and rapid generation of transgenic embryos for analyses of promoter and gene function. Adult X. laevis resulting from this procedure also propagate the transgene through the germline and can be used to generate lines of transgenic animals for multiple purposes. PMID:20811326

Amaya, Enrique; Kroll, Kristen

2010-01-01

326

Benefits of Transgenic Plants: A Socioeconomic Perspective  

Microsoft Academic Search

\\u000a Transgenic crops have been used commercially for over ten years. So far, mostly herbicide-tolerant and insect-resistant Bt\\u000a crops have been employed. Available impact studies show that these crops are beneficial to farmers and consumers and produce\\u000a large aggregate welfare gains. Moreover, transgenic crops bring about environmental and health benefits. Bt crops in particular\\u000a are well suited also for small-scale farmers,

Matin Qaim; Arjunan Subramanian

327

Risk assessment strategies for transgenic plants  

Microsoft Academic Search

Advances in recombinant DNA technology have created advantages for the development of plants with high agro-economical values.\\u000a Since the production of transgenic plants, some issues concerning the safe use of these plants and their products have been\\u000a under debate throughout the world. In this respect, the potential risks and benefits of transgenic plants need to be evaluated\\u000a objectively. Risk assessment

Tijen Talas-O?ra?

2011-01-01

328

Comparative study of transgenic Brachypodium distachyon expressing sucrose:fructan 6-fructosyltransferases from wheat and timothy grass with different enzymatic properties.  

PubMed

Fructans can act as cryoprotectants and contribute to freezing tolerance in plant species, such as in members of the grass subfamily Pooideae that includes Triticeae species and forage grasses. To elucidate the relationship of freezing tolerance, carbohydrate composition and degree of polymerization (DP) of fructans, we generated transgenic plants in the model grass species Brachypodium distachyon that expressed cDNAs for sucrose:fructan 6-fructosyltransferases (6-SFTs) with different enzymatic properties: one cDNA encoded PpFT1 from timothy grass (Phleum pratense), an enzyme that produces high-DP levans; a second cDNA encoded wft1 from wheat (Triticum aestivum), an enzyme that produces low-DP levans. Transgenic lines expressing PpFT1 and wft1 showed retarded growth; this effect was particularly notable in the PpFT1 transgenic lines. When grown at 22 °C, both types of transgenic line showed little or no accumulation of fructans. However, after a cold treatment, wft1 transgenic plants accumulated fructans with DP = 3-40, whereas PpFT1 transgenic plants accumulated fructans with higher DPs (20 to the separation limit). The different compositions of the accumulated fructans in the two types of transgenic line were correlated with the differences in the enzymatic properties of the overexpressed 6-SFTs. Transgenic lines expressing PpFT1 accumulated greater amounts of mono- and disaccharides than wild type and wft1 expressing lines. Examination of leaf blades showed that after cold acclimation, PpFT1 overexpression increased tolerance to freezing; by contrast, the freezing tolerance of the wft1 expressing lines was the same as that of wild type plants. These results provide new insights into the relationship of the composition of water-soluble carbohydrates and the DP of fructans to freezing tolerance in plants. PMID:24385092

Tamura, Ken-Ichi; Sanada, Yasuharu; Tase, Kazuhiro; Kawakami, Akira; Yoshida, Midori; Yamada, Toshihiko

2014-04-01

329

Creation of transgenic Brassica napus L. plants expressing human alpha 2b interferon gene.  

PubMed

Spring rapeseed transgenic lines expressing human interferon alpha 2b were created by Agrobacterium-mediated transformation of aseptic plant leaf explants. The maximum antiviral activity of the leaf extracts reached 4500 IU/g fresh weight. It was determined that the antioxidant activity and the activity of an enzyme of plant antioxidant system--superoxide dismutase (SOD)--in the leaf tissues of transgenic plants increased compared to controls. There were no correlations between the interferon and antioxidant activities, as well as between SOD and interferon activities. Using the obtained transgenic rapeseed plants with high interferon and antioxidant activities as a feed additive for animals might have preventive effect on their body, increasing resistance to infections of various origins. PMID:23285745

Sakhno, L O; Kvasko, O Y; Olevinska, Z M; Spivak, M Y; Kuchuk, M V

2012-01-01

330

Degeneration of oxidative muscle fibers in HTLV-1 tax transgenic mice.  

PubMed

The HTLV-1 tax gene under control of the HTLV-1 long terminal repeat (LTR) was introduced into transgenic mice. Previously tax protein expression in the muscle and peripheral nerves of three independent mouse lines was reported. Here the localization of this transgenic protein at a cellular and subcellular level is described. Tax protein was expressed in oxidative muscle fibers that developed severe progressive atrophy. It localized to the cytoplasma where it was associated with structures resembling degenerating Z bands. This pattern of muscle fiber involvement is similar to that observed in human retroviral associated myopathy. This transgenic mouse model suggests that preferential expression of the HTLV-1 viral promoter in oxidative muscle fibers may explain the productive infection of these fibers in HTLV-1 myopathy. PMID:2688429

Nerenberg, M I; Wiley, C A

1989-12-01

331

Transgenic Expression of Human LAMA5 Suppresses Murine Lama5 mRNA and Laminin ?5 Protein Deposition  

PubMed Central

Laminin ?5 is required for kidney glomerular basement membrane (GBM) assembly, and mice with targeted deletions of the Lama5 gene fail to form glomeruli. As a tool to begin to understand factors regulating the expression of the LAMA5 gene, we generated transgenic mice carrying the human LAMA5 locus in a bacterial artificial chromosome. These mice deposited human laminin ?5 protein into basement membranes in heart, liver, spleen and kidney. Here, we characterized two lines of transgenics; Line 13 expressed ?6 times more LAMA5 than Line 25. Mice from both lines were healthy, and kidney function and morphology were normal. Examination of developing glomeruli from fetal LAMA5 transgenics showed that the human transgene was expressed at the correct stage of glomerular development, and deposited into the nascent GBM simultaneously with mouse laminin ?5. Expression of human LAMA5 did not affect the timing of the mouse laminin ?1–?5 isoform switch, or that for mouse laminin ?1–?2. Immunoelectron microscopy showed that human laminin ?5 originated in both glomerular endothelial cells and podocytes, known to be origins for mouse laminin ?5 normally. Notably, in neonatal transgenics expressing the highest levels of human LAMA5, there was a striking reduction of mouse laminin ?5 protein in kidney basement membranes compared to wildtype, and significantly lower levels of mouse Lama5 mRNA. This suggests the presence in kidney of a laminin expression monitor, which may be important for regulating the overall production of basement membrane protein. PMID:21915268

Steenhard, Brooke M.; Zelenchuk, Adrian; Stroganova, Larysa; Isom, Kathryn; St. John, Patricia L.; Andrews, Glen K.; Peterson, Kenneth R.; Abrahamson, Dale R.

2011-01-01

332

Field resistance to Fusarium oxysporum and Verticillium dahliae in transgenic cotton expressing the plant defensin NaD1  

PubMed Central

The plant defensin NaD1, from Nicotiana alata, has potent antifungal activity against a range of filamentous fungi including the two important cotton pathogens, Fusarium oxysporum f. sp. vasinfectum (Fov) and Verticillium dahliae. Transgenic cotton plants expressing NaD1 were produced and plants from three events were selected for further characterization. Homozygous plants were assessed in greenhouse bioassays for resistance to Fov. One line (D1) was selected for field trial testing over three growing seasons in soils naturally infested with Fov and over two seasons in soils naturally infested with V. dahliae. In the field trials with Fov-infested soil, line D1 had 2–3-times the survival rate, a higher tolerance to Fov (higher disease rank), and a 2–4-fold increase in lint yield compared to the non-transgenic Coker control. When transgenic line D1 was planted in V. dahliae-infested soil, plants had a higher tolerance to Verticillium wilt and up to a 2-fold increase in lint yield compared to the non-transgenic Coker control. Line D1 did not exhibit any detrimental agronomic features compared to the parent Coker control when plants were grown in non-diseased soil. This study demonstrated that the expression of NaD1 in transgenic cotton plants can provide substantial resistance to two economically important fungal pathogens. PMID:24502957

Anderson, Marilyn A.

2014-01-01

333

Integration of a c- myc Transgene Results in Disruption of the Mouse Gtf2ird1 Gene, the Homologue of the Human GTF2IRD1 Gene Hemizygously Deleted in Williams–Beuren Syndrome  

Microsoft Academic Search

Transgenic mice expressing c-myc under the control of the albumin promoter and enhancer develop liver tumors and have served as a useful model for studying the progression of hepatocarcinogenesis. The chromosomes of one line of c-myc transgenic mice carry the reciprocal translocation t(5;6)(G1;F2) adjacent to the transgene insertion site on the 5G1–ter segment translocated to chromosome 6. To characterize the

Marian E. Durkin; Catherine L. Keck-Waggoner; Nicholas C. Popescu; Snorri S. Thorgeirsson

2001-01-01

334

Expression of the oligopeptide transporter, PepT1, in larval Atlantic cod (Gadus morhua).  

PubMed

The intestinal absorption of di- and tri-peptides generally occurs via the oligopeptide transporter, PepT1. This study evaluates the expression of PepT1 in larval Atlantic cod (Gadus morhua) during the three weeks following the onset of exogenous feeding. Larval Atlantic cod were fed either wild captured zooplankton or enriched rotifers. cDNA was prepared from whole cod larvae preceding first feeding and at 1000 each Tuesday and Thursday for the following three weeks. Spatial and temporal expression patterns of PepT1 mRNA were compared between fish consuming the two prey types using in situ hybridization and quantitative real-time PCR. Results indicated that PepT1 mRNA was expressed prior to the onset of exogenous feeding. In addition, PepT1 was expressed throughout the digestive system except the esophagus and sphincter regions. Expression slightly increased following first-feeding and continued to increase throughout the study for larvae feeding on both prey types. When comparing PepT1 expression in larvae larger than 0.15-mg dry mass with expression levels in larvae prior to feeding, no differences were detected for larvae fed rotifers, but the larvae fed zooplankton had significantly greater PepT1 expression at the larger size. In addition, PepT1 expression in the zooplankton fed larvae larger than 0.15-mg dry mass had significantly greater expression than rotifer fed larvae of a similar weight. Switching prey types did not affect PepT1 expression. These results indicate that Atlantic cod PepT1 expression was slightly different relative to dietary treatment during the three weeks following first-feeding. In addition, PepT1 may play an important role in the larval nutrition since it is widely expressed in the digestive tract. PMID:18396432

Amberg, J J; Myr, C; Kamisaka, Y; Jordal, A-E O; Rust, M B; Hardy, R W; Koedijk, R; Rønnestad, I

2008-06-01

335

Durable field resistance to wheat yellow mosaic virus in transgenic wheat containing the antisense virus polymerase gene.  

PubMed

Wheat yellow mosaic virus (WYMV) has spread rapidly and causes serious yield losses in the major wheat-growing areas in China. Because it is vectored by the fungus-like organism Polymyxa graminis that survives for long periods in soil, it is difficult to eliminate by conventional crop management or fungicides. There is also only limited resistance in commercial cultivars. In this research, fourteen independent transgenic events were obtained by co-transformation with the antisense NIb8 gene (the NIb replicase of WYMV) and a selectable gene bar. Four original transgenic lines (N12, N13, N14 and N15) and an offspring line (N12-1) showed high and durable resistance to WYMV in the field. Four resistant lines were shown to have segregated and only contain NIb8 (without bar) by PCR and herbicide resistance testing in the later generations. Line N12-1 showed broad-spectrum resistance to WYMV isolates from different sites in China. After growing in the infested soil, WYMV could not be detected by tissue printing and Western blot assays of transgenic wheat. The grain yield of transgenic wheat was about 10% greater than the wild-type susceptible control. Northern blot and small RNA deep sequencing analyses showed that there was no accumulation of small interfering RNAs targeting the NIb8 gene in transgenic wheat plants, suggesting that transgene RNA silencing, a common mechanism of virus-derived disease resistance, is not involved in the process of WYMV resistance. This durable and broad-spectrum resistance to WYMV in transgenic wheat will be useful for alleviating the damage caused by WYMV. PMID:24373454

Chen, Ming; Sun, Liying; Wu, Hongya; Chen, Jiong; Ma, Youzhi; Zhang, Xiaoxiang; Du, Lipu; Cheng, Shunhe; Zhang, Boqiao; Ye, Xingguo; Pang, Junlan; Zhang, Xinmei; Li, Liancheng; Andika, Ida B; Chen, Jianping; Xu, Huijun

2014-05-01

336

Transgenic peas (Pisum sativum) expressing polygalacturonase inhibiting protein from raspberry (Rubus idaeus) and stilbene synthase from grape (Vitis vinifera).  

PubMed

The pea (Pisum sativum L.) varieties Baroness (United Kingdome) and Baccara (France) were transformed via Agrobacterium tumefaciens-mediated gene transfer with pGPTV binary vectors containing the bar gene in combination with two different antifungal genes coding for polygalacturonase-inhibiting protein (PGIP) from raspberry (Rubus idaeus L.) driven by a double 35S promoter, or the stilbene synthase (Vst1) from grape (Vitis vinifera L.) driven by its own elicitor-inducible promoter. Transgenic lines were established and transgenes combined via conventional crossing. Resveratrol, produced by Vst1 transgenic plants, was detected using HPLC and the PGIP expression was determined in functional inhibition assays against fungal polygalacturonases. Stable inheritance of the antifungal genes in the transgenic plants was demonstrated. PMID:16802117

Richter, A; Jacobsen, H-J; de Kathen, A; de Lorenzo, G; Briviba, K; Hain, R; Ramsay, G; Kiesecker, H

2006-11-01

337

Permanent neonatal diabetes in INS(C94Y) transgenic pigs.  

PubMed

Mutations in the insulin (INS) gene may cause permanent neonatal diabetes mellitus (PNDM). Ins2 mutant mouse models provided important insights into the disease mechanisms of PNDM but have limitations for translational research. To establish a large animal model of PNDM, we generated INS(C94Y) transgenic pigs. A line expressing high levels of INS(C94Y) mRNA (70-86% of wild-type INS transcripts) exhibited elevated blood glucose soon after birth but unaltered ?-cell mass at the age of 8 days. At 4.5 months, INS(C94Y) transgenic pigs exhibited 41% reduced body weight, 72% decreased ?-cell mass (-53% relative to body weight), and 60% lower fasting insulin levels compared with littermate controls. ?-cells of INS(C94Y) transgenic pigs showed a marked reduction of insulin secretory granules and severe dilation of the endoplasmic reticulum. Cataract development was already visible in 8-day-old INS(C94Y) transgenic pigs and became more severe with increasing age. Diabetes-associated pathological alterations of kidney and nervous tissue were not detected during the observation period of 1 year. The stable diabetic phenotype and its rescue by insulin treatment make the INS(C94Y) transgenic pig an attractive model for insulin supplementation and islet transplantation trials, and for studying developmental consequences of maternal diabetes mellitus. PMID:23274907

Renner, Simone; Braun-Reichhart, Christina; Blutke, Andreas; Herbach, Nadja; Emrich, Daniela; Streckel, Elisabeth; Wünsch, Annegret; Kessler, Barbara; Kurome, Mayuko; Bähr, Andrea; Klymiuk, Nikolai; Krebs, Stefan; Puk, Oliver; Nagashima, Hiroshi; Graw, Jochen; Blum, Helmut; Wanke, Ruediger; Wolf, Eckhard

2013-05-01

338

Iron Biofortification and Homeostasis in Transgenic Cassava Roots Expressing the Algal Iron Assimilatory Gene, FEA1  

PubMed Central

We have engineered the tropical root crop cassava (Manihot esculenta) to express the Chlamydomonas reinhardtii iron assimilatory gene, FEA1, in its storage roots with the objective of enhancing the root nutritional qualities. Iron levels in mature cassava storage roots were increased from 10 to 36?ppm in the highest iron accumulating transgenic lines. These iron levels are sufficient to meet the minimum daily requirement for iron in a 500?g meal. Significantly, the expression of the FEA1 gene in storage roots did not alter iron levels in leaves. Transgenic plants also had normal levels of zinc in leaves and roots consistent with the specific uptake of ferrous iron mediated by the FEA1 protein. Relative to wild-type plants, fibrous roots of FEA1 expressing plants had reduced Fe (III) chelate reductase activity consistent with the more efficient uptake of iron in the transgenic plants. We also show that multiple cassava genes involved in iron homeostasis have altered tissue-specific patterns of expression in leaves, stems, and roots of transgenic plants consistent with increased iron sink strength in transgenic roots. These results are discussed in terms of strategies for the iron biofortification of plants. PMID:22993514

Ihemere, Uzoma E.; Narayanan, Narayanan N.; Sayre, Richard T.

2012-01-01

339

Iron Biofortification and Homeostasis in Transgenic Cassava Roots Expressing the Algal Iron Assimilatory Gene, FEA1.  

PubMed

We have engineered the tropical root crop cassava (Manihot esculenta) to express the Chlamydomonas reinhardtii iron assimilatory gene, FEA1, in its storage roots with the objective of enhancing the root nutritional qualities. Iron levels in mature cassava storage roots were increased from 10 to 36?ppm in the highest iron accumulating transgenic lines. These iron levels are sufficient to meet the minimum daily requirement for iron in a 500?g meal. Significantly, the expression of the FEA1 gene in storage roots did not alter iron levels in leaves. Transgenic plants also had normal levels of zinc in leaves and roots consistent with the specific uptake of ferrous iron mediated by the FEA1 protein. Relative to wild-type plants, fibrous roots of FEA1 expressing plants had reduced Fe (III) chelate reductase activity consistent with the more efficient uptake of iron in the transgenic plants. We also show that multiple cassava genes involved in iron homeostasis have altered tissue-specific patterns of expression in leaves, stems, and roots of transgenic plants consistent with increased iron sink strength in transgenic roots. These results are discussed in terms of strategies for the iron biofortification of plants. PMID:22993514

Ihemere, Uzoma E; Narayanan, Narayanan N; Sayre, Richard T

2012-01-01

340

Transgenic mice expressing human glucocerebrosidase variants: utility for the study of Gaucher disease.  

PubMed

Gaucher disease is an autosomal recessively inherited storage disorder caused by deficiency of the lysosomal hydrolase, acid ?-glucosidase. The disease manifestations seen in Gaucher patients are highly heterogeneous as is the responsiveness to therapy. The elucidation of the precise factors responsible for this heterogeneity has been challenging as the development of clinically relevant animal models of Gaucher disease has been problematic. Although numerous murine models for Gaucher disease have been described each has limitations in their specific utility. We describe here, transgenic murine models of Gaucher disease that will be particularly useful for the study of pharmacological chaperones. We have produced stable transgenic mouse strains that individually express wild type, N370S and L444P containing human acid ?-glucosidase and show that each of these transgenic lines rescues the lethal phenotype characteristic of acid ?-glucosidase null mice. Both the N370S and L444P transgenic models show early and progressive elevations of tissue sphingolipids with L444P mice developing progressive splenic Gaucher cell infiltration. We demonstrate the potential utility of these new transgenic models for the study of Gaucher disease pathogenesis. In addition, since these mice produce only human enzyme, they are particularly relevant for the study of pharmacological chaperones that are specifically targeted to human acid ?-glucosidase and the common mutations underlying Gaucher disease. PMID:23642305

Sanders, Angela; Hemmelgarn, Harmony; Melrose, Heather L; Hein, Leanne; Fuller, Maria; Clarke, Lorne A

2013-08-01

341

Transgenic technologies to induce sterility.  

PubMed

The last few years have witnessed a considerable expansion in the number of tools available to perform molecular and genetic studies on the genome of Anopheles mosquitoes, the vectors of human malaria. As a consequence, knowledge of aspects of the biology of mosquitoes, such as immunity, reproduction and behaviour, that are relevant to their ability to transmit disease is rapidly increasing, and could be translated into concrete benefits for malaria control strategies. Amongst the most important scientific advances, the development of transgenic technologies for Anopheles mosquitoes provides a crucial opportunity to improve current vector control measures or design novel ones. In particular, the use of genetic modification of the mosquito genome could provide for a more effective deployment of the sterile insect technique (SIT) against vector populations in the field. Currently, SIT relies on the release of radiation sterilized males, which compete with wild males for mating with wild females. The induction of sterility in males through the genetic manipulation of the mosquito genome, already achieved in a number of other insect species, could eliminate the need for radiation and increase the efficiency of SIT-based strategies. This paper provides an overview of the mechanisms already in use for inducing sterility by transgenesis in Drosophila and other insects, and speculates on possible ways to apply similar approaches to Anopheles mosquitoes. PMID:19917077

Catteruccia, Flaminia; Crisanti, Andrea; Wimmer, Ernst A

2009-01-01

342

Selenoprotein-Transgenic Chlamydomonas reinhardtii  

PubMed Central

Selenium (Se) deficiency is associated with the occurrence of many diseases. However, excessive Se supplementation, especially with inorganic Se, can result in toxicity. Selenoproteins are the major forms of Se in vivo to exert its biological function. Expression of those selenoproteins, especially with the application of a newly developed system, is thus very important for studying the mechanism of Se in nutrition. The use of Chlamydomonas reinhardtii (C. reinhardtii) as a biological vector to express an heterogeneous protein is still at the initial stages of development. In order to investigate the possibility of using this system to express selenoproteins, human 15-KDa selenoprotein (Sep15), a small but widely distributed selenoprotein in mammals, was chosen for the expression platform test. Apart from the wild-type human Sep15 gene fragment, two Sep15 recombinants were constructed containing Sep15 open reading frame (ORF) and the selenocysteine insertion sequence (SECIS) element from either human Sep15 or C. reinhardtii selenoprotein W1, a highly expressed selenoprotein in this alga. Those Sep15-containing plasmids were transformed into C. reinhardtii CC-849 cells. Results showed that Sep15 fragments were successfully inserted into the nuclear genome and expressed Sep15 protein in the cells. The transgenic and wild-type algae demonstrated similar growth curves in low Se culture medium. To our knowledge, this is the first report on expressing human selenoprotein in green alga. PMID:23443677

Hou, Qintang; Qiu, Shi; Liu, Qiong; Tian, Jing; Hu, Zhangli; Ni, Jiazuan

2013-01-01

343

Cellular, Molecular and Functional Characterisation of YAC Transgenic Mouse Models of Friedreich Ataxia  

PubMed Central

Background Friedreich ataxia (FRDA) is an autosomal recessive neurodegenerative disorder, caused by a GAA repeat expansion mutation within intron 1 of the FXN gene. We have previously established and performed preliminary characterisation of several human FXN yeast artificial chromosome (YAC) transgenic FRDA mouse models containing GAA repeat expansions, Y47R (9 GAA repeats), YG8R (90 and 190 GAA repeats) and YG22R (190 GAA repeats). Methodology/Principal Findings We now report extended cellular, molecular and functional characterisation of these FXN YAC transgenic mouse models. FXN transgene copy number analysis of the FRDA mice demonstrated that the YG22R and Y47R lines each have a single copy of the FXN transgene while the YG8R line has two copies. Single integration sites of all transgenes were confirmed by fluorescence in situ hybridisation (FISH) analysis of metaphase and interphase chromosomes. We identified significant functional deficits, together with a degree of glucose intolerance and insulin hypersensitivity, in YG8R and YG22R FRDA mice compared to Y47R and wild-type control mice. We also confirmed increased somatic GAA repeat instability in the cerebellum and brain of YG22R and YG8R mice, together with significantly reduced levels of FXN mRNA and protein in the brain and liver of YG8R and YG22R compared to Y47R. Conclusions/Significance Together these studies provide a detailed characterisation of our GAA repeat expansion-based YAC transgenic FRDA mouse models that will help investigations of FRDA disease mechanisms and therapy.

Anjomani Virmouni, Sara; Sandi, Chiranjeevi; Al-Mahdawi, Sahar; Pook, Mark A.

2014-01-01

344

Strain-dependent T1 relaxation profiles in articular cartilage by MRI at microscopic resolutions.  

PubMed

To investigate the dependency of T(1) relaxation on mechanical strain in articular cartilage, quantitative magnetic resonance T(1) imaging experiments were carried out on cartilage before/after the tissue was immersed in gadolinium contrast agent and when the tissue was being compressed (up to ? 48% strains). The spatial resolution across the cartilage depth was 17.6 ?m. The T(1) profile in native tissue (without the presence of gadolinium ions) was strongly strain-dependent, which is also depth-dependent. At the modest strains (e.g., 14% strain), T(1) reduced by up to 68% in the most surface portion of the tissue. Further compression (e.g., 45% strain) reduced T(1) mostly in the middle and deep portions of the tissue. For the gadolinium-immersed tissue, both modest and heavy compressions (up to 48% strain) increased T(1) slightly but significantly, although the overall shapes of the T(1) profiles remained approximately the same regardless of the amount of strains. The complex relationships between the T(1) profiles and the mechanical strains were a direct consequence of the depth-dependent proteoglycan concentration in the tissue, which determined the tissue's mechanical properties. This finding has potential implications in the use of gadolinium contrast agent in clinical magnetic resonance imaging of cartilage (the dGEMRIC procedure), when the loading or loading history of patients is considered. PMID:21452280

Xia, Yang; Wang, Nian; Lee, Jihyun; Badar, Farid

2011-06-01

345

Petrogenesis of the Thompson Formation T1 member, Thompson Nickel Belt, Manitoba (NTS 63P12)  

Microsoft Academic Search

The Thompson Formation T1 member of the Ospwagan Group is a calcsilicate unit that has likely been derived from sedimentary rocks transitional between a 'pure' clastic system and a 'pure' carbonate system. At the Thompson mine site, it has been subjected to peak metamorphic conditions of upper amphibolite facies. There is no evidence to suggest that the T1 member has

C. G. Couëslan; Thompson Nickel Belt

346

Fast Measurement of Blood T1 in the Human Jugular Vein at 3 Tesla  

PubMed Central

Current T1 values for blood at 3T largely came from in vitro studies on animal blood or freshly drawn human blood. Measurement of blood T1 in vivo could provide more specific information, e.g. for individuals with abnormal blood composition. Here, blood T1 at 3T was measured rapidly (< 1min) in the internal jugular vein using a fast inversion-recovery technique in which multiple inversion time can be acquired rapidly due to constant refreshing of blood. Multi-shot EPI acquisition with flow compensation yielded high resolution images with minimum partial volume effect. Results showed T1 = 1852 ± 104 ms among 24 healthy adults, a value higher than for bovine blood phantoms (1584 ms at Hct of 42%). A second finding was that of a significant difference (P < 0.01) between men and women, namely T1 = 1780 ± 89 ms (n = 12) and T1 = 1924 ± 58 ms (n = 12), respectively. This difference in normal subjects is tentatively explained by the difference in Hct between genders. Interestingly, however, studies done on sickle cell anemia patients with much lower Hct (23 ± 3%, n = 10) revealed similar venous blood T1 = 1924 ± 82 ms, indicating other possible physical influences affecting blood T1. PMID:21500258

Qin, Qin; Strouse, John J.; van Zijl, Peter C.M.

2010-01-01

347

ZnT-1 extrudes zinc from mammalian cells functioning as a Zn(2+)/H(+) exchanger.  

PubMed

ZnT-1 is a Cation Diffusion Facilitator (CDF) family protein, and is present throughout the phylogenetic tree from bacteria to humans. Since its original cloning in 1995, ZnT-1 has been considered to be the major Zn(2+) extruding transporter, based on its ability to protect cells against zinc toxicity. However, experimental evidence for ZnT-1 induced Zn(2+) extrusion was not convincing. In the present study, based on the 3D crystal structure of the ZnT-1 homologue, YiiP, that predicts a homodimer that utilizes the H(+) electrochemical gradient to facilitate Zn(2+) efflux, we demonstrate ZnT-1 dependent Zn(2+) efflux from HEK 293T cells using FluoZin-3 and Fura 2 by single cell microscope based fluorescent imaging. ZnT-1 facilitates zinc efflux in a sodium-independent, pH-driven and calcium-sensitive manner. Moreover, substitution of two amino acids in the putative zinc binding domain of ZnT-1 led to nullification of Zn(2+) efflux and rendered the mutated protein incapable of protecting cells against Zn(2+) toxicity. Our results demonstrate that ZnT-1 extrudes zinc from mammalian cells by functioning as a Zn(2+)/H(+) exchanger. PMID:24951051

Shusterman, Eden; Beharier, Ofer; Shiri, Levy; Zarivach, Raz; Etzion, Yoram; Campbell, Craig R; Lee, Il-Ha; Okabayashi, Ken; Dinudom, Anuwat; Cook, David I; Katz, Amos; Moran, Arie

2014-09-01

348

Biochemical and Genetic Characterization of Propionicin T1, a New Bacteriocin from Propionibacterium thoenii  

Microsoft Academic Search

A collection of propionibacteria was screened for bacteriocin production. A new bacteriocin named propi- onicin T1 was isolated from two strains of Propionibacterium thoenii. This bacteriocin shows no sequence similarity to other bacteriocins. Propionicin T1 was active against all strains of Propionibacterium acidipropi- onici, Propionibacterium thoenii, and Propionibacterium jensenii tested and also against Lactobacillus sake NCDO 2714 but showed no

THERESE FAYE; THOR LANGSRUD; INGOLF F. NES; HELGE HOLO

2000-01-01

349

Determination of an Upper Limit for the Water Outgassing Rate of Main-belt Comet P/2012 T1 (PANSTARRS)  

NASA Astrophysics Data System (ADS)

A new Main-Belt Comet (MBC) P/2012 T1 (PANSTARRS) was discovered on 2012 October 6, approximately one month after its perihelion, by the Pan-STARRS1 survey based in Hawaii. It displayed cometary activity upon its discovery with one hypothesis being that the activity was driven by sublimation of ices; as a result, we searched for emission assumed to be driven by the sublimation of subsurface ices. Our search was of the H2O 110-101 ground state rotational line at 557 GHz from P/2012 T1 (PANSTARRS) with the Heterodyne Instrument for the Far Infrared on board the Herschel Space Observatory on 2013 January 16, when the object was at a heliocentric distance of 2.504 AU and a geocentric distance of 2.064 AU. Perihelion was in early 2012 September at a distance of 2.411 AU. While no H2O line emission was detected in our observations, we were able to derive sensitive 3? upper limits for the water production rate and column density of <7.63 × 1025 molecules s-1 and of <1.61 × 1011 cm-2, respectively. An observation taken on 2013 January 15 using the Very Large Telescope found the MBC to be active during the Herschel observation, suggesting that any ongoing sublimation due to subsurface ice was lower than our upper limit. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

O'Rourke, L.; Snodgrass, C.; de Val-Borro, M.; Biver, N.; Bockelée-Morvan, D.; Hsieh, H.; Teyssier, D.; Fernandez, Y.; Kueppers, M.; Micheli, M.; Hartogh, P.

2013-09-01

350

DETERMINATION OF AN UPPER LIMIT FOR THE WATER OUTGASSING RATE OF MAIN-BELT COMET P/2012 T1 (PANSTARRS)  

SciTech Connect

A new Main-Belt Comet (MBC) P/2012 T1 (PANSTARRS) was discovered on 2012 October 6, approximately one month after its perihelion, by the Pan-STARRS1 survey based in Hawaii. It displayed cometary activity upon its discovery with one hypothesis being that the activity was driven by sublimation of ices; as a result, we searched for emission assumed to be driven by the sublimation of subsurface ices. Our search was of the H{sub 2}O 1{sub 10}-1{sub 01} ground state rotational line at 557 GHz from P/2012 T1 (PANSTARRS) with the Heterodyne Instrument for the Far Infrared on board the Herschel Space Observatory on 2013 January 16, when the object was at a heliocentric distance of 2.504 AU and a geocentric distance of 2.064 AU. Perihelion was in early 2012 September at a distance of 2.411 AU. While no H{sub 2}O line emission was detected in our observations, we were able to derive sensitive 3{sigma} upper limits for the water production rate and column density of <7.63 Multiplication-Sign 10{sup 25} molecules s{sup -1} and of <1.61 Multiplication-Sign 10{sup 11} cm{sup -2}, respectively. An observation taken on 2013 January 15 using the Very Large Telescope found the MBC to be active during the Herschel observation, suggesting that any ongoing sublimation due to subsurface ice was lower than our upper limit.

O'Rourke, L.; Teyssier, D.; Kueppers, M. [European Space Astronomy Centre, ESAC, Villanueva de la Canada, E-28691 Madrid (Spain); Snodgrass, C.; De Val-Borro, M.; Hartogh, P. [Max Planck Institute for Solar System Research, Max-Planck-Str. 2, D-37191 Katlenburg-Lindau (Germany); Biver, N.; Bockelee-Morvan, D. [LESIA, Observatoire de Paris, CNRS, UPMC, Universite Paris-Diderot, 5 place Jules Janssen, F-92195 Meudon (France); Hsieh, H.; Micheli, M. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Fernandez, Y., E-mail: lorourke@esa.int [Department of Physics, University of Central Florida, 4000 Central Florida Blvd, Orlando, FL 32816-2385 (United States)

2013-09-01

351

High-level transgene expression in plant cells: effects of a strong scaffold attachment region from tobacco.  

PubMed Central

We have previously shown that yeast scaffold attachment regions (SARs) flanking a chimeric beta-glucuronidase (GUS) reporter gene increased per-copy expression levels by 24-fold in tobacco suspension cell lines stably transformed by microprojectile bombardment. In this study, we examined the effect of a DNA fragment originally identified in a tobacco genomic clone by its activity in an in vitro binding assay. The tobacco SAR has much greater scaffold binding affinity than does the yeast SAR, and tobacco cell lines stably transformed with constructs containing the tobacco SAR accumulated greater than fivefold more GUS enzyme activity than did lines transformed with the yeast SAR construct. Relative to the control construct, flanking the GUS gene with plant SARs increased overall expression per transgene copy by almost 140-fold. In transient expression assays, the same construct increased expression only approximately threefold relative to a control without SARs, indicating that the full SAR effect requires integration into chromosomal DNA. GUS activity in individual stable transformants was not simply proportional to transgene copy number, and the SAR effect was maximal in cell lines with fewer than approximately 10 transgene copies per tobacco genome. Lines with significantly higher copy numbers showed greatly greatly reduced expression relative to the low-copy-number lines. Our results indicate that strong SARs flanking a transgene greatly increases expression without eliminating variation between transformants. We propose that SARs dramatically reduce the severity or likelihood of homology-dependent gene silencing in cells with small numbers of transgenes but do not prevent silencing of transgenes present in many copies. PMID:8672887

Allen, G C; Hall, G; Michalowski, S; Newman, W; Spiker, S; Weissinger, A K; Thompson, W F

1996-01-01

352

High incidence of lung, bone, and lymphoid tumors in transgenic mice overexpressing mutant alleles of the p53 oncogene.  

PubMed Central

We have investigated the role of the p53 gene in oncogenesis in vivo by generating transgenic mice carrying murine p53 genomic fragments isolated from a mouse Friend erythroleukemia cell line or BALB/c mouse liver DNA. Elevated levels of p53 mRNA were detected in several tissues of two transgenic lines tested. Increased levels of p53 protein were also detected in most of the tissues analyzed by Western blotting (immunoblotting). Because both transgenes encoded p53 proteins that were antigenically distinct from wild-type p53, it was possible to demonstrate that overexpression of the p53 protein was mostly, if not entirely, due to the expression of the transgenes. Neoplasms developed in 20% of the transgenic mice, with a high incidence of lung adenocarcinomas, osteosarcomas, and lymphomas. Tissues such as ovaries that expressed the transgene at high levels were not at higher risk of malignant transformation than tissues expressing p53 protein at much lower levels. The long latent period and low penetrance suggest that overexpression of p53 alone is not sufficient to induce malignancies and that additional events are required. These observations provide direct evidence that mutant alleles of the p53 oncogene have oncogenic potential in vivo and that different cell types show intrinsic differences in susceptibility to malignant transformation by p53. Since recent data suggest that p53 may be a recessive oncogene, it is possible that the elevated tumor incidence results from functional inactivation of endogenous p53 by overexpression of the mutant transgene. The high incidence of lung and bone tumors suggests that p53 transgenic mice may provide a useful model to investigate the molecular events that underlie these malignancies in humans. Images PMID:2476668

Lavigueur, A; Maltby, V; Mock, D; Rossant, J; Pawson, T; Bernstein, A

1989-01-01

353

Loss of PiT-1 results in abnormal endocytosis in the yolk sac visceral endoderm.  

PubMed

PiT-1 protein is a transmembrane sodium-dependent phosphate (Pi) transporter. PiT-1 knock out (KO) embryos die from largely unknown causes by embryonic day (E) 12.5. We tested the hypothesis that PiT-1 is required for endocytosis in the embryonic yolk sac (YS) visceral endoderm (VE). Here we present data supporting that PiT-1 KO results in a YS remodeling defect and decreased endocytosis in the YS VE. The remodeling defect is not due to an upstream cardiomyocyte requirement for PiT-1, as SM22?Cre-specific KO of PiT-1 in the developing heart and the YS mesodermal layer (ME) does not recapitulate the PiT-1 global KO phenotype. Furthermore, we find that high levels of PiT-1 protein localize to the YS VE apical membrane. Together these data support that PiT-1 is likely required in YS VE. During normal development maternal immunoglobulin (IgG) is endocytosed into YS VE and accumulates in the apical side of the VE in a specialized lysosome termed the apical vacuole (AV). We have identified a reduction in PiT-1 KO VE cell height and a striking loss of IgG accumulation in the PiT-1 KO VE. The endocytosis genes Tfeb, Lamtor2 and Snx2 are increased at the RNA level. Lysotracker Red staining reveals a loss of distinct AVs, and yolk sacs incubated ex vivo with phRODO Green Dextran for Endocytosis demonstrate a functional loss of endocytosis. As yolk sac endocytosis is controlled in part by microautophagy, but expression of LC3 had not been examined, we investigated LC3 expression during yolk sac development and found stage-specific LC3 RNA expression that is predominantly from the YS VE layer at E9.5. Normalized LC3-II protein levels are decreased in the PiT-1 KO YS, supporting a requirement for PiT-1 in autophagy in the YS. Therefore, we propose the novel idea that PiT-1 is central to the regulation of endocytosis and autophagy in the YS VE. PMID:25138534

Wallingford, Mary C; Giachelli, Cecilia M

2014-08-01

354

3-Iodothyronamine (T1AM): A New Player on the Thyroid Endocrine Team?  

PubMed Central

3-Iodothyronamine (T1AM) is an endogenous compound with chemical features that are similar to thyroid hormone. T1AM has a carbon skeleton identical to that of T4 and contains a single carbon-iodine bond. Theoretically, T1AM could be produced from T4 by enzymatic decarboxylation and deiodination. Recent studies show that T1AM and higher iodinated thyronamines are subject to similar metabolic processing as iodothyronines such as T4, suggesting a biological linkage between iodothyronines and iodothyronamines. In addition, single doses of T1AM administered to rodents induce a hypometabolic state that in certain ways resembles hibernation and is opposite to the effects of excess T4. This review will discuss the latest developments on this recently discovered thyroid hormone derivative. PMID:19116337

Scanlan, Thomas S.

2009-01-01

355

A primer for using transgenic insecticidal cotton in developing countries.  

PubMed

Many developing countries face the decision of whether to approve the testing and commercial use of insecticidal transgenic cotton and the task of developing adequate regulations for its use. In this review, we outline concepts and provide information to assist farmers, regulators and scientists in making decisions concerning this technology. We address seven critical topics: 1) molecular and breeding techniques used for the development of transgenic cotton cultivars, 2) properties of transgenic cotton cultivars and their efficacy against major insect pests, 3) agronomic performance of transgenic cotton in developing countries, 4) factors affecting transgene expression, 5) impact of gene flow between transgenic and non-transgenic cotton, 6) non-target effects of transgenic cotton, and 7) management of pest resistance to transgenic cotton. PMID:19613464

Showalter, Ann M; Heuberger, Shannon; Tabashnik, Bruce E; Carrière, Yves; Coates, Brad

2009-01-01

356

T1? MRI in Alzheimer’s Disease: Detection of Pathological Changes in Medial Temporal Lobe  

PubMed Central

BACKGROUND The need of an early and noninvasive diagnosis of AD requires the development of imaging-based techniques. As an alternative, the magnetic resonance image (MRI) relaxation time constant (T1? ) was measured in brains of Alzheimer’s disease (AD), mild-cognitive impairment (MCI), and age-matched controls in order to determine whether T1? values correlated with the neurological diagnosis. METHODS MRI was performed on AD (n = 48), MCI (n = 45), and age-matched control (n = 41), on a 1.5 Tesla Siemens clinical MRI scanner. T1? maps were generated by fitting each pixel’s intensity as a function of the duration of the spin-lock pulse. T1? values were calculated from the gray matter (GM) and white matter (WM) of medial temporal lobe (MTL). RESULTS GM and WM T1? values were 87.5 ± 1.2 ms and 80.5 ± 1.4 ms, respectively, in controls, 90.9 ± 1.3 ms and 84.1 ± 1.7 ms in MCI, and 91.9 ±.8 ms and 88.3 ± 1.3 ms in AD cohorts. Compared to control, AD patients showed 9% increased WM T1? and 5% increased GM T1?. Compared to control, MCI individuals showed 4% increased T1? both in WM and GM. A 5% increased T1? was found in WM of AD over MCI. CONCLUSION The increased T1? in WM and GM of MTL in AD may be associated with the pathological changes that are not evident on conventional MRI. PMID:20331502

Haris, Mohammad; Singh, Anup; Cai, Kejia; McArdle, Erin; Fenty, Matthew; Davatzikos, Christos; Trojanowski, John Q.; Melhem, Elias R.; Clark, Christopher M.; Borthakur, Arijitt

2010-01-01

357

Virus-induced gene silencing in transgenic plants: transgene silencing and reactivation associate with two patterns of transgene body methylation.  

PubMed

We used bisulfite sequencing to study the methylation of a viral transgene whose expression was silenced upon plum pox virus infection of the transgenic plant and its subsequent recovery as a consequence of so-called virus-induced gene silencing (VIGS). VIGS was associated with a general increase in the accumulation of small RNAs corresponding to the coding region of the viral transgene. After VIGS, the transgene promoter was not methylated and the coding region showed uneven methylation, with the 5' end being mostly unmethylated in the recovered tissue or mainly methylated at CG sites in regenerated silenced plants. The methylation increased towards the 3' end, which showed dense methylation in all three contexts (CG, CHG and CHH). This methylation pattern and the corresponding silenced status were maintained after plant regeneration from recovered silenced tissue and did not spread into the promoter region, but were not inherited in the sexual offspring. Instead, a new pattern of methylation was observed in the progeny plants consisting of disappearance of the CHH methylation, similar CHG methylation at the 3' end, and an overall increase in CG methylation in the 5' end. The latter epigenetic state was inherited over several generations and did not correlate with transgene silencing and hence virus resistance. These results suggest that the widespread CG methylation pattern found in body gene bodies located in euchromatic regions of plant genomes may reflect an older silencing event, and most likely these genes are no longer silenced. PMID:24916614

Zhao, Mingmin; San León, David; Delgadillo, Ma Otilia; García, Juan Antonio; Simón-Mateo, Carmen

2014-08-01

358

Transgenic tobacco expressing Zephyranthes grandiflora agglutinin confers enhanced resistance to aphids.  

PubMed

Plant lectins have been reported as transgenic resistance factors against a variety of insect pests. Herein, homologous analysis demonstrated that Zephyranthes grandiflora agglutinin (ZGA) exhibited high similarity with other monocot mannose-binding lectins (MBLs). Phylogenetic analysis revealed that it had taxonomical relationships with insecticidal MBLs. Subsequently, a plasmid expression vector pBI121 containing zga gene (pBIZGA) was constructed using the zga sequence, under the control of CaMV35S promoter and nos terminator. pBIZGA was then integrated into the genome of Nicotiana tabacum L. Polymerase chain reaction and Southern blot analysis demonstrated that this zga gene was integrated into the plant genome. Western blotting and agglutinating activity analysis also showed that transgenic tobacco plants expressed different levels of ZGA. Carbohydrate inhibition analysis indicated that recombinant ZGA and the native shared the same carbohydrate-binding specificity. Moreover, genetic analysis confirmed Mendelian segregation (3:1) of the transgenic in T1 progenies. In planta bioassays on T0 plants and their progenies indicated that expressed ZGA had an effect on reducing the survivability and fecundity of tobacco aphids (Myzus nicotianae). These findings demonstrate that the novel zga gene of ZGA can be expressed in crop plants susceptible to various sap-sucking insects. PMID:19067248

Ye, Song-hua; Chen, Sheng; Zhang, Fan; Wang, Wei; Tian, Qin; Liu, Jin-zhi; Chen, Fang; Bao, Jin-ku

2009-09-01

359

Generation of Cre Transgenic Mice with Postnatal RPE-Specific Ocular Expression  

PubMed Central

Purpose. To generate and characterize a constitutively active, RPE-specific, cre-expressing transgenic mouse line. This line can be used to create RPE-specific knockouts by crossing with mice harboring loxP-flanked (floxed) genes. Methods. A transgene construct was assembled with the BEST1 promoter driving cre expression. Transgenic mice were generated on a C57BL/6 background. Cre expression was assessed by immunofluorescence and Western blot analysis. Cre enzymatic activity was tested by crossing to three lines with floxed DNA regions and detecting deletion of the intervening sequences or through histochemical detection of lacZ activity. Potential cre-mediated toxicity was assessed by retinal histology up to 24 months of age and by electroretinography. Results. The BEST1-cre line with expression in the highest percentage of RPE cells displayed a patchy mosaic expression pattern, with 50% to 90% of RPE cells expressing cre. In mice outcrossed to a mixed B6/129 background, expression was consistently found in 90% of RPE cells. Within the eye, only the RPE cells were immunoreactive with an anti-cre antibody. Maximum cre expression quantified by Western blot analysis occurred at P28. Crosses with three lines containing floxed sequences revealed RPE-specific cre activity in the eye and extraocular expression limited to the testes. Histology and electroretinography showed no cre-mediated RPE toxicity. Conclusions. This BEST1-cre transgenic line enables generation of RPE-specific knockout mice. The mosaic expression pattern provides an internal control; the non–cre-expressing RPE cells continue to express the floxed genes. These mice should facilitate study of the multifunctional RPE and the generation of mouse models of human retinal disease. PMID:21212186

Iacovelli, Jared; Zhao, Chen; Wolkow, Natalie; Veldman, Peter; Gollomp, Kandace; Ojha, Pallavi; Lukinova, Nina; King, Ayala; Feiner, Leonard; Esumi, Noriko; Zack, Donald J.; Pierce, Eric A.; Vollrath, Douglas

2011-01-01

360

Origin and Spread of Bos taurus: New Clues from Mitochondrial Genomes Belonging to Haplogroup T1  

PubMed Central

Background Most genetic studies on modern cattle have established a common origin for all taurine breeds in the Near East, during the Neolithic transition about 10 thousand years (ka) ago. Yet, the possibility of independent and/or secondary domestication events is still debated and is fostered by the finding of rare mitochondrial DNA (mtDNA) haplogroups like P, Q and R. Haplogroup T1, because of its geographic distribution, has been the subject of several investigations pointing to a possible independent domestication event in Africa and suggesting a genetic contribution of African cattle to the formation of Iberian and Creole cattle. Whole mitochondrial genome sequence analysis, with its proven effectiveness in improving the resolution of phylogeographic studies, is the most appropriate tool to investigate the origin and structure of haplogroup T1. Methodology A survey of >2200 bovine mtDNA control regions representing 28 breeds (15 European, 10 African, 3 American) identified 281 subjects belonging to haplogroup T1. Fifty-four were selected for whole mtDNA genome sequencing, and combined with ten T1 complete sequences from previous studies into the most detailed T1 phylogenetic tree available to date. Conclusions Phylogenetic analysis of the 64 T1 mitochondrial complete genomes revealed six distinct sub-haplogroups (T1T1f). Our data support the overall scenario of a Near Eastern origin of the T1 sub-haplogroups from as much as eight founding T1 haplotypes. However, the possibility that one sub-haplogroup (T1d) arose in North Africa, in domesticated stocks, shortly after their arrival from the Near East, can not be ruled out. Finally, the previously identified “African-derived American" (AA) haplotype turned out to be a sub-clade of T1c (T1c1a1). This haplotype was found here for the first time in Africa (Egypt), indicating that it probably originated in North Africa, reached the Iberian Peninsula and sailed to America, with the first European settlers. PMID:22685589

Bonfiglio, Silvia; Ginja, Catarina; De Gaetano, Anna; Achilli, Alessandro; Olivieri, Anna; Colli, Licia; Tesfaye, Kassahun; Agha, Saif Hassan; Gama, Luis T.; Cattonaro, Federica; Penedo, M. Cecilia T; Ajmone-Marsan, Paolo; Torroni, Antonio; Ferretti, Luca

2012-01-01

361

Relationship between expression levels and atherogenesis in scavenger receptor Class B, Type I Transgenics  

SciTech Connect

Both in vitro and in vivo studies of SR-BI have implicated it as a likely participant in the metabolism of HDL cholesterol. To investigate SR-BI's effect on atherogenesis we examined two lines of SR-BI transgenic mice with high (10-fold increases) and low (2-fold increases) in SR-BI expression in an inbred mouse background hemizygous for a human apo B transgene. Unlike non-HDL cholesterol levels which minimally differed in the various groups of animals, HDL cholesterol levels were inversely related to SR-BI expression. Mice with the low expression SR-BI transgene had a 50% reduction in HDL cholesterol while the high expression SR-BI transgene was associated with two-fold decreases in HDL as well as dramatic alterations in HDL composition and size including the near absence of a-migrating particles as determined by 2-dimensional electrophoresis. The low expression SR-BI/apo B transgenics had more than a two-fold decrease in the development of diet induced fatty streak lesions compared t o the apo B transgenics (4448{+-}1908 {mu}m2/aorta to 10133 {+-} 4035 {mu}m2/aorta; p<0.001), while the high expression SR-BI/apo B transgenics had an atherogenic response similar to that of the apo B transgenics (14692{+-}7238 {mu}m2/aorta) but three-fold greater than the low SR-BI/apo B mice (p<0.001). The prominent anti-atherogenic effect of moderate SR-BI expression provides in vivo support for the hypothesis that HDL functions to inhibit atherogenesis through its interactions with SR-BI in facilitating reverse cholesterol transport. The failure of the high SR-BI/apo B transgenics to have similar or even greater reductions in atherogenesis suggests that the changes resulting from extremely high SR-BI expression including dramatic changes in lipoproteins may have both pro- and anti-atherogenic consequences illustrating the complexity of the relationship between SR-BI and atherogenesis.

Ueda, Yukihiko; Gong, Elaine; Royer, Lori; Cooper, Philip N.; Francone, Omar L; Rubin, Edward M.

2000-03-15

362

Technical advance: stringent control of transgene expression in Arabidopsis thaliana using the Top10 promoter system  

NASA Technical Reports Server (NTRS)

We show that the tightly regulated tetracycline-sensitive Top10 promoter system (Weinmann et al. Plant J. 1994, 5, 559-569) is functional in Arabidopsis thaliana. A pure breeding A. thaliana line (JL-tTA/8) was generated which expressed a chimeric fusion of the tetracycline repressor and the activation domain of Herpes simplex virus (tTA), from a single transgenic locus. Plants from this line were crossed with transgenics carrying the ER-targeted green fluorescent protein coding sequence (mGFP5) under control of the Top10 promoter sequence. Progeny from this cross displayed ER-targeted GFP fluorescence throughout the plant, indicating that the tTA-Top10 promoter interaction was functional in A. thaliana. GFP expression was repressed by 100 ng ml-1 tetracycline, an order of magnitude lower than the concentration used previously to repress expression in Nicotiana tabacum. Moreover, the level of GFP expression was controlled by varying the concentration of tetracycline in the medium, allowing a titred regulation of transgenic activity that was previously unavailable in A. thaliana. The kinetics of GFP activity were determined following de-repression of the Top10:mGFP5 transgene, with a visible ER-targeted GFP signal appearing from 24 to 48 h after de-repression.

Love, J.; Scott, A. C.; Thompson, W. F.; Brown, C. S. (Principal Investigator)

2000-01-01

363

Generation and characterization of gsu?:EGFP transgenic zebrafish for evaluating endocrine-disrupting effects.  

PubMed

The glycoprotein subunit ? (gsu?) gene encodes the shared ? subunit of the three pituitary heterodimeric glycoprotein hormones: follicle-stimulating hormone ? (Fsh?), luteinizing hormone ? (Lh?) and thyroid stimulating hormone ? (Tsh?). In our current study, we identified and characterized the promoter region of zebrafish gsu? and generated a stable gsu?:EGFP transgenic line, which recapitulated the endogenous gsu? expression in the early developing pituitary gland. A relatively conserved regulatory element set is presented in the promoter regions of zebrafish and three other known mammalian gsu? promoters. Our results also demonstrated that the expression patterns of the gsu?:EGFP transgene were all identical to those expression patterns of the endogenous gsu? expression in the pituitary tissue when our transgenic fish were treated with various endocrine chemicals, including forskolin (FSK), SP600125, trichostatin A (TSA), KClO4, dexamethasone (Dex), ?-estradiol and progesterone. Thus, this gsu?:EGFP transgenic fish reporter line provides another valuable tool for investigating the lineage development of gsu?-expressing gonadotrophins and the coordinated regulation of various glycoprotein hormone subunit genes. These reporter fish can serve as a novel platform to perform screenings of endocrine-disrupting chemicals (EDCs) in vivo as well. PMID:24747804

Cheng, Xiaoxia; Chen, Xiaowen; Jin, Xia; He, Jiangyan; Yin, Zhan

2014-07-01

364

Tetracycline-inducible system for regulation of skeletal muscle-specific gene expression in transgenic mice  

NASA Technical Reports Server (NTRS)

Tightly regulated control of over-expression is often necessary to study one aspect or time point of gene function and, in transgenesis, may help to avoid lethal effects and complications caused by ubiquitous over-expression. We have utilized the benefits of an optimized tet-on system and a modified muscle creatine kinase (MCK) promoter to generate a skeletal muscle-specific, doxycycline (Dox) controlled over-expression system in transgenic mice. A DNA construct was generated in which the codon optimized reverse tetracycline transactivator (rtTA) was placed under control of a skeletal muscle-specific version of the mouse MCK promoter. Transgenic mice containing this construct expressed rtTA almost exclusively in skeletal muscles. These mice were crossed to a second transgenic line containing a bi-directional promoter centered on a tet responder element driving both a luciferase reporter gene and a tagged gene of interest; in this case the calpain inhibitor calpastatin. Compound hemizygous mice showed high level, Dox dependent muscle-specific luciferase activity often exceeding 10,000-fold over non-muscle tissues of the same mouse. Western and immunocytochemical analysis demonstrated similar Dox dependent muscle-specific induction of the tagged calpastatin protein. These findings demonstrate the effectiveness and flexibility of the tet-on system to provide a tightly regulated over-expression system in adult skeletal muscle. The MCKrtTA transgenic lines can be combined with other transgenic responder lines for skeletal muscle-specific over-expression of any target gene of interest.

Grill, Mischala A.; Bales, Mark A.; Fought, Amber N.; Rosburg, Kristopher C.; Munger, Stephanie J.; Antin, Parker B.

2003-01-01

365

Disappearing "T1 black holes" in an animal model of multiple sclerosis.  

PubMed

Brain MRI in multiple sclerosis (MS) frequently shows areas of hypointensity in the white matter on T1 weighted sequences ("T1 black holes"). These areas are thought to be consistent with irreversible axonal loss. In this study T1 black holes were characterized in Theiler's Murine Encephalitis Virus infection, an established model of demyelinating diseases in mice. The spectrum of TMEV is broad in different strains. C57BL/6J mice develop a self-limited brain disease, which resolves within 4-6 weeks. We followed six mice with serial MRI and MRS on days 0, 3,7,21 and 45. The studies were performed in a 7 Tesla magnet. Periventricular and parahippocampal T1 black holes seen as early as 3 days, with decreasing NAA/Cre ratio on MRS. The extent of pathology was most severe on days 3 and 7. T1 black holes are thought to be consistent with areas of irreversible axonal loss. This is challenged by our observations of resolution of T1 black holes by day 45. This was concomitant with the normalization of MRS findings in the areas of interest. We conclude that T1 black holes may represent a transient phenomenon in this model of MS. The recovery of these areas studied suggests an active repair mechanism. PMID:14977539

Pirko, Istvan; Johnson, Aaron; Gamez, Jeff; Macura, Slobodan I; Rodriguez, Moses

2004-05-01

366

Compartmental study of T(1) and T(2) in rat brain and trigeminal nerve in vivo.  

PubMed

The integrated T(1)-T(2) characteristics of rat brain and trigeminal nerve water were studied in vivo using a rapid method for acquiring a series of images that depend on T(1) and T(2) relaxation times. Gray matter regions showed only one signal component in both the T(1) and T(2) domains. Trigeminal nerve, however, which has been shown previously to exhibit three T(2) components, was found to also exhibit three T(1) components. The correlations between these T(1) and T(2) components were demonstrated by uniquely filtering out each of the three T(2) components using an inversion-recovery preparation, as determined by the component T(1) values. Based on previous works, it is postulated that each of these three signal components is derived from a unique microanatomical region of the nerve. Knowledge of these T(1) components may thus prove valuable in devising novel methods of identifying the presence and quantifying the volume of tissue subtypes such as myelin. PMID:11810670

Does, Mark D; Gore, John C

2002-02-01

367

Designing and implementing sample and data collection for an international genetics study: the Type 1 Diabetes Genetics Consortium (T1DGC)  

PubMed Central

Background and Purpose?The Type 1 Diabetes Genetics Consortium (T1DGC) is an international project whose primary aims are to: (a) discover genes that modify type 1 diabetes risk; and (b) expand upon the existing genetic resources for type 1 diabetes research. The initial goal was to collect 2500 affected sibling pair (ASP) families worldwide. Methods?T1DGC was organized into four regional networks (Asia-Pacific, Europe, North America, and the United Kingdom) and a Coordinating Center. A Steering Committee, with representatives from each network, the Coordinating Center, and the funding organizations, was responsible for T1DGC operations. The Coordinating Center, with regional network representatives, developed study documents and data systems. Each network established laboratories for: DNA extraction and cell line production; human leukocyte antigen genotyping; and autoantibody measurement. Samples were tracked from the point of collection, processed at network laboratories and stored for deposit at National Institute for Diabetes and Digestive and Kidney Diseases (NIDDK) Central Repositories. Phenotypic data were collected and entered into the study database maintained by the Coordinating Center. Results?T1DGC achieved its original ASP recruitment goal. In response to research design changes, the T1DGC infrastructure also recruited trios, cases, and controls. Results of genetic analyses have identified many novel regions that affect susceptibility to type 1 diabetes. T1DGC created a resource of data and samples that is accessible to the research community. Limitations?Participation in T1DGC was declined by some countries due to study requirements for the processing of samples at network laboratories and/or final deposition of samples in NIDDK Central Repositories. Re-contact of participants was not included in informed consent templates, preventing collection of additional samples for functional studies. Conclusions?T1DGC implemented a distributed, regional network structure to reach ASP recruitment targets. The infrastructure proved robust and flexible enough to accommodate additional recruitment. T1DGC has established significant resources that provide a basis for future discovery in the study of type 1 diabetes genetics. PMID:20603248

Hilner, Joan E; Perdue, Letitia H; Sides, Elizabeth G; Pierce, June J; Wagner, Ana M; Aldrich, Alan; Loth, Amanda; Albret, Lotte; Wagenknecht, Lynne E; Nierras, Concepcion; Akolkar, Beena

2010-01-01

368

Simultaneous T1 measurements and proton resonance frequency shift based thermometry using variable flip angles.  

PubMed

A method is presented which allows precise temperature and longitudinal (T(1)) relaxation time measurements with high spatial and temporal resolution. This is achieved by combining dynamic variable flip angle based T(1) relaxation mapping with proton resonance frequency shift based thermometry. Herein, dynamic T(1) mapping is either used as a complementary measure of temperature or for the detection of T(1) contrast agent release. For the first application, the temperature evolution during a high-intensity focused ultrasound tissue ablation experiment was measured in both, porcine fat and muscle, simultaneously. In this application, temperature accuracies of 2.5 K for T(1)-based thermometry in fat and 1.2 K for proton resonance frequency shift-based thermometry in muscle were observed. The second application relates to MR-guidance of high-intensity focused ultrasound-induced local drug delivery by means of thermo-sensitive liposomes labeled with a T(1) contrast agent (Gd-HPDO3A). When the measured temperature exceeded the phase transition temperature of the liposomes, T(1) was observed to decrease with a good temporal and spatial correlation due to the release of Gd-HPDO3A. The presented results demonstrate the feasibility of the proposed method for two important applications in MR-guided noninvasive therapy. It offers a high temporal resolution when compared with interleaved Look-Locker based T(1) mapping techniques and thus represents an interesting candidate for simultaneous real-time monitoring of T(1) and temperature changes. PMID:22052363

Hey, S; de Smet, M; Stehning, C; Grüll, H; Keupp, J; Moonen, C T W; Ries, M

2012-02-01

369

Optimization of Iron Oxide Nanoparticle Detection Using Ultrashort TE Pulse Sequences: Comparison of T1, T2* and Synergistic T1-T2* Contrast Mechanisms  

PubMed Central

Iron oxide nanoparticles (IONPs) are used in various MRI applications as negative contrast agents. A major challenge is to distinguish regions of signal void due to IONPs from those due to low signal tissues or susceptibility artifacts. To overcome this limitation, several positive contrast strategies have been proposed. Relying on IONP T1 shortening effects to generate positive contrast is a particularly appealing strategy since it should provide additional specificity when associated with the usual negative contrast from T2* effects. In this paper, Ultrashort TE (UTE) imaging is shown to be a powerful technique which can take full advantage of both contrast mechanisms. Methods of comparing T1 and T2* contrast efficiency are described and general rules that allow optimizing IONP detection sensitivity are derived. Contrary to conventional wisdom, optimizing T1 contrast is often a good strategy for imaging IONPs. Under certain conditions, subtraction of a later echo signal from the UTE signal not only improves IONP specificity by providing long T2* background suppression, but also increases detection sensitivity, as it enables a synergistic combination of usually antagonist T1 and T2* contrasts. In vitro experiments support our theory and a molecular imaging application is demonstrated using tumor-targeted IONPs in vivo. PMID:21305596

Girard, O. M.; Du, J.; Agemy, L.; Sugahara, K. N.; Kotamraju, V. R.; Ruoslahti, E.; Bydder, G. M.; Mattrey, R. F.

2010-01-01

370

Chimeric elk/mouse prion proteins in transgenic mice  

PubMed Central

Chronic wasting disease (CWD) of deer and elk is a highly communicable neurodegenerative disorder caused by prions. Investigations of CWD are hampered by slow bioassays in transgenic (Tg) mice. Towards the development of Tg mice that will be more susceptible to CWD prions, we created a series of chimeric elk/mouse transgenes that encode the N terminus of elk PrP (ElkPrP) up to residue Y168 and the C terminus of mouse PrP (MoPrP) beyond residue 169 (mouse numbering), designated Elk3M(SNIVVK). Between codons 169 and 219, six residues distinguish ElkPrP from MoPrP: N169S, T173N, V183I, I202V, I214V and R219K. Using chimeric elk/mouse PrP constructs, we generated 12 Tg mouse lines and determined incubation times after intracerebral inoculation with the mouse-passaged RML scrapie or Elk1P CWD prions. Unexpectedly, one Tg mouse line expressing Elk3M(SNIVVK) exhibited incubation times of <70 days when inoculated with RML prions; a second line had incubation times of <90 days. In contrast, mice expressing full-length ElkPrP had incubation periods of >250 days for RML prions. Tg(Elk3M,SNIVVK) mice were less susceptible to CWD prions than Tg(ElkPrP) mice. Changing three C-terminal mouse residues (202, 214 and 219) to those of elk doubled the incubation time for mouse RML prions and rendered the mice resistant to Elk1P CWD prions. Mutating an additional two residues from mouse to elk at codons 169 and 173 increased the incubation times for mouse prions to >300 days, but made the mice susceptible to CWD prions. Our findings highlight the role of C-terminal residues in PrP that control the susceptibility and replication of prions. PMID:23100369

Tamguney, Gultekin; Giles, Kurt; Oehler, Abby; Johnson, Natrina L.; DeArmond, Stephen J.

2013-01-01

371

Overexpression of TaLEA Gene from Tamarix androssowii Improves Salt and Drought Tolerance in Transgenic Poplar (Populus simonii × P. nigra)  

PubMed Central

Late embryogenesis abundant (LEA) genes were confirmed to confer resistance to drought and water deficiency. An LEA gene from Tamarixandrossowii (named TaLEA) was transformed into Xiaohei poplar (Populussimonii × P. nigra) via Agrobacterium. Twenty-five independent transgenic lines were obtained that were resistant to kanamycin, and 11 transgenic lines were randomly selected for further analysis. The polymerase chain reaction (PCR) and ribonucleic acid (RNA) gel blot indicated that the TaLEA gene had been integrated into the poplar genome. The height growth rate, malondialdehyde (MDA) content, relative electrolyte leakage and damages due to salt or drought to transgenic and non-transgenic plants were compared under salt and drought stress conditions. The results showed that the constitutive expression of the TaLEA gene in transgenic poplars could induce an increase in height growth rate and a decrease in number and severity of wilted leaves under the salt and drought stresses. The MDA content and relative electrolyte leakage in transgenic lines under salt and drought stresses were significantly lower compared to those in non-transgenic plants, indicating that the TaLEA gene may enhance salt and drought tolerance by protecting cell membranes from damage. Moreover, amongst the lines analyzed for stress tolerance, the transgenic line 11 (T11) showed the highest tolerance levels under both salinity and drought stress conditions. These results indicated that the TaLEA gene could be a salt and drought tolerance candidate gene and could confer a broad spectrum of tolerance under abiotic stresses in poplars. PMID:23840708

Gao, Weidong; Bai, Shuang; Li, Qingmei; Gao, Caiqiu; Liu, Guifeng; Li, Guangde; Tan, Feili

2013-01-01

372

Production of transgenic goats expressing human coagulation factor IX in the mammary glands after nuclear transfer using transfected fetal fibroblast cells.  

PubMed

There are growing numbers of recombinant proteins that have been expressed in milk. Thus one can consider the placement of any gene of interest under the control of the regulatory elements of a milk protein gene in a dairy farm animal. Among the transgene introducing techniques, only nuclear transfer (NT) allows 100 % efficiency and bypasses the mosaicism associated with counterpart techniques. In this study, in an attempt to produce a transgenic goat carrying the human coagulation factor IX (hFIX) transgene, goat fetal fibroblasts were electroporated with a linearized marker-free construct in which the transgene was juxtaposed to ?-casein promoter designed to secret the recombinant protein in goat milk. Two different lines of transfected cells were used as donors for NT to enucleated oocytes. Two transgenic goats were liveborn. DNA sequencing of the corresponding transgene locus confirmed authenticity of the cloning procedure and the complementary experiments on the whey demonstrated expression of human factor IX in the milk of transgenic goats. In conclusion, our study has provided the groundwork for a prosperous and promising approach for large-scale production and therapeutic application of hFIX expressed in transgenic goats. PMID:22869287

Amiri Yekta, Amir; Dalman, Azam; Eftekhari-Yazdi, Poopak; Sanati, Mohammad Hossein; Shahverdi, Abdol Hossein; Fakheri, Rahman; Vazirinasab, Hamed; Daneshzadeh, Mohammad Taghi; Vojgani, Mahdi; Zomorodipour, Alireza; Fatemi, Nayeralsadat; Vahabi, Zeinab; Mirshahvaladi, Shahab; Ataei, Fariba; Bahraminejad, Elmira; Masoudi, Najmehsadat; Rezazadeh Valojerdi, Mojtaba; Gourabi, Hamid

2013-02-01

373

Dynamic T 1 studies of gadolinium uptake in brain tumors using LL-EPI  

Microsoft Academic Search

Using ultrafastT1 mapping (LL-EPI), the uptake from a bolus injection of Gd-DO3A (ProHance) into the sagittal sinus and a brain tumor has been monitored. The measurement of absoluteT1 removes the possible error in uptake curves created fromT1-weighted sequences caused by changes inT2* and simplifies the calculation of ProHance concentration. The LL-EPI sequence has an acquisition time of 1.2 s and

A. Freeman; P. Gowland; D. Jellineck; D. Wilcock; J. Firth; B. Worthington; P. Mansfield; G. Ratcliffe

1994-01-01

374

PAD2 Overexpression in Transgenic Mice Promotes Spontaneous Skin Neoplasia.  

PubMed

Peptidylarginine deiminase 2 (PAD2/PADI2) has been implicated in various inflammatory diseases and, more recently, cancer. The goal of this study was to test the hypothesis that PAD2 promotes oncogenesis using a transgenic mouse model. We found that about 37% of transgenic mice overexpressing human FLAG-PAD2 downstream of the MMTV-LTR promoter develop spontaneous neoplastic skin lesions. Molecular and histopathologic analyses of the resulting lesions find that they contain increased levels of markers for invasion, inflammation, and epithelial-to-mesenchymal transition (EMT) and that a subset of the lesions progress to invasive squamous cell carcinoma (SCC). We then stably overexpressed FLAG-PAD2 in the human SCC cell line, A431, and found that the PAD2-overexpressing cells were more tumorigenic in vitro and also contained elevated levels of markers for inflammation and EMT. Collectively, these studies provide the first genetic evidence that PAD2 functions as an oncogene and suggest that PAD2 may promote tumor progression by enhancing inflammation within the tumor microenvironment. Cancer Res; 74(21); 6306-17. ©2014 AACR. PMID:25213324

McElwee, John L; Mohanan, Sunish; Horibata, Sachi; Sams, Kelly L; Anguish, Lynne J; McLean, Dalton; Cvitaš, Iva; Wakshlag, Joseph J; Coonrod, Scott A

2014-11-01

375

Transgenic zebrafish model of neurodegeneration.  

PubMed

In Alzheimer's disease (AD), the microtubule-associated protein, tau, is compromised in its normal association with microtubules and forms into paired helical filaments (PHF) that are the hallmark cytoskeletal pathology of the disease. Several posttranslational modifications of tau including phosphorylation have been implicated in AD pathogenesis. In addition, and importantly, mutations in the genes encoding human tau have recently been implicated in a variety of hereditary dementias, collectively termed frontotemporal dementia with parkinsonism linked to chromosome 17 (FTDP-17). This has rekindled interest in the importance of tau in neurodegenerative diseases (cf. Vogel [1998] Science 280:1524-1525; Goedert et al. [1998] Neuron 21:955-958; D'Souza et al. [1999] PNAS 96:5598-5603). Despite significant progress in the field of tau biology and neurodegenerative diseases, several important issues remain unresolved. The early functional consequences of tau alterations in living neurons is incompletely understood, and it is not clear how tau in neurodegenerative diseases becomes redistributed from its normal concentration in neur