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1

Cryopreservation ofXenopus transgenic lines  

Microsoft Academic Search

Xenopus laevis has been widely used for molecular, cellular, and developmental studies. With the development of the sperm-mediated transgenic method, it is now possible to study gene function during vertebrate development by using this popular model. On the other hand, like other animal species, it is labor intensive, and the maintenance of transgenic lines is expensive. In this article, we

Daniel R. Buchholz; Liezhen Fu; Yun-Bo Shi

2004-01-01

2

Germ-line transmission of transgenes in Xenopus laevis  

PubMed Central

Adult Xenopus laevis frogs made transgenic by restriction enzyme-mediated integration were bred to test the feasibility of establishing lines of frogs that express transgenes. All of the 19 animals raised to sexual maturity generated progeny that expressed the transgene(s). The patterns and levels of expression of green fluorescent protein transgenes driven by a viral promoter, rat promoter, and four X. laevis promoters were all unaffected by passage through the germ line. These results demonstrate the ease of establishing transgenic lines in X. laevis.

Marsh-Armstrong, Nicholas; Huang, Haochu; Berry, Deborah L.; Brown, Donald D.

1999-01-01

3

Multiple ovarian transplants to rescue a transgenic line of mice  

Microsoft Academic Search

Transgenic mice are useful tools for studying gene function and regulation but can be difficult to successfully breed. To 'rescue' transgenic lines that are difficult to propagate, researchers use a variety of techniques. One method is ovarian transplant, in which researchers remove ovaries from a donor transgenic mouse, cryopreserve the ovarian tissue, transplant this tissue into histocompatible female mice and

Joyce Dawes; Bowen Liu; Wendy Mars; George Michalopoulos; Jaspal S. Khillan

2010-01-01

4

Insect management and herbicide tolerance in near-isogenic sister lines of transgenic and non-transgenic sweet corn  

Microsoft Academic Search

Pest management systems were evaluated in three near-isogenic lines of transgenic and non-transgenic sweet corn. The genetic transformation was reputed to confer resistance to corn earworm (Helicoverpa zea) and European corn borer (Ostrinia nubilalis), and increase tolerance to the herbicide glufosinate. Plots were planted with either a transgenic line or a non-transgenic sister line. Transgenic and non-transgenic varieties were treated

Douglas J. Doohan; Joel Felix; Jim Jasinski; Celeste Welty; Matthew D. Kleinhenz

2002-01-01

5

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

PubMed Central

We have studied the radiation dose responses of two human fibroblast lines: cells from a patient with Ataxia telangiectasia (AT-2SF) and an established line of human T-1 cells. Aerobic and hypoxic 225 kVp X-ray survival curves were used as controls to the heavy ion exposures. 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 microns-1 to over 1,000 keV microns-1. All Ataxia survival curves were exponential functions of the dose. Their radiosensitivity reached peak values at 100-200 keV microns-1. 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. At high LET their radiosensitivity approached that of the Ataxia cells. The repair-misrepair model has been used to interpret these results. According to this model, the molecular repair processes culminate either in eurepair or in misrepair. 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. 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. T-1 cells have efficient repair mechanisms at low LET, and the repair-misrepair model suggests that at high LET the T-1 cells can still efficiently repair individual lesions, but that as the lesions become closely spaced along the tracks, the probability of misrepair increases.

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

1984-01-01

6

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

7

A selectively terminable transgenic rice line expressing human lactoferrin.  

PubMed

Human lactoferrin (hLF) is a multifunctional milk protein which could be utilized for promoting human health. Transgenic rice has been used as a bioreactor for mass production of recombinant hLF. However, one major concern over such transgenic rice is the risk of its unintended spreading into environment and into our food supplies. Here we report the development of selectively terminable transgenic rice expressing human lactoferrin in seeds. These transgenic rice plants could be selectively terminated by bentazon, a common herbicide used for rice weed control. The hLF expression cassette was constructed into a T-DNA containing the RNA interference cassette suppressing the expression of the rice gene CYP81A6 which detoxifies herbicide bentazon, and the 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) cassette which confers to glyphosate tolerance. A transgenic line, named as G281, was identified for its high sensitivity to bentazon, high tolerance to glyphosate, and high expression of hLF. Southern analysis suggested G281 is a single copy insertion event. Field tests demonstrated that G281 plants can be completely killed by a single spray of bentazon at 1000 mg/L, which is safe to regular rice and represents only half of the dose recommended by manufacturer for rice field weed control. Therefore, any G281 contaminations in regular rice could be selectively terminated to make sure it will not enter food or feed supplies. PMID:20433928

Lin, Chaoyang; Nie, Peng; Lu, Wei; Zhang, Qing; Li, Jing; Shen, Zhicheng

2010-04-28

8

Generation and characterization of transgenic plum lines expressing gafp-1 with the bul409 promoter  

Technology Transfer Automated Retrieval System (TEKTRAN)

The Gastrodia anti fungal protein (GAFP-1) is a mannose-binding lectin that can confer increased disease resistance in transgenic tobacco and plum. In all previously-generated transgenic lines, the gene was under the control of the 35SCaMV promoter. In this study, transgenic plum lines were create...

9

Creation of Low-Copy Integrated Transgenic Lines in Caenorhabditis elegans  

Microsoft Academic Search

In Caenorhabditis elegans, transgenic lines are typically created by injecting DNA into the hermaphrodite germline to form multicopy extrachromosomal DNA arrays. This technique is a reliable means of expressing transgenes in C. elegans, but its use has limitations. Because extrachromosomal arrays are semistable, only a fraction of the animals in a transgenic extrachromosomal array line are transformed. In addition, because

Vida Praitis; Elizabeth Casey; David Collar; Judith Austin

10

Transgene expression enhancement in T-lymphoma cell lines.  

PubMed

In transfection protocols, the expression levels of the transgene is important to define, still is difficult to obtain in certain cell lines such as those derived from T-lymphoma cells. In this study we evaluate transgene expression kinetics in the presence and absence of two well known transcription activators such as phorbol-12-myristate13-acetate (PMA) and Ionomicin (IO). Three murine T lymphoma cell lines (LBC, EL4 and BW5147) were transfected by electroporation using green fluorescent protein (GFP) as a reporter gene and analyzed by flow cytometry. Addition of PMA/IO resulted in a significant increase of the Mean Fluorescence Intensity but not in GFP-positive cell percentages, either in transient or stable transfected LBC and EL4 cells. Remarkable, BW5147 cells showed low GFP induction with a significant increment only in stable transfected cells. Our results demonstrated that CMV promoter activity can be enhanced in transfected lymphoma cells by PMA/IO suggesting that transgene expression levels can be optimized by means of the use of transcription activators. PMID:16102518

Ruybal, Paula; Gravisaco, María José; Barcala, Virna; Escalada, Ana; Cremaschi, Graciela; Taboga, Oscar; Waldner, Claudia; Mongini, Claudia

2005-11-01

11

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.

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

12

Transgenic cell lines for detection of animal viruses.  

PubMed Central

Rapid diagnostic assays based on direct detection of viral antigen or nucleic acid are being used with increasing frequency in clinical virology laboratories. Virus culture, however, remains the only way to detect infectious virus and to analyze clinically relevant viral phenotypes, such as drug resistance. Growth of viruses in cell culture is labor intensive and time-consuming and requires the use of many different cell lines. Transgenic technology, together with increasing knowledge of the molecular pathways of virus replication, offers the possibility of using genetically modified cell lines to improve virus growth in cell culture and to facilitate detection of virus-infected cells. Genetically modifying cells so that they express a reporter gene only after infection with a specific virus can allow the detection of infectious virus by rapid and simple enzyme assays such as beta-galactosidase assays without the need for antibodies. Although transgenic cells have recently been successfully used for herpes simplex virus detection, much more work needs to be done to adapt this technology to other human viral pathogens such as cytomegalovirus and respiratory viruses. This review offers some strategies for applying this technology to a wide spectrum of animal viruses.

Olivo, P D

1996-01-01

13

Development of transgenic cotton lines expressing Allium sativum agglutinin (ASAL) for enhanced resistance against major sap-sucking pests.  

PubMed

Mannose-specific Allium sativum leaf agglutinin encoding gene (ASAL) and herbicide tolerance gene (BAR) were introduced into an elite cotton inbred line (NC-601) employing Agrobacterium-mediated genetic transformation. Cotton transformants were produced from the phosphinothricin (PPT)-resistant shoots obtained after co-cultivation of mature embryos with the Agrobacterium strain EHA105 harbouring recombinant binary vector pCAMBIA3300-ASAL-BAR. PCR and Southern blot analysis confirmed the presence and stable integration of ASAL and BAR genes in various transformants of cotton. Basta leaf-dip assay, northern blot, western blot and ELISA analyses disclosed variable expression of BAR and ASAL transgenes in different transformants. Transgenes, ASAL and BAR, were stably inherited and showed co-segregation in T1 generation in a Mendelian fashion for both PPT tolerance and insect resistance. In planta insect bioassays on T2 and T3 homozygous ASAL-transgenic lines revealed potent entomotoxic effects of ASAL on jassid and whitefly insects, as evidenced by significant decreases in the survival, development and fecundity of the insects when compared to the untransformed controls. Furthermore, the transgenic cotton lines conferred higher levels of resistance (1-2 score) with minimal plant damage against these major sucking pests when bioassays were carried out employing standard screening techniques. The developed transgenics could serve as a potential genetic resource in recombination breeding aimed at improving the pest resistance of cotton. This study represents the first report of its kind dealing with the development of transgenic cotton resistant to two major sap-sucking insects. PMID:24023750

Vajhala, Chakravarthy S K; Sadumpati, Vijaya Kumar; Nunna, Hariprasad Rao; Puligundla, Sateesh Kumar; Vudem, Dashavantha Reddy; Khareedu, Venkateswara Rao

2013-09-04

14

Toxicity assessment of transgenic papaya ringspot virus of 823-2210 line papaya fruits.  

PubMed

The transgenic papaya is a valuable strategy for creating plants resistant to papaya ringspot virus (PRSV) infection and increasing production. This study was further performed to evaluate the comparative toxicity effects of the newly developed transgenic line of the fruits of two backcross transgenic papaya lines (2210 and 823) and one hybrid line (823-2210) and compare to their parent non-transgenic (TN-2) counterparts. The stability analysis of coat protein (CP) of PRSV was investigated using the digestion stability assays in simulated gastric fluid (SGF), simulated intestinal fluid (SIF), and bile salts to detect the CP fragments. Results revealed that the CP fragments were rapidly hydrolyzed in SGF and were undetectable in organs and gastrointestinal contents in rats. For the genotoxicity, three in vitro assays were conducted and exhibited that non-transgenic and backcross transgenic papaya fruits were negative. Moreover, a repeated animal feeding study was conducted by feeding 2 g/kg of body weight (bw) of non-transgenic and backcross transgenic papaya fruits for 28 days in rats. There were no biological or toxicological significances between non-transgenic and backcross transgenic papaya fruits in rats. The results demonstrated that the backcross transgenic papaya fruit can be recognized as an equivalent substitution for traditional papaya in food safety. PMID:23350793

Lin, Hsin-Tang; Yen, Gow-Chin; Huang, Ting-Tzu; Chan, Lit-Fu; Cheng, Ying-Huey; Wu, Jhaol-Huei; Yeh, Shyi-Dong; Wang, Sheng-Yang; Liao, Jiunn-Wang

2013-02-07

15

Low-Z impurity visible line radiations in the IR-T1 tokamak  

Microsoft Academic Search

Summary form only given, as follows. Impurities emitted from the limiter and\\/or wall by the bombardment of plasma and hot neutral particles play an important role in tokamak discharges. The spectroscopic measurements of line emission are commonly used to evaluate the concentration, influx rate and power radiated by low-Z impurities. During the ohmic heating discharge, the quasi-stationary profiles of the

M. Ghorannevis; M. R. Salami; M. Masnavi

1997-01-01

16

Cre-mediated recombination efficiency and transgene expression patterns of three retinal bipolar cell-expressing Cre transgenic mouse lines  

PubMed Central

Purpose Retinal bipolar cells, comprising multiple types, play an essential role in segregating visual information into multiple parallel pathways in the retina. The ability to manipulate gene expression in specific bipolar cell type(s) in the retina is important for understanding the molecular basis of their normal physiological functions and diseases/disorders. The Cre/LoxP recombination system has become an important tool for allowing gene manipulation in vivo, especially with the increasing availability of cell- and tissue-specific Cre transgenic mouse lines. Detailed in vivo examination of the Cre/LoxP recombination efficiency and the transgene expression patterns for cell- and tissue-specific Cre transgenic mouse lines is essential for evaluating their utility. In this study, we investigated the Cre-mediated recombination efficiency and transgene expression patterns of retinal bipolar cell-expressing Cre transgenic lines by crossing with a Cre reporter mouse line and through Cre-dependent recombinant adeno-associated virus (rAAV) vector-mediated transgene delivery. Methods Three retinal bipolar cell-expressing Cre-transgenic mouse lines, 5-HTR2a-cre, Pcp2-cre, and Chx10-cre, were crossed with a strong Cre reporter mouse line that expresses a red fluorescent protein variant, tdTomato. rAAV2 vectors carrying a double-floxed inverted open-reading frame sequence encoding channelrhodopsin-2-mCherry (ChR2-mCherry) driven by a ubiquitous neuronal EF1? or a ubiquitous CMV promoter with a rAAV2 capsid mutation (Y444F) were injected into the intravitreal space of the eyes. Immunohistochemistry using retinal bipolar cell type–specific markers was performed to examine Cre-mediated recombination efficiency and the transgene expression patterns in bipolar cells in retinal whole mounts and vertical sections. Results For the 5-HTR2a-cre and Pcp2-cre mouse lines, the expression pattern of the Cre-mediated recombination by crossing the reporter line largely resembled the expression pattern of Cre. The bipolar cells showing Cre-mediated recombination in the 5-HTR2a-cre line and the Pcp2-cre line were predominantly type 4 cone bipolar cells and rod bipolar cells, respectively. For the Chx10-cre mouse line, the expression pattern of the Cre-mediated recombination by crossing the reporter line was different from that of Cre. The Cre-mediated transgene expression in retinal bipolar cells in the Chx10-cre line was not observed by crossing with the reporter mouse line but through Cre-dependent rAAV vector delivery. A rAAV2 vector with the combination of a CMV promoter and the Y444F capsid mutation achieved Cre-dependent transgene expression in retinal bipolar cells. Conclusions The retinal bipolar cell-expressing Cre-transgenic lines and the Cre-dependent rAAV vector reported in this study could be valuable tools for gene targeting and manipulation in retinal bipolar cells in mice.

Lu, Qi; Ganjawala, Tushar H.; Pan, Zhuo-Hua

2013-01-01

17

CCAAT/Enhancer-binding protein beta regulates expression of human T1R3 taste receptor gene in the bile duct carcinoma cell line, HuCCT1.  

PubMed

The T1R family (T1R1, T1R2 and T1R3 receptors) has a role in the detection of umami and sweet tastes in taste buds. Although T1R3 is also expressed in the intrahepatic bile duct, the expression patterns of T1R1 and T1R2 in this region have not been determined. In addition, the mechanisms of transcriptional regulation of the human T1R3 gene (Tas1r3) have not been elucidated. In this study, we determined the expression patterns of T1R2 and T1R3 in human liver and the function of C/EBPbeta in Tas1r3 promoter activity. Immunohistochemistry showed that T1R2 and T1R3 were expressed in the intrahepatic bile duct. 5'-RACE analysis revealed that the transcriptional start sites of Tas1r3 were located 67 bp and 176 bp upstream of the ATG. Promoter analysis of Tas1r3 was performed using the luciferase reporter assay and EMSA in the Tas1r3-expressing cell line, HuCCT1. The 226-bp region upstream of the ATG had promoter activity, and C/EBPbeta activated the Tas1r3 promoter activity in HuCCT1 cells. These results show that T1R2 and T1R3 receptors, in addition to their role in taste perception, may also have a role in intrahepatic cholangiocytes. C/EBPbeta was identified as the transcription factor regulating Tas1r3 promoter activity in HuCCT1 cells. PMID:17928076

Toyono, Takashi; Seta, Yuji; Kataoka, Shinji; Toyoshima, Kuniaki

2007-09-06

18

Tonin and Kallikrein in the Brain of Transgenic Rat Line Expressing Human Tissue Kallikrein  

Microsoft Academic Search

A transgenic rat line harboring the human tissue kallikrein gene was investigated for expression and activity of tonin and kallikrein in different regions of the brain. The introduction of the transgene into the rat genome produced a significant augmentation of the expression levels and activity of rat tissue kallikrein. The possibility that human kallikrein does not hydrolyze the rat substrate

Eliane S. L. Lomez; Ronaldo C. Araujo; Michael Bader; Joao B. Pesquero; Jorge L. Pesquero

2010-01-01

19

Rapid Production of Multiple Independent Lines of Fertile Transgenic Wheat (Triticum aestivum).  

PubMed Central

Improvement of wheat (Triticum aestivum) by biotechnological approaches is currently limited by a lack of efficient and reliable transformation methodology. In this report, we detail a protocol for transformation of a highly embryogenic wheat cultivar, Bobwhite. Calli derived from immature embryos, 0.5 to 1 mm long, were bombarded with microprojectiles coated with DNA containing as marker genes the bar gene, encoding phosphinothricin-resistance, and the gene encoding [beta]-glucuronidase (GUS), each under control of a maize ubiquitin promoter. The bombardment was performed 5 d after embryo excision, just after initiation of callus proliferation. The ability of plantlets to root in the presence of 1 or 3 mg/L of bialaphos was the most reliable selection criteria used to identify transformed plants. Stable transformation was confirmed by marker gene expression assays and the presence of the bar sequences in high molecular weight chromosomal DNA of the resultant plants. Nine independent lines of fertile transgenic wheat plants have been obtained thus far, at a frequency of 1 to 2 per 1000 embryos bombarded. On average, 168 d elapsed between embryo excision for bombardment and anthesis of the T0 plants. The transmission of both the resistance phenotype and bar DNA to the T1 generation verified that germline transformation had occurred.

Weeks, J. T.; Anderson, O. D.; Blechl, A. E.

1993-01-01

20

CD4-Specific Transgenic Expression of Human Cyclin T1 Markedly Increases Human Immunodeficiency Virus Type 1 (HIV-1) Production by CD4+ T Lymphocytes and Myeloid Cells in Mice Transgenic for a Provirus Encoding a Monocyte-Tropic HIV-1 Isolate  

PubMed Central

Human immunodeficiency virus type 1 (HIV-1)-encoded Tat provides transcriptional activation critical for efficient HIV-1 replication by interacting with cyclin T1 and recruiting P-TEFb to efficiently elongate the nascent HIV transcript. Tat-mediated transcriptional activation in mice is precluded by species-specific structural differences that prevent Tat interaction with mouse cyclin T1 and severely compromise HIV-1 replication in mouse cells. We investigated whether transgenic mice expressing human cyclin T1 under the control of a murine CD4 promoter/enhancer cassette that directs gene expression to CD4+ T lymphocytes and monocytes/macrophages (hu-cycT1 mice) would display Tat responsiveness in their CD4-expressing mouse cells and selectively increase HIV-1 production in this cellular population, which is infected primarily in HIV-1-positive individuals. To this end, we crossed hu-cycT1 mice with JR-CSF transgenic mice carrying the full-length HIV-1JR-CSF provirus under the control of the endogenous HIV-1 long terminal repeat and demonstrated that human cyclin T1 expression is sufficient to support Tat-mediated transactivation in primary mouse CD4 T lymphocytes and monocytes/macrophages and increases in vitro and in vivo HIV-1 production by these stimulated cells. Increased HIV-1 production by CD4+ T lymphocytes was paralleled with their specific depletion in the peripheral blood of the JR-CSF/hu-cycT1 mice, which increased over time. In addition, increased HIV-1 transgene expression due to human cyclin T1 expression was associated with increased lipopolysaccharide-stimulated monocyte chemoattractant protein 1 production by JR-CSF mouse monocytes/macrophages in vitro. Therefore, the JR-CSF/hu-cycT1 mice should provide an improved mouse system for investigating the pathogenesis of various aspects of HIV-1-mediated disease and the efficacies of therapeutic interventions.

Sun, Jinglin; Soos, Timothy; KewalRamani, Vineet N.; Osiecki, Kristin; Zheng, Jian Hua; Falkin, Laurie; Santambrogio, Laura; Littman, Dan R.; Goldstein, Harris

2006-01-01

21

Creation of low-copy integrated transgenic lines in Caenorhabditis elegans.  

PubMed Central

In Caenorhabditis elegans, transgenic lines are typically created by injecting DNA into the hermaphrodite germline to form multicopy extrachromosomal DNA arrays. This technique is a reliable means of expressing transgenes in C. elegans, but its use has limitations. Because extrachromosomal arrays are semistable, only a fraction of the animals in a transgenic extrachromosomal array line are transformed. In addition, because extrachromosomal arrays can contain hundreds of copies of the transforming DNA, transgenes may be overexpressed, misexpressed, or silenced. We have developed an alternative method for C. elegans transformation, using microparticle bombardment, that produces single- and low-copy chromosomal insertions. Using this method, we find that it is possible to create integrated transgenic lines that reproducibly express GFP reporter constructs without the variations in expression level and pattern frequently exhibited by extrachromosomal array lines. In addition, we find that low-copy integrated lines can also be used to express transgenes in the C. elegans germline, where conventional extrachromosomal arrays typically fail to express due to germline silencing.

Praitis, V; Casey, E; Collar, D; Austin, J

2001-01-01

22

Enhanced resistance to early blight in transgenic tomato lines expressing heterologous plant defense genes.  

PubMed

Genes coding for an iris ribosomal-inactivating protein (I-RIP), a maize beta-glucanase (M-GLU), and a Mirabilis jalapa antimicrobial peptide (Mj-AMP1) were separately introduced into tomato (Lycopersicon esculentum cv. Sweet Chelsea) cotyledons via Agrobacterium tumefaciens-mediated transformation. Transgenic lines carrying each of the transgenes were confirmed for integration into the tomato genome using Southern blot hybridization. Transcription of I-RIP, M-GLU, and Mj-AMP1 genes in various transgenic lines was determined using Northern blot analysis. Plants of selected transgenic lines were inoculated with a 2-3x10(4) conidial spores/ml suspension of the fungal pathogen Alternaria solani, the causal agent of tomato early blight. Compared to control (non-transformed) plants, two transgenic lines carrying either a M-GLU or Mj-AMP1 showed enhanced resistance to early blight disease. None of the four lines carrying the I-RIP transgene showed increased resistance to early blight. PMID:16047198

Schaefer, Scott C; Gasic, Ksenija; Cammue, Bruno; Broekaert, Willem; van Damme, Els J M; Peumans, Willy J; Korban, Schuyler S

2005-07-27

23

Differences of globin transgene expression in stably transfected cell lines and transgenic mice  

PubMed Central

Previous studies demonstrated that DNase I hypersensitive site ?40 (HS-40) of the ?-globin locus is capable of greatly enhancing expression of a hybrid ?/?-globin transcriptional unit in plasmid-transfected murine erythroleukemia (MEL) cells. However, as reported here, this same ?-globin gene expression cassette was only transcribed at trace amounts in erythroid cells of transgenic mice. This lack of expression was not directly attributable to the ?/?-globin transcriptional unit, since this same unit linked to a composite ?-globin locus control region was expressed at high levels in transgenic mice. This lack of expression was also not directly attributable to chromosomal position effects, since addition of chromatin insulators failed to increase the frequency of expression. DNase I hypersensitivity and chromatin immunoprecipitation assays demonstrated that the lack of expression was correlated with a closed chromatin structure. We hypothesize that transgenes undergo dynamic changes in chromatin conformation following chromosomal integration and that the discrepant results reported here can be attributed to the relatively high level of chromatin remodeling that occurs in the transgenic mouse model, coupled with the relative inability of the HS-40 element to maintain an open chromatin state under such conditions.

Li, Qiliang; Emery, David W.; Han, Hemei; Sun, Jin; Yu, Man; Stamatoyannopoulos, George

2010-01-01

24

Partial Resistance to White Mold in a Transgenic Soybean Line  

Microsoft Academic Search

small effects, each explaining 10% or less of the varia- tion, making breeding with these loci difficult. Oxalic acid is an important pathogenic factor for the fungus Sclero- Most infections of soybean by S. sclerotiorum origi- tinia sclerotiorum (Lib.) de Bary. An oxalate degrading enzyme, oxalate nate from colonization of flower petals by airborne asco- oxidase (OxO), in transgenic soybean

Elroy R. Cober; Sylvie Rioux; Istvan Rajcan; Pauline A. Donaldson; Daina H. Simmonds

2003-01-01

25

Live image profiling of neural crest lineages in zebrafish transgenic lines.  

PubMed

Zebrafish transgenic lines are important experimental tools for lineage tracing and imaging studies. It is crucial to precisely characterize the cell lineages labeled in transgenic lines to understand their limitations and thus properly interpret the data obtained from their use; only then can we confidently select a line appropriate for our particular research objectives. Here we profiled the cell lineages labeled in the closely related neural crest transgenic lines Tg(foxd3:GFP), Tg(sox10:eGFP) and Tg(sox10:mRFP). These fish were crossed to generate embryos, in which foxd3 and sox10 transgenic neural crest labeling could be directly compared at the cellular level using live confocal imaging. We have identified key differences in the cell lineages labeled in each line during early neural crest development and demonstrated that the most anterior cranial neural crest cells initially migrating out of neural tube at the level of forebrain and anterior midbrain express sox10:eGFP and sox10:mRFP, but not foxd3:GFP. This differential profile was robustly maintained in the differentiating progeny of the neural crest lineages until 3.5dpf. Our data will enable researchers to make an informed choice in selecting transgenic lines for future neural crest research. PMID:23456294

Kwak, Jina; Park, Ok Kyu; Jung, Yoo Jung; Hwang, Byung Joon; Kwon, Seung-Hae; Kee, Yun

2013-02-26

26

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

27

Derivation of a germline competent transgenic Fischer 344 embryonic stem cell line.  

PubMed

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

2013-02-20

28

Transposon-mediated Chromosomal Integration of Transgenes in the Parasitic Nematode Strongyloides ratti and Establishment of Stable Transgenic Lines  

PubMed Central

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.

Nolan, Thomas J.; Massey, Holman C.; Pearce, Edward J.; Lok, James B.

2012-01-01

29

Biosafety Assessment of Site-directed Transgene Integration in Human Umbilical Cord-lining Cells  

PubMed Central

Biosafety and efficacy considerations that impede clinical application of gene therapy could be addressed by nonviral ex vivo cell therapy, utilizing transgenic cells that have been comprehensively pre-evaluated for genotoxic potential and transgene expression. We evaluated the genotoxic potential of phiC31 bacteriophage integrase-mediated transgene integration in cord-lining epithelial cells (CLECs) readily cultured from the outer membrane of human umbilical cords, by sequencing and mapping integration sites, spectral karyotyping, high-resolution genome copy number, transcriptome, and transgene copy number analyses and in vivo tumorigenicity. Of 44 independent integration events, <5% were exonic and 85% of modified cells had integrated ?2 transgene(s). Expression of 95.6% of genes was unaltered in modified cells. Only three small regions showed genome copy number changes that did not correlate with altered gene expression or integration sites. Spectral karyotyping revealed rare nonrecurrent occurrence of three different translocations. Integrase-modified cells were not tumorigenic in immunocompromised mice for at least 4 months. Stable integration of a human factor VIII (FVIII) construct conferred durable FVIII secretion in vitro. Xenoimplantation of FVIII-secreting CLECs in immunocompetent hemophilic mice achieved significant phenotypic correction. Pre-evaluated clonal populations of phiC31 integrase–modified CLECs could be useful as bioimplants for monogenic diseases such as hemophilia.

Sivalingam, Jaichandran; Krishnan, Shruti; Ng, Wai Har; Lee, Sze Sing; Phan, Toan Thang; Kon, Oi Lian

2010-01-01

30

FIELD REACTION TO SCLEROTINIA BLIGHT AMONG TRANSGENIC PEANUT LINES CONTAINING ANTIFUNGAL GENES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Peanut (Arachis hypogaea L.) is susceptible to many diseases. In the Southwestern U.S. and other regions where peanut is grown, diseases caused by fungi are a major threat to profitable production. Transgenic peanut lines possessing fungal resistance genes offer an alternative to traditional resis...

31

lambda 5, but not mu, is required for B cell maturation in a unique gamma 2b transgenic mouse line  

PubMed Central

gamma 2b transgenic mice have a severe B cell defect, apparently caused by strong feedback inhibition of endogenous H-gene rearrangement coupled with an inability of gamma 2b to provide the survival/maturation functions of mu. A unique gamma 2b transgenic line, named the C line, was found to permit B cell development. When the C line is crossed with a mu-membrane knockout line, gamma 2b+ B cells develop in the homozygous knockout. In contrast, a transgenic line representative of all the other gamma 2b lines is completely B cell deficient when mu-mem is deleted. Strikingly, the C phenotype is dominant in C x other gamma 2b transgenic line crosses. There is no evidence for higher gamma 2b transgene expression or other position effects on the transgene in the C mouse. The sequences of the three gamma 2b transgene copies in the C line are identical to that of the original transgene. These results have led to the conclusion that in the C line the transgene integration constitutively induces a gene whose expression can replace mu. To more clearly delineate the stage at which the altered phenotype of the C line is expressed, C mice were crossed onto a lambda 5 knockout background. In the absence of lambda 5, the C line produces no B cells. Since it was also found that gamma 2b can associate with the surrogate light chain (sL; lambda 5/Vpre-B), the crosses between C line gamma 2b mice and lambda 5 knockout mice suggest that gamma 2b/sL is required for B cell maturation in this mouse line. Thus, gamma 2b alone is unable to replace mu for pre-B cell survival/maturation; however, in combination with an unknown factor and the sL, gamma 2b can provide these nurturing functions.

1995-01-01

32

A transgenic insect cell line engineered to produce CMP-sialic acid and sialylated glycoproteins  

PubMed Central

We have previously engineered transgenic insect cell lines to express mammalian glycosyltransferases and showed that these cells can sialylate N-glycoproteins, despite the fact that they have little intracellular sialic acid and no detectable CMP–sialic acid. In the accompanying study, we presented evidence that these cell lines can salvage sialic acids for de novo glycoprotein sialylation from extracellular sialogly-coproteins, such as fetuin, found in fetal bovine serum. This finding led us to create a new transgenic insect cell line designed to synthesize its own sialic acid and CMP–sialic acid. SfSWT-1 cells, which encode five mammalian glycosyltransferases, were transformed with two additional mammalian genes that encode sialic acid synthase and CMP–sialic acid synthetase. The resulting cell line expressed all seven mammalian genes, produced CMP–sialic acid, and sialylated a recombinant glycoprotein when cultured in a serum-free growth medium supplemented with N-acetylmannosamine. Thus the addition of mammalian genes encoding two enzymes involved in CMP–sialic acid biosynthesis yielded a new transgenic insect cell line, SfSWT-3, that can sialylate recombinant glycoproteins in the absence of fetal bovine serum. This new cell line will be widely useful as an improved host for baculovirus-mediated recombinant glycoprotein production.

Aumiller, Jared J.; Hollister, Jason R.; Jarvis, Donald L.

2013-01-01

33

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.

Smith, Ryan C.

2010-01-01

34

Morphological alterations in retinal neurons in the S334ter-line3 transgenic rat  

Microsoft Academic Search

The S334ter-line-3 rat is a transgenic model of retinal degeneration developed to express a rhodopsin mutation similar to\\u000a that found in human retinitis pigmentosa (RP) patients. Previous studies have focused on physiological changes in retinal\\u000a cells and higher centers of the visual system with this model of retinal degeneration. However, little is known about the\\u000a morphological changes in retinal cells

Aditi Ray; Gerald J. Sun; Leanne Chan; Norberto M. Grzywacz; James Weiland; Eun-Jin Lee

2010-01-01

35

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

36

Neurobehavioral development of two mouse lines commonly used in transgenic studies  

Microsoft Academic Search

The present study was aimed at establishing the differences in the neurodevelopmental profile between two F2 lines derived from two F1 hybrid mouse strains (129×C57BL\\/6 and C57BL\\/6×SJL). The choice of the given strains was based on the frequent use of these mice in transgenic research. For the neurodevelopment phenotyping, we employed a test battery consisting of 23 somatometric, sensorial and

M. Dierssen; V. Fotaki; M. Mart??nez de Lagrán; M. Gratacós; M. Arbonés; C. Fillat; X. Estivill

2002-01-01

37

Strain and gender differences in the behavior of mouse lines commonly used in transgenic studies  

Microsoft Academic Search

The present study was aimed at establishing behavioral differences between three inbred mouse strains (129S2\\/SvHsd, C57BL\\/6JOlaHsd, FVB\\/NHsd) and two F1 hybrid lines derived from them (129×C57BL\\/6 and 129×FVB). The choice of the given strains was based on the frequent use of these mice in transgenic research. For the behavioral phenotyping, we employed a test battery consisting of the following models:

Vootele Vőikar; Sulev Kőks; Eero Vasar; Heikki Rauvala

2001-01-01

38

Proteomic analysis of livers from a transgenic mouse line with activated polyamine catabolism.  

PubMed

We have generated a transgenic mouse line that over expresses the rate-controlling enzyme of the polyamine catabolism, spermidine/spermine N (1)-acetyltransferase, under the control of a heavy metal inducible promoter. This line is characterized by a notable increase in SSAT activity in liver, pancreas and kidneys and a moderate increase in the rest of the tissues. SSAT induction results in an enhanced polyamine catabolism manifested as a depletion of spermidine and spermine and an overaccumulation of putrescine in all tissues. To study how the activation of polyamine catabolism affects other metabolic pathways, protein expression pattern of the livers of transgenic animals was analyzed by two-dimensional polyacrylamide gel electrophoresis and mass spectrometry. A total of 23 proteins were shown to be differentially expressed in the transgenic from the wild-type animals. Many of the identified proteins showed expression patterns associated with polyamine catabolism activation. However, the expression pattern of other proteins, such as repression of GST pi and selenium-binding protein 2 and 60 kDa heat-shock protein, could be explained by the overexpression of peroxisome proliferator-activated receptor gamma co-activator 1alpha in response to depleted ATP pools. The activation of the latter proteins is thought to lead to the improved insulin sensitivity seen in the MT-SSAT animals. PMID:20012117

Cerrada-Gimenez, Marc; Häyrinen, Jukka; Juutinen, Sisko; Reponen, Tuula; Jänne, Juhani; Alhonen, Leena

2009-12-10

39

Burial and seed survival in Brassica napus subsp. oleifera and Sinapis arvensis including a comparison of transgenic and non-transgenic lines of the crop  

Microsoft Academic Search

SUMMARY The creation of transgenic plants through genetic engineering has focused interest on how the fitness of a plant species may be altered by small changes in its genome. This study concentrates on a key component of fitness: persistence of seeds overwinter. Seeds of three lines of oilseed rape (Brassica napus subsp. oleifera DC Metzger) and of charlock (Sinapis aräensis

R. S. Hails; M. Rees; D. D. Kohn; M. J. Crawley

1997-01-01

40

Characterization of transgenic mouse lines expressing Cre-recombinase in the retina  

PubMed Central

The mammalian retina consists of five major classes of neuronal cells, as well as glial cells, and it contains more than 50 cell types. The ability to manipulate gene expression in specific cell type(s) in the retina is important for understanding the molecular mechanisms of retinal function and diseases. The Cre/loxP recombination system has been shown to be a powerful tool, allowing gene deletion, over-expression, and ectopic expression in vivo in a cell- and tissue-specific fashion. The key to this tool is the availability of Cre mouse lines with cell- or tissue-type specific expression of Cre recombinase. To date, a large number of Cre-transgenic mouse lines have been generated to target Cre recombinase expression to specific neuronal and glial cell populations in the CNS; however, information about the expression patterns of Cre recombinase lines in the retina is largely lacking. In this study, we examined and characterized the expression patterns of Cre recombinase in the retinas of 15 Cre-transgenic mouse lines. Significant Cre-induced recombination or expression of Cre recombinase was observed in the majority of these lines. In particular, we found several Cre lines in which the Cre-induced recombination was found to target exclusively or predominantly a single type or class of retinal cells, including bistratified retinal ganglion cells, starburst amacrine cells, rod bipolar cells, and Müller glial cells. In other lines, the Cre-induced recombination was found in several retinal cell types. These Cre lines provide a valuable resource for retinal research.

Ivanova, Elena; Hwang, Grace-Soon; Pan, Zhuo-Hua

2009-01-01

41

A transgenic medaka line with visible markers for genotypic and phenotypic sex.  

PubMed

Accurate genotyping of sex is required for correct interpretation in any in vivo assays with endocrine disrupting chemicals (EDCs). Visible markers for genotypic sex, if reliable, simplify assays because time-consuming PCR-based genotyping can be skipped. Here, we describe a line of Japanese medaka with a brain-expressed green fluorescent protein (GFP) transgene inserted near the sex-determining locus. When used with a white pigment cell marker, genotypic sex can be determined reliably as early as 3 days after fertilization (well before gonadal sex differentiation). No recombinants were found in more than 2000 progenies. We also introduced a strong ovarian GFP marker into the line with these genetic sex markers, so that phenotypic sex can also be determined reliably at 8 days after hatching. Well-known sex reversal protocols using exogenous steroid treatments of embryos were monitored by this transgenic line, demonstrating the line to be a useful tool for in vivo studies utilizing gonadal sex differentiation of the medaka, especially for screenings of potential estrogenic and androgenic EDCs. PMID:23638909

Kanamori, Akira; Toyama, Keiko

2013-05-29

42

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

2012-10-18

43

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.

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

2002-01-01

44

Transgenic rose lines harboring an antimicrobial protein gene, Ace-AMP1, demonstrate enhanced resistance to powdery mildew ( Sphaerotheca pannosa).  

PubMed

An antimicrobial protein gene, Ace-AMP1, was introduced into Rosa hybrida cv. Carefree Beauty via Agrobacterium-mediated transformation. A total of 500 putative transgenic plants were obtained from 100 primary embryogenic calli co-cultivated with A. tumefaciens following selection on a regeneration medium containing 100 mg/l kanamycin. Polymerase chain reaction analysis of these putative transgenic lines, using primers for both Ace-AMP1 and neomycin phosphotransferase ( npt II) genes, showed that 62% of these plants were positive for both transgenes. These lines were further confirmed for stable integration of Ace-AMP1 and npt II genes by Southern blotting. Transcription of the Ace-AMP1 transgene in various transgenic rose lines was determined using Northern blotting. Transgenic rose lines inoculated with conidial spores of Sphaerotheca pannosa (Wallr.: Fr.) Lev. var. rosae showed enhanced resistance to powdery mildew using both a detached-leaf assay and an in vivo greenhouse whole-plant assay. PMID:14508687

Li, Xiangqian; Gasic, Ksenjia; Cammue, Bruno; Broekaert, Willem; Korban, Schuyler S

2003-09-24

45

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

PubMed Central

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.

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

2012-01-01

46

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

2012-02-13

47

Modified expression of cysteine protease affects seed germination, vegetative growth and nodule development in transgenic lines of Medicago truncatula  

Microsoft Academic Search

Transgenic lines of Medicago truncatula (R108-1) were constructed to analyse Cyp15a (cysteine protease) gene functioning and localisation. The promoter region of PsCyp15a was fused to the coding sequence of uidA. GUS-analysis of transgenic plants containing this construct revealed strong expression from the Cyp15 promoter in cotyledonary leaves, senescent leaves, and root nodules. A seven-fold increase in GUS activity was observed

S. Sheokand; P. Dahiya; J. L. Vincent; N. J. Brewin

2005-01-01

48

Germ-line transmission of lentiviral PGK-EGFP integrants in transgenic cattle: new perspectives for experimental embryology  

Microsoft Academic Search

Lentiviral vectors are a powerful tool for the genetic modification of livestock species. We previously generated transgenic\\u000a founder cattle with lentiviral integrants carrying enhanced green fluorescent protein (EGFP) under the control of the phosphoglycerate\\u000a kinase (PGK) promoter. In this study, we investigated the transmission of LV-PGK-EGFP integrants through the female and male\\u000a germ line in cattle. A transgenic founder heifer

Myriam Reichenbach; Tiongti Lim; Horst-Dieter Reichenbach; Tuna Guengoer; Felix A. Habermann; Marieke Matthiesen; Andreas Hofmann; Frank Weber; Holm Zerbe; Thomas Grupp; Fred Sinowatz; Alexander Pfeifer; Eckhard Wolf

2010-01-01

49

Characterization of Prostatic Epithelial Cell Lines Derived from Transgenic Adenocarcinoma of the Mouse Prostate (TRAMP) Model1  

Microsoft Academic Search

To develop a syngeneic transplantablesystem to study immunothera peutic approaches for the treatment of prostate cancer, three cell lines were established from a heterogeneous 32 week tumor of the t@ansgenic adenocarcinoma g@ouseprostate (TRAMP) modeL TRAMP is a transgenic line of C57B116 mice harboring a construct comprised of the minimal â€\\

Barbara A. Foster; Jeffrey R. Gingrich; Eugene D. Kwon; Christopher Madias; Norman M. Greenberg

50

RE-ESTABLISHMENT OF A TRANSGENIC CHICKEN LINE 0-ALV6 AT THE AVIAN DISEASE AND ONCOLOGY LABORATORY  

Technology Transfer Automated Retrieval System (TEKTRAN)

The first transgenic chicken line, 0.ALV6, was produced at the Avian Disease and Oncology Laboratory (ADOL) in 1989. Blastoderms of fertile freshly laid line 0 eggs were injected with the long terminal repeats of the endogenous Rous-associated virus (RAV-0) and the envelope gene (env) of a subgroup ...

51

The transposition frequency of Tag1 elements is increased in transgenic Arabidopsis lines.  

PubMed Central

Tag1 was identified as a highly active endogenous transposable element in transgenic Arabidopsis thaliana Landsberg erecta plants carrying the maize transposable element Activator (Ac). Here, we describe experiments designed to determine the basis for the high activity of Tag1. The frequency of transposition of Tag1 elements was compared in lines containing or lacking Ac transposase to assess the effect of Ac transposase on Tag1 activity. Three populations of nontransgenic plants, including nontransformed regenerants, were also analyzed. The high level of activity of Tag1 did not correlate with the presence or absence of Ac transposase but was significantly higher in transgenic lines. This result was maintained through at least six generations after transformation. These data suggest that Tag1 transposition is stimulated by processes that occur during the Agrobacterium transformation and that thereafter remain active. Two Tag1 elements are tightly linked in the Landsberg erecta genome and map to the lower arm of chromosome 1. Tag1 elements were found in only a few A. thaliana ecotypes but were present in four other Arabidopsis species.

Bhatt, A M; Lister, C; Crawford, N; Dean, C

1998-01-01

52

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.

2012-01-01

53

Putrescine accumulation in Arabidopsis thaliana transgenic lines enhances tolerance to dehydration and freezing stress  

PubMed Central

Polyamines have been globally associated to plant responses to abiotic stress. Particularly, putrescine has been related to a better response to cold and dehydration stresses. It is known that this polyamine is involved in cold tolerance, since Arabidopsis thaliana plants mutated in the key enzyme responsible for putrescine synthesis (arginine decarboxilase, ADC; EC 4.1.1.19) are more sensitive than the wild type to this stress. Although it is speculated that the overexpression of ADC genes may confer tolerance, this is hampered by pleiotropic effects arising from the constitutive expression of enzymes from the polyamine metabolism. Here, we present our work using A. thaliana transgenic plants harboring the ADC gene from oat under the control of a stress-inducible promoter (pRD29A) instead of a constitutive promoter. The transgenic lines presented in this work were more resistant to both cold and dehydration stresses, associated with a concomitant increment in endogenous putrescine levels under stress. Furthermore, the increment in putrescine upon cold treatment correlates with the induction of known stress-responsive genes, and suggests that putrescine may be directly or indirectly involved in ABA metabolism and gene expression.

Alet, Analia I; Sanchez, Diego H; Cuevas, Juan C; del Valle, Secundino; Altabella, Teresa; Tiburcio, Antonio F; Marco, Francisco; Ferrando, Alejandro; Espasandin, Fabiana D; Gonzalez, Maria E; Carrasco, Pedro

2011-01-01

54

Effect of transgenic Bacillus thuringiensis rice lines on mortality and feeding behavior of rice stem borers (Lepidoptera: Crambidae).  

PubMed

Ten transgenic Bacillus thuringiensis Bt rice, Oryza sativa L., lines with different Bt genes (two Cry1Ac lines, three Cry2A lines, and five Cry9C lines) derived from the same variety Minghui 63 were evaluated in both the laboratory and the field. Bioassays were conducted by using the first instars of two main rice lepidopteran insect species: yellow stem borer, Scirpophaga incertulas (Walker) and Asiatic rice borer, Chilo suppressalis (Walker). All transgenic lines exhibited high toxicity to these two rice borers. Field evaluation results also showed that all transgenic lines were highly insect resistant with both natural infestation and manual infestation of the neonate larvae of S. incertulas compared with the nontransformed Minghui63. Bt protein concentrations in leaves of 10 transgenic rice lines were estimated by the sandwich enzyme-linked immunosorbent assay. The cry9C gene had the highest expression level, next was cry2A gene, and the cry1Ac gene expressed at the lowest level. The feeding behavior of 7-d-old Asiatic rice borer to three classes of Bt transgenic rice lines also was detected by using rice culm cuttings. The results showed that 7-d-old larvae of Asiatic rice borer have the capacity to distinguish Bt and non-Bt culm cuttings and preferentially fed on non-Bt cuttings. When only Bt culm cuttings with three classes of different Bt proteins (CrylAc, Cry2A, and Cry9C) were fed, significant distribution difference of 7-d-old Asiatic rice borer in culm cuttings of different Bt proteins also was found. In the current study, we evaluate different Bt genes in the same rice variety in both the laboratory and the field, and also tested feeding behavior of rice insect to these Bt rice. These data are valuable for the further development of two-toxin Bt rice and establishment of appropriate insect resistance management in the future. PMID:18330134

Chen, Hao; Zhang, Guoan; Zhang, Qifa; Lin, Yongjun

2008-02-01

55

Transgenic Chinese hamster V79 cell lines which exhibit variable levels of gpt mutagenesis  

SciTech Connect

The Escherichia coli gpt gene coding for xanthine-guanine phosphoribosyl transferase has been stably transfected into HPRT{sup {minus}} Chinese hamster V79 cells. Several gpt{sup {minus}} cell lines have been established, which retain the sequence(s) even after long-term culture without selection for gpt. While spontaneous mutagenesis to gpt{sup {minus}} occurs rather frequently for most cell lines, it cannot be correlated with either the number of plasmid integration sites or deletion of the plasmid sequence(s). One transgenic cell line (g12), which continuously maintains a low spontaneous mutation frequency was used in comparative mutagenesis studies with wild-type V79 cells (gpt vs. hprt). Alkylating agents such as N-methyl-N{prime}-nitro-N-nitrosoguanidine (MNNG) and {beta}-propiolactone (BPL) are shown to be equally toxic and mutagenic in both g12 and V79 cells. UV and X-rays are also equally toxic to both cell lines. The data presented here suggests that g12 cells may be useful to study mammalian mutagenesis by agents which yield limited response at the hprt locus.

Klein, C.B.; Rossman, T.G. (New York Univ. Medical Center, New York (USA))

1990-01-01

56

De novo piRNA cluster formation in the Drosophila germ line triggered by transgenes containing a transcribed transposon fragment  

PubMed Central

PIWI-interacting RNAs (piRNAs) provide defence against transposable element (TE) expansion in the germ line of metazoans. piRNAs are processed from the transcripts encoded by specialized heterochromatic clusters enriched in damaged copies of transposons. How these regions are recognized as a source of piRNAs is still elusive. The aim of this study is to determine how transgenes that contain a fragment of the Long Interspersed Nuclear Elements (LINE)-like I transposon lead to an acquired TE resistance in Drosophila. We show that such transgenes, being inserted in unique euchromatic regions that normally do not produce small RNAs, become de novo bidirectional piRNA clusters that silence I-element activity in the germ line. Strikingly, small RNAs of both polarities are generated from the entire transgene and flanking genomic sequences—not only from the transposon fragment. Chromatin immunoprecipitation analysis shows that in ovaries, the trimethylated histone 3 lysine 9 (H3K9me3) mark associates with transgenes producing piRNAs. We show that transgene-derived hsp70 piRNAs stimulate in trans cleavage of cognate endogenous transcripts with subsequent processing of the non-homologous parts of these transcripts into piRNAs.

Olovnikov, Ivan; Ryazansky, Sergei; Shpiz, Sergey; Lavrov, Sergey; Abramov, Yuri; Vaury, Chantal; Jensen, Silke; Kalmykova, Alla

2013-01-01

57

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

2013-01-21

58

[Developing transgenic barley lines producing human lactoferrin using mutant alfa-tubulin gene as selective marker gene].  

PubMed

Method of biolistic transformation was used for genetic improvement of commercial barley cultivars (Oksamitoviy, Vodogray and Getman). The plasmid pHLFTuBA was used for particle bombardment that consists of the hLF gene under the control of the barley glutelin B-1 promoter and a selectable marker gene, alpha-tubulin conferring resistance to trifluralin (dinitroanilinr herbicide). Preliminary screening of different trifluralin concentration range from 0,1 to 30 microM was tested for determination of effective selective agent concentration. Two transgenic barley line of genotype Oksamitiviy and transgenic callus line of cultivar Getman were obtained after selection on 10 microM of trifluralin. To confirm the transgenic nature of regenerated plants, the PCR analysis was carried out. The 734bp length fragment of hLFgene was amplified from both regenerated plants. PMID:21446153

Tanasienko, I V; Emets, A I; Pirko, Ia V; Korkhovo?, V I; Abumkhadi, N; Blium, Ia B

59

Use of the piggyBac transposon to create HIV-1 gag transgenic insect cell lines for continuous VLP production  

PubMed Central

Background Insect baculovirus-produced Human immunodeficiency virus type 1 (HIV-1) Gag virus-like-particles (VLPs) stimulate good humoral and cell-mediated immune responses in animals and are thought to be suitable as a vaccine candidate. Drawbacks to this production system include contamination of VLP preparations with baculovirus and the necessity for routine maintenance of infectious baculovirus stock. We used piggyBac transposition as a novel method to create transgenic insect cell lines for continuous VLP production as an alternative to the baculovirus system. Results Transgenic cell lines maintained stable gag transgene integration and expression up to 100 cell passages, and although the level of VLPs produced was low compared to baculovirus-produced VLPs, they appeared similar in size and morphology to baculovirus-expressed VLPs. In a murine immunogenicity study, whereas baculovirus-produced VLPs elicited good CD4 immune responses in mice when used to boost a prime with a DNA vaccine, no boost response was elicited by transgenically produced VLPs. Conclusion Transgenic insect cells are stable and can produce HIV Pr55 Gag VLPs for over 100 passages: this novel result may simplify strategies aimed at making protein subunit vaccines for HIV. Immunogenicity of the Gag VLPs in mice was less than that of baculovirus-produced VLPs, which may be due to lack of baculovirus glycoprotein incorporation in the transgenic cell VLPs. Improved yield and immunogenicity of transgenic cell-produced VLPs may be achieved with the addition of further genetic elements into the piggyBac integron.

2010-01-01

60

Transgene expression of green fluorescent protein and germ line transmission in cloned pigs derived from in vitro transfected adult fibroblasts.  

PubMed

The pig represents the xenogeneic donor of choice for future organ transplantation in humans for anatomical and physiological reasons. However, to bypass several immunological barriers, strong and stable human genes expression must occur in the pig's organs. In this study we created transgenic pigs using in vitro transfection of cultured cells combined with somatic cell nuclear transfer (SCNT) to evaluate the ubiquitous transgene expression driven by pCAGGS vector in presence of different selectors. pCAGGS confirmed to be a very effective vector for ubiquitous transgene expression, irrespective of the selector that was used. Green fluorescent protein (GFP) expression observed in transfected fibroblasts was also maintained after nuclear transfer, through pre- and postimplantation development, at birth and during adulthood. Germ line transmission without silencing of the transgene was demonstrated. The ubiquitous expression of GFP was clearly confirmed in several tissues including endothelial cells, thus making it a suitable vector for the expression of multiple genes relevant to xenotransplantation where tissue specificity is not required. Finally cotransfection of green and red fluorescence protein transgenes was performed in fibroblasts and after nuclear transfer blastocysts expressing both fluorescent proteins were obtained. PMID:18823265

Brunetti, Dario; Perota, Andrea; Lagutina, Irina; Colleoni, Silvia; Duchi, Roberto; Calabrese, Fiorella; Seveso, Michela; Cozzi, Emanuele; Lazzari, Giovanna; Lucchini, Franco; Galli, Cesare

2008-12-01

61

Transimmortalized proximal tubule and collecting duct cell lines derived from the kidneys of transgenic mice.  

PubMed

This review summarizes the strategy of cellular immortalization based on the principle of targeted oncogenesis in transgenic mice, used to establish models of transimmortalized renal proximal tubule cells, referred to as PKSV-PCT and PKSV-PR-cells, and collecting duct principal cells, referred to as mpkCCD(cl4) cells. These cell lines have maintained for long-term passages the main biochemical and functional properties of the parental cells from which they were derived. Proximal tubule PKSV-PCT and PKSV-PR cells have been proved to be suitable cell systems for toxicological and pharmacological studies. They also permitted the establishment of a model of multidrug-resistant (MDR) renal epithelial tubule cells, PKSV-PR(col50), which have served for the study of both MDR-dependent extrusion of chemotherapeutic drugs and inappropriate accumulation of weak base anthracyclines in intracellular acidic organelles. The novel collecting duct cell line mpkCCD(cl4), which has maintained the characteristics of tight epithelial cells, in particular Na(+) absorption stimulated by aldosterone, has been extensively used for pharmacological studies related to the regulation of ion transport. These cells have permitted the identification of several aldosterone-induced proteins playing a key role in the regulation of Na(+) absorption mediated by the epithelial Na(+) channel ENaC. Recent studies have also provided evidence that these cell lines represent valuable cell systems for the study of host-pathogen interactions and the analysis of the role of renal tubule epithelial cells in the induction of inflammatory response caused by uropathogens that may lead to severe renal damage. PMID:17219250

Chassin, C; Bens, M; Vandewalle, A

2007-01-11

62

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

63

Characterization of a Novel SOD-1(G93A) Transgenic Mouse Line with Very Decelerated Disease Development  

PubMed Central

Amyotrophic Lateral Sclerosis (ALS) is a fatal motoneuron disease, characterized by progressive weakness, muscle wasting and death ensuing 3–5 years after diagnosis. The etiology of ALS is complex and therapeutic approaches rely mostly on transgenic animal models with SOD-1 mutations. Most frequently employed is a mouse line transgenic for SOD-1 (SOD-1 Tg) that contains a point mutation at amino acid position 93 (G->A), present in patients suffering from a familial form of amyotrophic lateral sclerosis. Here we report on a SOD-1 (G93A) Tg mouse line with abnormally delayed onset of disease and prolonged survival. This phenotype arose spontaneously in our colony of the classic SOD-1 (G93A) line. We found that the copy number of the SOD-1 transgene was drastically decreased. We established a new breeding colony, the SOD-1 (G93A)PS line (PS for prolonged survival) where the phenotype is stably inherited for 4 generations now. The mice develop symptoms at an age of approximately 12 months and die at 15 months of age. The delayed development of disease may more closely mimic human pathophysiology, and studying drug effects in this model may yield added confidence for potential efficacy of ALS drug candidates.

Henriques, Alexandre; Pitzer, Claudia; Schneider, Armin

2010-01-01

64

High Efficiency Production of germ-line Transgenic Japanese Medaka ( Oryzias latipes ) by Electroporation with Direct Current-shifted Radio Frequency Pulses  

Microsoft Academic Search

Although there have been several studies showing the production of transgenic fish through electroporation techniques, success rates have been low and few studies show germ-line integration and expression. When electroporation has been successful, the device used is no longer commercially available. The goal of this experiment was to find an alternative efficient method of generating transgenic Japanese medaka (Oryzias latipes)

Heather A. Hostetler; Stephanie L. Peck; William M. Muir

2003-01-01

65

Fast-tracking development of homozygous transgenic cereal lines using a simple and highly flexible real-time PCR assay  

PubMed Central

Background A crucial step in the evaluation of newly produced transgenic plants is the selection of homozygous plants. Here we describe an efficient and highly flexible real-time PCR-based method for the development of homozygous lines in plant models with complex (multiple) genomes and/or relatively long generation times (>3 months) using direct copy number determinations. Results An existing DNA extraction method was converted into a high-throughput plant leaf DNA extraction procedure yielding DNA suitable for real-time PCR analyses. Highly specific and efficient primer pairs were developed for a bread wheat reference gene (Epsilon Cyclase) and for standard sequence elements in the gene cassette routinely used for cereal transformations (an intron bridge and the Nopaline Synthase terminator). The real-time PCR assay reliably distinguished wheat plants with a single copy of the transgene from individuals with multiple copies or those lacking the transgene. To obtain homozygous lines carrying a unique insertion event as efficiently as possible, T0 plants (plants raised from transformed callus) with a single copy of the transgene were selected and their progeny screened for homozygous plants. Finally, the assay was adapted to work on rice. Conclusions The ability to quickly, easily and accurately quantify the construct copy numbers, as provided by the real-time PCR assay, greatly improved the efficiency and reliability of the selection of homozygous transgenic plants in our case study. We were able to select homozygous plants in early generations, avoiding time-consuming methods such as large scale analysis of segregation patterns of descendants and/or Southern blotting. Additionally, the ability to specifically develop homozygous lines carrying a unique insertion event could be important in avoiding gene silencing due to co-suppression, and if needed assist in the selection of lines suitable for future deregulation. The same primer pairs can be used to quantify many different wheat transgenic events because the construct-specific primer pairs are targeted to standard sequence elements of the cereal gene cassettes, making the method widely applicable in wheat GM research. Moreover, because all procedures described here are standardized, the method may easily be adapted to vectors lacking the target regions used here and/or to other plant models.

2013-01-01

66

Transgene copy number comparison in recombinant mammalian cell lines: critical reflection of quantitative real-time PCR evaluation.  

PubMed

Nucleic acid quantification is a relevant issue for the characterization of mammalian recombinant cell lines and also for the registration of producer clones. Quantitative real-time PCR is a powerful tool to investigate nucleic acid levels but numerous different quantification strategies exist, which sometimes lead to misinterpretation of obtained qPCR data. In contrast to absolute quantification using amplicon- or plasmid standard curves, relative quantification strategies relate the gene of interest to an endogenous reference gene. The relative quantification methods also consider the amplification efficiency for the calculation of the gene copy number and thus more accurate results compared to absolute quantification methods are generated. In this study two recombinant Chinese hamster ovary cell lines were analysed for their transgene copy number using different relative quantification strategies. The individual calculation methods resulted in differences of relative gene copy numbers because efficiency calculations have strong impact on gene copy numbers. However, in context of comparing transgene copy numbers of two individual clones the influence of the calculation method is marginal. Therefore especially for the comparison of two cell lines with the identical transgene any of the relative qPCR methods was proven as powerful tool. PMID:23807595

Sommeregger, Wolfgang; Prewein, Bernhard; Reinhart, David; Mader, Alexander; Kunert, Renate

2013-06-27

67

Direct derivation of conditionally immortal cell lines from an H-2Kb-tsA58 transgenic mouse.  

PubMed Central

Studies on cell lines have greatly improved our understanding of many important biological questions. Generation of cell lines is facilitated by the introduction of immortalizing oncogenes into cell types of interest. One gene known to immortalize many different cell types in vitro encodes the simian virus 40 (SV40) large tumor (T) antigen (TAg). To circumvent the need for gene insertion in vitro to generate cell lines, we created transgenic mice harboring the SV40 TAg gene. Since previous studies have shown that TAg expression in transgenic mice is associated with tumorigenesis and aberrant development, we utilized a thermolabile TAg [from a SV40 strain, tsA58, temperature sensitive (ts) for transformation] to reduce the levels of functional TAg present in vivo. To direct expression to a broad range of tissues, we used the mouse major histocompatibility complex H-2Kb promoter, which is both widely active and can be further induced by interferons. tsA58 TAg mRNA was expressed in tissues of all animals harboring the hybrid construct. Development of all tissues was macroscopically normal except for thymus, which consistently showed hyperplasia. Fibroblast and cytokeratin+ thymic epithelial cultures from these mice were readily established without undergoing crisis and were conditionally immortal in their growth; the degree of conditionality was correlated with the levels of tsA58 TAg detected. One strain of H-2Kb-tsA58 mice has been bred through several generations to homozygosity and transmits a functional copy of the transgene. Images

Jat, P S; Noble, M D; Ataliotis, P; Tanaka, Y; Yannoutsos, N; Larsen, L; Kioussis, D

1991-01-01

68

Direct derivation of conditionally immortal cell lines from an H-2Kb-tsA58 transgenic mouse.  

PubMed

Studies on cell lines have greatly improved our understanding of many important biological questions. Generation of cell lines is facilitated by the introduction of immortalizing oncogenes into cell types of interest. One gene known to immortalize many different cell types in vitro encodes the simian virus 40 (SV40) large tumor (T) antigen (TAg). To circumvent the need for gene insertion in vitro to generate cell lines, we created transgenic mice harboring the SV40 TAg gene. Since previous studies have shown that TAg expression in transgenic mice is associated with tumorigenesis and aberrant development, we utilized a thermolabile TAg [from a SV40 strain, tsA58, temperature sensitive (ts) for transformation] to reduce the levels of functional TAg present in vivo. To direct expression to a broad range of tissues, we used the mouse major histocompatibility complex H-2Kb promoter, which is both widely active and can be further induced by interferons. tsA58 TAg mRNA was expressed in tissues of all animals harboring the hybrid construct. Development of all tissues was macroscopically normal except for thymus, which consistently showed hyperplasia. Fibroblast and cytokeratin+ thymic epithelial cultures from these mice were readily established without undergoing crisis and were conditionally immortal in their growth; the degree of conditionality was correlated with the levels of tsA58 TAg detected. One strain of H-2Kb-tsA58 mice has been bred through several generations to homozygosity and transmits a functional copy of the transgene. PMID:1711218

Jat, P S; Noble, M D; Ataliotis, P; Tanaka, Y; Yannoutsos, N; Larsen, L; Kioussis, D

1991-06-15

69

Impact of six transgenic Bacillus thuringiensis rice lines on four nontarget thrips species attacking rice panicles in the paddy field.  

PubMed

As a key component of ecological risk assessments, nontarget effects of Bacillus thuringiensis (Bt) rice have been tested under laboratory and field conditions for various organisms. A 2-yr field experiment was conducted to observe the nontarget effects of six transgenic rice lines (expressing the Cry1Ab or fused protein of Cry1Ab and Cry1Ac) on four nontarget thrips species including Frankliniella intonsa (Trybom), F. tenuicornis (Uzel), Haplothrips aculeatus (F.), and H. tritici (Kurd), as compared with their rice parental control lines. Two sampling methods including the beat plate and plastic bag method were used to monitor the population densities of the four thrips species for 2 yr. The results showed that the seasonal average densities of four tested thrips species in Bt rice plots were significantly lower than or very similar to those in the non-Bt rice plots depending on rice genotypes, sampling methods, and years. Among all six tested Bt rice lines, transgenic B1 and KMD2 lines suppressed the population of these tested thrips species the most. Our results indicate that the tested Bt rice lines are unlikely to result in high population pressure of thrips species in comparison with non-Bt rice. In some cases, Bt rice lines could significantly suppress thrips populations in the rice ecosystem. In addition, compatibility of Bt rice, with rice host plant resistance to nontarget sucking pests is also discussed within an overall integrated pest management program for rice. PMID:23339799

Akhtar, Z R; Tian, J C; Chen, Y; Fang, Q; Hu, C; Peng, Y F; Ye, G Y

2013-02-01

70

Two Types of Tet-On Transgenic Lines for Doxycycline-Inducible Gene Expression in Zebrafish Rod Photoreceptors and a Gateway-Based Tet-On Toolkit  

PubMed Central

The ability to control transgene expression within specific tissues is an important tool for studying the molecular and cellular mechanisms of development, physiology, and disease. We developed a Tet-On system for spatial and temporal control of transgene expression in zebrafish rod photoreceptors. We generated two transgenic lines using the Xenopus rhodopsin promoter to drive the reverse tetracycline-controlled transcriptional transactivator (rtTA), one with self-reporting GFP activity and one with an epitope tagged rtTA. The self-reporting line includes a tetracycline response element (TRE)-driven GFP and, in the presence of doxycycline, expresses GFP in larval and adult rods. A time-course of doxycycline treatment demonstrates that maximal induction of GFP expression, as determined by the number of GFP-positive rods, is reached within approximately 24 hours of drug treatment. The epitope-tagged transgenic line eliminates the need for the self-reporting GFP activity by expressing a FLAG-tagged rtTA protein. Both lines demonstrate strong induction of TRE-driven transgenes from plasmids microinjected into one-cell embryos. These results show that spatial and temporal control of transgene expression can be achieved in rod photoreceptors. Additionally, system components are constructed in Gateway compatible vectors for the rapid cloning of doxycycline-inducible transgenes and use in other areas of zebrafish research.

Jensen, Abbie M.

2012-01-01

71

Visualization of Craniofacial Development in the sox10: kaede Transgenic Zebrafish Line Using Time-lapse Confocal Microscopy.  

PubMed

Vertebrate palatogenesis is a highly choreographed and complex developmental process, which involves migration of cranial neural crest (CNC) cells, convergence and extension of facial prominences, and maturation of the craniofacial skeleton. To study the contribution of the cranial neural crest to specific regions of the zebrafish palate a sox10: kaede transgenic zebrafish line was generated. Sox10 provides lineage restriction of the kaede reporter protein to the neural crest, thereby making the cell labeling a more precise process than traditional dye or reporter mRNA injection. Kaede is a photo-convertible protein that turns from green to red after photo activation and makes it possible to follow cells precisely. The sox10: kaede transgenic line was used to perform lineage analysis to delineate CNC cell populations that give rise to maxillary versus mandibular elements and illustrate homology of facial prominences to amniotes. This protocol describes the steps to generate a live time-lapse video of a sox10: kaede zebrafish embryo. Development of the ethmoid plate will serve as a practical example. This protocol can be applied to making a time-lapse confocal recording of any kaede or similar photoconvertible reporter protein in transgenic zebrafish. Furthermore, it can be used to capture not only normal, but also abnormal development of craniofacial structures in the zebrafish mutants. PMID:24121214

Gfrerer, Lisa; Dougherty, Max; Liao, Eric C

2013-09-30

72

Transgenic rice lines expressing maize C1 and R-S regulatory genes produce various flavonoids in the endosperm.  

PubMed

Flavonoids, compounds that possess diverse health-promoting benefits, are lacking in the endosperm of rice. Therefore, to develop transgenic lines that produce flavonoids, we transformed a white rice cultivar, Oryza sativa japonica cv. Hwa-Young, with maize C1 and R-S regulatory genes. Expression of these transgenes was restricted to the endosperm using the promoter of a rice prolamin gene. The pericarp of the C1/R-S homozygous lines became dark brown in accordance with their maternal genotype, whereas the endosperm turned chalky, similar to the opaque kernel phenotype. Analysis via high-performance liquid chromatography (HPLC) revealed that numerous kinds of flavonoids were produced in these transgenic kernels. To identify individual flavonoids, the number of HPLC peaks was reduced through moderate acid hydrolysis, followed by ethyl acetate partitioning. Amongst the major flavonoids, dihydroquercetin (taxifolin), dihydroisorhamnetin (3'-O-methyl taxifolin) and 3'-O-methyl quercetin were identified through liquid chromatography/mass spectrometry/mass spectrometry and nuclear magnetic resonance analyses. Fluorescence labelling with diphenylboric acid showed that the flavonoids were highly concentrated in the cells of four to five outer endosperm layers. More importantly, a high fluorescence signal was present in the cytosol of the inner endosperm layers. However, the overall signal in the inner layers was significantly lower because starch granules and protein bodies occupied most of the cytosolic space. Our estimate of the total flavonoid content in the transgenic kernels suggests that C1/R-S rice has the potential to be developed further as a novel variety that can produce various flavonoids in its endosperm. PMID:17147636

Shin, Young-Mi; Park, Hee-Jin; Yim, Sun-Duck; Baek, Nam-In; Lee, Choong-Hwan; An, Gynheung; Woo, Young-Min

2006-05-01

73

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

PubMed

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 attention was paid to nutritional properties of diets, caecal metabolism and serum indices. Genetic modification of potato had no negative effect on the chemical composition and nutritional properties of tubers, ecosystem of the caecum, activity of serum enzymes and non-specific defence mechanism of the rats. Obtained results indicate that transgenic potato with improved resistance to PVY(N): line R1F (truncated gene coding for PVY(N) polymerase in sense orientation), R2P (truncated gene coding for PVY(N) polymerase in antisense orientation), and NTR1.16 (non-translated regions of PVY(N) genome in sense orientation) are substantial and nutritional equivalence to the non-transgenic cultivar. Tubers of transgenic line NTR2.27 (non-translated regions of PVY(N) genome in antisense orientation) increased the bulk of caecal digesta and the production of SCFA as compared to tubers of the conventional cultivar and the other transgenic clones. Taking into account some deviations, it seems reasonable to undertake a long-term feeding study to confirm the nutritional properties of tubers of transgenic lines. PMID:16175247

Ju?kiewicz, Jerzy; Zdu?czyk, Zenon; Fornal, Józef

2005-01-01

74

Derivation and characterization of embryonic stem cells lines derived from transgenic Fischer 344 and Dark Agouti rats.  

PubMed

Rat embryonic stem cell (ESC) lines are not widely available, and there are only 2 lines available for distribution. Here, ESC lines were derived and characterized from Fischer 344 (F344) rats that express marker transgenes either ?-galactosidase or human placental alkaline phosphatase (AP), nontransgenic F344 rats, and from Dark Agouti (DA) rats. The ESC lines were maintained in an undifferentiated state as characterized by colony morphology, expression of Oct4, Nanog, Sox-2, Cdx2, and Stella, staining for AP, and stage-specific embryonic antigen-1. Pluripotency was demonstrated in vitro by differentiation to embryoid bodies, followed by embryonic monsters. The Cdx2 expression by ESCs was unexpected and was confirmed via reverse transcriptase-polymerase chain reaction, immunocytochemistry. Pluripotency of ESCs was demonstrated in vivo by production of teratoma after an injection into F344 nontransgenic rats, and by an injection of male DA ESCs into F344 or Sprague-Dawley rat blastocysts and the generation of chimeric rats and germline contribution. ESCs from both F344 and DA contributed to chimeric rats, and one DA ESC line was proved to be germline competent. ESC sublines were created by transfection with a plasmid expressing enhanced green fluorescent protein (eGFP) under the control of a beta actin promoter and cytomegalovirus enhancer (pCX-eGFP) or by transfection with a plasmid expressing GFP under the control of a 3.1 kb portion of the rat Oct4 promoter (pN1-Oct4-GFP). In pN1-Oct4-GFP sublines, GFP gene expression and fluorescence were shown to be correlated with endogenous Oct4 gene expression. Therefore, these new ESC lines may be useful for tissue engineering and transplantation studies or for optimizing culture conditions required for self-renewal and differentiation of rat ESCs. While they made chimeric rats, further work is needed to confirm whether the transgenic F344 rat ESCs described here are germline-competent ESCs. PMID:21995453

Hong, James; He, Hong; Weiss, Mark L

2011-11-22

75

Derivation and Characterization of Embryonic Stem Cells Lines Derived from Transgenic Fischer 344 and Dark Agouti Rats  

PubMed Central

Rat embryonic stem cell (ESC) lines are not widely available, and there are only 2 lines available for distribution. Here, ESC lines were derived and characterized from Fischer 344 (F344) rats that express marker transgenes either ?-galactosidase or human placental alkaline phosphatase (AP), nontransgenic F344 rats, and from Dark Agouti (DA) rats. The ESC lines were maintained in an undifferentiated state as characterized by colony morphology, expression of Oct4, Nanog, Sox-2, Cdx2, and Stella, staining for AP, and stage-specific embryonic antigen-1. Pluripotency was demonstrated in vitro by differentiation to embryoid bodies, followed by embryonic monsters. The Cdx2 expression by ESCs was unexpected and was confirmed via reverse transcriptase-polymerase chain reaction, immunocytochemistry. Pluripotency of ESCs was demonstrated in vivo by production of teratoma after an injection into F344 nontransgenic rats, and by an injection of male DA ESCs into F344 or Sprague-Dawley rat blastocysts and the generation of chimeric rats and germline contribution. ESCs from both F344 and DA contributed to chimeric rats, and one DA ESC line was proved to be germline competent. ESC sublines were created by transfection with a plasmid expressing enhanced green fluorescent protein (eGFP) under the control of a beta actin promoter and cytomegalovirus enhancer (pCX-eGFP) or by transfection with a plasmid expressing GFP under the control of a 3.1?kb portion of the rat Oct4 promoter (pN1-Oct4-GFP). In pN1-Oct4-GFP sublines, GFP gene expression and fluorescence were shown to be correlated with endogenous Oct4 gene expression. Therefore, these new ESC lines may be useful for tissue engineering and transplantation studies or for optimizing culture conditions required for self-renewal and differentiation of rat ESCs. While they made chimeric rats, further work is needed to confirm whether the transgenic F344 rat ESCs described here are germline-competent ESCs.

Hong, James; He, Hong

2012-01-01

76

Complex transgene locus structures implicate multiple mechanisms for plant transgene rearrangement  

Microsoft Academic Search

Summary To more fully characterize the internal structure of transgene loci and to gain further understanding of mechanisms of transgene locus formation, we sequenced more than 160 kb of complex transgene loci in two unrelated transgenic oat (Avena sativa L.) lines transformed using microprojectile bombardment. The transgene locus sequences from both lines exhibited extreme scrambling of non-contiguous transgene and genomic

Sergei K. Svitashevy; Wojciech P. Pawlowskiy; Irina Makarevitch; David W. Plank; David A. Somers

2002-01-01

77

Transgenic planarian lines obtained by electroporation using transposon-derived vectors and an eye-specific GFP marker  

PubMed Central

To generate transgenic planarians we used a set of versatile vectors for animal transgenesis based on the promiscuous transposons, mariner, Hermes and piggyBac, and a universal enhanced GFP (EGFP) marker system with three Pax6 dimeric binding sites, the 3xP3-EGFP developed by Berghammer et al. [Berghammer, A. J., Klinger, M. & Wimmer, E. A. (1999) Nature 402, 370–371]. This marker is expressed specifically in the eyes of various arthropod taxa. Upon microinjection into the parenchyma of adult planarians and subsequent electroporation, these vectors transpose efficiently into the planarian genome. One of the cell types transformed are the totipotent “neoblast” stem cells present in the adults, representing 30% of total cells. The neoblast represents a unique cell type with the capacity to proliferate and to differentiate into all somatic cell types as well as into germ cells. All three transposon vectors have high transformation efficiency, but only Hermes and piggyBac show stable integration. The mariner vector is frequently lost presumably because of the presence of active mariner-type transposons in the genome of the Girardia tigrina. Transformed animals are mosaics containing both transformed and untransformed neoblasts. These differentiate to form EGFP-positive and -negative photoreceptor cells. Such mosaicism is maintained through several cycles of regeneration induced by decapitation or asexual reproduction. Transformed neoblasts also contribute to the germ line, and can give rise to pure transgenic planarian lines in which EGFP is expressed in all photoreceptor cells after sexual reproduction. The presence of the transgenes was confirmed by PCR, plasmid rescue assay, inverse PCR, and Southern blotting. Our results with the 3xP3-EGFP marker confirm the presence of Pax6 activity in the differentiated photoreceptor cells of planarian eyes. Transgenesis will be an important tool to dissect developmental molecular mechanisms in planarian regeneration, development and stem cell biology, and may also be an entry point to analyze the biology of parasitic Platyhelminthes.

Gonzalez-Estevez, C.; Momose, T.; Gehring, W. J.; Salo, E.

2003-01-01

78

Enhanced sheath blight resistance in transgenic rice expressing an endochitinase gene from Trichoderma virens  

Microsoft Academic Search

The 42-kDa endochitinase (cht42) gene from the mycoparasitic fungus, Trichoderma virens, driven by CaMV 35S promoter, was introduced into rice by Agrobacterium-mediated transformation. Eight transgenic plants harboring single copies of complete T-DNA were identified by Southern blot\\u000a analysis. Homozygous transgenic plants were identified for five lines in the T1 generation by Southern blot analysis. Homozygous T2 plants constitutively accumulated high

Jasmine M. Shah; Vengoji Raghupathy; Karuppannan Veluthambi

2009-01-01

79

A transgenic Tbx6;CreERT2 line for inducible gene manipulation in the presomitic mesoderm  

PubMed Central

The rhythmic segmentation process of the presomitic mesoderm (PSM) orchestrates the formation of somites, the fundamental units for the vertebrate axial body plan. To aid the investigation of molecular components governing the conversion from PSM into somites, we generated a transgenic mouse line that expresses a tamoxifen (tmx) inducible CreERT2 under the control of a 2.5kb enhancer element of Tbx6, a gene essential for PSM formation and somite patterning. Combined with Cre reporters, this Tbx6;CreERT2 line displays robust tmx-inducible Cre activity in the PSM at various embryonic stages. This tool should be useful for studying gene function during somitogenesis by either conditional inactivation or mis-expression, and potentially coupled with cell marking.

Lopez, T. Peter; Fan, Chen-Ming

2012-01-01

80

Molecular Cytogenetic Analyses of HIG, a Novel Human Cell Line Carrying t(1;3)(p36.3;q25.3) Established from a Patient with Chronic Myelogenous Leukemia in Blastic Crisis  

Microsoft Academic Search

Chromosomal abnormalities involving 1p36, 3q21, and\\/or 3q26 have been reported in a subset of myeloid neoplasms having characteristic\\u000a dysmegakaryopoiesis, and the overexpression ofEVI1 on 3q26 or ofMEL1 on 1p36 has been implicated in their pathogenesis. We describe molecular cytogenetic analyses of a novel human cell line,\\u000a HIG, established from a unique case in which a novel translocation t(1;3)(p36;q26) appeared as

Noriko Hosoya; Seishi Ogawa; Tohru Motokura; Akira Hangaishi; Lili Wang; Ying Qiao; Yasuhito Nannya; Mieko Kogi; Hisamaru Hirai

2003-01-01

81

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.

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

2011-01-01

82

Development of transgenic lines of Eimeria tenella expressing M2e-enhanced yellow fluorescent protein (M2e-EYFP).  

PubMed

Eimeria parasites are obligate intracellular apicomplexan protists that can cause coccidiosis, resulting in substantial economic losses in the poultry industry annually. As the component of anticoccidial vaccines, seven Eimeria spp. of chickens are characterized with potent immunogenicity. Whether genetically modified Eimeria spp. maintains this property or not needs to be verified. In this study, two identical transgenic lines of Eimeria tenella were developed by virtue of single sporocyst isolation from a stably transfected population expressing fused protein of M2 ectodomain of avian influenza virus (M2e) and enhanced yellow fluorescent protein (EYFP). The chromosomal integration and expression of M2e-EYFP were confirmed by Southern blot, plasmid rescue and Western blot analysis. We found that the reproduction of transgenic parasites was higher than that of the parental strain. Chickens challenged with wild type E. tenella after immunization with 200 oocysts of transgenic parasites had similar performance compared to those in non-immunized and non-challenged group. In another trial, the performance of transgenic parasite-immunized birds was also comparable to that of the Decoquinate Premix-treated chickens. These results suggest that this transgenic line of E. tenella is capable of inducing potent protection against homologous challenge as a live anticoccidial vaccine. Taking together, our study indicates that transgenic eimerian parasites have the potential to be developed as a vaccine vehicle for animal use in the future. PMID:23298569

Liu, Xianyong; Zou, Jun; Yin, Guangwen; Su, Huali; Huang, Xiaoxi; Li, Jianan; Xie, Li; Cao, Yingqiong; Cui, Yujuan; Suo, Xun

2012-12-20

83

Fluorescence-Tagged Transgenic Lines Reveal Genetic Defects in Pollen Growth--Application to the Eif3 Complex  

PubMed Central

Background Mutations in several subunits of eukaryotic translation initiation factor 3 (eIF3) cause male transmission defects in Arabidopsis thaliana. To identify the stage of pollen development at which eIF3 becomes essential it is desirable to examine viable pollen and distinguish mutant from wild type. To accomplish this we have developed a broadly applicable method to track mutant alleles that are not already tagged by a visible marker gene through the male lineage of Arabidopsis. Methodology/Principal Findings Fluorescence tagged lines (FTLs) harbor a transgenic fluorescent protein gene (XFP) expressed by the pollen-specific LAT52 promoter at a defined chromosomal position. In the existing collection of FTLs there are enough XFP marker genes to track nearly every nuclear gene by virtue of its genetic linkage to a transgenic marker gene. Using FTLs in a quartet mutant, which yields mature pollen tetrads, we determined that the pollen transmission defect of the eif3h-1 allele is due to a combination of reduced pollen germination and reduced pollen tube elongation. We also detected reduced pollen germination for eif3e. However, neither eif3h nor eif3e, unlike other known gametophytic mutations, measurably disrupted the early stages of pollen maturation. Conclusion/Significance eIF3h and eIF3e both become essential during pollen germination, a stage of vigorous translation of newly transcribed mRNAs. These data delimit the end of the developmental window during which paternal rescue is still possible. Moreover, the FTL collection of mapped fluorescent protein transgenes represents an attractive resource for elucidating the pollen development phenotypes of any fine-mapped mutation in Arabidopsis.

Roy, Bijoyita; Copenhaver, Gregory P.; von Arnim, Albrecht G.

2011-01-01

84

Effects of two Bt rice lines T2A-1 and T1C-19 on the ecological fitness and detoxification enzymes of Nilaparvata lugens (Hemiptera: Delphacidae) from different populations.  

PubMed

The brown planthopper, Nilaparvata lugens Stĺl (Hemiptera: Delphacidae), exhibits geographic and temporal variations in its virulence and damage characteristics on cultivated rice varieties, so the potential ecological risk of the nontarget effectiveness of Bt rice on different brown planthopper populations should be addressed. The nontarget effects of two Bt rice lines T2A-1 (Cry2A rice) and T1C-19 (Cry1C rice) on six brown planthopper populations with geographical, virulent, and resistant variations were evaluated. Populations differed significantly in relation to brown planthopper nymphal survival, nymphal duration, and female adult weight. T2A-1 and T1C-19 did not affect the ecological fitness parameters of brown planthopper compared with the parental non-Bt rice MH63. Both esterase and glutathione-S-transferase activities differed between brown planthopper populations. Esterase activity of some brown planthopper populations was significantly affected by the rice lines. It is important to take account of these findings in management ofnontarget brown planthopper in Cry2A or Cry1C rice in the future. PMID:24020307

Yang, Yajun; He, Jingjing; Dong, Biqin; Xu, Hongxing; Fu, Qiang; Zheng, Xusong; Lin, Yongjun; Lu, Zhongxian

2013-08-01

85

Amplification of the Ect2 proto-oncogene and over-expression of Ect2 mRNA and protein in nickel compound and methylcholanthrene-transformed 10T1/2 mouse fibroblast cell lines.  

PubMed

Occupational exposure of humans to mixtures of insoluble and soluble nickel (Ni) compounds correlates with increased incidences of lung, sinus, and pharyngeal tumors. Specific insoluble Ni compounds are carcinogenic to animals by inhalation and induce morphological and neoplastic transformation of cultured rodent cells. Our objectives were to (1) understand mechanisms of nickel ion-induced cell transformation, hence carcinogenesis and (2) develop biomarkers of nickel ion exposure and nickel ion-induced cell transformation. We isolated mRNAs from green nickel oxide (NiO), crystalline nickel monosulfide (NiS), and 3-methylcholanthrene (MCA) transformed C3H/10T1/2 Cl 8 cell lines, and determined by mRNA differential display that nine mRNA fragments were differentially expressed between Ni transformed and non-transformed 10T1/2 cell lines. Fragment R2-5 was expressed at higher steady-state levels in the transformed cell lines. R2-5 had 100% sequence identity to part of the coding region of Ect2, a mouse proto-oncogene encoding a GDP-GTP exchange factor. The 3.9-kb Ect2 transcript was expressed at 1.6- to 3.6-fold higher steady-state levels in four Ni transformed, and in two MCA-transformed, cell lines. Ect2 protein was expressed at 3.0- to 4.5-fold higher steady-state levels in Ni-transformed and in MCA-transformed cell lines. The Ect2 gene was amplified by 3.5- to 10-fold in Ni transformed, and by 2.5- to 3-fold in MCA transformed cell lines. Binding of nickel ions to enzymes of DNA synthesis likely caused amplification of the Ect2 gene. Ect2 gene amplification and over-expression of Ect2 mRNA and protein can cause microtubule disassembly and cytokinesis, contributing to induction and maintenance of morphological, anchorage-independent, and neoplastic transformation of these cell lines. Over-expression of Ect2 protein is a useful biomarker to detect exposure to nickel compounds and nickel ion-induced morphological and neoplastic cell transformation. PMID:15967202

Clemens, Farrah; Verma, Rini; Ramnath, Jamuna; Landolph, Joseph R

2005-08-01

86

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

87

The transgene pyramiding tobacco with betaine synthesis and heterologous expression of AtNHX1 is more tolerant to salt stress than either of the tobacco lines with betaine synthesis or AtNHX1.  

PubMed

Previous studies have shown that the overexpression of betA (encoding choline dehydrogenase from Escherichia coli) or AtNHX1 (a vacuolar Na(+)/H(+) antiport from Arabidopsis thaliana) gene can improve the salt tolerance of transgenic plants. However, little is known about the effects of the transgene pyramiding of betA and AtNHX1. Here, betA + AtNHX1 transgene pyramiding tobacco was produced by sexual crossing, and the salt tolerance was evaluated at the cellular and plant levels. In NaCl stress, the Na(+) concentration in vacuoles and vacuolar membrane potential of transgene pyramiding cells were similar to those of AtNHX1-transgenics, and much higher than those of betA-transgenics when detected using fluorescent dye staining; transgene pyramiding cells showed a higher protoplast viability and comparable mitochondrial activity as compared with single transgenics; and transgene pyramiding plants showed comparable Na(+) content in leaves as compared with AtNHX1-transgenics and remarkably higher than betA-transgenics; and transgene pyramiding lines exhibited higher percentage of seed germination, better seedling growth and higher fresh weight than lines that had betA or AtNHX1 alone. Based on the integrative analysis of salt tolerance, the consistency between the cellular level and the whole plant level was confirmed and the transgene pyramiding plants exhibited improved salt tolerance, but compared with the plants with betA or AtNHX1 alone, the differences were relatively small. Other mechanisms involved in salt tolerance should be considered to further enhance transgene pyramiding plants salt tolerance. PMID:19236662

Duan, XiaoGuang; Song, YingJie; Yang, AiFang; Zhang, JuRen

2009-03-01

88

Analyses of single-copy Arabidopsis T-DNA-transformed lines show that the presence of vector backbone sequences, short inverted repeats and DNA methylation is not sufficient or necessary for the induction of transgene silencing  

Microsoft Academic Search

In genetically transformed plants, transgene silen- cing has been correlated with multiple and complex insertions of foreign DNA, e.g. T-DNA and vector backbone sequences. Occasionally, single-copy transgenes also suffer transgene silencing. We have compared integration patterns and T-DNA\\/plant DNA junctions in a collection of 37 single-copy T-DNA-transformed Arabidopsis lines, of which 13 displayed silencing. Vector sequences were found integrated in

Trine J. Meza; Biljana Stangeland; Inderjit S. Mercy; Magne Skarn; Dag A. Nymoen; Anita Berg; Melinka A. Butenko; Anne-Mari Hakelien; Camilla Haslekas; Leonardo A. Meza-Zepeda; Reidunn B. Aalen

2002-01-01

89

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

2009-11-27

90

Serotonin transporter transgenic (SERTcre) mouse line reveals developmental targets of serotonin specific reuptake inhibitors (SSRIs).  

PubMed

The serotonin transporter gene (SLC6A4; synonyms, SERT, 5-HTT) is expressed much more broadly during development than in adulthood. To obtain a full picture of all sites of SERT expression during development we used a new mouse model where Cre recombinase was inserted into the gene encoding the serotonin transporter. Two reporter mouse lines, ROSA26R and the Tau(mGFP), allowed to map all the cells that express SERT at any point during development. Combined LacZ histochemistry and GFP immunolabelling showed neuronal cell bodies and axon fiber tracts. Earliest recombination in embryos was visible in the periphery in the heart and liver by E10.5 followed by recombination in the brain in raphe serotonergic neurons by E12.5. Further, recombination in non-serotonin neurons was visible in the choroid plexus, roof plate, and neural crest derivatives; by E15.5, recombination was found in the dorsal thalamus, cingulate cortex, CA3 field of the hippocampus, retinal ganglion cells, superior olivary nucleus and cochlear nucleus. Postnatally, SERT mediated recombination was visible in the medial prefrontal cortex and layer VI neurons in the isocortex. Recombined cells were co-labelled with Neu-N, but not with GAD67, and were characterized by long range projections (corpus callosum, fornix, thalamocortical). This fate map of serotonin transporter expressing cells emphasizes the broad expression of SERT in non-serotonin neurons during development and clarifies the localization of SERT expression in the hippocampus and limbic cortex. The identification of targets of SSRIs and serotonin releasers during embryonic and early postnatal life helps understanding the very diverse physiological consequences of administration of these drugs during development. PMID:18789954

Narboux-Nęme, Nicolas; Pavone, Luigi Michele; Avallone, Luigi; Zhuang, Xiaoxi; Gaspar, Patricia

2008-08-26

91

An Efficient Transformation Method to Regenerate a High Number of Transgenic Plants Using a New Embryogenic Line of Medicago truncatula cv. Jemalong  

Microsoft Academic Search

A simple and efficient regeneration–transformation method was established to obtain transgenic plants of the model legume Medicago truncatula cv. Jemalong. This method takes advantage of a new highly embryogenic line (M9-10a) isolated in our laboratory. Leaflets of in vitro grown M9-10a plants were co-cultured with Agrobacterium tumefaciens EHA105. Plasmid constructs containing the oat arginine decarboxylase gene, Adc and the GUS

Susana de Sousa Araújo; Ana Sofia Roldăo Lopes Amaral Duque; Dulce Maria Metelo Fernandes dos Santos; Manuel Pedro Salema Fevereiro

2004-01-01

92

Transgenic mouse line overexpressing the cancer-specific tNOX protein has an enhanced growth and acquired drug-response phenotype  

Microsoft Academic Search

tNOX, a novel cell surface protein related to unregulated growth and drug response of cancer cells, has been proposed as the cellular target for the anticancer action of various quinone site inhibitors with anticancer activity including the polyphenol (?)-epigallocatechin-3-gallate (EGCg). A transgenic mouse line overexpressing tNOX was generated to determine its overall growth phenotype and susceptibility to EGCg. Cultured noncancer

Kader Yagiz; D. James Morré; Dorothy M. Morré

2006-01-01

93

Inducible responses to DNA damage in the mouse embryo fibroblasts cell line C3H/10T1/2 and its transformed counterpart C3H/MCA  

SciTech Connect

Early passage mouse embryo fibroblasts cells (C3H/10T1/2) were treated with ultraviolet (UV) radiation of 12-O-tetradecanoylphorbol-13-acetate (TPA) in order to determine whether such treatment induced DNA repair processes, measured as increased survival and mutagenesis of Herpes simplex (HSV-1). No enhanced host cell reactivation of UV-irradiated virus was observed following treatment of cells with UV-irradiation or TPA. Replication of undamaged virus in untreated C3H cells resulted in an increase over the background mutation frequency. When the cells were UV-irradiated and infected with unirradiated virus, a decrease in mutagenesis was observed. Decreased untargeted mutagenesis was shown to be dose- and time-dependent, reaching a minimum at a fluence of 5-7 Jm/sup /minus/2/ for 24 hours between irradiation and infection of cells. There was no change in mutagenesis of UV-irradiated virus grown in UV-irradiated cells compared to untreated cells. The repair capacity of methylcholanthrene-transformed C3H cells (MCA cells) was compared with untransformed C3H cells. The cell lines demonstrated similar cell survival curves following UV-irradiation but differed markedly in their ability to repair damaged HSV-1.

Miller, L.S.

1987-01-01

94

Production of Transgenic Quails with High Frequency of Germ-Line Transmission Using VSV-G Pseudotyped Retroviral Vector  

Microsoft Academic Search

We report here the production of transgenic quails using a replication-defective pantropic retroviral vector based on Moloney murine leukemia virus (MoMLV) pseudotyped with vesicular stomatitis virus G protein (VSV-G). The retroviral vector was injected into laid quail embryos at the blastodermal stage, and the embryos were incubated to hatch to produce G0 transgenic quails. Among 134 embryos subjected to viral

Shinji Mizuarai; Ken-ichiro Ono; Kazuhisa Yamaguchi; Ken-ichi Nishijima; Masamichi Kamihira; Shinji Iijima

2001-01-01

95

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

PubMed

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, Glycine max (L.) Merr. Additional sources of soybean insect resistance would be desirable to manage the development of tolerance/resistance to crystal proteins by defoliating insects and to sustain the deployment of Bt crops. The objective of this study was to evaluate the effects and interactions of three insect resistance quantitative trait loci (QTLs; QTL-M, QTL-H, and QTL-G) originating from Japanese soybean PI 229358 and a cry1Ac gene in a "Benning" genetic background. A set of 16 BC(6)F(2)-derived near isogenic lines (NILs) was developed using marker-assisted backcrosses and evaluated for resistance to soybean looper [SBL, Pseudoplusia includens (Walker)] and corn earworm [CEW, Helicoverpa zea (Boddie)] in field cage, greenhouse, and detached leaf assays. Both Bt and QTL-M had significantly reduced defoliation by both SBL and CEW and reduced larval weight of CEW. The antibiosis QTL-G had a significant effect on reducing CEW larval weight and also a significant effect on reducing defoliation by SBL and CEW in some assays. The antixenosis QTL-H had no main effect, but it appeared to function through interaction with QTL-M and QTL-G. Adding QTL-H and QTL-G further enhanced the resistance of the Bt and QTL-M combination to CEW in the field cage assay. These results should help guide the development of strategies for effective management of insect pests and for sustainable deployment of Bt genes. PMID:18064435

Zhu, S; Walker, D R; Boerma, H R; All, J N; Parrott, W A

2007-12-07

96

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.

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

2009-01-01

97

Agronomic performance and transcriptional analysis of carotenoid biosynthesis in fruits of transgenic HighCaro and control tomato lines under field conditions.  

PubMed

Genetic manipulation of carotenoid biosynthesis in higher plants has been the objective of a number of biotechnology programs, e.g. the Golden Rice Program. However, tomato (Solanum lycopersicum L.), which naturally accumulates lycopene in fruits, has attracted the attention of many groups who have manipulated it to increase or diversify carotenoid accumulation. One of the most significant achievements was "HighCaro (HC)," a transgenic tomato plant constitutively expressing the tomato lycopene beta-cyclase (tLcy-b), that produces orange fruits due to the complete conversion of lycopene to beta-carotene. In this article we report the results of a field trial conducted in Metaponto (Italy) on HC and on two control genotypes to evaluate the stability of the transgenic trait and their yield performances. Transcriptional regulation of eight genes involved in carotenogenesis was assayed by quantitative real-time PCR (qRT-PCR) analysis on fruits collected at four distinct development stages. Statistical analysis results demonstrated that in field conditions the transgene maintained its ability to induce the conversion of lycopene to beta-carotene. Moreover, agronomic performances and fruit quality in the transgenic line were not impaired by this metabolic disturbance. Results of qRT-PCR analysis suggested that transcription of PSY-1, PDS and ZDS genes were developmentally regulated in both genotypes. Unexpectedly, Lcy-b expression in transgenic fruits was also developmentally regulated, despite the fact that the gene was driven by a constitutive promoter. Our data provide evidence that in photosynthetic cells a strict and aspecific mechanism controls the level of transcripts until the onset of chromoplasts differentiation, at which point a gene-specific control on transcription takes place. PMID:17096211

Giorio, Giovanni; Stigliani, Adriana Lucia; D'Ambrosio, Caterina

2006-11-10

98

GFAP transgenic zebrafish  

Microsoft Academic Search

We have generated transgenic zebrafish that express green fluorescent protein (GFP) in glial cells driven by the zebrafish glial fibrillary acidic protein (GFAP) regulatory elements. Transgenic lines Tg(gfap:GFP) were generated from three founders; the results presented here are from the mi2001 line. GFP expression was first visible in the living embryo at the tail bud-stage, then in the developing brain

Rebecca L. Bernardos; Pamela A. Raymond

2006-01-01

99

An evolutionarily conserved mitochondrial orf108 is associated with cytoplasmic male sterility in different alloplasmic lines of Brassica juncea and induces male sterility in transgenic Arabidopsis thaliana.  

PubMed

Nuclear-mitochondrial gene interactions governing cytoplasmic male sterility (CMS) in angiosperms have been found to be unique to each system. Fertility restoration of three diverse alloplasmic CMS lines of Brassica juncea by a line carrying the fertility-restorer gene introgressed from Moricandia arvensis prompted this investigation to examine the molecular basis of CMS in these lines. Since previous studies had found altered atpA transcription associated with CMS in these lines, the atpA genes and transcripts of CMS, fertility-restored, and euplasmic lines were cloned and compared. atpA coding and downstream sequences were conserved among CMS and euplasmic lines but major differences were found in the 5' flanking sequences of atpA. A unique open reading frame (ORF), orf108, co-transcribed with atpA, was found in male sterile flowers of CMS lines carrying mitochondrial genomes of Diplotaxis berthautii, D. catholica, or D. erucoides. In presence of the restorer gene, the bicistronic orf108-atpA transcript was cleaved within orf108 to yield a monocistronic atpA transcript. Transgenic expression of orf108 with anther-specific Atprx18 promoter in Arabidopsis thaliana gave 50% pollen sterility, indicating that Orf108 is lethal at the gametophytic stage. Further, lack of transmission of orf108 to the progeny showed for the first time that mitochondrial ORFs could also cause female sterility. orf108 was found to be widely distributed among wild relatives of Brassica, indicating its ancient origin. This is the first report that shows that CMS lines of different origin and morphology could share common molecular basis. The gametic lethality of Orf108 offers a novel opportunity for transgene containment. PMID:22371076

Kumar, Pankaj; Vasupalli, Naresh; Srinivasan, R; Bhat, Shripad R

2012-02-27

100

Development and characterization of a progressive series of mammary adenocarcinoma cell lines derived from the C3(1)/SV40 Large T-antigen transgenic mouse model.  

PubMed

We have developed four new mammary adenocarcinoma cell lines from the C3(1)/SV40 Large T-antigen (Tag) transgenic mouse model: M28N2 and M27H4 (weakly tumorigenic), M6 (carcinoma), and M6C (metastatic). The C3(1) promoter directs Tag expression to the mammary epithelium and 100% of female C3(1)/Tag transgenic mice develop mammary adenocarcinoma in a predictable and progressive manner. The cell lines we developed from this model are demonstrated to be of epithelial origin and display growth rates, both in vitro and following subcutaneous inoculation into nude mice, that are consistent with their representative stage of tumor progression. The more tumorigenic cell lines, M6 and M6C, both express the sodium/iodide symporter, a mammary carcinoma cell marker with potential therapeutic and diagnostic applications. All of the cell lines express estrogen receptor (ER) alpha and ER beta mRNA, and Western blot analysis demonstrates that the ER alpha protein is down-regulated in the M6 and M6C cell lines. M28N2 cells also express progesterone receptor (PgR), which is very unusual in a mouse mammary carcinoma cell line. In addition, all of the cell lines display growth inhibition when plated in media supplemented with charcoal-stripped fetal calf serum (CS FBS). When CS FBS is supplemented with beta estradiol or the progestin MPA, no significant difference in growth rates is observed relative to growth in CS FBS. The development and characterization of a progressive series of new mammary carcinoma cell lines will aid in the study of mammary carcinoma progression both in vitro and in vivo. PMID:12602905

Holzer, Ryan G; MacDougall, Christina; Cortright, Gerry; Atwood, Kristi; Green, Jeffrey E; Jorcyk, Cheryl L

2003-01-01

101

Transgene Expression of Green Fluorescent Protein and Germ Line Transmission in Cloned Pigs Derived from In Vitro Transfected Adult Fibroblasts  

Microsoft Academic Search

The pig represents the xenogeneic donor of choice for future organ transplantation in humans for anatomical and physiological reasons. However, to bypass several immunological barriers, strong and stable human genes expression must occur in the pig's organs. In this study we created transgenic pigs using in vitro transfection of cultured cells combined with somatic cell nuclear transfer (SCNT) to evaluate

Dario Brunetti; Andrea Perota; Irina Lagutina; Silvia Colleoni; Roberto Duchi; Fiorella Calabrese; Michela Seveso; Emanuele Cozzi; Giovanna Lazzari; Franco Lucchini; Cesare Galli

2008-01-01

102

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

2012-11-02

103

Disturbed CD4+ T Cell Homeostasis and In Vitro HIV-1 Susceptibility in Transgenic Mice Expressing T Cell Line-tropic HIV-1 Receptors  

PubMed Central

T cell line–tropic (T-tropic) HIV type 1 strains enter cells by interacting with the cell-surface molecules CD4 and CXCR4. We have generated transgenic mice predominantly expressing human CD4 and CXCR4 on their CD4-positive T lymphocytes (CD4+ T cells). Their primary thymocytes are susceptible to T-tropic but not to macrophage-tropic HIV-1 infection in vitro, albeit with a viral antigen production less efficient than human peripheral blood mononuclear cells. Interestingly, even without HIV infection, transgenic mice display a CD4+ T cell depletion profile of peripheral blood reminiscent of that seen in AIDS patients. We demonstrate that CD4+ T cell trafficking in transgenic mice is biased toward bone marrow essentially due to CXCR4 overexpression, resulting in the severe loss of CD4+ T cells from circulating blood. Our data suggest that CXCR4 plays an important role in lymphocyte trafficking through tissues, especially between peripheral blood and bone marrow, participating in the regulation of lymphocyte homeostasis in these compartments. Based on these findings, we propose a hypothetical model in which the dual function of CXCR4 in HIV-1 infection and in lymphocyte trafficking may cooperatively induce progressive HIV-1 infection and CD4+ T cell decline in patients.

Sawada, Shinichiro; Gowrishankar, Kavitha; Kitamura, Rui; Suzuki, Misao; Suzuki, Gen; Tahara, Satoko; Koito, Atsushi

1998-01-01

104

Germ-line transmission and developmental regulation of a 150-kb yeast artificial chromosome containing the human [beta]-globin locus in transgenic mice  

SciTech Connect

Sequential expression of the genes of the human [beta]-globin locus requires the formation of an erythroid-specific chromatin domain spanning > 200 kb. Regulation of this gene family involves both local interactions with proximal cis-acting sequences and long-range interactions with control elements upstream of the locus. To make it possible to analyze the interactions of cis-acting sequences of the human [beta]-globin locus in their normal spatial and sequence context, the authors characterized two yeast artificial chromosomes (YACs) 150 and 230 kb in size, containing the entire [beta]-globin locus. They have now successfully integrated the 150 kb YAC into the germ line of transgenic mice as a single unrearranged fragment that includes the locus control region, structural genes, and 30 kb of 3[prime] flanking sequences present in the native locus. Expression of the transgenic human [beta]-globin locus is tissue- and developmental stage-specific and closely follows the pattern of expression of the endogenous mouse [beta]-globin locus. By using homology-directed recombination in yeast and methods for the purification and transfer of YACs into transgenic mice, it will now be feasible to study the physiological role of cis-acting sequences in specifying an erythroid-specific chromatin domain and directing expression of [beta]-globin genes during ontogeny.

Gaensler, K.M.L.; Kitamura, M.; Kan, Yuet Wai (Univ. of California, San Francisco, CA (United States))

1993-11-15

105

Effects of expression of human or bovine growth hormone genes on sperm production and male reproductive performance in four lines of transgenic mice  

Microsoft Academic Search

Summary. Reproductive performance was studied in transgenic males from lines expressing and transmitting four hybrid genes: mouse metallothionein-I\\/human growth hormone (GH) (MT\\/hGH), MT\\/hGH placental variant (MT\\/hGH\\\\m=.\\\\V),MT\\/bovine GH (MT\\/bGH) and phosphoenolpyruvate carboxykinase\\/bGH (PEPCK\\/bGH). Each male was exposed to three normal females for 1 week and to three different normal females for another week. Females were examined for vaginal plugs and necropsied

A. Bartke; E. M. Naar; L. Johnson; M. R. May; M. Cecim; J. S. Yun; T. E. Wagner

1992-01-01

106

Early detection and visualization of human adenovirus serotype 5-viral vectors carrying foot-and-mouth disease virus or luciferase transgenes in cell lines and bovine tissues.  

PubMed

Recombinant replication-defective human adenovirus type 5 (Ad5) vaccines containing capsid-coding regions from foot-and-mouth disease virus (FMDV) have been demonstrated to induce effective immune responses and provide homologous protective immunity against FMDV in cattle. However, basic mechanisms of Ad5-FMDV vaccine function including virus tropism, transgene expression, and antigen presentation, remain incompletely understood. The current study characterized the dynamics of Ad5 viral vector (Ad5-FMDV-A24 and Ad5-luciferase) infection in cell lines and early post-inoculation vector-host interactions in cattle. Adenovirus dissemination was described utilizing novel rPCR, rRT-PCR, luminometry, and immunomicroscopy techniques. In vitro infection of human and bovine cells with both Ad5 vectors resulted in dose-dependent detection of vector DNA, mature mRNA transcripts, and transgene-encoded proteins. Subsequent to intramuscular inoculation of cattle, Ad5 and transgene products were detected at the injection sites of all animals at all time-points examined (6, 24, and 48 hpi). Microscopically, injection sites were characterized by marked infiltrates of interstitium consisting of predominantly large mononuclear cells. Immunomicroscopy indicated these cells infrequently contained adenovirus and/or transgenic proteins and were phenotypically consistent with antigen-presenting cells (macrophages and dendritic cells). Vector DNA and mature mRNA transcripts were first detected at the draining and local lymph nodes as early as 6 hpi and systemically at 24 hpi. These results provide novel insights for understanding Ad5-mediated immunity against FMDV using novel techniques that will contribute to ongoing efforts for the improvement of future Ad-FMDV vaccine platforms. PMID:22227230

Montiel, Nestor; Smoliga, George; Arzt, Jonathan

2012-01-06

107

Enhancement of Recombinant Adeno-Associated Virus Type 2-Mediated Transgene Expression in a Lung Epithelial Cell Line by Inhibition of the Epidermal Growth Factor Receptor  

PubMed Central

Recombinant adeno-associated viruses (rAAVs) have attracted considerable interest as gene delivery systems because they show long-term expression in vivo and transduce numerous cell types. Limitations to successful gene transduction from rAAVs have prompted investigations of a variety of treatments to enhance transgene expression from rAAV vectors. Tyrphostin-1, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, dramatically enhances rAAV transgene expression. Elegant studies have demonstrated that a single-strand D-sequence-binding protein (ssDBP) is phosphorylated by EGFR and binds to the D sequence element in the AAV terminal repeat (TR). Binding of the Tyr-phosphorylated ssDBP prevents conversion of single-stranded vector DNA to a double-strand conformation. We observed dramatic increases in transgene expression in lung epithelial cells (IB3) with tyrphostin treatment. Gel shift analysis of ssDBP revealed that its DNA binding characteristics were unchanged after tyrphostin treatment or adenovirus infection. Tyrphostin stimulated rAAV transgene expression to a greater extent than adenovirus coinfection. Southern hybridizations revealed that the vector DNA remained in the single-strand conformation in tyrphostin-treated cells but double-stranded replicative form monomer DNA was most abundant in adenovirus-infected cells. Northern analyses revealed that tyrphostin treatment enhanced mRNA accumulation more than in adenovirus-infected cultures even though replicative form DNA was undetectable. Analysis of the JNK, ERK, and p38K mitogen-activated protein kinase pathways revealed that tyrphostin treatment stimulated the activity of JNK and p38K. Our data suggest that tyrphostin-induced alteration of stress response pathways results in dramatic enhancement of transcription on linear vector DNA templates in the IB3 cell line. These results expand the downstream targets of the EGFR in regulating rAAV transduction.

Smith, Andrew D.; Collaco, Roy F.; Trempe, James P.

2003-01-01

108

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

2013-03-26

109

Multiple strategies for gene transfer, expression, knockdown, and chromatin influence in mammalian cell lines and transgenic animals  

Microsoft Academic Search

Manipulation of the eukaryotic genome has contributed to the progress in our knowledge of multicellular organisms but has\\u000a also ameliorated our experimental strategies. Biological questions can now be addressed with more efficiency and reproducibility.\\u000a There are new and varied strategies for gene transfer and sequence manipulation with improved methodologies that facilitate\\u000a the acquisition of results. Cellular systems and transgenic animals

Félix Recillas-Targa

2006-01-01

110

Insect-resistant transgenic Pinus radiata  

Microsoft Academic Search

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

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

2005-01-01

111

A novel transgenic line using the Cre-lox system to allow permanent lineage-labeling of the zebrafish neural crest.  

PubMed

Accurate lineage tracing is crucial to understanding of developmental and stem cell biology, but is particularly challenging for transient and highly dispersive cell-types like the neural crest (NC). The authors report in this article a new zebrafish transgenic line Tg(-4725sox10:Cre)(ba74). This line expresses Cre under the control of a well-characterized portion of the sox10 promoter and, by crossing to a floxed-reporter line, the authors show in this article that expression in this line is consistent with those described for GFP reporter lines using the same promoter. Reporter expression is readily detected in patterns consistent with the early expression domains. Thus, the authors see all major groups (pigment, neural, and skeletal) of NC-derived cell-types, as well as cell-types derived from the known non-NC sites of sox10 expression, including otic epithelium and oligodendrocytes. This line provides an invaluable tool for the further study of zebrafish NC development and NC-derived stem cells as well as that of the otic vesicle and oligodendrocytes. PMID:22522888

Rodrigues, Frederico S L M; Doughton, Gail; Yang, Bingjie; Kelsh, Robert N

2012-05-14

112

A col10a1:nlGFP transgenic line displays putative osteoblast precursors at the medaka notochordal sheath prior to mineralization.  

PubMed

In teleosts, such as medaka, ossification of the vertebral column starts with the mineralization of the notochordal sheath in a segmental pattern. This establishes the chordal centrum, which serves as the basis for further ossifications by sclerotome derived osteoblasts generating the vertebral body. So far, it is unclear which cells produce the notochordal sheath and how a segmental pattern of mineralization is established in teleosts. Here, we use a transgenic medaka line that expresses nlGFP under the control of the col10a1 promoter for in vivo analysis of vertebral body formation. We show that col10a1:nlGFP expression recapitulates endogenous col10a1 expression. In the axial skeleton, col10a1:nlGFP cells appear prior to the mineralization of the notochordal sheath in a segmental pattern. These cells remain on the outer surface of the chordal centra during mineralization as well as subsequent perichordal ossification of the vertebral bodies. Using twist1a1:dsRed and osx:mCherry transgenic lines we show that a subset of col10a1:nlGFP cells is derived from sclerotomal precursors and differentiates into future osteoblasts. For the first time, this shows a segmental occurrence of putative osteoblast precursors in the vertebral centra prior to ossification of the notochordal sheath. This opens the possibility that sclerotome derived cells in teleosts are implicated in the establishment of the mineralized vertebral column in a similar manner as previously described for tetrapods. PMID:23769979

Renn, Jörg; Büttner, Anita; To, Thuy Thanh; Chan, Sherlynn Jin Hui; Winkler, Christoph

2013-06-13

113

Transgenic sorghum plants via microprojectile bombardment.  

PubMed Central

Transgenic sorghum plants have been obtained after microprojectile bombardment of immature zygotic embryos of a drought-resistant sorghum cultivar, P898012. DNA delivery parameters were optimized based on transient expression of R and C1 maize anthocyanin regulatory elements in scutellar cells. The protocol for obtaining transgenic plants consists of the delivery of the bar gene to immature zygotic embryos and the imposition of bialaphos selection pressure at various stages during culture, from induction of somatic embryogenesis to rooting of regenerated plantlets. One in about every 350 embryos produced embryogenic tissues that survived bialaphos treatment; six transformed callus lines were obtained from three of the eight sorghum cultivars used in this research. Transgenic (T0) plants were obtained from cultivar P898012 (two independent transformation events). The presence of the bar and uidA genes in the T0 plants was confirmed by Southern blot analysis of genomic DNA. Phosphinothricin acetyltransferase activity was detected in extracts of the T0 plants. These plants were resistant to local application of the herbicide Ignite/Basta, and the resistance was inherited in T1 plants as a single dominant locus. Images Fig. 1 Fig. 2 Fig. 4 Fig. 5

Casas, A M; Kononowicz, A K; Zehr, U B; Tomes, D T; Axtell, J D; Butler, L G; Bressan, R A; Hasegawa, P M

1993-01-01

114

Analyses of single-copy Arabidopsis T-DNA-transformed lines show that the presence of vector backbone sequences, short inverted repeats and DNA methylation is not sufficient or necessary for the induction of transgene silencing  

PubMed Central

In genetically transformed plants, transgene silencing has been correlated with multiple and complex insertions of foreign DNA, e.g. T-DNA and vector backbone sequences. Occasionally, single-copy transgenes also suffer transgene silencing. We have compared integration patterns and T-DNA/plant DNA junctions in a collection of 37 single-copy T-DNA-transformed Arabidopsis lines, of which 13 displayed silencing. Vector sequences were found integrated in five lines, but only one of these displayed silencing. Truncated T-DNA copies, positioned in inverse orientation to an intact T-DNA copy, were discovered in three lines. The whole nptII gene with pnos promoter was present in the truncated copy of one such line in which heavy silencing has been observed. In the two other lines no silencing has been observed over five generations. Thus, vector sequences and short additional T-DNA sequences are not sufficient or necessary to induce transgene silencing. DNA methylation of selected restriction endonuclease sites could not be correlated with silencing. Our collection of T-DNA/plant DNA junctions has also been used to evaluate current models of T-DNA integration. Data for some of our lines are compatible with T-DNA integration in double-strand breaks, while for others initial invasion of plant DNA by the left or by the right T-DNA end seem important.

Meza, Trine J.; Stangeland, Biljana; Mercy, Inderjit S.; Skarn, Magne; Nymoen, Dag A.; Berg, Anita; Butenko, Melinka A.; Hakelien, Anne-Mari; Haslekas, Camilla; Meza-Zepeda, Leonardo A.; Aalen, Reidunn B.

2002-01-01

115

An indicator gene for detection of germline retrotransposition in transgenic Drosophila demonstrates RNA-mediated transposition of the LINE I element.  

PubMed Central

We have marked a cloned Drosophila transposable element--the I element--with an engineered neomycin-containing indicator gene, whose expression is conditioned by passage of the transposon through an RNA intermediate. Mobility of the marked element introduced into Drosophila as a transgene could be detected in vivo, upon in toto selection of developing embryos on G418-containing medium. For resistant individuals, Southern blot analysis and nucleotide sequencing after PCR amplification disclosed transposition of the marked element into new loci, with target site duplications and splicing out of the intron in the indicator gene. It demonstrates that the I element, which is closely related to the widespread mammalian LINEs, transposes through an RNA intermediate, as up to now only conjectured from sequence singularities of this class of 'non-viral retrotransposons'. The developed indicator gene provides a potent new genetic tool for detection and quantitative analysis of retrotransposon mobility and its regulation as it occurs in vivo. Images

Jensen, S; Heidmann, T

1991-01-01

116

Direct Derivation of Conditionally Immortal Cell Lines from an H-2K^b- tsA58 Transgenic Mouse  

Microsoft Academic Search

Studies on cell lines have greatly improved our understanding of many important biological questions. Generation of cell lines is facilitated by the introduction of immortalizing oncogenes into cell types of interest. One gene known to immortalize many different cell types in vitro encodes the simian virus 40 (SV40) large tumor (T) antigen (TAg). To circumvent the need for gene insertion

Parmjit S. Jat; Mark D. Noble; Yujiro Tanaka; Nikos Yannoutsos; Lena Larsen; Dimitris Kioussis

1991-01-01

117

Novel mast cell lines with enhanced proliferative and degranulative abilities established from temperature-sensitive SV40 large T antigen transgenic mice.  

PubMed

Mast cells (MCs) play crucial roles in innate immunity to parasitic and bacterial infections as well as in hypersensitivity, such as the induction and exacerbation of allergy and autoimmune diseases. The regulatory mechanisms for MC development and effector functions are of great interest for developing novel therapeutic strategies against such disorders. Here we report the establishment of novel, immortalized MC lines from bone marrow (BM) cells of a temperature-sensitive mutant of SV40 large T antigen-transgenic mice (termed SVMCs). BM cells from tsSV40LT mice were cultured in the presence of interleukin (IL)-3 for 3 weeks, and then subjected to limiting dilution and single-cell cloning, yielding 27 independent MC clones, three of which were subjected to further analysis. On culture with nerve growth factor, stem cell factor and IL-3, these SVMC clones showed morphologic and biochemical changes from mucosal MC-like to connective-tissue MC-like phenotypes. These SVMC lines exhibited a significantly enhanced proliferation rate, and a higher responsiveness to the high affinity Fc receptor for IgE-mediated intracellular calcium mobilization and degranulation than those of BM-derived cultured MCs. These cell lines should facilitate studies on the mechanisms for the development, differentiation and effector functions of MCs in health and diseases. PMID:16822814

Kanehira, Masahiko; Kaifu, Tomonori; Maya, Kozue; Kaji, Mitsuji; Nakamura, Akira; Obinata, Masuo; Takai, Toshiyuki

2006-07-05

118

Relationships between intermediate filaments and cell-specific functions in renal cell lines derived from transgenic mice harboring the temperature-sensitive T antigen.  

PubMed

Four renal cell lines were derived from glomeruli, proximal, distal, and cortical collecting tubules microdissected from the kidneys of transgenic mice carrying the temperature-sensitive mutant of the simian virus 40 large T antigen under the control of the vimentin promoter. All four cell lines contained large T antigen in their nuclei, grew rapidly, and contained vimentin filaments when grown in serum-enriched medium at the permissive temperature of 33 degrees C. The glomerular cell line formed multiple layers of cells and contained smooth muscle actin and desmin filaments, features of mesangial cells. The three tubule cell lines formed monolayers of polarized cuboid cells separated by tight junctions and having a patchy distribution of cytokeratins K8-K18. A shift from 33 degrees C to the restrictive temperature (39.5 degrees C) stopped cell growth in all cell lines and caused profound changes in the content of intermediate filaments. Vimentin was still present in mesangial-like cells, but the proximal, distal, and collecting tubule cells contained uniform networks of cytokeratins K8-K18 and desmoplakin I and II around the cell peripheries. Potassium transport, mediated by Na+-K+ ATPase pumps and specific cAMP hormonal sensitivities, significantly increased in proximal, distal, and collecting tubule cells when shifted from 33 degrees C to 39.5 degrees C. Thus, the temperature-dependent inactivation of large T antigen, responsible for the arrest of cell growth, did not affect the phenotype of mesangial-like glomerular cells but induced some changes in the expression of intermediate filaments and restored, at least partially, the main parental cell-specific functions in proximal, distal, and collecting tubule cultured cells. PMID:8698837

Cluzeaud, F; Bens, M; Wu, M S; Li, Z; Vicart, P; Paulin, D; Vandewalle, A

1996-04-01

119

Enhanced ascorbic acid accumulation in transgenic potato confers tolerance to various abiotic stresses.  

PubMed

L-ascorbic acid (Vitamin C, AsA) is an important component of human nutrition. Plants and several animals can synthesize their own ascorbic acid, whereas humans lack the gene essential for ascorbic acid biosynthesis and must acquire from their diet. In the present study, we developed transgenic potato (Solanum tuberosum L. cv. Taedong Valley) over-expressing L-gulono-gamma-lactone oxidase (GLOase gene; NCBI Acc. No. NM022220), isolated from rat cells driven by CaMV35S constitutive promoter that showed enhanced AsA accumulation. Molecular analyses of four independent transgenic lines performed by PCR, Southern and RT-PCR revealed the stable integration of the transgene in the progeny. The transformation frequency was ca. 7.5% and the time required for the generation of transgenic plants was 6-7 weeks. Transgenic tubers showed significantly enhanced AsA content (141%) and GLOase activity as compared to untransformed tubers. These transgenics were also found to withstand various abiotic stresses caused by Methyl Viologen (MV), NaCl or mannitol, respectively. The T(1) transgenic plants exposed to salt stress (100 mM NaCl) survived better with increased shoot and root length when compared to untransformed plants. The elevated level of AsA accumulation in transgenics was directly correlated with their ability to withstand abiotic stresses. These results further demonstrated that the overexpression of GLOase gene enhanced basal levels of AsA in potato tubers and also the transgenics showed better survival under various abiotic stresses. PMID:19821071

Hemavathi; Upadhyaya, Chandrama Prakash; Akula, Nookaraju; Young, Ko Eun; Chun, Se Chul; Kim, Doo Hwan; Park, Se Won

2009-10-11

120

Analysis of T-DNA integration and generative segregation in transgenic winter triticale (x Triticosecale Wittmack)  

PubMed Central

Background While the genetic transformation of the major cereal crops has become relatively routine, to date only a few reports were published on transgenic triticale, and robust data on T-DNA integration and segregation have not been available in this species. Results Here, we present a comprehensive analysis of stable transgenic winter triticale cv. Bogo carrying the selectable marker gene HYGROMYCIN PHOSPHOTRANSFERASE (HPT) and a synthetic green fluorescent protein gene (gfp). Progeny of four independent transgenic plants were comprehensively investigated with regard to the number of integrated T-DNA copies, the number of plant genomic integration loci, the integrity and functionality of individual T-DNA copies, as well as the segregation of transgenes in T1 and T2 generations, which also enabled us to identify homozygous transgenic lines. The truncation of some integrated T-DNAs at their left end along with the occurrence of independent segregation of multiple T-DNAs unintendedly resulted in a single-copy segregant that is selectable marker-free and homozygous for the gfp gene. The heritable expression of gfp driven by the maize UBI-1 promoter was demonstrated by confocal laser scanning microscopy. Conclusions The used transformation method is a valuable tool for the genetic engineering of triticale. Here we show that comprehensive molecular analyses are required for the correct interpretation of phenotypic data collected from the transgenic plants.

2012-01-01

121

Testing Transgenic Spring Wheat and Barley Lines for Reaction to Fusarium Head Blight: 2009 Field Nursery Report  

Technology Transfer Automated Retrieval System (TEKTRAN)

The 2009 field screening nursery, with 128 wheat and 208 barley plots was located at UMore Park, Rosemount MN. Trial entries and untransformed controls were submitted by the University of Minnesota (19+1 wheat), the Donald Danforth Plant Science Center (4+2 wheat) and USDA (48+1 barley). Lines wit...

122

Pathogenic bacteria induce colonic PepT1 expression: an implication in host defense response  

PubMed Central

Background & Aims Expression of the di/tripeptide transporter PepT1 has been observed in the colon under inflammatory conditions, however, the inducing factors and underlying mechanisms remain unknown. Here, we address the effects of pathogenic bacteria on colonic PepT1 expression together with its functional consequences. Methods Human colonic HT29-Cl.19A cells were infected with the attaching and effacing (A/E) enteropathogenic E. coli (EPEC). Wild-type and PepT1 transgenic mice or cultured colonic tissues derived from these mice were infected with Citrobacter rodentium, a murine A/E pathogen related to EPEC. Results EPEC induced PepT1 expression and activity in HT29-Cl.19A cells by intimately attaching to host cells through lipid rafts. Induction of PepT1 expression by EPEC required the transcription factor Cdx2. PepT1 expression reduced binding of EPEC to lipid rafts, as well as activation of NF-?B and MAP kinase and production of IL-8. Accordingly, ex vivo and in vivo experiments revealed that C. rodentium induced colonic PepT1 expression and that, compared to their wild-type counterparts, PepT1 transgenic mice infected with C. rodentium exhibited decreased bacterial colonization, production of pro-inflammatory cytokines, and neutrophil infiltration into the colon. Conclusions Our findings demonstrate a molecular mechanism underlying the regulation of colonic PepT1 expression under pathological conditions and reveal a novel role for PepT1 in host defense via its capacity to modulate bacterial-epithelial interactions and intestinal inflammation.

Nguyen, Hang Thi Thu; Dalmasso, Guillaume; Powell, Kimberly R.; Yan, Yutao; Bhatt, Shantanu; Kalman, Daniel; Sitaraman, Shanthi; Merlin, Didier

2009-01-01

123

Generation of a conditionally neor-containing retroviral producer cell line: effects of neor on retroviral titer and transgene expression  

Microsoft Academic Search

We have developed a method for generating high-titer retroviral producer cell lines conditionally containing a neomycin resistance gene (neor) based on the Cre\\/loxP system. For this, a bicistronic retroviral splicing vector carrying the green fluorescence protein (GFP) and a marker gene cassette consisting of internal ribosome entry site (IRES) and neor flanked by loxP sites, was constructed and conveniently used

O Wildner; F Candotti; EG Krecko; KG Xanthopoulos; WJ Ramsey; RM Blaese

1998-01-01

124

All-trans retinoic acid inhibits KIT activity and induces apoptosis in gastrointestinal stromal tumor GIST-T1 cell line by affecting on the expression of survivin and Bax protein  

Microsoft Academic Search

BACKGROUND: Imatinib, a selective tyrosine kinase inhibitor, has been used as a standard first-line therapy for irresectable and metastasized gastrointestinal stromal tumor (GIST) patients. Unfortunately, most patients responding to imatinib will eventually exhibit imatinib-resistance, the cause of which is not fully understood. The serious clinical problem of imatinib-resistance demands alternative therapeutic strategy. This study was conducted to investigate the effect

Hoang Thanh Chi; Bui Thi Kim Ly; Takahiro Taguchi; Toshiki Watanabe; Yuko Sato

2010-01-01

125

Establishment and characterization of murine small cell lung carcinoma cell lines derived from HPV-16 E6/E7 transgenic mice.  

PubMed

We have established two murine cell lines derived from Small Cell Lung Carcinomas (SCLCs) developed by HPV-E6/E7 transgenic mice. These cells named PPAP-9 and PPAP-10 were isolated from mice bearing tumors, 9 and 10 months old, respectively. The cells, 5 microm in diameter, express HPV oncoproteins and sustain tumor formation after subcutaneous injection in syngenic mice. A detailed analysis indicated the epithelial origin and the neuroendocrine differentiation of these cells. We showed by confocal immunofluorescence the expression of the epithelial marker cytokeratin 5, whose gene promoter was used to direct the expression of HPV E6/E. Cells express several neuroendocrine markers such as CGRP, MAP-2, Ash1, CgrA, Scg2. The neuroendocrine differentiation of these cells was further confirmed by electron microscopy demonstrating neuropeptides secreting granules in their cytoplasm. Furthermore, in agreement with the altered expression observed in the majority of human SCLC we showed in these cells the absence of both p53 and pRB and a dramatic reduction in the expression of Caveolin-1. PMID:16356832

Carraresi, Laura; Martinelli, Rosanna; Vannoni, Alessandro; Riccio, Massimo; Dembic, Maja; Tripodi, Sergio; Cintorino, Marcella; Santi, Spartaco; Bigliardi, Elisa; Carmellini, Mario; Rossini, Mara

2006-01-01

126

Gene stability in transgenic aspen (Populus). II. Molecular characterization of variable expression of transgene in wild and hybrid aspen.  

PubMed

In many annual plant species, transgene inactivation occurs most often when multiple incomplete/complete copies of the transgene are present in a genome. The expression of single-copy transgene loci may also be negatively influenced by the flanking plant DNA and/or chromosomal location (position effect). To understand transgene silencing in a long-lived tree system, we analyzed several wild (Populus tremula L.) and hybrid (P. tremula L. x P. tremuloides Michx.) aspen lines transgenic to the rolC phenotypical marker system and grown under in vitro, greenhouse and field conditions. The morphological features of the 35S-rolC gene construct were used to screen lines with altered transgene expression, which was later confirmed by Northern experiments. Molecular analyses of hybrid aspen revealed that transgene inactivation was always a consequence of transgene repeats. In wild non-hybrid aspen, however, multiple-insertion-based altered or loss of rolC expression was observed only in three out of six lines showing transgene inactivation. Sequencing analysis revealed AT-rich patches at the transgene flanking genomic regions of some of the wild aspen transgenic lines. One wild aspen line showing variable rolC expression revealed characteristic integration of the transgene into genomic regions containing a high AT content (85% or more). In the remaining two wild aspen transgenic lines unstable for rolC expression, single-copy integration and non-AT-rich or repeat-free transgene flanking regions were found. A partial suppression of rolC was observed in some plants of one of the field-grown wild aspen transgenic lines. In the other wild aspen transgenic line an additional mutant phenotype along with transgene inactivation was found. This indicates that the host genome has some control over expression of a transgene, and the possible role of AT-rich regions in defense against foreign DNA. PMID:11678277

Kumar, S; Fladung, M

2001-09-01

127

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

2005-01-25

128

Gene expression profile in liver of hB1F transgenic mice  

Microsoft Academic Search

AIM: To analyze the tissue morphologic phenotype and liver gene expression profile of hB1F transgenic mice. METHODS: Transgene expression was analyzed with RT- PCR and Western blotting. For one of the transgenic mouse lines, tissue expression pattern of the transgene was also examined with immunochemical methods. Pathological analysis was used to examine the tissue morphologic phenotype of established transgenic mice.

Shui-Liang Wang; Hua Yang; You-Hua Xie; Yuan Wang; Jian-Zhong Li; Long Wang; Zhu-Gang Wang; Ji-Liang Fu

2004-01-01

129

Transgenic Animals.  

ERIC Educational Resources Information Center

|Describes three methods and their advantages and disadvantages for introducing genes into animals. Discusses the predictability and tissue-specificity of the injected genes. Outlines the applications of transgenic technology for studying gene expression, the early stages of mammalian development, mutations, and the molecular nature of…

Jaenisch, Rudolf

1988-01-01

130

Transgenic chickens.  

PubMed

The development of transgenic chicken technology has lagged far behind that of mammalian species. Two reasons for this are that only a one-cell-stage oocyte can be obtained from a sacrificed hen and that the yolk prevents high-magnification microscopic observation of oocytes. Recently, several new methods have been developed that will enable the successful establishment of transgenic chickens. Retroviral vectors are used in many cases because of their ability to incorporate transgenes into host cell chromosomes in a highly efficient manner. These viral vectors are injected directly into the embryos, usually at the blastodermal stage. In some cases, primordial germ cells (PGCs) are infected in vitro and then implanted into recipient embryos. Methods that do not rely on retroviral vectors are also available for creating transgenic chickens. Long-term culture of PGCs permits the selection of stably transfected cells and implantation of the manipulated PGCs. In addition, embryonic stem (ES) cell systems are available; however, the induction of functional gametes from ES cells has not, to our knowledge, been successful. It is clear that recent developments suggest that chickens may be used as a valuable experimental genetic system. PMID:23278121

Nishijima, Ken-ichi; Iijima, Shinji

2012-12-26

131

Transgenic Animals.  

ERIC Educational Resources Information Center

Describes three methods and their advantages and disadvantages for introducing genes into animals. Discusses the predictability and tissue-specificity of the injected genes. Outlines the applications of transgenic technology for studying gene expression, the early stages of mammalian development, mutations, and the molecular nature of chromosomes.…

Jaenisch, Rudolf

1988-01-01

132

Algebraic models for T 1-spaces  

Microsoft Academic Search

We show that the T1-spaces are precisely the maximal point spaces of conditionally up-complete algebraic posets with the Scott topology. Moreover, we establish an equivalence between the category of T1-spaces with a distinguished base and a certain category of so-called camps. These are conditionally up-complete, algebraic and maximized posets in which every compact element is a meet of maximal elements,

Marcel Erné

2011-01-01

133

Improved Nutritive Quality and Salt Resistance in Transgenic Maize by Simultaneously Overexpression of a Natural Lysine-Rich Protein Gene, SBgLR, and an ERF Transcription Factor Gene, TSRF1  

PubMed Central

Maize (Zea mays L.), as one of the most important crops in the world, is deficient in lysine and tryptophan. Environmental conditions greatly impact plant growth, development and productivity. In this study, we used particle bombardment mediated co-transformation to obtain marker-free transgenic maize inbred X178 lines harboring a lysine-rich protein gene SBgLR from potato and an ethylene responsive factor (ERF) transcription factor gene, TSRF1, from tomato. Both of the target genes were successfully expressed and showed various expression levels in different transgenic lines. Analysis showed that the protein and lysine content in T1 transgenic maize seeds increased significantly. Compared to non-transformed maize, the protein and lysine content increased by 7.7% to 24.38% and 8.70% to 30.43%, respectively. Moreover, transgenic maize exhibited more tolerance to salt stress. When treated with 200 mM NaCl for 48 h, both non-transformed and transgenic plant leaves displayed wilting and losing green symptoms and dramatic increase of the free proline contents. However, the degree of control seedlings was much more serious than that of transgenic lines and much more increases of the free proline contents in the transgenic lines than that in the control seedlings were observed. Meanwhile, lower extent decreases of the chlorophyll contents were detected in the transgenic seedlings. Quantitative RT-PCR was performed to analyze the expression of ten stress-related genes, including stress responsive transcription factor genes, ZmMYB59 and ZmMYC1, proline synthesis related genes, ZmP5CS1 and ZmP5CS2, photosynthesis-related genes, ZmELIP, ZmPSI-N, ZmOEE, Zmrbcs and ZmPLAS, and one ABA biosynthesis related gene, ZmSDR. The results showed that with the exception of ZmP5CS1 and ZmP5CS2 in line 9–10 and 19–11, ZmMYC1 in line 19–11 and ZmSDR in line 19–11, the expression of other stress-related genes were inhibited in transgenic lines under normal conditions. After salt treatment, the expressions of the ten stress-related genes were significantly induced in both wild-type (WT) and transgenic lines. However, compared to WT, the increases of ZmP5CS1 in all these three transgenic lines and ZmP5CS2 in line 9–10 were less than WT plants. This study provides an effective approach of maize genetic engineering for improved nutritive quality and salt tolerance.

Wang, Meizhen; Liu, Chen; Li, Shixue; Zhu, Dengyun; Zhao, Qian; Yu, Jingjuan

2013-01-01

134

Improved Nutritive Quality and Salt Resistance in Transgenic Maize by Simultaneously Overexpression of a Natural Lysine-Rich Protein Gene, SBgLR, and an ERF Transcription Factor Gene, TSRF1.  

PubMed

Maize (Zea mays L.), as one of the most important crops in the world, is deficient in lysine and tryptophan. Environmental conditions greatly impact plant growth, development and productivity. In this study, we used particle bombardment mediated co-transformation to obtain marker-free transgenic maize inbred X178 lines harboring a lysine-rich protein gene SBgLR from potato and an ethylene responsive factor (ERF) transcription factor gene, TSRF1, from tomato. Both of the target genes were successfully expressed and showed various expression levels in different transgenic lines. Analysis showed that the protein and lysine content in T1 transgenic maize seeds increased significantly. Compared to non-transformed maize, the protein and lysine content increased by 7.7% to 24.38% and 8.70% to 30.43%, respectively. Moreover, transgenic maize exhibited more tolerance to salt stress. When treated with 200 mM NaCl for 48 h, both non-transformed and transgenic plant leaves displayed wilting and losing green symptoms and dramatic increase of the free proline contents. However, the degree of control seedlings was much more serious than that of transgenic lines and much more increases of the free proline contents in the transgenic lines than that in the control seedlings were observed. Meanwhile, lower extent decreases of the chlorophyll contents were detected in the transgenic seedlings. Quantitative RT-PCR was performed to analyze the expression of ten stress-related genes, including stress responsive transcription factor genes, ZmMYB59 and ZmMYC1, proline synthesis related genes, ZmP5CS1 and ZmP5CS2, photosynthesis-related genes, ZmELIP, ZmPSI-N, ZmOEE, Zmrbcs and ZmPLAS, and one ABA biosynthesis related gene, ZmSDR. The results showed that with the exception of ZmP5CS1 and ZmP5CS2 in line 9-10 and 19-11, ZmMYC1 in line 19-11 and ZmSDR in line 19-11, the expression of other stress-related genes were inhibited in transgenic lines under normal conditions. After salt treatment, the expressions of the ten stress-related genes were significantly induced in both wild-type (WT) and transgenic lines. However, compared to WT, the increases of ZmP5CS1 in all these three transgenic lines and ZmP5CS2 in line 9-10 were less than WT plants. This study provides an effective approach of maize genetic engineering for improved nutritive quality and salt tolerance. PMID:23629675

Wang, Meizhen; Liu, Chen; Li, Shixue; Zhu, Dengyun; Zhao, Qian; Yu, Jingjuan

2013-04-29

135

Quantitative trait loci affecting cotton fiber are linked to the t 1 locus in upland cotton  

Microsoft Academic Search

Pilose (T1), a dominant marker in upland cotton, has been associated with coarse, short fibers. Pilose was, thereby, considered to be pleiotropic on fiber fineness and length. However, a pilose-expressing line with a fiber of average fineness was recently identified. This finding does not support pleiotropy between T1 and fiber traits, but is indicative of linkage between pilose and loci

R. H. Kloth

1995-01-01

136

A model for the mechanism of precise integration of a microinjected transgene  

Microsoft Academic Search

A unique transgenic mouse line has undergone transgene integration in a very precise fashion. The phenotype displayed by mice of the line followed the predicted inheritance patterns for X-linked transgene insertion which has been confirmed. In order to investigate the mechanism of integration the DNA sequence of the transgene and cellular junctions have been determined. A comparison between wild type

Morag McFarlane; Joanna B. Wilson

1996-01-01

137

Genomic stability and long-term transgene expression in poplar.  

PubMed

Stable expression of foreign genes over the entire life span of a plant is important for long-lived organisms such as trees. For transgenic forest trees, very little information is available on long-term transgene expression and genomic stability. Independent transgenic lines obtained directly after transformation are initially screened in respect to T-DNA integration and transgene expression. However, very little consideration has been given to long-term transgene stability in long-lived forest trees. We have investigated possible genome wide changes following T-DNA integration as well as long-term stability of transgene expression in different transgenic lines of hybrid aspen (Populus tremula × Populus tremuloides) that are up to 19 years old. For studies on possible genome wide changes following T-DNA integration, four different independent rolC-transgenic lines were subjected to an extensive AFLP study and compared to the non-transgenic control line. Only minor genomic changes following T-DNA integration could be detected. To study long-term transgene expression, six different independent rolC-transgenic lines produced in 1993 and since that time have been kept continuously under in vitro conditions. In addition, 18 transgenic plants belonging to eight independent rolC-transgenic lines transferred to glasshouse between 1994 and 2004 were chosen to determine the presence and expression of the rolC gene. In all transgenic lines examined, the rolC gene could successfully be amplified by PCR tests. Both, the 19 years old tissue cultures and the up to 18 years old glasshouse-grown trees revealed expression of the rolC transgene, as demonstrated by the rolC-phenotype and/or northern blot experiments confirming long-term transgene expression. PMID:23740206

Fladung, Matthias; Hoenicka, Hans; Raj Ahuja, M

2013-06-01

138

New pulse sequences for T1- and T1/T2-contrast enhancing in NMR imaging.  

PubMed

Improved pulse sequences DIFN (abbreviation of the words: DIFferentiation by N pulses), 90 degrees - tau1 - 180 degrees tau1 - . . . 180 degrees - tau1 with optimised time intervals tau1- for T1 measurement and contrast enhancing in NMR imaging are presented. The pulse sequences DIFN have a better sensitivity to T1 than the well-known pulse sequence SR. In contrast to the IR pulse sequence, the information given by the DIFN pulse sequence is more reliable, because the NMR signal does not change its sign. For a given time interval tau0 < or = (0.1 - 0.3) T(1) the DIFN pulse sequences serve as T1-filters. They pass the signal components with relatively short T1 < T(1) and suppress the components with relatively long T1 < T(1). The effects of the radiofrequency field inhomogeneity and inaccurate adjusting of pulse lengths are also considered. It is also proposed in this work to use the joint T1T2-contrast in NMR imaging obtained as a result of applying the DIFN pulse sequences in combination with the well-known Carr-Purcell-Meiboom-Gill (CPMG) pulse sequence. The region of interest, where the contrast should be especially enhanced, is specified by the two times at which measurements are performed, which allow the amplitudes of pixels to reach some defined levels by spin-lattice and spin-spin relaxation. PMID:9814781

Andreev, N K; Hakimov, A M; Idiyatullin, D S

1998-10-01

139

Monitoring changes in anthocyanin and steroid alkaloid glycoside content in lines of transgenic potato plants using liquid chromatography\\/mass spectrometry  

Microsoft Academic Search

Transgenic potato plants overexpressing and repressing enzymes of flavonoids biosynthesis were created and analyzed. The selected plants clearly showed the expected changes in anthocyanins synthesis level. Overexpression of a DNA encoding dihydroflavonol 4-reductase (DFR) in sense orientation resulted in an increase in tuber anthocyanins, a 4-fold increase in petunidin and pelargonidin derivatives. A significant decrease in anthocyanin level was observed

Maciej Stobiecki; Iwona Matysiak-Kata; Rafa? Fra?ski; Jacek Ska?a; Jan Szopa

2003-01-01

140

The H-2K b tsA58 transgenic mouse: A new tool for the rapid generation of novel cell lines  

Microsoft Academic Search

The ability to generate expanded populations of individual cell types able to undergo normal differentiationin vitro andin vivo is of critical importance in the investigation of the mechanisms that underly differentiation and in studies on the use of cell transplantation to repair damaged tissues. This review discusses the development of a strain of transgenic mice that allows the direct derivation

Mark Noble; Andrew K. Groves; Zebbie Ikram; Parmjit S. Jat

1995-01-01

141

Strategies for designing transgenic DNA constructs.  

PubMed

Generation and characterization of transgenic mice are important elements of biomedical research. In recent years, transgenic technology has become more versatile and sophisticated, mainly because of the incorporation of recombinase-mediated conditional expression and targeted insertion, site-specific endonuclease-mediated genome editing, siRNA-mediated gene knockdown, various inducible gene expression systems, and fluorescent protein marking and tracking techniques. Site-specific recombinases (such as PhiC31) and engineered endonucleases (such as ZFN and Talen) have significantly enhanced our ability to target transgenes into specific genomic loci, but currently a great majority of transgenic mouse lines are continuingly being created using the conventional random insertion method. A major challenge for using this conventional method is that the genomic environment at the integration site has a substantial influence on the expression of the transgene. Although our understanding of such chromosomal position effects and our means to combat them are still primitive, adhering to some general guidelines can significantly increase the odds of successful transgene expression. This chapter first discusses the major problems associated with transgene expression, and then describes some of the principles for using plasmid and bacterial artificial chromosomes (BACs) for generating transgenic constructs. Finally, the strategies for conducting each of the major types of transgenic research are discussed, including gene overexpression, promoter characterization, cell-lineage tracing, mutant complementation, expression of double or multiple transgenes, siRNA knockdown, and conditional and inducible systems. PMID:23912987

Liu, Chengyu

2013-01-01

142

Immiscible fluids permeability by T1 imaging.  

PubMed

Soil pollution by hydrocarbon compounds is an important part of the more general pollution problem. Some analogies with research problems encountered in studies of oil reservoirs in rocks suggested to us the opportunity to study the pollution dynamics by imaging the spatial distribution of the pollutant in a wet soil model by an NMR imaging technique. Some preliminary results using T1-weighted imaging are reported here. PMID:1461079

Casieri, C; De Angelis, C; De Luca, F; Garreffa, G; Maraviglia, B

1992-01-01

143

Inert fluorinated gas T1 calculator  

NASA Astrophysics Data System (ADS)

The physics of spin-rotation interaction in roughly spherical perfluorinated gas molecules has been studied extensively. But, it is difficult to calculate a spin-lattice relaxation time constant T1 for any given temperature and pressure using the published literature. We give a unified parameterization that makes use of the Clausius equation of state, Lennard-Jones collision dynamics, and a formulaic temperature dependence for collision cross section for rotational change. The model fits T1s for SF6, CF4, C2F6, and c-C4F8 for temperatures from 180 to 360 K and pressures from 2 to 210 kPa and in mixtures with other common gases to within our limits of measurement. It also fits previous data tabulated according to known number densities. Given a pressure, temperature, and mixture composition, one can now calculate T1s for common laboratory conditions with a known accuracy, typically 0.5%. Given the success of the model’s formulaic structure, it is likely to apply to even broader ranges of physical conditions and to other gases that relax by spin-rotation interaction.

Kuethe, Dean O.; Pietraß, Tanja; Behr, Volker C.

2005-12-01

144

Highly scab-resistant transgenic apple lines achieved by introgression of HcrVf2 controlled by different native promoter lengths  

Microsoft Academic Search

Apple scab, caused by the ascomycete Venturia inaequalis, is the most damaging fungal disease of commercial apple orchards. Functional scab resistance genes are present in some wild\\u000a Malus species. The HcrVf2 gene, derived from the Vf-region of the wild apple Malus floribunda 821 and encoding a receptor-like protein, has proved to confer scab resistance in a transgenic susceptible cultivar. In

Iris Szankowski; Sascha Waidmann; Juliana Degenhardt; Andrea Patocchi; Roberta Paris; Eve Silfverberg-Dilworth; Giovanni Broggini; Cesare Gessler

2009-01-01

145

Transgenic rice as a system to study the stability of transgene expression: multiple heterologous transgenes show similar behaviour in diverse genetic backgrounds  

Microsoft Academic Search

The success of contemporary breeding programmes involving genetic engineering depends on the stability of transgene expression\\u000a over many generations. We studied the stability of transgene expression in 40 independent rice plant lines representing 11\\u000a diverse cultivated varieties. Each line contained three or four different transgenes delivered by particle bombardment, either\\u000a by cotransformation or in the form of a cointegrate vector.

D. Gahakwa; S. B. Maqbool; X. Fu; D. Sudhakar; P. Christou; A. Kohli

2000-01-01

146

Inorganic nanoparticle-based T1 and T1/T2 magnetic resonance contrast probes.  

PubMed

Magnetic resonance imaging (MRI) yields high spatially resolved contrast with anatomical details for diagnosis, deeper penetration depth and rapid 3D scanning. To improve imaging sensitivity, adding contrast agents accelerates the relaxation rate of water molecules, thereby greatly increasing the contrast between specific issues or organs of interest. Currently, the majority of T(1) contrast agents are paramagnetic molecular complexes, typically Gd(iii) chelates. Various nanoparticulate T(1) and T(1)/T(2) contrast agents have recently been investigated as novel agents possessing the advantages of both the T(1) contrast effect and nanostructural characteristics. In this minireview, we describe the recent progress of these inorganic nanoparticle-based MRI contrast agents. Specifically, we mainly report on Gd and Mn-based inorganic nanoparticles and ultrasmall iron oxide/ferrite nanoparticles. PMID:22971876

Hu, Fengqin; Zhao, Yong Sheng

2012-10-21

147

Development of insect-resistant transgenic cotton with chimeric TVip3A accumulating in chloroplasts.  

PubMed

An optimized vip3A gene, designated as vip3A* was chemically synthesized and a thi1 gene chloroplast transit peptide coding sequence was attached to its 5' end to produce the tvip3A*. vip3A* and tvip3A* genes were transformed into Gossypium hirsutum cv. Zhongmiansuo35 mediated by Agrobacterium tumefaciens. Four independent transgenic T1 lines with single-copy insertions and unchanged phenotypes (CTV1 and CTV2 for tvip3A*, and CV1 and CV2 for vip3A*) were selected by Polymerase chain reaction (PCR), Reverse transcription (RT)-PCR, Southern blotting, enzyme-linked immunosorbent assay (ELISA), and insect bioassay. As expected, the Vip3A* protein of CTV1 and CTV2 were transported to the chloroplasts, where they accumulated. Our results suggest that the two tvip3A* transgenic lines (CTV1 and CTV2) can be used to develop insect-resistant cultivars and could be used as a resource for raising multi-toxins-expressing transgenic cotton. PMID:23143498

Wu, Jiahe; Tian, Yingchuan

2013-01-01

148

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

PubMed

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; Gutiérrez-Juárez, Roger; Rossetti, Luciano; Gu, Wei; Accili, Domenico

2008-10-01

149

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.

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

2011-01-01

150

Transgenic apple (Malus x domestica) shoot showing low browning potential.  

PubMed

Transgenic apple shoots were prepared from leaf disks by using Agrobacterium tumefaciens carrying the kanamycin (KM) resistance gene and antisense polyphenol oxidase (PPO) DNA. Four transgenic apple lines that grew on the medium containing 50 microgram/mL KM were obtained. They contained the KM resistance gene and grew stably on the medium for >3 years. Two transgenic shoot lines containing antisense PPO DNA in which PPO activity was repressed showed a lower browning potential than a control shoot. PMID:11087467

Murata, M; Haruta, M; Murai, N; Tanikawa, N; Nishimura, M; Homma, S; Itoh, Y

2000-11-01

151

{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)

1995-10-01

152

On-line casein micelle disruption for downstream purification of recombinant human myelin basic protein produced in the milk of transgenic cows.  

PubMed

Downstream purification of a model recombinant protein (human myelin basic protein) from milk of transgenic cows is described. The recombinant protein was expressed as a His tagged fusion protein in the milk of transgenic cows and was found associated with the casein micellar phase. While difficulties in obtaining good recoveries were found when employing conventional micelle disruption procedures, direct capture using the cation exchanger SP Sepharose Big Beads was found successful in the extraction of the recombinant protein. Early breakthrough suggested a slow release of the recombinant protein from the micelles and dictated micelle disruption in order to obtain good yields. A new approach for deconstruction of the calcium core of the casein micelles, employing the interaction between the micellar calcium and the active sites of the cation exchanger resin was developed. Milk samples were loaded to the column in aliquots with a column washing step after each aliquot. This sequential loading approach successfully liberated the recombinant protein from the micelles and was found superior to the conventional sample loading approach. It increased the recovery by more than 25%, reduced fouling due to milk components and improved the column hydrodynamic properties as compared to the conventional sample loading approach. Hardware and software modifications to the chromatography system were necessary in order to keep the whole process automated. A second purification step using a Ni2+ affinity column was used to isolate the recombinant protein at purity more than 90% and a recovery percentage of 78%. PMID:19419911

Al-Ghobashy, Medhat A; Williams, Martin A K; Brophy, Brigid; Laible, Götz; Harding, David R K

2009-04-09

153

Development of functional B cells in a line of SCID mice with transgenes coding for anti-double-stranded DNA antibody.  

PubMed

Deletion or inactivation of anti-self (DNA) B cells has been reported in non-autoimmune mice bearing Ig transgenes that code for Abs with specificity for dsDNA or ssDNA. However, we report a case in which anti-dsDNA B cells appear to escape both deletion and inactivation. We show that B cells (B220+IgM+) can develop in non-autoimmune SCID mice bearing two site-directed transgenes, 3H9(56R) and Vkappa8, that together code for an anti-dsDNA Ab. The B cells appear inactive, because the mice (56RVkappa8 SCID mice) generally lack serum Ig. However, 56RVkappa8 SCID mice are able to produce IgG Ab with specificity for dsDNA when they become "leaky" for T cells or are reconstituted with exogenous T cells from B cell-deficient JH-/- donors. Thus, anti-dsDNA B cells that escape deletion in 56RVkappa8 SCID mice appear fully functional and can differentiate, class switch, and give rise to IgG-producing cells in the presence of T cells and self-Ag. PMID:16393973

Bosma, Gayle C; Oshinsky, Jennifer; Kiefer, Kerstin; Nakajima, Pamela B; Charan, Deepshika; Congelton, Cecil; Radic, Marko; Bosma, Melvin J

2006-01-15

154

Expression of the Shpx2 peroxidase gene of Stylosanthes humilis in transgenic tobacco leads to enhanced resistance to Phytophthora parasitica pv. nicotianae and Cercospora nicotianae.  

PubMed

Abstract Previous research indicated that the constitutive expression of a pathogen-inducible peroxidase gene (Shpx6a) from Stylosanthes humilis in transgenic plants resulted in enhanced resistance to fungal pathogens ( Kazan, K., Goulter, K.C., Way, H.M. and Manners, J.M. (1998) Expression of a pathogenesis-related peroxidase of Stylosanthes humilis in transgenic tobacco and canola and its effect on disease development. Plant Sci. 136, 207-217). We have now investigated another pathogen-inducible peroxidase gene of S. humilis, termed Shpx2, which is highly divergent from Shpx6a. Constitutive expression of the Shpx2 cDNA was obtained in tobacco using the 35S CaMV promoter, and up to a 12-fold increase in total peroxidase activity was observed in the leaves of transgenic plants compared to nontransgenic controls. Disease development was evaluated after inoculations in T(1) and T(2) transgenic lines expressing Shpx2. Lesion expansion was significantly (P < 0.05) reduced by up to 25% and 50% on leaves and stems, respectively, of transgenic plants expressing high levels of peroxidase compared to nontransgenic controls, following inoculation with Phytophthora parasitica pv. nicotianae, the cause of black shank disease. In addition, plant survival and recovery were greatly enhanced in transgenic plants following stem inoculations of plants with this plant pathogen. A significant (55%, P < 0.05) reduction in lesion number was observed in transgenic plants with high levels of peroxidase activity following inoculation with the fungus Cercospora nicotianae, the cause of frog-eye disease. No significant differences in disease development were observed between the lines expressing Shpx2 and controls following inoculation with the bacterium Pseudomonas syringae pv. tabaci, the cause of wildfire disease. These results provide evidence for a role for this peroxidase gene in plant defence, and suggest that diverse peroxidase genes may be employed as components of strategies aimed at the engineering of disease resistance. PMID:20572969

Way, H M; Kazan, K; Goulter, K C; Birch, R G; Manners, J M

2000-07-01

155

[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

156

Ectopic overexpression of vacuolar and apoplastic Catharanthus roseus peroxidases confers differential tolerance to salt and dehydration stress in transgenic tobacco.  

PubMed

CrPrx and CrPrx1 are class III peroxidases previously cloned and characterized from Catharanthus roseus. CrPrx is known to be apoplastic in nature, while CrPrx1 is targeted to vacuoles. In order to study their role in planta, these two peroxidases were expressed in Nicotiana tabacum. The transformed plants exhibited increased peroxidase activity. Increased oxidative stress tolerance was also observed in transgenics when treated with H(2)O(2) under strong light conditions. However, differential tolerance to salt and dehydration stress was observed during germination of T1 transgenic seeds. Under these stresses, the seed germination of CrPrx-transformed plants and wild-type plants was clearly suppressed, whereas CrPrx1 transgenic lines showed improved germination. CrPrx-transformed lines exhibited better cold tolerance than CrPrx1-transformed lines. These results indicate that vacuolar peroxidase plays an important role in salt and dehydration stress over cell wall-targeted peroxidase, while cell wall-targeted peroxidase renders cold stress tolerance. PMID:21643888

Kumar, Santosh; Jaggi, Monika; Sinha, Alok Krishna

2011-06-04

157

Using real-time PCR to determine transgene copy number in wheat  

Microsoft Academic Search

Transgene copy number is usually determined by means of Southern blot analysis which can be time consuming and laborious.\\u000a In this study, quantitative real-time PCR was developed to determine transgene copy number in transgenic wheat. A conserved\\u000a wheat housekeeping gene,puroindoline-b, was used as an internal control to calculate transgene copy number. Estimated copy number in transgenic lines using real-time\\u000a quantitative

Zhiwu Li; Jennifer L. Hansen; Ying Liu; Robert S. Zemetra; Philip H. Berger

2004-01-01

158

Studies on the Star Association Cyg T 1 Untersuchungen ueber die Sternassoziation Cyg T 1.  

National Technical Information Service (NTIS)

After a detailed discussion of the qualities of the astrograph 300/1500 of the Observatorium Hoher List, the results of photometric investigations of the T-association Cyg T 1 are presented. These investigations are based on a great number of patrol plate...

F. Gieseking

1973-01-01

159

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

160

[Study on the transgenic tobacco expressing truncated wheat cold shock protein gene TA3-13 and analysis of disease resistance].  

PubMed

TA3-13 is a truncated gene coding for the fragment of wheat (Triticum aestivum L.) cold shock protein WCP1. It has been shown previously that the procaryotically expressed TA3-13 can induce resistance to Tobacco mosaic virus (TMV) when sprayed onto plant leaves. In this study, we constructed an expression vector pB-3-13 by cloning TA3-13 into the bionary vector pBI121 and transformed it into Agrobacterium tumefaciense strain EHA105 via freeze-thaw method. Tobacco (Nicotiana tobacum cv. Xanthi nc.) transformation was performed using the leaf disc infection method. After screening on MS medium containing kanamycin and PCR analysis, 33 T0 plantlets were identified as transgenic. Seeds from twenty T0 plants were collected and planted as T1 lines. Two T1 lines were selected for further characterization. PCR and GUS staining analysis showed that TA3-13 was integrated into the T1 tobacco genome and expressed. When inoculated on leaves, the transgenic tobacco showed significant resistance against TMV and rot pathogen Pectobactrium carotovorum subsp. carotovorum. These results suggest that the expression of TA3-13 in tobacco can induce defense responses to pathogen infection. PMID:21586399

Li, Na; DU, Xiu-Zhen; Pan, Xiao-Mei; Wang, Jin-Sheng; Song, Cong-Feng

2011-05-01

161

P-Element repression in Drosophila melanogaster by variegating clusters of P-lacZ-white transgenes.  

PubMed Central

In Drosophila, clusters of P transgenes (P-lac-w) display a variegating phenotype for the w marker. In addition, X-ray-induced rearrangements of chromosomes bearing such clusters may lead to enhancement of the variegated phenotype. Since P-lacZ transgenes in subtelomeric heterochromatin have some P-element repression abilities, we tested whether P-lac-w clusters also have the capacity to repress P-element activity in the germline. One cluster (T-1), located on a rearranged chromosome (T2;3) and derived from a line bearing a variegating tandem array of seven P-lac-w elements, partially represses the dysgenic sterility (GD sterility) induced by P elements. This cluster also strongly represses in trans the expression of P-lacZ elements in the germline. This latter suppression shows a maternal effect. Finally, the combination of variegating P-lac-w clusters and a single P-lacZ reporter inserted in subtelomeric heterochromatic sequences at the X chromosome telomere (cytological site 1A) leads to strong repression of dysgenic sterility. These results show that repression of P-induced dysgenic sterility can be elicited in the absence of P elements encoding a polypeptide repressor and that a transgene cluster can repress the expression of a single homologous transgene at a nonallelic position. Implications for models of transposable element silencing are discussed.

Ronsseray, S; Boivin, A; Anxolabehere, D

2001-01-01

162

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

Harstad, J. Bruce

1965-01-01

163

Transgenic barley plants overexpressing a 13-lipoxygenase to modify oxylipin signature.  

PubMed

Three chimeric gene constructs were designed comprising the full length cDNA of a lipoxygenase (LOX) from barley (LOX2:Hv:1) including its chloroplast targeting sequence (cTP) under control of either (1) CaMV35S- or (2) polyubiquitin-1-promoter, whereas the third plasmid contains 35S promoter and the cDNA without cTP. Transgenic barley plants overexpressing LOX2:Hv:1 were generated by biolistics of scutella from immature embryos. Transformation frequency for 35S::LOX with or without cTP was in a range known for barley particle bombardment, whereas for Ubi::cTP-LOX no transgenic plants were detected. In general, a high number of green plantlets selected on bialaphos became yellow and finally died either in vitro or after potting. All transgenic plants obtained were phenotypically indistinguishable from wild type plants and all of them set seeds. The corresponding protein (LOX-100) in transgenic T0 and T1 plants accumulated constitutively to similar levels as in the jasmonic acid methyl ester (JAME)-treated wild type plants. Moreover, LOX-100 was clearly detectable immunocytochemically within the chloroplasts of untreated T0 plants containing the LOX-100-cDNA with the chloroplast target sequence. In contrast, an exclusive localization of LOX-100 in the cytoplasm was detectable when the target sequence was removed. In comparison to sorbitol-treated wild type leaves, analysis of oxylipin profiles in T2 progenies showed higher levels of jasmonic acid (JA) for those lines that displayed elevated levels of LOX-100 in the chloroplasts and for those lines that harboured LOX-100 in the cytoplasm, respectively. The studies demonstrate for the first time the constitutive overexpression of a cDNA coding for a 13-LOX in a monocotyledonous species and indicate a link between the occurrence of LOX-100 and senescence. PMID:16376956

Sharma, Vijendra K; Monostori, Tamas; Göbel, Cornelia; Hänsch, Robert; Bittner, Florian; Wasternack, Claus; Feussner, Ivo; Mendel, Ralf R; Hause, Bettina; Schulze, Jutta

2005-12-27

164

Controlling transgene expression in subcutaneous implants using a skin lotion containing the apple metabolite phloretin  

PubMed Central

Adjustable control of therapeutic transgenes in engineered cell implants after transdermal and topical delivery of nontoxic trigger molecules would increase convenience, patient compliance, and elimination of hepatic first-pass effect in future therapies. Pseudomonas putida DOT-T1E has evolved the flavonoid-triggered TtgR operon, which controls expression of a multisubstrate-specific efflux pump (TtgABC) to resist plant-derived defense metabolites in its rhizosphere habitat. Taking advantage of the TtgR operon, we have engineered a hybrid P. putida–mammalian genetic unit responsive to phloretin. This flavonoid is contained in apples, and, as such, or as dietary supplement, regularly consumed by humans. The engineered mammalian phloretin-adjustable control element (PEACE) enabled adjustable and reversible transgene expression in different mammalian cell lines and primary cells. Due to the short half-life of phloretin in culture, PEACE could also be used to program expression of difficult-to-produce protein therapeutics during standard bioreactor operation. When formulated in skin lotions and applied to the skin of mice harboring transgenic cell implants, phloretin was able to fine-tune target genes and adjust heterologous protein levels in the bloodstream of treated mice. PEACE-controlled target gene expression could foster advances in biopharmaceutical manufacturing as well as gene- and cell-based therapies.

Gitzinger, Marc; Kemmer, Christian; El-Baba, Marie Daoud; Weber, Wilfried; Fussenegger, Martin

2009-01-01

165

Assessment of inheritance pattern and agronomic performance of transgenic rapeseed having harpin Xooc-encoding hrf2 gene.  

PubMed

hrf2 gene is a member of the harpin-encoding gene family of rice-pathogenic bacterium Xanthomonas oryzae pv. oryzicola. In our previous studies, we observed that harpin(Xooc) could elicit hypersensitive cell death in non-host plants, induce disease and insect resistance in plants, and enhance plant growth. In this study, the rapeseed cultivar, Yangyou 4, was genetically engineered via Agrobacterium-mediated transformation to express the hrf2 gene. Polymerase chain reaction (PCR) and southern blot analyses of T(1) generation of transgenic rapeseed revealed stable integration and expression of the inserted gene hrf2. In addition, the resistance to Sclerotinia sclerotiorum was greatly enhanced. A comparison between agronomic characters of transgenic and control lines displayed significant differences in terms of plant height, stem width, number of pods per plant, number of seeds per pod, 1,000-seed weight, and seed yield per plant. Among lines with resistance to S. sclerotiorum, T(1)1 had improved agronomic traits compared with controls with a 22.7% seed yield increase. These results suggest that the introduction of the hrf2 gene into rapeseed can be an effective strategy for enhancing resistance to S. sclerotiorum. PMID:20107894

Huo, Rong; Wang, Yu; Ma, Ling-Li; Qiao, Jun-Qing; Shao, Min; Gao, Xue-Wen

2010-01-27

166

[Obtaining marker-free transgenic soybean plants with optimal frequency by constructing three T-DNAs binary vector].  

PubMed

Obtaining marker-free plants with high efficiency will benefit the environmental release of transgenic crops. To achieve this point, a binary vector pNB35SVIP1 with three T-DNAs was constructed by using several mediate plasmids, in which one copy of bar gene expression cassette and two copies of VIP1 gene expression cassette were included. EHA101 Agrobacterium strain harboring the final construct was applied to transform soybean (Glycine max) cotyledon nodes. Through 2 - 3 months regeneration and selection on 3 - 5mg/L glufosinate containing medium, transgenic soybean plants were confirmed to be obtained at 0.83% - 3.16%, and co-transformation efficiency of both gene in the same individual reached up to 86.4%, based on southern blot test. By the analysis of PCR, southern blot and northern blot combining with leaf painting of herbicide in T1 progenies, 41 plants were confirmed to be eliminated of bar gene with the frequency of 7.6% . Among the T1 populations tested, the loss of the alien genes happened in 22.7% lines, the silence of bar gene took place in 27.3% lines, and VIP1 gene silence existed in 37.1% marker-free plants. The result also suggested that the plasmid with three T-DNAs might be an ideal vector to generate maker-free genetic modified organism. PMID:17366903

Ye, Xing-Guo; Qin, Hua

2007-01-01

167

Type I callus as a bombardment target for generating fertile transgenic maize ( Zea mays L.)  

Microsoft Academic Search

To develop a less genotype-dependent maize-transformation procedure, we used 10-month-old Type I callus as target tissue for microprojectile bombardment. Twelve transgenic callus lines were obtained from two of the three anther-culture-derived callus cultures representing different gentic backgrounds. Multiple fertile transgenic plants (T0) were regenerated from each transgenic callus line. Transgenic leaves treated with the herbicide Basta showed no symptoms, indicating

Yuechun Wan; Jack M. Widholm; Peggy G. Lemaux

1995-01-01

168

Increased Expression of P-Glycoprotein Is Associated with Doxorubicin Chemoresistance in the Metastatic 4T1 Breast Cancer Model  

PubMed Central

Development of drug resistance is one of the major causes of breast cancer treatment failure. The goal of this study was to understand the chemoresistance mechanism using the highly metastatic 4T1 breast cancer model, which emulates stage IV breast cancer in humans. The metastatic 4T1 breast cancer cell line treated with either doxorubicin or 5-FU showed a concentration-dependent reduced cell proliferation, with induced G2-phase growth arrest (doxorubicin) or G1-phase growth arrest (5-FU). Doxorubicin treatment partially suppressed the multiorgan metastasis of 4T1 breast cancer cells in the lung, heart, liver, and bone, compared with either 5-FU or cyclophosphamide. We isolated and characterized 4T1 breast cancer cells from doxorubicin-resistant metastatic tumors (cell line 4T1-R). Multiorgan metastasis of drug-resistant 4T1 breast tumors was totally resistant to doxorubicin treatment. Our results indicate that doxorubicin is localized exclusively in the cytoplasm of resistant 4T1 breast cancer cells and that it cannot reach the nucleus because of increased nuclear expression of P-glycoprotein. Pretreatment of doxorubicin-resistant 4T1-R breast cancer cells with verapamil, a general inhibitor of P-glycoprotein, increased nuclear translocation of doxorubicin and cellular cytotoxicity. Thus, impaired nuclear translocation of doxorubicin due to increased expression of P-glycoprotein is associated with doxorubicin resistance of highly metastatic 4T1 breast cancer.

Bao, Lili; Haque, Aliyya; Jackson, Kamilah; Hazari, Sidhartha; Moroz, Krzysztof; Jetly, Rachna; Dash, Srikanta

2011-01-01

169

T1? MRI Quantification of Arthroscopically-Confirmed Cartilage Degeneration  

PubMed Central

9 asymptomatic subjects and 6 patients underwent T1? MRI to determine whether Outerbridge grade 1 or 2 cartilage degeneration observed during arthroscopy could be detected noninvasively. MRI was performed 2–3 months post-arthroscopy using sagittal T1-weighted and axial and coronal T1? MRI from which spatial T1? relaxation maps were calculated from segmented T1-weighted images. Median T1? relaxation times of patients with arthroscopically documented cartilage degeneration and asymptomatic subjects were significantly different (p < 0.001) and median T1? exceeded asymptomatic articular cartilage median T1? by 2.5 to 9.2 ms. In 8 observations of mild cartilage degeneration at arthroscopy (Outerbridge grades 1 and 2), mean compartment T1? was elevated in 5, but in all observations, large foci of increased T1? were observed. It was determined that T1? could detect some, but not all, Outerbridge grade 1 and 2 cartilage degeneration but that a larger patient population is needed to determine the sensitivity to these changes.

Witschey, Walter RT; Borthakur, Arijitt; Fenty, Matt; Kneeland, J Bruce; Lonner, Jess H; McArdle, Erin L.; Sochor, Matt; Reddy, Ravinder

2010-01-01

170

Strategies for engineering virus resistance in transgenic plants  

Microsoft Academic Search

Summary  Transgenic virus-resistant plants were first produced in 1986 by genetically engineering tobacco plants to express the coat\\u000a protein of tobacco mosaic virus. The introduction of coat protein transgenes has since proved to be an extremely effective\\u000a and generally applicable approach to engineering virus resistance in crop plants. Extensive field trials with transgenic,\\u000a virus-resistant tobacco, tomato, potato and cucumber lines have

T. A. Kavanagh; C. Spillane

1995-01-01

171

Studies of an expanded trinucleotide repeat in transgenic mice  

SciTech Connect

Spinal and bulbar muscular atrophy (SBMA) is a progressive motor neuron disease caused by expansion of a trinucleotide repeat in the androgen receptor gene (AR{sup exp}). AR{sup exp} repeats expand further or contract in approximately 25% of transmissions. Analogous {open_quotes}dynamic mutations{close_quotes} have been reported in other expanded trinucleotide repeat disorders. We have been developing a mouse model of this disease using a transgenic approach. Expression of the SBMA AR was documented in transgenic mice with an inducible promoter. No phenotypic effects of transgene expression were observed. We have extended our previous results on stability of the expanded trinucleotide repeat in transgenic mice in two lines carrying AR{sup exp}. Tail DNA was amplified by PCR using primers spanning the repeat on 60 AR{sup exp} transgenic mice from four different transgenic lines. Migration of the PCR product through an acrylamide gel showed no change of the 45 CAG repeat length in any progeny. Similarly, PCR products from 23 normal repeat transgenics showed no change from the repeat length of the original construct. Unlike the disease allele in humans, the expanded repeat AR cDNA in transgenic mice showed no change in repeat length with transmission. The relative stability of CAG repeats seen in the transgenic mice may indicate either differences in the fidelity of replicative enzymes, or differences in error identification and repair between mice and humans. Integration site or structural properties of the transgene itself might also play a role.

Bingham, P.; Wang, S.; Merry, D. [Univ. of Pennsylvania, Philadelphia, PA (United States)

1994-09-01

172

Wheat storage proteins in transgenic rice endosperm.  

PubMed

Transgenic rice seed expressing wheat HMW glutenin subunit was characterized to study the effects of the wheat prolamin on the protein expression pattern and protein size distribution in the endosperm and the functional and rheological properties of the rice flour and dough. Significant differences were found in the protein expression pattern between the transgenic and wild type samples. Comparing the protein expression profiles of transgenic and nontransgenic plants, combined with proteomic-based studies, indicated increased protein disulfide isomerase (PDI) levels in the transgenic rice lines. The accurate molecular size of HMW-GS in rice endosperm was identified by MALDI-TOF-MS analysis. The expressed wheat HMW (subunit 1Dx5) GS showed a positive effect on the functional properties of rice dough by significantly increasing the size distribution of the polymeric protein fraction and modifying the dough mixing parameters. PMID:23802557

Oszvald, Mária; Balázs, Gábor; Pólya, Sára; Tömösközi, Sándor; Appels, Rudi; Békés, Ferenc; Tamás, László

2013-07-25

173

Transcriptional changes related to secondary wall formation in xylem of transgenic lines of tobacco altered for lignin or xylan content which show improved saccharification  

PubMed Central

In this study, an EST library (EH663598–EH666265) obtained from xylogenic tissue cultures of tobacco that had been previously generated was annotated. The library proved to be enriched in transcripts related to the synthesis and modification of secondary cell walls. The xylem-specific transcripts for most of the genes of the lignification and xylan pathways were identified and several full-length sequences obtained. Gene expression was determined in available tobacco lines down-regulated for enzymes of the phenylpropanoid pathway: CINNAMATE 4-HYDROXYLASE (sc4h), CINNAMOYL-COA REDUCTASE (asccr) and lignification-specific peroxidase (asprx). In addition, lines down-regulated in the nucleotide-sugar pathway to xylan formation through antisense expression of UDP-GLUCURONIC ACID DECARBOXYLASE (asuxs) were also analysed. It is shown herein that most transcripts were down-regulated for both lignin and xylan synthesis pathways in these lines, while CELLULOSE SYNTHASE A3 was up-regulated in lignin-modified lines. The analysis indicates the existence of interdependence between lignin and xylan pathways at the transcriptional level and also shows that levels of cellulose, xylan and lignin are not necessarily directly correlated to differences in transcription of the genes involved upstream, as shown by cell wall fractionation and sugar analysis. It is therefore suggested that cell wall biosynthesis regulation occurs at different levels, and not merely at the transcriptional level. In addition, all lines analyzed showed improved enzymic saccharification of secondary but not primary walls. Nevertheless, this demonstrates potential industrial applicability for the approach undertaken to improve biomass utility.

Cook, Charis M.; Daudi, Arsalan; Millar, David J.; Bindschedler, Laurence V.; Khan, Safina; Bolwell, G. Paul; Devoto, Alessandra

2012-01-01

174

Transgenic overexpression of connexin50 induces cataracts  

PubMed Central

To examine the effects of increased expression of Cx50 in the mouse lens, transgenic mice were generated using a DNA construct containing the human Cx50 coding region and a C-terminal FLAG epitope driven by the chicken ?B1-crystallin promoter. Expression of this protein in paired Xenopus oocytes induced gap junctional currents of similar magnitude to wild type human Cx50. Three lines of transgenic mice expressing the transgenic protein were analyzed. Lenses from transgenic mice were smaller than those from non-transgenic littermates, and had cataracts that were already visible at postnatal day 1. Expression of the transgene resulted in a 3- to 13-fold increase in Cx50 protein levels above those of non-transgenic animals. Light microscopy revealed alterations in epithelial cell differentiation, fiber cell structure, interactions between fiber cells and areas of liquefaction. Scanning electron microscopy showed fiber cells of varying widths with bulging areas along single fibers. Anti-Cx50 and anti-FLAG immunoreactivities were detected at appositional membranes and in intracellular vesicles in transgenic lenses. N-cadherin, Cx46, ZO-1 and aquaporin 0 localized mainly at the plasma membrane, although some N-cadherin and aquaporin 0 was associated with the intracellular vesicles. The abundance and solubility/integrity of ?A-, ?B-, ?- and ?-crystallin were unaffected. These results demonstrate that transgenic expression of Cx50 in mice leads to cataracts associated with formation of cytoplasmic vesicles containing Cx50 and decreased or slowed epithelial differentiation without major alterations in the distribution of other integral membrane or membrane-associated proteins or the integrity/solubility of crystallins.

Chung, June; Berthoud, Viviana M.; Novak, Layne; Zoltoski, Rebecca; Heilbrunn, Benjamin; Minogue, Peter J.; Liu, Xiaoqin; Ebihara, Lisa; Kuszak, Jer; Beyer, Eric C.

2007-01-01

175

Regulatory and policy issues for T1DM immunotherapy.  

PubMed

The development of immunotherapies for T1DM has lagged the development T2DM drugs, but with more clarity around regulatory requirements, large pharmaceutical companies have recently entered the field to support late stage programs. This clarity around regulatory expectations has emerged because of the convergence among regulators and clinical experts in how efficacy of these therapies should be assessed. The key agreement is that the primary efficacy endpoint for treatments directed at the underlying autoimmune cause of T1DM should be endogenous insulin secretion as reflected by standardized C-peptide measurements. Important secondary endpoints include glycemic control, total daily insulin dose, and hypoglycemia rates. Most T1DM therapeutic development efforts are directed at new onset disease, which represents a small proportion of the entire T1DM population. A new frontier in T1DM therapeutic development is emerging around combination treatment of established T1DM, a population that far outnumbers those with new onset T1DM. Fully effective therapies of new onset or established T1DM will almost certainly require a combination of two or more therapies. A T1DM prevention vaccine will not be feasible until after extensive experience with the agent as a treatment of new onset and/or established T1DM. PMID:21242726

Fleming, Alexander

2011-01-01

176

Caecal fermentation in rats fed diets containing transgenic potato tubers  

Microsoft Academic Search

Caecal fermentation in rats fed diets with 40% autoclaved potato tubers was examined. The potato tubers of the conventional cultivar, Irga, somaclone Irga, and four transgenic lines with genetically improved resistance to a necrotic strain of potato virus Y (PVY N ) were compared. As regards the analysed indices, tubers of transgenic clone R1F (truncated gene coding PVY N

J. Ju?kiewicz; Z. Zdu?czyk; S. Frejnagel; J. Fornal

177

Human Tissue Kallikrein Induces Hypotension in Transgenic Mice  

Microsoft Academic Search

We investigated the role of the kallikrein-kinin system in blood pressure control by developing transgenic mice overexpressing human tissue kallikrein. Two lines of trans- genic mice carrying the human tissue kallikrein gene under the control of the mouse metallothionein metal-responsive pro- moter were established. Human tissue kallikrein was identified in pancreas, salivary gland, kidney, liver, and spleen of the transgenic

Jing Wang; William Xiong; Zhirong Yang; Tia Davis; Michael J. Dewey; Julie Chao; Lee Chao

2009-01-01

178

Hepatic steatosis in transgenic mice overexpressing human histone deacetylase 1  

SciTech Connect

It is generally thought that histone deacetylases (HDACs) play important roles in the transcriptional regulation of genes. However, little information is available concerning the specific functions of individual HDACs in disease states. In this study, two transgenic mice lines were established which harbored the human HDAC1 gene. Overexpressed HDAC1 was detected in the nuclei of transgenic liver cells, and HDAC1 enzymatic activity was significantly higher in the transgenic mice than in control littermates. The HDAC1 transgenic mice exhibited a high incidence of hepatic steatosis and nuclear pleomorphism. Molecular studies showed that HDAC1 may contribute to nuclear pleomorphism through the p53/p21 signaling pathway.

Wang, Ai-Guo [Laboratory of Human Genomics, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806 (Korea, Republic of); Seo, Sang-Beom [Department of Life Science, College of Natural Sciences, Chung-Ang University, Seoul 156-756 (Korea, Republic of); Moon, Hyung-Bae [Department of Pathology, School of Medicine, Institute of Medical Science, Wonkwang University, Iksan, Jeonbuk 570-749 (Korea, Republic of); Shin, Hye-Jun [Laboratory of Human Genomics, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806 (Korea, Republic of); Kim, Dong Hoon [Department of Oral Biochemistry, College of Dentistry, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Kim, Jin-Man [Department of Bioscience and Biotechnology, Institute of Bioscience, Sejong University, 98 Kunja-dong, Kwangjin-gu, Seoul 143-747 (Korea, Republic of); Lee, Tae-Hoon [Department of Pathology, College of Medicine, Chungnam National University, Daejeon 301-131 (Korea, Republic of); Kwon, Ho Jeong [Department of Oral Biochemistry, College of Dentistry, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Yu, Dae-Yeul [Laboratory of Human Genomics, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806 (Korea, Republic of)]. E-mail: dyyu10@kribb.re.kr; Lee, Dong-Seok [Laboratory of Human Genomics, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806 (Korea, Republic of)]. E-mail: lee10@kribb.re.kr

2005-05-06

179

T1R receptors mediate mammalian sweet and umami taste.  

PubMed

The T1R family of taste receptors mediates 2 taste qualities: T1R2/T1R3 for sweet taste and T1R1/T1R3 for umami taste. Functional expression in heterologous system and gene knockout studies has shown their functions as taste receptors. Structure-function relation studies on T1R2/T1R3 showed multiple ligand binding sites on both subunits. The umami taste of l-glutamate can be drastically enhanced by 5' ribonucleotides, and the synergy is a hallmark of this taste quality. On the basis of chimeric T1R receptors, site-directed mutagenesis, and molecular modeling data, we recently proposed a cooperative ligand binding model that involved the Venus flytrap domain of T1R1 in which l-glutamate binds close to the hinge region and 5' ribonucleotides bind to an adjacent site close to the opening of the flytrap to further stabilize the closed conformation. This novel mechanism may apply to other class C, G protein-coupled receptors. PMID:19656838

Li, Xiaodong

2009-08-05

180

Marker-free transgenic (MFT) near-isogenic introgression lines (NIILs) of 'golden' indica rice (cv. IR64) with accumulation of provitamin A in the endosperm tissue.  

PubMed

We have developed near-isogenic introgression lines (NIILs) of an elite indica rice cultivar (IR64) with the genes for beta-carotene biosynthesis from dihaploid (DH) derivatives of golden japonica rice (cv. T309). A careful analysis of the DH lines indicated the integration of the genes of interest [phytoene synthase (psy) and phytoene desaturase (crtI)] and the selectable marker gene (hygromycin phosphotransferase, hph) in two unlinked loci. During subsequent crossing, progenies could be obtained carrying only the locus with psy and crtI, which was segregated independently from the locus containing the hph gene during meiotic segregation. The NIILs (BC(2)F(2)) showed maximum similarity with the recurrent parent cultivar IR64. Further, progenies of two NIILs were devoid of any fragments beyond the left or right border, including the chloramphenicol acetyltransferase (cat) antibiotic resistance gene of the transformation vector. Spectrophotometric readings showed the accumulation of up to 1.06 microg total carotenoids, including beta-carotene, in 1 g of the endosperm. The accumulation of beta-carotene was also evident from the clearly visible yellow colour of the polished seeds. PMID:17177811

Baisakh, Niranjan; Rehana, Sayda; Rai, Mayank; Oliva, Norman; Tan, Jing; Mackill, David J; Khush, Gurdev S; Datta, Karabi; Datta, Swapan K

2006-07-01

181

Black carp growth hormone gene transgenic allotetraploid hybrids of Carassius auratus red var. (?)×Cyprinus carpio (?).  

PubMed

Ecological safety is a major consideration in the commercialization of transgenic fish. Development of sterile transgenic triploid fish through hybridization of transgenic tetraploid fish and transgenic diploid fish is a feasible way to solve this problem. The "all-fish" transgene, pbcAbcGHc, containing the black carp ?-actin gene promoter and the open reading frame (ORF) of the black carp growth hormone (GH) gene was constructed and introduced into fertilized eggs of allotetraploid fish through microinjection. Contrast cultivation results showed that the growth rate of 150 day-old P(0) black carp GH gene transgenic allotetraploid fish was much higher than that of controls. Sixty 150 day-old transgenic allotetraploid fish were assayed by PCR for transgene integration and 90% of fish were positive for the transgene. The transgene was detected in 13 of 20 sperm samples from male transgenic allotetraploid fish. RT-PCR detected transcription of the exogenous black carp GH gene in the muscle, liver, kidney and ovaries of the largest transgenic allotetraploid fish. This study has developed P(0) black carp GH gene transgenic allotetraploid fish with a highly increased growth rate, which provides a solid foundation for the establishment of a pure line of transgenic allotetraploid fish and for the large scale production of sterile transgenic triploid fish. PMID:21809038

Feng, Hao; Fu, Yongming; Luo, Jian; Wu, Hui; Liu, Yun; Liu, Shaojun

2011-08-01

182

Complete sequence analysis of transgene loci from plants transformed via microprojectile bombardment  

Microsoft Academic Search

A substantial literature exists characterizing transgene locus structure from plants transformed via Agrobacterium and direct DNA delivery. However, there is little comprehensive sequence analysis of transgene loci available, especially from plants transformed by direct delivery methods. The goal of this study was to completely sequence transgene loci from two oat lines transformed via microprojectile bombardment that were shown to have

I. Makarevitch; S. K. Svitashev; D. A. Somers

2003-01-01

183

Regulation of CAT protein by ribozyme and antisense mRNA in transgenic mice  

Microsoft Academic Search

Transgenic mouse lines were engineered to express stably antisense mRNA or antisense mRNA containing catalytic ribozyme (rbz) structures complementary to bacterial chloramphenicol acetyltransferase (CAT) gene transcripts. One transgenic line expressed antisense mRNA that specifically targeted full-length CAT coding sequences (ACAT). Another transgenic line expressed full-length antisense CAT mRNA which was modified by mutagensis to include four rbz cassettes (rbz-ACAT) in

Deborah L. Sokol; Robert J. Passey; Anthony G. Mackinlay; James D. Murray

1998-01-01

184

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.

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

2009-01-01

185

TRANSGENIC COMPARISONS OF PINK BOLLWORM EFFICACY AND RESPONSE TO HEAT STRESS.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Fifteen lines from 3 different cotton families were compared. Each family had a conventional, non-transgenic standard, as well as 4 other transgenic lines. Each Bt line was evaluated for this trait's efficacy in controlling pink bollworm under high pressure, artificial infestations. Various agronomi...

186

Repressible transgenic model of NRAS oncogene-driven mast cell disease in the mouse  

Microsoft Academic Search

To create a model in which to study the effects of RAS dysregulation in hemato- poietic disease, we developed separate founder lines of transgenic mice, with the tetracycline transactivator (tTA) driven by the Vav hematopoietic promoter in one line and NRASV12 driven by the tetracy- cline responsive element (TRE2) in the other. When these lines are crossed, dou- bly transgenic

Stephen M. Wiesner; Jamie M. Jones; Diane E. Hasz; David A. Largaespada

2005-01-01

187

T1 intralaminar screws: an anatomic, morphologic study.  

PubMed

In some scenarios, such as complex revisions or tumor cases, intralaminar screw placement in the upper thoracic spine can be used to supplement or replace traditional pedicle screw placement. Despite the theortic feasibility of placing these screws, no thorough anatomic study has evaluated the morphology of the T1 lamina for screw placement.Anatomic data of the T1 lamina, including height, width (the upper, middle, and lower one-third segments), and length (with and without penetration of the facet articulation) were analyzed for 112 T1 vertebrae. The placement of screws with widths of 3.5 or 4 mm and screws with lengths of 24 or 26 mm in the T1 lamina was feasible in all of the laminas measured with the exception of 2 outliers. Furthermore, relationships were found between T1 lamina size and patient height and between T1 lamina size and sex, but no relationship was found between T1 lamina size and race.The morphology of the T1 lamina allows for the simple and safe placement of common screw diameters and is a viable salvage or alternative to the traditional pedicle screw. PMID:23590788

Weaver, John; Seipel, Shane; Eubanks, Jason

2013-04-01

188

The effects of transformation and ZnT-1 silencing on zinc homeostasis in cultured cells.  

PubMed

We have previously demonstrated that reducing the availability of zinc with the extracellular chelator diethylenetriaminepentaacetic acid (DTPA) promotes efflux of (65)Zn from rat primary hepatocytes and pituitary cells, but increases retention of label in rat hepatoma (H4IIE) and anterior pituitary tumor (GH3) cell lines. To further understand this differential response between primary cells and the corresponding cancer cell lines, we investigated the effects of immortalizing primary cells on their zinc homeostasis. Rat primary hepatocytes were electroporated with the SV40 large T-antigen-coding plasmid pSV3-neo and selected for neomycin resistance. This resulted in cell division of the normally quiescent hepatocytes. When these cells were prelabeled with (65)Zn, DTPA decreased efflux of (65)Zn, similarly to hepatoma cells and differently from primary hepatocytes. This homeostatic change may be required to account for the greater zinc requirements of dividing cells and be mediated by alterations in the activity of zinc transporter ZnT-1, which is responsible for zinc efflux. To further understand the mechanism of DTPA-induced zinc retention, we down-regulated the expression of ZnT-1 in rat hepatoma cells using vector-based short hairpin RNA interference. Expression of ZnT-1 protein was reduced to approximately 50%. Down-regulation of ZnT-1 resulted in greater retention of (65)Zn in control cells. However, DTPA increased rather than decreased efflux of label from knockdown cells, suggesting that functional ZnT-1 is required for the decreased efflux in response to DTPA. We conclude that ZnT-1 expression is crucial for maintaining zinc homeostasis, in particular, for the enhanced retention of zinc in transformed cells when subjected to zinc deprivation. PMID:21775119

Sankavaram, Kavitha; Freake, Hedley C

2011-07-19

189

Variation in GUS activity in vegetatively propagated Hevea brasiliensis transgenic plants  

Microsoft Academic Search

Hevea brasiliensis transgenic plants are regenerated from transgenic callus lines by somatic embryogenesis. Somatic embryogenesis is not yet\\u000a available for commercial propagation of Hevea clones, which requires conventional grafting of buds on rootstock seedlings (budding). The stability of transgene expression\\u000a in budded plants is therefore necessary for further development of genetic engineering in rubber trees. Transgene expression\\u000a was assessed by

Ludovic Lardet; Julie Leclercq; Elise Bénistan; Florence Dessailly; Gérald Oliver; Florence Martin; Pascal Montoro

190

TRANSGENIC COTTON (GOSSYPIUM HIRSUTUM L.) SEEDLINGS EXPRESSING A TOBACCO GLUTATHIONE S-TRANSFERASE FAIL TO PROVIDE IMPROVED STRESS TOLERANCE  

Technology Transfer Automated Retrieval System (TEKTRAN)

Transgenic cotton (Gossypium hirsutum L.) lines expressing the tobacco glutahione S-transferase (GST) Nt107 were evaluated for tolerance to chilling, salinity, and herbicides, antioxidant enzyme activity, antioxidant compound levels, and lipid peroxidation. Although transgenic seedlings exhibited 1...

191

Field evaluation and risk assessment of transgenic indica basmati rice  

Microsoft Academic Search

We report the first field trial of different transgenic lines of Indica Basmati rice (B-370) expressing cry1Ac and cry2A genes. Different transgenic lines were grown under field conditions for two consecutive years, according to RCBD and Split Plot Design respectively. All the biosafety measures were taken into consideration. Sixty neonate larvae of yellow stem borer were artificially infested into each

Khurram Bashir; Tayyab Husnain; Tahira Fatima; Zakia Latif; Syed Aks Mehdi; Sheikh Riazuddin

2004-01-01

192

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

193

Mycorrhizal colonization of transgenic aspen in a field trial.  

PubMed

Mycorrhizal colonization of genetically modified hybrid aspen (Populus tremula x P. tremuloides Michx.) was investigated over 15 months in a field experiment. The aspen carried the rolC gene from Agrobacterium rhizogenes under control of either the constitutive cauliflower mosaic virus 35S promoter or the light-inducible rbcS promoter. Arbuscular mycorrhizas (AMs) were rare in all root samples, while fully developed ectomycorrhizas (EMs) were found in all samples. No significant differences in the degree of mycorrhizal colonization between aspen lines were seen with either AMs or EMs. The EM community on the release area was dominated by four fungal species that formed more than 90% of all mycorrhizas, while eleven EM types were found occasionally. Mycorrhizal diversity did not differ between transgenic and non-transgenic trees. The structure of mycorrhizal communities was similar for most aspen lines. The sole significant difference was found in the abundance and development of one of the four common EM morphotypes, which was rare and poorly developed on roots from the transgenic aspen line Esch5:35S-rolC-#5 compared with non-transgenic controls. This effect is clone specific as the formation of this EM type was not affected by the transgene expression in the other transgenic line, Esch5:35S-rolC-#1. This is the first demonstration of a clonal effect influencing the ability of a transgenic plant to form a mycorrhizal symbiosis with a potential fungal partner. PMID:11925050

Kaldorf, Michael; Fladung, Matthias; Muhs, Hans J; Buscot, François

2002-02-01

194

Breaking-off tissue specific activity of the oil palm metallothionein-like gene promoter in T(1) seedlings of tomato exposed to metal ions.  

PubMed

Metallothioneins (MTs) are cysteine-rich metal-binding proteins that are involved in cell growth regulation, transportation of metal ions and detoxification of heavy metals. A mesocarp-specific metallothionein-like gene (MT3-A) promoter was isolated from the oil palm (Elaeis guineensis Jacq). A vector construct containing the MT3-A promoter fused to the ?-glucuronidase (GUS) gene in the pCAMBIA 1304 vector was produced and used in Agrobacterium-mediated transformation of tomato. Histochemical GUS assay of different tissues of transgenic tomato showed that the MT3-A promoter only drove GUS expression in the reproductive tissues and organs, including the anther, fruit and seed coat. Competitive RT-PCR and GUS fluorometric assay showed changes in the level of GUS mRNA and enzyme activity in the transgenic tomato (T(0)). No GUS mRNA was found in roots and leaves of transgenic tomato. In contrast, the leaves of transgenic tomato seedlings (T(1)) produced the highest GUS activity when treated with 150 ?M Cu(2+) compared to the control (without Cu(2+)). However, Zn(2+) and Fe(2+) treatments did not show GUS expression in the leaves of the transgenic tomato seedlings. Interestingly, the results showed a breaking-off tissue-specific activity of the oil palm MT3-A promoter in T(1) seedlings of tomato when subjected to Cu(2+) ions. PMID:23290536

Kamaladini, Hossein; Nor Akmar Abdullah, Siti; Aziz, Maheran Abdul; Ismail, Ismanizan Bin; Haddadi, Fatemeh

2013-01-03

195

Transgene silencing and transgene-derived siRNA production in tobacco plants homozygous for an introduced AtMYB90 construct  

Technology Transfer Automated Retrieval System (TEKTRAN)

Transgenic tobacco (Nicotiana tabacum) lines were engineered to ectopically over-express AtMYB90 (PAP2), an R2-R3 Myb gene associated with regulation of anthocyanin production in Arabidopsis thaliana. Independently transformed transgenic lines Myb27 and Myb237 accumulated large quantities of anthoc...

196

PET imaging of transgene expression  

Microsoft Academic Search

A vital step in transgenic animal study and gene therapy is the ability to assay the extent of transgene expression. Unfortunately, classic methods of assaying transgene expression require biopsies or death of the subject. We are developing techniques to noninvasively and repetitively determine the location, duration, and magnitude of transgene expression in living animals. This will allow investigators and clinicians

Duncan C. Maclaren; Tatsushi Toyokuni; Simon R. Cherry; Jorge R. Barrio; Michael E. Phelps; Harvey R. Herschman; Sanjiv S. Gambhir

2000-01-01

197

Production of fertile transgenic peanut (Arachis hypogaea L.) plants using Agrobacterium tumefaciens.  

PubMed

Fertile transgenic plants of peanut (Arachis hypogaea L. cv. New Mexico Valencia A) were produced using an Agrobacterium-mediated transformation system. Leaf section explants were inoculated with A. tumefaciens strain EHA105 harboring the binary vector pBI121 containing the genes for ?-glucuronidase (GUS) and neomycin phosphotransferase II (NPTII). Approximately 10% of the shoots regenerated on selection medium were GUS-positive. Five independent transformation events resulted in the production of 52 fertile transgenic peanut plants. On average, 240 d were required between seed germination for explant preparation and the production of mature t1 seed by T0 plants. Molecular analysis of transgenic plants confirmed the stable integration of the transgenes into the peanut genome. GUS expression segregated in a 3?1 Mendelian ratio in most T1 generation plants. PMID:24178604

Cheng, M; Jarret, R L; Li, Z; Xing, A; Demski, J W

1996-05-01

198

The New High Precision Optical Theodolite, T1.  

National Technical Information Service (NTIS)

This article describes the new Soviet T1 theodolite, which was developed by EOMZ, TsNIIGAiK (Electrotechnical, Optical and Mechanical Plant, Central Scientific Research Institute of Geodesy, Aerial Survey, and Cartography). Its production is to begin in 1...

D. A. Anikst

1968-01-01

199

Induction of melanoma in TPras transgenic mice.  

PubMed

In order to study the oncogenesis of melanocytes, transgenic mouse lines were established that express a mutated human Ha-ras (TPras) gene in pigment producing cells. The ras transgenic mice exhibit an altered phenotype, including melanocytic hyperplasia and a muted agouti coat, indicative of hyperproliferative melanocytes. These mice and their wild-type littermates have been subjected to a variety of carcinogenesis protocols, including 7, 12-dimethylbenz-[a]anthracene (DMBA), 12-O-tetradecanoylphorbol-13-acetate (TPA) and UV radiation exposure. Topical DMBA treatment of TPras mice resulted in a high incidence of melanomas. Metastatic lesions were observed in skin, lungs and lymph nodes. TPA treatment of TPras mice induced a small number of papillomas but no nevi or melanomas. UV light exposures induced papillomas in negative littermate and melanomas in some albino TPras mice. These results show that melanocytes expressing an activated Ha-ras in the TPras transgenic mice are susceptible to induction of melanoma by DMBA. PMID:10469620

Broome Powell, M; Gause, P R; Hyman, P; Gregus, J; Lluria-Prevatt, M; Nagle, R; Bowden, G T

1999-09-01

200

Irreversible change in the T1 temperature dependence with thermal dose using the proton resonance frequency-T1 technique.  

PubMed

Denaturation of macromolecules within the tissues is believed to be the major factor contributing to the damage of tissues upon hyperthermia. As a result, the value of the spin-lattice relaxation time T1 of the tissue water, which is related to the translational and rotational rates of water, represents an intrinsic probe for investigating structural changes in tissues at high temperature. Therefore, the goal of this work is to investigate whether the simultaneous measurement of temperature and T1 using a hybrid proton resonance frequency (PRF)-T1 measurement technique can be used to detect irreversible changes in T1 that might be indicative of tissue damage. A new hybrid PRF-T1 sequence was implemented based on the variable flip angle driven-equilibrium single-pulse observation (DESPOT)1 method from a standard three dimensional segmented echo-planar imaging sequence by alternating two flip angles from measurement to measurement. The structural changes of the heated tissue volumes were analyzed based on the derived T1 values and the corresponding PRF temperatures. Using the hybrid PRF-T1 technique, we demonstrate that the change of spin lattice relaxation time T1 is reversible with temperature for low thermal dose (thermal dose ? 240 cumulative equivalent minutes [CEM] 43°C) and irreversible with temperature after significant accumulation of thermal dose in ex vivo chicken breast tissue. These results suggest that the hybrid PRF-T1 method may be a potentially powerful tool to investigate the extent and mechanism of heat damage of biological tissues. PMID:22576265

Diakite, Mahamadou; Payne, Allison; Todd, Nick; Parker, Dennis L

2012-05-10

201

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).  

PubMed

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 nervous systems of such mice. The most affected structure was the spinal cord, followed by the medulla, pons and midbrain. The early stages of the disease were characterized by vascular degeneration of anterior horn neurons and their processes, while, in the late stages, the main changes consisted of neuronal loss and atrophy of the anterior horns and the deposition in these areas of multiple filamentous inclusions resembling Lewy bodies. In the late stages of the disease, the white matter of the spinal cord was also involved, particularly in the anterior and lateral columns. Posterior columns were also involved, but to a much lesser degree. The brainstem structures also showed vacuolar degeneration of several motor nuclei and of several groups neurons in the reticular formation. Anterior roots and peripheral nerves showed the classical features of Wallerian degeneration. The dorsal root ganglia, with rare exceptions, were unremarkable. The posterior roots showed mild changes in the most severely affected mice. Changes in these two affected lines were compared to changes in mice overexpressing wild type, rather than mutant human Cu,Zn SOD. These mice never developed clinical disease, although, pathologically, they developed very mild vacuolar changes in the anterior horns of the spinal cord and in motor axons. This study shows that although simple overexpression of SOD may be injurious to motor neurons, albeit very mildly, the mutant form is necessary to produce both clinical disease and severe pathological changes which, in the chronic stage of the disease, have striking similarities to human familial ALS. A dominant gain of function, therefore, is the most likely pathogenesis of tissue injury induced by mutations in Cu,Zn SOD. PMID:7796176

Dal Canto, M C; Gurney, M E

1995-04-01

202

hPepT1-mediated epithelial transport of bacteria-derived chemotactic peptides enhances neutrophil-epithelial interactions.  

PubMed Central

Intestinal epithelial cells express hPepT1, an apical transporter responsible for the uptake of a broad array of small peptides. As these could conceivably include n-formyl peptides, we examined whether hPepT1 could transport the model n-formylated peptide fMLP and, if so, whether such cellular uptake of fMLP influenced neutrophil-epithelial interactions. fMLP uptake into oocytes was enhanced by hPepT1 expression. In addition, fMLP competitively inhibited uptake of a known hPepT1 substrate (glycylsarcosine) in hPepT1 expressing oocytes. hPepT1 peptide uptake was further examined in a polarized human intestinal epithelial cell line (Caco2-BBE) known to express this transporter. Epithelial monolayers internalized apical fMLP in a fashion that was competitively inhibited by other hPepT1 recognized solutes, but not by related solutes that were not transported by hPepT1. Fluorescence analyses of intracellular pH revealed that fMLP uptake was accompanied by cytosolic acidification, consistent with the known function of hPepT1 as a peptide H+ cotransporter. Lumenal fMLP resulted in directed movement of neutrophils across epithelial monolayers. Solutes that inhibit hPepT1-mediated fMLP transport decreased neutrophil transmigration by approximately 50%. Conversely, conditions that enhanced the rate of hPepT1-mediated fMLP uptake (cytosolic acidification) enhanced neutrophil-transepithelial migration by approximately 70%. We conclude that hPepT1 transports fMLP and uptake of these peptide influences neutrophil-epithelial interactions. These data (a) emphasize the importance of hPepT1 in mediating intestinal inflammation, (b) raise the possibility that modulating hPepT1 activity could influence states of intestinal inflammation, and (c) provide the first evidence of a link between active transepithelial transport and neutrophil-epithelial interactions.

Merlin, D; Steel, A; Gewirtz, A T; Si-Tahar, M; Hediger, M A; Madara, J L

1998-01-01

203

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.

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

204

Resistance levels and fitness of protoporphyrinogen oxidase (PROTOX) inhibitor-resistant transgenic rice in paddy fields  

Microsoft Academic Search

We previously confirmed that the transgenic rice line, M4, was about 200-fold more resistant to oxyfluorfen than the wild-type (WT) rice in whole-plant bioassays in pots. The transgenic rice line was also cross-resistant to other protoporphyrinogen oxidase (PROTOX)-inhibiting herbicides, acifluorfen, carfentrazone, and oxadiazon. The objectives of this research were to (a) verify the resistance of transgenic rice plants to commercial

H. I. Jung; Y. I. Kuk; H. Y. Kim; K. Back; D. J. Lee; S. Lee; N. R. Burgos

2010-01-01

205

Identification of the cyclamate interaction site within the transmembrane domain of the human sweet taste receptor subunit T1R3.  

PubMed

The artificial sweetener cyclamate tastes sweet to humans, but not to mice. When expressed in vitro, the human sweet receptor (a heterodimer of two taste receptor subunits: hT1R2 + hT1R3) responds to cyclamate, but the mouse receptor (mT1R2 + mT1R3) does not. Using mixed-species pairings of human and mouse sweet receptor subunits, we determined that responsiveness to cyclamate requires the human form of T1R3. Using chimeras, we determined that it is the transmembrane domain of hT1R3 that is required for the sweet receptor to respond to cyclamate. Using directed mutagenesis, we identified several amino acid residues within the transmembrane domain of T1R3 that determine differential responsiveness to cyclamate of the human versus mouse sweet receptors. Alanine-scanning mutagenesis of residues predicted to line a transmembrane domain binding pocket in hT1R3 identified six residues specifically involved in responsiveness to cyclamate. Using molecular modeling, we docked cyclamate within the transmembrane domain of T1R3. Our model predicts substantial overlap in the hT1R3 binding pockets for the agonist cyclamate and the inverse agonist lactisole. The transmembrane domain of T1R3 is likely to play a critical role in the interconversion of the sweet receptor from the ground state to the active state. PMID:16076846

Jiang, Peihua; Cui, Meng; Zhao, Baohua; Snyder, Lenore A; Benard, Lumie M J; Osman, Roman; Max, Marianna; Margolskee, Robert F

2005-08-02

206

FIELD TRIAL OF TRANSGENIC INDIAN MUSTARD PLANTS SHOWS ENHANCED PHYTOREMEDIATION OF SELENIUM CONTAMINATED SEDIMENT  

Technology Transfer Automated Retrieval System (TEKTRAN)

Three transgenic Indian mustard (Brassica juncea) lines were tested under field conditions for their ability to remove selenium (Se) by extraction and volatilization from Se- and boron-contaminated saline sediment. The three transgenic lines overexpressed genes encoding the enzymes adenosine tripho...

207

Ripening Physiology of Fruit from Transgenic Tomato (Lycopersicon esculentum) Plants with Reduced Ethylene Synthesis  

Microsoft Academic Search

lhe physiological effects of reduced ethylene synthesis in a transgenic tomato (Lycopersicon esculentum) line expressing 1- aminocyclopropane-1-carboxylic acid (ACC) deaminase enzyme have been examined. Fruit from the transgenic line 5673 ripen significantly slower than control fruit when removed from the vine early in ripening. In contrast, fruit that remain attached to the plants ripen much more rapidly, exhibiting little delay

Harry J. Klee

208

Immortalized Kidney Cells Derived from Transgenic Mice Harboring L-Type Pyruvate Kinase and Vimentin Promoters  

Microsoft Academic Search

Targeted oncogenesis in transgenic mice, where an oncogene is placed under the control of the regulatory sequences of a cell-specific gene, has been used to derive several new types of differentiated nonepithelial and epithelial cell lines. This review summarizes the properties of cell lines derived from proximal, distal and collecting duct cells. The cells were obtained from kidneys of transgenic

A. Vandewalle

1999-01-01

209

[Construction of transgenic rice populations by inserting the maize transponson Ac/Ds and genetic analysis for several mutants].  

PubMed

An efficient and rapid gene transformation system of rice mediated by Agrobacterium tumefaciens was used. Calli induced from immature and mature embryos of Zhonghua No. 11, a japonic rice variety, were cultured with the A. tumefaciens strain EHA105 harboring the superbinary plasmid pDsBar1300 or pUBITs separately, and more than 400 independent transgenic lines inserted Ds element or Ac fragment were obtained. Some visible mutants in T0 or T1 generation were found, consisting of disease resistance, albino, dwarf, male sterile, chlorosis, early heading, late heading, stripe, etc. From the phenotype analysis, a few mutants such as dwarf and male sterile seemed to be linked to the Basta resistance and the transposon. PMID:11517602

Zhu, Z G; Xiao, H; Fu, Y P; Hu, G C; Yu, Y H; Si, H M; Zhang, J L; Sun, Z X

2001-05-01

210

Efficient transgenic rat production by a lentiviral vector.  

PubMed

A lentiviral construct for an enhanced green fluorescent protein (eGFP) driven by a chicken beta-actin promoter, cytomegalovirus enhancer, and intronic sequences from rabbit beta-globin (CAG) was used to produce transgenic lines of rats for evaluation of the usefulness of this approach in gene function studies. Fertilized eggs were collected from inbred Dahl S and outbred Sprague-Dawley rats, and approximately 100 pl of concentrated virus were microinjected into the perivitrelline space of one-cell embryos. Of 121 embryos injected, 60 pups (49.6%) were born. Transgenic rates averaged 22% in Dahl S and 14% in Sprague-Dawley rats. Copy number ranged from one to four in the founders, and the inheritance of the transgene in a subsequent F(1) population was 48.2%. The small number of insertion sites enabled us to derive inbred transgenic lines with a single copy of the transgene within one generation. Sequencing of each transgene insertion site revealed that they inserted as single copies with a preference for the introns of genes. The CAG promoter drove high levels of eGFP expression in brain, kidney, heart, and vasculature, making it very suitable for exploring the cardiovascular function of newly discovered genes. The pattern of eGFP expression was similar across five different F(1) transgenic lines, indicating that the expression of the transgene was independent of its chromosomal position. Thus lentiviral transgenesis provides a powerful tool for the production of transgenic inbred rats and will enhance the usefulness of this species in gene discovery and target validation studies. PMID:17322424

Michalkiewicz, Mieczyslaw; Michalkiewicz, Teresa; Geurts, Aron M; Roman, Richard J; Slocum, Glenn R; Singer, Oded; Weihrauch, Dorothee; Greene, Andrew S; Kaldunski, Mary; Verma, Inder M; Jacob, Howard J; Cowley, Allen W

2007-02-23

211

Multiacquisition t1-mapping MRI during tidal respiration for quantification of myocardial t1 in Swine with heart failure.  

PubMed

OBJECTIVE. The purpose of this article is to evaluate a free-breathing pulse sequence to quantify myocardial T1 changes in a swine model of tachycardia-induced heart failure. MATERIALS AND METHODS. Yorkshire swine were implanted with pacemakers and were ventricularly paced at 200 beats/min to induce heart failure. Animals were scanned twice with a 1.5-T MRI scanner, once at baseline and once at heart failure. A T1-mapping sequence was performed during tidal respiration before and 5 minutes after the administration of a gadolinium-chelate contrast agent. T1-mapping values were compared between the baseline and heart failure scans. The percentage of fibrosis of heart failure myocardial tissue was compared with similar left ventricular tissue from control animals using trichrome blue histologic analysis. RESULTS. In the study cohort, differences were found between the baseline and heart failure T1-mapping values before the administration of contrast agent (960 ± 96 and 726 ± 94 ms, respectively; p = 0.02) and after contrast agent administration (546 ± 180 and 300 ± 171 ms, respectively; p = 0.005). The animals with heart failure also had a difference histologically in the percentage of myocardial collagen compared with tissue from healthy control animals (control, 5.4% ± 1.0%; heart failure, 9.4% ± 1.6%; p < 0.001). CONCLUSION. The proposed T1-mapping technique can quantify diffuse myocardial changes associated with heart failure without the use of a contrast agent and without breath-holding. These T1 changes appear to be associated with increases in the percentage of myocardial collagen that in this study were not detected by traditional myocardial delayed enhancement imaging. T1 mapping may be a useful technique for detecting early but clinically significant myocardial fibrosis. PMID:24059393

Hood, Maureen N; Song, Ting; Bedocs, Peter; Capacchione, John F; Kasper, Christine E; Haigney, Mark C; Ho, Vincent B

2013-10-01

212

Recent advances in the development of new transgenic animal technology.  

PubMed

Transgenic animal technology is one of the fastest growing biotechnology areas. It is used to integrate exogenous genes into the animal genome by genetic engineering technology so that these genes can be inherited and expressed by offspring. The transgenic efficiency and precise control of gene expression are the key limiting factors in the production of transgenic animals. A variety of transgenic technologies are available. Each has its own advantages and disadvantages and needs further study because of unresolved technical and safety issues. Further studies will allow transgenic technology to explore gene function, animal genetic improvement, bioreactors, animal disease models, and organ transplantation. This article reviews the recently developed animal transgenic technologies, including the germ line stem cell-mediated method to improve efficiency, gene targeting to improve accuracy, RNA interference-mediated gene silencing technology, zinc-finger nuclease gene targeting technology and induced pluripotent stem cell technology. These new transgenic techniques can provide a better platform to develop transgenic animals for breeding new animal varieties and promote the development of medical sciences, livestock production, and other fields. PMID:22833168

Miao, Xiangyang

2012-07-26

213

Supersymmetric consistent truncations of IIB on T 1, 1  

NASA Astrophysics Data System (ADS)

We study consistent Kaluza-Klein reductions of type IIB supergravity on T 1,1 down to five-dimensions. We find that the most general reduction containing singlets under the global SU(2) × SU(2) symmetry of T 1,1 is mathcal{N} = 4 gauged supergravity coupled to three vector multiplets with a particular gauging due to topological and geometric flux. Key to this reduction is several modes which have not been considered before in the literature and our construction allows us to easily show that the Papadopoulos -Tseytlin ansatz for IIB solutions on T 1,1 is a consistent truncation. This explicit reduction provides an organizing principle for the linearized spectrum around the warped deformed conifold as well as the baryonic branch and should have applications to the physics of flux compactifications with warped throats.

Bena, Iosif; Giecold, Gregory; Grańa, Mariana; Halmagyi, Nick; Orsi, Francesco

2011-04-01

214

A dominant-negative mutation within AtMYB90 blocks flower pigment production in transgenic tobacco.  

Technology Transfer Automated Retrieval System (TEKTRAN)

During de novo shoot induction in cultured transgenic tobacco callus a spontaneous mutation within the coding region of a AtMYB90 transgene produced a plant line in which the original transgene-induced over-pigmented phenotype (dark red/purple from anthocyanin overproduction in most tissues) was los...

215

Pharmacological characterisation of the GlyT-1 glycine transporter using two novel radioligands.  

PubMed

Inhibitors of the glycine transporter GlyT-1 are being developed as potential treatments for schizophrenia. Here we report on the use of two novel radioligands, [(3)H]-SB-733993 and [(3)H]-GSK931145, for the characterisation of GlyT-1 in both cells and native tissue. Binding was evaluated in membranes either from HEK293 cells expressing recombinant human GlyT-1 (hGlyT-1) or from rat cerebral cortex. Specific binding of both [(3)H]-SB-733993 and [(3)H]-GSK931145 to hGlyT-1 HEK293 cell membranes and rat cerebral cortex membranes was saturable and comprised >90% of total binding. K(d) and B(max) values for the two radioligands were fairly similar, with K(d) values of 1-2 nM and B(max) values of around 7000 fmol/mg protein in hGlyT-1 membranes and 3000 fmol/mg protein in rat cortex membranes. Association of [(3)H]-SB-733993 was faster, with binding reaching equilibrium within 30 min compared with 90 min for [(3)H]-GSK931145. Dissociation was also much slower for [(3)H]-GSK931145 than for [(3)H]-SB-733993, with 50% of specific binding being dissociated by approximately 40 min and 5 min, respectively. Autoradiography studies with [(3)H]-GSK931145 showed widespread distribution of binding in rat brain, with generally higher binding in caudal compared with rostral areas. Initial studies in human frontal cortex membranes showed clear specific binding of [(3)H]-GSK931145, though with much lower density (B(max) 570 fmol/mg protein) and slightly lower affinity (K(d) 4.5 nM) compared with rat cortex. A human brain autoradiography study showed higher specific binding in cerebellum compared with frontal cortex. All GlyT-1 inhibitors tested, as well as glycine itself, competed fully for the binding of both [(3)H]-SB-733993 and [(3)H]-GSK931145 in both hGlyT-1 and rat cortex membranes. Studies on the effect of varying NaCl concentration showed that [(3)H]-SB-733993 binding was reduced by >90% in the absence of added Na(+) ions, whilst [(3)H]-GSK931145 binding was unaffected. Glycine produced concentration-dependent decreases in binding affinity of both radioligands without major changes in B(max) values, suggesting that both [(3)H]-SB-733993 and [(3)H]-GSK931145 bind to sites on GlyT-1 that are orthosteric to the site at which glycine itself binds. Overall, these results show that both [(3)H]-SB-733993 and [(3)H]-GSK931145 are useful radioligands for studies on GlyT-1 in both cell lines and native tissues, with [(3)H]-GSK931145 being the radioligand of choice for further studies on GlyT-1 expression and pharmacology. PMID:20691713

Herdon, Hugh J; Roberts, Jennifer C; Coulton, Steve; Porter, Rod A

2010-08-05

216

Wettability and fluid saturations determined from NMR T1 distributions.  

PubMed

The abundance and distribution of brine and decane are determined from T1 distributions at different stages of a water-flood test in water-wet and oil-wet chalks. The T1 distributions generated from multi-exponential decomposition of inversion-recovery data provide more information than obtained from stretched and bi-exponential fits. Chalk samples because of their uniform pore size and ideal sedimentary rocks for NMR investigations of wettability since water and decane interactions with pore walls of differing wettability are easily distinguished. PMID:8170297

Howard, J J

1994-01-01

217

BAC TransgeneOmics  

PubMed Central

The interpretation of genome sequences requires reliable and standardized methods to assess protein function at high throughput. Here we describe a fast and reliable pipeline to study protein function in mammalian cells based on protein tagging in bacterial artificial chromosomes (BACs). The large size of the BAC transgenes ensures the presence of most, if not all, regulatory elements and results in expression that closely matches that of the endogenous gene. We show that BAC transgenes can be rapidly and reliably generated using 96-well-format recombineering. After stable transfection of these transgenes into human tissue culture cells or mouse embryonic stem cells, the localization, protein-protein and/or protein-DNA interactions of the tagged protein are studied using generic, tag-based assays. The same high-throughput approach will be generally applicable to other model systems.

Poser, Ina; Sarov, Mihail; Hutchins, James R A; Heriche, Jean-Karim; Toyoda, Yusuke; Pozniakovsky, Andrei; Weigl, Daniela; Nitzsche, Anja; Hegemann, Bjorn; Bird, Alexander W; Pelletier, Laurence; Kittler, Ralf; Hua, Sujun; Naumann, Ronald; Augsburg, Martina; Sykora, Martina M; Hofemeister, Helmut; Zhang, Youming; Nasmyth, Kim; White, Kevin P; Dietzel, Steffen; Mechtler, Karl; Durbin, Richard; Stewart, A Francis; Peters, Jan-Michael; Buchholz, Frank; Hyman, Anthony A

2009-01-01

218

Genetic approaches for studying transgene inheritance and genetic recombination in three successive generations of transformed tobacco  

PubMed Central

Transgene integration into plant genomes is a complex process accompanied by molecular rearrangements. Classic methods that are normally used to study transgenic population genetics are generally inadequate for assessing such integration. Two major characteristics of transgenic populations are that a transgenic genome may harbor many copies of the transgene and that molecular rearrangements can create an unstable transgenic locus. In this work, we examined the segregation of T1, T2 and T3 transgenic tobacco progenies. Since transfer DNA (T-DNA) contains the NptII selectable marker gene that confers resistance to kanamycin, we used this characteristic in developing a method to estimate the number of functional inserts integrated into the genome. This approach was based on calculation of the theoretical segregation ratios in successive generations. Mendelian ratios of 3:1, 15:1 and 63:1 were confirmed for five transformation events whereas six transformation events yielded non-segregating progenies, a finding that raised questions about causal factors. A second approach based on a maximum likelihood method was performed to estimate recombination frequencies between linked inserts. Recombination estimates varied among transformation events and over generations. Some transgenic loci were unstable and evolved continuously to segregate independently in the T3 generation. Recombination and amplification of the transgene and filler DNA yielded additional transformed genotypes.

Tizaoui, Kalthoum; Kchouk, Mohamed Elyes

2012-01-01

219

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, SrTiO3, KTaO3 and CaTiO3, 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 CaTiO3, T1 monotonically increases with temperature and no clear saturation is discernible at high temperatures. For KTaO3, 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 KTiO3, SrTiO3 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 SrTiO3 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 SrTiO3. 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 CaTiO3 over the entire temperature range under consideration, whereas the fitting for KTaO3 requires two different ?, namely, ??260 above the dip temperature and ??40 below it. Analogously, two ? are also required for SrTiO3. Below the dip temperature, a very good fitting can be obtained with ??40. We did not try to fit the high temperature data of SrTiO3, 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 KTaO3. Assuming the AFD transition as the cause of the dip in SrTiO3, 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. The quantum temperature (T1) behaviors of three incipient ferroelectrics are investigated. A broad dip is found around 105 K in T1 with strontium titanate (ST). This dip is argued to be subsequent to the anti-ferrodistortive transition in ST.An anisotropic rotor model is forwarded to explain such dip phenomena. This model also applies to other two compounds and comparison with experiments is made.

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

2012-01-01

220

[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

221

An Initial In Vitro Investigation into the Potential Therapeutic Use of SupT1 Cells to Prevent AIDS in HIV-Seropositive Individuals  

PubMed Central

HIV infection usually leads to a progressive decline in number and functionality of CD4+ T lymphocytes, resulting in AIDS development. In this study, I investigated the strategy of using inoculated SupT1 cells to move infection from HIV-1 X4 strains toward the inoculated cells, which should theoretically prevent infection and depletion of normal CD4+ T cells, preventing the development of AIDS-related pathologies. Interestingly, the persistent in vitro replication in SupT1 cells renders the virus less cytopathic and more sensitive to antibody-mediated neutralization, suggesting that replication of the virus in the inoculated SupT1 cells may have a vaccination effect in the long run. In order to mimic the scenario of a therapy in which SupT1 cells are inoculated in an HIV-seropositive patient, I used infected SupT1/PBMC cocultures and a series of control experiments. Infections were done with equal amounts of the wild type HIV-1 LAI virus. The SupT1 CD4+CD8+ T cell population was distinguished from the PBMC CD4+CD8? T cell population by FACS analysis. The results of this study show that the virus-mediated killing of primary CD4+ T cells in the SupT1/PBMC cocultures was significantly delayed, suggesting that the preferential infection of SupT1 cells can induce the virus to spare primary CD4+ T cells from infection and depletion. The preferential infection of SupT1 cells can be explained by the higher viral tropism for the SupT1 cell line. In conclusion, this study demonstrates that it's possible in an in vitro system to use SupT1 cells to prevent HIV infection of primary CD4+ T cells, suggesting that further exploration of the SupT1 cell line as a cell-based therapy against HIV-1 may prove worthwhile.

Fior, Jonathan

2012-01-01

222

Multiple effects of genetic background on variegated transgene expression in mice.  

PubMed

BLG/7 transgenic mice express an ovine beta-lactoglobulin transgene during lactation. Unusually, transgene expression levels in milk differ between siblings. This variable expression is due to variegated transgene expression in the mammary gland and is reminiscent of position-effect variegation. The BLG/7 line was created and maintained on a mixed CBA x C57BL/6 background. We have investigated the effect on transgene expression of backcrossing for 13 generations into these backgrounds. Variable transgene expression was observed in all populations examined, confirming that it is an inherent property of the transgene array at its site of integration. There were also strain-specific effects on transgene expression that appear to be independent of the inherent variegation. The transgene, compared to endogenous milk protein genes, is specifically susceptible to inbreeding depression. Outcrossing restored transgene expression levels to that of the parental population; thus suppression was not inherited. Finally, no generation-dependent decrease in mean expression levels was observed in the parental population. Thus, although the BLG/7 transgene is expressed in a variegated manner, there was no generation-associated accumulated silencing of transgene expression. PMID:11901126

Opsahl, Margaret L; McClenaghan, Margaret; Springbett, Anthea; Reid, Sarah; Lathe, Richard; Colman, Alan; Whitelaw, C Bruce A

2002-03-01

223

Multiple effects of genetic background on variegated transgene expression in mice.  

PubMed Central

BLG/7 transgenic mice express an ovine beta-lactoglobulin transgene during lactation. Unusually, transgene expression levels in milk differ between siblings. This variable expression is due to variegated transgene expression in the mammary gland and is reminiscent of position-effect variegation. The BLG/7 line was created and maintained on a mixed CBA x C57BL/6 background. We have investigated the effect on transgene expression of backcrossing for 13 generations into these backgrounds. Variable transgene expression was observed in all populations examined, confirming that it is an inherent property of the transgene array at its site of integration. There were also strain-specific effects on transgene expression that appear to be independent of the inherent variegation. The transgene, compared to endogenous milk protein genes, is specifically susceptible to inbreeding depression. Outcrossing restored transgene expression levels to that of the parental population; thus suppression was not inherited. Finally, no generation-dependent decrease in mean expression levels was observed in the parental population. Thus, although the BLG/7 transgene is expressed in a variegated manner, there was no generation-associated accumulated silencing of transgene expression.

Opsahl, Margaret L; McClenaghan, Margaret; Springbett, Anthea; Reid, Sarah; Lathe, Richard; Colman, Alan; Whitelaw, C Bruce A

2002-01-01

224

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

225

Traffic Characteristics of the T1 NSFNET Backbone  

Microsoft Academic Search

This paper presents the results of a measurementstudy of the T1 NSFNET backbone. We first discussthe measurement environment and approach to datacollection. We then present measurements results for:long-term growth in traffic volume, including attributionto domains and protocols; trend in average packetsize on the network, both over long and medium termintervals; most popular sources, destinations, and sitepairs; traffic locality; international distribution

Kimberly C. Claffy; George C. Polyzos; Hans-werner Braun

1993-01-01

226

Characterization of the VIP receptor from SUP T1 lymphoblasts  

Microsoft Academic Search

The SUP T1 lymphoblasts express an original subtype of VIP receptors characterized by a high affinity for the VIP analogue from lizard venom named helodermin, a preference for the neuropeptide PACAP-38 over PACAP-27 and VIP, and an extremely low affinity for secretin. The molecular cloning of that receptor revealed its identity with the VIP2 receptor subtype first cloned in rat

Patrick Robberecht; Philippe Gourlet; Pascale Vertongen; Michal Svoboda

1996-01-01

227

Adiabatic inversion pulses for myocardial T1 mapping.  

PubMed

PURPOSE: To evaluate the error in T1 estimates using inversion-recovery-based T1 mapping due to imperfect inversion and to perform a systematic study of adiabatic inversion pulse designs in order to maximize inversion efficiency for values of transverse relaxation (T2) in the myocardium subject to a peak power constraint. METHODS: The inversion factor for hyperbolic secant and tangent/hyperbolic tangent adiabatic full passage waveforms was calculated using Bloch equations. A brute-force search was conducted for design parameters: pulse duration, frequency range, shape parameters, and peak amplitude. A design was selected that maximized the inversion factor over a specified range of amplitude and off-resonance and validated using phantom measurements. Empirical correction for imperfect inversion was performed. RESULTS: The tangent/hyperbolic tangent adiabatic pulse was found to outperform hyperbolic secant designs and achieve an inversion factor of 0.96 within ±150 Hz over 25% amplitude range with 14.7 µT peak amplitude. T1 mapping errors of the selected design due to imperfect inversion was ?4% and could be corrected to <1%. CONCLUSIONS: Nonideal inversion leads to significant errors in inversion-recovery-based T1 mapping. The inversion efficiency of adiabatic pulses is sensitive to transverse relaxation. The tangent/hyperbolic tangent design achieved the best performance subject to the peak amplitude constraint. Magn Reson Med, 2013. © 2013 Wiley Periodicals, Inc. PMID:23722695

Kellman, Peter; Herzka, Daniel A; Hansen, Michael Schacht

2013-05-30

228

A robust methodology for in vivo T1 mapping.  

PubMed

In this article, a robust methodology for in vivo T(1) mapping is presented. The approach combines a gold standard scanning procedure with a novel fitting procedure. Fitting complex data to a five-parameter model ensures accuracy and precision of the T(1) estimation. A reduced-dimension nonlinear least squares method is proposed. This method turns the complicated multi-parameter minimization into a straightforward one-dimensional search. As the range of possible T(1) values is known, a global grid search can be used, ensuring that a global optimal solution is found. When only magnitude data are available, the algorithm is adapted to concurrently restore polarity. The performance of the new algorithm is demonstrated in simulations and phantom experiments. The new algorithm is as accurate and precise as the conventionally used Levenberg-Marquardt algorithm but much faster. This gain in speed makes the use of the five-parameter model viable. In addition, the new algorithm does not require initialization of the search parameters. Finally, the methodology is applied in vivo to conventional brain imaging and to skin imaging. T(1) values are estimated for white matter and gray matter at 1.5 T and for dermis, hypodermis, and muscle at 1.5 T, 3 T, and 7 T. PMID:20564597

Barral, Joëlle K; Gudmundson, Erik; Stikov, Nikola; Etezadi-Amoli, Maryam; Stoica, Petre; Nishimura, Dwight G

2010-10-01

229

Overproduction of Arabidopsis thaliana FeSOD confers oxidative stress tolerance to transgenic maize.  

PubMed

Transgenic maize (Zea mays L.) plants have been generated by particle gun bombardment that overproduce an Arabidopsis thaliana iron superoxide dismutase (FeSOD). To target this enzyme into chloroplasts, the mature Fesod coding sequence was fused to a chloroplast transit peptide from a pea ribulose-1,5-bisphosphate carboxylase gene. Expression of the chimeric gene was driven by the CaMV 35S promoter. Growth characteristics and in vitro oxidative stress tolerance of transgenic lines grown in control and chilling temperatures were evaluated. The transgenic line with the highest transgenic FeSOD activities had enhanced tolerance toward methyl viologen and had increased growth rates. PMID:10427774

Van Breusegem, F; Slooten, L; Stassart, J M; Moens, T; Botterman, J; Van Montagu, M; Inzé, D

1999-05-01

230

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.

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

2006-01-01

231

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

PubMed

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

2006-03-23

232

Reduced cardiac hypertrophy and altered blood pressure control in transgenic rats with the human tissue kallikrein gene  

Microsoft Academic Search

To evaluate the cardiovascular actions of kinins, we established a transgenic rat line harboring the human tissue kallikrein gene, TGR(hKLK1). Under the control of the zinc-inducible metallothionein promoter, the transgene was expressed in most tissues including the heart, kidney, lung, and brain, and human kallikrein was detected in the urine of transgenic animals. Transgenic rats had a lower 24-h mean

J.-A. Silva Jr.; Ronaldo C. Araujo; Ovidiu Baltatu; Suzana M. Oliveira; Carsten Tschöpe; Edwin Fink; Sigrid Hoffmann; Ralph Plehm; Karl X. Chai; Lee Chao; Julie Chao; Detlev Ganten; Joăo B. Pesquero; Michael Bader

2000-01-01

233

Responses of MxPPO overexpressing transgenic tall fescue plants to two diphenyl-ether herbicides, oxyfluorfen and acifluorfen  

Microsoft Academic Search

We generated transgenic tall fescue (Festuca arundinacea Schreb. cv. Kentucky-31) plants harboring a synthetic Myxococcus xanthus protoporphyrinogen oxidase (MxPPO) gene through Agrobacterium-mediated gene transfer. Successful integration of the transgene into the genome of transgenic plants confirmed by polymerase\\u000a chain reaction (PCR) and Southern blot analysis, and the functional expression of the MxPPO gene at the mRNA level in transgenic lines

Ki-Won Lee; Nagib Ahsan; Sang-Hoon Lee; Dong-Gi Lee; Kyung-Hee Kim; Iftekhar Alam; Suk-Yoon Kwon; Jin-Seog Kim; Kyoungwhan Back; Sung Sil Lee; Byung-Hyun Lee

2008-01-01

234

A future for transgenic livestock  

Microsoft Academic Search

The techniques that are used to generate transgenic livestock are inefficient and expensive. This, coupled with the fact that most agriculturally relevant traits are complex and controlled by more than one gene, has restricted the use of transgenic technology. New methods for modifying the genome will underpin a resurgence of research using transgenic livestock. This will not only increase our

Bruce Whitelaw; John Clark

2003-01-01

235

Population genetics of transgene containment  

Microsoft Academic Search

Several strategies have been proposed for creating transgenic cultivars from which transgene escape to wild relatives would seem unlikely; for example, to impede escape through pollen, a transgene could be inserted into chloroplast DNA (cpDNA), which in many crops is rarely transmitted through pollen. None of these strategies would be failsafe; for example, the rate of cpDNA transmission through pollen

Ralph Haygood; Anthony R. Ives; David A. Andow

2004-01-01

236

Transgenic Crops for Herbicide Resistance  

Technology Transfer Automated Retrieval System (TEKTRAN)

Since their introduction in 1995, crops made resistant to the broad-spectrum herbicides glyphosate and glufosinate with transgenes are widely available and used in much of the world. As of 2008, over 80% of the transgenic crops grown world-wide have this transgenic trait. This technology has had m...

237

The Virtual Transgenic Fly Lab  

NSDL National Science Digital Library

The lab will familiarize you with the science and techniques used to make transgenic flies. Transgenic organisms, which contain DNA that is inserted experimentally, are used to study many biological processes. In this lab, you will create a transgenic fly to study circadian rhythms.

Peter J. Bruns, Ph.D. (Howard Hughes Medical Institute;)

2008-04-16

238

Site-specific recombination of a transgene in fertilized eggs by transient expression of Cre recombinase.  

PubMed Central

An efficient method of transgene modulation in fertilized eggs has been developed that uses the Cre/loxP recombination system. Twelve transgenic mouse lines carrying a chicken beta-actin promoter-loxP-chloramphenicol acetyltransferase (CAT) gene-loxP-beta-galactosidase gene construct were produced. After selection of the line showing the highest expression of the CAT gene in a variety of tissues, eggs of this line were injected in the male or female pronucleus with a Cre expression vector placed under the control of the chicken beta-actin promoter and kept in a circular form to avoid genomic integration. This resulted in a transient expression of Cre in the eggs, leading to recombination of the transgene as detected by galactosidase expression and DNA analysis. Recombination was completed before the morula stage with both types of pronuclear injections and occurred with a very high frequency; no mosaicism, no incomplete recombination, and no integration of the Cre sequence were observed in 18 mice born with this modified transgene. The beta-galactosidase gene was expressed in various tissues at levels comparable to those found for the CAT gene in the founder line. This Cre transient expression system should be useful for breeding transgenic lines in which transgene expression leads to sterility or lethality--in particular, for selecting transgenic lines with high expression of a potentially lethal transgene whose full activity is difficult to explore in a conventional transgenic system because of the risk of selecting for transgenic lines carrying only poorly expressed transgenes. Images Fig. 1 Fig. 2 Fig. 3

Araki, K; Araki, M; Miyazaki, J; Vassalli, P

1995-01-01

239

Transgenic models of Huntington's disease.  

PubMed Central

Huntington's disease (HD) is an inherited neurodegenerative disorder caused by a CAG-polyglutamine repeat expansion. A mouse model of this disease has been generated by the introduction of exon 1 of the human HD gene carrying highly expanded CAG repeats into the mouse germ line (R6 lines). Transgenic mice develop a progressive neurological phenotype with a movement disorder and weight loss similar to that in HD. We have previously identified neuronal inclusions in the brains of these mice that have subsequently been established as the pathological hallmark of polyglutamine disease. Inclusions are present before symptoms, which in turn occur long before any selective neuronal cell death can be identified. We have extended the search for inclusions to skeletal muscle, which, like brain, contains terminally differentiated cells. We have conducted an investigation into the skeletal muscle atrophy that occurs in the R6 lines, (i) to provide possible insights into the muscle bulk loss observed in HD patients, and (ii) to conduct a parallel analysis into the consequence of inclusion formation to that being performed in brain. The identification of inclusions in skeletal muscle might be additionally useful in monitoring the ability of drugs to prevent inclusion formation in vivo.

Sathasivam, K; Hobbs, C; Mangiarini, L; Mahal, A; Turmaine, M; Doherty, P; Davies, S W; Bates, G P

1999-01-01

240

Viable transgenic goats derived from skin cells.  

PubMed

The current study was undertaken to evaluate the possibility of expanding transgenic goat herds by means of somatic cell nuclear transfer (NT) using transgenic goat cells as nucleus donors. Skin cells from adult, transgenic goats were first synchronized at quiescent stage (G0) by serum starvation and then induced to exit G0 and proceed into G1. Oocytes collected from superovulated donors were enucleated, karyoplast-cytoplast couplets were constructed, and then fused and activated simultaneously by a single electrical pulse. Fused couplets were either co-cultured with oviductal cells in TCM-199 medium (in vitro culture) or transferred to intermediate recipient goat oviducts (in vivo culture) until final transfer. The resulting morulae and blastocysts were transferred to the final recipients. Pregnancies were confirmed by ultrasonography 25-30 days after embryo transfer. In vitro cultured NT embryos developed to morulae and blastocyst stages but did not produce any pregnancies while 30% (6/20) of the in vivo derived morulae and blastocysts produced pregnancies. Two of these pregnancies were resorbed early in gestation. Of the four recipients that maintained pregnancies to term, two delivered dead fetuses 2-3 days after their due dates, and two recipients gave birth to healthy kids at term. Fluorescence in situ hybridization (FISH) analysis confirmed that both kids were transgenic and had integration sites consistent with those observed in the adult cell line. PMID:15359599

Behboodi, Esmail; Memili, Erdogan; Melican, David T; Destrempes, Margaret M; Overton, Susan A; Williams, Jennifer L; Flanagan, Peter A; Butler, Robin E; Liem, Hetty; Chen, Li How; Meade, Harry M; Gavin, William G; Echelard, Yann

2004-06-01

241

Heart and bone tumors in transgenic mice.  

PubMed Central

Tissue-specific tumorigenesis can be induced in transgenic mice by the directed expression of simian virus 40 (SV40) large tumor (T) antigen. In an attempt to determine the susceptibility of haploid, round spermatids to neoplastic transformation by this oncogene, transgenic mice were generated that harbored a chimeric gene composed of the SV40 T-antigen genes fused to the 5' and 3' flanking sequences of the mouse protamine 1 gene. The transgene was expressed in round spermatids and, surprisingly, in the heart and temporal bone as well. Expression in the heart resulted in rhabdomyosarcomas that always appeared in the right atrium. Bilateral osteosarcomas developed within the petrous portion of the temporal bone. No testicular pathology was observed. T-antigen immunostaining was readily detected in tumor tissue but not in the testis. In addition, SV40 transcripts were processed differently in testis and tumor tissue. Transgenic mouse lines were established that routinely develop these tumors, and they should provide a valuable resource for studies involving cardiac and bone physiology and neoplasia. The atrial tumor cells can be maintained in vitro and some continue to display a cardiac muscle phenotype. Images

Behringer, R R; Peschon, J J; Messing, A; Gartside, C L; Hauschka, S D; Palmiter, R D; Brinster, R L

1988-01-01

242

Transgenic zebrafish produced by retroviral infection of in vitro-cultured sperm.  

PubMed

Transgenic modification of sperm before fertilization has distinct advantages over conventional transgenic methods. The primary advantage is that the mosaicism inherent in those other techniques is avoided. A culture system using primary cultures of zebrafish male germ cells, in which the differentiation from spermatogonia to functional sperm can occur in vitro, provides the opportunity for genetic modification of sperm in vitro. Here, we report the production of transgenic zebrafish from cultured sperm. The sperm were differentiated from premeiotic germ cells infected with a pseudotyped retrovirus in vitro. The collected sperm were used to perform successful in vitro fertilizations, and transgenic embryos were identified. The transgenic fish transmitted the proviral integration to the next generation in a Mendelian fashion. We report the generation of a transgenic animal by cultured sperm and open the door to many exciting possibilities for the rapid generation of transgenic lines in model organisms such as zebrafish or other animal systems that are otherwise intractable to transgenesis. PMID:14745028

Kurita, Kayoko; Burgess, Shawn M; Sakai, Noriyoshi

2004-01-26

243

Expression of Transgenic APP mRNA Is the Key Determinant for Beta-Amyloid Deposition in PS2APP Transgenic Mice  

Microsoft Academic Search

Background: Alzheimer’s disease is the most common cause of dementia occurring in the elderly. The identification of the genetic factors in the familial forms of the disease enabled the generation of transgenic animals which reproduce an essential part of its pathology. Various lines of transgenic mice expressing human wild-type or mutated APP have been reported. The phenotype expressed in these

Laurence Ozmen; Anita Albientz; Christian Czech; Helmut Jacobsen

2009-01-01

244

Limited Fitness Advantages of Crop-Weed Hybrid Progeny Containing Insect-Resistant Transgenes (Bt/CpTI) in Transgenic Rice Field  

PubMed Central

Background The spread of insect-resistance transgenes from genetically engineered (GE) rice to its coexisting weedy rice (O. sativa f. spontanea) populations via gene flow creates a major concern for commercial GE rice cultivation. Transgene flow to weedy rice seems unavoidable. Therefore, characterization of potential fitness effect brought by the transgenes is essential to assess environmental consequences caused by crop-weed transgene flow. Methodology/Principal Findings Field performance of fitness-related traits was assessed in advanced hybrid progeny of F4 generation derived from a cross between an insect-resistant transgenic (Bt/CpTI) rice line and a weedy strain. The performance of transgene-positive hybrid progeny was compared with the transgene-negative progeny and weedy parent in pure and mixed planting of transgenic and nontransgenic plants under environmental conditions with natural vs. low insect pressure. Results showed that under natural insect pressure the insect-resistant transgenes could effectively suppress target insects and bring significantly increased fitness to transgenic plants in pure planting, compared with nontransgenic plants (including weedy parent). In contrast, no significant differences in fitness were detected under low insect pressure. However, such increase in fitness was not detected in the mixed planting of transgenic and nontransgenic plants due to significantly reduced insect pressure. Conclusions/Significance Insect-resistance transgenes may have limited fitness advantages to hybrid progeny resulted from crop-weed transgene flow owning to the significantly reduced ambient target insect pressure when an insect-resistant GE crop is grown. Given that the extensive cultivation of an insect-resistant GE crop will ultimately reduce the target insect pressure, the rapid spread of insect-resistance transgenes in weedy populations in commercial GE crop fields may be not likely to happen.

Yang, Xiao; Wang, Feng; Su, Jun; Lu, Bao-Rong

2012-01-01

245

Spontaneous short-range silencing of a GFP transgene in Nicotiana benthamiana is possibly mediated by small quantities of siRNA that do not trigger systemic silencing  

Microsoft Academic Search

Summary A green fluorescent protein (GFP) transgene under the control of the 35S cauliflower mosaic virus (CaMV) promoter was introduced by Agrobacterium-mediated transformation intoNicotiana benthamiana to generate fourteen transgenic lines. Homozygous lines that contained one or two copies of the transgene showed great variation of GFP expression under ultraviolet (UV) light, which allowed classification into three types of transgenic plants.

Kriton Kalantidis; Mina Tsagris; Martin Tabler

2006-01-01

246

Resistance to Alternaria brassicicola in transgenic broccoli expressing a Trichoderma harzianum endochitinase gene  

Microsoft Academic Search

Transgenic broccoli plants expressing a Trichoderma harzianum endochitinase gene were obtained by Agrobacterium tumefaciens-mediated transformation. PCR and Southern blot analysis confirmed the presence of the gene in plants initially selected via resistance to kanamycin. Primary transformants (T0) and selfed progeny (T1) were examined for expression of the endochitinase gene using a fluorometric assay and for their resistance to the fungal

A. A. Mora; E. D. Earle

2001-01-01

247

[Transgenerational transmission of bovine satellite DNA in transgenic mice].  

PubMed

Genetical, cytogenetical and molecular analysis was made for 5 generations of mice transgenic for bovine satellite DNA (Sat). In all cases transgenic mice were generated by crosses of transgenic males and females with normal (CBA x C57B1) mice. No abnormalities in the founder development were noticed. A normal (near 50 %) ratio of transgenic and nontransgenic offsprings was observed in blastocysts. However, profound differences occurred in the rate of transgene bearing offsprings, depending on the sex of grandparents rather than of parents. The grandfather Sat transmission resulted in the appearance of 0-52.4 % transgenic grandchildren, whereas the grandmother transmission ended in the theoretically expected rate. This means that stabilization of transsatellite took place upon the female germ line transmission (a positive grandmother effect). It is essential that in hemizygous transsatellite mice Sat integration led to the occurrence of mammary tumors, inflammation of uterine horns, and infringement of mother care of transgenic females. Simultaneous FISH and G-banding showed Sat to be localized in the internal region of chromosome 12 near Pax 9 and Brms 11 genes. Commonly, these genes are implicated in tumorigenesis as their expression decreases. Thus, a kind of silencing effect of these genes' expression may be supposed. PMID:16893059

Slominskaia, N A; Suchkova, I O; Klinskaia, T A; Zabezhinskaia, M A; Patkin, E L

2006-01-01

248

Tunneling at ?T=1 in quantum Hall bilayers  

NASA Astrophysics Data System (ADS)

Interlayer tunneling measurements in the strongly correlated bilayer quantized Hall phase at ?T=1 are reported. The maximum, or critical, current for tunneling at ?T=1 is shown to be a well-defined global property of the coherent phase, insensitive to extrinsic circuit effects and the precise configuration used to measure it, but also exhibiting a surprising scaling behavior with temperature. Comparisons between the experimentally observed tunneling characteristics and a recent theory are favorable at high temperatures, but not at low temperatures where the tunneling closely resembles the dc Josephson effect. The zero-bias tunneling resistance becomes extremely small at low temperatures, vastly less than that observed at zero magnetic field, but nonetheless remains finite. The temperature dependence of this tunneling resistance is similar to that of the ordinary in-plane resistivity of the quantum Hall phase.

Nandi, D.; Khaire, T.; Finck, A. D. K.; Eisenstein, J. P.; Pfeiffer, L. N.; West, K. W.

2013-10-01

249

Ball lightning with a lifetime t?1 s  

Microsoft Academic Search

Among luminous formations acknowledged as examples of artificial ball lightning with lifetimes t?1 s, examples are presented whose nature is well described by a weakly ionized plasma with a gas temperature T?0.5 eV. It is shown that such lifetimes do not contradict the estimates of P. L. Kapitsa if it is taken into account the\\u000a fact that the plasma under

A. M. Boichenko

1999-01-01

250

Effect of ploidy and homozygosity on transgene expression in primary tobacco transformants and their androgenetic progenies  

Microsoft Academic Search

Expression of a transgene is rarely analysed in the androgenetic progenies of the transgenic plants. Here, we report differential\\u000a transgene expression in androgenetic haploid and doubled haploid (DH) tobacco plants as compared to the diploid parental lines,\\u000a thus demonstrating a gene dosage effect. Using Agrobacterium-mediated transformation, and bacterial reporter genes encoding neomycin phosphotransferase (nptII) and ?-glucuronidase (uidA\\/ GUS), driven respectively

A. Beaujean; R. S. Sangwan; M. Hodges; B. S. Sangwan-Norreel

1998-01-01

251

Resistance pattern and antioxidant enzyme profiles of protoporphyrinogen oxidase (PROTOX) inhibitor-resistant transgenic rice  

Microsoft Academic Search

We quantified the resistance levels of transgenic rice plants, expressing Myxococcus xanthus protoporphyrinogen oxidase (PROTOX) in chloroplasts and mitochondria, to PROTOX inhibitors, acifluorfen, oxyfluorfen, carfentrazone-ethyl, and oxadiazon. We also determined whether active oxygen species-scavenging enzymes are involved in the resistance mechanism of transgenic rice. The transgenic rice line M4 was about >200-fold more resistant to oxyfluorfen than the wild-type (WT).

Ha Il Jung; Yong In Kuk; Kyoungwhan Back; Nilda R. Burgos

2008-01-01

252

Model Selection for DCE-T1 Studies in Glioblastoma  

PubMed Central

Dynamic Contrast Enhanced T1-Weighted MRI (DCE-T1) using the contrast agent (CA) Gd-DTPA was performed on ten patients with glioblastoma (GBM). Nested models with as many as three parameters were employed to estimate plasma volume (vp), or vp and forward vascular transfer constant (Ktrans), or vp, Ktrans, and the reverse vascular transfer constant (kep). These constituted Models 1, 2, and 3, respectively. Model 1 predominated in normal non-leaky brain tissue, showing little or no leakage of CA. Model 3 predominated in regions associated with aggressive portions of the tumor, and Model 2 bordered Model 3 regions, showing leakage at reduced rates. In the patient sample, vp was about four times that of white matter in the enhancing part of the tumor. Ktrans varied by a factor of ten between the Model 2 (1.9 ×10?3 min?1) and Model 3 regions (1.9 ×10?2 min?1). The mean calculated interstitial space (Model 3) was 5.5%. In Model 3 regions, excellent curve fits were obtained to summarize concentration-time data (mean R2 = 0.99). We conclude that the three parameters of the Standard Model are sufficient to fit DCE-T1 data in GBM under the conditions of the experiment.

Bagher-Ebadian, Hassan; Jain, Rajan; Nejad-Davarani, Siamak P.; Mikkelsen, Tom; Lu, Mei; Jiang, Quan; Scarpace, Lisa; Arbab, Ali S.; Narang, Jayant; Soltanian-Zadeh, Hamid; Paudyal, Ramesh; Ewing, James. R.

2011-01-01

253

Transanal endoscopic microsurgery in treatment of rectal adenomas and T1 low-risk carcinomas  

PubMed Central

Background Transanal endoscopic microsurgery as a local therapy option for rectal neoplasms is a tissue-sparing technique that protects the anal sphincter. The present retrospective analysis reports the course of observation after local excision of adenomas and T1 low-risk carcinomas using transanal endoscopic microsurgery. Methods In a retrospective analysis we examined data on 279 patients for local recurrence. A total of 144 patients had a rectal adenoma (n?=?103) or a R0 resection of low-risk T1 carcinomas (n?=?41). In this collective, we also examined parameters concerning perioperative management, complications, intraoperative blood loss and duration of hospital stay. Results Patients with adenoma were on average 64.9 (range 37 to 90) years old; 83.5% of the adenomas were located 3 to 11 cm from the anocutaneous line. In adenoma patients the recurrence rate was 2.9% for an observation period of 21.8 months. The postoperative course was without any complications in 98.1% of patients. Patients with T1 low-risk carcinoma were 64.6 (range 30 to 89) years old. In all cases, an R0 resection could be performed. The recurrence rate was 9.8% for an observation period of 34.4 months. In this group the postoperative course was free of complications in 97.6% of patients. Conclusions The high efficacy of transanal endoscopic microsurgery ensures minimally invasive treatment of adenomas and low-risk T1 carcinomas with low complication rates and a low rate of therapeutic failure.

2012-01-01

254

Pharmacogenetic heterogeneity of transgene expression in muscle and tumours  

PubMed Central

Background Recombinant adenoviruses are employed to deliver a therapeutic transgene in the liver, muscle or tumour tissue. However, to rationalise this delivery approach, the factors of variation between individuals need to be identified. It is assumed that differences between inbred strains of laboratory animals are considered to reflect differences between patients. Previously we showed that transgene expression in the liver of different rat strains was dependent on the transcription efficiency of the transgene. In the present paper we investigated if transfection of muscle and tumour tissue were also subject to such variations. Methods Variation, in transgene expression, after intramuscular gene delivery was determined in different rodent strains and gene expression in tumours was investigated in different human and rodent cell lines as well as in subcutaneously implanted rodent tumours. The molecular mechanisms involved in transgene expression were dissected using an adenovirus encoding luciferase. The luciferase activity, the viral DNA copies and the luciferase transcripts were assessed in cultured cells as well as in the tissues. Results Large differences of luciferase activity, up to 2 logs, were observed between different rodent strains after intramuscular injection of Ad Luciferase. This inter-strain variation of transgene expression was due to a difference in transcription efficiency. The transgene expression level in tumour cell lines of different tissue origin could be explained largely by the difference of infectibility to the adenovirus. In contrast, the main step responsible for luciferase activity variation, between six human breast cancer cell lines with similar phenotype, was at the transcriptional level. Conclusion Difference in transcriptional efficiency in muscles as observed between different inbred strains and between human breast cancer cell lines may be expected to occur between individual patients. This might have important consequences for clinical gene therapy. The variation between tumour types and tissues within a species are mainly at the levels of infectivity.

Lefesvre, Pierre; Attema, Joline; van Bekkum, Dirk

2003-01-01

255

Identification, cloning and characterization of a plasma membrane zinc efflux transporter, TrZnT-1, from fugu pufferfish (Takifugu rubripes)  

PubMed Central

An orthologue of the mammalian ZnT-1 (zinc transporter-1) gene was cloned from the intestine of the torafugu pufferfish (Takifugu rubripes), demonstrating that this gene predates the evolution of land-living vertebrates. TrZnT-1 (T. rubripes ZnT-1) shares overall topology with other members of the ZnT-1 family of zinc transporters, with six TMs (transmembrane domains) including a large histidine-rich intracellular loop between TM IV and V and intracellular C- and N-termini. Expression of TrZnT-1 in a metallothionein acquiescent cell line suggested that this protein reduces intracellular Zn2+ levels. Manipulation of the transporting media showed that several externally applied hydrominerals had no effect on TrZnT-1 activity. However, addition of N-ethylmaleimide increased TrZnT-1-mediated transport, possibly by increasing intracellular free Zn2+ levels by Zn2+ release from carrier proteins. Generation of a specific antibody and subsequent immunocytochemistry on fixed cells overexpressing TrZnT-1 indicated that the protein is localized to the plasma membrane in these cells. The genomic organization of TrZnT-1 is the same as that in mammals with two exons. The upstream regulatory region of the TrZnT-1 gene contains several putative cis-acting elements, including metal-response elements and an Sp1 site. Analysis of the DNA contigs surrounding the TrZnT-1 gene reveal limited synteny between corresponding regions in the rat, mouse and human; however, this was very low, with only two syntenic genes, ZnT-1 and NEK2 (never in mitosis gene A-related kinase).

Balesaria, Sara; Hogstrand, Christer

2005-01-01

256

Field and pulping performances of transgenic trees with altered lignification.  

PubMed

The agronomic and pulping performance of transgenic trees with altered lignin has been evaluated in duplicated, long-term field trials. Poplars expressing cinnamyl alcohol dehydrogenase (CAD) or caffeate/5-hydroxy-ferulate O-methyltransferase (COMT) antisense transgenes were grown for four years at two sites, in France and England. The trees remained healthy throughout the trial. Growth indicators and interactions with insects were normal. No changes in soil microbial communities were detected beneath the transgenic trees. The expected modifications to lignin were maintained in the transgenics over four years, at both sites. Kraft pulping of tree trunks showed that the reduced-CAD lines had improved characteristics, allowing easier delignification, using smaller amounts of chemicals, while yielding more high-quality pulp. This work highlights the potential of engineering wood quality for more environmentally benign papermaking without interfering with tree growth or fitness. PMID:12042866

Pilate, Gilles; Guiney, Emma; Holt, Karen; Petit-Conil, Michel; Lapierre, Catherine; Leplé, Jean-Charles; Pollet, Brigitte; Mila, Isabelle; Webster, Elizabeth A; Marstorp, Hĺkan G; Hopkins, David W; Jouanin, Lise; Boerjan, Wout; Schuch, Wolfgang; Cornu, Daniel; Halpin, Claire

2002-06-01

257

[Analysis of the transgenic rice plants derived from transformed anther calli].  

PubMed

Rice calli derived from anther culture were used as recipient to transfer a rice blight resistance gene, Xa21, into a japonica rice variety, Taipei 309, via Agrobacterium-mediated transformation. Seven green transgenic plants, including one mixoploid, two haploid, and four diploid plants, were regenerated. PCR, Southern blot, FISH and blight resistance analysis all indicated that Xa21 gene has been integrated into the T0 plant genomes. T1 generations of the four diploid T0 plants were further investigated for resistance segregation. Chi2 test showed that two T1 populations segregated with a ratio of 3:1, indicating that a single copy of Xa21 gene was integrated into the genome, whereas the segregation ratios of the other two T1 populations were non-Mendelian. Therefore, the four diploid transgenic plants should be heterozygous diploids. PMID:15633644

Jiang, Su; Chen, Cai-Yan; Cheng, Zhu-Kuan; Cai, Run; Zhai, Wen-Xue; Zhu, Li-Huang

2004-12-01

258

Transgenes for tea?  

PubMed

So far, no compelling scientific evidence has been found to suggest that the consumption of transgenic or genetically modified (GM) plants by animals or humans is more likely to cause harm than is the consumption of their conventional counterparts. Despite this lack of scientific evidence, the economic prospects for GM plants are probably limited in the short term and there is public opposition to the technology. Now is a good time to address several issues concerning GM plants, including the potential for transgenes to migrate from GM plants to gut microbes or to animal or human tissues, the consequences of consuming GM crops, either as fresh plants or as silage, and the problems caused by current legislation on GM labelling and beyond. PMID:15629853

Heritage, John

2005-01-01

259

High level production of human growth hormone in the milk of transgenic mice: the upstream region of the rabbit whey acidic protein (WAP) gene targets transgene expression to the mammary gland  

Microsoft Academic Search

The 5? flanking region (6.3 kb) of the rabbit WAP (rWAP) gene possesses important regulatory elements. This region was linked to the human growth hormone (hGH) structural gene in order to target transgene expression to the mammary gland. Thirteen lines of transgenic mice were produced. Milk could be collected from six lines of transgenic mice. In five of them, hGH

Eve Devinoy; Dominique Thepot; Marie-Georges Stinnakre; Marie-Louise Fontaine; Henri Grabowski; Claudine Puissant; Andrea Pavirani; Louis-Marie Houdebine

1994-01-01

260

T1 and susceptibility contrast at high fields  

NASA Astrophysics Data System (ADS)

Clinical imaging at high magnetic field strengths (? 3Tesla) is sought after primarily due to the increased signal strength available at these fields. This increased SNR can be used to perform: (a) high resolution imaging in the same time as at lower field strengths; (b) the same resolution imaging with much faster acquisition; and (c) functional MR imaging (fMRI), dynamic perfusion and diffusion imaging with increased sensitivity. However they are also associated with increased power deposition (SAR) due to increase in imaging frequency and longer T1 relaxation times. Longer T1s mean longer imaging times for generating good T1 contrast images. On the other hand for faster imaging, at high fields fast spin echo or magnetization prepared sequences are conventionally proposed which are, however, associated with high SAR values. Imaging with low SAR is more and more important as we move towards high fields and particularly for patients with metallic implants like pacemakers or deep brain stimulator. The SAR limit acceptable for these patients is much less than the limit acceptable for normal subjects. A new method is proposed for imaging at high fields with good contrast with simultaneous reduction in power deposition. Further, T1 based contrast optimization problem in FLASH imaging is considered for tissues with different T1s but same spin densities. The solution providing optimal imaging parameters is simplified for quick and easy computation in a clinical setting. The efficacy of the simplification is evaluated and practical limits under which the simplification can be applied are worked out. The phase difference due to variation in magnetic susceptibility property among biological tissues is another unique source of contrast which is different from the conventional T1, T2 and T2* contrast. This susceptibility based phase contrast has become more and more important at high fields, partly due to contrast generation issues due to longer T 1s and shorter T2s and partly because of the invariance of most tissue susceptibilities with field strength. This essentially ensures a constant available phase contrast between tissues across field strengths. In fact, with the increased SNR at high fields, the phase CNR actually increases with field strength which is even better. Susceptibility weighted imaging, which uniquely combines this phase and magnitude information to generate enhanced susceptibility contrast magnitude images, has proven to be an important tool in the study of various neurological conditions like, Alzheimer's, Parkinson's, Huntington's disease and multiple sclerosis even at conventional field strength of 1.5T and should have more applicability at high fields. A major issue in using phase images for susceptibility contrast, directly or as processed SWI magnitude images, is the large scale background phase variations that obscure the local susceptibility based contrast. A novel method is proposed for removing such geometrically induced large scale phase variations using a Fourier Transform based field calculation method. It is shown that the new method is capable of successfully removing the background field effects. It is shown that the new method is not only capable of successfully removing the background field effects but also helps in preserving more local phase information.

Neelavalli, Jaladhar

261

Efficient gene modulation in mouse epiblast using a Sox2Cre transgenic mouse strain  

Microsoft Academic Search

We have generated a transgenic line that expresses the Cre gene product under the regulation of a 12.5 kb upstream regulatory sequence from the Sox2 gene. Using a R26R reporter line, we show that this transgenic line induces recombination in all epiblast cells by embryonic day (E) 6.5 but little or no activity in other extraembryonic cell types at this

Shigemi Hayashi; Paula Lewis; Larysa Pevny; Andrew P. McMahon

2002-01-01

262

Cre-Dependent Expression of Multiple Transgenes in Isolated Neurons of the Adult Forebrain  

PubMed Central

Background Transgenic mice with mosaic, Golgi-staining-like expression of enhanced green fluorescent protein (EGFP) have been very useful in studying the dynamics of neuronal structure and function. In order to further investigate the molecular events regulating structural plasticity, it would be useful to express multiple proteins in the same sparse neurons, allowing co-expression of functional proteins or co-labeling of subcellular compartments with other fluorescent proteins. However, it has been difficult to obtain reproducible expression in the same subset of neurons for direct comparison of neurons expressing different functional proteins. Principal Findings Here we describe a Cre-transgenic line that allows reproducible expression of transgenic proteins of choice in a small number of neurons of the adult cortex, hippocampus, striatum, olfactory bulb, subiculum, hypothalamus, superior colliculus and amygdala. We show that using these Cre-transgenic mice, multiple Cre-dependent transgenes can be expressed together in the same isolated neurons. We also describe a Cre-dependent transgenic line expressing a membrane associated EGFP (EGFP-F). Crossed with the Cre-transgenic line, EGFP-F expression starts in the adolescent forebrain, is present in dendrites, dendritic protrusions, axons and boutons and is strong enough for acute or chronic in vivo imaging. Significance This triple transgenic approach will aid the morphological and functional characterization of neurons in various Cre-dependent transgenic mice.

Chakravarthy, Sridhara; Keck, Tara; Roelandse, Martijn; Hartman, Robin; Jeromin, Andreas; Perry, Sean; Hofer, Sonja B.; Mrsic-Flogel, Thomas; Levelt, Christiaan N.

2008-01-01

263

Transgenic control of perforin gene expression  

SciTech Connect

Perforin is a pore-forming effector molecule of CTL and NK cells. To characterize perforin gene expression and its transcriptional control mechanisms in vivo, expression of a cell surface tag, i.e., human CD4, was driven by 5.1 kb of the murin perforin 5{prime} flanking and promoter region in transgenic mice. Six out of seven transgenic lines expressed the perforin-tag hybrid gene at low to intermediate levels, depending on the integration site. Transgene expression occurred in all cells that physiologically are able to express perforin. At the whole organ level, significant amounts of transgenic mRNA and endogenous perforin mRNA were co-expressed in the lymphoid organs, as well as in the lung, the ileum, the oviduct/uterus, and the bone marrow. At the single cell level, the perforin tag was present on NK cells and on CD8{sup +}, as well as on CD4{sup +} cells. Also targeted were Thy-1.2{sup +} {gamma}{delta} T cells, but not Thy-1.2{sup -} {gamma}{delta} T cells, B cells, nor monocytes. During thymic T cell development, transgene expression occurred in double negative (CD4{sup -}CD8{sup -}) thymocytes and was detected at all subsequent stages, but exceeded the expression levels of the endogenous gene in the thymus. In conclusion, the analyzed perforin 5{prime} flanking and promoter region contains important cis-acting sequences that restrict perforin expression to T cells and NK cells, and therefore provides a unique tool for manipulating T cell and/or Nk cell-mediated immune responses in transgenic mice. On the other hand, the normal control of perforin gene expression involves at least one additional negative control mechanism that was not mediated by the transgenic promoter and upstream region. This control restricts perforin gene expression in thymically developing T cells and in most resting peripheral T cells, but can be released upon T cell activation. 43 refs., 7 figs., 1 tab.

Lichtenheld, M.G.; Podack, E.R.; Levy, R.B. [Univ. of Miami, FL (United States)

1995-03-01

264

Use of microarray hybrid capture and next-generation sequencing to identify the anatomy of a transgene  

PubMed Central

Transgenic animals are extensively used to model human disease. Typically, the transgene copy number is estimated, but the exact integration site and configuration of the foreign DNA remains uncharacterized. When transgenes have been closely examined, some unexpected configurations have been found. Here, we describe a method to recover transgene insertion sites and assess structural rearrangements of host and transgene DNA using microarray hybridization and targeted sequence capture. We used information about the transgene insertion site to develop a polymerase chain reaction genotyping assay to distinguish heterozygous from homozygous transgenic animals. Although we worked with a bacterial artificial chromosome transgenic mouse line, this method can be used to analyse the integration site and configuration of any foreign DNA in a sequenced genome.

DuBose, Amanda J.; Lichtenstein, Stephen T.; Narisu, Narisu; Bonnycastle, Lori L.; Swift, Amy J.; Chines, Peter S.; Collins, Francis S.

2013-01-01

265

Generation of Transgenic C. elegans by Biolistic Transformation  

PubMed Central

The number of laboratories using the free living nematode C. elegans is rapidly growing. The popularity of this biological model is attributed to a rapid generation time and short life span, easy and inexpensive maintenance, fully sequenced genome, and array of RNAi resources and mutant animals. Additionally, analysis of the C. elegans genome revealed a great similarity between worms and higher vertebrates, which suggests that research in worms could be an important adjunct to studies performed in whole mice or cultured cells. A powerful and important part of worm research is the ability to use transgenic animals to study gene localization and function. Transgenic animals can be created either via microinjection of the worm germline or through the use of biolistic bombardment. Bombardment is a newer technique and is less familiar to a number of labs. Here we describe a simple protocol to generate transgenic worms by biolistic bombardment with gold particles using the Bio-Rad PDS-1000 system. Compared with DNA microinjection into hermaphrodite germline, this protocol has the advantage of not requiring special skills from the operator with regards to identifying worm anatomy or performing microinjection. Further multiple transgenic lines are usually obtained from a single bombardment. Also in contrast to microinjection, biolistic bombardment produces transgenic animals with both extrachromosomal arrays and integrated transgenes. The ability to obtain integrated transgenic lines can avoid the use of mutagenic protocols to integrate foreign DNA. In conclusion, biolistic bombardment can be an attractive method for the generation of transgenic animals, especially for investigators not interested in investing the time and effort needed to become skilled at microinjection.

Hochbaum, Daniel; Ferguson, Annabel A.; Fisher, Alfred L.

2010-01-01

266

A transgenic apple callus showing reduced polyphenol oxidase activity and lower browning potential.  

PubMed

Polyphenol oxidase (PPO) is responsible for enzymatic browning of apples. Apples lacking PPO activity might be useful not only for the food industry but also for studies of the metabolism of polyphenols and the function of PPO. Transgenic apple calli were prepared by using Agrobacterium tumefaciens carrying the kanamycin (KM) resistant gene and antisense PPO gene. Four KM-resistant callus lines were obtained from 356 leaf explants. Among these transgenic calli, three calli grew on the medium containing KM at the same rate as non-transgenic callus on the medium without KM. One callus line had an antisense PPO gene, in which the amount and activity of PPO were reduced to half the amount and activity in non-transgenic callus. The browning potential of this line, which was estimated by adding chlorogenic acid, was also half the browning potential of non-transgenic callus. PMID:11302173

Murata, M; Nishimura, M; Murai, N; Haruta, M; Homma, S; Itoh, Y

2001-02-01

267

Determination of T 1? values for head and neck tissues at 0.1 T: a comparison to T 1 and T 2 relaxation times  

Microsoft Academic Search

In order to optimize head and neck magnetic resonance (MR) imaging with the spin-lock (SL) technique, the T1? relaxation times for normal tissues were determined. Furthermore, T1? was compared to T1 and T2 relaxation times. Ten healthy volunteers were studied with a 0.1 T clinical MR imager. T1? values were determined by first measuring the tissue signal intensities with different

Antti T Markkola; Hannu J Aronen; Usama Abo Ramadan; Juha T Halavaara; Jukka I Tanttu; Raimo E Sepponen

1998-01-01

268

Mammalian MagT1 and TUSC3 are required for cellular magnesium uptake and vertebrate embryonic development  

PubMed Central

Magnesium (Mg2+) is the second most abundant cation in cells, yet relatively few mechanisms have been identified that regulate cellular levels of this ion. The most clearly identified Mg2+ transporters are in bacteria and yeast. Here, we use a yeast complementary screen to identify two mammalian genes, MagT1 and TUSC3, as major mechanisms of Mg2+ influx. MagT1 is universally expressed in all human tissues and its expression level is up-regulated in low extracellular Mg2+. Knockdown of either MagT1 or TUSC3 protein significantly lowers the total and free intracellular Mg2+ concentrations in mammalian cell lines. Morpholino knockdown of MagT1 and TUSC3 protein expression in zebrafish embryos results in early developmental arrest; excess Mg2+ or supplementation with mammalian mRNAs can rescue the effects. We conclude that MagT1 and TUSC3 are indispensable members of the vertebrate plasma membrane Mg2+ transport system.

Zhou, Hao; Clapham, David E.

2009-01-01

269

Expression proteomics identifies biochemical adaptations and defense responses in transgenic plants with perturbed polyamine metabolism  

Microsoft Academic Search

Soluble proteins from leaves of transgenic tobacco plants with perturbed polyamine metabolism, caused by S-adenosylmethionine decarboxylase overexpression, were analysed by comparative proteomics. A group of proteins was found to be increasingly repressed, in parallel with the degree of polyamine perturbation, in each of the three independent transgenic lines. These were identified as isoforms of chloroplast ribonucleoproteins, known to be involved

Marina Franceschetti; Barry Perry; Benjamin Thompson; Colin Hanfrey; Anthony J. Michael

2004-01-01

270

Expression of Lysostaphin in Milk of Transgenic Mice Affects the Growth of Neonates  

Microsoft Academic Search

As an initial step towards enhancing mastitis resistance in dairy animals, we generated BLG-Lys transgenic mice that secrete lysostaphin, a potent antistaphylococcal protein, in their milk. In the current study, we continue our assessment of lysostaphin as a suitable antimicrobial protein for mastitis resistance and have investigated mammary gland development and function in three lines of transgenic mice. As the

Abhijit Mitra; Kathleen S. Hruska; Olga Wellnitz; David E. Kerr; Anthony V. Capuco; Robert J. Wall

2003-01-01

271

Imaging Neuronal Subsets in Transgenic Mice Expressing Multiple Spectral Variants of GFP  

Microsoft Academic Search

We generated transgenic mice in which red, green, yellow, or cyan fluorescent proteins (together termed XFPs) were selectively expressed in neurons. All four XFPs labeled neurons in their entirety, including axons, nerve terminals, dendrites, and dendritic spines. Remarkably, each of 25 independently generated transgenic lines expressed XFP in a unique pattern, even though all incorporated identical regulatory elements (from the

Guoping Feng; Rebecca H. Mellor; Michael Bernstein; Cynthia Keller-Peck; Quyen T. Nguyen; Mia Wallace; Jeanne M. Nerbonne; Jeff W. Lichtman; Joshua R. Sanes

2000-01-01

272

From the Cover: Transgenic Hydra allow in vivo tracking of individual stem cells during morphogenesis  

Microsoft Academic Search

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

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

2006-01-01

273

Molecular Modeling of PepT1 — Towards a Structure  

Microsoft Academic Search

The proton-coupled uptake of di- and tri-peptides is the major route of dietary nitrogen absorption in the intestine and of\\u000a reabsorption of filtered protein in the kidney. In addition, the transporters involved, PepT1 (SLC15a1) and PepT2 (SLC15a2),\\u000a are responsible for the uptake and tissue distribution of a wide range of pharmaceutically important compounds, including\\u000a ?-lactam antibiotics, angiotensin-converting enzyme inhibitors, anti-cancer

D. Meredith; R. A. Price

2006-01-01

274

A 90-Day Dietary Toxicity Study of Genetically Modified Rice T1C-1 Expressing Cry1C Protein in Sprague Dawley Rats  

PubMed Central

In a 90-day study, Sprague Dawley rats were fed transgenic T1C-1 rice expressing Cry1C protein and were compared with rats fed non-transgenic parental rice Minghui 63 and rats fed a basal diet. No adverse effects on animal behavior or weight gain were observed during the study. Blood samples were collected and analyzed, and standard hematological and biochemical parameters were compared. A few of these parameters were found to be significantly different, but were within the normal reference intervals for rats of this breed and age, and were thus not considered to be treatment-related. Following sacrifice, a large number of organs were weighed, and macroscopic and histopathological examinations were performed with no changes reported. The aim of this study was to use a known animal model to determine the safety of the genetically modified (GM) rice T1C-1. The results showed no adverse or toxic effects due to T1C-1 rice when tested in this 90-day study.

Tang, Xueming; Han, Fangting; Zhao, Kai; Xu, Yan; Wu, Xiao; Wang, Jinbin; Jiang, Lingxi; Shi, Wei

2012-01-01

275

Development of transgenic watermelon resistant to Cucumber mosaic virus and Watermelon mosaic virus by using a single chimeric transgene construct.  

PubMed

Watermelon, an important fruit crop worldwide, is prone to attack by several viruses that often results in destructive yield loss. To develop a transgenic watermelon resistant to multiple virus infection, a single chimeric transgene comprising a silencer DNA from the partial N gene of Watermelon silver mottle virus (WSMoV) fused to the partial coat protein (CP) gene sequences of Cucumber mosaic virus (CMV), Cucumber green mottle mosaic virus (CGMMV) and Watermelon mosaic virus (WMV) was constructed and transformed into watermelon (cv. Feeling) via Agrobacterium-mediated transformation. Single or multiple transgene copies randomly inserted into various locations in the genome were confirmed by Southern blot analysis. Transgenic watermelon R(0) plants were individually challenged with CMV, CGMMV or WMV, or with a mixture of these three viruses for resistance evaluation. Two lines were identified to exhibit resistance to CMV, CGMMV, WMV individually, and a mixed inoculation of the three viruses. The R(1) progeny of the two resistant R(0) lines showed resistance to CMV and WMV, but not to CGMMV. Low level accumulation of transgene transcripts in resistant plants and small interfering (si) RNAs specific to CMV and WMV were readily detected in the resistant R(1) plants by northern blot analysis, indicating that the resistance was established via RNA-mediated post-transcriptional gene silencing (PTGS). Loss of the CGMMV CP-transgene fragment in R1 progeny might be the reason for the failure to resistant CGMMV infection, as shown by the absence of a hybridization signal and no detectable siRNA specific to CGMMV in Southern and northern blot analyses. In summary, this study demonstrated that fusion of different viral CP gene fragments in transgenic watermelon contributed to multiple virus resistance via PTGS. The construct and resistant watermelon lines developed in this study could be used in a watermelon breeding program for resistance to multiple viruses. PMID:22203520

Lin, Ching-Yi; Ku, Hsin-Mei; Chiang, Yi-Hua; Ho, Hsiu-Yin; Yu, Tsong-Ann; Jan, Fuh-Jyh

2011-12-28

276

The magnetic field dependence of water T1 in tissues.  

PubMed

The magnetic field dependence of the composite (1)H(2)O nuclear magnetic resonance signal T(1) was measured for excised samples of rat liver, muscle, and kidney over the field range from 0.7 to 7 T (35-300 MHz) with a nuclear magnetic resonance spectrometer using sample-shuttle methods. Based on extensive measurements on simpler component systems, the magnetic field dependence of T(1) of all tissues studied are readily fitted at Larmor frequencies above 1 MHz with a simple relaxation equation consisting of three contributions: a power law, A*?(-0.60) related to the interaction of water with long-lived-protein binding sites, a logarithmic term B*?(d) *log(1+1/(??(d))(2)) related to water diffusion at macromolecular interfacial regions, and a constant term associated with the high frequency limit of water-spin-lattice relaxation. The parameters A and B include the concentration and surface area dependences respectively. The logarithmic diffusion term becomes significant at high magnetic fields and is consistent with rapid translational dynamics at macromolecular surfaces. The data are fitted well with translational correlation times of approximately 15 ps for human brain white matter, but with a B value three times larger than gray matter tissues. This analysis suggests that the water-surface translational correlation time is approximately three times longer than in gray matter. PMID:22144333

Diakova, Galina; Korb, Jean-Pierre; Bryant, Robert G

2011-12-05

277

Peptide transporter substrate identification during permeability screening in drug discovery: Comparison of transfected MDCK-hPepT1 cells to caco-2 cells  

Microsoft Academic Search

The purpose of this study was to investigate the utility of stably transfected MDCK-hPepT1 cells for identifying peptide transporter\\u000a substrates in early drug discovery and compare the characteristics of this cell line with Caco-2 cells. MDCK-hPepT1, MDCK-mock,\\u000a and Caco-2 cells grown to confluence on 24-well Transwell were used for this study. Expression levels of different transporter\\u000a proteins (PepT1, PepT2, P-gp)

Praveen V. Balimane; Saeho Chong; Karishma Patel; Yong Quan; Julita Timoszyk; Yong-Hae Han; Bonnie Wang; Balvinder Vig; Teresa N. Faria

2007-01-01

278

4-Tert-Octylphenol Regulates the Differentiation of C3H10T1\\/2 Cells into Osteoblast and Adipocyte Lineages  

Microsoft Academic Search

The aim of this study was to investigate whether 4-tert- octylphenol (OP) affects the differentiation of multipotent C3H10T1\\/2 cells, a cell line established from mouse embryonic connective tissue, into osteoblast and adipocyte lineages. Conflu- ent C3H10T1\\/2 cells were incubated for 7 days with (OP-treated cultures) or without (control cultures) 15 mg\\/ml of OP. The 7-day treatment of confluent cells with

Joji Miyawaki; Setsuya Kamei; Kenshi Sakayama; Haruyasu Yamamoto; Hiroshi Masuno

2007-01-01

279

Establishing a colony for efficient production of transgenic mice.  

PubMed

A specific and dedicated mouse colony is required if transgenic mice are to be efficiently produced. The structure of such a colony is described in the present chapter. Although the provision of these animal facilities will not present a problem to large research establishments, smaller laboratories must weigh the commitment of animal housing and maintenance against the extent of the proposed transgenic experiment and consider whether a collaboration with an established transgenic unit may best suit their purposes. In addition to the "production-line" mice, a transgenic facility must be able to accommodate large numbers of transgenics under analysis, possibly of multiple lines and generations. Time-consuming husbandry is required, which will involve both scientific and animal house staff. On deciding to establish a new transgenic unit, investigators must therefore ensure that junior scientific staff are prepared to take on extensive animal work-work that begins when the transgenics have been made. Staff with no animal experience must be trained by skilled animal-care operatives and should continue to seek advice at all times. There is no substitute for direct training, but novice workers may refer to manuals, for example. Prior to starting animal work, staff must consult appropriate government offices that regulate research animal use and obtain any necessary documentation. Even in countries where animal use is not monitored, it is essential that recognized standards of welfare and hygiene are maintained. With regard to animal health requirements, facilities need not conform to Specific Pathogen-Free (SPF) standards, but minimal precautions against infection should be taken. For example, entry to the facility should be restricted to essential staff only, who should wear fresh protective garments and gloves. The specific mouse population described here is commonly used in many transgenic units and should be adequate for three microinjection sessions per week. F2 zygotes, although less readily available, are chosen for microinjection, since the generation of transgenics and maintenance of lines is more efficient compared with inbred mice. Particular inbred lines must, of course, be used where a defined genetic background is a requirement of the experiment. PMID:21390652

Carter, D A

1993-01-01

280

Transgenic mice secreting coronavirus neutralizing antibodies into the milk.  

PubMed

Ten lines of transgenic mice secreting transmissible gastroenteritis coronavirus (TGEV) neutralizing recombinant monoclonal antibodies (rMAbs) into the milk were generated. The rMAb light- and heavy-chain genes were assembled by fusing the genes encoding the variable modules of the murine MAb 6A.C3, which binds an interspecies conserved coronavirus epitope essential for virus infectivity, and a constant module from a porcine myeloma with the immunoglobulin A (IgA) isotype. The chimeric antibody led to dimer formation in the presence of J chain. The neutralization specific activity of the recombinant antibody produced in transiently or stably transformed cells was 50-fold higher than that of a monomeric rMAb with the IgG1 isotype and an identical binding site. This rMAb had titers of up to 10(4) by radioimmunoassay (RIA) and neutralized virus infectivity up to 10(4)-fold. Of 23 transgenic mice, 17 integrated both light and heavy chains, and at least 10 of them transmitted both genes to the progeny, leading to 100% of animals secreting functional TGEV neutralizing antibody during lactation. Selected mice produced milk with TGEV-specific antibody titers higher than 10(6) as determined by RIA, neutralized virus infectivity by 10(6)-fold, and produced up to 6 mg of antibody per ml. Antibody expression levels were transgene copy number independent and integration site dependent. Comicroinjection of the genomic beta-lactoglobulin gene with rMAb light- and heavy-chain genes led to the generation of transgenic mice carrying the three transgenes. The highest antibody titers were produced by transgenic mice that had integrated the antibody and beta-lactoglobulin genes, although the number of transgenic animals generated does not allow a definitive conclusion on the enhancing effect of beta-lactoglobulin cointegration. This approach may lead to the generation of transgenic animals providing lactogenic immunity to their progeny against enteric pathogens. PMID:9557658

Sola, I; Castilla, J; Pintado, B; Sánchez-Morgado, J M; Whitelaw, C B; Clark, A J; Enjuanes, L

1998-05-01

281

Consistent and stable expression of the npt II, uid A and bar genes in transgenic Pinus radiata after Agrobacterium tumefaciens -mediated transformation using nurse cultures  

Microsoft Academic Search

An Agrobacterium tumefaciens-mediated transformation protocol has been developed for embryogenic cell cultures of Pinus radiata. Transgenic lines were only produced when embryogenic tissue was placed on nurse tissue during the Agrobacterium co-cultivation and recovery stages of the procedure. Plantlets were regenerated via somatic embryogenesis from ten of the 11 transgenic lines tested and at least 20 of each line were

J. A. Charity; L. Holland; L. J. Grace; C. Walter

2005-01-01

282

[Enhanced biosynthesis of scopolamine in transgenic Atropa belladonna by overexpression of h6h gene].  

PubMed

Transgenic Atropa belladonna with high levels of scopolamine was developed by metabolic engineering. A functional gene involved in the rate limiting enzyme of h6h involved in the biosynthetic pathway of scopolamine was over expressed in A. belladonna via Agrobacterium-mediation. The transgenic plants were culturing till fruiting through micropropogating and acclimating. The integration of the h6h genes into the genomic DNA of transgenic plants were confirmed by genomic polymerase chain reaction (PCR) analysis. Analysis of the difference of plant height, crown width, stem diameter, leaf length, leaf width, branch number and fresh weight was carried out using SPSS software. The content of hyoscyamine and scopolamine in roots, stems, leaves and fruits was determined by HPLC. The investigation of the expression levels of Hnh6h by qPCR. Both Kan(r) and Hnh6h genes were detected in five transgenic lines of A. belladonna plants (A8, A11, A12, C8 and C19), but were not detected in the controls. The plant height, crown width, stem diameter, leaf length, leaf width, branch number and fresh weight of transgenic plants did not decrease by comparison with the non-transgenic ones, and furthermore some agronomic characters of transgenic plants were better than those of the controls. The highest level of scopolamine was found in leaves of transgenic A. belladonna, and the content of scopolamine was also higher than that of hyoscyamine in leaves. The contents of scopolamine of leaves in different transgenic lines were listed in order: C8 > A12 > C19 > A11 > A8, especially, the content of scopolamine in transgenic line C8 was 2.17 mg x g(-1) DW that was 4.2 folds of the non-transgenic ones (0.42 mg x g(-1) DW). The expression of transgenic Hnh6h was detected in all the transgenic plants but not in the control. The highest level of Hnh6h expression was found in transgenic leaves. Overexpression of Hnh6h is able to break the rate limiting steps involved in the downstream pathway of scopolamine biosynthesis, and thus promotes the metabolic flux flowing toward biosynthesis of scopolamine to improve the capacity of scopolamine biosynthesis in transgenic plants. As a result, transgenic plants of A. belladonna with higher level of scopolamine were developed. PMID:24010284

Li, Jin-Di; Qin, Bai-Fu; Yang, Chun-Xian; Lan, Xiao-Zhong; Wu, Neng-Biao; Liao, Zhi-Hua

2013-06-01

283

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

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

1966-01-01

284

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

Microsoft Academic Search

Huntington's disease (HD) is a fatal inherited neurodegenerative disorder characterized by personality changes, motor impairment, and subcortical dementia. HD is one of a number of diseases caused by expression of an expanded polyglutamine repeat. We have developed several lines of mice that are transgenic for exon 1 of the HD gene containing an expanded CAG sequence. These mice exhibit a

Mark Turmaine; Aysha Raza; Amarbirpal Mahal; Laura Mangiarini; Gillian P. Bates; Stephen W. Davies

2000-01-01

285

GAA repeat instability in Friedreich ataxia YAC transgenic mice  

Microsoft Academic Search

Friedreich ataxia (FRDA) is primarily caused by an unstable GAA repeat-expansion mutation within intron 1 of the FRDA gene. However, the exact mechanisms leading to this expansion and its consequences are not fully understood. To study the dynamics of this mutation, we have generated two lines of human FRDA YAC transgenic mice that contain GAA repeat expansions within the appropriate

Sahar Al-Mahdawi; Ricardo Mouro Pinto; Piers Ruddle; Christopher Carroll; Zoe Webster; Mark Pook

2004-01-01

286

Transgenic Mouse Models of Lipoprotein Metabolism and Atherosclerosis  

Microsoft Academic Search

Lipoprotein transport genes have either been added to the germ line of mice by transgenic techniques or knocked out by homologous recombination in embryonic stem cells. The resultant over- or underexpression of these genes has resulted in new insights about how these genes function in the body and their role in lipoprotein metabolism. Either singly or in combination, these genetic

Jan L. Breslow

1993-01-01

287

TRANSGENIC FOOD ANIMALS FOR AUSTRALIA AND NEW ZEALAND  

Microsoft Academic Search

The transfer of DNA into the germ-line is central to the production of a transgenic animal, requiring transport of a DNA construct across cellular and nuclear membranes, and insertion into the genome of a multipotent cell. Several approaches have been taken to mediate this transport. The original and most common method is micro-injection of DNA into a newly fertilised zygote.

R. B. SEYMOUR; R. E. LYONS; A. BROWNLEE; P. LEDWITH; G. S. HARPER

288

DISEASE RESISTANT TRANSGENIC COTTON TO PREVENT PREHARVEST AFLATOXIN CONTAMINATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

We are developing transgenic cottons that are resistant to the saprophytic fungus Aspergillus flavus, which produces carcinogenic aflatoxin on lipid-rich cottonseed. Several independently transformed lines of cotton expressing antifungal genes coding for either the chloroperoxidase (CPO-P) or the s...

289

Targeting of glutamine synthetase to the mitochondria of transgenic tabacco  

Microsoft Academic Search

Two transgenic tobacco lines were genetically engineered to contain chimaeric genes encoding the glutamine synthetase (GS) ? polypeptide of Phaseolus vulgaris (French bean), expressed from the cauliflower mosaic virus 35S promoter. One (MIT-1) contained two copies of a construct including the first 60 amino acids of the Nicotiana plumbaginifolia ß-F1 ATPase to target the GS polypeptide to the mitochondrion. The

Pascale Hemon; Mark P. Robbins; Julie V. Cullimore

1990-01-01

290

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

291

Real-time PCR for the detection of precise transgene copy number in durum wheat.  

PubMed

Recent results obtained in various crops indicate that real-time PCR could be a powerful tool for the detection and characterization of transgene locus structures. The determination of transgenic locus number through real-time PCR overcomes the problems linked to phenotypic segregation analysis (i.e. lack of detectable expression even when the transgenes are present) and can analyse hundreds of samples in a day, making it an efficient method for estimating gene copy number. Despite these advantages, many authors speak of "estimating" copy number by real-time PCR, and this is because the detection of a precise number of transgene depends on how well real-time PCR performs.This study was conducted to determine transgene copy number in transgenic wheat lines and to investigate potential variability in sensitivity and resolution of real-time chemistry by TaqMan probes. We have applied real-time PCR to a set of four transgenic durum wheat lines previously obtained. A total of 24 experiments (three experiments for two genes in each transgenic line) were conducted and standard curves were obtained from serial dilutions of the plasmids containing the genes of interest. The correlation coefficients ranged from 0.95 to 0.97. By using TaqMan quantitative real-time PCR we were able to detect 1 to 41 copies of transgenes per haploid genome in the DNA of homozygous T4 transformants. Although a slight variability was observed among PCR experiments, in our study we found real-time PCR to be a fast, sensitive and reliable method for the detection of transgene copy number in durum wheat, and a useful adjunct to Southern blot and FISH analyses to detect the presence of transgenic DNA in plant material. PMID:21922222

Gadaleta, Agata; Giancaspro, Angelica; Cardone, Maria Francesca; Blanco, Antonio

2011-09-15

292

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.

Schafer, Tina; Hanke, Magda-Viola; Flachowsky, Henryk; Konig, Stephan; Peil, Andreas; Kaldorf, Michael; Polle, Andrea; Buscot, Francois

2012-01-01

293

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

PubMed

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

2012-06-23

294

The Human Papillomavirus Type 8 E2 Protein Induces Skin Tumors in Transgenic Mice  

Microsoft Academic Search

Transgenic mice expressing early genes of the cutaneous human papillomavirus 8 (HPV8) spontaneously develop skin papillomas, epidermal dysplasia, and squamous cell carcinoma (6%). As the HPV8 protein E2 revealed transforming capacity in vitro, we generated three epidermal specific HPV8-E2-transgenic FVB\\/N mouse lines to dissect its role in tumor development. The rate of tumor formation in the three lines correlated with

Regina Pfefferle; Gian Paolo Marcuzzi; Baki Akgül; Hans Udo Kasper; Falko Schulze; Ingo Haase; Claudia Wickenhauser; Herbert Pfister

2008-01-01

295

Fecundity and life span in transgenic Drosophila melanogaster overexpressing hsp70  

Microsoft Academic Search

In the present study, we investigated the effect of hsp70 over expression on some life history components in transgenic fruit\\u000a flies. We measured life span in mated flies and fecundity in flies subjected or not subjected to a heat shock inducing hsp70.\\u000a Heat shock increased life span of the parental line, but not of the transgenic lines. Genetic manipulation of

Nadčge Minois; Sofia Vaynberg

2002-01-01

296

Enhanced expression and stable transmission of transgenes flanked by inverted terminal repeats from adeno-associated virus in zebrafish.  

PubMed

Mosaic expression of transgenes in the F0 generation severely hinders the study of transient expression in transgenic fish. To avoid mosaicism, enhanced green fluorescent protein (EGFP) gene cassettes were constructed and introduced into one-celled zebrafish embryos. These EGFP gene cassettes were flanked by inverted terminal repeats (ITRs) from adeno-associated virus (AAV) and driven by zebrafish alpha-actin (palpha-actin-EGFP-ITR) or medaka beta-actin promoters (pbeta-actin-EGFP-ITR). EGFP was expressed specifically and uniformly in the skeletal muscle of 56% +/- 8% of the palpha-actin-EGFP-ITR-injected survivors and in the entire body of 1.3% +/- 0.8% of the pbeta-actin-EGFP-ITR-injected survivors. Uniform transient expression never occurred in zebrafish embryos injected with EGFP genes that were not flanked by AAV-ITRs. In the F0 generation, uniformly distributed EGFP could mimic the stable expression in transgenic lines early in development. We established five transgenic lines derived from palpha-actin-EGFP-ITR-injected embryos crossed with wild-type fish and 11 transgenic lines derived from pbeta-actin-EGFP-ITR-injected embryos crossed with wild-type fish. None of these transgenic lines failed to express the transgene, a result confirmed by polymerase chain reaction analysis. Stable mendelian transmission of the transgenes was achieved in both alpha-actin and beta-actin transgenic lines without changing the patterns of expression and integration. Progeny inheritance test and Southern blot analysis results strongly suggest that transgenes flanked by AAV-ITRs were integrated randomly into the genome at a single locus with a concatamerized multiplier. Thus, incorporating AAV-ITRs into transgenes results in uniform gene expression in the F0 generation and stable transmission of transgenes in zebrafish. PMID:11307166

Hsiao, C D; Hsieh, F J; Tsai, H J

2001-04-01

297

Transgenic engineering of male-specific muscular hypertrophy  

Microsoft Academic Search

Using a two-step procedure involving insertional gene targeting and recombinase-mediated cassette exchange in ES cells, we have produced two lines of transgenic mice expressing a dominant-negative latency-associated myostatin propeptide under control of the myosin light chain 1F promoter and 1\\/3 enhancer from the TSPY locus on the Y chromosome. Males of the corresponding lines are characterized by a 5-20% increase

Dimitri Pirottin; Luc Grobet; Antoine Adamantidis; Frédéric Farnir; Christian Herens; Henrik Daa Schrřder; Michel Georges

2005-01-01

298

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.

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

2010-01-01

299

Post-mortem re-cloning of a transgenic red fluorescent protein dog  

PubMed Central

Recently, the world's first transgenic dogs were produced by somatic cell nuclear transfer. However, cellular senescence is a major limiting factor for producing more advanced transgenic dogs. To overcome this obstacle, we rejuvenated transgenic cells using a re-cloning technique. Fibroblasts from post-mortem red fluorescent protein (RFP) dog were reconstructed with in vivo matured oocytes and transferred into 10 surrogate dogs. One puppy was produced and confirmed as a re-cloned dog. Although the puppy was lost during birth, we successfully established a rejuvenated fibroblast cell line from this animal. The cell line was found to stably express RFP and is ready for additional genetic modification.

Hong, So Gun; Koo, Ok Jae; Oh, Hyun Ju; Park, Jung Eun; Kim, Minjung; Kim, Geon-A; Park, Eun Jung; Jang, Goo

2011-01-01

300

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

PubMed

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

2013-03-06

301

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.

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

2013-01-01

302

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.

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

2004-01-01

303

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

2004-09-07

304

T1 colorectal cancer with synchronous liver metastasis.  

PubMed

The patient was a 68-year-old man who was admitted to our hospital with a liver tumor. Abdominal ultrasonography and computed tomography revealed a liver tumor 30 mm in diameter. On colonoscopy, a pedunculated tumor with a central depression (20 mm in diameter) was observed in the ascending colon, and this tumor was considered to be invading deeply into the submucosal layer. Right hemicolectomy with D3 lymphadenectomy and partial hepatectomy were performed simultaneously. On histopathological examination of the resected specimen, the tumor was a well-differentiated tubular adenocarcinoma with 3,000 ?m invasion of the submucosal layer. The liver tumor showed histological findings similar to those of the primary colorectal carcinoma. The pathological stage according to the 7th edition of the TNM classification was stage IV (T1N0M1). Nine months after the operation, computed tomography revealed hepatic hilar lymph node metastases and a great deal of ascites. The patient ultimately died 14 months after the operation. PMID:23898232

Sugimoto, Kiichi; Kawai, Masaya; Takehara, Kazuhiro; Tashiro, Yoshihiko; Munakata, Shinya; Ishiyama, Shun; Komiyama, Hiromitsu; Takahashi, Makoto; Kojima, Yutaka; Goto, Michitoshi; Tomiki, Yuichi; Sakamoto, Kazuhiro; Kawasaki, Seiji

2013-06-22

305

T1 Colorectal Cancer with Synchronous Liver Metastasis  

PubMed Central

The patient was a 68-year-old man who was admitted to our hospital with a liver tumor. Abdominal ultrasonography and computed tomography revealed a liver tumor 30 mm in diameter. On colonoscopy, a pedunculated tumor with a central depression (20 mm in diameter) was observed in the ascending colon, and this tumor was considered to be invading deeply into the submucosal layer. Right hemicolectomy with D3 lymphadenectomy and partial hepatectomy were performed simultaneously. On histopathological examination of the resected specimen, the tumor was a well-differentiated tubular adenocarcinoma with 3,000 ?m invasion of the submucosal layer. The liver tumor showed histological findings similar to those of the primary colorectal carcinoma. The pathological stage according to the 7th edition of the TNM classification was stage IV (T1N0M1). Nine months after the operation, computed tomography revealed hepatic hilar lymph node metastases and a great deal of ascites. The patient ultimately died 14 months after the operation.

Sugimoto, Kiichi; Kawai, Masaya; Takehara, Kazuhiro; Tashiro, Yoshihiko; Munakata, Shinya; Ishiyama, Shun; Komiyama, Hiromitsu; Takahashi, Makoto; Kojima, Yutaka; Goto, Michitoshi; Tomiki, Yuichi; Sakamoto, Kazuhiro; Kawasaki, Seiji

2013-01-01

306

Tryptophan Conformations Associated with Partial Unfolding in Ribonuclease T1  

PubMed Central

The origin of the biexponential fluorescence decay of Trp in ribonuclease T1 under mildly destabilizing conditions, such as increased pH or temperature, or the presence of detergent, is still not understood. We have performed two extended replica-exchange molecular dynamics simulations to obtain a detailed representation of the native state at two protonation states corresponding to a high and low pH. At high pH, the appearance of partially unfolded states is evident. We found that this pH-induced destabilization originates from increased global repulsion as well as reduced local favorable electrostatic interactions and reduced H-bonding strength of His27, His40, and His92. At high pH, alternative tryptophan rotamers appear and are linked to a distorted environment of the tryptophan, which also acts as a separate source of ground-state heterogeneity. The total population of these alternative conformations agrees well with the amplitude of the experimentally observed secondary fluorescence lifetime.

Moors, Samuel L.C.; Jonckheer, Abel; De Maeyer, Marc; Engelborghs, Yves; Ceulemans, Arnout

2009-01-01

307

Antisense apple ACC-oxidase RNA reduces ethylene production in transgenic tomato fruit  

Microsoft Academic Search

Transgenic tomato (Lycopersicon esculentum) plants were produced which expressed antisense copies of an apple fruit ACC-oxidase RNA. In the fruit of the primary transformants, ethylene production was reduced by over 95% in one of the lines assessed, and to a lesser extent in the other lines. The line showing the greatest reduction in ethylene production showed a delay in the

Karen M. Bolitho; Michael Lay-Yee; Michelle L. Knighton; Gavin S. Ross

1997-01-01

308

Comparison of MR images for age determination; T1 weighted images (T1WI) versus T2* weighted images (T2*WI)  

PubMed Central

Purpose T1WI (T1 weighted image) was acquired in order to grade bone fusion following the studies by FIFA (Federation Internationale de Football Associations). Research using images other than T1WI has not been reported. The aim of this study is to evaluate the grade of epiphyseal fusion by T2* weighted images (T2*WI) and to investigate new findings on T2*WI as compared with T1WI. Methods A total of 87 subjects, all junior football players between the ages of 12 and 17 years old, were examined. T1 and T2* WI were obtained using a 1.2T Open type MR system. The T1WI and T2*WI were rated twice randomly by four radiologists using the FIFA grading system. Results The intra-rater reliability for grading was higher in T1WI (The Intraclass Correlation Coefficient (ICC)=0.949–0.985) than in T2*WI (ICC=0.917–0.943). The inter-rater reliability for grading was also higher in T1WI (ICC=0.923) than in T2*WI (ICC=0.867). Conclusions This research showed that T1WI is a better sequence than T2*WI to evaluate bone fusion following FIFA protocol. It was speculated that the reason for this is that T1WI has higher tissue contrast resolution and enables clearer images of the epiphyseal fusion than T2*WI and the grading system by T1WI was not suitable for T2*WI.

Shimada, Yoshikazu; Shimao, Daisuke; Kobayashi, Jiro; Nakahori, Chikako; Shimada, Mariko; Fujimoto, Hiroo; Misawa, Tatsuya; Kato, Haruyasu; Dohi, Michiko

2012-01-01

309

Sensing of amino acids by the gut-expressed taste receptor T1R1-T1R3 stimulates CCK secretion.  

PubMed

CCK is secreted by endocrine cells of the proximal intestine in response to dietary components, including amino acids. CCK plays a variety of roles in digestive processes, including inhibition of food intake, consistent with a role in satiety. In the lingual epithelium, the sensing of a broad spectrum of L-amino acids is accomplished by the heteromeric amino acid (umami) taste receptor (T1R1-T1R3). T1R1 and T1R3 subunits are also expressed in the intestine. A defining characteristic of umami sensing by T1R1-T1R3 is its potentiation by IMP or GMP. Furthermore, T1R1-T1R3 is not activated by Trp. We show here that, in response to L-amino acids (Phe, Leu, Glu, and Trp), but not D-amino acids, STC-1 enteroendocrine cells and mouse proximal small intestinal tissue explants secrete CCK and that IMP enhances Phe-, Leu-, and Glu-induced, but not Trp-induced, CCK secretion. Furthermore, small interfering RNA inhibition of T1R1 expression in STC-1 cells results in significant diminution of Phe-, Leu-, and Glu-stimulated, but not Trp-stimulated, CCK release. In STC-1 cells and mouse intestine, gurmarin inhibits Phe-, Leu-, and Glu-induced, but not Trp-stimulated, CCK secretion. In contrast, the Ca(2+)-sensing receptor antagonist NPS2143 inhibits Phe-stimulated CCK release partially and Trp-induced CCK secretion totally in mouse intestine. However, NPS2143 has no effect on Leu- or Glu-induced CCK secretion. Collectively, our data demonstrate that functional characteristics and cellular location of the gut-expressed T1R1-T1R3 support its role as a luminal sensor for Phe-, Leu-, and Glu-induced CCK secretion. PMID:23203156

Daly, Kristian; Al-Rammahi, Miran; Moran, Andrew; Marcello, Marco; Ninomiya, Yuzo; Shirazi-Beechey, Soraya P

2012-11-29

310

Induction of apoptosis in the LNCaP human prostate carcinoma cell line and prostate adenocarcinomas of SV40T antigen transgenic rats by the Bowman-Birk inhibitor.  

PubMed

The soybean-derived serine protease inhibitor, Bowman-Birk inhibitor (BBI), has been reported as a potent chemoprevention agent against several types of tumors. The present study was undertaken to evaluate the effects of BBI on androgen-sensitive/dependent prostate cancers using a human prostate cancer cell (LNCaP) and the transgenic rats developing adenocarcinoma of the prostate (TRAP) model. Treatment of LNCaP prostate cancer cells with 500 microg/mL BBI resulted in inhibition of viability measured on WST-1 assays, with induction of connexin 43 (Cx43) and cleaved caspase-3 protein expression. Feeding of 3% roughly prepared BBI (BBIC) to TRAP from the age 3 weeks to 13 weeks resulted in significant reduction of the relative epithelial areas within the acinus and multiplicity of the adenocarcinomas in the lateral prostate lobes. Cx43- and terminal deoxynucleotidyl transferase mediated dUTP-biotin end labeling of fragmented DNA (TUNEL)-positive apoptotic cancer cells were more frequently observed in the lateral prostates treated with BBIC than in the controls. These in vivo and in vitro results suggest that BBI possesses chemopreventive activity associated with induction of Cx43 expression and apoptosis. PMID:19883429

Tang, MingXi; Asamoto, Makoto; Ogawa, Kumiko; Naiki-Ito, Aya; Sato, Shinya; Takahashi, Satoru; Shirai, Tomoyuki

2009-11-01

311

Trigger for group A streptococcal M1T1 invasive disease  

Microsoft Academic Search

The globally disseminated Streptococcus pyogenes M1T1 clone causes a number of highly invasive human diseases. The transition from local to systemic infection occurs by an unknown mechanism; however invasive M1T1 clinical isolates are known to express significantly less cysteine protease SpeB than M1T1 isolates from local infections. Here, we show that in comparison to the M1T1 strain 5448, the isogenic

Jason N. Cole; Jason D. McArthur; Fiona C. McKay; Martina L. Sanderson-Smith; Amanda J. Cork; Marie Ranson; Manfred Rohde; Andreas Itzek; Hongmin Sun; David Ginsburg; Malak Kotb; Victor Nizet; G. S. Chhatwal; Mark J. Walker

2006-01-01

312

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

2012-11-16

313

Eosinophil-Deficient Transgenic Animals.  

National Technical Information Service (NTIS)

The technologies described herein are based on the discovery that expression of a toxin gene under control of an eosinophil-specific promoter can cause the ablation of eosinophils in a transgenic animal. Accordingly, the nucleic acid constructs featured i...

J. J. Lee N. A. Lee

2004-01-01

314

Transgenic modeling of neuropsychiatric disorders.  

PubMed

Converging advances in the fields of molecular biology, molecular genetics, cellular biology and embryology have given researchers the tools for the targeted delivery and stable germline transmission of foreign genes (transgenes) in the mouse. In the realm of neuropsychiatry, this so-named transgenic technology has begun to catapult our knowledge of the genetic, molecular and cellular mechanisms in the brain that are linked to a variety of mental disorders as well as normal behavioral processes such as learning and memory. Moreover, the potential for transgenic technology to develop more precise animal models of specific human neuropsychiatric disorders will likely lead to the identification of novel targets for therapeutic intervention and facilitate the preclinical testing of new therapeutic agents. This article examines key issues and highlights recent developments pertaining to the transgenic modeling of neuropsychiatric disorders. PMID:9118320

Campbell, I L; Gold, L H

1996-05-01

315

Transgenic mice in developmental toxicology.  

National Technical Information Service (NTIS)

Advances in molecular biology and embryology are being utilized for the generation of transgenic mice, animals that contain specific additions, deletions, or modifications of genes or sequences in their DNA. Mouse embryonic stem cells and homologous recom...

R. P. Woychik

1992-01-01

316

Effects of transgenic fructan-producing potatoes on the community structure of rhizosphere and phyllosphere bacteria.  

PubMed

The rhizosphere and phyllosphere microbial communities of transgenic potatoes producing fructan were studied in comparison with isogenic controls and conventional varieties in a field release experiment over a period of 3 years. Population densities and 16S rRNA gene-based terminal restriction fragment length polymorphism (T-RFLP) analysis of the rhizosphere bacterial community only displayed the influence of annual and seasonal effects and the influence of field heterogeneity. In contrast, the T-RFLP analysis of the phyllosphere bacteria revealed in two of the 3 years significant differences in the community structure between the transgenic lines producing inulin and the other variants. This effect was studied in more detail through the analysis of bacterial isolates and a 16S rRNA gene clone library obtained from a transgenic line and the control. Both methods revealed a lower genetic diversity in the transgenic line and changes in the abundance of several bacterial groups. The isolates of the transgenic line were dominated by Bacilli, whereas most of the control isolates represented Actinobacteria. The clones were dominated by Proteobacteria, with main differences between both variants in Deltaproteobacteria, Bacilli and Bacteroidetes. However, all in all, the impact of the transgenic lines did not exceed the natural variability of the phyllosphere community structure on potato plants. PMID:18662310

Becker, Regina; Behrendt, Undine; Hommel, Bernd; Kropf, Siegfried; Ulrich, Andreas

2008-07-24

317

Gurmarin sensitivity of sweet taste responses is associated with co-expression patterns of T1r2, T1r3, and gustducin.  

PubMed

Gurmarin (Gur) is a peptide that selectively suppresses sweet taste responses in rodents. The inhibitory effect of Gur differs among tongue regions and mouse strains. Recent studies demonstrated that co-expression levels of genes controlling sweet receptors (T1r2/T1r3 heterodimer) versus Galpha-protein, gustducin, are much lower in Gur-insensitive posterior circumvallate papillae than in Gur-sensitive anterior fungiform papillae. Here, we investigated the potential link of Gur-sensitivity with the co-expression for T1r2/T1r3 receptors and gustducin by comparing those of taste tissues of Gur-sensitive (B6, dpa congenic strains) and Gur-weakly-sensitive (BALB) strains. The results indicated that co-expression ratios among T1r2, T1r3, and gustducin in the fungiform papillae were significantly lower in Gur-weakly-sensitive BALB mice than in Gur-sensitive B6 and dpa congenic mice. This linkage between Gur-sensitivity and co-expression for T1r2/T1r3 receptors versus gustducin suggests that gustducin may be a key molecule involved in the pathway for Gur-sensitive sweet responses. PMID:18174025

Shigemura, Noriatsu; Nakao, Kazuko; Yasuo, Toshiaki; Murata, Yoshihiro; Yasumatsu, Keiko; Nakashima, Akihiko; Katsukawa, Hideo; Sako, Noritaka; Ninomiya, Yuzo

2008-01-02

318

Heterology Expression of the Arabidopsis C-Repeat/Dehydration Response Element Binding Factor 1 Gene Confers Elevated Tolerance to Chilling and Oxidative Stresses in Transgenic Tomato1  

PubMed Central

In an attempt to improve stress tolerance of tomato (Lycopersicon esculentum) plants, an expression vector containing an Arabidopsis C-repeat/dehydration responsive element binding factor 1 (CBF1) cDNA driven by a cauliflower mosaic virus 35S promoter was transferred into tomato plants. Transgenic expression of CBF1 was proved by northern- and western-blot analyses. The degree of chilling tolerance of transgenic T1 and T2 plants was found to be significantly greater than that of wild-type tomato plants as measured by survival rate, chlorophyll fluorescence value, and radical elongation. The transgenic tomato plants exhibited patterns of growth retardation; however, they resumed normal growth after GA3 (gibberellic acid) treatment. More importantly, GA3-treated transgenic plants still exhibited a greater degree of chilling tolerance compared with wild-type plants. Subtractive hybridization was performed to isolate the responsive genes of heterologous Arabidopsis CBF1 in transgenic tomato plants. CATALASE1 (CAT1) was obtained and showed activation in transgenic tomato plants. The CAT1 gene and catalase activity were also highly induced in the transgenic tomato plants. The level of H2O2 in the transgenic plants was lower than that in the wild-type plants under either normal or cold conditions. The transgenic plants also exhibited considerable tolerance against oxidative damage induced by methyl viologen. Results from the current study suggest that heterologous CBF1 expression in transgenic tomato plants may induce several oxidative-stress responsive genes to protect from chilling stress.

Hsieh, Tsai-Hung; Lee, Jent-Turn; Yang, Pei-Tzu; Chiu, Li-Hui; Charng, Yee-yung; Wang, Yu-Chie; Chan, Ming-Tsair

2002-01-01

319

In vitro DNA methylation inhibits gene expression in transgenic tobacco.  

PubMed Central

A hemimethylated chimeric gene, containing the cauliflower mosaic virus 35S promoter, the beta-glucuronidase coding region and the polyadenylation signal of nopaline synthase, was introduced into tobacco protoplasts by polyethylene glycol mediated transfection. Hemimethylation led to complete inhibition of transient gene expression. In regenerated transgenic plants the integrated gene was constitutively hypermethylated at the sequences CpG and CpNpG and this was correlated with an inactivation of beta-glucuronidase in 12 out of 18 analyzed plant lines whereas two showed slight and four strong activity. From 10 control lines transformed with nonmethylated DNA, only two were inactive; three showed slight and five strong activity. 5-aza-cytidine treatment of plant tissue from 'hypermethylated' lines led to induction of beta-glucuronidase in most cases. Shoots regenerated from azaC treated calli revealed stable enzyme restoration and demethylation of the integrated transgene. Images Fig. 2. Fig. 4. Fig. 5.

Weber, H; Ziechmann, C; Graessmann, A

1990-01-01

320

Live imaging of transgenic mice expressing FRET biosensors.  

PubMed

In recent years, fluorescence imaging has received particular attention, due to increasing availabilities of fluorescent proteins and dyes, which had driven the development of novel biosensors. Genetically-encoded biosensors based on the principle of Förster resonance energy transfer (FRET) have been widely used in biology to visualize the spatiotemporal dynamics of signaling molecules. Despite the increasing multitude of these biosensors, their application has been mostly limited to cultured cells with transient biosensor expression, due to difficulties in stable expression of FRET biosensors. In this study, we report efficient generation of transgenic mouse lines expressing heritable and functional biosensors for ERK and PKA. These transgenic mice were generated by the cytoplasmic co-injection of Tol2 transposase mRNA and a circular plasmid harboring Tol2 recombination sites. Observation of these transgenic mice by two-photon excitation microscopy yielded real-time activity maps of ERK and PKA in various tissues, with greatly improved signal-to-background ratios. Our transgenic mice may be bred into diverse genetic backgrounds; moreover, the protocol we have developed paves the way for the generation of transgenic mice that express other FRET biosensors, with important applications in the characterization of physiological and pathological signal transduction events in addition to drug development and screening. PMID:24109640

Kamioka, Yuji; Sumiyama, Kenta; Mizuno, Rei; Matsuda, Michiyuki

2013-07-01

321

Transgenic cyclooxygenase-2 overexpression sensitizes mouse skin for carcinogenesis  

PubMed Central

Genetic and pharmacological evidence suggests that overexpression of cyclooxygenase-2 (COX-2) is critical for epithelial carcinogenesis and provides a major target for cancer chemoprevention by nonsteroidal antiinflammatory drugs. Transgenic mouse lines with keratin 5 promoter-driven COX-2 overexpression in basal epidermal cells exhibit a preneoplastic skin phenotype. As shown here, this phenotype depends on the level of COX-2 expression and COX-2-mediated prostaglandin accumulation. The transgenics did not develop skin tumors spontaneously but did so after a single application of an initiating dose of the carcinogen 7,12-dimethylbenz[a]anthracene (DMBA). Long-term treatment with the tumor promoter phorbol 12-myristate 13-acetate, as required for tumorigenesis in wild-type mice, was not necessary for transgenics. The ratios of squamous cell carcinomas to papillomas and of sebaceous gland adenomas to papillomas plus squamous cell carcinomas were increased markedly in transgenic mice treated with DMBA alone compared with DMBA/phorbol 12-myristate 13-acetate-treated transgenic and wild-type mice. Thus, COX-2 overexpression, which leads to high levels of epidermal prostaglandin E2, prostaglandin F2?, and 15-deoxy?12,14-PGJ2, is insufficient for tumor induction but transforms epidermis into an “autopromoted” state, i.e., dramatically sensitizes the tissue for genotoxic carcinogens.

Muller-Decker, Karin; Neufang, Gitta; Berger, Irina; Neumann, Melanie; Marks, Friedrich; Furstenberger, Gerhard

2002-01-01

322

Efficient discovery of ASCL1 regulatory sequences through transgene pooling  

PubMed Central

Zebrafish transgenesis is a powerful and increasingly common strategy to assay vertebrate transcriptional regulatory control. Several challenges remain, however, to the broader application of this technique; they include increasing the rate with which transgenes can be analyzed and maximizing the informational value of the data generated. Presently, many rely on the injection of individual constructs and the analysis of resulting reporter expression in mosaic G0 embryos. Here, we contrast these approaches, examining whether injecting pooled transgene constructs can increase the efficiency with which regulatory sequences can be assayed, restricting analysis to the offspring of germ line transmitting transgenic zebrafish in an effort to reduce potential subjectivity. We selected a 64 kb interval encompassing the human ASCL1 locus as our model interval and report the analysis of 9 highly conserved putative enhancers therein. We identified 32 transgene-positive zebrafish, transmitting one or more independent constructs displaying ASCL1-like regulatory control. Through examination of embryos harboring one or more transgenes, we demonstrate that five of the nine sequences account for the observed control and describe their likely roles in ASCL1 regulation. These data demonstrate the utility of this approach and its potential for further adaptation and higher throughput application.

McGaughey, David M.

2010-01-01

323

Correction with blood T1 is essential when measuring post-contrast myocardial T1 value in patients with acute myocardial infarction  

PubMed Central

Background Post-contrast T1 mapping by modified Look-Locker inversion recovery (MOLLI) sequence has been introduced as a promising means to assess an expansion of the extra-cellular space. However, T1 value in the myocardium can be affected by scanning time after bolus contrast injection. In this study, we investigated the changes of the T1 values according to multiple slicing over scanning time at 15 minutes after contrast injection and usefulness of blood T1 correction. Methods Eighteen reperfused acute myocardial infarction (AMI) patients, 13 cardiomyopathy patients and 8 healthy volunteers underwent cardiovascular magnetic resonance with 15 minute-post contrast MOLLI to generate T1 maps. In 10 cardiomyopathy cases, pre- and post-contrast MOLLI techniques were performed to generate extracellular volume fraction (Ve). Six slices of T1 maps according to the left ventricular (LV) short axis, from apex to base, were consecutively obtained. Each T1 value was measured in the whole myocardium, infarcted myocardium, non-infarcted myocardium and LV blood cavity. Results The mean T1 value of infarcted myocardium was significantly lower than that of non-infarcted myocardium (425.4±68.1 ms vs. 540.5±88.0 ms, respectively, p< 0.001). T1 values of non-infarcted myocardium increased significantly from apex to base (from 523.1±99.5 ms to 561.1±81.1 ms, p=0.001), and were accompanied by a similar increase in blood T1 value in LV cavity (from 442.1±120.7 ms to 456.8±97.5 ms, p<0.001) over time. This phenomenon was applied to both left anterior descending (LAD) territory (from 545.1±74.5 ms to 575.7±84.0 ms, p<0.001) and non-LAD territory AMI cases (from 501.2±124.5 ms to 549.5±81.3 ms, p<0.001). It was similarly applied to cardiomyopathy patients and healthy volunteers. After the myocardial T1 values, however, were adjusted by the blood T1 values, they were consistent throughout the slices from apex to base (from 1.17±0.18 to 1.25±0.13, p>0.05). The Ve did not show significant differences from apical to basal slices. Conclusion Post-contrast myocardial T1 corrected by blood T1 or Ve, provide more stable measurement of degree of fibrosis in non-infarcted myocardium in short- axis multiple slicing.

2013-01-01

324

Development of pulmonary bronchiolo-alveolar adenocarcinomas in transgenic mice overexpressing murine c-myc and epidermal growth factor in alveolar type II pneumocytes  

Microsoft Academic Search

Transgenic mouse models were established to study tumorigenesis of bronchiolo-alveolar adenocarcinomas derived from alveolar type II pneumocytes (AT-II cells). Transgenic lines expressing the murine oncogene c-myc under the control of the lung-specific surfactant protein C promoter developed multifocal bronchiolo-alveolar hyperplasias, adenomas and carcinomas respectively, whereas transgenic lines expressing a secretable form of the epidermal growth factor (IgEGF), a structural and

A Ehrhardt; T Bartels; A Geick; R Klocke; D Paul; R Halter

2001-01-01

325

In vitro pollen functionality of attacin-transgenic “Royal Gala” apple plants and apples transformed with 1-aminocyclopropane-1-carboxylic acid synthase (ACS)-antisense vector  

Microsoft Academic Search

To assess pollen functionality of transgenic apple trees, in vitro pollen germination and tube growth were evaluated. Flowers of transgenic “Royal Gala” apple lines containing attacin E gene to confer resistance to fire blight (Erwinia amylovora), or antisense 1-aminocyclopropane-1-carboxylic acid synthase (ACS) construct to improve fruit storage life, were collected, and pollen was harvested. Amongst the 19 transgenic lines, pollen from

K. Ko; S. K. Brown; J. L. Norelli; G. Hrazdina; H. S. Aldwinckle

2010-01-01

326

Enhanced conversion of plant biomass into glucose using transgenic rice-produced endoglucanase for cellulosic ethanol  

Microsoft Academic Search

The catalytic domain of Acidothermus cellulolyticus thermostable endoglucanase gene (encoding for endo-1,4-?-glucanase enzyme or E1) was constitutively expressed in rice. Molecular\\u000a analyses of T1 plants confirmed presence and expression of the transgene. The amount of E1 enzyme accounted for up to 4.9%\\u000a of the plant total soluble proteins, and its accumulation had no apparent deleterious effects on plant growth and

Hesham Oraby; Balan Venkatesh; Bruce Dale; Rashid Ahmad; Callista Ransom; James Oehmke; Mariam Sticklen

2007-01-01

327

Polymer mobility in cell walls of transgenic tomatoes with reduced polygalacturonase activity  

Microsoft Academic Search

Cell walls were prepared from unripe and red-ripe tomato fruit, cv. Ailsa Craig, and from ripe transgenic fruit carrying antisense genes downregulating the ripening-related polygalacturonase activity. The cell walls were examined by 13C NMR using a cross-polarization\\/magic-angle spinning experiment with variable contact time to estimate the proton magnetic relaxation parameter T1p, which is sensitive to molecular motions on the kHz

K. M. Fenwick; M. C. Jarvis; D. C. Apperley; G. B. Seymour; C. R. Bird

1996-01-01

328

Transgenic ‘Mailing 26’ apple expressing the attacin E gene has increased resistance to Erwinia amylovora  

Microsoft Academic Search

Summary  Apple (Malus domestica) transgenic T1 was obtained byAgrobacterium tumefaciens-mediated transformation of Malling 26 rootstock using the plasmid binary vector pLDB 15. pLDB 15 contains within its T -DNA\\u000a a gene encoding the lytic protein attacin E. The integration of the attacin E gene into the apple genome was confirmed by\\u000a Southern analysis. Northern analysis indicated the presence of an attacin

John L. Norelli; Herb S. Aldwinckle; Luis Destéfano-Beltrán; Jesse M. Jaynes

1994-01-01

329

Position independent expression and developmental regulation is directed by the beta myosin heavy chain gene's 5' upstream region in transgenic mice.  

PubMed Central

Transgenic mice generated with constructs containing 5.6 kb of the beta myosin heavy chain (MyHC) gene's 5' flanking region linked to the cat reporter gene express the transgene at high levels. In all 47 lines analyzed, tissue-specific accumulation of chloramphenicol acetyltransferase was found at levels proportional to the number of integrated transgene copies. Deletion constructs containing only 0.6 kb of 5' upstream region showed position effects in transgenic mice and did not demonstrate copy number dependence although transgene expression remained muscle-specific. The 5.6 kb 5' upstream region conferred appropriate developmental control of the transgene to the cardiac compartment and directs copy number dependent and position independent expression. Lines generated with a construct in which three proximal cis-acting elements were mutated showed reduced levels of transgene expression, but all maintained their position independence and copy number dependence, suggesting the presence of distinct regulatory mechanisms. Images

Knotts, S; Rindt, H; Robbins, J

1995-01-01

330

T1DBase: integration and presentation of complex data for type 1 diabetes research  

Microsoft Academic Search

ABSTRACT T1DBase (http:\\/\\/T1DBase.org) [Smink et al. (2005) Nucleic Acids Res., 33, D544–D549; Burren et al. (2004) Hum. Genomics, 1, 98–109] is a public website and database that supports the type 1 diabetes,(T1D) research,community.,T1DBase provides,a consolidated,T1D-oriented view,of the complex data world that now confronts medical researchers and enables scientists to navigate,from information,they know,to information,that is new,to them.,Overview pages for genes and

Erin M. Hulbert; Luc J. Smink; Ellen C. Adlem; James E. Allen; David B. Burdick; Oliver S. Burren; Christopher C. Cavnor; Geoffrey E. Dolman; Daisy Flamez; Karen F. Friery; Barry C. Healy; Sarah A. Killcoyne; Burak Kutlu; Helen Schuilenburg; Neil M. Walker; Josyf Mychaleckyj; Decio L. Eizirik; Linda S. Wicker; John A. Todd; Nathan Goodman

2007-01-01

331

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

332

Stable transformation and long-term maintenance of transgenic Taxus cell suspension cultures.  

PubMed

A cell line of Taxus cuspidata has been transformed with wild-type Agrobacterium rhizogenes ATCC strain 15834 containing binary vector pCAMBIA1301 and, separately, with A. tumefaciens strain EHA105 containing binary vector pCAMBIA1305.2. Additionally, a cell line of T. chinensis has been transformed with wild-type A. rhizogenes ATCC strain 25818 containing binary vector pCAMBIA1301. The two transgenic T. cuspidata cell lines have been maintained in culture for more than 20 months, and the transgenic T. chinensis cell line for more than 9 months, with no loss of reporter gene expression or antibiotic resistance. The introduced genes had no discernable effect on growth or Taxol production in the transgenic cell lines when compared to the parent control. The methods for transforming non-embryogenic Taxus suspension cultures are described. PMID:17333018

Ketchum, Raymond E B; Wherland, Lea; Croteau, Rodney B

2007-03-01

333

An improved prognostic model for stage T1a and T1b prostate cancer by assessments of cancer extent.  

PubMed

Treatment decisions on prostate cancer diagnosed by trans-urethral resection (TURP) of the prostate are difficult. The current TNM staging system for pT1 prostate cancer has not been re-evaluated for 25 years. Our objective was to optimise the predictive power of tumor extent measurements in TURP of the prostate specimens. A total of 914 patients diagnosed by TURP of the prostate between 1990 and 1996, managed conservatively were identified. The clinical end point was death from prostate cancer. Diagnostic serum prostate-specific antigen (PSA) and contemporary Gleason grading was available. Cancer extent was measured by the percentage of chips infiltrated by cancer. Death rates were compared by univariate and multivariate proportional hazards models, including baseline PSA and Gleason score. The percentage of positive chips was highly predictive of prostate cancer death when assessed as a continuous variable or as a grouped variable on the basis of and including the quintiles, quartiles, tertiles and median groups. In the univariate model, the most informative variable was a four group-split (?10%, >10-25%, >25-75% and >75%); (HR=2.08, 95% CI=1.8-2.4, P<0.0001). The same was true in a multivariate model (?X(2) (1 d.f.)=15.0, P=0.0001). The current cutoff used by TNM (<=5%) was sub-optimal (?X(2) (1 d.f.)=4.8, P=0.023). The current TNM staging results in substantial loss of information. Staging by a four-group subdivision would substantially improve prognostication in patients with early stage disease and also may help to refine management decisions in patients who would do well with conservative treatments. PMID:20834240

Rajab, Ramzi; Fisher, Gabrielle; Kattan, Michael W; Foster, Christopher S; Mřller, Henrik; Oliver, Tim; Reuter, Victor; Scardino, Peter T; Cuzick, Jack; Berney, Daniel M

2010-09-10

334

Quality and agronomic effects of three high-molecular-weight glutenin subunit transgenic events in winter wheat  

Technology Transfer Automated Retrieval System (TEKTRAN)

Quality and agronomic effects of three transgenic high-molecular-weight glutenin subunit (HMWGS) events were characterized in advanced-generation breeding lines of hard winter wheat (Triticum aestivum L.) in three Nebraska (U.S.A.) crop years. Two of the transgenic events studied, Dy10-E and B52a-6...

335

Effects of T4 Lysozyme Release from Transgenic Potato Roots on Bacterial Rhizosphere Communities Are Negligible Relative to Natural Factors  

Microsoft Academic Search

Rhizosphere bacterial communities of two transgenic potato lines which produce T4 lysozyme for protection against bacterial infections were analyzed in comparison to communities of wild-type plants and transgenic controls not harboring the lysozyme gene. Rhizosphere samples were taken from young, flowering, and senescent plants at two field sites in three consecutive years. The communities were characterized in a polyphasic approach.

Holger Heuer; Reiner M. Kroppenstedt; Jana Lottmann; Gabriele Berg; Kornelia Smalla

2002-01-01

336

Relation of Skin Polyamines to the Hairless Phenotype in Transgenic Mice Overexpressing Spermidine\\/Spermine N1Acetyltransferase  

Microsoft Academic Search

We recently generated a transgenic mouse line with activated polyamine catabolism due to overexpression of spermidine\\/spermine N1-acetyltransferase. Phenotypic changes in these animals included permanent loss of hair at the age of 3 wk. We have now further explored development of hair loss during early postnatal life. The first hair cycle appeared to be completed normally in the transgenic animals. At

Marko Pietilä; Jyrki J Parkkinen; Leena Alhonen; Juhani Jänne

2001-01-01

337

Population dynamics of Sesamia inferens on transgenic rice expressing Cry1Ac and CpTI in southern China.  

PubMed

Genetically modified insect-resistant rice lines containing the cry1Ac gene from Bacillus thuringiensis (Bt) or the CpTI (cowpea trypsin inhibitor) gene developed for the management of lepidopterous pests are highly resistant to the major target pests, Chilo suppressalis (Walker), Cnaphalocrocis medinalis (Guenée), and Scirpophaga incertulas (Walker), in the main rice-growing areas of China. However, the effects of these transgenic lines on Sesamia inferens (Walker), an important lepidopterous rice pest, are currently unknown. Because different insect species have varying susceptibility to Bt insecticidal proteins that may affect population dynamics, research into the effects of these transgenic rice lines on the population dynamics of S. inferens was conducted in Fuzhou, southern China, in 2005 and 2006. The results of laboratory, field cage, and field plot experiments show that S. inferens has comparatively high susceptibility to the transgenic line during the early growing season, with significant differences observed in larval density and infestation levels between transgenic and control lines. Because of a decrease in Cry1Ac levels in the plant as it ages, the transgenic line provided only a low potential for population suppression late in the growing season. There is a correlation between the changing expression of Cry1Ac and the impact of transgenic rice on the population dynamics of S. inferens during the season. These results indicate that S. inferens may become a major pest in fields of prospective commercially released transgenic rice, and more attention should be paid to developing an effective alternative management strategy. PMID:19036217

Han, Lanzhi; Liu, Peilei; Wu, Kongming; Peng, Yufa; Wang, Feng

2008-10-01

338

The functional role of the T1R family of receptors in sweet taste and feeding.  

PubMed

The discovery of the T1R family of Class C G protein-coupled receptors in the peripheral gustatory system a decade ago has been a tremendous advance for taste research, and its conceptual reach has extended to other organ systems. There are three proteins in the family, T1R1, T1R2, and T1R3, encoded by their respective genes, Tas1r1, Tas1r2, and Tas1r3. T1R2 combines with T1R3 to form a heterodimer that binds with sugars and other sweeteners. T1R3 also combines with T1R1 to form a heterodimer that binds with l-amino acids. These proteins are expressed not only in taste bud cells, but one or more of these T1Rs have also been identified in the nasal epithelium, gut, pancreas, liver, kidney, testes and brain in various mammalian species. Here we review current perspectives regarding the functional role of these receptors, concentrating on sweet taste and feeding. We also discuss behavioral findings suggesting that a glucose polymer mixture, Polycose, which rodents avidly prefer, appears to activate a receptor that does not depend on the combined expression of T1R2 and T1R3. In addition, although the T1Rs have been implicated as playing a role in glucose sensing, T1R2 knock-out (KO) and T1R3 KO mice display normal chow and fluid intake as well as normal body weight compared with same-sex littermate wild type (WT) controls. Moreover, regardless of whether they are fasted or not, these KO mice do not differ from their WT counterparts in their Polycose intake across a broad range of concentrations in 30-minute intake tests. The functional implications of these results and those in the literature are considered. PMID:21376068

Treesukosol, Yada; Smith, Kimberly R; Spector, Alan C

2011-03-02

339

Characterization of oligopeptide transporter (PepT1) in grass carp (Ctenopharyngodon idella).  

PubMed

The oligopeptide transporter (PepT1) is located on the brush-border membrane of the intestinal epithelium, and plays an important role in dipeptide and tripeptide absorptions from protein digestion. In this study, we cloned the PepT1 cDNA from grass carp and characterized its expression profile in response to dietary protein and feed additives (sodium butyrate) treatments. The PepT1 gene encodes a protein of 714 amino acids with high sequence similarity with other vertebrate homologues. Expression analysis revealed highest levels of PepT1 mRNA expression in the foregut of grass carp. In addition, PepT1 mRNA expression exhibited diurnal variation in all three bowel segments of intestine with lower levels of expression in daytime than nighttime. During embryonic development, PepT1 showed a dynamic pattern of expression reaching maximal levels of expression in the gastrula stage and minimal levels in the organ stage. The PepT1 expression showed constant levels from 14 to 34 day post-hatch. To determine whether fish diet of different protein contents may have any effect on PepT1 expression, we extended our research to dietary regulation of PepT1 expression. We found that dietary protein levels had a significant effect on PepT1 gene expression. In addition, PepT1 mRNA levels were higher after feeding with fish meal than with soybean meal. Moreover, in vitro and in vivo sodium butyrate treatments increased PepT1 expression in the intestine of grass carp. The results demonstrate for the first time that PepT1 mRNA expression is regulated in a temporal and spatial pattern during development, and dietary protein and feed additives had a significant effects on PepT1 gene expression in grass carp. PMID:23219926

Liu, Zhen; Zhou, Yi; Feng, Junchang; Lu, Shuangqing; Zhao, Qiong; Zhang, Jianshe

2012-12-04

340

The Functional Role of the T1R Family of Receptors in Sweet Taste and Feeding  

PubMed Central

The discovery of the T1R family of Class C G protein-coupled receptors in the peripheral gustatory system a decade ago has been a tremendous advance for taste research, and its conceptual reach has extended to other organ systems. There are three proteins in the family, T1R1, T1R2, and T1R3, encoded by their respective genes, Tas1r1, Tas1r2, and Tas1r3. T1R2 combines with T1R3 to form a heterodimer that binds with sugars and other sweeteners. T1R3 also combines with T1R1 to form a heterodimer that binds with L-amino acids. These proteins are expressed not only in taste bud cells, but one or more of these T1Rs have also been identified in the nasal epithelium, gut, pancreas, liver, kidney, testes and brain in various mammalian species. Here we review current perspectives regarding the functional role of these receptors, concentrating on sweet taste and feeding. We also discuss behavioral findings suggesting that a glucose polymer mixture, Polycose, which rodents avidly prefer, appears to activate a receptor that does not depend on the combined expression of T1R2 and T1R3. In addition, although the T1Rs have been implicated as playing a role in glucose sensing, T1R2 knock-out (KO) and T1R3 KO mice display normal chow and fluid intake as well as normal body weight compared with same-sex littermate wild type (WT) controls. Moreover, regardless of whether they are fasted or not, these KO mice do not differ from their WT counterparts in their Polycose intake across a broad range of concentrations in 30-min intake tests. The functional implications of these results and those in the literature are considered.

Treesukosol, Yada; Smith, Kimberly R.; Spector, Alan C.

2011-01-01

341

Butyrate Transcriptionally Enhances Peptide Transporter PepT1 Expression and Activity  

PubMed Central

Background PepT1, an intestinal epithelial apical di/tripeptide transporter, is normally expressed in the small intestine and induced in colon during chronic inflammation. This study aimed at investigating PepT1 regulation by butyrate, a short-chain fatty acid produced by commensal bacteria and accumulated inside inflamed colonocyte. Results We found that butyrate treatment of human intestinal epithelial Caco2-BBE cells increased human PepT1 (hPepT1) promoter activity in a dose- and time-dependent manner, with maximal activity observed in cells treated with 5 mM butyrate for 24 h. Under this condition, hPepT1 promoter activity, mRNA and protein expression levels were increased as assessed by luciferase assay, real-time RT-PCR and Western blot, respectively. hPepT1 transport activity was accordingly increased by ?2.5-fold. Butyrate did not alter hPepT1 mRNA half-life indicating that butyrate acts at the transcriptional level. Molecular analyses revealed that Cdx2 is the most important transcription factor for butyrate-induced increase of hPepT1 expression and activity in Caco2-BBE cells. Butyrate-activated Cdx2 binding to hPepT1 promoter was confirmed by gel shift and chromatin immunoprecipitation. Moreover, Caco2-BBE cells overexpressing Cdx2 exhibited greater hPepT1 expression level than wild-type cells. Finally, treatment of mice with 5 mM butyrate added to drinking water for 24 h increased colonic PepT1 mRNA and protein expression levels, as well as enhanced PepT1 transport activity in colonic apical membranes vesicles. Conclusions Collectively, our results demonstrate that butyrate increases PepT1 expression and activity in colonic epithelial cells, which provides a new understanding of PepT1 regulation during chronic inflammation.

Dalmasso, Guillaume; Nguyen, Hang Thi Thu; Yan, Yutao; Charrier-Hisamuddin, Laetitia; Sitaraman, Shanthi V.; Merlin, Didier

2008-01-01

342

Diabetes-Associated Dry Eye Syndrome in a New Humanized Transgenic Model of Type 1 Diabetes  

PubMed Central

Purpose Patients with Type 1 Diabetes (T1D) are at high risk of developing lacrimal gland dysfunction. We have developed a new model of human T1D using double-transgenic mice carrying HLA-DQ8 diabetes-susceptibility haplotype instead of mouse MHC-class II and expressing the human beta cell autoantigen Glutamic Acid Decarboxylase in pancreatic beta cells. We report here the development of dry eye syndrome (DES) after diabetes induction in our humanized transgenic model. Methods Double-transgenic mice were immunized with DNA encoding human GAD65, either naked or in adenoviral vectors, to induce T1D. Mice monitored for development of diabetes developed lacrimal gland dysfunction. Results Animals developed lacrimal gland disease (classically associated with diabetes in Non Obese Diabetic [NOD] mice and with T1D in humans) as they developed glucose intolerance and diabetes. Animals manifested obvious clinical signs of dry eye syndrome (DES), from corneal erosions to severe keratitis. Histological studies of peri-bulbar areas revealed lymphocytic infiltration of glandular structures. Indeed, infiltrative lesions were observed in lacrimal/Harderian glands within weeks following development of glucose intolerance. Lesions ranged from focal lymphocytic infiltration to complete acinar destruction. We observed a correlation between the severity of the pancreatic infiltration and the severity of the ocular disease. Conclusions Our results demonstrate development of DES in association with antigen-specific insulitis and diabetes following immunization with clinically relevant human autoantigen concomitantly expressed in pancreatic beta cells of diabetes-susceptible mice. As in the NOD mouse model and as in human T1D, our animals developed diabetes-associated DES. This specific finding stresses the relevance of our model for studying these human diseases. We believe our model will facilitate studies to prevent/treat diabetes-associated DES as well as human diabetes.

Imam, Shahnawaz; Elagin, Raya B.

2013-01-01

343

Orosensory detection of sucrose, maltose, and glucose is severely impaired in mice lacking T1R2 or T1R3, but Polycose sensitivity remains relatively normal  

PubMed Central

Evidence in the literature supports the hypothesis that the T1R2+3 heterodimer binds to compounds that humans describe as sweet. Here, we assessed the necessity of the T1R2 and T1R3 subunits in the maintenance of normal taste sensitivity to carbohydrate stimuli. We trained and tested water-restricted T1R2 knockout (KO), T1R3 KO and their wild-type (WT) same-sex littermate controls in a two-response operant procedure to sample a fluid and differentially respond on the basis of whether the stimulus was water or a tastant. Correct responses were reinforced with water and incorrect responses were punished with a time-out. Testing was conducted with a modified descending method of limits procedure across daily 25-min sessions. Both KO groups displayed severely impaired performance and markedly decreased sensitivity when required to discriminate water from sucrose, glucose, or maltose. In contrast, when Polycose was tested, KO mice had normal EC50 values for their psychometric functions, with some slight, but significant, impairment in performance. Sensitivity to NaCl did not differ between these mice and their WT controls. Our findings support the view that the T1R2+3 heterodimer is the principal receptor that mediates taste detection of natural sweeteners, but not of all carbohydrate stimuli. The combined presence of T1R2 and T1R3 appears unnecessary for the maintenance of relatively normal sensitivity to Polycose, at least in this task. Some detectability of sugars at high concentrations might be mediated by the putative polysaccharide taste receptor, the remaining T1R subunit forming either a homodimer or heteromer with another protein(s), or nontaste orosensory cues.

Treesukosol, Yada

2012-01-01

344

Epigenetic changes of lentiviral transgenes in porcine stem cells derived from embryonic origin.  

PubMed

Because of the physiological and immunological similarities that exist between pigs and humans, porcine pluripotent cell lines have been identified as important candidates for preliminary studies on human disease as well as a source for generating transgenic animals. Therefore, the establishment and characterization of porcine embryonic stem cells (pESCs), along with the generation of stable transgenic cell lines, is essential. In this study, we attempted to efficiently introduce transgenes into Epiblast stem cell (EpiSC)-like pESCs. Consequently, a pluripotent cell line could be derived from a porcine-hatched blastocyst. Enhanced green fluorescent protein (EGFP) was successfully introduced into the cells via lentiviral vectors under various multiplicities of infection, with pluripotency and differentiation potential unaffected after transfection. However, EGFP expression gradually declined during extended culture. This silencing effect was recovered by in vitro differentiation and treatment with 5-azadeoxycytidine. This phenomenon was related to DNA methylation as determined by bisulfite sequencing. In conclusion, we were able to successfully derive EpiSC-like pESCs and introduce transgenes into these cells using lentiviral vectors. This cell line could potentially be used as a donor cell source for transgenic pigs and may be a useful tool for studies involving EpiSC-like pESCs as well as aid in the understanding of the epigenetic regulation of transgenes. PMID:23977247

Choi, Kwang-Hwan; Park, Jin-Kyu; Kim, Hye-Sun; Uh, Kyung-Jun; Son, Dong-Chan; Lee, Chang-Kyu

2013-08-19

345

Viability and longevity of pollen from transgenic and nontransgenic tall fescue (Festuca arundinacea) (Poaceae) plants.  

PubMed

Pollen is an important vector of gene flow in plants, particularly for outcrossing species like tall fescue. Several aspects of pollination biology were investigated using pollen from transgenic and nontransgenic plants of tall fescue (Festuca arundinacea Schreb.), the most important forage species worldwide of the Festuca genus. To effectively assess in vitro pollen viability in tall fescue, an optimized germination medium (0.8 mol/L sucrose, 1.28 mmol/L boric acid and 1.27 mmol/L calcium nitrate) was developed. Treatment with relatively high temperatures (36° and 40°C) and high doses of UV-B irradiation (900-1500 ?W/cm(2)) reduced pollen viability, while relative humidity did not significantly influence pollen viability. Viability of pollen from transgenic progenies (T1 and T2) was similar to that from seed-derived control plants. Pollen from primary transgenics (T0) and primary regenerants (R0) had various levels of viability. Hand pollination using the primary regenerants and transgenics revealed that no seed set could be obtained when pollen viability was lower than 5%. Pollen from transgenic progenies and nontransgenic control plants could survive up to 22 h under controlled conditions in growth chamber. However, under sunny atmospheric conditions, viability of transgenic and nontransgenic pollen reduced to 5% in 30 min, with a complete loss of viability in 90 min. Under cloudy atmospheric conditions, pollen remained viable up to 240 min, with about 5% viability after 150 min. This report is the first on pollen viability and longevity in transgenic forage grasses and could be useful for risk assessment of transgenic plants. PMID:21653407

Wang, Zeng-Yu; Ge, Yaxin; Scott, Megann; Spangenberg, German

2004-04-01

346

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.

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

2012-01-01

347

Repeat-induced gene silencing of L1 transgenes is correlated with differential promoter methylation  

PubMed Central

Recent transgenic studies on L1 retrotransposons have afforded exciting insights into L1 biology, and a unique opportunity to model their function and regulation in vivo. Thus far, the majority of the transgenic L1 mouse lines are constructed via pronuclear microinjection, a procedure that typically results in the integration of tandem arrayed transgenes. Transgene arrays are susceptible to repeat-induced gene silencing (RIGS) in both plants and animals. In order to examine the potential impact of RIGS on L1 retrotransposition, we derived a cohort of animals carrying reduced copies of ORFeus transgene at the same genomic locus by Cre-mediated recombination. The copy number reduction of ORFeus transgenes did not decrease the overall retrotransposition activity. Using a sensitive and reproducible quantitative PCR assay, an average frequency of 0.45 insertions per cell was observed for animals carrying the donor transgene at a single copy, representing a 9-fold increase of retrotransposition frequency on a per-copy basis. DNA methylation analyses revealed that the observed retrotransposition activity was correlated with differential CpG methylation at the heterologous promoter: the promoter region was largely methylated in animals with the high-copy array but significantly hypomethylated in animals with the single-copy counterpart. In contrast, the ORF2 region, which represents the body of the ORFeus transgene, and the 3? end of the transgene showed high level of methylation in both high-copy and single-copy samples. The observed methylation patterns were metastable across generations. In summary, our data suggest that tandem arrayed L1 transgenes are subject to RIGS, and transgenes present at a single copy in the genome are thus recommended for modeling L1 in animals.

Rosser, James M.; An, Wenfeng

2010-01-01

348

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...

349

The choline oxidase gene codA confers salt tolerance to transgenic Eucalyptus globulus in a semi-confined condition.  

PubMed

The performance of tree species is influenced by environmental factors and growth stages. To evaluate the practical performance of transgenic tree species, it is insufficient to grow small, young trees under controlled conditions, such as in a growth chamber. Three transgenic Eucalyptus globulus lines, carrying the choline oxidase gene, were investigated for their salt tolerance and expression of the transgene at the young plantlet stage in a special netted-house. To clarify the characteristics at the young as well during the later stages, salt tolerance and the properties of the transgenic lines at large juvenile and adult stages were evaluated in the special netted-house. All transgenic lines showed high glycinebetaine content, particularly in young leaves. Trees of the transgenic line 107-1 showed low damage because of salinity stress based on the results from the chlorophyll analysis and malondialdehyde content, and they survived the high-salt-shock treatment at the large juvenile and adult stages. Only this line showed salt tolerance at all stages in the special netted-house. In this evaluation in the special netted-house, the tolerant line among young plantlets might perform better at all stages. Since evaluation in these special netted-house mimics field evaluation, line 107-1 is a potential tolerant line. PMID:22752644

Yu, Xiang; Kikuchi, Akira; Matsunaga, Etsuko; Morishita, Yoshihiko; Nanto, Kazuya; Sakurai, Nozomu; Suzuki, Hideyuki; Shibata, Daisuke; Shimada, Teruhisa; Watanabe, Kazuo N

2013-06-01

350

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.

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

2012-01-01

351

Hypoxia-induced in vivo sickling of transgenic mouse red cells.  

PubMed Central

To develop an animal model for sickle cell anemia, we have created transgenic mice that express a severe naturally occurring human sickling hemoglobin, Hb S Antilles. Due to its low solubility and oxygen affinity, Hb S Antilles has a greater propensity to cause red cell sickling than Hb S. To make transgenic animals that express a high level of Hb S Antilles, the erythroid-specific DNAse I hypersensitive site II from the human beta-globin cluster was linked independently to the human alpha 2-globin gene and to the beta S Antilles gene. Embryos were injected with both constructs simultaneously and seven transgenic mice were obtained, three of which contained both the human alpha and the human beta S Antilles transgene. After crossing the human transgenes into the mouse beta-thalassemic background a transgenic mouse line was derived in which approximately half the beta-globin chains in the murine red cells were human beta S Antilles. Deoxygenation of the transgenic red cells in vitro resulted in extensive sickling. An increase of in vivo sickling was achieved by placing these transgenic mice in a low oxygen environment. This murine model for red cell sickling should help to advance our understanding of sickle cell disease and may provide a model to test therapeutic interventions. Images

Rubin, E M; Witkowska, H E; Spangler, E; Curtin, P; Lubin, B H; Mohandas, N; Clift, S M

1991-01-01

352

A postimplantation lethal mutation induced by transgene insertion on mouse chromosome 8  

SciTech Connect

We have produced three lines of transgenic mice that contain additional copies of the mouse phosphoglycerate kinase 1 (Pgk1) gene. Two of these lines, 94-A and 94-K, which are descendants of a common founder, did not produce liveborn progeny carrying two copies of these transgenes (i.e., A/A, K/K, or A/K). Genotyping of midgestation embryos showed that A/K embryos are dead by Embryonic Day 10. Comparison of the level of transgene expression in the three transgenic lines ruled out PGK1 toxicity as the cause of death of A/A, A/K, and K/K embryos. The death of A/A, K/K, and A/K transgenic mice was therefore attributed to an insertional mutation disrupting a gene or genes essential for normal embryogenesis. Analysis of the structure of the 94-A and 94-K transgenes indicated that they differ in the number of tandem repeats and in the positions of the transgene-cellular DNA junctions. To determine if the two transgenes represent a single integration followed by a rearrangement or two independent integration events, we cloned the endogenous sequences surrounding the 94-A and 94-K transgene insertion sites. Restriction analysis of the isolated genomic clones indicated that the endogenous sequences abutting the 3{prime} ends of the 94-A and 94-K transgenes are separated by less than 20 kb, providing strong support for the single integration model. Further analysis indicated that the 94-A transgene is associated with a deletion of at least 18 kb and is located in the vicinity of a widely transcribed endogenous gene. Chromosomal mapping of the endogenous sequences flanking the 94-A and 94-K transgene insertions using mouse -hamster somatic cell hybrids and a (C57BL/6J X SPRET/Ei)F1 X SPRET/Ei backcross panel allowed us to assign the 94-A(K) transgene insertion to the subcentral region of mouse chromosome 8. 100 refs., 10 figs., 5 tabs.

Pravtcheva, D.D.; Wise, T.L. [Saint Louis Univ., MO (United States)

1995-12-10

353

Histopathological analysis of T1 renal cell carcinoma: Does presentation matter?  

PubMed Central

Objectives: To study the differences in the clinico-pathological features of incidental and symptomatic T1 renal cell carcinoma (RCC) and to see, particularly in T1b RCC, if symptomatic presentation has adverse pathological features concerning the oncological safety of elective nephron-sparing surgery (NSS) in this subgroup. Materials and Methods: Of 278 patients who underwent radical nephrectomy for RCC from January 1995 to January 2005, 70 had tumor size up to 7 cm (T1). They were categorized as incidental or symptomatic and as T1a or T1b tumors. Clinico-pathological features were compared between incidental (IRCC) and symptomatic (SRCC) groups. Tumors were analyzed using the 1997 TNM staging and Fuhrman's grade. Results: Of the 70 with T1 tumors, 24 had T1a (IRCC, 12 and SRCC, 12) and 46 had T1b tumors (IRCC, 27 and SRCC, 19). Clear cell was the commonest histology. In T1a cancers, though no significant difference in histopathological pattern and grade was seen between the incidental and symptomatic groups, symptomatic tumors had more papillary, mixed histopathological pattern and higher nuclear grade. Among T1b tumors, 14 had papillary and mixed histology, 12 (86%) of which were symptomatic (P= <0.0001). In T1b, 15 (79%) symptomatic had higher nuclear grade (G2-3) while 22 (81%) incidental had lower Fuhrman?s grade (P= <0.0001). Conclusion: Symptomatic T1b RCCs had higher nuclear grade and papillary histology. This difference was statistically significant. This may be relevant when considering elective NSS in symptomatic T1b disease.

Gupta, Gaurav; Adhikary, Samiran Das; Kumar, Santosh; Chacko, Ninan K.; Kekre, Nitin S.; Gopalakrishnan, Ganesh

2008-01-01

354

ZyFISH: A Simple, Rapid and Reliable Zygosity Assay for Transgenic Mice  

PubMed Central

Microinjection of DNA constructs into fertilized mouse oocytes typically results in random transgene integration at a single genomic locus. The resulting transgenic founders can be used to establish hemizygous transgenic mouse lines. However, practical and experimental reasons often require that such lines be bred to homozygosity. Transgene zygosity can be determined by progeny testing assays which are expensive and time-consuming, by quantitative Southern blotting which is labor-intensive, or by quantitative PCR (qPCR) which requires transgene-specific design. Here, we describe a zygosity assessment procedure based on fluorescent in situ hybridization (zyFISH). The zyFISH protocol entails the detection of transgenic loci by FISH and the concomitant assignment of homozygosity using a concise and unbiased scoring system. The method requires small volumes of blood, is scalable to at least 40 determinations per assay, and produces results entirely consistent with the progeny testing assay. This combination of reliability, simplicity and cost-effectiveness makes zyFISH a method of choice for transgenic mouse zygosity determinations.

McHugh, Donal; O'Connor, Tracy; Bremer, Juliane; Aguzzi, Adriano

2012-01-01

355

Using transgenic reporters to visualize bone and cartilage signaling during development in vivo  

PubMed Central

Green fluorescent protein was first used as a marker of protein expression in vivo 18 years ago, heralding the beginning of what became known as the Green Revolution. Since then, there has been an explosion in the number of transgenic lines in existence, and these transgenic tools are now being applied to skeletal research. Advances in transgenesis are also leading to increasing use of new model organisms for studying skeletogenesis. Such new models include the small teleosts zebrafish and medaka, which due to their optical translucency offer imaging possibilities in the live animals. In this review, we will introduce a number of recent advances in genetic engineering and transgenesis and the new genetic tools that are currently being developed. We will provide examples of how zebrafish and medaka transgenic lines are helping us to understand the behavior of skeletal cells in vivo. Finally, we will discuss future prospects for the application of transgenic technology to skeletal research.

Hammond, Chrissy L.; Moro, Enrico

2012-01-01

356

Transgenic approach for the study of pathogenesis induced by human viruses.  

PubMed

An understanding of the pathogenesis of human viral diseases has been hampered by the lack of suitable animal models. However, with the advent in the last decade of transgenic technology, it is now possible to introduce one or more viral genes into the germ-line of animals. Thus, transgenic technology allows for the study of viral gene expression and function in the context of the whole animal. The focus of this review is to define the advantages and disadvantages of the transgenic approach in studies of viral pathogenesis. Studies involving a human DNA tumor virus (JCV) and a human retrovirus (HIV) will be described to illustrate these points. PMID:2695742

Lassam, N; Feigenbaum, L; Vogel, J; Jay, G

1989-08-01

357

NCI-Frederick Transgenic and Knock-Out Services  

Cancer.gov

Transgenic and Knock-Out Services Transgenic Mouse Model Service Produces customized transgenic mice by pronuclear microinjection of fertilized mouse eggs Consultation in the design of the recombinant DNA constructs for use in transgenic studies Characterization

358

Disease resistance conferred by the expression of a gene encoding a synthetic peptide in transgenic cotton (Gossypium hirsutum L.) plants.  

PubMed

Fertile, transgenic cotton plants expressing the synthetic antimicrobial peptide, D4E1, were produced through Agrobacterium-mediated transformation. PCR products and Southern blots confirmed integration of the D4E1 gene, while RT-PCR of cotton RNA confirmed the presence of D4E1 transcripts. In vitro assays with crude leaf protein extracts from T0 and T1 plants confirmed that D4E1 was expressed at sufficient levels to inhibit the growth of Fusarium verticillioides and Verticillium dahliae compared to extracts from negative control plants transformed with pBI-d35S(Omega)-uidA-nos (CGUS). Although in vitro assays did not show control of pre-germinated spores of Aspergillus flavus, bioassays with cotton seeds in situ or in planta, inoculated with a GFP-expressing A. flavus, indicated that the transgenic cotton seeds inhibited extensive colonization and spread by the fungus in cotyledons and seed coats. In planta assays with the fungal pathogen, Thielaviopsis basicola, which causes black root rot in cotton, showed typical symptoms such as black discoloration and constriction on hypocotyls, reduced branching of roots in CGUS negative control T1 seedlings, while transgenic T1 seedlings showed a significant reduction in disease symptoms and increased seedling fresh weight, demonstrating tolerance to the fungal pathogen. Significant advantages of synthetic peptides in developing transgenic crop plants that are resistant to diseases and mycotoxin-causing fungal pathogens are highlighted in this report. PMID:17147626

Rajasekaran, Kanniah; Cary, Jeffrey W; Jaynes, Jesse M; Cleveland, Thomas E

2005-11-01

359

An Updated Critical Analysis of the Treatment Strategy for Newly Diagnosed High-grade T1 (Previously T1G3) Bladder Cancer  

Microsoft Academic Search

ContextHigh-grade T1 (formerly T1G3) bladder cancer (BCa) has a high propensity to recur and progress. As a result, decisions pertaining to its treatment are difficult. Treatment with bacillus Calmette-Guérin (BCG) risks progression and metastases but may preserve the bladder. Cystectomy may offer the best opportunity for cure but is associated with morbidity and a risk of mortality, and it may

Girish S. Kulkarni; Oliver W. Hakenberg; Juergen E. Gschwend; George Thalmann; Wassim Kassouf; Ashish Kamat; Alexandre Zlotta

2010-01-01

360

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.

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

2011-01-01

361

Taste responses in mice lacking taste receptor subunit T1R1.  

PubMed

The T1R1 receptor subunit acts as an umami taste receptor in combination with its partner, T1R3. In addition, metabotropic glutamate receptors (brain and taste variants of mGluR1 and mGluR4) are thought to function as umami taste receptors. To elucidate the function of T1R1 and the contribution of mGluRs to umami taste detection in vivo, we used newly developed knock-out (T1R1(-/-)) mice, which lack the entire coding region of the Tas1r1 gene and express mCherry in T1R1-expressing cells. Gustatory nerve recordings demonstrated that T1R1(-/-) mice exhibited a serious deficit in inosine monophosphate-elicited synergy but substantial residual responses to glutamate alone in both chorda tympani and glossopharyngeal nerves. Interestingly, chorda tympani nerve responses to sweeteners were smaller in T1R1(-/-) mice. Taste cell recordings demonstrated that many mCherry-expressing taste cells in T1R1(+/-) mice responded to sweet and umami compounds, whereas those in T1R1(-/-) mice responded to sweet stimuli. The proportion of sweet-responsive cells was smaller in T1R1(-/-) than in T1R1(+/-) mice. Single-cell RT-PCR demonstrated that some single mCherry-expressing cells expressed all three T1R subunits. Chorda tympani and glossopharyngeal nerve responses to glutamate were significantly inhibited by addition of mGluR antagonists in both T1R1(-/-) and T1R1(+/-) mice. Conditioned taste aversion tests demonstrated that both T1R1(-/-) and T1R1(+/-) mice were equally capable of discriminating glutamate from other basic taste stimuli. Avoidance conditioned to glutamate was significantly reduced by addition of mGluR antagonists. These results suggest that T1R1-expressing cells mainly contribute to umami taste synergism and partly to sweet sensitivity and that mGluRs are involved in the detection of umami compounds. PMID:23339178

Kusuhara, Yoko; Yoshida, Ryusuke; Ohkuri, Tadahiro; Yasumatsu, Keiko; Voigt, Anja; Hübner, Sandra; Maeda, Katsumasa; Boehm, Ulrich; Meyerhof, Wolfgang; Ninomiya, Yuzo

2013-01-21

362

Expression and Assembly of Cholera Toxin B Subunit (CTB) in Transgenic Carrot ( Daucus carota L.)  

Microsoft Academic Search

We expressed the cholera toxin B subunit (CTB) fused to an endoplasmic reticulum retention signal (SEKDEL) in carrot roots\\u000a using an Agrobacterium-mediated transformation method. Fourteen independent transgenic lines were regenerated via somatic embryogenesis after 6 months\\u000a of culture. The sCTB gene was detected in the genomic DNA of transgenic carrot by PCR amplification. Expressions and assembly\\u000a of sCTB protein into oligomeric

Young-Sook Kim; Mi-Young Kim; Tae-Geum Kim; Moon-Sik Yang

2009-01-01

363

Production of transgenic cloned piglets from genetically transformed fetal fibroblasts selected by green fluorescent protein  

Microsoft Academic Search

This study was performed to develop a system for porcine somatic cell nuclear transfer (SCNT) and to produce human erythropoietin (hEPO)-transgenic cloned piglets. Porcine fetal fibroblasts were transfected with an expression plasmid (phEPO-GFP). In Experiment 1, the effect of transfection of phEPO-GFP transgene on development of porcine SCNT embryos was investigated. Three fetal fibroblast cell lines (two male and one

Gab sang Lee; Hye soo Kim; Sang hwan Hyun; So hyun Lee; Hyun yong Jeon; Dong hyun Nam; Yeon woo Jeong; Sue Kim; Ji hye Kim; Jae yong Han; Curie Ahn; Sung keun Kang; Byeong chun Lee; Woo suk Hwang

2005-01-01

364

A construct-specific qualitative and quantitative PCR detection method of transgenic maize BVLA430101  

Microsoft Academic Search

Transgenic phytase maize (Zea mays\\u000a L.) line BVLA430101 was the first transgenic maize obtained the security certification in 2009 in China. However, the construct\\u000a of the phytase gene expression cassette and the specific detection method have not been reported yet. In this study, the phytase\\u000a gene expression cassette was identified, which include maize legumin promoter, signal peptide, phytase gene, and

Changqing Su; Yao Sun; Jiajian Xie; Yufa Peng

2011-01-01

365

Improved Carica papaya Tolerance to Carmine Spider Mite by the Expression of Manduca sexta chitinase Transgene  

Microsoft Academic Search

Papaya plants producing the tobacco hornworm (Manduca sexta) chitinase protein were obtained following microprojectile bombardment of embryogenic calli derived from the hypocotyls of\\u000a the cultivar Kapoho. Polymerase chain reaction (PCR) was carried out to confirm the presence of the transgene. RT-PCR and\\u000a a quantitative chitinase assay showed increased levels of chitinase activity in every selected transgenic line. Insect bioassays\\u000a in

Heather R. K. McCafferty; Paul H. Moore; Yun J. Zhu

2006-01-01

366

Targeted Oncogene Activation by Site-Specific Recombination in Transgenic Mice  

Microsoft Academic Search

An efficient and accurate method for controlled in vivo transgene modulation by site-directed recombination is described. Seven transgenic mouse founder lines were produced carrying the murine lens-specific alphaA-crystallin promoter and the simian virus 40 large tumor-antigen gene sequence, separated by a 1.3-kilobase-pair Stop sequence that contains elements preventing expression of the large tumor-antigen gene and Cre recombinase recognition sites. Progeny

M. Lakso; B. Sauer; B. Mosinger Jr.; E. J. Lee; R. W. Manning; S.-H. Yu; K. L. Mulder; H. Westphal

1992-01-01

367

Functional imaging of interleukin 1 beta expression in inflammatory process using bioluminescence imaging in transgenic mice  

Microsoft Academic Search

BACKGROUND: Interleukin 1 beta (IL-1?) plays an important role in a number of chronic and acute inflammatory diseases. To understand the role of IL-1? in disease processes and develop an in vivo screening system for anti-inflammatory drugs, a transgenic mouse line was generated which incorporated the transgene firefly luciferase gene driven by a 4.5-kb fragment of the human IL-1? gene

Limei Li; Zhaoliang Fei; Jianke Ren; Ruilin Sun; Zhihui Liu; Zhejin Sheng; Long Wang; Xia Sun; Jun Yu; Zhugang Wang; Jian Fei

2008-01-01

368

Erythroid defects and increased retrovirally-induced tumor formation in Evi1 transgenic mice  

Microsoft Academic Search

Aberrant expression of the Evi1 (ecotropic virus integration site 1) proto-oncogene has been associated with hematopoietic malignancies in both mice and man. To determine the effect of enforced expression of Evi1 in vivo, we developed a transgenic mouse model utilizing the murine Sca-1 (Ly-6E.1) promoter. Here, we describe the generation and analysis of three independent lines of Evi1 transgenic mice.

D Louz; M van den Broek; S Verbakel; Y Vankan; K van Lom; M Joosten; D Meijer; B Löwenberg; R Delwel

2000-01-01

369

Regeneration of Populus nigra transgenic plants expressing a Kunitz proteinase inhibitor (KTi 3 ) gene  

Microsoft Academic Search

Transgenic poplar (Populus nigra, cv. Jean Pourtet) plants were recovered as a result of Agrobacterium tumefaciens-mediated transformation performed with EHA105 pBI-KUN strain. Plasmid pBI-KUN contains a 650 bp insert derived from the soybean (Glycine max L.) KTi3, gene, coding for a Kunitz trypsin proteinase inhibitor. A total of 58 independent transgenic lines were obtained from 200 co-cultivated leaf explants. Southern

Massimo Confalonieri; Gianni Allegro; Alma Balestrazzi; Corrado Fogher; Massimo Delledonne

1998-01-01

370

Impaired expression of chimaeric major histocompatibility complex transgenes associated with plasmid sequences  

Microsoft Academic Search

Plasmid vector sequences were retained (vector+), or removed (vector?) from hybrid major histocompatibility comlex gene constructs prior to microinjection of fertilized ova for the production\\u000a of transgenic mice. In transgenic mice containing integrated vector+ gene constructs, low levels of class II cell surface determinants were detected on splenocytes from only two out of six independent\\u000a lines. Class II membrane determinants

Lars Kjer-Nielsen; Karen Holmberg; Jeanne D. Perera; James McCluskey

1992-01-01

371

Resistance mechanisms in protoporphyrinogen oxidase (PROTOX) inhibitor-resistant transgenic rice  

Microsoft Academic Search

We investigated the mechanism for conferring herbicide resistance in transgenic rice. Plants from Line M4 were resistant to\\u000a PROTOX inhibitors and had yields similar to those from wild-type (WT) rice.Myxococcus xanthus PROTOX mRNA was abundantly expressed in the transgenic leaf tissues, and theM. xanthus PROTOX gene was stably transmitted into the T4 generation. We detected a protein with a predicted

Ha Il Jung; Yong In Kuk

2007-01-01

372

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

373

Transgenic Animals for Testing Multidrug Resistance.  

National Technical Information Service (NTIS)

Transgenic animals carrying and expressing human MDR1 gene have been produced. These transgenic animals serve as a useful model for testing the efficacy of high dosage chemotherapy and for the development of novel chemotherapeutic agents against cancers. ...

I. Pastan

1988-01-01

374

Zebrafish sp7:EGFP: a transgenic for studying otic vesicle formation, skeletogenesis, and bone regeneration  

PubMed Central

Summary We report the expression pattern and construction of a transgenic zebrafish line for a transcription factor involved in otic vesicle formation and skeletogenesis. The zinc finger transcription factor sp7 (formerly called osterix) is reported as a marker of osteoblasts. Using bacterial artificial chromosome (BAC)-mediated transgenesis, we generated a zebrafish transgenic line for studying skeletal development, Tg(sp7:EGFP)b1212. Using a zebrafish BAC, EGFP was introduced downstream of the regulatory regions of sp7 and injected into 1 cell-stage embryos. In this transgenic line, GFP expression reproduces endogenous sp7 gene expression in the otic placode and vesicle, and in forming skeletal structures. GFP-positive cells were also detected in adult fish, and were found associated with regenerating fin rays post-amputation. This line provides an essential tool for the further study of zebrafish otic vesicle formation and the development and regeneration of the skeleton.

DeLaurier, April; Eames, B. Frank; Blanco-Sanchez, Bernardo; Peng, Gang; He, Xinjun; Swartz, Mary E.; Ullmann, Bonnie; Westerfield, Monte; Kimmel, Charles B.

2010-01-01

375

Virus-derived transgenes expressing hairpin RNA give immunity to Tobacco mosaic virus and Cucumber mosaic virus  

PubMed Central

Background An effective method for obtaining resistant transgenic plants is to induce RNA silencing by expressing virus-derived dsRNA in plants and this method has been successfully implemented for the generation of different plant lines resistant to many plant viruses. Results Inverted repeats of the partial Tobacco mosaic virus (TMV) movement protein (MP) gene and the partial Cucumber mosaic virus (CMV) replication protein (Rep) gene were introduced into the plant expression vector and the recombinant plasmids were transformed into Agrobacterium tumefaciens. Agrobacterium-mediated transformation was carried out and three transgenic tobacco lines (MP16-17-3, MP16-17-29 and MP16-17-58) immune to TMV infection and three transgenic tobacco lines (Rep15-1-1, Rep15-1-7 and Rep15-1-32) immune to CMV infection were obtained. Virus inoculation assays showed that the resistance of these transgenic plants could inherit and keep stable in T4 progeny. The low temperature (15?) did not influence the resistance of transgenic plants. There was no significant correlation between the resistance and the copy number of the transgene. CMV infection could not break the resistance to TMV in the transgenic tobacco plants expressing TMV hairpin MP RNA. Conclusions We have demonstrated that transgenic tobacco plants expressed partial TMV movement gene and partial CMV replicase gene in the form of an intermolecular intron-hairpin RNA exhibited complete resistance to TMV or CMV infection.

2011-01-01

376

Determining whether transgenic and endogenous plant DNA and transgenic protein are detectable in muscle from swine  

Microsoft Academic Search

Questions regarding the digestive fate of DNA and protein from transgenic feed have been raisedinregardtohumanconsumptionandcommercial trade of animal products (e.g., meat, milk, and eggs) from farm animals fed transgenic crops. Using highly sensitive, well-characterized analytical methods, pork loin samples were analyzed for the presence of frag- ments of transgenic and endogenous plant DNA and transgenic protein from animals fed meal

J. C. Jennings; D. C. Kolwyck; S. B. Kays; A. J. Whetsell; J. B. Surber; G. L. Cromwell; R. P. Lirette; K. C. Glenn

377

Clinical significance of T1-weighted MR images following transient cerebral ischemia  

Microsoft Academic Search

To try to determine the cause of hyperintensity of T1-weighted MR images that occurred on and after day 7 following transient cerebral ischemia, dynamic changes in T1-weighted images and histology of rats subjected to 20 min of 4-vessel occlusion were observed. T1-weighted images showed no remarkable alteration on days 1 and 3, although high signal intensity in the striatal region,

Hisami Aoe; Yoshimasa Takeda; Hidero Kawahara; Akio Tanaka; Kiyoshi Morita

2006-01-01

378

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

379

Transgenic Campanula carpatica plants with reduced ethylene sensitivity  

Microsoft Academic Search

Fertile transgenic Campanula carpatica Jacq. plants with flowers, which had reduced sensitivity to ethylene were obtained by Agrobacterium tumefaciens that mediated transformation. The construct used for transformation contained the etr1-1 gene from Arabidopsis thaliana under control of the flower specific fbp1-promoter from petunia. More than 100 flowering T0 lines were tested for their ethylene sensitivity using 2 ?l l?1 ethylene. The tolerance

Sridevy Sriskandarajah; Heiko Mibus; Margrethe Serek

2007-01-01

380

Progressive motor weakness in transgenic mice expressing human TDP43  

Microsoft Academic Search

Familial ALS patients with TDP-43 gene mutations and sporadic ALS patients share common TDP-43 neuronal pathology. To delineate mechanisms underlying TDP-43 proteinopathies, transgenic mice expressing A315T, M337V or wild type human TDP-43 were generated. Multiple TDP-43 founders developed a severe early motor phenotype that correlated with TDP-43 levels in spinal cord. Three A315T TDP-43 lines developed later onset paralysis with

Nancy R. Stallings; Krishna Puttaparthi; Christina M. Luther; Dennis K. Burns; Jeffrey L. Elliott

2010-01-01

381

Multiplicative or t1 Noise in NMR Spectroscopy  

SciTech Connect

The signal in an NMR experiment is highly sensitive to fluctuations of the environment of the sample. If, for example, the static magnetic field B{sub 0}, the amplitude and phase of radio frequency (rf) pulses, or the resonant frequency of the detection circuit are not perfectly stable and reproducible, the magnetic moment of the spins is altered and becomes a noisy quantity itself. This kind of noise not only depends on the presence of a signal, it is in fact proportional to it. Since all the spins at a particular location in a sample experience the same environment at any given time, this noise primarily affects the reproducibility of an experiment, which is mainly of importance in the indirect dimensions of a multidimensional experiment, when intense lines are suppressed with a phase cycle, or for difference spectroscopy techniques. Equivalently, experiments which are known to be problematic with regard to their reproducibility, like flow experiments or experiments with a mobile target, tend to be affected stronger by multiplicative noise. In this article it is demonstrated how multiplicative noise can be identified and characterized using very simple, repetitive experiments. An error estimation approach is developed to give an intuitive, yet quantitative understanding of its properties. The consequences for multidimensional NMR experiments are outlined, implications for data analysis are shown, and strategies for the optimization of experiments are summarized.

Granwehr, Josef

2005-01-25

382

Hyperspectral studies of transgenic oilseed rape  

Microsoft Academic Search

One risk of planting transgenic crops is the escape of transgenes to conspecifics and sexually compatible wild relatives. Detecting transgene escape is thus a crucial biosafety issue world-wide, but most current detection methods are expensive and laborious, as well as being unfeasible for large-scale use in commercial cultivation. We undertook field spectral reflectance studies of non-transgenic oilseed rape (B. napus

Hong Jiang; Wei Wei; Xiaodong Song; C. Neal Stewart Jr.; Guomo Zhou; Zishan Jiang; Qiuan Zhu; Shuquan Yu; Shaolin Peng

2011-01-01

383

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

384

B islet cells of pancreas are the site of expression of the human insulin gene in transgenic mice  

SciTech Connect

Transgenic mouse lines carrying the human insulin gene were previously shown to express it in pancreas but not in other tissues. The present study reports evidence that the expression of the transgene is restricted to a single category of cells. Immunofluorescence staining of frozen pancreas sections showed that the human C-peptide was present in pancreatic islets only, and more precisely in the B cells of the islets. Human insulin transcripts were initiated correctly in mouse pancreas at the same site as in human pancreas. Three different transgenic lines with different insertion sites and various copy numbers of the human insulin transgene had the same high levels of the transgene transcripts corresponding to a well-balanced contribution in insulin gene expression.

Bucchini, D.; Desbois, P.; Pictet, R.; Jami, J. (Univ. Paris 7 (France)); Madsen, O. (Hagedorn Research Lab., Gentofte (Denmark))

1989-02-01

385

Approaches to Minimize Variation of Transgene Expression in Plants  

Microsoft Academic Search

Genetic transformation of plants has become a widely used technology that serves multiple purposes in plant biology research. However, considerable variation of transgene expression is often observed within populations of transgenic plants transformed with the same transgene construct. This inter-transformant variation of transgene expression hampers proper evaluation of transgenes and might be most undesirable when high-throughput transgene screening is intended.

Katleen M. J. Butaye; Bruno P. A. Cammue; Stijn L. Delaureand; Miguel F. C. De Bolle

2005-01-01

386

Inbred maize line Ph0R8  

US Patent & Trademark Office Database

An inbred maize line, designated PH0R8, the plants and seeds of inbred maize line PH0R8, methods for producing a maize plant, either inbred or hybrid, produced by crossing the inbred maize line PH0R8 with itself or with another maize plant, and hybrid maize seeds and plants produced by crossing the inbred line PH0R8 with another maize line or plant and to methods for producing a maize plant containing in its genetic material one or more transgenes and to the transgenic maize plants produced by that method. This invention also relates to inbred maize lines derived from inbred maize line PH0R8, to methods for producing other inbred maize lines derived from inbred maize line PH0R8 and to the inbred maize lines derived by the use of those methods.

2004-04-06

387

Liver, meconium, haemorrhage: the value of T1-weighted images in fetal MRI  

Microsoft Academic Search

Background  Ultrafast T2-weighted (T2-W) MRI sequences are currently considered a routine technique for fetal MR imaging. Limited experience exists with fetal T1-weighted (T1-W) imaging techniques.Objective  To determine MRI patterns of some fetal abdominal or haemorrhagic disorders with particular respect to the diagnostic value of T1-W images.Materials and methods  In addition to standard T2-W single-shot sequences, T1-W single-shot and\\/or multislice sequences were employed in

Jan Zizka; Pavel Elias; Karel Hodik; Jaroslav Tintera; Vera Juttnerova; Zdenek Belobradek; Ludovit Klzo

2006-01-01

388

Optimized efficient liver T1? mapping using limited spin lock times  

NASA Astrophysics Data System (ADS)

T1? relaxation has recently been found to be sensitive to liver fibrosis and has potential to be used for early detection of liver fibrosis and grading. Liver T1? imaging and accurate mapping are challenging because of the long scan time, respiration motion and high specific absorption rate. Reduction and optimization of spin lock times (TSLs) are an efficient way to reduce scan time and radiofrequency energy deposition of T1? imaging, but maintain the near-optimal precision of T1? mapping. This work analyzes the precision in T1? estimation with limited, in particular two, spin lock times, and explores the feasibility of using two specific operator-selected TSLs for efficient and accurate liver T1? mapping. Two optimized TSLs were derived by theoretical analysis and numerical simulations first, and tested experimentally by in vivo rat liver T1? imaging at 3 T. The simulation showed that the TSLs of 1 and 50 ms gave optimal T1? estimation in a range of 10-100 ms. In the experiment, no significant statistical difference was found between the T1? maps generated using the optimized two-TSL combination and the maps generated using the six TSLs of [1, 10, 20, 30, 40, 50] ms according to one-way ANOVA analysis (p = 0.1364 for liver and p = 0.8708 for muscle).

Yuan, Jing; Zhao, Feng; Griffith, James F.; Chan, Queenie; Wang, Yi-Xiang J.

2012-03-01

389

Optimized efficient liver T(1?) mapping using limited spin lock times.  

PubMed

T(1?) relaxation has recently been found to be sensitive to liver fibrosis and has potential to be used for early detection of liver fibrosis and grading. Liver T(1?) imaging and accurate mapping are challenging because of the long scan time, respiration motion and high specific absorption rate. Reduction and optimization of spin lock times (TSLs) are an efficient way to reduce scan time and radiofrequency energy deposition of T(1?) imaging, but maintain the near-optimal precision of T(1?) mapping. This work analyzes the precision in T(1?) estimation with limited, in particular two, spin lock times, and explores the feasibility of using two specific operator-selected TSLs for efficient and accurate liver T(1?) mapping. Two optimized TSLs were derived by theoretical analysis and numerical simulations first, and tested experimentally by in vivo rat liver T(1?) imaging at 3 T. The simulation showed that the TSLs of 1 and 50 ms gave optimal T(1?) estimation in a range of 10-100 ms. In the experiment, no significant statistical difference was found between the T(1?) maps generated using the optimized two-TSL combination and the maps generated using the six TSLs of [1, 10, 20, 30, 40, 50] ms according to one-way ANOVA analysis (p = 0.1364 for liver and p = 0.8708 for muscle). PMID:22398137

Yuan, Jing; Zhao, Feng; Griffith, James F; Chan, Queenie; Wang, Yi-Xiang J

2012-03-07

390

Phase-sensitive inversion recovery for myocardial T1 mapping with motion correction and parametric fitting.  

PubMed

The assessment of myocardial fibrosis and extracellular volume requires accurate estimation of myocardial T1 s. While image acquisition using the modified Look-Locker inversion recovery technique is clinically feasible for myocardial T1 mapping, respiratory motion can limit its applicability. Moreover, the conventional T1 fitting approach using the magnitude inversion recovery images can lead to less stable T1 estimates and increased computational cost. In this article, we propose a novel T1 mapping scheme that is based on phase-sensitive image reconstruction and the restoration of polarity of the MR signal after inversion. The motion correction is achieved by registering the reconstructed images after background phase removal. The restored signal polarity of the inversion recovery signal helps the T1 fitting resulting in improved quality of the T1 map and reducing the computational cost. Quantitative validation on a data cohort of 45 patients proves the robustness of the proposed method against varying image contrast. Compared to the magnitude T1 fitting, the proposed phase-sensitive method leads to less fluctuation in T1 estimates. PMID:22736380

Xue, Hui; Greiser, Andreas; Zuehlsdorff, Sven; Jolly, Marie-Pierre; Guehring, Jens; Arai, Andrew E; Kellman, Peter

2012-06-26

391

Phenoxy herbicides and fibrates potently inhibit the human chemosensory receptor subunit T1R3  

PubMed Central

We show that phenoxy-auxin herbicides and lipid-lowering fibrates inhibit human but not rodent T1R3. T1R3 as a co-receptor in taste cells responds to sweet compounds and amino-acids; in endocrine cells of gut and pancreas T1R3 contributes to glucose sensing. Thus, certain effects of fibrates in treating hyperlipidemia and type II diabetes may be via actions on T1R3. Likewise, phenoxy-herbicides may have adverse metabolic effects in humans that would have gone undetected in studies on rodents.

Maillet, Emeline L.; Margolskee, Robert F.; Mosinger, Bedrich

200