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Transgene

About: Transgene is a research topic. Over the lifetime, 22794 publications have been published within this topic receiving 1120648 citations. The topic is also known as: transgenes.


Papers
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Journal ArticleDOI
19 Mar 1992-Nature
TL;DR: Observations indicate that a normal p53 gene is dispensable for embryonic development, that its absence predisposes the animal to neoplastic disease, and that an oncogenic mutant form of p53 is not obligatory for the genesis of many types of tumours.
Abstract: Mutations in the p53 tumour-suppressor gene are the most frequently observed genetic lesions in human cancers. To investigate the role of the p53 gene in mammalian development and tumorigenesis, a null mutation was introduced into the gene by homologous recombination in murine embryonic stem cells. Mice homozygous for the null allele appear normal but are prone to the spontaneous development of a variety of neoplasms by 6 months of age. These observations indicate that a normal p53 gene is dispensable for embryonic development, that its absence predisposes the animal to neoplastic disease, and that an oncogenic mutant form of p53 is not obligatory for the genesis of many types of tumours.

4,710 citations

Journal ArticleDOI
TL;DR: Somatic reversion of plants with white flowers to phenotypically parental violet flowers was associated with a coordinate rise in the steady-state levels of the mRNAs produced by both the endogenous and the introduced CHS genes, indicating that expression of the introduced chalcone synthase gene was not alone sufficient for suppression of endogenous CHS transcript levels.
Abstract: We attempted to overexpress chalcone synthase (CHS) in pigmented petunia petals by introducing a chimeric petunia CHS gene. Unexpectedly, the introduced gene created a block in anthocyanin biosynthesis. Forty-two percent of plants with the introduced CHS gene produced totally white flowers and/or patterned flowers with white or pale nonclonal sectors on a wild-type pigmented background; none of hundreds of transgenic control plants exhibited such phenotypes. Progeny testing of one plant demonstrated that the novel color phenotype co-segregated with the introduced CHS gene; progeny without this gene were phenotypically wild type. The somatic and germinal stability of the novel color patterns was variable. RNase protection analysis of petal RNAs isolated from white flowers showed that, although the developmental timing of mRNA expression of the endogenous CHS gene was not altered, the level of the mRNA produced by this gene was reduced 50-fold from wild-type levels. Somatic reversion of plants with white flowers to phenotypically parental violet flowers was associated with a coordinate rise in the steady-state levels of the mRNAs produced by both the endogenous and the introduced CHS genes. Thus, in the altered white flowers, the expression of both genes was coordinately suppressed, indicating that expression of the introduced CHS gene was not alone sufficient for suppression of endogenous CHS transcript levels. The mechanism responsible for the reversible co-suppression of homologous genes in trans is unclear, but the erratic and reversible nature of this phenomenon suggests the possible involvement of methylation.

2,994 citations

Journal ArticleDOI
12 Jul 2007-Nature
TL;DR: The generation and validation of a genome-wide library of Drosophila melanogaster RNAi transgenes, enabling the conditional inactivation of gene function in specific tissues of the intact organism and opening up the prospect of systematically analysing gene functions in any tissue and at any stage of the Drosophile lifespan.
Abstract: Forward genetic screens in model organisms have provided important insights into numerous aspects of development, physiology and pathology. With the availability of complete genome sequences and the introduction of RNA-mediated gene interference (RNAi), systematic reverse genetic screens are now also possible. Until now, such genome-wide RNAi screens have mostly been restricted to cultured cells and ubiquitous gene inactivation in Caenorhabditis elegans. This powerful approach has not yet been applied in a tissue-specific manner. Here we report the generation and validation of a genome-wide library of Drosophila melanogaster RNAi transgenes, enabling the conditional inactivation of gene function in specific tissues of the intact organism. Our RNAi transgenes consist of short gene fragments cloned as inverted repeats and expressed using the binary GAL4/UAS system. We generated 22,270 transgenic lines, covering 88% of the predicted protein-coding genes in the Drosophila genome. Molecular and phenotypic assays indicate that the majority of these transgenes are functional. Our transgenic RNAi library thus opens up the prospect of systematically analysing gene functions in any tissue and at any stage of the Drosophila lifespan.

2,721 citations

Patent
18 Mar 1992
TL;DR: In this paper, a transgenes containing sequences of unrearranged heterologous human immunoglobulin heavy chains are introduced into a non-human animal, thereby forming a transgenic animal capable of functionally rearranging transgenio-globulin sequences and producing a repertoire of antibodies.
Abstract: The invention relates to transgenic non-human animals capable of producing heterologous antibodies and transgenic non-human animals having inactivated endogenous immunoglobulin genes. In one aspect of the invention, endogenous immunoglobulin genes are suppressed by antisense polynucleotides and/or by antiserum directed against endogenous immunoglobulins. Heterologous antibodies are encoded by immunoglobulin genes not normally found in the genome of that species of non-human animal. In one aspect of the invention, one or more transgenes containing sequences of unrearranged heterologous human immunoglobulin heavy chains are introduced into a non-human animal thereby forming a transgenic animal capable of functionally rearranging transgenic immunoglobulin sequences and producing a repertoire of antibodies of various isotypes encoded by human immunoglobulin genes. Such heterologous human antibodies are produced in B-cells which are thereafter immortalized, e.g., by fusing with an immortalizing cell line such as a myeloma or by manipulating such B-cells by other techniques to perpetuate a cell line capable of producing a monoclonal heterologous antibody. The invention also relates to heavy and light chain immunoglobulin transgenes for making such transgenic non-human animals as well as methods and vectors for disrupting endogenous immunoglobulin loci in the transgenic animal.

2,692 citations

Journal ArticleDOI
23 Jun 1995-Science
TL;DR: Adding doxycycline to HeLa cells that constitutively synthesized the transactivator and that contained an appropriate, stably integrated reporter unit rapidly induced gene expression more than a thousandfold.
Abstract: A transcriptional transactivator was developed that fuses the VP16 activation domain with a mutant Tet repressor from Escherichia coli. This transactivator requires certain tetracycline (Tc) derivatives for specific DNA binding. Thus, addition of doxycycline to HeLa cells that constitutively synthesized the transactivator and that contained an appropriate, stably integrated reporter unit rapidly induced gene expression more than a thousandfold. The specificity of the Tet repressor-operator-effector interaction and the pharmacological characteristics of Tc's make this regulatory system well suited for the control of gene activities in vivo, such as in transgenic animals and possibly in gene therapy.

2,645 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231,122
20221,725
2021389
2020480
2019476
2018481