Martin Leslie Hooper

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Human retinoblastomas can occur both as hereditary and as sporadic cases. Knudson's proposal that they result from two mutational events, of which one is present in the germ line in hereditary cases, has been confirmed by more recent molecular analysis, which has shown both events to involve loss or mutational inactivation of the same gene, RB-1 (ref. 2).(More)
The neural membrane glycoprotein PrP is implicated in the pathogenesis of the transmissible spongiform encephalopathies; however, the normal function of PrP and its precise role in disease are not understood. Recently, gene targeting has been used to produce mice withneo/PrP fusion transcripts, but no detectable PrP protein in the brain (1). Here we report(More)
Death by apoptosis is characteristic of cells undergoing deletion during embryonic development, T- and B-cell maturation and endocrine-induced atrophy. Apoptosis can be initiated by various agents and may be a result of expression of the oncosuppressor gene p53 (refs 6-8). Here we study the dependence of apoptosis on p53 expression in cells from the thymus(More)
Many pluripotent embryonal carcinoma (EC) cell lines and all embryonic stem (ES) cell lines have hitherto been maintained in the undifferentiated state only by culture on feeder layers of mitomycin C-treated embryonic fibroblasts. We now demonstrate that medium conditioned by incubation with Buffalo rat liver (BRL) cells prevents the spontaneous(More)
Analysis of mice carrying mutant T-cell antigen receptor (TCR) genes indicates that TCR-beta gene rearrangement or expression is critical for the differentiation of CD4-CD8- thymocytes to CD4+CD8+ thymocytes, as well as for the expansion of the pool of CD4+CD8+ cells. TCR-alpha is irrelevant in these developmental processes. The development of gamma delta T(More)
Two recent developments suggest a route to predetermined alterations in mammalian germlines. These are, first, the characterization of mouse embryonic stem (ES) cells that can still enter the germline after genetic manipulation in culture and second, the demonstration that homologous recombination between a native target chromosomal gene and exogenous DAN(More)
Cystic fibrosis is a fatal genetic disorder which afflicts 50,000 people worldwide. A viable animal model would be invaluable for investigating and combating this disease. The mouse cystic fibrosis transmembrane conductance regulator gene was disrupted in embryonal stem cells using an insertional gene targeting vector. Germ-line chimaeras were derived and(More)
The Wilms tumor-suppressor gene, WT1, plays a key role in urogenital development, and WT1 dysfunction is implicated in both neoplastic (Wilms tumor, mesothelioma, leukemias, and breast cancer) and nonneoplastic (glomerulosclerosis) disease. The analysis of diseases linked specifically with WT1 mutations, such as Denys-Drash syndrome (DDS), can provide(More)
Specific genes can be inactivated or mutated in the mouse germ line. The phenotypic consequences of the mutation can provide pivotal information on the function of the gene in development and maintenance of the mammalian organism. The procedure entails homologous recombination in embryonic stem cells, which, on fusion to recipient blastocysts, give rise to(More)
Defects of mismatch repair are thought to be responsible for carcinogenesis in hereditary non-polyposis colorectal cancer and about 15% of sporadic colon cancers. The phenotype is seen as microsatellite instability and is known to be caused either by mutations in mismatch repair genes or by aberrant methylation of these genes stabilizing their(More)