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Biomedical subjects

D D Myers

Publications and source records attributed to D D Myers.

28 records · Page 2Linked to original sources
PubMed1970

Group-specific antigen expression during embryogenesis of the genome of the C-type RNA tumor virus: implications for ontogenesis and oncogenesis.

Tests for the group-specific antigen of the C-type RNA tumor virus showed that mouse embryos of all strains tested, at some stage of development in utero, revealed detectable titers of group-specific antigen in one or more of their tissues; younger, rather than older, embryos were likely to be positive, particularly in those strains which normally reveal little or no expression of the RNA genome postnatally. The antigens were found in embryos of low-leukemia strains, free of infectious virus. These new findings support a previously stated hypothesis that the genome of RNA tumor viruses, mostly switched off for infectious virus expression, is vertically transmitted as part of the natural genetic apparatus of normal mouse cells. Since group-specific antigens have also been described in chick embryos and immunological tolerance to homologous group-specific antigens has been demonstrated in hamsters and cats as well as in mice and chickens, the hypothesis has been extended to include vertebrate cells in general. Finally, the high incidence and titers of the group-specific antigen suggest that the genes for RNA tumor virus, which later in life act as determinants of cancer, may be important also as gene determinants in the developing embryo.

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PubMed1969

Genetic control by the hr-locus of susceptibility and resistance to leukemia.

Leukemia was observed in 45 per cent of hairless mice at 8 to 10 months of age and 72 per cent at 18 months. The incidence of leukemia in normal heterozygous mice of the same age is about one per cent at 10 months and increases to 20 per cent at 18 months. Other tumors are rare; two mammary adenocarcinomas occurred in heterozygotes, and an epidermal squamous cell carcinoma was found in a hairless mouse. Murine leukemia virus was isolated from normal and leukemic mice of both genotypes on SWR/J- and C57L/J-METC, but not BALB/cJ-METC. If this virus is responsible for the leukemia in HRS/J mice, the mutant gene (hr) enhances susceptibility and the wild-type allele (+) induces resistance to leukemogenesis, i.e., malignant transformation of reticulo-endothelial tissues occurs rather than inhibition of viral replication as both genotypes harbor virus in high titers. The two types of HRS/J mice, hr/hr and hr/+, are congenic, i.e., they differ only with respect to one allele (hr or +) at the mutant locus. This single gene difference should lend itself to analysis of the interaction of a specific gene and murine leukemia virus.

Animals↗
PubMedDate not supplied

Myodystrophy, a new myopathy on chromosome 8 of the mouse.

A new recessive mutation, myd, causing a diffuse and progressive myopathy in the mouse is described. Histopathological comparisons with normal littermates showed widely distributed focal lesions in all skeletal muscles of myd/myd. Body and organ weights of affected mice were considerably less than those of normal littermates and the mean lifespan of myodystrophic mice that survived weaning was 17 weeks with a range of 5 to 39 weeks. Myodystrophy is located on chromosome 8; it is linked to Os with about 6 percent and to Eso with about 37 percent recombination.

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