Analysis of the Genomes of Mink Cell Focus-inducing Murine Type-C Viruses: A Progress Report (original) (raw)

1. M. L. Lung,
2. C. Hering,
3. J. W. Hartley*,
4. W. P. Rowe*, and
5. N. Hopkins
6. Center for Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139;*National Institutes of Health, Bethesda, Maryland 20014

Excerpt

Inbred strains of mice that exhibit a high incidence of spontaneous lymphoma are characterized by high titers of infectious ecotropic C-type retroviruses, murine leukemia viruses (MuLVs), in their tissues from soon after birth throughout life (see Rowe 1977). The high-virus phenotype results from expression of inherited DNA copies of ecotropic MuLVs followed by efficient horizontal spread of virus within the animal.

Despite compelling evidence that the lifelong expression of ecotropic virus is a necessary factor in the development of spontaneous lymphomas of high-leukemic mice (Lilly et al. 1975; Rowe 1977), other lines of evidence have suggested that these viruses are not themselves capable of transforming lymphocytes to malignancy in their hosts. In particular, extracts of thymus from young and old preleukemic or leukemic AKR mice contain essentially equal titers of ecotropic virus, but only the extracts from old mice are leukemogenic following injection into newborn mice (Kaplan 1967; Nishizuka and...