Abstract
The induction of thymic lymphomas by Moloney murine leukemia virus
in the rat is linked to provirus integration in at least four independent
cellular DNA regions (Mlvi-1, Mlvi-2, Mlvi-3, and c-myc). Because
sequences homologous to at least three of these regions (Mlvi-1,
Mlvi-2, and c-myc) map to chromosome 15 in the mouse, the question
was raised whether they are closely linked in the rat genome and
whether provirus integration in any one of these regions affects
the same functional domain in rat DNA. In this study, we identified
the chromosomal map location of Mlvi-1, Mlvi-2, and Mlvi-3 in the
rat by using mouse-rat somatic cell hybrids that lose the rat chromosomes.
The results showed that Mlvi-1 maps similarly to c-myc to chromosome
7, and Mlvi-2 maps to chromosome 2. Mlvi-3 probably maps to chromosome
15. We conclude that Mlvi-1, Mlvi-2, and Mlvi-3 are separate and
independent genetic loci. Although Mlvi-1 and c-myc map to the same
chromosome, they are not related, as determined by hybridization
and restriction endonuclease mapping. The chromosomal map location
of Mlvi-1 to chromosome 7 and Mlvi-2 to chromosome 2 is interesting,
since chromosomal aberrations involving these two chromosomes are
reproducibly observed in rat neoplasias induced by a variety of agents.
Users
Please
log in to take part in the discussion (add own reviews or comments).