Host genetic background effect on the frequency of mouse mammary tumor virus-induced rearrangements of the int-1 and int-2 loci in mouse mammary tumors.

AUTOR(ES)

Marchetti, A

RESUMO

The frequency with which int-1 and int-2 are rearranged in mouse mammary tumors by mouse mammary tumor virus (MMTV)-induced insertional mutagenesis is a consequence of the host genetic background. In 75% of C3H mammary tumors, int-1 is rearranged by MMTV insertion, whereas only 30% of BALB/cfC3H tumors contain a virus-induced rearrangement of int-1. This difference is significant (P less than 0.005) and could not be accounted for by the potentially additive effect of the genetically transmitted Mtv-1-encoded virus in C3H mice. Similarly, MMTV-induced rearrangement of the int-2 gene in mammary tumors of the R111 mouse strain (59%) occurred at a significantly (P less than 0.025) higher frequency than in BALB/cfR111 (25%) mammary tumors. Moreover, in BALB/cfR111 mammary tumors, there is evidence that rearrangement of int-1 and int-2 does not occur independently (P less than 0.025). These results suggest that the long history of inbreeding for high tumor incidence of C3H and R111 mouse strains has selected for the fixation of host mutations which either complement the action of the particular int gene or affect the sensitivity of specific subpopulations of mammary epithelium to infection by particular strains of MMTV.

Documentos Relacionados

• Expression of the int-1 and int-2 loci in endogenous mouse mammary tumor virus-induced mammary tumorigenesis in the C3Hf mouse.
• Mouse mammary tumor virus integration regions int-1 and int-2 map on different mouse chromosomes.
• Insertion mutation of the int-1 and int-2 loci by mouse mammary tumor virus in premalignant and malignant neoplasms from the GR mouse strain.
• Activation of int-1 and int-2 mammary oncogenes in hormone-dependent and -independent mammary tumors of GR mice.
• Genetics of Mouse Mammary Tumor Virus-Induced Mammary Tumors: Linkage of Tumor Induction to the gag Gene