title: [Expression of MMTV proviruses in lymphopoietic organs of C3H Bi mice].
abstract: We show that transcription of MMTV proviruses takes place in lymphopoietic tissues (spleen, thymus) of C3H Bi mice, a strain with high incidence of tumors. This transcription is found in the spleen of 21 day old mice but is no longer detectable in the spleen of 4 month old mice. In the mammary tumor, the 3.8 kb RNA (24S) which encodes the viral envelope proteins is well transcribed whereas the 1.7 kb RNA (13 S) is barely detectable. In contrast, the 1.7 kb (13 S) is the major species present in the spleen of 21 day old mice. It appears that the 7.8 kb genomic RNA (35 S) is differentially spliced into a mature RNA of either 3.8 kb (24 S) or 1.7 kb (13 S). The function of the latter is still unknown, though it could encode a protein involved in the induction of carcinogenesis.
mesh_terms: D000818:Animals; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics*; D051379:Mice; D008809:Mice, Inbred C3H; D012367:RNA, Viral / Q000032:analysis; D013154:Spleen / Q000382:microbiology*; D013950:Thymus Gland / Q000382:microbiology*; D013997:Time Factors; D014158:Transcription, Genetic
chemical_list: D012367:RNA, Viral
vernacular_title: Expression des provirus MMTV dans les organes lymphopoiétiques de souris C3H Bi.