title: Mouse mammary tumor virus: specific methylation patterns of proviral DNA in normal mouse tissues.
abstract: The methylation state of endogenous mouse mammary tumor virus (MuMTV) proviral DNA was examined in normal mouse tissues. DNAs from various tissues were cleaved with the methylation-sensitive enzymes HhaI and HpaII and analyzed by Southern blotting. Tissue-specific MuMTV proviral DNA methylation patterns were found in the BALB/c, C3H, C57BL, GR/A, and GR-Mtv-2- mouse strains. MuMTV proviral DNA was hypomethylated in DNAs from the spleens and testes of all strains examined. The GR/A mouse strain, which was most thoroughly studied, also showed hypomethylation of MuMTV proviral DNA in bone marrow and placental tissues. Analysis of RNAs extracted from GR/A liver, mammary tumor, testes, placenta, and spleen tissues demonstrated that MuMTV proviral hypomethylation need not reflect significant proviral transcription.
mesh_terms: D002472:Cell Transformation, Viral; D002478:Cells, Cultured; D004279:DNA, Viral / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D005814:Genes, Viral; D008324:Mammary Tumor Virus, Mouse / Q000235:genetics*; D008745:Methylation; D012367:RNA, Viral / Q000235:genetics; D013154:Spleen / Q000382:microbiology; D013379:Substrate Specificity; D014158:Transcription, Genetic
chemical_list: D004279:DNA, Viral; D012367:RNA, Viral