title: Loss of proviral DNA sequences in a revertant of Kirsten sarcoma virus-transformed murine fibroblasts.
abstract: A previously described revertant cell line (K-BALB SR1212), derived as a single cell clone from a clonal line of murine fibroblasts (K-BALB) transformed by a nonproductive infection with the Kirsten strain of murine sarcoma virus, has normal morphology and growth kinetics and, unlike the transformed parent cell line, lacks a sarcoma virus that can be rescued. We report here that this reversion correlates with low to undetectable levels of expression of cellular Ki-MSV-specific RNA and a reduction of proviral sequences in the cell DNA to a level equivalent to that found in the uninfected BALB cells with a normal phenotype. The data indicate that phenotypic reversion has occurred as a consequence of the loss of part or all of the sarcoma provirus, either by chromosomal rearrangement or provirus excision.
mesh_terms: D000818:Animals; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D002472:Cell Transformation, Viral; D002999:Clone Cells; D004247:DNA / Q000032:analysis*; D004279:DNA, Viral / Q000032:analysis*; D005347:Fibroblasts; D007708:Kirsten murine sarcoma virus / Q000032:analysis*; D051379:Mice; D008807:Mice, Inbred BALB C; D009693:Nucleic Acid Hybridization; D012313:RNA / Q000032:analysis*; D012367:RNA, Viral / Q000032:analysis*; D009053:Sarcoma Viruses, Murine / Q000032:analysis*
chemical_list: D004279:DNA, Viral; D012367:RNA, Viral; D012313:RNA; D004247:DNA