title: Two mechanisms for the extinction of gene expression in hybrid cells.
abstract: When two different mammalian cell types are fused to generate a stable hybrid cell line, genes that are active in only one of the parents are frequently shut off, a phenomenon called extinction. In this study two distinct, complementary mechanisms for such extinction of growth hormone gene expression were identified. In hybrids formed by fusing fibroblasts to pituitary cells, pituitary-specific proteins that bind to the growth hormone promoter were absent. In addition, a negative regulatory element located near the rat growth hormone promoter was specifically activated.
authors.affiliation: Department of Molecular Biology, Massachusetts General Hospital, Boston.
authors.forename: P
authors.initials: P
authors.lastname: Tripputi
authors.forename: S L
authors.initials: SL
authors.lastname: Guérin
authors.forename: D D
authors.initials: DD
authors.lastname: Moore
mesh_terms: D000123:Acetyltransferases / Q000235:genetics; D000818:Animals; D001358:Avian Sarcoma Viruses / Q000235:genetics; D015500:Chloramphenicol O-Acetyltransferase; D004742:Enhancer Elements, Genetic; D005347:Fibroblasts / Q000378:metabolism; D005786:Gene Expression Regulation; D013006:Growth Hormone / Q000235:genetics*; D006564:Herpesviridae / Q000235:genetics; D006822:Hybrid Cells / Q000378:metabolism*; D007041:Hypoxanthine Phosphoribosyltransferase / Q000235:genetics; D007739:L Cells; D051379:Mice; D010902:Pituitary Gland / Q000378:metabolism; D010957:Plasmids; D011401:Promoter Regions, Genetic; D051381:Rats; D013937:Thymidine Kinase / Q000235:genetics; D014162:Transfection
chemical_list: D013006:Growth Hormone; D000123:Acetyltransferases; D015500:Chloramphenicol O-Acetyltransferase; D007041:Hypoxanthine Phosphoribosyltransferase; D013937:Thymidine Kinase