title: Increased abundance of a normal cell mRNA sequence accompanies the conversion of rat mammary cuboidal epithelial cells to elongated myoepithelial-like cells in culture.
abstract: Rat mammary cuboidal epithelial cell lines in culture convert to elongated myoepithelial-like cells. This conversion is accompanied by the appearance of a 9,000 molecular weight acidic polypeptide (p9ka), abundant in the elongated convertants, but which is hardly detectable in the cuboidal epithelial cells. A cDNA library corresponding to a low-molecular-weight fraction of poly(A)- containing RNA from a myoepithelial-like cell line, has been constructed. Recombinant plasmids containing cDNA complementary to p9ka mRNA have been identified by hybrid-selected translation. The mRNA for p9ka has been identified by Northern blotting and is found to be at least five-times more abundant in cultured myoepithelial-like rat mammary cells when compared to the cuboidal epithelial cells. This cytoplasmic mRNA sequence, which is present in increased abundance in cultured mammary myoepithelial-like cells, is also present, at lower levels, in normal rat tissues, including the mammary glands.
mesh_terms: D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D004247:DNA / Q000378:metabolism; D004262:DNA Restriction Enzymes; D004847:Epithelial Cells; D008321:Mammary Glands, Animal / Q000166:cytology*; D008649:Mesonephroma; D008970:Molecular Weight; D009693:Nucleic Acid Hybridization; D010455:Peptides / Q000235:genetics; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics* / Q000302:isolation & purification; D051381:Rats
chemical_list: D010455:Peptides; D012333:RNA, Messenger; D004247:DNA; D004262:DNA Restriction Enzymes