title: Estrogen withdrawal in chick oviduct. Evidence for continued expression of active unique genes using an "expressed" DNA probe.
abstract: We have analyzed the effect of estrogen on the kinds of unique DNA sequences which are transcriptionally expressed in chick oviduct with an "expressed" DNA probe. Steady-state nRNA in estrogen-stimulated chick oviduct represents about 25% of the complexity of total chick unique DNA. To purify this expressed DNA fraction, chick unique DNA was isolated, nick-translated, and hybridized to chemically mercurated oviduct nRNA (Hg-nRNA); the resulting hybrids were bound to sulfhydryl-Sepharose, and DNA was selectively recovered by thermal elution in formamide buffer. To compare the sequence homology between nRNAs isolated from oviduct before or up to 6 days after estrogen withdrawal, trace amounts of expressed DNA derived from estrogen-stimulated oviduct were hybridized in RNA-excess reactions. All nRNAs hybridized with equal efficiency. Furthermore, hybridization of expressed DNA to nRNA mixtures showed that nRNA from nonwithdrawn and withdrawn oviduct contained a similar set of unique sequences. The data indicate that, at most, only a small percentage (0--5%) of transcriptionally active unique DNA sequences are shut down when estrogen is removed from the circulation.
mesh_terms: D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D002645:Chickens; D004247:DNA / Q000378:metabolism*; D004355:Drug Stability; D005260:Female; D005796:Genes; D006589:Hexestrol / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D009693:Nucleic Acid Hybridization; D009695:Nucleic Acid Renaturation; D010057:Oviducts / Q000187:drug effects / Q000378:metabolism*; D014176:Protein Biosynthesis; D012313:RNA / Q000378:metabolism; D013375:Substance Withdrawal Syndrome; D013696:Temperature; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D006589:Hexestrol; D012313:RNA; D004247:DNA