title: Mobilization of Dormant Cnot7 mRNA Promotes Deadenylation of Maternal Transcripts During Mouse Oocyte Maturation.
abstract: Maternal mRNAs in oocytes are remarkably stable. In mouse, oocyte maturation triggers a transition from mRNA stability to instability. This transition is a critical event in the oocyte-to-embryo transition in which a differentiated oocyte loses its identity as it is transformed into totipotent blastomeres. We previously demonstrated that phosphorylation of MSY2, an RNA-binding protein, and mobilization of mRNAs encoding the DCP1A-DCP2 decapping complex contribute to maternal mRNA destruction during meiotic maturation. We report here that Cnot7, Cnot6l, and Pan2, key components of deadenylation machinery, are also dormant maternal mRNAs that are recruited during oocyte maturation. Inhibiting the maturation-associated increase in CNOT7 (or CNOT6L) using a small interference RNA approach inhibits mRNA deadenylation, whereas inhibiting the increase in PAN2 has little effect. Reciprocally, expressing CNOT7 (or CNOT6L) in oocytes prevented from resuming meiosis initiates deadenylation of mRNAs. These effects on deadenylation are also observed when the total amount of poly (A) is quantified. Last, inhibiting the increase in CNOT7 protein results in an ~70% decrease in transcription in 2-cell embryos.
authors.affiliation: Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Jun
authors.initials: J
authors.lastname: Ma
authors.affiliation: Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Fukuda
authors.affiliation: Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania rschultz@sas.upenn.edu.
authors.forename: Richard M
authors.initials: RM
authors.lastname: Schultz
mesh_terms: D000225:Adenine / Q000378:metabolism*; D000818:Animals; D001757:Blastomeres / Q000502:physiology; D004247:DNA / Q000235:genetics; D004622:Embryo, Mammalian / Q000378:metabolism; D005095:Exoribonucleases; D005260:Female; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D016678:Genome / Q000235:genetics; D008540:Meiosis / Q000235:genetics; D051379:Mice; D009865:Oocytes / Q000502:physiology*; D011061:Poly A / Q000378:metabolism; D011247:Pregnancy; D011506:Proteins / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics; D012097:Repressor Proteins; D012260:Ribonucleases / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics
chemical_list: D011506:Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; C116047:Ybx2 protein, mouse; D011061:Poly A; D004247:DNA; C521731:Cnot6l protein, mouse; C489778:Cnot7 protein, mouse; D005095:Exoribonucleases; D012260:Ribonucleases; D000225:Adenine
keywords: CNOT6L; CNOT7; PAN2; deadenylase; early development; gamete biology; mRNA degradation; maternal recruited mRNA; oocyte maturation