Mobilization of Dormant Cnot7 mRNA Promotes Deadenylation of Maternal Transcripts During Mouse Oocyte Maturation.
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.
['Ma|Jun|J|', 'Fukuda|Yusuke|Y|', 'Schultz|Richard M|RM|']
D000225:Adenine D000818:Animals D001757:Blastomeres D004247:DNA D004622:Embryo, Mammalian D005095:Exoribonucleases D005260:Female D018507:Gene Expression Regulation, Developmental D055785:Gene Knockdown Techniques D016678:Genome D008540:Meiosis D051379:Mice D009865:Oocytes D011061:Poly A D011247:Pregnancy D011506:Proteins D012333:RNA, Messenger D016601:RNA-Binding Proteins D012097:Repressor Proteins D012260:Ribonucleases D014158:Transcription, Genetic
CNOT7 oocyte maturation CNOT6L PAN2 deadenylase early development gamete biology mRNA degradation maternal recruited mRNA