Cytoplasmic polyadenylation controls cdc25B mRNA translation in rat oocytes resuming meiosis.
Resumption of meiosis in oocytes represents the entry into M-phase of the cell cycle and is regulated by the maturation-promoting factor (MPF). Activation of MPF is catalyzed by the dual specificity phosphatase, cdc25. In mammals, cdc25 is represented by a multigene family consisting of three isoforms: A, B and C. A recent report that female mice lacking cdc25B exhibit impaired fertility suggests a role for this isoform in regulating the G2- to M-transition in mammalian oocytes. Supporting the above-mentioned observation, we demonstrate herein that microinjection of neutralizing antibodies against cdc25B interfered with the ability of rat oocytes to undergo germinal vesicle breakdown (GVB). We also show accumulation of cdc25B in GVB oocytes and a transient reduction in its amount at metaphase I of meiosis. The accumulation of cdc25B was associated with its mRNA cytoplasmatic polyadenylation and was prevented by the protein synthesis inhibitor cyclohexamide as well as by the polyadenylation inhibitor cordycepin. Immunofluorescence staining revealed translocation of cdc25B to the metaphase II spindle apparatus. Taken together, our findings provide evidence that cdc25B is involved in resumption of meiosis in rat oocytes. We further demonstrate for the first time, a periodic accumulation of cdc25B throughout meiosis that is translationally regulated and involves cdc25B mRNA polyadenylation.
Gershon
Eran
E
Department of Biological Regulation, The Weizmann Institute of Science, Rehovot, 76100 Israel.
Galiani
Dalia
D
Dekel
Nava
N
D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D001692:Biological Transport; D015153:Blotting, Western / Q000379:methods; D018797:Cell Cycle Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D002478:Cells, Cultured; D003513:Cycloheximide / Q000494:pharmacology; D003593:Cytoplasm / Q000378:metabolism*; D003839:Deoxyadenosines / Q000494:pharmacology; D005260:Female; D005455:Fluorescent Antibody Technique; D007150:Immunohistochemistry / Q000379:methods; D016200:Maturation-Promoting Factor / Q000378:metabolism; D008540:Meiosis; D000090204:Mesothelin; D008845:Microinjections; D009865:Oocytes / Q000378:metabolism*; D026723:Polyadenylation / Q000187:drug effects; D014176:Protein Biosynthesis; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D008941:Spindle Apparatus / Q000378:metabolism; D020687:cdc25 Phosphatases / Q000235:genetics / Q000276:immunology / Q000378:metabolism
D000911:Antibodies, Monoclonal; D018797:Cell Cycle Proteins; D003839:Deoxyadenosines; C000715528:Msln protein, mouse; D011500:Protein Synthesis Inhibitors; D003513:Cycloheximide; D016200:Maturation-Promoting Factor; D020687:cdc25 Phosphatases; C058120:cordycepin; D000090204:Mesothelin