title: Changes in signal molecules and maturation promoting factor levels associate with spontaneous resumption of meiosis in rat oocytes.
abstract: The present study was aimed to find out changes in signal molecules and maturation promoting factor (MPF) levels during meiotic cell cycle progression from diplotene and metaphase-II (M-II) arrest, a period during which oocyte achieves meiotic competency. Data suggest that high levels of adenosine 3'-5'-cyclic monophosphate (cAMP), guanosine 3'-5'-cyclic monophosphate (cGMP), and nitric oxide (NO) are associated with diplotene arrest, while reduction in their levels correlates with reduced MPF level and meiotic resumption from diplotene arrest. On the other hand, increased intracellular NO, calcium (Ca(2+) ) as well as hydrogen peroxide (H2 O2 ) levels correlate with decreased cAMP, Thr-161 phosphorylated cyclin-dependent kinase-1 (Cdk1) as well as cyclin B1 levels. The decreased Thr-161 phosphorylated Cdk1 and cyclin B1 level reduce MPF level leading to exit from M-II arrest in oocytes cultured in vitro. These data suggest that the decrease of cAMP level and increase of cytosolic free Ca(2+) as well as H2 O2 levels associate with the reduced MPF level and meiotic resumption from diplotene arrest. On the other hand, increase of NO, cGMP, Ca(2+) as well as H2 O2 levels are associated with reduced MPF and spontaneous exit from M-II arrest in rat oocytes cultured in vitro.
authors.affiliation: Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India.
authors.forename: Shilpa
authors.initials: S
authors.lastname: Prasad
authors.affiliation: Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India.
authors.forename: Meenakshi
authors.initials: M
authors.lastname: Tiwari
authors.affiliation: Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India.
authors.forename: Anima
authors.initials: A
authors.lastname: Tripathi
authors.affiliation: Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India.
authors.forename: Ashutosh N
authors.initials: AN
authors.lastname: Pandey
authors.affiliation: Cell Physiology Laboratory, Biochemistry Unit, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India.
authors.forename: Shail K
authors.initials: SK
authors.lastname: Chaube
mesh_terms: D000818:Animals; D016203:CDC2 Protein Kinase / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D048430:Cell Shape; D033481:Chromosomes, Mammalian / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D056744:Cyclin B1 / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D005260:Female; D005453:Fluorescence; D006861:Hydrogen Peroxide / Q000378:metabolism; D016200:Maturation-Promoting Factor / Q000378:metabolism*; D008540:Meiosis; D009569:Nitric Oxide / Q000378:metabolism; D009573:Nitrites / Q000378:metabolism; D009865:Oocytes / Q000166:cytology* / Q000378:metabolism*; D010766:Phosphorylation; D010769:Phosphothreonine / Q000378:metabolism; D051381:Rats; D015398:Signal Transduction
chemical_list: D056744:Cyclin B1; D009573:Nitrites; D010769:Phosphothreonine; D009569:Nitric Oxide; D006861:Hydrogen Peroxide; D000242:Cyclic AMP; D016203:CDC2 Protein Kinase; D016200:Maturation-Promoting Factor; D006152:Cyclic GMP; D002118:Calcium
keywords: Cdk1; cyclin B1; meiotic cell cycle; rat oocyte; signal molecules