title: Carrying-over effects of GVBD blocking on post-blocking meiotic progression of oocytes: species difference and the signaling pathway leading to MPF activation.
abstract: Efforts to improve the quality of in vitro matured oocytes by blocking germinal vesicle breakdown (GVBD) and allowing more time for ooplasmic maturation have achieved little due to a lack of knowledge on the molecular events during GVBD blocking. Such knowledge is also important for studies aimed at regulating gene expression in maturing oocytes prior to GVBD. We studied species difference and signaling pathways leading to the carrying-over effect of GVBD blocking on post-blocking meiotic progression (PBMP). Overall, GVBD-blocking with roscovitine decelerated PBMP of mouse oocytes but accelerated that of pig oocytes. During blocking culture, whereas cyclin B of pig oocytes increased continuously, that of mouse oocytes declined first and then increased slowly. In both species, (a) whereas active CDC2A showed a dynamics similar to cyclin B, inactive CDC2A decreased continuously; (b) when oocytes were blocked in blocking medium containing cycloheximide, PBMP was decelerated significantly while cyclin B and active CDC2A decreasing to the lowest level; (c) whereas sodium vanadate in blocking medium reduced PBMP, epidermal growth factor (EGF) in blocking medium accelerated PBMP significantly with no effect on cyclin B levels. In conclusion, the EGF signaling cascade accelerated PBMP by promoting the pre-MPF (M-phase-promoting factor) to MPF conversion during GVBD blocking with roscovitine. The significant difference in PBMP observed between mouse and pig oocytes was caused by species difference in cyclin B dynamics during blocking culture as no species difference was observed in either pre-MPF to MPF conversion or the EGF signaling activity.
authors: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P. R. China.
authors: Guang-Zhong
authors: GZ
authors: Jiao
authors: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P. R. China.
authors: Hua-Yu
authors: HY
authors: Lian
authors: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P. R. China.
authors: Yan
authors: Y
authors: Gao
authors: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P. R. China.
authors: Ming-Ju
authors: MJ
authors: Sun
authors: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P. R. China.
authors: Shuai
authors: S
authors: Gong
authors: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P. R. China.
authors: Liang-Liang
authors: LL
authors: Zheng
authors: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P. R. China.
authors: Chuan-Xin
authors: CX
authors: Zhang
authors: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City, P. R. China.
authors: Jing-He
authors: JH
authors: Tan
mesh_terms: D000818:Animals; D018797:Cell Cycle Proteins / Q000378:metabolism; D002478:Cells, Cultured; D005260:Female; D016200:Maturation-Promoting Factor / Q000378:metabolism*; D008540:Meiosis; D000090204:Mesothelin; D051379:Mice; D009865:Oocytes / Q000502:physiology*; D011498:Protein Precursors / Q000378:metabolism*; D011687:Purines / Q000494:pharmacology; D000077546:Roscovitine; D015398:Signal Transduction; D013045:Species Specificity; D034421:Sus scrofa
chemical_list: D018797:Cell Cycle Proteins; C000715528:Msln protein, mouse; D011498:Protein Precursors; D011687:Purines; C067034:maturation-promoting factor precursor; D000077546:Roscovitine; D016200:Maturation-Promoting Factor; D000090204:Mesothelin