title: An essential role for the intra-oocyte MAPK activity in the NSN-to-SN transition of germinal vesicle chromatin configuration in porcine oocytes.
abstract: The mechanisms for the transition from non-surrounded nucleolus (NSN) to surrounded nucleolus (SN) chromatin configuration during oocyte growth/maturation are unclear. By manipulating enzyme activities and measuring important molecules using small-follicle pig oocytes with a high proportion of NSN configuration and an extended germinal vesicle stage in vitro, this study has the first time up-to-date established the essential role for intra-oocyte mitogen-activated protein kinase (MAPK) in the NSN-to-SN transition. Within the oocyte in 1-2 mm follicles, a cAMP decline activates MAPK, which prevents the NSN-to-SN transition by activating nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) while inhibiting histone deacetylase (HDAC). In cumulus cells of 1-2 mm follicles, a lower level of estradiol and oocyte-derived paracrine factor (ODPF) reduces natriuretic peptide receptor 2 (NPR2) while enhancing FSH and cAMP actions. FSH elevates cAMP levels, which decreases NPR2 while activating MAPK. MAPK closes the gap junctions, which, together with the NPR2 decrease, reduces cyclic guanosine monophosphate (cGMP) delivery leading to the cAMP decline within oocytes. In 3-6 mm follicles, a higher level of estradiol and ODPF and a FSH shortage initiate a reversion of the above events leading to MAPK inactivation and NSN-to-SN transition within oocytes.
authors.affiliation: College of Life Science, Northeast Agricultural University, Harbin, 150030, P.R. China.
authors.forename: Ming-Ju
authors.initials: MJ
authors.lastname: Sun
authors.affiliation: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City 271018, P.R. China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Zhu
authors.affiliation: College of Life Science, Northeast Agricultural University, Harbin, 150030, P.R. China.
authors.forename: You-Wei
authors.initials: YW
authors.lastname: Li
authors.affiliation: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City 271018, P.R. China.
authors.forename: Juan
authors.initials: J
authors.lastname: Lin
authors.affiliation: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City 271018, P.R. China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Gong
authors.affiliation: College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City 271018, P.R. China.
authors.forename: Guang-Zhong
authors.initials: GZ
authors.lastname: Jiao
authors.affiliation: College of Life Science, Northeast Agricultural University, Harbin, 150030, P.R. China.
authors.forename: Fei
authors.initials: F
authors.lastname: Chen
authors.affiliation: College of Life Science, Northeast Agricultural University, Harbin, 150030, P.R. China.|College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City 271018, P.R. China.
authors.forename: Jing-He
authors.initials: JH
authors.lastname: Tan
mesh_terms: D000818:Animals; D002466:Cell Nucleolus / Q000378:metabolism*; D002843:Chromatin / Q000378:metabolism*; D004958:Estradiol / Q000378:metabolism; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D005786:Gene Expression Regulation; D006655:Histone Deacetylases / Q000378:metabolism; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism; D009865:Oocytes / Q000166:cytology* / Q000378:metabolism*; D009866:Oogenesis; D013552:Swine
chemical_list: D002843:Chromatin; D016328:NF-kappa B; D004958:Estradiol; D005640:Follicle Stimulating Hormone; D020929:Mitogen-Activated Protein Kinase Kinases; D006655:Histone Deacetylases