title: Greatwall kinase is required for meiotic maturation in porcine oocytes.
abstract: Meiotic maturation in many species is initiated by the activation of maturation-promoting factor (MPF) with concomitant inactivation of counteracting phosphatases, most notably protein phosphatase 2A (PP2A). Recently, Greatwall (GWL) has been identified as a cell cycle regulator that inhibits PP2A activity. In this study, we demonstrate that GWL is required for meiotic maturation in porcine oocytes. GWL expression increases from germinal vesicle (GV) to metaphase II (MII) stages of porcine oocytes and dramatically decreases with progression of the meiotic cell cycle. GWL is initially localized in the nucleus of GV oocytes and is associated with spindle fibers following GV breakdown. Depletion of GWL inhibited or delayed meiotic maturation secondary to defects in chromosome congression and spindle formation. Conversely, overexpression of GWL overcame meiotic arrest and initiated progression to MII stage. However, these oocytes had severe spindle defects. Furthermore, MII oocytes depleted of GWL progressed to pronuclear formation. Taken together, our data demonstrate that GWL is required not only for meiotic maturation but also for maintenance of MII arrest in porcine oocytes.
authors.affiliation: Department of Animal Sciences, Chungbuk National University, Cheongju, Korea.
authors.forename: Ying-Hua
authors.initials: YH
authors.lastname: Li
authors.forename: Hyoeun
authors.initials: H
authors.lastname: Kang
authors.forename: Yong-Nan
authors.initials: YN
authors.lastname: Xu
authors.forename: Young-Tae
authors.initials: YT
authors.lastname: Heo
authors.forename: Xiang-Shun
authors.initials: XS
authors.lastname: Cui
authors.forename: Nam-Hyung
authors.initials: NH
authors.lastname: Kim
authors.forename: Jeong Su
authors.initials: JS
authors.lastname: Oh
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D003001:Cloning, Molecular; D005260:Female; D055785:Gene Knockdown Techniques; D059471:In Vitro Oocyte Maturation Techniques / Q000662:veterinary; D008540:Meiosis / Q000235:genetics*; D000090204:Mesothelin; D051379:Mice; D008810:Mice, Inbred C57BL; D009865:Oocytes / Q000502:physiology*; D009866:Oogenesis / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000302:isolation & purification / Q000502:physiology*; D013552:Swine / Q000235:genetics / Q000378:metabolism
chemical_list: C000715528:Msln protein, mouse; D017346:Protein Serine-Threonine Kinases; D000090204:Mesothelin
keywords: GWL; Greatwall; MPF; PP2A; cell cycle; meiosis; meiotic arrest; meiotic maturation; oocyte; oocyte maturation