title: Effect of vanadate on the chromatin configuration in pig GV-oocytes.
abstract: Vanadate, an inhibitor of tyrosine phosphatases, has been reported to prevent germinal vesicle breakdown in mammalian oocytes. We examined the effect of vanadate on the chromatin configuration of fully grown pig oocytes. In the presence of human menopausal gonadotropin (hMG), vanadate (0.5-5 mM) resulted in a dose-dependent change in oocyte chromatin in germinal vesicles from the condensed state to a decondensed filamentous or stringy configuration. The effect of vanadate and hMG on chromatin configuration could be replicated with 2 mM dibutyryl cyclic AMP (dbcAMP) in place of hMG. Western blot analysis showed that vanadate caused a massive accumulation in the oocytes of tyrosine-phosphorylated proteins with a range of molecular weights that was enhanced by both hMG and dbcAMP in a similar manner. These results suggest that inhibition of tyrosine phosphatase(s) in the presence of an effective level of cAMP induces a change in chromatin configuration of pig oocytes.
authors.affiliation: Department of Animal Biotechnology, College of Animal Bioscience & Biotechnology, Konkuk University, Seoul, Korea. bthuy@konkuk.ac.kr
authors.forename: Hong-Thuy
authors.initials: HT
authors.lastname: Bui
authors.forename: Kyu-Chan
authors.initials: KC
authors.lastname: Hwang
authors.forename: Jin-Hoi
authors.initials: JH
authors.lastname: Kim
authors.forename: Nguyen
authors.initials: N
authors.lastname: Van Thuan
authors.forename: Teruhiko
authors.initials: T
authors.lastname: Wakayama
authors.forename: Takashi
authors.initials: T
authors.lastname: Miyano
mesh_terms: D000818:Animals; D003994:Bucladesine / Q000378:metabolism; D002454:Cell Differentiation; D002843:Chromatin / Q000737:chemistry* / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000494:pharmacology; D006062:Gonadotropins / Q000378:metabolism; D006801:Humans; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry; D013552:Swine; D013997:Time Factors; D014443:Tyrosine / Q000737:chemistry; D014638:Vanadates / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D002843:Chromatin; D004791:Enzyme Inhibitors; D006062:Gonadotropins; D014638:Vanadates; D014443:Tyrosine; D003994:Bucladesine; D000242:Cyclic AMP; D010744:Phosphoric Monoester Hydrolases