title: Effects of divalent cations on in vitro maturation of bovine oocytes.
abstract: Lowering the external concentrations of both Mg+2 and Ca+2 caused failure of meiotic resumption in vitro of bovine, oocyte-cumulus complexes. Lowering of external Ca+2 levels singly had no effect on either meiotic resumption or completion of the first meiotic division. Lowering of external Mg+2 concentrations alone, although having no effect on meiotic resumption in vitro when Ca+2 was present, did interfere with the completion of the first meiotic division. The result was arrest of oocyte maturation between germinal vesicle breakdown and formation of the first metaphase plate.
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002417:Cattle; D003470:Culture Media; D005260:Female; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology*; D008540:Meiosis / Q000187:drug effects; D009865:Oocytes / Q000187:drug effects* / Q000254:growth & development; D010063:Ovum / Q000187:drug effects*
chemical_list: D003470:Culture Media; D008274:Magnesium; D002118:Calcium