Mammalian Oocyte Activation by the Synergistic Action of Discrete Sperm Head Components: Induction of Calcium Transients and Involvement of Proteolysis

Developmental Biology

Anthony C.F. Perry¹  Ryuzo Yanagimachi¹  Teruhiko Wakayama¹  Ian M. Cooke¹ 

[1] Laboratory of Vertebrate Developmental Neurogenetics, Rockefeller University, 1230 York Avenue, Box 242, New York, New York, 10021-6399

关键词: oocyte activation;    mouse;    sperm;    calcium;    proteolysis;   

DOI  :  10.1006/dbio.1999.9552

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

Sperm-borneoocyte-activatingfactor(SOAF)elicitsactivationsufficientforfulldevelopmentandoriginatesfromspermheadsubmembranematrices.SOAFcomprisesdiscrete,heat-sensitiveand-stablecomponents(referredtohererespectivelyasSOAF-Iand-II)whichareeachnecessarybutnotsufficienttoactivateoocytes.Theheat-sensitiveSOAFcomponent,SOAF-Im,becomessolubilizedfromtheperinuclearmatrixunderreducingconditions(theSOAFtransition)togenerateSOAF-Is.Althoughcalciumtransientslikelyplayanimportantroleinoocyteactivationatfertilization,thequestionisopenastowhetherdemembranatedheadsorSOAF-Isand/orSOAF-IIcaninducecalciumtransients.WenowreportthatinjectionofdemembranatedspermheadsintomouseoocytesefficientlyinducedCa2+oscillations.Wheninjectedindependently,SOAF-Isanddemembranatedheadsheatedto48°CfailedtogenerateCa2+oscillations.However,co-injectionofSOAF-Isand48°C-heatedheadsinducedoscillations,mirroringtheirsynergisticabilitytoactivateoocytes.ThissuggeststhatSOAF-mediatedactivationproceedsviapathwaysresemblingthoseatfertilizationandprovidesthefirstdirectevidencethatmultiplespermcomponentsarerequiredtoinduceCa2+oscillations.WeprobedtheSOAF-Isliberationatthecenterofthisactivationandshowthatinvitroitwassensitivetoaprofileofserineproteaseinhibitors.Thesefindingssupportamodelinwhichmammalianoocyteactivation,includingtheinductionofcalciumtransients,involvesproteolyticprocessingofSOAFfromspermheadsubmembranecompartments.

【 授权许可】

Unknown