Polyspermic mouse eggs can dispose of supernumerary sperm☆
[摘要] Zona-freemouseeggsinseminatedwithcapacitatedepididymalsperminamodifiedKrebs-Ringerbicarbonatemediumexhibitedunusualkineticsofspermincorporation.Ataspermconcentrationof105cells/mlorhigher,themeannumberofspermpereggreachedamaximumandthendecreasedwithtime.Thisdecreasewascorrelatedwiththeabstrictionofspermincytoplasmicblebswhichformedduringorslightlyaftersecondpolarbodyabstriction,1.5–2.5hrpostinsemination.Acorrelationwasapparentbetweenthedegreeofpolyspermyandthetotalnumberofspermlostbythismechanism.Of82dispermiceggsstudied,36underwentspermlossbyblebbing,aprocessthatrestoredthemonospermiccondition.Thesequentialstepsintheabstrictionprocessaredepictedinmicrographsofwholemountsoffixedeggs.Aspermheadormalepronucleuscouldbeseeninisolatedblebs.ThepreventionofblebformationbyexposureofpenetratedeggstocytochalasinBlargelyeliminatedanydifferenceinspermnumberwhenthemeannumberofspermpereggwascomparedat2,4,and6hrpostinsemination.Spermabstrictionmaybeanovelspermexclusionmechanismemployedbymammalianeggs.Evidenceisalsopresentedthatanunknownmechanismofspermexclusionisoperativeinmouseeggs,sincespermlossbyabstrictiondidnotaccountforallspermloss.
[发布日期] [发布机构]
[效力级别] [学科分类] 生物科学（综合）
[关键词] [时效性]
