Evidence that the fertilization envelope blocks sperm entry in eggs of Xenopus laevis: Interaction of sperm with isolated envelopes☆
[摘要] ThecorticalreactionineggsofXenopuslaevisresultsinconversionofthevitellineenvelope(VE)intothefertilizationenvelope(FE).TheFEiscomposedoftheformerVEplusanewcomponent,thefertilizationlayer,thatformsasaconsequenceofthecorticalreaction.AninvitrotestsystemwasdevelopedtocomparetheVEandFEintermsoftheirpenetrabilitybysperm.VE'sandFE'swereisolatedfromunfertilizedeggsandcleavingembryos,respectively.Althoughtheyswellduringtheisolationprocedure,theisolatedVE'sandFE'sretainthemorphologicalcharacteristicsbywhichtheycanbedistinguishedinsitu.Penetrabilityofisolatedenvelopeswastestedbyexposingsuspensionsofenvelopestosperminasalinesolutiontowhichsolubilizedcomponentsfromthejellycoatoftheeggwereadded.IsolatedVE'swerepenetratedbyspermfrombothsides.Bycontrast,isolatedFE'sprovedimpenetrable:InnoinstancedidspermpenetrateeitherthefertilizationlayerortheVEcomponentoftheFE.WeconcludedthatthefertilizationenvelopeblocksspermentryinXenopuslaevis.
[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]
