Hatching in the toad Xenopus laevis: Morphological events and evidence for a hatching enzyme☆
[摘要] ThehatchingprocessinembryosofthetoadXenopuslaevisconsistsoftwotemporallydistinctphases.Inphase1,theembryoescapessequentiallyfromthetwooutermostjellylayers,J3andJ2,andduringphase2theembryohatchesfromthelastremainingjellycoatlayerJ1andthefertilizationenvelope.Phase1hatchingappearstobeaphysicalprocesscausedbywaterinbibitionofjellycoatlayerJ1anddynamicchangesinthevolumeenclosedbythefertilizationenvelope.ThecombinedturgorpressurerupturesjellycoatlayersJ3andJ2.Thesubsequentphase2hatchingisaresultofbothphysicalandchemicalprocesses.Phase1hatchingexposeslayerJ1tothemediumwhich,incontrasttojellylayersJ2andJ3ispartiallysoluble,andpermitsitsgradualdissolutionduringPhase2.Theembryosecretesaproteolyticenzymefromthefrontalregionwhichpartiallydigeststhefertilizationenvelope;subsequentembryomovementrupturestheweakenedenvelopeandcompletesthehatchingprocess.
[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]
