Scanning electron microscopy of chick epiblast expansion on the vitelline membrane: Cell-substrate interactions☆
[摘要] Cell-substrateinteractionshavebeenstudiedbyexaminingmigratingedgecellsoftheexpandingchickextraembryonicepiblastontheirnormalsubstrateandinculture.Scanningelectronmicroscopyshowsthattheouterfaceofthevitellinemembraneisarandommeshworkoffibrils(80nmdiam).Theinnerface,whichisthenormalsubstrateofepiblastexpansion,iscomposedofarandombranchedsystemoffibers(400nmdiam)overlainbyanetworkoffibrils(40nmdiam).Theepiblastedgeinsituhasradiallyorientedfilopodia(20μmlong,200nmdiam.),frequentlyextendingfrombroadlamellipodia.Blastodermsculturedontheinnerfaceofunincubatedvitellinemembraneexpandatanormalratebutdisplayrufflesaswellasfilopodiaandlamellipodia.Whentheblastodermisculturedontheoutermembranefacethereisnoexpansion,butcellsleavetheedgeandmigrateacrossthemembrane.Inthesecultures,rufflesareobservedontheventralepiblastface.Absenceofthemassofyolkincultureappearstopermitorprovoketheobservedruffling.Comparisonofdissociatedepiblastedgecellsandskinepithelialcells,culturedonglassandonthevitellinemembraneinnerface,indicatesthatepiblastcellsremainflattenedanddisplaycharacteristicfilopodiaonbothsubstrates,whereasskincellsdisplayrufflesonthevitellinemembranebutareflattenedonglass.Themodeofmigrationofepiblastedgecellsseemstobemoredependentonintrinsicfactorsthanthatofskincells.
[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]
