Embryonic tissues as elasticoviscous liquids: II. Direct evidence for cell slippage in centrifuged aggregates
[摘要] Certainembryoniccellaggregatesdisplaybothsolid-likeandliquid-likepropertiesinorganculture.Whencentrifugedagainstsolidsubstrata,theseaggregatesundergosuddeninitialdeformationsfollowedbymoregradualshapechanges.Thus,theyareeithercompoundviscoelasticsolids(inwhichcellsfirststretchrapidly,thenslowly)orelasticoviscousliquids(inwhichcellsfirstquicklystretch,butthengraduallyslidebyoneanother).Todistinguishbetweenthesealternatives,wehaveexaminedcellshapesincentrifugallydeformedchickliveraggregates.Lightandelectronmicrographsshowthatinitiallystretchedcellswithinflatteningaggregatesgraduallyreassumetheiroriginalundisturbedshapesduringprolongedcentrifugation.Therefore,althoughthecellsthemselvesmayreacttostretchingforceslikeelasticsolids,theyslowlyslippastoneanotherwithinaggregatestorelaxstretchingforces,endowingtheaggregateswithliquidproperties.Slowcellslippagecanaccountnotonlyfortemporaryelasticsolidityandviscousliquidflowincellaggregates,butalsoforstress-freechangesinthepositionsandconfigurationsoftissuesmigratingwithindevelopingembryos.Regulationofcellslippagepropertiesmayshiftthemorphogeneticdependenceofembryonictissuesinsuccessivedevelopmentalstagesfromintracellulartointercellularforce-generatingmechanisms,orviceversa.
[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]
