Temporal factors affecting localization of neural crest cells in the chicken embryo☆
[摘要] Totestthehypothesisthatpredeterminedcellsmigratefromthecrestinaspecificorder—thefirsttoleavelocalizingdistallyasentericpigmentcellsorsympatheticelements—tritiatedthymidine-labeledneuralcrestfromwhichmanycellshadalreadyemigratedwasgraftedintoanunlabeled,younghostenvironment.Radioautographsrevealedthatthecellswhichremainedinthecrestatthetimeofgraftingwerecapableofgivingrisetothefullrangeofdistalandproximalcrestderivatives.Thishypothesiswasthereforediscarded.Thealternatives(1)thatpredeterminedcellsleavethecrestinrandomorderandlocalizespecifically,or(2)thatpluripotentcellsrespondtochangesintheenvironmentthroughwhichtheymovecouldbedistinguishedwiththeconversesetofgraftingoperations.Whennewlycondensedneuralcrestwasgraftedintoprogressivelyolderhosts,distalmigrationoflabeledcellswasprogressivelyattenuated.Thissuggeststhat,atleastinpart,achangingembryonicenvironmentaffectstheextentofmigrationofneuralcrestcells.Itisproposedthattheultimateexpressionofadevelopmentaltraitbypluripotentcrestcellsmightberelatedsimplytothedegreeofdispersionofthesecellswithinotherembryonictissues,andthisinturn,isprobablyeffectedbytheextrinsiclimitationofcrestcellmigration,andspecificdevelopmentalalterationsincellularadhesiveproperties.
[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]
