Morphology and proliferation during early feather development☆
[摘要] Thefirstbackfeathersofchickenembryosappearinregionswhereadensedermisispresent.Theearliestrecognizablestageoftheindividualfeatherinvolvesaclusterofelongatedepidermalcellswhichformslightlybeforeorcoincidentwithanearlydermalcondensation.Thymidine-H3incorporationandmitosisarevirtuallyabsentfromthecondensationsandoverlyingepidermisforaperiodofabout24hoursafterformation.DNAsynthesisandmitosiscommenceagaininbothtissuesasfeatheroutgrowthbegins.Quantitativestudiesofdermalcelldensity,andresultsoflabelingwiththymidine-H3,suggestthatthecondensationsariseasaresultofdifferentialmitoticactivitybeneaththeepidermalfeatherplacodes.Cellsinthecondensationssubsequentlyremainnearthetipofthedermalcore,whilecellsoriginallyattheedgeofthecondensation,orinthesurroundingdermis,makeamajorcontributionofdaughtercellstothebasalandlateralpartsofthedermalcore.Recombinationexperimentsindicatethatbothdermisandepidermisofskinseparatedatthenonproliferativephaseoffeatherdevelopmenthavethecapacitytoformfeathersinvitrowhencombinedwithmoreprimitivebacktissues.Theseandotherobservationsarediscussedinrelationtotheconceptofinductioninthefeather.
[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]
