The absence of cell death during development of free digits in amphibians☆
[摘要] Massivecellulardeathoccursintheinterdigitalregionsofdevelopinglimbsoffree-digitedbirdsandmammals.Thismesodermaldegenerationoccursatthesametimethatdigitsbecomefree.Thepresentstudyofdigitformationinamphibians,usingvitalstainingandhistologicalandautoradiographictechniques,demonstratestheabsenceofzonesofinterdigitaldegenerationduringtheformationoffreedigits.Furthermore,nootherareasofpredictablecelldeathoccurduringamphibianlimbdevelopment,asituationquiteunlikethecaseforavianlimbdevelopmentwherepredictablezonesofdegenerationoccurinthemesodermalongthepre-andpostaxialbordersofthedevelopingwingandleg.Thus,zonesofcelldeatharenotapartofamphibianlimbmorphogenesis.Analysisofthelabelingindexofthedevelopingfree-digitedforelimbofXenopuslaevisrevealsthatduringstage52theinterdigitalanddigitallabelingindexesarethesame.Thechangeintheratioofinterdigitallabelingindextothedigitallabelingindexintheforelimbsuggeststhatduringsubsequentdevelopmenttheinterdigitallabelingindexdecreaseswhilethedigitallabelingindexismaintained.Incomparison,thesameanalysisindicatesthattheinterdigitallabelingindexofthewebbedhindlimbincreaseswhencomparedtothedigitallabelingindex,whichstaysthesamefromearlytolatestages.ItisproposedthatfreedigitsdevelopinXenopuslaevisforelimbasaresultofadecreaseintheproliferationrateoftheinterdigitalregionascomparedtothedigitalregion,whichremainsunchanged.Conversely,webbeddigitsdevelopinthehindlimbasaresultofaninterdigitalrateatleastequaltothedigitalrate.
[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]
