Supernumerary limbs of urodele larvae resulting from localized ultraviolet light☆
[摘要] LocalizedultravioletirradiationoftheelbowregionoftheforelimboflarvalAmbystomaresultsintwomajorchanges:extensiveregressionofthedistalendoftheupperarmandoftheproximalendoftheforearm;theestablishmentofasupernumerarylimbatthelevelofirradiation.Asasupernumeraryblastemaisestablisheditbearsacloseresemblance,exceptforitsposition,totheblastemaformedafterlimbamputation.Itisalocalaggregationofcellscoveredoverbyathickenedplateofepidermis,devoidofabasementmembrane.Theearliestblastematastudiedpossessnervefiberswhichextendintotheepidermalplate.Fullyformedsupernumerarylimbsvarygreatlyintheirmorphologicalcharacteristics.Thenumberofdigitsrangesfromonetosix.Withineachsupernumeraryarewell-developedskeletalelements,whichbeararesemblanceto,butarenotidenticalwith,thoseofanormalforearm,wrist,andhand.Fullyformedsupernumerarylimbsareordinarilywellinnervatedthroughtheestablishmentofbothflexorandextensornervetrunksasprominentbranchesofmaintrunkswithintheparentlimb.Extensiveanastomosesofnervetrunkshavebeenobservedatthebasesofsupernumerarylimbsintheareawhereregressionwasmostextensive.
[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]
