Supernumerary limb structures after juxtaposing dorsal and ventral chick wing bud cells☆

摘要

Theformationofduplicatedwingskeletalelementsand/orextrawingmuscleswasstudiedbyjuxtaposingnormallynonadjacentembryonicchickwingbudcells.Awedgeofrightorleftstage21wingbudectodermandmesodermwasinsertedinaslitmadeinahoststage20to22rightwingbudatthesameanteroposteriorpositionasitspositionoforigin.Thedistaledgeofthedonorwedgeandhostwingbudwerealignedwitheachother.Donortissuewasgraftedintoahostwingbudinoneofthefollowingfouraxialrelationships:boththeanteroposterioranddorsoventralaxescorrespondedwitheachother(aadd);onlytheanteroposterioraxeswereopposed(apdd);onlythedorsoventralaxeswereopposed(aadv);boththeanteroposterioranddorsoventralaxeswereopposed(apdv).Ofthe63wingsresultingfromthecontrolaaddoperationandthe45wingsfromtheapddoperation,only12wingshadaduplicatedskeletalelement;ofthe69wingssectionedfromthesetwogroupsofoperations,onlyonehadanextramuscle.However,ofthewingsresultingfromtheaadvandapdvoperations(48and52cases,respectively),23hadaduplicatedskeletalelement;ofthe54wingssectionedfromtheseoperations,43wingshadonetofourextramuscles.Furthermore,whentheaadvoperationwasperformedwithawedgeofdonorquailwingbudectodermandmesodermormesodermalone,supernumerarymusclesformedinthesechimericwingsandtheyweremadeupofdonorquailandhostchickcellsoronlydonorquailcells.