Dorsal and ventral cells of cleavage-stage Xenopus embryos show the same ability to induce notochord and somite formation☆

摘要

Cellsinthedorsalmarginalzoneoftheamphibianembryoacquirethepotentialformesodermformationduringthefirstfewhoursfollowingfertilization.Anexaminationofthoseearlycellinteractionsmaythereforeprovideinsightonthemechanismsimportantfororganizationofaxialstructures.Theformationofmesoderm(notochord,somites,andpronephros)wasstudiedbycombiningblastomeresfromtheanimalpoleregionofXenopusembryos(32-to512-cellstages)withblastomeresfromdifferentregionsofthevegetalhemisphere.Thefrequencyofnotochordandsomitedevelopmentwassimilarincombinationsmadewithdorsalorventralblastomeres,orwithboth.Ourresultsshowthatduringearlycleavagestagestheventralhalfofthevegetalhemispherehasthepotentialtoorganizeaxialstructures,apropertypreviouslybelievedtobelimitedtothedorsalregion.