New perspectives on pharyngeal dorsoventral patterning in development and evolution of the vertebrate jaw

摘要

Patterningofthevertebratefacialskeletoninvolvestheprogressivepartitioningofneural-crest-derivedskeletalprecursorsintodistinctsubpopulationsalongtheanteroposterior(AP)anddorsoventral(DV)axes.Recentevidencesuggeststhatcomplexinteractionsbetweenmultiplesignalingpathways,inparticularEndothelin-1(Edn1),BoneMorphogeneticProtein(BMP),andJaggedndash;Notch,areneededtopatternskeletalprecursorsalongtheDVaxis.Ratherthandirectlydeterminingthemorphologyofindividualskeletalelements,thesesignalsappeartoactthroughseveralfamiliesoftranscriptionfactors,includingDlx,Msx,andHand,toestablishdynamiczonesofskeletaldifferentiation.Provocatively,thispatterningmechanismislargelyconservedfrommouseandzebrafishtothejawlessvertebrate,lamprey.Thisimpliesthatthediversificationofthevertebratefacialskeleton,includingtheevolutionofthejaw,wasdrivenlargelybymodificationsdownstreamofaconversedpharyngealDVpatterningprogram./p/div