论文部分内容阅读
Bone Morphogenetic Proteins(Bmps)are believed to form a ventrodorsal activity gradient in vertebrate embryos and thereby control embryonic patterning although Bmp protein distribution in living organisms has not been established yet.However,transcripts of some Bmp genes are present in the organizer region of Xenopus and zebrafish embryos.The role of the organizer-specific Bmps in embryonic patterning remains elusive.We show that,in zebrafish gastrulas,Bmp2b protein forms a pattern along the ventrodorsal axis like the two-humped Bactrian camel.However,the downstream effectors p-Smad1/5/8 form a ventral to dorsal gradient due to inhibition of the organizer-specific Bmp2b by Chordin,a Bmp antagonist expressed in the organizer.