Transcriptome profiling reveals BMP target genes during midbrain neural crest delamination

BMP signaling plays iterative roles during vertebrate neural crest development from induction through craniofacial morphogenesis, having been implicated in events from induction to survival and differentiation. However, far less is known about the role of BMP activity in cranial neural crest epithelial-to-mesenchymal transition and delamination. By measuring canonical BMP signaling activity as a function of time from specification through early migration of avian midbrain neural crest cells, we find elevated BMP signaling during delamination stages. Moreover, inhibition of canonical BMP activity via a dominant negative mutant Type I BMP receptor show that BMP signaling is required for delamination from the midbrain. Transcriptome profiling on control compared to BMP-inhibited cranial neural crest cells identified novel BMP targets during neural crest delamination including Notch pathway genes that are upregulated following BMP inhibition. These results suggest potential crosstalk between the BMP and Notch pathways in the early migrating cranial neural crest and provide novel insight into mechanisms regulated by BMP signaling during early craniofacial development.