Bmp5 Regulates Neural Crest Cell Survival and Proliferation via Two Different Signaling Pathways.

Neural crest progenitor cells, which give rise to many ectodermal and mesodermal derivatives, must maintain a delicate balance of apoptosis and proliferation for their final tissue contributions. Here we show that zebrafish bmp5 is expressed in neural crest progenitor cells and that it activates the Smad and Erk signaling pathways to regulate cell survival and proliferation, respectively. Loss-of-function analysis showed that Bmp5 was required for cell survival and this response is mediated by the Smad-Msxb signaling cascade.