The neural crest is a powerful regulator of pre-otic brain development

► The head skeleton is a “product” of the early neural primordium. ► Hox gene expression by the facial neural crest prevents head development. ► The removal of the Hox-negative neural crest depletes Fgf8 in brain organizers. ► The production of Fgf8 in the ANR, isthmus and BA1 ectoderm by the cephalic NC. ► Brain and face form a “developmental unit” under the control of the neural crest.