Importance of SoxE in neural crest development and the evolution of the pharynx

Neural crest cells are a defining character of vertebrates, patterning the face and much of the head and pharyngeal or gill region in the embryo. In the primitive jawless vertebrates known as lampreys, however, the pharynx is structurally very different from that of jawed vertebrates, raising questions about the role of the neural crest in patterning homologous structures. An experiment using targeted misexpression of SoxE genes, which pattern the head in jawed vertebrates, confirms that they fulfil similar functions in lampreys. So regardless of structural differences, the pharyngeal structures of all vertebrates do appear to be homologous.