Ventralization of an indirect developing hemichordate by NiCl2 suggests a conserved mechanism of dorso-ventral (D/V) patterning in Ambulacraria (hemichordates and echinoderms)

► Identification and characterization of novel tissue specific markers in P. flava. ► NiCl2 treatment disrupts dorso-ventral patterning outside the echinoderms. ► NiCl2 transforms dorsal ectoderm into ventral ectoderm. ► Conservation of a NiCl2 sensitive pathway in ambulacrarian D/V patterning.