Figure 1. Quail-chick chimeras reveal the axial level of origin of ENCCs.
Vagal-level neural tube, adjacent to somites 1–7, is removed from a quail embryo and grafted into the equivalent position in a stage-matched chick following removal of the host vagal neural tube (A). Vagal-derived ENCCs are subsequently found along the length of the intestine, as schematically depicted (C, stars). When a similar chimera is made using the sacral neural tube posterior to somite 28 (B), sacral-derived ENCCs are found in the post-umbilical gut, primarily in the colorectum and Nerve of Remak (C, black circles).