Spatiotemporal formation of the segmental ENS. mNCCs form segmental ENS within the aganglionic guts of (A) E14.5, (B) E16.5, (C) P0, (D) P4, (E) P12, and (F) P30 Wnt1Cre;R26tdTom;Ednrb-/- mice. (A) The green arrow indicates the migration wavefront of eNCCs that have stalled in the midgut. (A and B) Red arrows indicate pioneer pelvic ganglion-arising axons. (A’ and A’’) Higher magnification of the corresponding boxed areas in panel A showing solitary NCC clumps. (F’) Representative transverse section of the hindgut of a P30 Wnt1Cre;R26tdTom;Ednrb-/- mouse at the approximate site indicated by the dotted line in panel F, which shows that mNCCs differentiate into enteric neurons (TOM+/HU+) and glia (TOM+/GFAP+). (F’’) Magnified view of the boxed area in panel F’. CC, cecum; GFAP, glial fibrillary acidic protein; HU, type 1 anti-neuronal nuclear.