Some vNCCs migrate along the mesentery during early developmental stages. (A) Top panel: Whole-mount images of Wnt1Cre;R26tdTom embryos with PHOX2B and TUJ1 staining showing the migration of vNCCs from E9.0 to E10.5. Note that PHOX2B is expressed in vNCCs and sympathetic neurons, but not in trunk NCCs or sacral NCCs. Middle panel: Magnified views of the corresponding regions from the top panels with TUJ1 staining. Bottom panel: Same regions as in the middle panel with TOM and PHOX2B staining. Based on TUJ1 signal, the presumptive margins of the gut are indicated by dotted lines. Arrowheads indicate vNCCs within the mesentery, and arrows indicate pioneer vagus axons. (B) Whole-mount image of an E11.5 gut. The dotted line marks the site of the transverse section in panel C. (B’) Magnified view of the boxed area in panel B. (B’’) Whole-mount image of an E11.5 gut, in which the gut mesentery and the stomach are separated. Note the presence of NCCs and NCC-derived neurons (TUJ1+) within the gut mesentery. (C) Transverse section through the midgut and hindgut. Arrowheads indicate mNCCs within the gut mesentery. White dotted lines mark presumptive margins of the midgut and hindgut. Red dotted line marks the mesenteric artery. HG, hindgut; MA, mesenteric artery; ME, mesentery; MG, midgut; ST, stomach.