Figure 6.

mNCCs migrate into the gut to contribute to the ENS. (A) Temporal tracing of NCCs in Plp1^CreERT2;R26^tdTom embryos from E7.5 to E9.5. The dotted line marks the site of section on the right. Arrowheads indicate TOM⁺/SOX10^- premigratory NCCs within the neural tube (NT). Green arrows and red arrows indicate TOM^-/SOX10⁺ and TOM⁺/SOX10⁺ migratory NCCs, respectively. (B and C) Immunofluorescent detection of SOX10 and TOM in the midguts of E14.5 Plp1^CreERT2;R26^tdTom embryos after corn oil (CO) and TM injection at E9.5. Corn oil–induced control midgut showed much lower basal CreERT leakage, thus CreERT leakage does not hamper lineage tracing of NCCs. (D) Representative midgut from E14.5 Plp1^CreERT2;R26^tdTom embryos with SOX10 staining. Temporally traced mNCCs seem to be undergoing mesentery–gut migration. (E) Quantification of the proportion of TOM⁺/SOX10⁺ cells relative to the total number of SOX10⁺ cells. Note the higher tracing efficiency of mNCCs in embryos with 12-hour tracing from E14.0 (n indicates the number of samples). (F) Representative midgut segment from E14.5 Plp1^CreERT2;R26^tdTom;Chat^GFP embryos with 12 hours of tracing. Traced mNCCs invade the gut and differentiate into cholinergic (TOM⁺/GFP⁺/SOX10^-; white arrowheads) and noncholinergic (TOM⁺/GFP^-/SOX10^-; red arrowheads) neurons. Arrows indicate NCCs or NCC-derived glia (TOM⁺/GFP^-/SOX10⁺). (G) Quantification of the percentage of traced mNCCs within the gut (n = 875 NCCs within the midgut from 5 embryos). ME, mesentery; NT, neural tube.