Figure 2. Neuronal specification in Munc18-1−/− mice. At E11.5, Olig2 (A, B, E) and Nkx2.2 (C, D, F) progenitors are present in numbers similar to WT: Olig2: 47.49 ± 2.65 (+/+, n = 3), 49.16 ± 1.863 (−/−, n = 3, p = 0.64; Nkx2.2: 130.2 ± 2.48 (+/+, n = 2), 127.9 ± 1.57 (−/−, n = 2), p = 0.88. The number and distribution of Nkx6.1 (A, B) progenitors appears similar in both genotypes. The numbers and distributions of Chx10+ (G, H), En1+ (I, J), Evx+ (K, L), and Cav1.2+ (M, N) neurons also appear similar between genotypes at E12.5. In the lumbar spinal cord of E13.5 mice, numbers of Isl1+ (O, P, U; 46.65 ± 6.33, +/+, n = 4, 42.68 ± 6.07 (−/−, n = 5, p = 0.67), Lim1+ (Q, R, V; 27.59 ± 4.58, +/+, n = 4, 32.08 ± 6.44 (−/−, n = 3, p = 0.58), and Foxp1+ (S, T, W; 76.64 ± 7.37, +/+, n = 4, 87.66 ± 2.66 (−/−, n = 5, p = 0.17) motor neurons are similar between genotypes. Proportions of Isl1+ (X; 56.88 ± 1.59, +/+, n = 4, 49.03 ± 6.54, −/−, n = 5, p = 0.3) and Lim1+ (Y; 41.35 ± 3.56, +/+, n = 4, 42.26 ± 7.17 −/−, n = 3, p = 0.91) LMC motor neurons are also similar.