Loss of Shox2 function in the facial motor nucleus interferes with the proper development of the medial subnuclei. a Diagram of a coronal section through the P0 brain highlights the region represented in panels b–v, particularly the 7 neuronal clusters that form the facial motor nucleus (nVII, dashed-circle) (image adapted from [23]). b X-gal stained coronal sections through P0 brains shows a loss of medial neuronal clusters in the facial motor nucleus of Nestin-Cre; Shox2
lacZ/flox (B″) brains as compared to controls (B′). c–v ISH on P0 control (c, e, g, i, k, m, o, q, s, u) and Nestin-Cre; Shox2
flox/− (d, f, h, j, l, n, p, r, t, v) coronal sections shows loss of Shox2 expression (compare c to d, dashed-circle), and decreases in Isl1 (compare e to f, dashed-circle), Phox2b (compare g to h, dashed-circle), Cntn2 (compare i to j, dashed-circle), Tubb3 (compare k to l, dashed-circle), Periph (compare m to n, dashed-circle), Slc18a3 (compare o to p, dashed-circle), Slit2 (compare q to r, dashed-circle), Shh (compare s to t, dashed-circle) and Ptch1 (compare u to v, dashed-circle) expression in the facial motor nucleus. DA dorsal accessory, DM dorsomedial, VM ventromedial, DI dorsal intermediate, VI ventral intermediate, DL dorsolateral, Lat lateral. Scale bar 250 μm.