Uncx4.1 expression in embryonic mouse midbrain compared with expression of neuronal subtype markers. (A-L) In situ hybridization analysis of Uncx4.1 (A, C, E, G, I, K), Nkx2.2 (B), Helt (D), Gad67 (F), Lmx1a (H), Ngn2 (J) and Nkx6.1 (L) expression on coronal sections of E11.5 or E12.5 wild-type mouse midbrain. (M, N) Immunohistochemistry (IHC) on E11.5 wild-type sections reveals that Uncx4.1 is co-expressed with Foxa2 (M) and tyrosine hydroxylase (TH) (N) in postmitotic neurons of the ventral midbrain. (N’) Higher magnification of the inlay in N. (O) IHC on E17.5 wild-type sections shows that at E17.5 most of the TH-positive cells have lost Uncx4.1 expression. (O’) Higher magnification of the inlay in O. (O”) Higher magnification of the inlay in O’ showing that Uncx4.1 is not expressed in TH-positive cells at E17.5. E, embryonic day.