Uncx4.1 and Ngn2 are co-expressed in some immature neurons in WT embryos, whereas Uncx4.1 is missing in the ventral midline of Ngn2−/−embryos. (A-B) Analyzes of the expression of Uncx4.1 and Ngn2 using in situ hybridization ISH (A) and immunohistochemistry (IHC) (B) revealed that Uncx4.1 and neurogenin 2 (Ngn2) are co-expressed in some immature neurons of the ventral midbrain. It appears that on the mRNA level more double-positive cells are detected, as compared to IHC staining. (B’) display confocal microscopy higher magnification of the inlay in B. (C-F) IHC against Uncx4.1 and green fluorescent protein (GFP) on coronal sections of E11.5 (C-D) and E13.5 (E-F) embryos, showing that Uncx4.1 is depleted at the midline in the ventral midbrain of Ngn2−/− embryos as compared to WT. E, embryonic day; WT, wild-type.