Fig. 4. Reciprocal cyclin D expression changes in cD1^-/- or cD2^-/- mice at E14.5. (A-D) The distribution of nuclei expressing cD1 or cD2 proteins is distinct and non-overlapping in the medial ganglionic eminence (MGE) at E14.5. Compared with WT (A,B), mice lacking cD2 (C) have as many cD1-immunoreactive cells in the VZ as WT MGE, but the SVZ has a few more cD1+ cells, partially compensating for loss of cD2. In mice lacking cD1 (D), cD2-immunoreactive nuclei are more prevalent in the VZ and are also observed in the deep SVZ to an extent similar to that in WT. (E-G) Compared with WT (E), Nkx2.1 expression in the E14.5 MGE is reduced in area in cD2-null mice (F), and the same or increased in cD1-null mice (G) (MGE perimeter bordered with dashed line). The asterisk denotes Nkx2.1 labeling in the mantle region that was present in all genotypes but more easily captured here owing to reduced MGE volume. (H-J) Compared with WT (H), Mash1 expression in the MGE is reduced in cD2-null SVZ (I) and enhanced in cD1-null SVZ (J) (dashed line demarcates the VZ/SVZ border).