Fig. 2. Colocalization analysis of Mgn expression with GABAergic markers in the developing mesencephalon. (A-H) Expression of Mgn (C,D) and Gad67 (E,F) in adjacent coronal (A,C,E,G) and sagittal (B,D,F,H) sections of E12.5 mouse embryos. (A,B) Bright-field images. (G,H) Superimposed images of the two adjacent sections hybridized in parallel with Mgn (in yellow) and Gad67 (in blue) indicate that Mgn and Gad67 are expressed in close vicinity but do not colocalize. At E12.5, Mgn is expressed in the ventricular zone underlying the mantle layer in which Gad65/67 expression arises. However, no overlapping of the two expression domains can be observed. This spatial relationship between the two expression domains is especially intriguing in the developing mesencephalon (G), but also detectable in other expression domains such as the ZLi (H). SC, superior colliculus; IC, inferior colliculus; vMb, ventral midbrain.