Fig. 1. Eomes expression in the developing retina. Retinal sections from the indicated developmental stages were labeled with an Eomes antisense probe (A,B) or anti-Eomes antibody (C-K). Eomes expression starts at E14.5 in the innermost layer of developing retina (A). At E16.5, Eomes expression is mainly localized in the same area (B, black arrowhead) and in the forebrain (white arrowhead). At E13.5, although Eomes expression is detected in the developing forebrain (C, arrowhead), it is undetectable in the retina. (D,E) In Math5^+/- retinas (D), Eomes is detected in the GCL (strongly) and NBL (weakly), but in Math5^-/- retinas (E), Eomes expression in GCL is undetectable. (F-H) At E14.5, Pou4f2 and Eomes colocalize in RGCs in the innermost layer. Developing RGCs in the NBL with strong Pou4f2 expression are Eomes negative. Weak Eomes expression can be detected in the NBL at E14.5. (I-K) At E16.5, expression of Pou4f2 and Eomes is largely restricted to the GCL. Scale bars: 500 µm in C; 200 µm in D,E; in H, 100 µmfor F-H; in K, 50 µm for I-K.