Fig. 4. Zic2 and EphB1 are not expressed in VT retina in Foxd1 (BF-2 in figure) deficient embryos. (A,B) Cryosections of E16.5 Foxd1^+/+ (A) and Foxd1^lacZ/lacZ (B) embryos showing similar Islet1/2 expression in both wild type and mutants. (C-F) Zic2, detected by anti-Zic2 antibodies, in frontal sections from wild-type and Foxd1^lacZ/lacZ embryos. (C,D) At E14.5, Zic2 is not detected in Foxd1^lacZ/lacZ VT retina (elongated arrows, D; compare wild type in C), but it is detected in the ciliary margin zone (short arrows). (E,F) At E16.5, Zic2 expression seen in wild-type VT retina (E) is absent in the mutant (F). (G,H) In situ hybridization for EphB1 in frontal cryosections of E15.5 Foxd1^+/+ (G) and Foxd1^lacZ/lacZ (H) embryos reveals that EphB1, like Zic2, is absent in embryos lacking Foxd1. (I,J) mRNA for Islet2 is similarly expressed Foxd1^lacZ/lacZ and Foxd1^+/+ retina. Scale bars: 100 µm.