Cyp1b1 differentially regulated vsx2, shh, and pax6. Whole-mount in situ hybridization at 24 hpf demonstrated that vsx2 expression in the eye decreased in response to cyp1b1 overexpression (D, D') compared with Cyp1b1 MO knockdown (C, C'), control-injected (B, B'), and uninjected (A, A'') embryos. Note the appearance of tissue bridging the two optic cups in the cyp1b1 mRNA-injected embryo, as demarcated by vsx2 (arrow). Shha at 24 hpf showed increased expression in the midline floor plate between the eyes in embryos injected with cyp1b1 mRNA (arrowheads, H, H') compared with Cyp1b1 MO knockdown (G, G'), control -injected (F, F'), and uninjected (E, D') embryos. Pax6a and pax6b expression in the retina at 48 hpf decreased in response to cypb1 overexpression (L, L') compared with Cyp1b1 knockdown (K, K'), control-injected (J, J'), and uninjected (I, I') embryos.