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Fig. 2.
Loss of Etv1 function prevents proneural gene expression. Etv1 function was blocked by injection of etv1 MO at the 8-cell stage (B,E,H,K,N,Q,T) or by transgenic expression of dnEtv1 using the eye-specific enhancer for human fzd5 (C,F,I,L,O,R,U). In situ hybridization on stage 28 embryos showed that expression of early retinal markers were unaffected relative to the uninjected side, including rax (A and B, n = 78/82 unaffected; C, n = 32/32), pax6 (D and E, n = 59/65; F, n = 15/15), sox2 (G and H, n = 51/58; I, n = 28/28), and the pre-neurogenesis bHLH gene ascl3 (J and K n = 37/37; L, n = 32/32). Expression of proneural bHLH genes required for retinal neurogenesis was reduced compared to the uninjected side: atoh7 (M and N, n = 70/124 reduced; O, n = 56/98), neurog2 (P and Q, n = 39/61; R, n = 20/34), and neurod1 (S and T, n = 53/103; U, n = 18/28). Arrows indicate the eye. |