Fig. 4. Restored gene expression in rescued mutant embryos. (A-F) Rx3 expression at the four-somite stage in mutant (A-C,E) and wild-type (D,F) embryos, dorsal views (A-D,F), injected with Rx3 plasmid (A,B), Rx3
HB plasmid (C,D) and controls (E,F); lateral view (E). Anterior is towards the left. (A,B) Optic vesicle evagination correlates with level of restored Rx3 expression (compare arrowheads in A,B). (C) Restored expression of nonfunctional Rx3 protein does not rescue. (A-D) Note specific Rx3 expression in mutant (A-C) and wild-type (D) embryos. Compare the homogenous wild-type Rx3 expression in control injected (F) and clonal expression in Rx3 plasmid injected mutant (A-C) and wild type (D) embryos. (E) Control injected mutant embryo lacks Rx3 expression. (G-L) Rx3 plasmid (G,J) and control injected (H,I,K,L) 12-somite mutant (G,I,J,L) and wild-type (H,K) embryos. Tbx2 and Tbx3 expression in the retina is rescued in Rx3 plasmid-injected embryos (compare arrowheads in G-I for Tbx2, and J-L for Tbx3). Note that expression of Tbx2 and Tbx3 in the hypothalamus (arrows in G-I and J-L, respectively) and Tbx2 expression in the otic vesicle (compare G-I) is not affected by the el mutation. (M-P) Transversal section of 22-somite (M,N) and 35-somite (O,P) uninjected wild-type (M,O) and Rx3 plasmid-injected mutant embryos (N,P). Dorsal is towards the top. (M,N) Vsx2 expression in wild-type (M) and rescued mutant embryo (N) in the ventral retina. (O,P) Vsx1 expression in inner nuclear layer of the wild type retina (O) is rescued in injected mutant embryo (P). Abbreviation: ov, otic vesicle.
