Fig. 5. Rx3 is not required for retina determination. Dorsal views of two-somite stage (A-F) and six-somite stage el-mutant embryos (G,H). Anterior is towards the left. (A,E,G) Mouse Six3 RNA injected, (C) medaka Six3 RNA injected, (B,D,F,H) control injected el-mutant embryos raised at restrictive temperature. (A,B) Six3 overexpression does not result in Rx3 expression in el-mutant embryos. (B,C) Ectopic Pax6 expression (arrowhead) in the midbrain in response to Six3 overexpression. (E) Six3 overexpression results in ectopic Six3 expression in the presumptive midbrain (arrowhead) (G) Overexpression of Six3 results in expanded and ectopic Rx2 expression (arrowhead) in forebrain and presumptive midbrain, respectively. Abbreviations: fb, forebrain; hb, hindbrain; mb, midbrain.
