Fig. 5. Overexpression of dnPKA leads to proximodistal defects. Embryos were injected at the two-cell stage with RNA for dnPKA (B,D), then cultured until stage 39. (A,C) Control embryos. In situ hybridisation on cross-sections was then performed using Pax2 (A,B) or Pax6 (C,D) probes (dark blue). Overexpression of dnPKA leads Pax2 expression to expand in the neural retina compared with the control (arrowheads), whereas it inhibits expression of Pax6 in the ventral retina (arrowhead). le, lens. Dorsal is towards the top. Scale bar: 40 µm.