Fig. 7. Non-autonomous rescue of photoreceptors at 72 hpf by wild-type cells transplanted into shh mutant embryos. Wild-type cells are labeled with biotin (blue) and they also carry the shh-GFP transgene (green). Photoreceptors are detected with an antibody recognizing Zpr1 (red). (A) Photoreceptors are rescued when they are found in the region of the retina containing wild-type shh-expressing cells in the neural retina. The arrow indicates shh mutant cells that are rescued. (B) Higher magnification of the image shown in A. Arrowheads point to non-autonomously rescued cells. (C) Another example of the rescue of photoreceptors. (D) Higher magnification of the image shown in C. Arrowheads point to non-autonomously rescued cells. (E) A further example of rescue. Note that there is a gap in the rescued photoreceptors in exactly the same region as where there are no shh-expressing cells in the neural retina (arrow). (F) Example of failure to rescue photoreceptors when wild-type cells are located only in the RPE (arrowheads). (Inset) Enlarged view of framed area.