Fig. 2. add mutation behaves in a cell-autonomous manner. (A) Transplantation of wild-type cells into wild-type retinas. Wild-type donor cells (green) are BrdU-negative and differentiate into retinal neurons, which form retinal columns. (B) Transplantation of add mutant cells into wild-type retinas. add donor mutant cells (green) fail to form retinal columns and continue to incorporate BrdU (red in broken white circle) in the wild-type recipient retina. (C) Transplantation of wild-type cells into wild-type retinas. Wild-type donor cells (green) differentiate into double cone-type of photoreceptors, which are labeled with zpr1 antibody (red). (D) Transplantation of wild-type cells into add mutant retinas. Wild-type donor cells (green) express the photoreceptor marker, zpr1 (red in white dotted circle) in the add-recipient retina.