In normal developed zebrafish, retinoic acid is abundant in abdominal part of the retina, where the development of cones and rods is obvious. This means retinoic acid is effective in cone and rod development and eye development. 正常发育的斑马鱼,腹部视网膜的RA丰富,视杆和视锥细胞的分化强烈,表明RA信号系统在视杆、视锥的分化成熟中和眼球早期发育起作用。