Fig. 1. Cellular expression of visual pigments and retinal mosaic expression in Atlantic halibut (Hippoglossus hippoglossus). The cellular identities of the different photoreceptors in the retina of Atlantic halibut larvae at the end of the yolk-sac period (40 days post-hatching) were investigated by in situ hybridisation analysis with RNA probes for the four different Atlantic halibut cone opsins: ultraviolet (A,B), blue (C,D), green (E,F) and red (G,H). A,C,E,G are radial sections, while B,D,F,H are tangential sections. Expression patterns in tangential sections from the central retina are with blue, green and red opsin probes, respectively, while tangential sections in the ventral retina are with ultraviolet opsin probe. Black arrows indicate photoreceptor cells expressing the respective opsins. The white arrow indicates photoreceptor cells that do not express green-sensitive opsin. ONL, outer nuclear layer; PE, pigment epithelium. Scale bars, 10µm.
