In the vertebrate retina, there are two types of photoreceptors, rods and cones. Retinitis Pigmentosa is the most frequent cause of inherited retinal dystrophy characterized by progressive visual loss caused by degenerative abnormalities of rods. The goal of our lab is to understand the physiological functions of its causative genes in photoreceptors and the underlying molecular mechanisms causing Retinitis Pigmentosa. To this end, we have started to use zebrafish as an animal model. The fundamental structure of retina and photoreceptors and the process to perceive light are well conserved in both humans and zebrafish. Our basic approach is to create generically modified zebrafish, for example knockout or transgenic zebrafish, and analyse phenotypes using molecular biology immunohistochemistry, biochemistry and electrophysiology in vivo.