Lessons from KO mice of the genes regulating retinal photoreceptor development and function

Retinal photoreceptor cells, composed of rod and cone photoreceptor cells, work as light detectors through phototransduction. Both rod and cone photoreceptor cells develop cell type-specific unique structures, including ribbon synapses and photosensitive outer segments. These elaborate structures are essential for proper photoreception, phototransduction, and signal transmission to secondary neurons in the retina. Degeneration of photoreceptor cells in human is characteristic in several inherited retinal diseases such as retinitis pigmentosa, macular degeneration, and Usher syndrome. Understanding of molecular mechanisms underlying photoreceptor cell development and maintenance is important for developing treatment for retinal degeneration diseases. We have been investigating molecular mechanisms of photoreceptor cell differentiation, maturation, function, and survival by mainly using mouse molecular genetics. Based on these studies, we are currently attempting to develop a novel neuroprotection method using mouse photoreceptor degeneration models. We will present our recent findings on function and possible neuroprotection of photoreceptor cells.