38.7 Sunday, Jan. 5 09:30 Visual opsins in non-visual photoreceptors: A common solution for extraocular light detection KINGSTON, A*; CRONIN, T; Univ. of Maryland, Baltimore County; Univ. of Maryland, Baltimore County firstname.lastname@example.org
Non-visual photoreceptors are common throughout the animal kingdom. Most previously described non-visual photoreceptors function using opsins that are not typically used for vision. However, recent work shows that conventional visual pigments exist and function in some non-visual photoreceptors, and we have discovered the presence of visual opsins in a number of non-visual photoreceptors. Crayfish (Procambarus clarkii) have a photoreceptor in the 6th abdominal ganglion that has been previously characterized both physiologically and behaviorally. We used molecular tools to identify a single opsin in the 6th abdominal ganglion that is likely to be associated with this photoreceptor. This opsin has the same predicted amino acid sequence as the long wavelength-sensitive opsin found in R1-7 cells in the retina. Furthermore, we have identified the same opsin in each individual ganglion of the nerve cord as well as in the brain, which suggests that the entire ventral nerve cord is light sensitive. In coleoid cephalopods, we have isolated visual opsins from the skin of several species. In the squid Doryteuthis pealeii, evidence suggests that the same opsin is coupled to a typical rhabdomeric-type visual phototransduction cascade in both the retina and skin. It now appears that the use of visual opsins for non-visual tasks is common, and that many animals employ the same visual pigments for both vision and for extraocular light detection.