Visual Transduction in the Sea Anemone Nematostella vectensis
The sea anemone Nematostella vectensis, within the phylum Cnidaria (jellyfish, anemones, corals), has a complex and understudied visual system, and is able to regenerate its visual cells, a function absent in humans. Its visual cells express opsins, proteins present in most animals, that sense light and convert it into a cellular signal. N. vectensis has 29 opsins compared to only 4 in human rods and cones. Studying the characteristics of opsin-expressing cells in sea anemones could provide insights into the evolution of visual systems and how visual cell development compares to regeneration. In order to understand the function of opsins and the process of visual transduction in N. vectensis, opsin-expressing cells were labeled with a fluorescent reporter and imaged with confocal microscopy. This was done as a part of a larger analysis into the function of these opsins in the visual pathway during development and regeneration. I imaged transgenic larvae, which revealed the localization of opsins to possible sensory cells on the surface of the animal. To predict the specific genes involved in visual signal transduction within these opsin-expressing cells, I used bioinformatic techniques and identified 22 genes in 14 maximum likelihood trees. In addition, I identified a possible Cnidaria-specific G protein alpha group involved in the visual pathway. Further investigations could explore the expression of opsins during N. vectensis regeneration, as well as identify the role of the newly-discovered G protein alpha in opsin-expressing cells.