Opsins and Extraocular Photoreception
Berghia and Melibe respond behaviorally to illumination of posterior epidermis with white or red light
Animals responded with head-waving behavior when the posterior dermis of the skin was illuminated with white or red light, via a focused fiber optic light. This response was significantly higher than baseline responses to infrared light and no light.
Animals responded with a significantly longer delay to red light stimulation, than white light.
Berghia responded at a higher rate to light-on stimuli, than to light-off, whereas Melibe responded at a higher rate to light-off.
This work was done by Caitlyn McGhee and is being followed up, with headless (eyeless) animals, by Molly Gingras.
Opsin protein is located in a variety of epidermal locations
Fluorescent in situ hybridization with custom RNA probes demonstrated that opsins were located in cerata (A), oral tentacles (B), rhinophores (C), and skin (D).
Multiple opsins were colocalized in the same cells. C = canonical opsin, NC1 = non-canonical opsin 1, and NC2 = non-canonical opsin 2.
This work was done by Shykalia Nelson and other opsin localization has been done by Molly Gingras.