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.