Meeting Abstract

P1.137  Sunday, Jan. 4  Detection and Localization of a Possible Photoreceptive Pigment in Temperate Holothurians (Echinodermata) PATTEN, S.B.*; NESTLER, J.R.; Walla Walla University, College Place, WA; Walla Walla University, College Place, WA steven.patten@wallawalla.edu

Many echinoderms have the ability to detect light, either by primitive eyes or through a diffuse dermal detection called extraocular photoreception. Johnsen (1997) showed that an asteroid and an ophiuroid possibly contain a rhodopsin-like protein that is likely used for photoreception. Many holothurians have been shown to be photosensitive, but the cellular mechanism and components used have not been described. The current study was designed to determine if photosensitive temperate holothurians have a rhodopsin-like protein that may be used for photoreception. Photopigment protein was detected by western blotting using two monoclonal antibodies raised against bovine rhodopsin (MW=39 kDa). Pharyngeal retractor muscle taken from Cucumaria miniata during both winter and summer show a solitary band at about 40 kDa. Tube feet (with skin) and respiratory tree from C. miniata in summer also show a solitary band at about 40 kDa. Oral tentacle and tube feet from Parastichopus californicus have also shown solitary banding at about 40 kDa. Continuing research is investigating two more species, Eupentacta quinquesemita and Psolus chitonoides and determining the effect of light on photopigment protein levels. The protein in question, which binds rhodopsin antibodies, is in the molecular weight range of rhodopsins, and is found in photosensitive holothurians, will be isolated and sequenced to determine if it is a photoreceptive pigment.