Meeting Abstract
Lumbriculus variegatus, an aquatic annelid, is capable of regeneration from a few body segments (Martinez and Zoran, 2009). In this study, we investigate photoreception during regeneration. Photoreceptors are found within the posterior-most segments of an adult worm, as suggested by Drewes and Fourtner (1989). A simple phototactic assay demonstrates a suite of behavioral responses when regenerating worm fragments are exposed to white light. Anterior (Ant) and posterior (Post) worm fragments demonstrate significant differences in the amount of time to negatively phototact [Control (C) vs Ant p= 0.42, df=5: C vs Post p=0.047, df=5]. Worms were also tested using an environmental chamber that provides a native habitat filled with sediment layers. To better describe location of photosensitive cells in posterior segments, Anti-Futsch (22c10; Developmental Hybridoma Bank) and Anti-G-α Subunit q/11/14 (Santa Cruz Biotechnology) antibodies, previously described as markers for photoreceptors in other worm species, were used. 22c10 immunoreactivity was localized to the cytoplasm within cells found along the ventral epithelial surface of the worm. These 22c10 positive cells are found adjacent to serotonergic axonal connections that extend toward the ventral nerve cord. G-alpha protein was more broadly expressed within small epithelial cells extending into the cuticle as well as within neuronal cell bodies extending from the ventral nerve cord. Taken together these data represent one of the most extensive studies of photoreception in Lumbriculus.
