Meeting Abstract

8.9  Sunday, Jan. 4  The role of glucosamine in mate recognition of the caridean shrimp Palaemonetes pugio CASKEY, J.L.*; WATSON, G.W.; BAUER, R.T.; University of Louisiana, Lafayette; University of Louisiana, Lafayette; University of Louisiana, Lafayette shrimpgirl@gmail.com

Chemical communication plays a major role in regulating many animal behaviors. It has been proposed that mating in crustaceans is highly dependent upon chemical cues that are a part of a highly adapted signal/receptor complex of a mate recognition system (MRS). Experimental evidence has shown that the MRS of Palaemonetes pugio involves a non-diffusible chemical signal produced by the female that elicits copulatory behavior from males upon contact. Two forms of carbohydrates utilized by crustaceans as chemical signals are oligosaccharide residues of glycoproteins and modified amino sugars hydrolyzed from proteoglycans. Several studies have demonstrated the importance of carbohydrate residues, particularly N-acetylglucosamine, in mate recognition in several species of harpacticoid copepods. The purpose of this experiment was to determine the role, if any, that glucosamine plays in mate recognition. A mating experiment showed that glucosamine significantly reduced the number of copulations (6 of 20) when compared to glucose (14 of 20). A 20 min time course series monitoring intracellular Ca²⁺ levels of male receptors showed an increase in Ca²⁺ levels when exposed to glucosamine (5 of 10) but not when exposed to glucose (0 of 10). When this same experiment was performed in Ca²⁺-free seawater, the same increase was seen, indicating that the intracellular Ca²⁺ appears to be an internal source. Based on these findings, male receptors appear to be lectin-like proteins capable of binding glucosamine, which inhibits mating. The binding of glucosamine to the receptors increases intracellular Ca²⁺ levels, which is hypothesized to be a second messenger molecule facilitating signal transduction.