Meeting Abstract

P3.122  Sunday, Jan. 6  Mucosal C-type lectins in the eastern oyster Crassostrea virginica: Potential involvement in particle capture and mucosal immunity PALES ESPINOSA, E; JING, X; PERRIGAULT , M; ALLAM, B*; Stony Brook University, Stony Brook, NY Bassem.Allam@stonybrook.edu

Lectins are known to participate in the defense function of invertebrates where they play an important role in the recognition of foreign particles. They also contribute to other processes requiring carbohydrate-protein interactions such as symbiosis and fertilization. Our recent work has demonstrated the presence of lectins in the mucus covering bivalve pallial organs (gills, mantle, etc.) and showed the participation of these molecules in food particle sorting in suspension-feeding bivalves. Here we describe a novel mucosal lectin from the oyster Crassostrea virginica (CvML) and present evidence for its involvement in oyster physiology. The sequence of this lectin presents a signal peptide, a single carbohydrate recognition domain, and two putative conserved sites for calcium binding indicating some levels of homology with previously described C-type lectins in molluscs. CvML transcripts were specifically expressed in mucocytes lining the epithelium of the digestive gland and the pallial organs but were not detected in other tissues including hemocytes. Further investigations demonstrated that the expression of CvML was significantly up-regulated following starvation or bacterial bath exposure but not after injection of bacteria into oyster’s adductor muscle. These results highlight the potential role of CvML in the interactions between suspension-feeding bivalves and waterborne microorganisms at the pallial interfaces with possible involvement in primary physiological functions such as food particle capture or mucosal immunity. Findings are discussed in light of our latest findings on the repertoire of mucosal lectins in marine mollusks.