Meeting Abstract

P1.107  Monday, Jan. 4  Hyposalinity causes changes in gill protein expression in the ribbed salt marsh mussel Geukensia demissa CLAUSEN, R.C.*; FIELDS, P.A.; Franklin and Marshall College; Franklin and Marshall College rudy.clausen@gmail.com

Geukensia demissa, the ribbed salt marsh mussel, is found along the east coast of North America from the Gulf of St. Lawrence to Northern Florida. In its intertidal habitat G. demissa is exposed to extreme changes in temperature, salinity, and hypoxia. Organisms exposed to environmental stresses, such as changes in salinity, may alter protein expression to maintain tissue function. To determine how protein expression changes in G. demissa in response to salinity, we acclimated mussels to 100% (35‰) artificial sea water (ASW), then exposed six individuals to 80%, 70%, 60%, or 40% ASW for 6 h, and allowed them to recover for 24 h in 100% ASW. Six control (100% ASW) individuals also were sacrificed after acclimation. Proteins extracted from gill tissue were detected by 2D gel electrophoresis. Thirty gels (6 replicates x 5 treatments) were analyzed using Delta2D gel image analysis software (Decodon). Using ANOVA, hierarchical clustering, and principle components analysis, we found little change in expression, compared to control, after exposure to 80%, 70% or 60% ASW. Exposure to 40% ASW, however, resulted in significant changes in protein expression (161 proteins up-regulated; 83 down-regulated out of 1178 detected protein spots). These results indicate G. demissa is able to withstand moderate reductions in salinity without large-scale changes in protein expression. More severe salinity change (40% ASW) leads to significant alteration in protein expression patterns. We will use tandem mass spectrometry to identify those proteins that change most significantly in expression after exposure to hyposalinity.