Meeting Abstract

P1.97  Jan. 4  Two-dimensional gel electrophoresis analysis of protein expression in two populations of the arrow goby Clevelandia ios JOHNSON, S.E.; SEGAL, M.A.*; TOMANEK, L.; California Polytechnic State University; California Polytechnic State University msegal@calpoly.edu

Clevelandia ios, also known as the arrow goby or commensal goby, is commonly found in the estuaries of Morro Bay in central California. This small vertebrate exhibits a commensal relationship with the fat innkeeper worm, Urechis caupo. The goby enjoys the shelter of the burrow and discarded food particles provided by the worm. As it is stationary, it is a useful indicator of spatial heterogeneity of anthropogenic inputs of nutrients, e.g. nitrates. Samples from two populations of arrow gobies have been collected from two sites in Morro Bay, in the Marina and Santa Ysabel. Based on preliminary water quality surveys, the two sites differ in nutrient concentrations, with Santa Ysabel being the more nutrient rich site. Changes in nutrient levels, such as nitrates, may effect the expression of certain proteins. We chose to examine protein expression profiles from goby liver tissue by separating proteins, first, by isoelectric focusing and, second, by gel electrophoresis (two-dimensional gel electrophoresis). Liver tissue is easily extracted and has been used in similar experiments because of its relative sensitivity to environmental change. Using two-dimensional gel electrophoresis, we have been able to detect over 800 protein spots that differ in their isoelectric point (pI) and their molecular mass. We are currently analyzing these gel images to detect protein spots that are differentially expressed at the two sites. We are correlating expression profiles from field-acclimatized gobies to animals that were exposed to increased nitrate levels under laboratory conditions in order to identify the possible toxic effects of nitrate exposure under field conditions. Proteins thus identified will be subjected to further analysis by peptide mass fingerprinting and de novo sequencing, using MALDI-TOF-TOF mass spectrometry.