Meeting Abstract

44.1  Jan. 6  Nitrate stress in the Morro Bay Ecosystem: Utilizing 2D gel electrophoresis to characterize protein expression profiles in Mytilus californianus TURNER, B. E.; TOMANEK, L.*; California Polytechnic State Univ., San Luis Obispo ltomanek@calpoly.edu

Estuaries depend on effluents containing complex mixtures of numerous anthropogenic and naturally derived chemical compounds, e.g. nitrogen. Increased nitrate and ammonia concentrations are known to adversely affect adult and juvenile marine invertebrates, including oysters and mussels. Thus we used the filter-feeding intertidal mussel Mytilus californianus as an indicator species to investigate the toxic effects of nitrogen. In this study, M. californianus were placed in one of three subtidal test sites experiencing various levels of effluent exposure in and around Morro Bay, an ecologically important Central Californian estuary. Two test sites are within Morro Bay, the first is closer to the mouth of the bay and benefits from tidal flushing, the second, in a sheltered portion of the bay that experiences less tidal flushing and is thus exposed to anthropogenic influences. A third site is located in Avila Bay, an open bay with relatively low nutrient levels and low effluent exposure. M. californianus was sampled from the three sites over a period of time. Significant rainfall events and changes in nutrient levels were monitored and animals were collected before and after these events. Protein expression profiles were characterized by isoelectric focusing and gel electrophoresis (two-dimensional gel electrophoresis � 2D GE). Gel images were analyzed and proteins showing significant differences in expression between test sites or before vs. after rain events are currently analyzed. Gill tissue from laboratory acclimated mussels was subjected to a gradient of nitrate concentrations in vitro. Proteins of interest from both studies will be identified using protein fingerprinting and de novo sequencing. These preliminary results are an example of using 2D GE to monitor estuarine environments for stress.