Meeting Abstract

P2.118  Jan. 5  Analysis of heat-shock induced protein expression profiles in the Japanese oyster Crassostrea gigas HITT, L. R.*; TOMANEK, L.; California Polytechnic State Univ., San Luis Obispo lhitt@calpoly.edu

Japanese oysters, Crassostrea gigas, are grown and found along the Pacific coast of North America. Depending on the tidal height where they are grown or found, they can experience temperature variations of over 20�C during low-tide. In addition, their filter-feeding activity can lead to the accumulation of pollutants and other indicators of anthropogenic input, e.g. nitrates. We have obtained oysters from a farm in Morro Bay, located on Central Californian Coast. In order to investigate the heat-tolerance of oysters we exposed gill tissue to heat-shock inducing conditions (32�C and 37�C). We then separated proteins according to their isoelectric point (pI; isoelectric focusing) and molecular mass with two-dimensional gel electrophoresis. We detected over 700 different protein spots within the range of pH4-7, using large gel electrophoresis. Several spots were up- or down-regulated with an increase in temperature. We are currently analyzing these gel images further to identify the complete set of protein spots that are activated with heat-stress. We are also identifying proteins that are expressed with increasing levels of nitrates, which is a common anthropogenic input into estuaries where oysters are grown. Following excision of differentially expressed protein spots from gels and digestion with trypsin, proteins will be prepared for analysis with mass spectrometry. With the help of peptide mass fingerprinting and de novo sequencing of peptides, by applying MALDI-TOF-TOF (Time-of-flight) mass spectrometry, we will further analyze protein spots so they can be identified.