Meeting Abstract

P2.113  Jan. 5  Analysis of heat-shock and oxidative stress protein synthesis with 2D gel-electrophoresis in marine snails of the genus Tegula CAHILL, C. S.*; TOMANEK, L.; California Polytechnic State Univ., San Luis Obispo cscahill@calpoly.edu

The closely related congeneric species Tegula funebralis and T. brunnea occupy distinct vertical ranges along the physical gradient of rocky shores. T. funebralis inhabits the mid-intertidal (from +1.5 to -0.5 m below mean low low water) and is frequently exposed to air. T. brunnea inhabits the subtidal (-0.5 to -7 m below mean low low water.) and is rarely exposed to air. Variation in the heat shock responses of these two species have been shown to limit their vertical distribution ranges. However, other physical factors that cause osmotic, oxidative and hypoxic stress may also contribute to the difference seen in distribution between the two species. For example, respiration under immersed and emersed conditions may activate different levels of oxidative stress; expressed as a change in production of reactive oxygen species (ROS). Thus, adaptations to oxidative stress in T. funebralis but not T. brunnea may also determine the vertical distribution ranges of both species. We have used gill tissue of the intertidal T. funebralis to separate stress-induced proteins by isoelectric focusing and gel electrophoresis (two-dimensional gel electrophoresis) over a range of incubation temperatures and various levels of oxidative stress (activated by hydrogen peroxide). Currently we are analyzing the stress-induced protein expression profiles that we obtained. Subsequently, we will excise differentially expressed proteins, digest them with trypsin and prepare them for analysis with mass spectrometry. With peptide mass fingerprinting and the de novo sequencing of precursor peptides, by analyzing protein digests with a MALDI-TOF-TOF mass spectrometer, we are currently identifying a subset of the stress proteins.