Meeting Abstract
P1.156 Friday, Jan. 4 Proteomic changes in gill tissue during acute aerial heat stress in tidally entrained Mytilus californianus HERNANDEZ, D*; SCHUMAN, M; TOMANEK, L; Cal Poly, San Luis Obispo dherna07@calpoly.edu
The rocky intertidal mussel species Mytilus californianus is native to the Pacific coast of North America. It is frequently exposed to temperatures that can induce the cellular stress response due to the tidal rhythm. Mussels were collected just prior to the experiment in a location with recorded thermal history and immediately placed in an artificial tidal cycle so as not to interrupt the entrainment. These mussels were selected to test the hypothesis that oxidative stress is a co-stressor of acute heat stress and triggers the production of a number of metabolic proteins to deal with the production of reactive oxygen species under naturally occurring conditions of aerial exposure. Immediately before the second artificial low low tide, mild (25 °C) and severe (35 °C) heat stresses were induced by increasing the air temperature at a rate of 6 °C per hour. Once reached, the target temperatures were held for one hour while a control group was left at 10 °C under aerial conditions. Gill tissues were sampled from individuals immediately after heat stress or placed back in the tidal cycle and sampled immediately prior to the next low low tide. Tissues from all individuals were prepared for analysis using 2D gel electrophoresis and subsequent 2D gel image analysis (two-way ANOVA; p<0.02). 21% of the proteins showed time-dependent heat stress (interaction) effect; 32 and 17% showed a heat stress or time (main) effect, respectively. A partial suite of the significant proteins have been identified using matrix-assisted laser desorption ionization (MALDI) tandem time-of-flight (ToF-ToF) mass spectrometry. Present data suggests that tidally-entrained M. californianus may be acclimatized to the possible occurrence of cellular damage through heat shock because of adjustments to hypoxia episodes that accompany low low tide episodes and also generate reactive oxygen species.
