P3.48 Friday, Jan. 6 Time Course of Protein Expression Changes in Response to Acute Heat Stress in the Mussel Geukensia demissa COX, Kelly M.*; FIELDS, Peter A.; Franklin and Marshall College; Franklin and Marshall College firstname.lastname@example.org
Little is known about the time course of change in protein expression following stress because proteomic changes are usually only examined at one recovery time point. In this experiment, I examine changes in protein expression in the ribbed mussel Geukensia demissa over time in response to acute heat stress. Geukensia demissa occurs in the intertidal zone of salt marshes from the Yucatan Peninsula to Maine, and can experience wide and rapid fluctuations in temperature. In this experiment, subjects obtained from a population in southern New Jersey were acclimated to 15° C for three weeks. Replicates of six mussels were heated to 40° C over a period of 40 minutes, held at temperature for one hour, then allowed to recover at 15° C for a period of 0, 3, 6, 12, 18 or 24 hours. Protein was extracted from gill tissue and separated by 2-D gel electrophoresis. Image analysis software was used to visualize the gels and to compare changes in spot density patterns between treatment groups. An ANOVA test was used to identify proteins whose abundance changed significantly after heat stress. Proteins found to have significantly different expression levels between treatment groups were excised and identified using liquid chromatography-tandem mass spectrometry (LC-MS) and bioinformatic (Mascot) analysis. Preliminary findings show that a stress response is detectable very early in the recovery period. Initial protein identifications suggest this rapid response addresses oxidative stress first (3 h), followed by an increase in chaperone proteins (12 h).