(full paper is archived in the Miller Library)
Title: Increasing length of exposure to cold stress casues decreased levels of heat shock portein expression in congeneric Tegula species
Student Author(s): Tyburczy, Will
Faculty Advisor(s): Somero, George
Location: Final Papers Biology 175H
Date: June 2003
Abstract: In this study I examined the endogenous levels of heat shock protein 70 (Hsp 72 and Hsp 74) in response to cold shock in the Tegula congeners T. funebralis, T. brunnea, and T. pulligo. Snails were exposed to seawater temperatures of either 10C or 40C (+0.50C) for either 2 or 10 hours, then placed back in ambient (130C) seawater. Levels of heat shock protein (Hsp) expression were quantified via western analysis after 2 and 10 hours of recovery in ambient temperature seawater. These levels were compared to control levels of Hsps recorded in snails not exposed to any cold treatment. In snails facing 10-hour exposure times, levels of Hsp 72 remained constant or decreased slightly relative to the control levels after 2 hours of recovery, while Hsp 72 levels after 10 hours of recovery were significantly lower than the control values. In contrast, levels of Hsp 72 expression in snails exposed for only 2 hours were not significantly different from control values after 10 hours of recovery. These data suggest that different exposures may confer different signals that activate distinct physiological responses to cold shock. If Hsps were detrimental to recovery from cold stress, longer exposures could result in down regulation in the levels of these proteins.