Meeting Abstract
P3.203 Sunday, Jan. 6 Thermal Sensitivity of Heat Shock Protein Gene Expression in Newly Settled Porcelain Crabs TURNER, CR*; STILLMAN, JH; DORFMAN, RE; PAGE, TM; California State University, Monterey Bay; Romberg-Tiburon Center: San Francisco State University; Romberg-Tiburon Center: San Francisco State University; Romberg-Tiburon Center: San Francisco State University cturner@csumb.edu
Intertidal zone organisms are adapted to thermal extremes, and upper vertical zonation limits are known to be set by thermal tolerance limits. While much is known of thermal tolerance in adults, there are fewer studies that have examined the impact of heat waves on newly settled juveniles that were not exposed to thermal variation in their larval planktonic period. In order to examine the impact of heat waves among newly settled juvenile porcelain crabs, we determined the induction temperatures for heat shock protein (hsp) gene expression in two porcelain crab species that inhabit different intertidal zones: the less heat tolerant low intertidal Petrolisthes manimaculus and the more heat tolerant mid-upper intertidal Petrolisthes cinctipes. Due to the ecological differences between the species, we hypothesized that hsp gene expression will begin at lower temperatures for P. manimaculus than for P. cinctipes. To assess organismal response to heat stress, we performed quantitative real-time PCR using housekeeping gene α-Tubulin and target genes hsp40 and hsp90α, both of which were highly expressed in prior microarray studies of thermal stress responses in adult P. cinctipes. Hsp40 induction occurred between 23-25.5°C in both P. manimaculus and P. cinctipes. In contrast, hsp90α induction was between 21- 23°C in P. manimaculus, but 25.5°C in P. cinctipes. Our initial analyses suggest that interspecific differences in thermal stress tolerance may be in part due to differences in induction temperatures of hsp90 between species. Further work is needed to quantify whether we observe ontogenetic shifts in the hsp90 induction temperature in each species.
