Meeting Abstract
P3.204 Sunday, Jan. 6 Localizing the cellular stress response in a simple body plan KINSEY, M.J.*; PLACE, S.P.; University of South Carolina, Marine Science; University of South Carolina, Biological Sciences and Environment and Sustainability Program kinsey@email.sc.edu
Intertidal organisms are often subjected to high levels cellular stress stemming from multiple abiotic factors such as desiccation and temperature extremes that can result in the activation of a nearly ubiquitous organismal response, known as the cellular stress response (CSR). Although highly important for survival during an extreme stress event, this response is also energetically costly. Therefore, the temporal and spatial nature of the response is likely an important factor determining the overall energetic costs. As such, integrating the molecular signals controlling the stress response across multiple tissues and body regions may be an effective strategy in localizing the response and energy expenditure. The sea star, Pisaster ochraceous, is a keystone species that inhabits the lower rocky intertidal zone of marine ecosystems where the local environment determines its body temperature. During aerial exposure, body temperatures of P. ochraceous often reach 8-10°C above ambient seawater, a level known to induce Hsp70, a hallmark of the CSR. Considering sea stars have a simple body plan with respect to their biological organization, it is possible that P. ochraceous is unable to integrate the mechanisms controlling the CSR and localize the synthesis of Hsp70. To gain better insight into the regulation of the CSR in P. ochraceous, we first characterized the plasticity of the heat shock response by measuring Hsp70 protein levels in stars acclimated to three different ecologically relevant temperatures. Additionally, we tested the ability of P. ochraceous to localize Hsp production using laboratory manipulations to thermally stress individual sea star arms. Overall, we hope to gain a better understanding of the potential energetic impacts a warming climate may have on this important intertidal species.
