Meeting Abstract
Understanding physiological tolerances of marine organisms to environmental stress is key to predicting species adaptability in a changing global climate, and when investigated, is most accurate under a multiple-environmental stressor approach. Congeners of the intertidal mussel genus Mytilus vary in their physiological tolerances to environmental stress. M. galloprovincialis, an invasive species from the Mediterranean, is overall more stress tolerant and can withstand elevated heat exposure, but it is vulnerable to hypo-salinity, while the native Pacific coast M. trossulus is more tolerant to hypo-saline conditions but vulnerable to heat stress. Recent findings suggest that sirtuins, a group of NAD+ dependent deacetylases, influence the environmental stressor tolerances in these two mussel species. Therefore, the purpose of this study was to investigate the combined effect of hypo-salinity and aerial heat stress on the proteome of M. galloprovincialis and M. trossulus while also investigating the role of sirtuins in influencing stress tolerance. Mussels were acclimated to tidal and circadian cycles for 3 weeks after which mussels were exposed to fully factorial combinations of salinity (34 or 29 ppt), aerial heat (18 or 32°C) and sirtuin inhibition (+/- suramin and nicotinamide) over the course of a 6 h high tide and 6 h low tide event. Gill tissue was collected after each stress exposure and following a 6 h recovery in control conditions (34 ppt, 18°C and no sirtuin inhibition). A preliminary analysis suggests that the congeners differ widely in how molecular chaperones of the endoplasmic reticulum respond to the combined exposure to heat and hypo-salinity.
