Meeting Abstract
Climate change has already resulted in range shifts of a variety of species, as well as changes in the timing of various phenological events. As climate change continues these biological effects will become more pronounced. This work concerns the effects of warming waters on the physiology and gene expression of blue mussels. The blue mussel species complex is comprised of the congeners Mytilus trossulus, M. edulis, and M. galloprovincialis, which form a biogeographic replacement series with respect to temperature. We focus on the cold-temperate M. edulis and the warm-temperate M. galloprovincialis, which are physiologically and genetically distinct, yet hybridize readily, forming extensive hybrid zones. Closely related, but physiologically distinct species make ideal systems for studying the impacts of climate change, and this system is especially valuable due to the presence of natural hybrids. In this study we sampled individuals from putatively pure populations on either side of a hybrid zone and acclimated them to either 15°C or 23°C for 14 days in order to evaluate the animals’ response to persistent, lower level warming. Feeding rate and respiration rate were recorded at the end of 14 days, and RNA was extracted from the gills for RNA-seq. We showed that, despite being in close geographic proximity these populations differentially respond to sub-lethal temperature challenges. We then conducted an exploratory analysis of the transcriptional responses of these populations to identify putative regulatory differences that may provide the basis of species-specific differences in physiological responses to chronic sublethal temperature challenges. Future studies will utilize hybrid individuals to assess the co-segregation of physiological and transcriptomic adaptations of these two species in relation to changing climate.
