Meeting Abstract
The multi-functional crustacean gill acts as the primary site for regulation of many physiological processes that allow for the wide environmental plasticity observed in crustaceans. Specifically, gills are the major organs responsible for osmoregulation, which allows euryhaline crustaceans to maintain elevated internal osmolality in dilute waters. In brachyuran decapods only the posterior gills are specialized for osmoregulation; anterior gills are undifferentiated and function in gas exchange. However, the molecular basis underlying this specialization is poorly understood. Furthermore, examination of salinity-induced gene expression in the gills is typically restricted to known ion transporters (e.g., Na+/K+-ATPase). Here we use an RNA-Seq based approach to characterize gene expression in response to salinity transfer in anterior and posterior gills of the blue crab (Callinectes sapidus), a well-studied model for crustacean osmoregulation. While confirming previous patterns of gene expression consistent with salinity transfer, we identified novel differentially expressed genes (DEGs) involved in ion transport, hormonal regulation, and energy metabolism/mitochondrial function in the posterior gills. Anterior gills were characterized by high levels of structural proteins such as actin, but showed few DEGs associated with osmoregulation. Publically available crustacean gill transcriptomes were also investigated in order to identify a “core” crustacean gill transcriptome. Finally, we use a subsampling strategy to make a recommendation as to the minimum number of reads necessary in studies of crustacean gill transcriptomics and ecophysiology. Results described here demonstrate the ease of applying transcriptomics to species with little or no available sequence data.
