Meeting Abstract

P2.107  Tuesday, Jan. 5  Genetic Variation in the Alpha 1 subunit of the Na,K-pump in a Freshwater Serpent WILLIS, R.E.**; PRESSLEY, T.A.; Texas Tech University Health Sciences Center, Lubbock; Texas Tech University Health Sciences Center, Lubbock raymond.willis@ttuhsc.edu

The inability to tolerate changes in salinity restricts the ecological niche exploited by aquatic animals. Although it is clear that salinity acclimation depends primarily on specific changes in epithelial solute transport, these details have been identified in relatively few species. Recent observations of snake populations may provide an opportunity to observe the evolutionary transitions necessary to exploit a higher-salinity regime. The Florida cottonmouth (Agkistrodon piscivorus conanti) is a generalist feeder that typically consumes terrestrial, freshwater-aquatic, and carrion prey. A sub-population of snakes in Florida scavenges marine carrion in intertidal zones, and unavoidably ingests excess saltwater through the incidental consumption of accompanying detritus. This salinity tolerance likely has a genetic component, suggesting that there is a physiological specialization to eliminate the excess salt derived from ingestion of the incidental seawater. As the source of the driving force required for epithelial transport, the Na,K-pump is a likely target for any genetic variation accompanying salinity tolerance. To begin exploring the structure-function relationships responsible for this adaptation, we sequenced the alpha 1 isoform of the Na,K-pump in the kidney of the terrestrial western cottonmouth. We identified variations in the isoform specific region and surrounding residues that could potentially play a role in salinity acclimation. Funded in part by RR 19799 from the NIH.