Meeting Abstract

P1.144  Wednesday, Jan. 4  Comparative proteomic analysis of blood sera of venom-resistant and non-resistant ground squirrels under rattlesnake predation BIARDI, James; Fairfield University

Rattlesnake venoms produce a suite of effects, including hemorrhage, myotoxicity, hypovolemic shock, clotting disorders, edema, and paralysis. These arise from a complex mix of enzymatic and non-enzymatic toxins. Our work on California ground squirrels and others’ work on other mammals shows some prey are resistant to rattlesnake venoms. Most work has focused on snake venom metalloproteases (SVMP) and their inhibitors since this toxin class produces extensive hemorrhage and expose a larger volume of prey tissue to other venom components. However, we have little insight into the molecular basis of resistance to non-SVMP venom toxin classes. We have applied a biomarker discovery approach to identify aspects of prey sera proteomes correlated with resistance via 2DiGE analysis of California ground squirrel (Otospermophilus beecheyi) sera samples from one site with has a high density of snakes where squirrels show high resistance, and one site where rattlesnakes are rare and squirrels have low resistance. Eleven spots (78%) have been identified based on homology to proteins in the NCBI nr database. Four of five spots with 1.9 to 19.8–fold increased expression levels in resistant animals are isoforms of α 1-antitrypsin. The other nine identified to date represent serum proteins (albumin, transferrin, transthyretin) involved in osmotic regulation and transport. Protein spots not yet anaylzed span the range of 24.9 to -13.8–fold difference in volume. We predict that some, but not all, will reflect SVMPI based on the highlighted differences in regions of low pI and intermediate MW (upper left). To our knowledge, this is the first application of comparative proteomics to evaluate vertebrate responses to predation, and the first application of 2DiGE technology to ecological or evolutionary studies in non-human animals.