Dissertation Research: Intra- and Interspecific Variability in Neurotoxin Resistance: A Study of Coevolution between Grasshopper Mice and Bark Scorpions

North Carolina State University, Raleigh NC

Investigators

Abstract

This study employs the southern grasshopper mouse (Onychomys torridus) and the bark scorpion (Centruroides exilicauda) as a model to test the hypothesis that interspecific interaction between a predator and a toxic prey will result in behavioral and physiological adaptations that mediate their interaction (i.e., coevolution). Intra- and interspecific patterns of variability in neurotoxin resistance in grasshopper mice will be compared with geographic variability in bark scorpion venoms. An enzyme-linked immunosorbent assay (ELISA) will be used to screen serum samples in wild populations of mice in order to detect and quantify antibodies that preferentially bind to the vertebrate neurotoxins in bark scorpion venom. Quantification of antibodies that bind neurotoxins would provide a tool for estimating the frequency and intensity of interaction between mice and scorpions in sympatric populations. This research represents the first attempt to understand, from an evolutionary perspective, the presence and complexity of vertebrate neurotoxins in the Centruroides complex.