Identification of a Neurotoxic Venom Component in the Tiger Rattlesnake, Crotalus tigris

Previous toxicological and immunology assays have strongly suggested that a neurotoxic component is present in the venom of the Tiger Rattlesnake, Crotalus tigris. However, there has been no direct identification of this neurotoxin. We obtained 18 blood samples from Arizona C. tigris and analyzed them by PCR and DNA sequencing using primers specific for the acidic and basic subunits of Mojave toxin. All 18 samples demonstrated the presence of both subunits. Venom collected from five of the 18 snakes that provided blood samples were additionally tested for the presence of Mojave toxin with monoclonal antibodies. These anti-Mojave toxin antibodies recognized all five venoms. We conclude that, at least for the Arizona snakes sampled, the neurotoxin in C. tigris is Mojave toxin. Additional sampling and testing is necessary to determine the complete geographic distribution of Mojave toxin and Mojave toxin subunits in C. tigris populations.