Extensive Variation in the Activities of Pseudocerastes and Eristicophis Viper Venoms Suggests Divergent Envenoming Strategies Are Used for Prey Capture.

Affiliation

Op den Brouw B(1), Coimbra FCP(1), Bourke LA(1), Huynh TM(2), Vlecken DHW(3), Ghezellou P(4)(5), Visser JC(1), Dobson JS(1), Fernandez-Rojo MA(6)(7), Ikonomopoulou MP(6)(7), Casewell NR(8), Ali SA(9), Fathinia B(10), Hodgson WC(2), Fry BG(1).
Author information:
(1)Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
(2)Monash Venom Group, Faculty of Medicine, Nursing & Health Sciences, Monash University, Clayton, VIC 3800, Australia.
(3)Department of Animal Science and Health, Institute of Biology Leiden, 2333 BE Leiden, The Netherlands.
(4)Medicinal Plants and Drugs Research Institute, Shahid Beheshti University, 1983969411 Tehran, Iran.
(5)Institute of Inorganic and Analytical Chemistry, Justus Liebig University Giessen, 35392 Giessen, Germany.
(6)Madrid Institute for Advanced Studies in Food, E28049 Madrid, Spain.
(7)Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD 4072, Australia.
(8)Centre for Snakebite Research & Interventions, Liverpool School of Tropical Medicine, Liverpool L3 5QA, UK.
(9)HEJ Research Institute of Chemistry, International Centre for Chemical and Biological Sciences
(ICCBS), University of Karachi, Karachi 75270, Pakistan.
(10)Department of Biology, Faculty of Science, Yasouj University, 75914 Yasouj, Iran.

Abstract

Snakes of the genera Pseudocerastes and Eristicophis (Viperidae: Viperinae) are known as the desert vipers due to their association with the arid environments of the Middle East. These species have received limited research attention and little is known about their venom or ecology. In this study, a comprehensive analysis of desert viper venoms was conducted by visualising the venom proteomes via gel electrophoresis and assessing the crude venoms for their cytotoxic, haemotoxic, and neurotoxic properties. Plasmas sourced from human, toad, and chicken were used as models to assess possible prey-linked venom activity. The venoms demonstrated substantial divergence in composition and bioactivity across all experiments. Pseudocerastes urarachnoides venom activated human coagulation factors X and prothrombin and demonstrated potent procoagulant activity in human, toad, and chicken plasmas, in stark contrast to the potent neurotoxic venom of P. fieldi. The venom of E. macmahonii also induced coagulation, though this did not appear to be via the activation of factor X or prothrombin. The coagulant properties of P. fieldi and P. persicus venoms varied among plasmas, demonstrating strong anticoagulant activity in the amphibian and human plasmas but no significant effect in that of bird. This is conjectured to reflect prey-specific toxin activity, though further ecological studies are required to confirm any dietary associations. This study reinforces the notion that phylogenetic relatedness of snakes cannot readily predict venom protein composition or function. The significant venom variation between these species raises serious concerns regarding antivenom paraspecificity. Future assessment of antivenom is crucial.