Cipriani Vittoria, Debono Jordan, Goldenberg Jonathan, Jackson Timothy N W, Arbuckle Kevin, Dobson James, Koludarov Ivan, Li Bin, Hay Chris, Dunstan Nathan, Allen Luke, Hendrikx Iwan, Kwok Hang Fai, Fry Bryan G
Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia.
Venom Evolution Lab, School of Biological Sciences, University of Queensland, St Lucia, QLD 4072, Australia; Australian Venom Research Unit, Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, Victoria 3010, Australia.
Comp Biochem Physiol C Toxicol Pharmacol. 2017 Jul;197:53-60. doi: 10.1016/j.cbpc.2017.04.007. Epub 2017 Apr 27.
Venom is a key evolutionary trait, as evidenced by its widespread convergent evolution across the animal kingdom. In an escalating prey-predator arms race, venoms evolve rapidly to guarantee predatory or defensive success. Variation in venom composition is ubiquitous among snakes. Here, we tested variation in venom activity on substrates relevant to blood coagulation among Pseudonaja (brown snake) species, Australian elapids responsible for the majority of medically important human envenomations in Australia. A functional approach was employed to elucidate interspecific variation in venom activity in all nine currently recognised species of Pseudonaja. Fluorometric enzymatic activity assays were performed to test variation in whole venom procoagulant activity among species. Analyses confirmed the previously documented ontogenetic shift from non-coagulopathic venom in juveniles to coagulopathic venom as adults, except for the case of P. modesta, which retains non-coagulopathic venom as an adult. These shifts in venom activity correlate with documented ontogenetic shifts in diet among brown snakes from specialisation on reptilian prey as juveniles (and throughout the life cycle of P. modesta), to a more generalised diet in adults that includes mammals. The results of this study bring to light findings relevant to both clinical and evolutionary toxinology.
毒液是一种关键的进化特征，这在整个动物界广泛的趋同进化中得到了证明。在不断升级的猎物-捕食者军备竞赛中，毒液迅速进化以确保捕食或防御的成功。蛇类毒液成分的差异普遍存在。在这里，我们测试了伪眼镜蛇属（棕蛇）物种之间毒液在与血液凝固相关底物上的活性差异，这些澳大利亚眼镜蛇科蛇类导致了澳大利亚大多数具有医学重要性的人类中毒事件。我们采用功能方法来阐明目前已确认的所有九种伪眼镜蛇属物种毒液活性的种间差异。进行了荧光酶活性测定以测试不同物种全毒液促凝血活性的差异。分析证实了先前记录的从幼年时的非凝血性毒液到成年时的凝血性毒液的个体发育转变，但谦虚伪眼镜蛇除外，它成年后仍保留非凝血性毒液。毒液活性的这些转变与棕蛇饮食中记录的个体发育转变相关，从幼年时专门捕食爬行动物猎物（以及谦虚伪眼镜蛇的整个生命周期），到成年后更广泛的饮食，包括哺乳动物。这项研究的结果揭示了与临床和进化毒素学相关的发现。
