Holding Matthew, Disharoon Dante, Haynes Laura, Paruchuri Bipin Chakravarthy, Pontius M Hao Hao, Golden Krista, Shavit Jordan A, Desch Karl, Ginsburg David, Gupta Anirban Sen, Cruz Yolanda, Drabeck Danielle H
Life Sciences Institute, University of Michigan, Ann Arbor, MI.
Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA.
bioRxiv. 2025 May 15:2025.01.21.634112. doi: 10.1101/2025.01.21.634112.
Interactions between predators and prey are often characterized by strong selection pressures that shape extreme physiological adaptations. Venom resistance in large-bodied South American opossums (Clade Didelphini) is a striking example, as these marsupials prey on venomous snakes and exhibit remarkable resistance to their venom. While resistance is well documented in Didelphini, relatively little is known about venom resistance in the smaller, more diverse members of Didelphidae, which inhabit the same regions and encounter the same predators. Here, we investigate venom resistance in the small-bodied opossum, through multi-level physiological assays, examining responses to purified venom components and whole venom from sympatric and allopatric vipers. Our results show resists venom-induced disruptions to blood coagulation, retains platelet function in the presence of platelet-disrupting venoms, and inhibits snake venom metalloproteinases. Unexpectedly, we find that von Willebrand Factor (VWF) requires increased shear force to elongate, a previously unknown aspect of opossum blood physiology that may contribute to venom resistance and may have relevance to human coagulopathies. These findings expand the extent of venom resistance beyond large-bodied Didelphini, suggesting it is a widespread trait in South American marsupials and providing new insights into venommammal coevolution.
捕食者与猎物之间的相互作用通常具有强大的选择压力，这些压力塑造了极端的生理适应性。大型南美负鼠（Didelphini分支）的抗毒液能力就是一个显著的例子，因为这些有袋动物以毒蛇为食，并且对它们的毒液表现出显著的抗性。虽然在Didelphini中抗毒液能力已有充分记录，但对于生活在同一地区并遭遇相同捕食者的、体型较小且种类更多的负鼠科成员的抗毒液能力，我们了解得相对较少。在这里，我们通过多层次的生理分析来研究小型负鼠的抗毒液能力，检测其对来自同域和异域蝰蛇的纯化毒液成分和全毒液的反应。我们的结果表明，[小型负鼠]能抵抗毒液引起的血液凝固紊乱，在存在破坏血小板的毒液时保持血小板功能，并抑制蛇毒金属蛋白酶。出乎意料的是，我们发现[小型负鼠的]血管性血友病因子（VWF）需要增加剪切力才能伸长，这是负鼠血液生理学中一个以前未知的方面，可能有助于抗毒液能力，并且可能与人类凝血障碍有关。这些发现将抗毒液能力的范围扩展到了大型Didelphini之外，表明这是南美有袋动物中的一个普遍特征，并为毒液-哺乳动物的协同进化提供了新的见解。
