Adaptive evolution of the venom-targeted vWF protein in opossums that eat pitvipers.
Adaptive evolution of the venom-targeted vWF protein in opossums that eat pitvipers.
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DOI：
10.1371/journal.pone.0020997
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发表时间：
2011
期刊：
影响因子：
3.7
通讯作者：
Voss RS
中科院分区：
文献类型：
--
作者：
Jansa SA;Voss RS
毒液毒素基因的快速进化通常被解释为有毒动物与其猎物之间的生化军备竞赛的结果。然而，目前尚不清楚军备竞赛的类比在这方面是否合适，因为没有公开的证据表明，基因的快速进化可能会使经常被下毒的物种产生毒素抗性。在这里，我们报告这样的证据，从一个不寻常的捕食者-猎物之间的关系负鼠（有袋目：Didelphidae）和pitvipers（蛇：响尾蛇亚科）。特别是，我们发现在编码血管性血友病因子（vWF）（一种毒液靶向止血血液蛋白）的基因中，有很高的替换与沉默替换比率，这种基因存在于一种负鼠的进化枝中，这种负鼠已知吃蝰蛇，并对它们的出血性毒液有抵抗力。在抗蛇毒负鼠中观察到的氨基酸取代包括净电荷和疏水性的变化，这些变化被假设为减弱vWF与其毒性蛇毒配体之一C型凝集素样蛋白Botrocetin之间的键合。我们的研究结果提供了第一个在任何毒液靶向分子中快速适应性进化的例子，它们支持了进化军备竞赛可能推动蛇毒快速进化的观点。然而，在我们的研究结果所暗示的军备竞赛中，毒蛇是猎物，它们的毒液除了通常的营养作用外，还具有相应的防御功能。
The rapid evolution of venom toxin genes is often explained as the result of a biochemical arms race between venomous animals and their prey. However, it is not clear that an arms race analogy is appropriate in this context because there is no published evidence for rapid evolution in genes that might confer toxin resistance among routinely envenomed species. Here we report such evidence from an unusual predator-prey relationship between opossums (Marsupialia: Didelphidae) and pitvipers (Serpentes: Crotalinae). In particular, we found high ratios of replacement to silent substitutions in the gene encoding von Willebrand Factor (vWF), a venom-targeted hemostatic blood protein, in a clade of opossums known to eat pitvipers and to be resistant to their hemorrhagic venom. Observed amino-acid substitutions in venom-resistant opossums include changes in net charge and hydrophobicity that are hypothesized to weaken the bond between vWF and one of its toxic snake-venom ligands, the C-type lectin-like protein botrocetin. Our results provide the first example of rapid adaptive evolution in any venom-targeted molecule, and they support the notion that an evolutionary arms race might be driving the rapid evolution of snake venoms. However, in the arms race implied by our results, venomous snakes are prey, and their venom has a correspondingly defensive function in addition to its usual trophic role.
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影响因子：
2.9
作者：
DAVIE, EW;FUJIKAWA, K;KISIEL, W
通讯作者：
KISIEL, W
影响因子：
5.7
作者：
Fukuda, K;Doggett, TA;Liddington, RC
通讯作者：
Liddington, RC
DOI：
10.1098/rspb.1979.0081
发表时间：
1979-01-01
期刊：
PROCEEDINGS OF THE ROYAL SOCIETY SERIES B-BIOLOGICAL SCIENCES
影响因子：
--
作者：
DAWKINS, R;KREBS, JR
通讯作者：
KREBS, JR
影响因子：
10.7
作者：
Fry, BG;Wüster, W
通讯作者：
Wüster, W
影响因子：
2.9
作者：
BARCHAN, D;OVADIA, M;FUCHS, S
通讯作者：
FUCHS, S