Duda T F, Palumbi S R
Department of Organismic and Evolutionary Biology, Biological Laboratories, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, USA.
Proc Natl Acad Sci U S A. 1999 Jun 8;96(12):6820-3. doi: 10.1073/pnas.96.12.6820.
Predatory snails in the marine gastropod genus Conus stun prey by injecting a complex mixture of peptide neurotoxins. These conotoxins are associated with trophic diversification and block a diverse array of ion channels and neuronal receptors in prey species, but the evolutionary genesis of this functional diversity is unknown. Here we show that conotoxins with little amino acid similarity are in fact products of recently diverged loci that are rapidly evolving by strong positive selection in the vermivorous cone, Conus abbreviatus, and that the rate of conotoxin evolution is higher than that of most other known proteins. Gene duplication and diversifying selection result in the formation of functionally variable conotoxins that are linked to ecological diversification and evolutionary success of this genus.
海洋腹足纲芋螺属的掠食性蜗牛通过注入一种复杂的肽神经毒素混合物来使猎物昏迷。这些芋螺毒素与营养多样化相关，可阻断猎物物种中一系列不同的离子通道和神经元受体，但这种功能多样性的进化起源尚不清楚。在这里，我们表明，氨基酸相似性较低的芋螺毒素实际上是最近分化的基因座的产物，这些基因座在食虫芋螺（Conus abbreviatus）中通过强烈的正选择快速进化，并且芋螺毒素的进化速率高于大多数其他已知蛋白质。基因复制和多样化选择导致形成功能可变的芋螺毒素，这些毒素与该属的生态多样化和进化成功相关。
