Genetic architecture, spatial heterogeneity, and the coevolutionary arms race between newts and snakes.
Genetic architecture, spatial heterogeneity, and the coevolutionary arms race between newts and snakes.
复制标题
遗传结构、空间异质性以及蝾螈和蛇之间的共同进化军备竞赛。
DOI：
10.1101/2023.12.07.570693
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发表时间：
2024
期刊：
影响因子：
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通讯作者：
Ralph,PeterL
中科院分区：
文献类型：
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作者：
Caudill,Victoria;Ralph,PeterL
两个物种之间的共同进化可以导致夸张的表型，这些表型在空间上以相关的方式变化。然而，我们期望在多基因性状中这种空间变化的共同进化模式的条件尚未得到很好的理解。我们通过模拟Taricha蝾螈- Thamnophis吊袜带蛇系统，研究了两个物种在空间和时间上相互适应的共同进化动力学。从这个系统中得出的一个惊人的观察结果是，某些地区的蝾螈比其他地区携带更多的河豚毒素，而生活在毒性更强的蝾螈附近的袜带蛇往往对这种毒素更有抵抗力，这种相关性在几个广泛的地理区域都可以看到。此外，蛇似乎正在“赢得”共同进化军备竞赛，即，与当地蝾螈的毒性相比，蛇具有高水平的抗性，尽管在整个范围内毒性和抗性都存在很大差异。我们探索毒素和抗性性状的可能遗传结构如何通过在许多模拟中操纵突变的突变率和效应大小来影响共同进化动力学。我们发现，在我们的模拟中，单独的共同进化动力学不足以产生在自然界中观察到的惊人的毒性和抗性水平的马赛克，但是具有生态异质性（性状成本或相互作用率）的模拟确实产生了这样的模式。我们还发现，在模拟中，蝾螈倾向于在大多数遗传结构组合中“获胜”，尽管具有较高突变遗传变异的物种往往具有优势。
Coevolution between two species can lead to exaggerated phenotypes that vary in a correlated manner across space. However, the conditions under which we expect such spatially varying coevolutionary patterns in polygenic traits are not well-understood. We investigate the coevolutionary dynamics between two species undergoing reciprocal adaptation across space and time, using simulations inspired by the Taricha newt – Thamnophis garter snake system. One striking observation from this system is that newts in some areas carry much more tetrodotoxin than in other areas, and garter snakes that live near more toxic newts tend to be more resistant to this toxin, a correlation seen across several broad geographic areas. Furthermore, snakes seem to be “winning” the coevolutionary arms race, i.e., having a high level of resistance compared to local newt toxicity, despite substantial variation in both toxicity and resistance across the range. We explore how possible genetic architectures of the toxin and resistance traits would affect the coevolutionary dynamics by manipulating both mutation rate and effect size of mutations across many simulations. We find that coevolutionary dynamics alone were not sufficient in our simulations to produce the striking mosaic of levels of toxicity and resistance observed in nature, but simulations with ecological heterogeneity (in trait costliness or interaction rate) did produce such patterns. We also find that in simulations, newts tend to “win” across most combinations of genetic architectures, although the species with higher mutational genetic variance tends to have an advantage.