Department of Biological Sciences, Old Dominion University, Norfolk, Virginia.
Division of Biological Sciences, University of California San Diego, La Jolla, California.
Evolution. 2018 Oct;72(10):2234-2243. doi: 10.1111/evo.13586. Epub 2018 Sep 11.
Viral gain-of-function mutations frequently evolve during laboratory experiments. Whether the specific mutations that evolve in the lab also evolve in nature and whether they have the same impact on evolution in the real world is unknown. We studied a model virus, bacteriophage λ, that repeatedly evolves to exploit a new host receptor under typical laboratory conditions. Here, we demonstrate that two residues of λ's J protein are required for the new function. In natural λ variants, these amino acid sites are highly diverse and evolve at high rates. Insertions and deletions at these locations are associated with phylogenetic patterns indicative of ecological diversification. Our results show that viral evolution in the laboratory mirrors that in nature and that laboratory experiments can be coupled with protein sequence analyses to identify the causes of viral evolution in the real world. Furthermore, our results provide evidence for widespread host-shift evolution in lambdoid viruses.
病毒功能获得性突变在实验室实验中经常进化。在实验室中进化的特定突变是否也在自然界中进化，以及它们对现实世界中的进化是否有相同的影响尚不清楚。我们研究了一种模型病毒，噬菌体 λ，它在典型的实验室条件下反复进化以利用新的宿主受体。在这里，我们证明 λ 的 J 蛋白的两个残基对于新功能是必需的。在天然 λ 变体中，这些氨基酸位点高度多样化，并且以高速度进化。这些位置的插入和缺失与表明生态多样化的系统发育模式相关。我们的结果表明，实验室中的病毒进化与自然界中的进化相吻合，并且可以将实验室实验与蛋白质序列分析相结合，以确定现实世界中病毒进化的原因。此外，我们的结果为 lambdoid 病毒中广泛存在的宿主转移进化提供了证据。
