Retel Cas, Kowallik Vienna, Becks Lutz, Feulner Philine G D
Department of Fish Ecology and Evolution, Center for Ecology, Evolution and Bio-geochemistry, EAWAG, Swiss Federal Institute of Aquatic Science and Technology, Seestrasse 79, Kastanienbaum 6047, Switzerland.
Department of Evolutionary Ecology, Community Dynamics Group, Max Planck Institute for Evolutionary Biology, August-Thienemann-Str. 2, Plön, Schleswig-Holstein 24306, Germany.
Virus Evol. 2022 Jan 25;8(1):veac003. doi: 10.1093/ve/veac003. eCollection 2022.
Characterizing how viruses evolve expands our understanding of the underlying fundamental processes, such as mutation, selection and drift. One group of viruses whose evolution has not yet been extensively studied is the , a globally abundant family of aquatic large double-stranded (ds)DNA (dsDNA) viruses. Here we studied the evolutionary change of chlorella virus 1 during experimental coevolution with its algal host. We used pooled genome sequencing of six independently evolved populations to characterize genomic change over five time points. Across six experimental replicates involving either strong or weak demographic fluctuations, we found single nucleotide polymorphisms (SNPs) at sixty-seven sites. The occurrence of genetic variants was highly repeatable, with just two of the SNPs found in only a single experimental replicate. Three genes and showed an excess of variable sites, providing new information about potential targets of selection during -Chlorovirus coevolution. Our data indicated that the studied populations were not mutation-limited and experienced strong positive selection. Our investigation highlighted relevant processes governing the evolution of aquatic large dsDNA viruses, which ultimately contributes to a better understanding of the functioning of natural aquatic ecosystems.
描述病毒如何进化有助于我们深入理解潜在的基本过程，如突变、选择和漂变。有一类病毒的进化尚未得到广泛研究，即噬藻体，它是全球分布广泛的水生大型双链（ds）DNA病毒家族。在这里，我们研究了小球藻病毒1与其藻类宿主在实验性共同进化过程中的进化变化。我们对六个独立进化的群体进行了混合基因组测序，以表征五个时间点的基因组变化。在涉及强或弱种群波动的六个实验重复中，我们在67个位点发现了单核苷酸多态性（SNP）。遗传变异的出现具有高度重复性，只有两个SNP仅在一个实验重复中被发现。三个基因显示出过量的可变位点，为噬藻体与宿主共同进化过程中潜在的选择靶点提供了新信息。我们的数据表明，所研究的群体不受突变限制，并经历了强烈的正选择。我们的研究突出了控制水生大型dsDNA病毒进化的相关过程，这最终有助于更好地理解天然水生生态系统的功能。
