National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894, USA.
National Center for Biotechnology Information, National Library of Medicine, Bethesda, MD 20894, USA; Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, USA.
Cell Host Microbe. 2022 Jul 13;30(7):917-929. doi: 10.1016/j.chom.2022.06.008.
Viruses are obligate intracellular parasites. Despite their dependence on host cells, viruses are evolutionarily autonomous, with their own genomes and evolutionary trajectories locked in arms races with the hosts. Here, we discuss a simple functional logic to explain virus macroevolution that appears to define the course of virus evolution. A small core of virus hallmark genes that are responsible for genome replication apparently descended from primordial replicators, whereas most virus genes, starting with those encoding capsid proteins, were subsequently acquired from hosts. The oldest of these acquisitions antedate the last universal cellular ancestor (LUCA). Host gene capture followed two major routes: convergent recruitment of genes with functions that directly benefit virus reproduction and exaptation when host proteins are repurposed for unique virus functions. These forms of host protein recruitment by viruses result in different levels of similarity between virus and host homologs, with the exapted ones often changing beyond easy recognition.
病毒是专性细胞内寄生虫。尽管它们依赖宿主细胞，但病毒在进化上是自主的，它们拥有自己的基因组和进化轨迹，与宿主进行着军备竞赛。在这里，我们讨论了一种简单的功能逻辑来解释病毒的宏观进化，这种逻辑似乎定义了病毒进化的过程。一小部分负责基因组复制的病毒标志性基因显然源自原始复制子，而大多数病毒基因，从编码衣壳蛋白的基因开始，随后从宿主中获得。其中最早的获得发生在最后一个普遍的细胞祖先（LUCA）之前。宿主基因捕获有两种主要途径：直接有利于病毒繁殖的功能基因的趋同招募和当宿主蛋白被重新用于独特的病毒功能时的适应性进化。这些病毒对宿主蛋白的招募形式导致病毒与宿主同源物之间的相似性程度不同，适应性进化的宿主蛋白通常变化很大，难以识别。
