Sección Genética Evolutiva, Departamento de Biología Animal, Instituto de Biología, Facultad de Ciencias, Universidad de la República, Iguá 4225, 11400, Montevideo, Uruguay.
Escuela de Medicina Veterinaria y Zootecnia, Facultad de Ciencias Agropecuarias, Universidad Estatal de Bolıvar, Av. Ernesto Che Guevara s/n. Guaranda, Ecuador.
Virus Res. 2022 Oct 2;319:198858. doi: 10.1016/j.virusres.2022.198858. Epub 2022 Jul 7.
Canine distemper virus (CDV) is a Morbillivirus (Canine morbillivirus) that greatly impacts domestic and wildlife carnivores worldwide. The CDV RNA genome has high genetic variability, evidenced by several lineages that follow a global geographic pattern. The evolutionary trajectories and population dynamics of CDV lineages are still unclear and debatable, particularly in South America, where relatively few sequences are available. We performed phylogenetic and Bayesian analyses using an updated dataset of the highly variable hemagglutinin (H) gene, including seven South American countries. The time to the most recent common ancestor (tMRCA) of the current CDV lineages was dated to the early 1900s in North America. Maximum likelihood and Bayesian maximum clade credibility phylogenies showed similar topologies with two main branches (L1 and L2) corresponding to the NA1 lineage (L1) and the remaining lineages worldwide (L2). The four circulating lineages in South America (EU1/SA1, SA2, SA3, NA4/SA4) arose from independent migration events from North America and Europe. North American strains colonized most northern South American countries via Ecuador and then Colombia and Peru, originating the SA3 and NA4/SA4 lineages during their spread. The entry and expansion in the southern part of South America (Argentina, Brazil, Chile, and Uruguay) occurred through three independent migration events and gave rise to the EU1/SA1 and SA2 lineages. South American lineages have specific combinations of amino acids under positive selection that constitute signatures of taxonomic and evolutionary relevance. Our findings provide a comprehensive scenario for the origin and migration routes of Canine morbillivirus in South America and highlight the importance of phylodynamics in understanding the geographic patterns of modern genetic variability.
犬瘟热病毒（CDV）是一种麻疹病毒（犬麻疹病毒），对全球的家养和野生动物食肉动物有重大影响。CDV 的 RNA 基因组具有高度的遗传变异性，这一点可以从遵循全球地理模式的几个谱系中得到证明。CDV 谱系的进化轨迹和种群动态仍然不清楚，也存在争议，特别是在南美洲，那里可用的序列相对较少。我们使用包括七个南美国家在内的高度可变的血凝素（H）基因的更新数据集进行了系统发育和贝叶斯分析。当前 CDV 谱系的最近共同祖先（tMRCA）时间可追溯到 20 世纪初的北美。最大似然和贝叶斯最大分支可信度系统发育树显示出相似的拓扑结构，有两个主要分支（L1 和 L2），对应于北美 1 谱系（L1）和全球其余的谱系（L2）。南美的四个流行谱系（EU1/SA1、SA2、SA3、NA4/SA4）是由从北美和欧洲独立迁移事件引起的。北美毒株通过厄瓜多尔和哥伦比亚、秘鲁殖民了大多数南美洲北部国家，在传播过程中产生了 SA3 和 NA4/SA4 谱系。南美的南部（阿根廷、巴西、智利和乌拉圭）的进入和扩张是通过三个独立的迁移事件发生的，产生了 EU1/SA1 和 SA2 谱系。南美的谱系具有特定的氨基酸组合，这些氨基酸受到正选择的影响，构成了分类和进化相关性的特征。我们的研究结果为犬麻疹病毒在南美洲的起源和迁移路线提供了一个全面的情景，并强调了在理解现代遗传变异性的地理模式时，系统发育动力学的重要性。
