PDF(Pubmed)
Abstract：
Severe fever with thrombocytopenia syndrome virus (SFTSV) poses a significant public health challenge in East Asia, necessitating a deeper understanding of its evolutionary dynamics to effectively manage its spread and pathogenicity. This study provides a comprehensive analysis of the genetic diversity, recombination patterns, and selection pressures across the SFTSV genome, utilizing an extensive dataset of 2041 sequences from various hosts and regions up to November 2023. Employing maximum likelihood and Bayesian evolutionary analysis by sampling trees (BEAST), we elucidated the phylogenetic relationships among nine distinct SFTSV genotypes (A, B1, B2, B3, B4, C, D, E, and F), revealing intricate patterns of viral evolution and genotype distribution across China, South Korea, and Japan. Furthermore, our analysis identified 34 potential reassortments, underscoring a dynamic genetic interplay among SFTSV strains. Genetic recombination was observed most frequently in the large segment and least in the small segment, with notable recombination hotspots characterized by stem-loop hairpin structures, indicative of a structural propensity for genetic recombination. Additionally, selection pressure analysis on critical viral genes indicated a predominant trend of negative selection, with specific sites within the RNA-dependent RNA polymerase and glycoprotein genes showing positive selection. These sites suggest evolutionary adaptations to host immune responses and environmental pressures. This study sheds light on the intricate evolutionary mechanisms shaping SFTSV, offering insights into its adaptive strategies and potential implications for vaccine development and therapeutic interventions.
摘要：
严重发热伴血小板减少综合征病毒（SFTSV）在东亚构成了重大的公共卫生挑战，需要更深入地了解其进化动力学，以有效地管理其传播和致病性。本研究提供了一个全面的遗传多样性分析，重组模式，以及整个SFTSV基因组的选择压力，利用截至2023年11月来自各种宿主和地区的2041个序列的广泛数据集。通过采样树(BEAST)采用最大似然和贝叶斯进化分析，我们阐明了9种不同SFTSV基因型之间的系统发育关系(A，B1,B2,B3,B4,C,D,E,andF),揭示了中国各地病毒进化和基因型分布的复杂模式，韩国,和日本。此外，我们的分析确定了34种潜在的重组，强调SFTSV菌株之间的动态遗传相互作用。基因重组在大段中最常见，在小段中最少。具有以茎环发夹结构为特征的显着重组热点，表明基因重组的结构倾向。此外,对关键病毒基因的选择压力分析表明负选择的主要趋势，RNA依赖性RNA聚合酶和糖蛋白基因内的特定位点显示阳性选择。这些位点表明了对宿主免疫反应和环境压力的进化适应。本研究揭示了塑造SFTSV的复杂进化机制，提供对其适应性策略以及对疫苗开发和治疗干预的潜在影响的见解。
