Reassortment between Influenza B Lineages and the Emergence of a Coadapted PB1-PB2-HA Gene Complex
Reassortment between Influenza B Lineages and the Emergence of a Coadapted PB1-PB2-HA Gene Complex
复制标题
DOI：
10.1093/molbev/msu287
复制
发表时间：
2015-01-01
影响因子：
10.7
通讯作者：
Rambaut, Andrew
中科院分区：
文献类型：
--
作者：
Dudas, Gytis;Bedford, Trevor;Rambaut, Andrew
流感B病毒对季节性流感的发病率做出了相当大的贡献。已知目前流行的B型流感分离株属于两种抗原性不同的谱系，称为B/维多利亚和B/Yamagata。过去已经注意到这两个谱系的基因组片段的频繁交换，但观察到的重配模式尚未详细正式化。我们通过比较基因组片段的系统发育树来研究谱系间的关系。我们的分析表明，在B型流感病毒的8个片段中，只有编码聚合酶碱性1和2（PB 1和PB 2）和血凝素（HA）蛋白的片段保持了独立的维多利亚和山形谱系，目前流行的毒株具有完全来自一个或另一个谱系的PB 1、PB 2和HA片段;其他片段在谱系之间反复重排，从而减少了遗传多样性。我们认为，片段之间的这种差异是由于针对具有混合谱系PB 1、PB 2和HA片段的重配病毒的选择造成的。如果有足够的时间和持续的招募到再培养分离的PB 1-PB 2-HA基因复合物中，我们预计B型流感病毒最终会经历同域物种形成。
Influenza B viruses make a considerable contribution to morbidity attributed to seasonal influenza. Currently circulating influenza B isolates are known to belong to two antigenically distinct lineages referred to as B/Victoria and B/Yamagata. Frequent exchange of genomic segments of these two lineages has been noted in the past, but the observed patterns of reassortment have not been formalized in detail. We investigate interlineage reassortments by comparing phylogenetic trees across genomic segments. Our analyses indicate that of the eight segments of influenza B viruses only segments coding for polymerase basic 1 and 2 (PB1 and PB2) and hemagglutinin (HA) proteins have maintained separate Victoria and Yamagata lineages and that currently circulating strains possess PB1, PB2, and HA segments derived entirely from one or the other lineage; other segments have repeatedly reassorted between lineages thereby reducing genetic diversity. We argue that this difference between segments is due to selection against reassortant viruses with mixed-lineage PB1, PB2, and HA segments. Given sufficient time and continued recruitment to the reassortment-isolated PB1-PB2-HA gene complex, we expect influenza B viruses to eventually undergo sympatric speciation.