School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, Republic of China.
MIVEGEC Maladies Infectieuses et Vecteurs: Ecologie, Génétique, Evolution et Contrôle, IRD L'Institut de Recherche pour le Développement, CNRS Centre National de Recherche Scientifique, Universitè de Montpellier, Montpellier, France.
J Virol. 2019 Nov 13;93(23). doi: 10.1128/JVI.01236-19. Print 2019 Dec 1.
Genetic recombination has frequently been observed in coronaviruses. Here, we sequenced multiple complete genomes of dromedary camel coronavirus HKU23 (DcCoV-HKU23) from Nigeria, Morocco, and Ethiopia and identified several genomic positions indicative of cross-species virus recombination events among other betacoronaviruses of the subgenus Embecovirus (clade A beta-CoVs). Recombinant fragments of a rabbit coronavirus (RbCoV-HKU14) were identified at the hemagglutinin esterase gene position. Homolog fragments of a rodent CoV were also observed at 8.9-kDa open reading frame 4a at the 3' end of the spike gene. The patterns of recombination differed geographically across the African region, highlighting a mosaic structure of DcCoV-HKU23 genomes circulating in dromedaries. Our results highlighted active recombination of coronaviruses circulating in dromedaries and are also relevant to the emergence and evolution of other betacoronaviruses, including Middle East respiratory syndrome coronavirus (MERS-CoV). Genetic recombination is often demonstrated in coronaviruses and can result in host range expansion or alteration in tissue tropism. Here, we showed interspecies events of recombination of an endemic dromedary camel coronavirus, HKU23, with other clade A betacoronaviruses. Our results supported the possibility that the zoonotic pathogen MERS-CoV, which also cocirculates in the same camel species, may have undergone similar recombination events facilitating its emergence or may do so in its future evolution.
冠状病毒经常发生基因重组。在此，我们对来自尼日利亚、摩洛哥和埃塞俄比亚的骆驼冠状病毒 HKU23（DcCoV-HKU23）的多个完整基因组进行了测序，并鉴定了几个基因组位置，这些位置表明在 Embecovirus 亚属的其他贝塔冠状病毒（A 组贝塔 CoV）之间存在跨种病毒重组事件。在血凝素酯酶基因位置鉴定到兔冠状病毒（RbCoV-HKU14）的重组片段。在刺突基因 3'端的 8.9 kDa 开放阅读框 4a 处也观察到了啮齿动物 CoV 的同源片段。非洲地区的重组模式存在地理差异，突出了在单峰驼中循环的 DcCoV-HKU23 基因组的镶嵌结构。我们的结果强调了在单峰驼中循环的冠状病毒的活跃重组，这也与其他贝塔冠状病毒（包括中东呼吸综合征冠状病毒（MERS-CoV））的出现和进化有关。基因重组在冠状病毒中经常发生，可能导致宿主范围扩大或组织嗜性改变。在这里，我们展示了地方性单峰驼冠状病毒 HKU23 与其他 A 组贝塔冠状病毒之间的种间重组事件。我们的结果支持了这样一种可能性，即同样在同一骆驼物种中循环的人畜共患病病原体 MERS-CoV 可能已经经历了类似的重组事件，从而促进了其出现，或者在未来的进化中也可能会经历类似的重组事件。
