Ancient recombination events between human herpes simplex viruses

Bibliographic Collection: 
Publication Type: Journal Article
Authors: Burrel, Sonia; Boutolleau, David; Ryu, Diane; Agut, Henri; Merkel, Kevin; Leendertz, Fabian H.; Calvignac-Spencer, Sébastien
Year of Publication: 2017
Journal: Molecular Biology and Evolution
Date Published: 03/28/ 2017
Publication Language: eng

Herpes simplex viruses 1 and 2 (HSV-1 and HSV-2) are seen as close relatives but also unambiguously considered as evolutionary independent units. Here, we sequenced the genomes of 18 HSV-2 isolates characterized by divergent UL30 gene sequences to further elucidate the evolutionary history of this virus. Surprisingly, genome-wide recombination analyses showed that all HSV-2 genomes sequenced to date contain HSV-1 fragments. Using phylogenomic analyses, we could also show that two main HSV-2 lineages exist. One lineage is mostly restricted to sub-Saharan Africa while the other has reached a global distribution. Interestingly, only the worldwide lineage is characterized by ancient recombination events with HSV-1. Our findings highlight the complexity of HSV-2 evolution, a virus of putative zoonotic origin which later recombined with its human-adapted relative. They also suggest that co-infections with HSV-1 and 2 may have genomic and potentially functional consequences and should therefore be monitored more closely.