Comprehensive evolutionary analysis of complete Epstein Barr virus genomes from Argentina and other geographies

Abstract

Epstein Barr virus sequence variability has been deeply studied throughout the past years in isolates from various geographic regions and consequent geographic variation at both genetic and genomic levels has been described. However, isolates from South America have been underrepresented in these studies. Here, we sequenced 15 complete EBV genomes that we analyzed, by means of a custom-built bioinformatic pipeline, together with publicly available raw NGS data for 199 EBV isolates from other parts of the globe. Phylogenetic relations of the genomes, geographic structure and variability of the data set, and evolution rates for the whole genome and each gene were assessed. The present study contributes to overcome the scarcity of EBV complete genomes from South America, and hence, achieves the most comprehensive geography-related variability study by determining the actual contribution of each EBV gene to the geographic segregation of the entire genomes. Moreover, to the best of our knowledge, we established for the first time the evolution rate for the entire EBV genome, on a host-virus codivergence-independent assumption, and statistically demonstrate that evolution rates, on a gene-by-gene basis, are related to the encoded protein function. Considering evolution of dsDNA viruses with a codivergence-independent approach, may lay the basis for future research on EBV evolution. Additionally, this work also expands the sampling-time lapse of available complete genomes derived from different EBV-related conditions, a matter that until today, prevents for detailed phylogeographic analysis.