Whole-genome analysis of one natural interspecific recombinant strain between bovine alphaherpesviruses 1 and 5

ROMERA S.A.; RUBEN PEREZ; ANA MARANDINO; ROCIO TAU; FABRICIO SOUZA CAMPOS; PAULO MICHEL ROEHE; ETIENNE THIRY; MAIDANA S. S

Congreso; 18th Ecology and Evolution of Infectious Diseases (online) meeting; 2021

BoHV-1 and BoHV-5 are closely related viruses that co-circulate in South America. Previous reports have shown that recombine in natural conditions. Here, we obtained the complete genome of A663 a natural recombinant virus between BoHV-1 and BoHV-5 by Illumina next generation sequencing. Genome was obtained with good average coverage (>1000) and submitted to the GenBank (Accession number MW829288). Complete genome sequence have size of approximately 138.3 kb and a GC content of 75%. The genome structure corresponds to the herpesvirus class D, whit 69 open reading frames (ORFs) arranged in the same order as in other bovine alphaherpesviruses. The genome were included in recombination network studies indicating statistically significant recombination evidence both based on the whole genome, as well as in the sub-regions. A new recombination event was found. The is of the 6637 nt and includes the UL13, UL12, UL11, UL10 and UL9 ORFs, it could have originated independently of the first event located in the gB and previously reported (Maidana et al, 2017). One recombinant breakpoint is within the reading frame of the helicase (UL9), originating a chimeric enzyme, 50% encoded by BoHV-5 and 50% by BoHV-1.2b. The identity with his parents is 96.8 and 96.3% for BoHV-5 and BoHV-1 respectively. In vitro characterization suggests that the recombinant virus have delayed exit from the cell compared to parental strains. However, It produce the same viral titer as their possible parents suggesting the accumulation of viral particles and the exit of the cell are only delayed on time. Despite the difference, the natural recombinant virus have been maintained in the bovine herd for more than 30 years, indicating that recombination could be playing an important role in the natural diversity of these viral species. These results highlights the importance of studying the diversity of natural viral populations at the level of complete genomes and determining the role that homologous recombination play in the structure of these viral populations that allows us to predict the evolutionary behavior of these viruses, thus detecting future threats to animal and human health.