Results Here, we show that soft ticks of the Ornithodoros moubata group, the natural arthropod vector of ASFV, harbour African swine fever virus-like integrated (ASFLI)-elements corresponding to up to 10% (over 20 kb) of the ASFV genome. Through orthologous dating and molecular clock analyses, we provide data suggesting that integration occurred over 1.47 million years ago. Furthermore, our data indicate that these elements, showing high sequence identities to modern ASFV, are maintained in the tick genome to protect the tick from infection with specific ASFV-strains through RNA interference.
Conclusion We suggest that this mechanism of protection, shaped through many years of co-evolution, is part of an evolutionary virus-vector “arms race”, a finding that has not only high impact on our understanding of the co-evolution of viruses with their hosts but also provides a glimpse into the evolution of ASFV.
- African Swine Fever Virus
- phylogenetic analysis