Mapping structural variations in Haemaphysalis longicornis and Rhipicephalus microplus reveals vector-pathogen...

As the most common vector only second to mosquitoes, ticks pose an increasing threat to public health and cause economic losses. However, the genomic variations of ticks remain largely unknown. Here, we conducted the first whole-genome sequencing-based analysis of structural variation (SV) to understand the biology and evolution of ticks. We identified 8,370 and 11,537 SVs in 156 Haemaphysalis longicornis and 138 Rhipicephalus microplus, respectively. Different from the close relationship of H. longicornis, R. microplus can be clustered into three distinct geographic populations. We also identified a 5.2-kb deletion in cathepsin D gene in R. microplus and a 4.1-kb duplication in the CyPJ gene in H. longicornis; both are likely associated with vector-pathogen adaptation. Our study provided a whole-genome SV map and identified SVs associated with the development and evolution of tick species, which could be candidates for the prevention and control of ticks.