Genome assembly and gene annotation of Babesia ovis Israeli strain (Piroplasmida: Babesiidae) using PacBio HiFi sequencing.

Babesia ovis is a unicellular parasite of sheep and goats transmitted by the tick Rhipicephalus bursa. B. ovis infection is widespread and can be lethal, and therefore there is need for a deeper understanding of its biology and pathogenesis. There is currently a single genome available for a clinical isolate of B. ovis, and no laboratory strains have been sequenced so far. In this study we have sequenced and assembled the genome of the Israeli laboratory strain of B. ovis using highly accurate long-read sequencing (PacBio HiFi). The resulting assembly has high contiguity, with the four largest contigs comprising 96% of the assembly and representing putative near-complete chromosomes. Annotation identified 3,549 genes, of which 3,046 (85.6%) could be functionally annotated. BUSCO analysis on the annotated genes revealed 95.5%, 98.8% and 100% completeness of the Aconoidasida, Apicomplexa, and Alveolata lineages, respectively. Comparative analysis with other annotated piroplasmida genomes reveals the vast majority of predicted genes clustered in orthogroups. The availability of a high-quality genome assembly for a tractable laboratory strain could prove impactful in unlocking more basic and applied research avenues to be pursued for this important parasite system.