Nuclear, mitochondrial, and Wolbachia endosymbiont genomes of Onchocerca lupi, Portugal

Zoonotic Onchocerca lupi (Spirurida, Onchocercidae) has attracted the interest of the scientific community worldwide, by causing severe ocular infections in domestic animals (dogs, cats) and can infect wild carnivores (wolves, coyotes), as well as humans. Though recent advancements in scientific knowledge have been gained, gaps still remain about the biology of this filarioid, as well as its genetic structure. Based on mitochondrial genes, two highly divergent genotypes were identified, in the Iberian Peninsula (genotype 2) and Europe, Asia, and the United States (genotype 1), meanwhile only a draft nuclear genome of O. lupi from the United States is available. This study aimed to fill knowledge gaps about the genomic characterization of this filarioid and its Wolbachia endosymbiont. This study described the shotgun sequencing of an adult specimen of O. lupi isolated from a dog living in Portugal using the PacBio long-read sequencing technology. Three distinct genomes, such as the nuclear, mitochondrial, and Wolbachia endosymbiont, were assembled and analyzed. The assembled nuclear genome, Olupi_PT2024, exhibited high contiguity, accuracy, and completeness. Pairwise mitogenome comparative analyses among several Onchocerca species corroborated the high divergence between the two genotypes from Portugal and the USA, although the observed differences remained within the range of intra-species variation. The complete genome of the Wolbachia endosymbiont of O. lupi confirmed its classification within supergroup C and its close phylogenetic relationship with Wolbachia endosymbionts associated with the genus Onchocerca. The data on these three genomes may provide valuable resources for understanding the biology, population genetics, and phylogeography of this parasite.