Whole genome sequencing and phylogenomic analysis of Clinostomum piscidium: Insights into pathogenicity and evolutionary relationships.

Clinostomum spp. (Trematoda: Clinostomidae) is a globally distributed parasite known to infect both fish and humans. Despite its significance, research on its genomic and taxonomic characteristics remains limited. This study focuses on the whole genome analysis of Clinostomum piscidium, building on prior investigations of the mitochondrial genome of Clinostomum complanatum. A comprehensive understanding of the parasite's genome will offer valuable insights into its epidemiology, biology, and genetic diversity. The draft genome assembly comprises 24,959 contigs and encodes 15,543 protein-coding genes, covering a total size of 316.66 Mb. Using eggNOG and BLAST databases for annotation, we identified 7084 genes associated with pathogen-host interactions (PHI), 1708 membrane transport proteins, and 235 carbohydrate-active enzyme (CAZy)-related genes. A phylogenomic analysis, performed using single-copy genes from BUSCO annotations, compared C. piscidium with closely related species in the Clinostomum genus and included Schistosoma mansoni as an outgroup. The resulting phylogenetic tree highlighted interspecies gene differences, with distinct branches forming within shared nodes, underscoring the evolutionary closeness within the genus. These findings contribute to a deeper understanding of the parasite's pathogenic mechanisms and lay the groundwork for future studies on the evolution and biology of the Clinostomum genus.