Chromosome-scale genome of Schistosoma mekongi

Schistosoma mekongi is a human blood fluke causing schistosomiasis that threatens approximately 1.5 million humans. The limited available S. mekongi resources have hindered the understanding of its biology and parasite-host interactions for pathogen control. Here, we produced a high-quality reference genome with a size of ~404 Mb by integrating multiple technologies. Macrosynteny with local rearrangements was observed in Schistosoma genomes at the chromosome level. A comparative analysis of representative flatworms showed that proteases (cercarial elastase and leishmanolysin-like metalloproteases) were restricted to certain species or that lineage expansion in blood flukes had occurred via tandem duplication and divergence; these enzymes may be critical for successful skin penetration and blood feeding. In addition, we analyzed the transcriptomes of snails with miracidium infection and revealed increased expression of metabolic and biosynthetic activity-related genes after infection, which might be beneficial for cercaria production. The comprehensive genome presented here provides an unprecedented resource for understanding Schistosoma biology and will facilitate the development of schistosomiasis therapy.