babesia MO1 genome sequencing and assembly. Babesia sp. MO1

This babesia species, linked to several severe cases of human babesiosis in midwestern United States, was previously determined to be closely related to B. divergens, the major agent of human babesiosis in Europe. However, it remained uncertain whether these two pathogens are different variants of the same species or if they belong to entirely separate species. Here we provide evidence that this pathogen represents a separate species of Babesia that infect humans. We found that although both species share similar genome sizes, comprising three nuclear chromosomes, one linear mitochondrial chromosome, and one circular apicoplast chromosome, they exhibit significant differences in gene functions, transcriptional and epigenetic regulations, replication rates, and susceptibility to antiparasitic drugs. Additionally, both species express distinct classes of multigene families, which are likely crucial for their adaptation to the mammalian host.