Chromosome-level genome assembly of Cryptosporidium parvum by long-read sequencing of ten oocysts.

Cryptosporidium parvum is a zoonotic parasite of the intestine and poses a threat to human and animal health. However, it is difficult to obtain a large number of oocysts for genome sequencing using in vitro culture. To address this challenge, we employed the strategy of whole-genome amplification of 10 oocysts followed by long-read sequencing and obtained a high-quality genome assembly of C. parvum IIdA19G1 subtype isolated from a pre-weaning calf with diarrhea. The assembled genome was 9.13 Mb long and encompassed eight chromosomes with six capped by telomeric sequences at one or both ends. In total, 3,915 protein-coding genes were predicted, exhibiting a high completeness with 98.2% single-copy BUSCO genes. To our current knowledge, this represents the first chromosome-level genome assembly of C. parvum achieved through the combined use of whole-genome amplification of 10 oocysts and long-read sequencing. This achievement not only advances our understanding of the genomic landscape of this zoonotic intestinal parasite, but also provides valuable resources for comparative genomics and evolutionary analyses within the Cryptosporidium clade.