New draft genomes assemblies of Blastocystis isolates from subtypes 1 and 8 confirm conserved synteny, transposable element diversity, and provide insights into pathogenic potential.

Blastocystis is a highly prevalent protist infecting both humans and a wide range of animal hosts. Despite its global distribution and frequent association with gastrointestinal symptoms infections, its pathogenicity remains controversial. In this study, we report the de novo genome assembly of Blastocystis subtype 1 strain AMC (ST1 AMC) and subtype 8 strain AMC (ST8 AMC) generated from Illumina paired-end reads. The haploid genome sizes were approximately 15 Mbp and 13.9 Mbp, with N50 values of 11.2 Kbp and 19.8 Kbp, and encoded 6603 and 5579 predicted genes, respectively. Comparative genomic analyses with previously annotated genome from ST1 strain NandII, ST4 strain WR1 and ST7 strain B revealed conserved gene synteny among subtypes, supported the putative pathogenic potential of Blastocystis, and highlighted the expansion of specific gene families previously described. In addition, we reported a high and variable abundance of transposable elements across Blastocystis genomes, suggesting a dynamic and plastic genome architecture that may contribute to genomic diversification and adaptation.