Ferric Reductase is a Key Factor in Regulating Iron Absorption by Blastocystis sp.

Purpose: This study aimed to identify and analyze the role of Ferric reductase inBlastocystis sp. subtype 2 (ST2) and explore the relationship between the parasite and iron metabolism.

Methods: The location of Ferric reductase in Blastocystis sp. was determined using the indirect immunofluorescence assay (IFA). Transmission electron microscopy was employed to reveal the effect of iron ions on the cell membrane of Blastocystis sp.. For the first time, RNA interference technology was used to explore the relationship between Ferric reductase and iron ions.

Results: Ferric reductase was distributed in the membrane and cytoplasm of the parasite. Iron reduces the thickness of the Blastocystis sp.'s cell membrane. After silencing the Ferric reductase gene, there was no significant difference in the morphology of the parasite strain compared with the control group. The expression level of the Ferric reductase gene does not play a decisive role in maintaining the morphology of the parasite, but the deletion of the Ferric reductase gene reduces the ability of the parasite to absorb iron ions.

Conclusions: This study fills the gap in the research field of iron metabolism inBlastocystis sp. among parasites, lays a foundation for the research on the gene function of Blastocystis sp., and provides new candidate factors for the development of Blastocystis sp. vaccines.