Population genomics of Plasmodium ovale species in sub-Saharan Africa.

Carey-Ewend, Kelly; Popkin-Hall, Zachary R; Simkin, Alfred; Muller, Meredith; Hennelly, Chris; He, Wenqiao; Moser, Kara A; Gaither, Claudia et al. · Nat Commun · 2024

basic_science · Level V

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Abstract

Plasmodium ovale curtisi (Poc) and Plasmodium ovale wallikeri (Pow) are relapsing malaria parasites endemic to Africa and Asia that were previously thought to represent a single species. Amid increasing detection of ovale malaria in sub-Saharan Africa, we present a population genomic study of both species across the continent. We conducted whole-genome sequencing of 25 isolates from Central and East Africa and analyzed them alongside 20 previously published African genomes. Isolates are predominantly monoclonal (43/45), with their genetic similarity aligning with geography. Pow shows lower average nucleotide diversity (1.8×10<sup>-4</sup>) across the genome compared to Poc (3.0×10<sup>-4</sup>) (p < 0.0001). Signatures of selective sweeps involving the dihydrofolate reductase gene have been found in both species, as are signs of balancing selection at the merozoite surface protein 1 gene. Differences in the nucleotide diversity of Poc and Pow may reflect unique demographic history, even as similar selective forces facilitate their resilience to malaria control interventions.

Medical subject headings