Biology subjects

Popkin-Hall, Z. R.

Publications and source records attributed to Popkin-Hall, Z. R..

3 recordsLinked to original sources

bioRxiv2025

Evidence of dengue virus transmission and a diverse Aedes mosquito virome on the Democratic Republic of Congo-Angola border

Aedes mosquitoes are widely distributed across the Democratic Republic of Congo (DRC), and are major vectors of dengue (DENV), Zika, chikungunya (CHIKV), and yellow fever (YFV) viruses. While the high burden of malaria in the DRC receives considerable attention, arboviruses remain understudied. In the setting of recent CHIKV and YFV outbreaks in southwestern DRC, we collected Aedes mosquitoes in three areas of Kimpese, DRC, near the Angola border, to investigate their virome. Metagenomic and targeted sequencing of eight randomly selected field mosquito pools, comprising 155 mosquitoes from three collection sites, confirmed high-confidence DENV reads and human blood meals in six (75%) and eight (100%) pools, respectively. We find diverse mosquito viromes including other known and putative human and animal viruses. Our findings provide strong evidence of endemic DENV transmission along the DRC-Angola border and illustrate the potential of wild-caught mosquitoes for xenosurveillance of emerging pathogens.

microbiology↗

bioRxiv2024

Molecular Evolution of Gustatory Receptors in the Anopheles gambiae Species Complex

BackgroundMosquitoes in the Anopheles (An.) gambiae species complex are major vectors of Plasmodium falciparum malaria. One reason for this is the high anthropophily of the constituent species An. coluzzii, An. gambiae sensu stricto, and An. arabiensis. In contrast, their sister species An. quadriannulatus is highly zoophilic. Anopheles mosquitoes largely rely on chemical cues for host-seeking, which are primarily detected by four chemosensory gene families: olfactory receptors (Ors), ionotropic receptors (Irs), gustatory receptors (Grs), and odorant binding proteins (Obps). Genes from these families that have been implicated in host adaptation show evidence of positive selection in other insect species, including other mosquitoes. As such, we analyzed the molecular evolutionary patterns of the gustatory receptors within the Anopheles gambiae complex, with a particular interest in identifying Grs that show evidence of positive selection in highly anthropophilic species. ResultsWe identified sixteen Grs that show evidence of potential positive selection using the McDonald-Kreitman test, including four putative sugar receptors and two Grs with unknown ligands that are relatively highly expressed in chemosensory organs of either An. coluzzii or An. quadriannulatus. In addition, we identified twelve Grs that show evidence of potential purifying selection using the McDonald-Kreitman test, and twelve Grs that may have experienced a selective sweep using the DH test, including three putative sugar receptors and the carbon dioxide receptor Gr24. We also identified both positive and purifying selection in the coastal species An. melas (West Africa) and An. merus (East Africa). ConclusionsOur results, together with transcriptomic data, identify four Grs as possible candidates for involvement in the evolution of vertebrate host preference in the An. gambiae complex, as may have occurred in the An. farauti complex. They also point to sugar receptors as playing a role in recent adaptation of some of these species. As the vast majority of Grs have unknown functions and much is still unknown about the role of Grs in these species, a more complete interpretation of our data necessitates further characterization of these genes.

evolutionary biology↗

bioRxiv2024

Population genomics of Plasmodium ovale species in sub-Saharan Africa

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 performed 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 were predominantly monoclonal (43/45), with their genetic similarity aligning with geography. Pow showed lower average nucleotide diversity (1.8x10-4) across the genome compared to Poc (3.0x10-4) (p < 0.0001). Signatures of selective sweeps involving the dihydrofolate reductase gene were found in both species, as were 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.

genomics↗