Biology subjects

Reed, E. M.

Publications and source records attributed to Reed, E. M..

3 recordsLinked to original sources

bioRxiv2026

Fine-scale landscape genomics show asymmetric patterns of gene flow for the invasive mosquito Aedes albopictus

Mosquito-borne viruses like dengue, Zika, and chikungunya pose increasing health risks in the United States due to the expanding range of Aedes albopictus, a highly invasive mosquito species that now has a global distribution. Aedes albopictus thrive in artificial containers associated with anthropogenic land use, allowing populations to reach high numbers in urban and suburban environments. While the global spread of Ae. albopictus has been well-characterized, the effects of heterogeneous urban landscapes on dispersal and gene flow at fine spatial scales remain unclear. This study analyzed the genetic connectivity of Aedes albopictus populations collected in Wake County, North Carolina in 2018. We used single nucleotide polymorphisms SNP data from double-digest restriction-enzyme associated DNA sequencing (ddRADseq), and examined genetic connectivity through principal component analysis (PCA) and genetic network analysis. We then evaluated migration and source sink dynamics using a Bayesian approach for SNP data (BA3-SNP). We found little evidence of genetic clustering or isolated populations of Ae. albopictus in Wake County, suggesting high gene flow between sites. Migration analysis demonstrated asymmetric gene flow from rural to urban regions within Wake County, with greater gene flow occurring between and within urban regions. These findings suggest that Ae. albopictus populations demonstrate substantial gene flow within local metropolitan areas, with urban city centers serving as genetic sinks and surrounding suburban and rural regions serving as sources. This study highlights how heterogeneous landscapes shape mosquito population connectivity and migration at fine spatial scales, which is critical for informing vector control and public health intervention strategies.

genetics↗

bioRxiv2025

Rapid spread of knockdown resistance allele frequencies in a suburban population of Aedes albopictus

Aedes albopictus is a major vector of arboviral diseases and is often targeted by pyrethroid-based mosquito control in residential areas. While knockdown resistance (kdr) mutations are well documented in Ae. aegypti, their emergence in Ae. albopictus has been less studied, particularly in suburban environments where insecticide application is often uncoordinated. Understanding the temporal and spatial dynamics of resistance evolution in this context is critical for preserving the effectiveness of public health interventions. We conducted longitudinal sampling of Ae. albopictus populations in Wake County, North Carolina, from 2016 to 2024. Using a novel allele-specific PCR melt curve assay, we genotyped 2,273 mosquitoes at the F1534S locus in the voltage-gated sodium channel gene. Resistance allele frequencies were calculated annually and mapped across the county for three key years--2016, 2018, and 2023-- representing the pre-emergence, initial detection, and widespread phases of resistance development. Selection and dominance were estimated using the Wright-Fisher Approximate Bayesian Computation algorithm for locus F1534S. The F1534S resistance allele was first detected in 2018 at a central, affluent neighborhood. By 2023, the allele had spread throughout the sampling region, with the highest frequencies near the site of first detection. Resistance allele frequency peaked at 0.36 in 2023, accompanied by an increase in heterozygous and homozygous resistance genotypes. Temporally sampled sites showed consistent trends in rising resistance, with all temporally-sampled locations harboring resistance genotypes by 2022. The resistance allele was found to be under high selection pressure and partially recessive in this population. Our findings reveal rapid emergence and spatial expansion of the F1534S kdr allele in Ae. albopictus populations in a suburban setting. The pattern of spread suggests strong local selection pressure, likely driven by residential pyrethroid use. These results highlight the need for proactive resistance monitoring and integrated management strategies that address private-sector contributions to insecticide selection pressure.

evolutionary biology↗

bioRxiv2025

Spatiotemporal variation in abundance and genetic structure across the urban-rural landscape gradient: Aedes albopictus (Skuse, 1894) (Diptera: Culicidae) in Wake County, NC

Since its invasion of the United States in the 1980s, Aedes albopictus (Skuse, 1894) has become a major pest and a significant public health threat in the Southeastern USA. Despite its importance, we know little about its population genetics at fine spatial scales. To remedy this lack of information, we analyzed Ae. albopictus spatial variation in mosquito abundance and genetic structure in an urban-rural landscape over two years (2016 and 2018) in Wake County, NC, USA. We used a reduced representation sequencing method to generate between 11,00 to 30,000 SNPs that were used for population genetic analyses. We found spatial variation in both the abundance, genetic diversity, and significant differences in genetic divergence among sites that varied between the two years. The year-to-year variation in the population genetic patterns at the within county scale suggests a dynamic system which requires extensive geographic, temporal, and genomic sampling to resolve. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=138 SRC="FIGDIR/small/659333v1_ufig1.gif" ALT="Figure 1"> View larger version (50K): org.highwire.dtl.DTLVardef@1158719org.highwire.dtl.DTLVardef@58ba77org.highwire.dtl.DTLVardef@139e303org.highwire.dtl.DTLVardef@166f334_HPS_FORMAT_FIGEXP M_FIG C_FIG

genetics↗