Biology subjects

Burford Reiskind, M. O.

Publications and source records attributed to Burford Reiskind, M. O..

5 recordsLinked to original sources

bioRxiv2026

Evidence of selection in sympatry between two closely related species of rockfish

Ecological or reproductive barriers can maintain species boundaries by preventing introgression in closely related taxa when their distributions overlap (sympatry). In sympatry, sister-taxa may have greater genetic divergence compared to allopatric parts of their range. When analyzing populations of one of the sister-taxa, this divergence may translate to greater genetic differentiation between sympatric and allopatric populations of this species range. This genetic differentiation can be caused by either genetic drift or natural selection, depending on the evolutionary history of secondary contact. To identify a selective process, it is critical to find genes responsible for maintaining species barriers in sympatry. Here, the role of natural selection in genetic differentiation was examined within two recently diverged rockfish species, Sebastes diaconus and Sebastes mystinus. These species overlap along over 400 km of coastline in the eastern Pacific, with no evidence of hybridization in this sympatric region. This study found evidence of geographic genetic differentiation across a large span of the S. diaconus range, but not within the S. mystinus range. For both species, outlier loci were identified that were associated with regions of the genome under directional selection in allopatric versus sympatric populations. This study also found signals of directional selection in shared genomic regions of both species, including in genes involved in neurological function, photoreception, and gene regulation. This suggests that the evolutionary process of reinforcement maintains species boundaries when the two species come into secondary contact.

genomics↗

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

Gonadal Transcriptome Differences Between the Sexes in Wild Caught Southern Flounder (Paralichthys lethostigma) During a Critical Development Period

Flounder in the genus Paralichthys exhibit a unique sex determination system that combines genotypic and temperature-dependent mechanisms. In southern flounder (Paralichthys lethostigma), XY individuals develop as males, while XX individuals sex is influenced by juvenile developmental temperatures. Little is known about the genes involved in this process. This study uses pooled RNA sequencing to create a de novo gonadal transcriptome and identify genes related to sex determination and differentiation in wild-caught juvenile southern flounder from two North Carolina locations with differing sex ratios. The transcriptome assembly revealed 68,331 uniquely annotated genes with high functional specificity. Nine genes were linked to sex determination, including five novel to southern flounder and associated with epigenetic mechanisms like m6a methylation and alternative splicing, suggesting epigenetic influence in male development. Additionally, genes in the TGF-{beta} signaling pathway were differentially expressed, supporting this pathways role in sex differentiation. This study provides a valuable transcriptome resource for future research on southern flounder.

evolutionary biology↗

bioRxiv2025

Socioeconomic predictors of knockdown resistance in Aedes albopictus (Diptera: Culicidae)

Knockdown resistance (kdr) in the mosquito Aedes albopictus (Skuse) jeopardizes the effectiveness of insecticidal control. This is a pressing issue given the expanding range of the species and its role as vector to harmful viruses. Effectively preventing the emergence of resistance or removing the conditions that positively select for kdr mutations requires us first to understand how these conditions arise. Here, we investigate the association between wealth and the frequency of kdr in Ae. albopictus populations in Raleigh, North Carolina, USA. We hypothesized that kdr frequency correlates with wealth, measured by total property value. We speculate that wealthier neighborhoods apply chemical insecticides more frequently, leading to higher kdr frequencies. We tested this hypothesis by sampling mosquito populations from 31 different residential blocks across the city and along a property value gradient. We found a high frequency of 39.0% for mutations at locus F1534S of the voltage-gated sodium channel gene (vgsc). Kdr mutations were found at 84% of the blocks we sampled. Our statistical analysis indicates strong evidence for an association between wealth and F1534S frequency. We discuss these and other findings, and what this means for suburban mosquito control going forward.

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↗