Genetic differentiation among Aedes aegypti populations from different eco-geographical zones of India

Abstract

The present study explicitly evaluated the genetic structure of Aedes aegypti Linn, the vector of dengue, chikungunya, and Zika viruses, across different geo-climatic zones of India and also elucidated the impact of ecological and topographic factors. After data quality checks and removal of samples with excess null alleles, the final analysis was performed on 589 individual samples using 10 microsatellite markers. Overall findings of this study suggested that, Ae. aegypti populations are highly diverse with moderate genetic differentiation between them. Around half of the populations (13 out of 22) formed two genetic clusters roughly associated with geographical regions. The remaining nine populations shared genetic ancestries with either one or both of the clusters. A significant relationship between genetic and geographic distance was observed, indicating isolation by distance. However, spatial autocorrelation analysis predicted the signs of long-distance admixture. Post-hoc environmental association analysis showed that 52.7% of genetic variations were explained by a combination of climatic and topographic factors, with latitude and temperature being the best predictors. This study indicated that though overall genetic differentiation among Ae. aegypti populations across India is moderate (Fst = 0.099), the differences between the populations are developing due to the factors associated with geographic locations. This study improves the understanding of the Ae. aegypti population structure in India that may assist in predicting mosquito movements across the geo-climatic zones, enabling effective control strategies and assessing the risk of disease transmission.

Effect of environmental conditions on the wing morphometric variation inAedes aegypti(Diptera: Culicidae) in India

“…To navigate the challenges posed by these dynamic settings, the mosquito must cope with significant selective pressures. Previous research has highlighted the varying impacts of distinct environmental conditions on mosquitoes, influencing their genetics (Sumitha et al, 2023), physiology (Sharma et al, 2023), and morphology (Hounkanrin et al, 2023). Expanding the existing knowledge, the present study analyzed the wing morphometrics of 11 Ae.…”

“…Consequently, diverse ecological and geographical conditions lead to changes in Ae. aegypti mosquito in context to their morphology, behavior, and genetics (Louise et al, 2015; Sumitha et al, 2023; Sharma et al, 2023).…”

“…aegypti population is considered the best effective management strategy to prevent the expansion of vector-borne diseases, making an understanding of population dynamics important. Population dynamics studies related to behavior and genetics, provide vital information about how mosquitoes react in different environments (Barrera et al, 2011; Grech et al, 2015; De et al, 2022; Sharma et al, 2023; Sumitha et al, 2023).…”

“…It is evident that Ae. aegypti have invaded all these climatic regions, having different genetics (Sumitha et al, 2023) and behavioral differences (Sharma et al, 2023) in India, leading to the hypothesis that there will be a significant difference in the wing morphometrics. Thus, a collection of Ae.…”