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Updated: Jun 6, 2025
Indel Detection following CRISPR/Cas9 Mutagenesis using High-resolution Melt Analysis in the Mosquito Aedes aegypti
Published on: September 10, 2021
Detection of the 1016Gly and 989Pro Knockdown Resistance Mutations in Florida, USA Aedes aegypti
Alden S Estep1, Neil D Sanscrainte1, Frieda Lamberg2
1Mosquito & Fly Research Unit, Center for Medical, Agricultural and Veterinary Entomology, United States Department of Agriculture, 1700 SW 23rd Drive, Gainesville, FL 32608, USA.
Abstract:
Aedes aegypti is a major arboviral disease vector and is therefore a critical target for control by public health programs. Early eradication efforts have shown that Ae. aegypti can rapidly build insecticide resistance, and, now, resistance to pyrethroids, the major class of adulticides used for operational control, is common in many populations. A major contributor to this resistance is a group of knockdown resistance (kdr) SNPs that normally exist in distinct ensembles in the Western Hemisphere and the Indopacific with little known mixing. In this study, we detected, and confirmed, using multiple methods, the Indopacific kdr SNPs, both V1016G and S989P, in three recent collections from Osceola County, Florida. This represents a large expansion of the geographic range of the Indopacific kdr SNPs. We consider the implications of this finding on future insecticide resistance surveillance studies, including assessing the ability of our current screening tools to detect these SNPs. We find that the presence of the Indopacific SNPs requires the modification of existing resistance screening protocols and requires further work to understand the operational implications for mosquito control.
Insights
The Indopacific knockdown resistance (kdr) SNPs, V1016G and S989P, were found in Florida mosquito populations. This geographic expansion necessitates updates to insecticide resistance surveillance and mosquito control strategies.
Area of Science:
- Entomology
- Molecular Biology
- Public Health
Background:
- Aedes aegypti mosquitoes are significant vectors of arboviruses, posing a global public health challenge.
- Insecticide resistance, particularly to pyrethroids, is a major obstacle in controlling Ae. aegypti populations.
- Knockdown resistance (kdr) single nucleotide polymorphisms (SNPs) are key genetic mechanisms conferring insecticide resistance.
Purpose of the Study:
- To detect and confirm the presence of Indopacific kdr SNPs in Florida mosquito populations.
- To assess the geographic expansion of these specific kdr SNP variants.
- To evaluate the implications for insecticide resistance surveillance and mosquito control.
Main Methods:
- Genomic DNA extraction from mosquito collections.
- Polymerase chain reaction (PCR) and sequencing to identify kdr SNP genotypes.
- Analysis of SNP distribution and frequency.
Main Results:
- The Indopacific kdr SNPs, V1016G and S989P, were detected in Ae. aegypti populations in Osceola County, Florida.
- This finding indicates a significant geographic range expansion for these specific kdr alleles.
- Current screening tools may require modification to accurately detect these SNPs.
Conclusions:
- The presence of Indopacific kdr SNPs in Florida highlights the dynamic nature of insecticide resistance evolution.
- Existing resistance surveillance protocols need to be updated to include these variants.
- Further research is crucial to understand the operational impact on mosquito control programs.
