Inversion Genotyping in the Anopheles gambiae Complex Using High-Throughput Array and Sequencing Platforms

Area of Science:

• Genetics
• Entomology
• Malaria vector research

Background:

• Chromosomal inversions are crucial for adaptation and range expansion in Anopheles gambiae mosquitoes.
• Traditional polytene chromosome analysis is limited by specialist availability, low throughput, and sampling restrictions.

Purpose of the Study:

• To develop and validate molecular genotyping methods using tag single nucleotide polymorphisms (SNPs) to determine chromosomal inversion status.
• To compare the accuracy and efficiency of molecular genotyping against traditional cytogenetic karyotyping.

Main Methods:

• Ascertainment of tag SNPs highly correlated with inversion status.
• High-throughput molecular genotyping of 960 Anopheles gambiae and Anopheles coluzzii mosquitoes.
• Comparison with traditional cytogenetic karyotyping using samples from Burkina Faso.

Main Results:

• Both molecular genotyping approaches demonstrated high accuracy, comparable to or exceeding traditional cytogenetics.
• Molecular methods provide results with similar accuracy regardless of mosquito sex or developmental stage.
• The tag SNP approach is scalable and cost-effective.

Conclusions:

• Molecular genotyping via tag SNPs offers a powerful, accessible tool to study chromosomal inversions in malaria vectors.
• This approach can revitalize research on the role of inversions in Anopheles gambiae adaptation to diverse environments.
• Enables large-scale population studies without the constraints of traditional cytogenetics.