Genome-wide studies of Nyssorhynchus darlingi related to microgeographic dispersion and blood-seeking behavior.

In Brazil, malaria is concentrated in the Amazon Basin, where more than 99% of annual cases are reported. Weak but statistically significant stratification signatures were identified among subpopulations separated by distances of approximately 2 to 3 km. Genome-wide association studies (GWAS) were performed to compare indoor/outdoor biting behavior and dusk/dawn for blood. There was a statistically significant association between biting behavior and single nucleotide polymorphism (SNP) markers adjacent to cytochrome P450 CYP4H14, associated with insecticide resistance. A statistically significant association between blood draw periodicity and SNP markers adjacent to circadian cycle-associated genes was also observed. The data presented here suggest that low-coverage whole genome sequencing with adequate processing represents a powerful tool for genetically characterizing vector populations at a microgeographic scale in malaria transmission areas, as well as for genome-wide association studies. Females entering homes to have a blood meal may be related to a specific cyp4H14 allele and female blood-seeking timing is related to circadian rhythm genes.

Samples were collected in the municipality of Mâncio Lima, state of Acre, Brazil between 2016 and 2017. Different approaches using imputation and non-imputation of genotypes for data processing and low-coverage sequencing genotyping were performed. After genotyping the samples, a population stratification analysis was performed.

Project details

Vector Control

Apr 2022 — Sep 2022

Brazil