Anopheles gambiae strain:N'Gousso Random survey. Anopheles gambiae strain:N'Gousso

Anopheles gambiae is a major mosquito vector of malaria in Africa. While increased use of insecticide-based vector control tools have decreased malaria transmission, elimination is likely to require novel genetic control strategies. It can be argued that the absence of an An. gambiae inbred line has slowed progress towards genetic vector control. In order to empower genetic studies and enable precise and reproducible experimentation, we created an inbred line of this species. After full-sib inbreeding for 10 generations, we genotyped 112 individuals – 56 saved prior to inbreeding and 56 collected after inbreeding – at a genome wide panel of SNPs. While inbreeding dramatically reduced diversity across much of the genome, we discovered numerous, discrete genomic blocks that maintained high heterozygosity. Inbred lines in other eukaryotes often exhibit a qualitatively similar retention of polymorphism when typed at a small number of markers. Our whole genome SNP data provides the first strong, empirical evidence supporting associative overdominance as the mechanism maintaining higher than expected diversity in inbred lines. While creation of An. gambiae lines devoid of nearly all polymorphism may not be feasible, our results provide critical insights into how more fully isogenic lines can be created.