Evolutionary and Population Genetics of Mosquito Disease Vectors
Mosquitoes are widely regarded as the deadliest animals on the planet because of the many diseases they vector. Malaria alone killed 429,000 people in 2015. To date, the most effective method at reducing the burden imposed by mosquito-borne illnesses is vector control. Traditional vector control strategies have largely relied on the use of chemical insecticides to reduce vector populations and ease disease burden. The most effective current methods continue to use insecticides, but they are being incorporated in programs known as integrated vector management that aim to incorporate multiple vector control strategies and closely monitor success and failures. Recent advances in genetic technology are now making it possible to modify and control vector populations via the introduction of genetic elements that will spread through the target population. While there has been great success in using insecticides and the use of genetic elements shows great promise, there is still much we do not yet know about vector evolution and population genomics. The following research projects fill in some of the gaps in our knowledge. We have modeled effective population size changes Aedes aegypti in response to the deployment of novel traps in Puerto Rico, generated fine-scale recombination rate maps for Anopheles gambiae, and reconstructed a genomic region of high divergence between An. gambiae and An. coluzzii to gain insight into the evolution of genes important in the modulation of the mosquito’s immune response to malaria infection. Our results indicate that despite success in An. gambiae, approximate Bayesian computation may not be an appropriate method for estimating effective population size in Ae. aegypti; we show that recombination rate in An. gambiae varies dependent on sex and the presence of chromosomal inversions; and we describe a previously unannotated gene in An. gambiae that may play an important role in mosquito immunity, as well as show that it arose as a chimera of two neighboring genes, much like another gene in this region. Taken together, these projects fill important holes in our knowledge of mosquito vector evolution and population genetics and will help inform future vector control strategies.