Discovery of malaria mosquito evolutionary paths could aid in vaccine

A Cornell University research team operating in sub-Saharan Africa recently found evidence of two different evolutionary paths in the immune systems of malaria mosquitoes living in neighboring groups.

To fight pathogens, the genes in animal immune systems may evolve in two primary fashions, according to If there are a wide variety of pathogens, they may evolve diverse forms of genes to fight them, or when there are only a few pathogens, they may evolve genes that specialize in common infections.

The Cornell researchers have discovered evidence of both of these strategies occurring in the same immune-defense genes in different subpopulations of the human malaria vector mosquito, Anopheles gambiae.

Their study, appearing in March in the open-access journal PLoS Bioloogy, is centered on a gene cluster called APL 1. The genes that make up APL 1 are a critical part of their defense against pathogens, including malaria, which makes mosquitoes sick, as well as humans.

"From a purely evolutionary biology perspective, seeing both of those patterns occur in a single gene is very unusual; it validates both models," Brian Lazzaro, the study's principal investigator, said, according to PhysOrg. Lazzaro is a Cornell associate professor of evolutionary genetics in the Department of Entomology.

"Finding this same pattern of evolution in different parts of the genome is unusual and suggests that the genes may be evolving in concert," Lazzaro said.

Lazzaro said that these genes could be important to vector biologists and public health officials because they might hold clues to effectively fighting malaria in humans.

"It's possible that the differences in genetic diversity could change disease transmission to humans by mosquitoes from these subpopulations, but there is no evidence of this so far. It could also change the susceptibility of these mosquitoes to other pathogens," Lazzaro said, according to