Engineering Malaria Resistant Mosquitoes

Earlier this month, a paper was published in Nature, showing proof of concept of a gene drive mechanism that could allow genetically engineered mosquitoes to take over natural populations.

In order for disease resistant mosquitoes to propagate in the natural populations and pass their genes on to offspring at high rates. So called gene-drive mechanisms provide methods for single copies of genes in the organism to be passed on to offspring at higher than normal rates. Without such a mechanism, the engineered genes would require a very long time to spread through the population, and may never become ubiquitous in a population.

The Nature paper demonstrated a gene-drive system using the homing-endonuclease gene (HEG). This gene inserts a copy of itself in the genome to ensure that all offspring get the gene. Researchers engineered an HEG gene to breakup a green fluorescent protein present in the test population. By placing a small number of HEG mosquitoes in a population of fluorescent mosquitoes, researchers could determine the number of mosquitoes with the HEG gene by counting the number of mosquitoes that were not fluorescent. In a population containing 1% HEG mosquitoes, within 12 generations, 60% of the mosquitoes were HEG mosquitoes.

Malaria causes hundreds of thousands of deaths each year, and engineered mosquitoes that could not carry malaria could potentially reduce this cause of death dramatically, as well as that of many other mosquito carried diseases.

http://news.sciencemag.org/sciencenow/2011/04/disease-proof-mosquito-could-spr.html?ref=hp