Learn the process by which a line of genetically modified mosquitoes was engineered to reduce populations of Aedes aegypti mosquitoes in the wild.

Viruses like Dengue, chickungunya, yellow fever, and Zika virus are spread by a species of mosquitoes called Aedes aegypti. To reduce the number of infections, health officials use various methods aimed at reducing mosquito populations. One of those methods is to produce genetically modified Aedes aegypti mosquitoes that, when released into the wild, reproduce with wild mosquitoes and cause their offspring to die. How is this accomplished? In this video, one of the scientists with the company Oxitec explains how they engineered mosquitoes to carry a “lethality” gene that prevents mosquito larvae from growing into adults unless they are fed the antibiotic tetracycline. The genetically modified mosquitoes were first produced in 2002 and bred in the lab to give rise to a colony of mosquitoes all dependent on tetracycline. This antibiotic—the antidote to the lethality gene—is available to the mosquitoes in the lab, but not in the wild. In 2015, male mosquitoes from this genetically modified colony were released in some areas of Brazil to help stop the spread of Zika virus.