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 (GM) 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 GM 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 GM colony were released in some areas of Brazil to help stop the spread of Zika virus. When male GM-mosquitoes mate with non-GM females in the wild, they pass on the lethality gene to the offspring who, without access to tetracycline, die before growing into adults.
The downloadable educator materials PDF document provides background information, discussion questions and responses as well as implementation suggestions. It has been remediated to comply with Section 508 of the National Rehabilitation Act for accessibility and can be used with screen readers.
Figure 1 from the educator materials is available as a separate downloadable pdf.