How Are Mosquitoes Made?
WouterBiologically, mosquitoes are part of the order Anopheles. They’re blood-feeding insects that carry and spread many diseases, including dengue, chikungunya and Zika. But researchers have recently discovered how to genetically modify these insects to make them more resistant to disease. These so-called gene-drive mosquitoes are being released in the wild for the first time in the United States.
In order to control mosquito populations, scientists have programmed male Aedes aegypti eggs to carry a gene that makes the female infertile. The gene is called tTAV, or tetracycline-repressible transcriptional activator variant. The protein binds to other genes and drives them to be expressed. When an organism produces too much tTAV, it dies.
The tTAV gene is the same one that’s in Oxitec’s mosquitoes. These insects grow up consuming tetracycline, which blocks tTAV activity. The protein is designed to drive the expression of other genes, but it can also create a dangerous feedback loop.
Until now, the only areas where gene-drive mosquitoes have been released in the United States are the Florida Keys and Panama. But the United States Environmental Protection Agency has authorized testing of modified mosquitoes in four counties in California. EPA officials hope that the data from the Oxitec trial will help them determine whether or not to release the insects in the US.
Oxitec is a British biotechnology company that hopes to reduce the spread of mosquito-borne illnesses. Their mission is not to kill mosquitoes, but to prevent people from getting sick. They are planning to release around 20 million mosquitoes in the Keys over a few months. They have been working with the local community in the Keys to build relationships and get their opinion.
