April 20, 2022
The first open-air study of genetically modified mosquitoes in the United States has yielded positive results, says Oxitec, the UK-based company that ran the study.
However, Oxitec says larger tests are needed to determine whether the insects can suppress the disease-spreading mosquito population in the wild, according to Nature. Dengue, Zika, and yellow fever are some of the diseases the experiments hope to reduce.
Scientists at Oxitec mass produced and genetically modified male Aedes aegypti mosquito eggs in a lab. The males were released into the wild to mate with females and pass along a gene designed to kill the female offspring, which are the only ones that bite and spread the diseases. The male offspring live on.
Researchers placed boxes of Oxitec mosquito eggs in Florida Keys and surrounded them with traps at a radius of 400 meters, Nature said. The males that hatched mated with female mosquitos and some females laid eggs in the traps, as well as in flower pots, rubbish-bin lids, and soft-drink cans.
The researchers collected more than 22,000 eggs that were observed in the laboratory, Nature reported. Hatching female mosquitoes that carried the lethal gene fluoresce under a certain light in the lab, making it easy to spot them, Nature said.
“The firm reported that all females that inherited the lethal gene died before reaching adulthood,” Nature said.
The gene that kills females stayed in the wild population for about three months, or three generations of mosquito offspring, then disappeared.
The next step is to conduct a larger trial to confirm if genetically modified mosquitoes actually reduce the wild mosquito population, Nature said.
As part of that expanded testing, the U.S. Environmental Protection Agency in March approved the release of 2 billion genetically altered mosquitoes in Florida and California.
The Florida Keys Mosquito Control District supports Oxitec’s experiments, Nature said.
“We’ve dealt with multiple disease outbreaks, so we’ve got to do everything we can to protect our people down here and the economy,” said Andrea Leal, executive director of FKMCD. “We’re looking at any tool that could be helpful.”
Oxitec has not published the results but announced them during an April 6 webinar.