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In Florida and Texas, the invaders Aedes aegypti the mosquito posed a serious health threat, transporting the Zika virus and the dengue virus into the state. Traditional insecticides have been largely useless against mosquitoes. Outbreaks of Zika virus disease have been recorded in the Americas, Africa, Asia and the Pacific since the beginning of the epidemic in 2016, with more than half a million suspected cases and more 3,700 congenital anomalies. Puerto Rico saw more than 36,000 cases that year. The mainland of the United States had 224, and there is now a handful per year.
With the possibility of future outbreaks, the biotech company Oxitec has spent at least a decade testing a transgenic virus. A. aegypti with a gene that kills newly hatched mosquitoes before adulthood. In a recent field trial in Brazil, second-generation GM mosquitoes resulted in a 96% reduction in Zika carriers, Oxitec announced in June. Last week, the United States for Environmental Protection opened a one-month window to public comment on the company's proposal regarding releases to Florida and Texas.
Plans for the widespread release of genetically modified mosquitoes in the United States have met stiff resistance from anti-GMO organizations, who went door-to-door to elicit opposition four years ago in the Florida Keys. when the first tests were proposed. Since then, fears have disappeared. Local Floridians have divided responses into two surveys over the years, while other Florida surveys show significant public support. A tight referendum held in 2016 revealed that residents of Monroe County supported the press releases, with 31 out of 33 constituencies and 58% of residents in the country voting in favor of the Oxitec first generation mosquito project. Thousands of mosquitoes infected with Wolbachia bacteria were then released in the Florida Keys as part of a 12-week trial.
Activist environmental groups such as Friends of the Earth and Food and Water Watch, who described the liberation plans as "dangerously short-sighted," led the opposition in Texas and Florida. Oxitec expects feedback results and a subsequent decision from the EPA in the hope of obtaining authorization to field test 20,000 male mosquitoes per acre per week in these two states . These mosquitoes were designed to express a protein called tTAV-OX5034. The female offspring should die before reaching maturity, and therefore the A. aegypti the population should decrease, significantly, hopefully.
Has the mosquito experience gone bad?
A study by geneticist Jeffrey Powell, an insect population geneticist from Yale University, has wreaked havoc in these carefully crafted projects. Scientific reports. The title alone raised apocalyptic concerns: "The Aedes aegypti 
Mosquitoes transfer genes into a natural population. "
Powell and Brazilian researchers monitored the release by 450,000 men of Oxitec. A. aegypti mosquitoes in Jacobina, Brazil. The team genotyped the strain to release and the population of A. aegypti until 30 months after release. They reported that parts of the genome of the transgenic mosquito had been incorporated into the targeted Jacobina mosquito population.
Is it a concern or a potential disaster? After all, Oxitec had always estimated that about 3% of the offspring of modified mosquitoes survived, so the main finding was not surprising. But then researchers went beyond the data to speculate on the causes and potential implications.
[E]It is evident that the rare viable hybrids between the release strain and the Jacobina population are robust enough to reproduce in the wild. … The three populations forming the tri-hybrid population currently at Jacobina (Cuba / Mexico / Brazil) are genetically quite distinct, which will most likely result in a more robust population than the pre-seed population through hybrid vigor.
The research team seemed to have raised what many readers of the study saw as an apocalyptic interpretation of the data: had Oxitec just created a new "skeeter Franken?" And it was this speculation that caught the attention media, anti-GMO groups and more than a few critical scientists.
The anti-GM group, GMWatch, announced that the mosquitoes of the experiment had "escaped human control" and that they
is now spreading in the environment. Mosquitoes used for genetic manipulation come from Cuba and Mexico. These insects used in the laboratory have now mixed with Brazilian insects to become a robust population that can persist in the environment for a longer period.
Some reports reported that the study was simple, but many others mixed documentable scientific results (GM mosquitoes mixed with wild-type mosquitoes and A. aegypti appears to have rebounded after 18 months of suppression) with what many saw as wild speculation (that new hybrid mosquitoes may be more resistant to suppression and more likely to spread disease).
A ScienceAlert story (citing a New Atlas article titled "The genetic engineering experience of mosquitoes goes bad") illustrates this speculative coverage:
Genetically modified mosquitoes have mingled with the wild population and, for a brief period, the number of mosquitoes in Jacobino, Brazil, has collapsed, according to a study published in Nature Scientific Reports last week. According to New Atlas, 18 months later, the population has rebounded immediately, and even worse, the new genetic hybrids could be even more resistant to future attempts to reduce their numbers.
According to an article in the German news agency DPA, Christoph Then, president of the famous European anti-GMO organization Testbiotech:
Oxitec's tests resulted in a largely uncontrollable situation. This incident must have consequences for the future use of genetic engineering.
Scientists reacted quickly and abruptly to this speculation. Chad Niederhuth, Plant Geneticist, Michigan State University tweeted, "Some of the statements in this paper are completely unfounded and the title is downright irresponsible." Despite the title of the journal on the transfer of genes in a "natural population", Aedes aegypti is native to Africa and is an invasive species throughout the Western Hemisphere (including, of course, in Brazil).
Jason Rasgon, an entomologist and epidemiologist at Pennsylvania State University, dissected the problem of the document in more detail. In one series of tweets, as well as in a story Science magazine, Rasgon wrote:
- The experiment was not a failure because A. aegypti has decreased for 18 months, noting that "when you stop the releases, the pop returns to normal".
- The population genetics methods used by Powell's team showed that DNA from the strain to be released had been transferred to the "wild" population. This could be worrying if A. aegypti were from Brazil, which is not the case. And, as Henry Miller, a former FDA official (and founding director of the agency's biotechnology office) pointed out, the study showed that no part of the transgenic gene was transferred.
- The transmission capacity of the dengue virus was not changed (only the mosquito population), which was what Oxitec wanted (and previous studies had shown). "Even though there may be here a potentially interesting story in population genetics, there is no epidemiological significance."
- On the paper's assertion that hybridization would give "a more robust population than the pre-startup population," Rasgon pointed out (in capital letters) that "they present absolutely no evidence or given to supporting this statement ".
Rasgon and other scientists have begun to ask why these speculative findings figured in an otherwise solid article on the genetics of mosquito populations, why would a notable group of researchers make such statements and why? Scientific reports publish them.
Shortly after the publication of the newspaper, after a storm of criticism, the magazine (Nature Publishing) published this:
In the Talking Biotech podcast of the University of Florida's Kevin Folta, Kelly Matsen, head of research and development at Oxitec, said that the Aedes mosquito is invading the world and has resisted other efforts . The genetically based sterile insect technique of the company is moving away from traditional radiography / irradiation methods to genetically modify insects so that they can "have the effect of reducing populations, then "Remove genes from the environment when we finished our work," says Matsen.
Whatever the resolution of this problem, the document and its reaction illustrate the structure of the conflict around genetic modification: some scientists who advocate cautious use of technology, other victims of hype and speculation and organizations non-governmental organizations (NGOs) opposed such technology. As the GLP pointed out in a previous article, this opposition "is based on speculative risks, those for which no theory or evidence is established," according to Canadian researchers who interviewed experts on their perception of genetic modification.
Andrew Porterfield is a writer and publisher. He has worked with many academic institutions, companies and non-profit organizations in the life sciences field. ORGANIC. Follow him on Twitter @AMPorterfield
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