It was a cunning plan. All these mosquitos are carrying terrible diseases like dengue fever and Zika, so what if we fired back and gave the mosquitos terrible genetic diseases that decimated their populations? That would serve them right and also reduce their affliction of human populations.
Scientists made it so. They genetically modified swarms of mosquitos to carry a lethal gene, called the OX513A strain, and released them into the Brazilian wilderness to breed with, and taint the precious germ plasm of the native mosquitos.
In an attempt to control the mosquito-borne diseases yellow fever, dengue, chikungunya, and Zika fevers, a strain of transgenically modified Aedes aegypti mosquitoes containing a dominant lethal gene has been developed by a commercial company, Oxitec Ltd. If lethality is complete, releasing this strain should only reduce population size and not affect the genetics of the target populations. Approximately 450 thousand males of this strain were released each week for 27 months in Jacobina, Bahia, Brazil.
Wow. That’s almost 50 million genetically diseased male mosquitos. I hope the scientists said, “Fly, my pretties!” when they dispatched them on their devious mission.
It worked for a while. Mosquito numbers dropped. But then…
Genetic sampling from the target population six, 12, and 27–30 months after releases commenced provides clear evidence that portions of the transgenic strain genome have been incorporated into the target population. Evidently, rare viable hybrid offspring between the release strain and the Jacobina population are sufficiently robust to be able to reproduce in nature.
Uh-oh. Is anyone surprised?
Our data clearly show that release of the OX513A has led to significant transfer of its genome (introgression) into the natural Jacobina population of Ae. aegypti. The degree of introgression is not trivial. Depending on sample and criterion used to define unambiguous introgression, from about 10% to 60% of all individuals have some OX513A genome
They don’t know what effects these other genes will have on the mosquitos.
It is not known what impacts introgression from a transgenic strain of Ae. aegypti has on traits of importance to disease control and transmission. We tested OX513A and Jacobina before releases for infection rates by one strain each of the dengue and Zika viruses and found no significant differences. However, this is for just one strain of each virus under laboratory conditions; under field conditions for other viruses the effects may be different. Also, introgression may introduce other relevant genes such as for insecticide resistance. The release strain, OX513A, was derived from a laboratory strain originally from Cuba, then outcrossed to a Mexican population. The three populations forming the tri-hybrid population now in Jacobina (Cuba/Mexico/Brazil) are genetically quite distinct, very likely resulting in a more robust population than the pre-release population due to hybrid vigor.
Before their experiment, there was one known population of Ae. aegypti around Jacobina, and they understood the genetic properties of those animals and could predict the salutary effect of introducing their lethal gene there. Unfortunately for their clever plan, the mosquito vector used to introduce that gene also had all those other mosquito genes, which have also been introduced into the region, and now they have become three genetically distinct mosquito populations, and their response to the ‘lethal’ gene has become complex and unpredictable. Yikes. Unintended consequences are entirely predictable, not in detail, of course, but the general chaos is.
You know what else is predictable? This.
Oxitec, the company responsible for developing the GM mosquito strain discussed in this article, has contacted New Atlas claiming that the report cited in this article contains “false, speculative and unsubstantiated claims and statements about Oxitec’s mosquito technology.” Oxitec says it is currently working with the journal publishers, Nature Research, to remove or update the article, which now carries a disclaimer.
Clearly, it is the scientists who exposed this problem, not the corporation that released transgenic mosquitos, that have Meddled with the Primal Forces of Nature.
You have meddled with the primal forces of nature, Mr. Beale, and I won’t have it, is that clear?! You think you have merely stopped a business deal — that is not the case! The Arabs have taken billions of dollars out of this country, and now they must put it back. It is ebb and flow, tidal gravity, it is ecological balance! You are an old man who thinks in terms of nations and peoples. There are no nations! There are no peoples! There are no Russians. There are no Arabs! There are no third worlds! There is no West! There is only one holistic system of systems, one vast and immune, interwoven, interacting, multi-variate, multi-national dominion of dollars! petro-dollars, electro-dollars, multi-dollars!, Reichmarks, rubles, rin, pounds and shekels! It is the international system of currency that determines the totality of life on this planet! That is the natural order of things today! That is the atomic, subatomic and galactic structure of things today! And you have meddled with the primal forces of nature, and you will atone!
Let’s be clear here. The scientists behind OX513A haven’t created a monster, the humans of Jacobina don’t have to flee for their lives, they haven’t done something that creates immediate medical issues. No, what they’ve done is increased the genetic diversity of the mosquito population and made the problem of controlling them more complex for future management.
Benjamin R. Evans, Panayiota Kotsakiozi, Andre Luis Costa-da-Silva, Rafaella Sayuri Ioshino, Luiza Garziera, Michele C. Pedrosa, Aldo Malavasi, Jair F. Virginio, Margareth L. Capurro & Jeffrey R. Powell (2019) Scientific Reportsvolume 9, Article number: 13047.