Humanity’s Victory over the Deadliest Creatures
We often find ourselves ambushed by these deadly creatures. They can sense our blood from up to 50 meters away and flap their wings 800 times per second towards us—their meal. Only a barely perceptible sound, produced by the beating of their wings, warns us of their approach, but by then, it is often too late. With each bite, they inject their nasty saliva into our bodies, causing our skin to swell and itch—but that is not all. They are also responsible for 52 billion human deaths over the span of 200,000 years. These 7-millimeter-long, 7-days-living, and nonemotional creatures—known to us as mosquitoes—infect more than 390 million people with the dengue virus, spread chikungunya, yellow fever, and Zika virus to thousands more, and cause over a million deaths each year.
Between 1945 and 1972, humanity, armed with DDT, an insecticide once used to control the spread of insects, waged a war against mosquitoes. However, humanity only succeeded at temporarily eradicating mosquitoes because they quickly developed resistance to DDT through natural selection. Furthermore, in 1972, the EPA banned the use of DDT after an accumulation of research that showed the harmful impact of DDT on wildlife and human beings. Lingering in the environment and animal tissues, DDT provoked chromosomal and reproductive abnormalities in both animals and human beings. Consequently, mosquitoes were the victors in the first battle.
However, humanity, now armed with more powerful weapons—self-limiting gene and male-selecting gene—is a more formidable adversary for the deadly creatures. Oxitec, a biotech company, developed these weapons to fight infectious mosquitoes—female Aedes aegypti mosquitoes. These mosquitoes not only pierce our skin with their needle-like mouths called proboscis and delight in the taste of our blood but also spread deadly diseases.
The self-limiting gene and male-selecting gene become weaponized once injected into male Aedes aegypti mosquitoes. When a male carrying the self-limiting gene mates, all of the offspring die before maturity, and when a male carrying the male-selecting gene mates, all of the female offspring die before maturity and half of the male offspring inherit the gene. The male offspring inherit the gene for ten generations and have the same lethal effect on the mosquito populations. In both cases, the genes prevent maturity of offspring by disrupting the proper functioning of cells by over-producing a protein and hindering the transcription of essential proteins.
The technology has repeatedly proven its effectiveness for Aedes aegypti mosquitoes and innocuousness for human beings and the ecosystem. In fact, in 2009, Oxitec reduced 80% of the Aedes aegypti mosquito in the Cayman Islands, and in 2015, it reduced 95% of the Aedes aegypti mosquitoes in Juazeiro, Brazil. In 2021, even the EPA, recognizing these attributes of the technology, allowed Oxitec to test it in the Florida Keys. While scientists still need to do more research to understand the full consequences of eradicating Aedes aegypti mosquitoes, humanity can finally claim its freedom from the mosquitoes’ vexing high-toned warnings, the itch-causing bites, and the deadly viruses they transmit.
Bibliography
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Danilo. “Suppression of a Field Population of Aedes Aegypti in Brazil by Sustained Release of Transgenic Male Mosquitoes.” PLOS Neglected Tropical Diseases, 2 July 2015, https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0003864.
Cahalan, Susannah. Forget Sharks — Mosquitoes Are the Deadliest Maneaters on Earth. 3 Aug. 2019, https://nypost.com/2019/08/03/forget-sharks-mosquitoes-are-the-deadliest-maneaters-on-earth/ .
Oxitec LTD. https://www.oxitec.com/en/news/oxitec-transitioning-friendly-self-limiting-mosquitoes-to-2nd-generation-technology-platform-paving-way-to-new-scalability-performance-and-cost-breakthroughs#:~:text=Oxitec’s%202nd%20generation%20insect%20technology,wild%2Dty.