It's going to be summer again, and one of the insects that everyone hates the most, mosquitoes, is about to start ravaging again. They come out day and night, sometimes biting out several bags overnight, making people itch and can't sleep. Sometimes, they can also spread disease and even cause death.
We all wish there were fewer insects, but someone in the United States took the initiative to cultivate a large number of mosquitoes to put into nature!
In 2020, a biotech company from the U.K. called Oxitec dropped millions of mosquitoes in Florida and Texas, and despite repeated protests from local residents, the U.S. Environmental Protection Agency agreed to the project. In 2021, another 144,000 mosquitoes were stocked on the Florida Keys in the United States! According to the plan, the total number of mosquitoes released locally is even more than 1 billion!
The mosquitoes they stocked were not from nature, but genetically modified mosquitoes that had been modified by humans. They hope that through this group of genetically modified mosquitoes, the insect will disappear.
In addition to the United States, Brazil, Panama, the Cayman Islands and Malaysia and other countries and regions have had similar experiments, but the United States is the only open-air experimental site.
According to biological classification, mosquitoes belong to the insect class, diptera, and mosquitoes, and there are 3 genera under them, namely Anopheles, Culex and Aedes. The genetically modified mosquito studied by Oxitec is the Aedes aegypti mosquito in the genus Aedes aedes.
Aedes aegypti mosquitoes are widely distributed around the world, mainly living in tropical and subtropical regions, such as Africa, Central and South America, Australia, Southeast Asia and other regions. On the mainland, Guangdong, Guangxi, Hainan and other areas south of 22° north latitude have Aedes aegypti activity.
This mosquito is best at carrying infectious diseases, such as dengue fever, yellow fever, Zika virus, encephalitis, etc., which are very powerful infectious diseases that take the lives of countless people every year. Therefore, the Aedes aegypti mosquito has also become the public enemy of all mankind, and we want to eliminate it, not only to prevent physical itching, but also to save a large number of lives.
According to the Florida Department of Health, there were no cases of dengue fever in the state for 75 years, from 1934 to 2009. However, in 2009 and 2010 alone, there were 88 cases of infection in key West, the state. There are also data showing that Aedes aegypti mosquitoes account for about 4% of the local mosquito population, but it causes 100% of mosquito-borne diseases.
Experts point out that these mosquitoes are very difficult to control. This is easy to understand, otherwise mosquitoes would not have ravaged for so many years. Also, pesticides may not work, as mosquitoes can develop resistance.
So there are companies like Oxitec that are trying to use genetically modified technology to eliminate these mosquitoes. Despite repeated protests by local people and opposition from some non-profit organizations, the local government approved such projects.
Technicians genetically engineered the cultured male Aedes aegypti mosquitoes to carry a special gene, infertility. Their plan is to breed large numbers of sterile male Aedes aegypti mosquitoes and then release them into nature to "plague" female Aedes aegypti mosquitoes. After the female has met the need for mating, she no longer needs to mate. When it is time to lay eggs, they will find out with a confused face: the children they give birth to are inherently defective, and the "girls" do not grow up!
If there are only male mosquitoes in nature, then the species will have difficulty mating. Over time, the number of newly born Aedes aegypti mosquitoes in nature will become smaller and smaller, and the number will be significantly controlled. The company did not make wild claims about the complete elimination of the Aedes aegypti mosquito. According to their plan, they hope to reduce the local Aedes aegypti by half, which can greatly control its population, and the majority of male mosquitoes do not bite humans, naturally reducing the spread of related diseases.
To verify the effect of the experiment, the researchers also installed a number of devices in the local area to collect adult mosquitoes and mosquito eggs. The results showed that after these genetically modified mosquitoes grew into adults, their behavior and flight range were basically the same as those of mosquitoes in nature. It turns out that female mosquitoes in nature really can't tell whether the opposite sex on the other side has undergone genetic modification and will perform indiscriminate mating to produce mosquito eggs.
Studies of mosquito eggs have shown that the modified genes did play the intended role. Of the more than 22,000 mosquito eggs collected, only the hatched male mosquitoes can grow into adulthood, while the female mosquitoes die prematurely and cannot grow up to mate.
According to a report published in the journal Nature, this modified gene can only last 2-3 months, which is almost three generations for mosquitoes. Moreover, these genetically modified mosquitoes were only found within 400 meters of the drop-off point.
According to Nathan Rose, Oxitec's head of corporate regulatory affairs, this data is basically in line with their original expectations, and this experiment has once again verified the self-limiting nature of genes and will not remain in nature permanently.
From the perspective of eliminating mosquitoes, GM means do have some effect. Previously, Brazil had carried out a small-scale stocking of genetically modified mosquitoes, and the results showed that the local Aedes aegypti population had dropped sharply by 95%, and the effect was very significant.
As for whether this experiment has significantly affected the spread of related diseases, it is still impossible to confirm. This is because the spread of these diseases in the United States is not very wide, and the data volume is relatively small, and even if there are only a few Aedes aegypti mosquitoes in some areas, there is a possibility of large-scale transmission of related diseases.
In the future, Oxitec will continue to carry out relevant experiments, and it is expected to release 2 billion genetically modified mosquitoes in Florida and Texas in the next two years! We certainly expect mosquito-borne diseases to be contained, but we also hope that there will be no surprises along the course of this experiment. After all, there's so much more to be learned about for humans when it comes to genes. #美国释放转基因蚊子 #