Mosquito does not spread malaria!How did they do it?

Text ｜ Xinyu

Gambia can carry the raw pyramids by mosquitoes. Image source: RealityImages/Shutterstock

British researchers have found that genetic modification of mosquitoes carrying malaria disease can slow down the development of malaria parasites in their body and shorten the life of mosquitoes. Finally, genetically modified mosquitoes will die before spreading malaria. Related research results were published in "Scientific Progress" published on September 21.

The thesis communication author and the British Empire Institute of Technology George Christophides said that laboratory research and computer models show that this method can prevent the spread of fatal parasites and eliminate malaria transmission.

It is worth noting that the key to the role of this method is genetic driving, that is, the genetic modification required for spreading in wild mosquitoes. This is a mechanism that can cause specific DNA fragments to be inherited by all offspring, and in general, genetic information can only be inherited in half. Gene drivers can spread specific DNAs in the population, even if it is unfavorable.

Christophides pointed out that the new study is based on the development of malaria parasites in mosquito and reaching the salivary glands for 10 to 12 days. Only after reaching the salivary glands can mosquito bite be infected. Therefore, the entire communication cycle can be destroyed by delaying the growth of parasites.

In order to do this, the research team carried out genetic modification of Gangbia according to mosquitoes, so that the intestinal cells secreted the two kinds of small protein that had previously proven to delay the development of parasites. One of the proteins comes from African claw frogs and the other comes from bees.

The results showed that after the genetically modified mosquito was infected, it took a few more days to detect malaria parasites on the head of the mosquito. More importantly, this change has shortened the life of mosquitoes for several days. Christophides said that this further reduced mosquito survival and infectious time.

Christophides also pointed out that there are still two potential problems in this method. With the spread of gene -driven, malaria parasites can be resistant to these two proteins. But the faster the parasitic population collapses, the lower the probability of drug resistance. Therefore, in order to avoid this situation, the genetic drivers that make mosquitoes spread as much as possible are particularly important.

Another problem is that the evolution of mosquitoes may prevent genetic drive from proceeding. Researchers said the design of gene -driven will minimize this risk.

Researchers in Tanzania are using this method to transform local mosquitoes to observe how this transformation has the effect of the effect of local malaria parasitic transmission. If the research is successful, the research team hopes to conduct field trials in Tanzania, but this work is currently limited to the laboratory.

In addition, other research teams are studying how to use genes to drive the elimination of mosquitoes. For example, let all female mosquito descendants infertility, and the male offspring maintains fertility and continues to spread gene drive. In Brazil, millions of genetically modified mosquitoes have been released to reduce the number of wild mosquitoes. These genetically modified mosquitoes carry a gene that can kill the offspring of any female mosquito mating with them. There is no evidence that this gene exists in wild animals.

Christophides said these two methods can be used together. One method can be used to eliminate mosquitoes in one area. Mosquitoes that survive or enter from another area can be genetically modified through another method to prevent them from spreading malaria.

Related thesis information:

https://doi.org/10.1126/sciadv.abo1733

"China Science News" (2022-09-23 The 2nd edition of the original title "Scientists cultivate mosquitoes that do not spread malaria")

Edit | Zhao Lu

Capture | Zhihai

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