Mosquitoes with the editing genes cutting malaria, 93% with a self -propelled shield

In the last study published in the journal NatureA group of researchers has examined whether protein 1 (FREP1) related to fibrinogen (FREP1) 224 (Q224) renders Anopheles Stephensi Mosquitoes resistant to Plasmodium Infection, quantitatively determined the costs of efficiency associated with this allele and assessed the combined allel drive system to spread this protective variant through populations.

Background

About 600,000 people died of malaria in 2023, mainly children in Sub -Saharan Africa and South Asia. Traditional tools, such as nets treated with insecticide, residual spraying and antimalary drugs, lose soil with resistant to mosquitoes and drug -resistant parasites. Gene technologies that disseminate favorable alleles through the mosquito population, offer a complementary and lasting solution. Komar FREP1 helps parasites cut the middle, and the naturally occurring Q224 seems protective without harming mosquito biology. Testing and safe conducting such endogenous alleles can reduce transmission while maintaining fitness. Further tests are needed to confirm effectivenessFitness, spread and stopping.

About the study

Using regularly interspersed with short palindrome repetitions (CRISPR) and protein 9 associated with CRISPR, the team generated the enemy Anopheles Stephensi Mosquito strains, which differ only at the amino acid 224 FREP1: wild type leucine (WT) (L224) and presumably protective glutamine (Q224). The chairman of the ribonucleic acid (game) directed the intron area of 126 principles (BP) above the codon, enabling the repaired repair (HDR) installation Q224 together with markers of green fluorescent protein (GFP) or fluorescent red protein (RFP). Fitness was assessed on the basis of the wing length, fertility, the indicator of eggs, puppy, rising and longevity of adults in the survival tests of the priest-meier.

Vector competences were measured using a standard membrane feeding with Plasmodium Falciparum (Parasite of human malaria) with low and high gameteocytocia and feeding by mice Plasmodium Berghei (Rodent malaria parasite), which was quantitatively determined by the Oocist and the collapse of the salivary gland. The connected cassette with an allel drive carrying the game L224 was combined with Vasa CAS9 with the inheritance of deviation, and multi -lannel cage tests (10 generations) follow the frequencies of markers. The receiver alleles were genotypped using a polymerase chain reaction (PCR), Sanger sequencing and new generation sequencing (NGS) to estimate the results of repairing the double thread (DSB), including non -hospital ending (NHEJ). Mathematical modeling of Bayesian converters requested, efficiency costs and dynamics as part of laboratory, freely coverage of cage conditions.

Research results

In extensive fitness tests, Allel Frep1Q224 imposed negligible general efficiency costs. The length of the wing, fertility, the hatch of the eggs, the puppies and the appearance of adults were indistinguishable from the control of WT Leucine 224 (FREP1L224), with small, inconsistent differences in the size of the body and the length of the life length of a man who did not change competitive performance in multi-generist cages. Virgin females carrying FREP1Q224 lived as long as controls, and females fed by blood showed a slight reduction in longevity compared to virgins, but slight differences in longevity in men or women powered by blood did not move the frequency of the alleles over time.

Infection experiments have shown strong protection in homozygous mosquitoes. At a low level Plasmodium Falciparum Gametocytemia (0.08%), the dissemination of the infection dropped from about 80% in the controls of Vasa Cas9 and Frep1l224 to about 30% in the mosquitoes of Frep1Q224, while the median Oocist fell from three to zero. Sporozoite loads in the salivary glands have fallen about five times, from medians above 4000 to zero. Even with a higher gametocytia (0.15%), the median numbers of Oocists fell from about 32 to the agent to less than 10, and the disputes were rapidly reduced. Against Plasmodium BergheiThe divergent rodent parasite, Frep1Q224 also reduced the number of middle Oocists (43–25) and the number of disputes (about 19,000 to 11,000). However, the dissemination of the Oocists did not drop significantly, probably due to the unnatural evaporation of mosquitoes and parasites, confirming the refractorhood of a wide spectrum. Resistance required homozygotism: heterozygot (Frep1l224/Frep1Q224) were not significantly protected.

The connected allelic disk was working efficiently. In tests of pair association, the L224 Plus CAS9 ribonucleic acid transformed 50 to 86% of the FREP1L224 alleles to FREP1Q224 via HDR, with a higher conversion, when CAS9 was supplied mathematics, producing the overall frequency of protective alleles up to 93% in the second generation. Non -hospital mutations connecting the final were small (0-12%) and often seemed harmful. In free coverage of population cages vaccinated in the donor alleles 1: 3, the frequency of the protective allele increased from 25 percent to over 90% in 10 generations. A fraction of the NHEJ alleles dropped from 5.4% to less than 0.5%, in accordance with the costs of efficiency associated with the variants of the loss of protein function 1 associated with fibrinogen.

Bayesian modeling confirmed the synthesis of high conversion of the alleles, low indicators of functional resistance alleles and deadly sterile mosaicism, in which WT homozygotes exposed to CAS9-Grna complexes set on the mother suffer mutation Both Frep1 alleles, as factors of the observed super -spatic spread. Finally, mosquitoes downloaded from late generation showed almost completed attenuation Plasmodium Falciparum Oocyst (median zero to 5.5) with low gameteocytemia, confirming that the powered population has become largely resistant to transmission. In particular, the protective allele maintained parity in the competition with the participation of chromosomes, strengthening that its spread reflects the drive, not hidden advantages of efficiency or other ecological costs.

Conclusions

To sum up, this study shows that replacing a single amino acid in FREP1 and the deviation of its inheritance by a combined allelic drive may publish Anopheles Stephensi To a large extent, the parasites of human malaria and rodents, without incurring significant fitness. Because the protective variant retains the normal mosquito biology, it offers a realistic, friendly population path to a lower transmission, complementary nets, residual spraying and anti -paralysis drugs currently threatened with resistance. The same framework can convert resistance alleles into insecticides into sensitivity or implement other protective variants of the host. Ecological, ethical and management strict frames, as well as limiting strategies, will be necessary before any implementation.