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Mosquitoes are responsible for spreading a number of human diseases (including malaria, Dengue fever, and Zika virus), and account for nearly half a million deaths per year worldwide. For many years, scientists have been investigating technologies that could help control or even eliminate mosquito populations, and CRISPR-Cas9 technology offers a potentially powerful approach to eliminate mosquitos: gene drives.
Genes normally have a 50-50 chance of being passed from parents to children, but gene drives are genetic elements designed to be passed from parents to children at a near 100% rate. This enables a gene drive (and the other genes that it carries) to very rapidly spread throughout an interbreding population, essentially giving scientists the ability to genetically modify all individuals in that population. See this physics forum thread from a few years ago on the subject: https://www.physicsforums.com/threads/gene-drives-how-to-genetically-modify-an-ecosystem.762289/
Now, scientists provided the first demonstration that, in a controlled laboratory setting, gene drive technology could be used to eradicate a population of mosquitoes:
Here's the associated paper:
Kyrou et al. A CRISPR–Cas9 gene drive targeting doublesex causes complete population suppression in caged Anopheles gambiae mosquitoes. Nat Biotech. Published online 24 Sep 1028
So, it appears we may be at the cusp of having the technology to completely eradicate mosquitoes. The question is: should we?
Genes normally have a 50-50 chance of being passed from parents to children, but gene drives are genetic elements designed to be passed from parents to children at a near 100% rate. This enables a gene drive (and the other genes that it carries) to very rapidly spread throughout an interbreding population, essentially giving scientists the ability to genetically modify all individuals in that population. See this physics forum thread from a few years ago on the subject: https://www.physicsforums.com/threads/gene-drives-how-to-genetically-modify-an-ecosystem.762289/
Now, scientists provided the first demonstration that, in a controlled laboratory setting, gene drive technology could be used to eradicate a population of mosquitoes:
https://www.npr.org/sections/goatsa...odified-to-crash-species-that-spreads-malariaFor the first time, scientists have demonstrated that a controversial new kind of genetic engineering can rapidly spread a self-destructive genetic modification through a complex species.
The scientists used the revolutionary gene-editing tool known as https://www.broadinstitute.org/what-broad/areas-focus/project-spotlight/questions-and-answers-about-CRISPR to engineer mosquitoes with a "https://wyss.harvard.edu/staticfiles/newsroom/pressreleases/Gene%20drives%20FAQ%20FINAL.pdf which rapidly transmitted a sterilizing mutation through other members of the mosquito's species.
After mosquitoes carrying the mutation were released into cages filled with unmodified mosquitoes in a high-security basement laboratory in London, virtually all of the insects were wiped out, according to a report in Nature Biotechnology.
Here's the associated paper:
Kyrou et al. A CRISPR–Cas9 gene drive targeting doublesex causes complete population suppression in caged Anopheles gambiae mosquitoes. Nat Biotech. Published online 24 Sep 1028
https://www.nature.com/articles/nbt.4245Abstract:
In the human malaria vector Anopheles gambiae, the gene doublesex(Agdsx) encodes two alternatively spliced transcripts, dsx-female(AgdsxF) and dsx-male (AgdsxM), that control differentiation of the two sexes. The female transcript, unlike the male, contains an exon (exon 5) whose sequence is highly conserved in all Anopheles mosquitoes so far analyzed. We found that CRISPR–Cas9-targeted disruption of the intron 4–exon 5 boundary aimed at blocking the formation of functional AgdsxF did not affect male development or fertility, whereas females homozygous for the disrupted allele showed an intersex phenotype and complete sterility. A CRISPR–Cas9 gene drive construct targeting this same sequence spread rapidly in caged mosquitoes, reaching 100% prevalence within 7–11 generations while progressively reducing egg production to the point of total population collapse. Owing to functional constraint of the target sequence, no selection of alleles resistant to the gene drive occurred in these laboratory experiments. Cas9-resistant variants arose in each generation at the target site but did not block the spread of the drive.
So, it appears we may be at the cusp of having the technology to completely eradicate mosquitoes. The question is: should we?
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