Researchers have eliminated caged mosquitoes using ‘gene drive’ technology to spread a genetic modification that blocks female reproduction.
The team from Imperial College London were able to crash caged populations of the malaria vector mosquito Anopheles gambiae in only 7-11 generations.
This breakthrough shows that gene drive can work, providing hope in the fight against a disease that has plagued mankind for centuries
Professor Andrea Crisanti | Lead researcher
This is the first time experiments have been able to completely block the reproductive capacity of a complex organism in the laboratory using a designer molecular approach.
The technique, called gene drive, was used to selectively target the specific mosquito species An. gambiae that is responsible for malaria transmission in sub-Saharan Africa. There are around 3500 species of mosquito worldwide, of which only 40 related species can carry malaria.
The hope is that mosquitoes carrying a gene drive would be released in the future, spreading female infertility within local malaria-carrying mosquito populations and causing them to collapse.
In 2016, there were around 216 million malaria cases and an estimated 445,000 deaths worldwide, mostly of children under five years old.
Lead researcher Professor Andrea Crisanti, from the Department of Life Sciences at Imperial, said: “2016 marked the first time in over two decades that malaria cases did not fall year-on-year despite huge efforts and resources, suggesting we need more tools in the fight.”
World first: Suppressing a population
The team’s results, published today in Nature Biotechnology, represent the first time gene drive has been able to completely suppress a population, overcoming resistance issues previous approaches have faced.
Professor Crisanti added: “This breakthrough shows that gene drive can work, providing hope in the fight against a disease that has plagued mankind for centuries. There is still more work to be done, both in terms of testing the technology in larger lab-based studies and working with affected countries to assess the feasibility of such an intervention.
“It will still be at least 5-10 years before we consider testing any mosquitoes with gene drive in the wild, but now we have some encouraging proof that we’re on the right path. Gene drive solutions have the potential one day to expedite malaria eradication by overcoming the barriers of logistics in resource-poor countries.”
Targeting ‘doublesex‘: About the research methodology
The team targeted a gene in An. gambiae called ‘doublesex‘, which determines whether an individual mosquito develops as a male or as a female.
The team engineered a gene drive solution designed to selectively alter a region of the doublesex gene that is responsible for female development. Males who carried this modified gene showed no changes, and neither did females with only one copy of the modified gene. However, females with two copies of the modified gene showed both male and female characteristics, failed to bite and did not lay eggs.
Their experiments showed that the gene drive transmitted the genetic modification nearly 100% of the time. After eight generations no females were produced and the populations collapsed because of lack of offspring.
Previous attempts to develop gene drive for population suppression have encountered ‘resistance’, where targeted genes developed mutations that allowed the gene to carry out its function, but that that were resistant to the drive. These changes would then be passed down to the offspring, halting the gene drive in its tracks.
One of the reasons doublesex was picked for the gene drive target was that it was thought not to tolerate any mutations, overcoming this potential source of resistance. Indeed, in the study no functional mutated copy of the doublesex gene arose and spread in the population.
Next steps: Investigating the efficacy
While this is the first time resistance has been overcome, the team say additional experiments are needed to investigate the efficacy and the stability of the gene drive under confined laboratory settings that mimic tropical environments.
This involves testing the technology on larger populations of mosquitoes confined in more realistic settings, where competition for food and other ecological factors may change the fate of the gene drive.
The doublesex gene targeted in the study is similar across the insect world, although different insects have different exact genetic sequences. This suggests the technology could be used in the future to specifically target other disease-carrying insects.
Recent work from Imperial showed that suppressing An. gambiaepopulations in local areas is unlikely to affect the local ecosystem.
The Latest on: Gene drive
via Google News
The Latest on: Gene drive
- Drive Time: Lots of SUVs, pickups — and sometimes a sedanon August 17, 2019 at 7:13 am
Mazda’s I-Activ all-wheel drive adds $3,000 to the base front-drive model ... After 15 years of ownership, my mother, Lenna Wells, and my older brothers, Gene and Armor, sold Dale Wells Ford Garage in ...
- Breast Cancer Gene Mutation Also Increases Risk Of A Type Of Childhood Cancer, Says New Studyon August 16, 2019 at 8:35 am
Responding to the comments, Dr Wang said; "We agree and suggest that additional research ... Further study is needed to translate the gene discovery into clinical practice," said Wang. Hereditary ...
- Scientists reveal how a faulty gene leads to kidney diseaseon August 16, 2019 at 4:05 am
we did not know this protein had this anchoring role in the podocyte until now," explains Dr. Farmer. "TRPC6 is present throughout the body but patients with the faulty gene only develop problems ...
- A linear mixed model approach to gene expression-tumor aneuploidy association studieson August 16, 2019 at 2:06 am
Aneuploidy, defined as abnormal chromosome number or somatic DNA copy number, is a characteristic of many aggressive tumors and is thought to drive tumorigenesis. Gene expression-aneuploidy ...
- Remembering Dr. Ron Reeder, molecular biologist-turned-photographeron August 15, 2019 at 5:56 pm
Dr. Ron Reeder, a Renaissance man who helped unlock the mysteries of gene regulation and then swapped his microscope for a camera, died of lymphoma Aug. 12. He was 79. Reeder joined Fred Hutchinson ...
- Immune-Activating Gene Therapy for Gliobastomaon August 15, 2019 at 3:19 pm
the gene gets shut off again,” explains Chiocca. Drug and vector are both the property of Ziopharm Oncology Inc, which cofunded the trial with the National Institutes of Health. Veledimex had been ...
- Team links gene to children with physical and intellectual disabilitieson August 15, 2019 at 12:08 pm
The results, published today in the American Journal of Human Genetics, suggest that rare variants in the gene DDX6 are associated ... in multiple patients," said Dr. Matt Huentelman, TGen ...
- Gene linked to physical and intellectual disabilities identifiedon August 15, 2019 at 11:55 am
"Something we are quite proud of with this work is our combined effort with other physicians and scientists in Europe to demonstrate that changes in this gene cause this rare syndrome in multiple ...
- Philadelphia gene therapy startup targeting heart disease raises $11Mon August 14, 2019 at 8:53 am
Research conducted by Renovacor founder Dr. Arthur Feldman, a professor of cardiology at Temple ... One of these specific genes is the Bcl2-associated athanogene 3, or BAG3, gene. The prevalence of ...
via Bing News