Gene drive causes collapse in captive mosquito population

  Last updated September 27, 2018 at 10:46 am


Technique targets the development of females.

The Anopheles Mosquito. Credit: Getty Images

A CRISPR-based gene drive has caused the collapse of a population of caged malaria-carrying mosquitoes, UK researchers report.

The study, published today in Nature Biotechnology, targeted a gene that determines whether an individual mosquito develops as a male or a female. 

Previous attempts have been thwarted by the mosquitoes developing resistance to the gene drive, but the researchers say this didn’t happen and within eight generations no females were being produced and the population collapsed.

The gene drive used a new mutation construct designed specifically to target the gene responsible for determining the sex of an individual mosquito, dubbed the doublesex gene. 

The mutation affects the development of female mosquitoes, rendering them harmless and significantly lowering the number of unaffected eggs laid, but does not affect the non-biting male mosquitoes. 

Prior research had using CRISPR technology had not proven successful until the introduction of the doublesex gene. 

Gordana Rasic, senior research officer in the Mosquito Control Group (QMIR Berghofer Medical Research Institute), explained the process.

“By linking the mutation to a CRISPR-based machinery that ensures it is transmitted nearly 100 per cent of the time, the mutation quickly spreads through a population, turning more and more females into intersex mosquitoes that can’t bite and reproduce.

“The heavy hit on egg production was enough to cause total collapse of experimental caged populations in less than a year,” says Rasic.

Dr Cameron Webb, Clinical Lecturer with the University of Sydney, believes that this new research has the potential to not only be implemented in combating malarial mosquitoes, but the less severe mosquito issue found here in Australia.

“This latest research demonstrates great potential for future management of malaria in many parts of the world, especially Africa,” says Dr Webb.

“However, adapting this approach to Australian mosquito-borne disease may face many challenges. Australia is free of malaria, but thousands of people fall ill following mosquito bites each summer.”

The release of genetically modified mosquitoes is still a long way off but perhaps in the future it will be an additional tool available to local health authorities in reducing the public health risks associated with our local mosquitoes.”

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Gene drive causes collapse in captive mosquito population

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