By Ben
Coxworth
May 13, 2020
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A female Anopheles gambiae
mosquito, packin' a blood meal and two X chromosomes CDC/ James Gathany
VIEW 1 IMAGES
Led by Prof. Andrea Cristani of
Imperial College London, an international research team
started with a caged population of Anopheles gambiae mosquitoes – this is the
mosquito group that's chiefly responsible for the transmission of malaria in
sub-Saharan Africa.
The scientists then created a
genetically-manipulated version of the males, in which a DNA-cutting enzyme
destroyed the X chromosome during the production of sperm. When those males
mated with conventional females, the offspring were predominantly male – this is
because while just one X and a Y chromosome trigger the development of males,
two X's are required for females.
Ordinarily, the X-destroying gene
would only be passed on to about 50 percent of the offspring. Utilizing what's
known as gene
drive technology, however, the researchers were able to boost that figure to
almost 100 percent. As a result, over just a few generations, the caged
population of mosquitoes became entirely male – it was thus unsustainable, and
collapsed as a result.
It is hoped that once more
studies have been conducted, the genetically-manipulated males could be released
into wild Anopheles gambiae populations, ultimately eliminating them in specific
geographical regions. And even before those populations collapsed completely,
the malaria problem would already be addressed, as it's only the female
mosquitoes that bite.
"This study represents a key
milestone in the long-sought objective to bias the progeny of the human malaria
mosquito so that only non-biting males are produced," says Cristani. "Having a
proven driving sex-distorter opens a new avenue for scientists to develop
genetic vector controls of malaria with the aim of eradicating the disease."
A paper on the research was
recently published in the journal Nature
Biotechnology.
Source: Imperial
College London