This is a secondary strategy to
run parallel with the strategy we described some months back in which
populations of genetically modified males are dumped into the environment to
produce a generation of wingless females and more winged males to pass on the
mutation.
The first major field tests are
underway and I am sure we will soon learn about its efficiency,
This item describes an additional
strategy that also acts to preserve the species at the same time in case it is desirable
to do so.
The promise of this approach is
excellent generally and could lead to simple eradication and the outright
elimination of malaria. Malaria is the
present most devastating sickness out there globally and lacks effective counter
measures that are bullet proof, unlike AIDS which at least be pushed into the
background while the victim gets on with his life.
Genetically-engineered
mosquitoes can't transmit malaria
By Ben
Coxworth
15:48 June 13, 2012
Last year, Prof. Anthony James announced that he and his colleagues had
genetically
altered Aedes aegypti mosquitoes in a fashion that could
drastically reduce their populations. In a nutshell, the altered genes cause
the female mosquitoes to be born without wings – this makes it rather difficult
for them to go foraging for blood, and turns them into easy prey for almost any
predator. The non-biting males are born with wings, and subsequently
go off and mate with unmodified females, passing the modified genes along
to their offspring. Now, James has done some more genetic engineering, to
create mosquitoes that can’t spread malaria.
The University of California , Irvine molecular biologist worked with colleagues from
both UC Irvine, and the Pasteur Institute in Paris
They started with mice that were infected with the Plasmodium
falciparum parasite, which causes malaria. Those mice created antibodies
in order to kill the parasites. The scientists identified the molecular
components of this immune response, then altered the genes of
the Anopheles stephensi mosquito in order to cause the same response
to occur in their bodies – ordinarily, mosquitoes simply act as carriers of the
parasites, exhibiting no immune response towards them.
In short, parasites picked up by the mosquitoes are killed by the
insects’ altered immune systems, meaning that people subsequently bitten by
those mosquitoes won’t develop malaria. Although the study was done
using Anopheles stephensi, the technique could reportedly be used on
dozens of different types of mosquitoes.
Unlike James’ previous efforts involving the flightless females, this
approach would not actually reduce the numbers of mosquitoes present in an
area. Much as many people might like the idea of the eradication of
mosquitoes, this could be a good thing – it’s still unclear how the sudden
elimination of a species as plentiful as the mosquito might affect ecosystems.
That said, of course, the wisdom of releasing genetically modified mosquitoes
to breed with wild populations might also be questioned.
Given that approximately one million people die worldwide every year
from malaria – which is spread mostly by mosquitoes – it’s a risk that some
people may be willing to take. “We see a complete deletion of the infectious
version of the malaria parasite,” said James. “This blocking process within the
insect that carries malaria can help significantly reduce human sickness and
death.”
A paper on his research was published this week in the
journal Proceedings
of the National Academy of Sciences.
Source: University of
California, Irvine
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