2. GMO mosquito that can save the
world from Malaria?
• Researchers have been experimenting with
genetically modifying a variety of insects,
including mosquitoes, fruit flies, moths and
bollworms.
• In an effort to help eradicate dengue fever and
the mosquitoes that spread it, scientist is seeking
approval to release hundreds of thousands of
genetically-modified (GM) mosquitoes designed
to kill off the natural Aedes aegypti variety of the
fly in different countries.
3. TRIVIA
• Mosquitoes don’t cause malaria—the disease
comes courtesy of the Plasmodium falciparum
parasite. Yet mosquitoes do a fine job of
spreading Plasmodium to about half a billion
people every year.
• The parasite depends on mosquitoes for more
than just transport, however. Plasmodium goes
through much of its complex life cycle inside the
mosquito, passing through the gut as it goes.
4. • While mosquitoes may ingest anywhere from 100
to 1,000 immature cells during a blood meal, by
the time the parasite ends up in the mosquito’s
gut, only five or fewer spores, known as oocysts,
remain.
• This is where researchers targeted their attack.
The gut is a complicated place, full of bacteria
that help break down nutrients and digest food.
Perhaps some of these bacteria could be enlisted
to break down the Plasmodium spores as well.
5. • Researchers at the Johns
Hopkins Malaria Research
Institute devised a genetically
modified version of the Pantoes
agglomerans bacteria that
naturally lives in the mosquito
gut. The new P. agglomerans
acts much the same as
ordinary P. agglomerans, and
should be able to spread
through wild mosquito
populations. Except the
engineered bacteria has one
unique and deadly trait: It
produces proteins that destroy
Plasmodium oocysts.
6.
7. • This isn’t the first use of
genetic modification
strategies to quell
mosquito-spread disease.
In November we
reported on a project
that has introduced
genetically modified
mosquitoes into the wild.
The new mosquitoes
carry genes that kill their
young—when they mate
with native mosquito
populations, the
offspring die before they
can fly.
8. • This new approach doesn’t require modifying the
mosquitoes directly, just their gut bacteria, which
makes the technique more portable. More than
100 species of mosquito transmit malaria, and
although the researchers only tested two,
reported that in the Proceedings of the National
Academy of Sciences that the strategy “may well
be ‘universal’ as effectiveness does not appear to
be influenced by mosquito species.” And effective
it was: the genetically enhanced bacteria
suppressed populations of both the human
malaria parasite Plasmodium falciparum and the
rodent malaria parasite Plasmodium berghei by
98 percent.
9. • In Florida Rather than spend $400,000 or more a
year to conduct the aerial sprayings, FKMCD says
it would instead only have to spend $200,000 to
$300,000 a year on the GM mosquitoes.
10. • Created by U.K.-based insect
eradication company Oxitec,
the GM mosquitoes have been
created with an added gene
that, unless they are given the
antibiotic tetracycline, will
automatically kill them. When
they mate with wild
mosquitoes, these GM
mosquitoes also pass on this
gene to the offspring, which is
intended to gradually
decrease the population of
wild mosquitoes over time.
11. • Though the vast majority of
the GM mosquitoes being
released are male, which do
not bite humans, a small
percentage of them are
female. So looking at the
situation just from a human
health perspective, what are
the risks involved with a
human getting bitten by a GM
mosquito? Nobody really
knows, as Oxitec has not
conducted any long-term
research on the safety of GM
mosquitoes interacting with
other creatures or with
humans.