Scientists think they have figured out a way to
wipe out mosquitoes that transmit malaria, a
horrible disease that kills a million humans every
year.
Based on laboratory experiments, they think they
can do it by messing up the sex life of Anopheles
gambiae, the mosquito that sucks blood out of
other animals, including humans, that carries the
parasite that causes a disease for which there is
no vaccine.
It has been estimated that a child dies every 30
seconds in sub-Sahara Africa from malaria, so if
the lab results also work in the real world then this
could be the turning point in an effort that has
frustrated medical researchers for many decades.
That's a big "if," but scientists at Imperial College
London, who have spent years working on this
problem, think they are finally on the right track.
Their "breakthrough," as other scientists have
called it, works by genetically engineering
mosquitoes to produce offspring that are
exclusively male at least 95 percent of the time.
With fewer and fewer females in each succeeding
generation, the technique wiped out the entire
population of caged wild mosquitoes within six
generations, according to a study published in
Nature Communications.
The scientists transferred a gene from slime mold
that produces an enzyme that chops up DNA when
it finds a specific sequence. In this case it latched
on to a section of the x chromosome which
determines gender during the period when the
male mosquito was producing sperm. Thus nearly
all the offspring were males.
"We think our innovative approach is a huge step
forward," lead researcher Andrea Crisanti said in
releasing the report. "For the very first time, we
have been able to inhibit the production of female
offspring in the laboratory and this provides a new
means to eliminate the disease."
The technique could pay off immediately in that
only females bite humans, because they need the
nutrients in blood to produce healthy eggs, so
fewer females would mean fewer bites.
That sounds like good news for the entire world,
since mosquito bites are irritating and dangerous.
Mosquitoes transmit several diseases, not just
malaria, including West Nile Virus and yellow fever,
which devastated New Orleans in 1905.
Unfortunately, even if this works in the wild, it will
work only on Anopheles gambiae, one of at least
3,000 species of this nasty insect, so don't throw
away your DEET yet. But it could point the way to
other genetic avenues that would work with other
species.
However, this would be a new chapter, and
perhaps a dangerous one, in the ongoing human
effort to change the natural world through genetic
engineering to solve a problem that is faced by
one species, ourselves. And it is possible that
once experiments begin in the wild, an entire
species could be wiped out through genetic
engineering, a threat that troubles many critics.
On the surface, this would appear to be a slam
dunk. Why would anyone object to sacrificing
mosquitoes to save the lives of millions of
children?
The mosquito has been described as the deadliest
animal on the entire planet, and it's safe to say
that nearly all humans detest these little beasts,
but wiping out an entire species is something that
should require a lot of thought and discussion.
Even if the victim is a just a mosquito. Everyone
hates mosquitoes. The female attacks with a
vengeance, drawing blood and leaving a blister-
like wound.
But is it worth it to wipe out an entire species of
another living creature just to serve the needs of a
single species, ourselves? My guess is nearly
everyone would answer that in the affirmative, but
this is a bridge that doesn't lead to nowhere.
We've never experimented on that scale before,
and if this works it will surely lead to wider genetic
engineering in the animal world.
Even Crisanti described this as a "quantum leap in
terms of what has been done before."
Yet even though the stakes here are high, it's hard
not to get excited about this potential
breakthrough.
The only other progress in fighting malaria has
involved hanging insecticide-treated nets over the
beds of children and pregnant women, and that
has reduced malaria by an estimated 50 percent.
Drying out muddy ponds where mosquitoes lay
their eggs also has helped. But that still leaves a
lot of room for human suffering, and the nets only
last for a few years.
The mosquito is not likely to easily give up its
preference for human blood. As anyone who lives
in a damp area knows, it can smell human breath
75 feet away and travel a couple of miles per day,
beating its wings 300 to 600 times per second. It
seems ideally equipped to torment humans.
And it is equally successful at developing
immunity from the scores of insecticides that have
been produced over the years.
That raises another question. If it has been so
successful in the past, can it out-engineer the
engineers and defeat human efforts to mess up its
sex life? (Scientists call it a "sex ratio distortion
system.")
Maybe. We won't know for at least two years when
this project is expected to move from the lab to
the real world.
FROM AROUND THE WEB
30 Photos That Explain Why Kanye West Married
Kim Kardashian [Photos] (HipHopWired)
Famous Couples Who Are Never Getting Married
(Madame Noire)
Things We All Worry About The First Time
(Madame Noire)
Gay Celebs Who Tend To Play Straight Roles
(Madame Noire)
RELATED ARTICLES
TECHNOLOGY VIDEO
Getty Images
PREV
No comments:
Post a Comment