News / Health

Scientists Use Genetic Technique to Control Malaria Mosquito

Adult mosquitos with glowing eyes that indicate they have been successfully genetically transformed are seen through a fluorescence microscope at the University of Maryland Biotechnology Institute's Insect Transformation Facility in Rockville, Md., June 3
Adult mosquitos with glowing eyes that indicate they have been successfully genetically transformed are seen through a fluorescence microscope at the University of Maryland Biotechnology Institute's Insect Transformation Facility in Rockville, Md., June 3
Jessica Berman

An international team of scientists has developed a way to genetically modify the malaria mosquito so that it would be unable to transmit the disease to humans. Researchers say the method eventually might be used to control large populations of mosquitoes by releasing a small number of modified insects into the wild that could breed the trait into ensuing generations.  

For the past 10 years, researchers have been attempting in the laboratory to biologically alter the malaria mosquito, known as Anopheles gambiae, so it can’t breed and spread the parasitic illness, as well as several other diseases.  

Malaria affects more than 300 million people around the world every year, killing nearly 800,000 people, most of them children.

The goal of the latest research, according to parasitologist Andrea Crisanti of Imperial College London, is to control the female mosquito - which spreads the disease by biting humans - without having to resort to chemical pesticides, which can be harmful to people and the environment.  

“The path that we have chosen is to develop mosquitos that are eventually resistant to malaria and they spread that resistance gene to local populations [of mosquitoes]. So, in principal, they do the job for us,” said Crisanti.

Crisanti led a team of British, U.S. and Japanese researchers that inserted a unique segment of genetic material, or DNA, into the chromosomes of the malaria mosquito.  

The DNA segment, known as a “selfish gene,” produces an enzyme that inactivates specific genes and replaces them with copies of itself.

In laboratory experiments, the researchers mated a small number of male mosquitoes carrying the selfish gene with female insects bred to carry a fluorescence gene that made them glow green for easy identification.

At the start of the experiment, 99 percent of the mosquitoes had the green tag. Just one percent had the selfish gene.

Within a dozen generations, Crisanti said, more than half of the Anopheles mosquitoes lacked the green tag, after acquiring the male mosquitoes’ selfish gene.

“So in this way, generation after generation of the progeny carries the genetic modification and this has increased exponentially. And in a span of 12 generations, which is more or less the time span of the rainy season of a malaria endemic country.”

The results are what are called a proof of principle - scientists have showed it is possible to use genetic engineering to control populations of malaria mosquitoes.

Previous control efforts have involved sterilizing male mosquitoes with radiation and releasing millions of them to mate with females in the wild so they cannot produce fertile offspring. But they have not worked very well. Experts say the female Anopheles prefers to breed with wild male mosquitoes.

Chrisanti said the research team’s goal now is to work on specific Anopholes genes that are essential to its transmission of the malaria parasite.  The team already has identified 10 candidate genes, including an odor-recognition gene that helps mosquitoes locate their human hosts, and a gene that permits the malaria parasite to enter the mosquito’s salivary gland.

An article on genetic manipulation of the Anopheles mosquito for malaria control is published this week in the journal Nature.

You May Like

China Announces Corruption Probe into Senior Ex-Leader

Former security chief and member of Politburo Standing Committee, Zhou Yongkang, being probed for suspected 'serious disciplinary violation' More

India, US Look to Reset Ties During Kerry Visit

This week's talks will be first high level interaction between two countries since Prime Minister Narendra Modi took charge More

Video Young African Leadership Program Renamed to Honor Mandela

YALI program, launched by President Obama in 2010, aims to build skills in business, entrepreneurship, public management and civic leadership More

This forum has been closed.
Comments
     
There are no comments in this forum. Be first and add one

Featured Videos

Your JavaScript is turned off or you have an old version of Adobe's Flash Player. Get the latest Flash player.
Vietnamese Staging Chinese Product Boycott After Oil Rig Spati
X
Reasey Poch
July 28, 2014 7:18 PM
China recently pulled an oil rig from an area of the disputed South China Sea that Vietnam also claims. Despite the action, the incident has had a lingering effect on consumers in Vietnam. VOA's Reasey Poch reports from Hanoi on an effort to boycott Chinese products.
Video

Video Vietnamese Staging Chinese Product Boycott After Oil Rig Spat

China recently pulled an oil rig from an area of the disputed South China Sea that Vietnam also claims. Despite the action, the incident has had a lingering effect on consumers in Vietnam. VOA's Reasey Poch reports from Hanoi on an effort to boycott Chinese products.
Video

Video ESA Spacecraft to Land on a Comet

After a long flight through deep space, a European Space Agency probe is finally approaching its target -- a comet millions of kilometers away from earth. Scientists say the mission may lead to some startling discoveries about the origins of the water on earth. VOA’s George Putic has more.
Video

Video Young Africans Arrive in US for Leadership Program

President Barack Obama's Young African Leadership Initiative has brought hundreds of young Africans to the United States for a six-week program aimed at building their knowledge and skills in fields such as public administration and business. Out of the 50,000 young Africans who applied for the program, just one percent was accepted. VOA's Laurel Bowman caught up with some of those who made the cut and has this report.
Video

Video In Honduras, Amnesty Rumors Fuel US Migration Surges

False rumors in Central America are fueling the current surge of undocumented young people being apprehended at the U.S. border. The inaccurate claims suggest the U.S. will give amnesty to young migrants from the region. As VOA's Brian Padden reports from Honduras, these rumors trace back to President Obama's 2012 executive order to halt deportations for some young undocumented immigrants already living in the United States.
Video

Video Students in Business for Themselves

They're only high school students, but they are making accessories for shoes, fabricating backpacks and doing product photography - all through their own businesses. It's the result of a partnership between a non-profit organization that teaches entrepreneurship and their schools. VOA's Mike O'Sullivan and Deyane Moses met the budding entrepreneurs near Los Angeles.
Video

Video Astronauts Train in Underwater Lab

In the world’s only underwater laboratory, four U.S. astronauts train for a planned visit to an asteroid. The lab - called Aquarius- is located five kilometers off Key Largo, in southern Florida. Living in close quarters and making excursions only into the surrounding ocean, they try to simulate the daily routine of a crew that will someday travel to collect samples of a rock orbiting far away from earth. VOA’s George Putic has more.

AppleAndroid