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

    Video As Refugees Perish, Greek Graveyards Fill

    Before burial at overflowing cemeteries, unidentified dead being swapped for DNA, in case some day relatives come to learn their fate

    Russian Opposition Leader Sues Putin for Conflict of Interest

    Alexei Navalny tells VOA in exclusive interview why transfer of $2 billion from country’s wealth fund to company with ties to President Putin’s son-in-law triggered lawsuit

    How Diversity Has Changed America

    Over the past four decades, the level of diversity in the United States has increased most in these four states

    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.
    As Refugees Perish, Greek Graveyards Filli
    X
    Hamada Elsaram
    February 11, 2016 8:01 PM
    Aid workers on the Greek island of Lesbos say they are struggling to bury the increasing number of bodies of refugees that have been recovered or washed up ashore in recent months.  The graveyards are all full, they say, yet as tens of thousands of people clamor to get out of Syria, it is clear refugees will still be coming in record numbers. For VOA, Hamada Elrasam reports from Lesbos, Greece.
    Video

    Video As Refugees Perish, Greek Graveyards Fill

    Aid workers on the Greek island of Lesbos say they are struggling to bury the increasing number of bodies of refugees that have been recovered or washed up ashore in recent months.  The graveyards are all full, they say, yet as tens of thousands of people clamor to get out of Syria, it is clear refugees will still be coming in record numbers. For VOA, Hamada Elrasam reports from Lesbos, Greece.
    Video

    Video To Fight Zika, Scientists Target Mosquitoes

    Mosquitoes strike again. The Zika virus outbreak is just the latest headline-grabbing epidemic carried by these biting pests, but researchers are fighting back with new ways to control them. VOA's Steve Baragona takes a look.
    Video

    Video Mosul Refugees Talk About Life Under IS

    A top U.S. intelligence official told Congress this week that a planned Iraqi-led operation to re-take the city of Mosul from Islamic State militants is unlikely to take place this year. IS took over the city in June 2014, and for the past year and a half, Mosul residents have been held captive under its rule. VOA's Zana Omar talked to some families who managed to escape. Bronwyn Benito narrates his report.
    Video

    Video Scientists Make Progress Toward Better Diabetes Treatment, Cure

    Scientists at two of the top U.S. universities say they have made significant advances in their quest to find a more efficient treatment for diabetes and eventually a cure. According to the International Diabetes Federation, the disease affects more than 370 million people worldwide. VOA’s George Putic reports.
    Video

    Video NATO to Target Migrant Smugglers

    NATO has announced plans to send warships to the Aegean Sea to target migrant smugglers in the alliance's most direct intervention so far since a wave of people began trying to reach European shores.
    Video

    Video Russia's Catholics, Orthodox Hopeful on Historic Pope-Patriarch Meeting

    Russia's Catholic minority has welcomed an historic first meeting Friday in Cuba between the Pope and the Patriarch of Russia's dominant Orthodox Church. The Orthodox Church split with Rome in 1054 and analysts say politics, both church and state, have been driving the relationship in the centuries since. VOA's Daniel Schearf reports from Moscow.
    Video

    Video Used Books Get a New Life on the Streets of Lagos

    Used booksellers are importing books from abroad and selling them on the streets of Africa's largest city. What‘s popular with readers may surprise you. Chris Stein reports from Lagos.
    Video

    Video After NH Primaries All Eyes on South Carolina

    After Tuesday's primary in New Hampshire, US presidential candidates swiftly turned to the next election coming up in South Carolina. The so-called “first-in-the-South” poll may help further narrow down the field of candidates. Zlatica Hoke reports.
    Video

    Video US Co-ed Selective Service Plan Stirs Controversy

    Young women may soon be required to register with the U.S. Selective Service System, the U.S. government agency charged with implementing a draft in a national emergency. Top Army and Marine Corps commanders told the Senate Armed Services Committee recently that women should register, and a bill has been introduced in Congress requiring eligible women to sign up for the military draft. The issue is stirring some controversy, as VOA’s Bernard Shusman reports from New York.
    Video

    Video Lessons Learned From Ebola Might Help Fight Zika

    Now that the Ebola epidemic has ended in West Africa, Zika has the world's focus. And, as Carol Pearson reports, health experts and governments are applying some of the lessons learned during the Ebola crisis in Africa to fight the Zika virus in Latin America and the Caribbean.
    Video

    Video Smartphone Helps Grow Vegetables

    One day, you may be using your smartphone to grow your vegetables. A Taipei-based company has developed a farm cube — a small, enclosed ecosystem designed to grow plants indoors. The environment inside is automatically adjusted by the cube, but it can also be controlled through an app. VOA's Deborah Block has more on the gardening system.
    Video

    Video Illinois Voters Have Mixed Emotions on Obama’s Return to Springfield

    On the ninth anniversary of the launch of his quest for national office, President Barack Obama returned to Springfield, Illinois, to speak to the Illinois General Assembly, where he once served as state senator. His visit was met with mixed emotions by those with a front-row seat on his journey to the White House. VOA's Kane Farabaugh reports.
    Video

    Video Exhibit Turns da Vinci’s Drawings Into Real Objects

    In addition to being a successful artist, Renaissance genius Leonardo da Vinci designed many practical machines, some of which are still in use today, although in different forms. But a number of his projects were never realized — until today. VOA’s George Putic reports.
    Video

    Video Heated Immigration Debate Limits Britain’s Refugee Response

    Compared to many other European states, Britain has agreed to accept a relatively small number of Syrian refugees. Just over a thousand have arrived so far -- and some are being resettled in remote corners of the country. Henry Ridgwell reports on why Britain’s response has lagged behind its neighbors.
    Video

    Video Russia's Car Sales Shrink Overall, But Luxury and Economy Models See Growth

    Car sales in Russia dropped by more than a third in 2015 because of the country's economic woes. But, at the extreme ends of the car market, luxury vehicles and some economy brands are actually experiencing growth. VOA's Daniel Schearf reports from Moscow.