News / Science & Technology

    Genetically-Modified Rainbow Trout Could Boost Aquaculture

    Comparing a standard grown rainbow trout (left) and a genetically-modified rainbow trout (right). Both fish are the same age.
    Comparing a standard grown rainbow trout (left) and a genetically-modified rainbow trout (right). Both fish are the same age.

    For many years millions of people around the world have been fed by genetically-modified crops.  Soon, some food animals will be genetically-modified as well, to be larger and grow more efficiently to feed a rapidly growing population.  
    At a laboratory in Rhode Island, rainbow trout much larger than usual are already being produced.

    The two rainbow trout (pictured above) are the same age and were raised in the same tank.  But the larger one has been genetically modified. 

    "You can see this enhanced muscling and these are the parent stock,"  Professor Terry Bradley explained. Bradley leads the research at [the Department of fisheries and veterinary science at] the University of Rhode Island. "The other fish on the bottom, you can see it doesn't have the increased muscle mass.  So we know this fish has about 20 percent more muscle mass than the standard fish has."

    The process starts in a laboratory.  Over the last four years, Dr. Bradley has injected 20,000 rainbow trout eggs with a DNA variation which inhibits a protein that restricts muscle growth.

    "Each egg and the micro pump is set to deliver 5 nano-liters of DNA which you cannot see it.  We put dye in it, so all you see is this tiny little dot inside the egg, of green food coloring, and that's the only way you know it has been injected," he said.

    In a normal-sized trout, a genetically-controlled protein called "Myostatin" keeps the fish from growing beyond a certain size.

    Dr. Bradley's research shows that altering the gene that produces Myostatin seems to result in more muscle mass

    "We inject them into the egg, so each egg gets injected with a little bit of DNA," he says, "and if you get lucky a bit of that gets incorporated into the genome of the developing embryo and that develops into a fish."

    Once the eggs hatch they start their journey through a series of tanks in this aquaculture research facility.  But from all the thousands of injected eggs, only 300 fish so far have carried the modified gene.

    The research will continue for a few more years before a larger and more efficiently-growing rainbow trout can move on to the commercial markets.  Bradley says the final goal is to increase the overall efficiency of aquaculture.

    "For example where it typically may take 1.2 kilogram of feed to produce one kilogram of fish we hope that by inhibiting Myostatin we hope that one kilogram of food will produce one kilogram of fish," Bradley said.

    Professor Bradley's study has been funded by the U.S. Department of Agriculture.  

    "The purpose of understanding muscle growth would be, first, to produce that muscle in a more efficient and more sustainable manner, that is to produce more meet for consumption with less input of resources, less energy, less feed, less labor input," stated Mark Mirando, who is with the Department's National Institute of Food and Agriculture. 

    And perhaps, he says, with better taste or more nutrients. Worldwide, the fish most commonly produced through aquaculture are catfish and tilapia, both freshwater species.  But salmonid species like salmon and trout are rapidly becoming more popular in the industry.

    The U.S. Department of Agriculture says the value of aquaculture production rose to nearly $1 billion in the U.S.over the past 20 years, mostly due to growing demand for fish in general and harvesting restrictions on wild fish.
    Mirando says the rapid growth of aquaculture is linked to population growth.

    "The demand for seafood in the U.S. and worldwide is rapidly increasing but the ability of the oceans to supply that food, even at the current levels, disregarding population increases and increases in demand; the ability of the oceans to supply that is diminishing," Mirando said.

    Mirando dismisses concerns about genetic modifications, pointing out that humans have already genetically modified many plants and animals through centuries of selective breeding.  The most common examples, he says, are dogs, which range in size from Chihuahuas to great Danes.

    Comparing a standard grown rainbow trout (left) and a genetically-modified rainbow trout (right). Both fish are the same age.

    You May Like

    Clinton, Trump and the 'Woman’s Card'

    Ask supporters of Democratic front-runner in US presidential campaign, and they’ll tell you Republican presidential candidate is playing a dangerous hand

    Russian Censorship Group Seeks Chinese Help to Better Control Internet

    At recent Safe Internet League forum in Moscow, speakers from both nations underscored desire for authorities to further limit and control information online

    Video Makeshift Pakistani School Helps Slum Kids

    Free classes in Islamabad park serve a few of the country’s nearly 25 million out-of-school youths; NGO cites ‘education crisis’

    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.
    Turkish Kurd Islamist Rally Stokes Tensionsi
    X
    April 29, 2016 12:28 AM
    In a sign of the rising power of Islamists in Turkey, more than 100,000 people recently gathered in Diyarbakir, the main city in Turkey’s predominantly Kurdish southeast, to mark the birthday of the Prophet Muhammad. The gathering highlighted tensions with the pro-secular Kurdish nationalist movement. Dorian Jones reports from Diyarbakir.
    Video

    Video Turkish Kurd Islamist Rally Stokes Tensions

    In a sign of the rising power of Islamists in Turkey, more than 100,000 people recently gathered in Diyarbakir, the main city in Turkey’s predominantly Kurdish southeast, to mark the birthday of the Prophet Muhammad. The gathering highlighted tensions with the pro-secular Kurdish nationalist movement. Dorian Jones reports from Diyarbakir.
    Video

    Video Pakistani School Helps Slum Kids

    Master Mohammad Ayub runs a makeshift school in a public park in Islamabad. Thousands of poor children have benefited from his services over the years, but, as VOA's Ayesha Tanzeem reports, roughly 25 million school-age youths don't get an education in Pakistan.
    Video

    Video Florida’s Weeki Wachee ‘Mermaids’ Make a Splash

    Since 1947, ‘mermaids’ have fascinated tourists at central Florida’s Weeki Wachee Springs State Park with their fluid movements and synchronized ballet. Performing underwater has its challenges, including cold temperatures and a steady current, as VOA’s Lin Yang and Joseph Mok report.
    Video

    Video Somali, African Union Forces Face Resurgent Al-Shabab

    The Islamic State terror group claimed its first attack in Somalia earlier this week, though the claim has not been verified by forces on the ground. Meanwhile, al-Shabab militants have stepped up their attacks as Somalia prepares for elections later this year. Henry Ridgwell reports there are growing frustrations among Somalia’s Western backers over the country’s slow progress in forming its own armed forces to establish security after 25 years of chaos.
    Video

    Video Bangladesh Targeted Killings Spark Wave of Fear

    People in Bangladesh’s capital are expressing deep concern over the brutal attacks that have killed secular blogger, and most recently a gay rights activist and an employee of the U.S. embassy. Xulhaz Mannan, an embassy protocol officer and the editor of the country’s only gay and transgender magazine Roopban; and his friend Mehboob Rabbi Tanoy, a gay rights activist, were hacked to death by five attackers in Mannan’s Dhaka home earlier this month.
    Video

    Video Documentary Tells Tale of Chernobyl Returnees

    Ukraine this week is marking the 30th anniversary of the world's worst nuclear accident, at the Chernobyl nuclear power plant. Soviet officials at first said little about the accident, but later evacuated a 2,600-square-kilometer "exclusion zone." Some people, though, came back. American directors Holly Morris and Anne Bogart created a documentary about this faithful and brave community. VOA's Tetiana Kharchenko reports from New York on "The Babushkas of Chernobyl." Carol Pearson narrates.
    Video

    Video Nigerians Feel Bite of Buhari Economic Policy

    Despite the global drop in the price of oil, Nigerian President Muhammadu Buhari has refused to allow the country's currency to devalue, leading to a shortage of foreign exchange. Chris Stein reports from Lagos businessmen and consumers are feeling the impact as the country deals with a severe fuel shortage.
    Video

    Video  Return to the Wild

    There’s a growing trend in the United States to let old or underused golf courses revert back to nature. But as Erika Celeste reports from one parcel in Grafton, Ohio, converting 39 hectares of land back to green space is a lot more complicated than just not mowing the fairway.
    Video

    Video West Urges Unity in Libya as Migrant Numbers Soar

    The Italian government says a NATO-led mission aimed at stemming the flow of migrants from Libya to Europe could be up and running by July. There are concerns that the number of migrants could soar as the route through Greece and the Balkans remains blocked. Western powers say the political chaos in Libya is being exploited by people smugglers — and they are pressuring rival groups to come together under the new unity government. VOA's Henry Ridgwell reports.
    Video

    Video Russia’s TV Rain Swims Against Tide in Sea of Kremlin Propaganda

    Russia’s media freedoms have been gradually eroded under President Vladimir Putin as his government has increased state ownership, influence, and restrictions on critical reporting. Television, where most Russians get their news, has been the main target and is now almost completely state controlled. But in the Russian capital, TV Rain stands out as an island in a sea of Kremlin propaganda.

    Special Report

    Adrift The Invisible African Diaspora