Genetic modification is the process of altering DNA to create new traits in living organisms. These alterations can be used to improve crops or make animals and plants more resistant to diseases and pests.
Scientists have been modifying the genes of plants, animals, and microbes for thousands of years. These days they can do it much faster with the help of technology.
Golden rice
One of the first successes in genetically modified food was golden rice, which is designed to have a higher level of beta-carotene than traditional varieties. This vitamin is essential for human health and has been shown to be effective in preventing vitamin A deficiency. However, many people still don’t have enough of it, and if not treated, the deficiency can lead to blindness and death.
Scientists inserted two genes into the rice plant genome to create golden rice, including a gene from the daffodil Narcissus pseudonarcissus and another from a common soil bacterium Erwinia uredovora. These genes, when coordinated, cause the rice to produce a high amount of beta-carotene in its endosperm. The final product has been shown to be safe for human consumption, and it could be a key tool in combating vitamin A deficiency worldwide.
This was a very important development in genetically modified foods because it can help fight micronutrient malnutrition, which is the main reason for most deaths from hunger. This project’s success resulted from both good science and public support.
Since the introduction of golden rice, scientists have continued to develop GM crops with more beneficial traits. They have also been able to increase the iron content of bananas. This is a big deal because, in many developing countries, bananas are the staple source of nutrients for their population. This improvement would save lives by reducing the need for vitamin supplements in these countries.
Trees that grow faster
Scientists have genetically modified plants to make them grow faster and stronger so that they can withstand weather extremes and create better wood. These trees also tend to be more resistant to diseases, making them more profitable for farmers. However, many scientists have raised concerns about these genetically modified trees’ potential health and environmental impacts.
Most GE tree research has been done on eucalyptus and pine. The economic driving force behind GE trees is to turn them into industrial plantations for pulp and paper, lumber, and biofuel. Scientists are trying to modify trees for accelerated growth; cold, drought, and insect resistance; enhanced disease and fungus resistance; altered wood quality; and herbicide tolerance.
For example, a San Francisco company has planted 5,000 modified poplars in Georgia that are designed to suck carbon dioxide from the air. These modified trees are able to absorb more carbon dioxide and store it in their roots. The scientists behind this project took a gene from another species of tree and put it into the genetic code of a poplar plant.
The company’s poplars grew more than 50 percent faster than the average over tests lasting about five months. But these results haven’t been tested in a field. And even promising lab results often falter in more realistic field trials, says a researcher working on engineered American chestnuts at the State University of New York College of Environmental Science and Forestry.
Bananas that don’t get diseases
Scientists have been genetically modifying animals for quite some time now. Most famously, scientists cloned the first-ever sheep (called Dolly) in 1996 and created an onion that won’t make you cry in 2008.
Bananas are one of the most important staple crops in the world, and many people eat more than three pounds of them every day. But bananas are vulnerable to a variety of diseases that threaten their production and consumption. Scientists have been trying to solve this problem by genetically introducing new varieties.
The current most popular variety is the Cavendish variety, which is sterile and propagated solely through cloning. It was developed in the 1960s to replace the Gros Michel variety, which had become susceptible to Panama disease and Black Sigatoka. These fungal diseases cut a swath through the industry, reducing yields and quality.
In order to survive the threat of these diseases, the banana industry must begin diversifying its cultivation. This means introducing new varieties that are both tasty and disease resistant. While this will require investment from the industry and supermarkets, it is essential if bananas are to remain a staple food in the world. Genetically modified versions of the Cavendish that are resistant to fungi have already been created. However, these variants are still in the early stages of testing. To reach consumers, they must overcome consumer resistance to GM foods. Scientists have even used gene editing to create a variant of the Cavendish that is resistant to TR4. This approach can be used with other varieties as well.
Glowing cats
Glow-in-the-dark cats might not make it into pet stores, but they can help scientists understand how feline AIDS works. Researchers at the Mayo Clinic in Minnesota inserted a gene from jellyfish and one from rhesus macaques that blocks the feline immunodeficiency virus, or FIV, which causes cat AIDS. FIV wipes out infection-fighting cells in cats, just as HIV does in humans. The GM cats’ coats, claws, whiskers, and noses glow green under blue light, but they look normal in natural light.
In a Nature Methods journal study, the researchers loaded a gene for a fluorescent protein from jellyfish and a monkey gene that inhibits FIV into unfertilized cat eggs called oocytes. The eggs were then fertilized, and all three of the resulting kittens glowed green, indicating they had both the gene for GFP and the anti-FIV gene.
Scientists can now monitor the cats’ immune systems, which they can see working as they watch them grow. They can also use the glowing kitties as a tool to better understand how genes affect the brain since the visual cortex of the cat’s brain is more similar to that of humans than that of mice.
The technique used to create the cats is much easier and more efficient than cloning, which involves replacing a nucleus from an egg cell with the genetic material of another animal. But it’s still not a perfect solution. Cloning, which produced the Dolly sheep, only has about a 5 percent success rate when it comes to domestic animals.
Cows that fart less
Scientists have been tinkering with genes for years to make plants, animals, and even microbes behave differently. They are able to create genetically modified organisms or GMOs. You may have seen these in the food you eat. For example, scientists genetically modified corn to resist bugs that destroy it. Read more about this on our blog.
Targeting cows to fight climate change might seem counterintuitive, but governments from New Zealand to Europe are zeroing in on livestock whose burps and farts contribute about 15% of global greenhouse gas emissions, according to U.N. estimates.
These gases are mostly methane, which is 25 times more potent than carbon dioxide, which is released when fossil fuels burn. A single cow can produce up to 200 kilograms of methane a year. While burning fossil fuels is still the biggest cause of climate change, reducing methane production from cattle farming could have a big impact.
Scientists are working on ways to reduce methane output from cattle by altering their gut bacteria. Since the microbes that control the amount of methane produced by ruminant animals are genetically inherited, selective breeding could eventually lead to cows that produce less of this greenhouse gas.
A British company, Genus Plc, has launched a program to identify “envirocows” with the least-gassy digestive systems. But critics say the firm will push small dairy farmers out of business by making milk more expensive and imposing a ‘cow fart tax’ that would close the price gap with plant-based alternatives.
Pigs that digest phosphorous
Changing the genetic makeup of microorganisms, crops, and animals is a common practice. These modifications allow us to produce desired traits in organisms, such as resistance to disease or increased nutritional value.
While traditional breeding methods can take years, genetic modification allows scientists to make specific changes in DNA. This makes the process much faster and more efficient. In addition, biotechnology has enabled scientists to modify organisms without unwanted traits tagging along.
Pigs are a great example of this. While many people don’t like eating them, pigs are an excellent source of protein. However, pigs cannot digest the phosphorous found in grains. In order to get the nutrient, they must supplement their diets with phytase, an enzyme that breaks down phytic acid and releases phosphate. This enzyme is expensive and can be harmful to the environment, so scientists have been working on a better alternative.
Scientists at the University of Guelph have developed a new line of pigs that can digest phosphorous in their feed on their own. The pigs, known as the Enviropigs, have a gene implanted in their salivary glands that promotes the production of the enzyme. This has allowed the pigs to avoid phosphate supplements and excrete 30 to 65 percent less phosphorous in their feces. Scientists are testing if the Enviropigs can digest other ingredients, such as soybean meal and high-protein distillers dried grain with solubles (DDGS). This could help farmers and feed companies save money while also helping to reduce phosphorus pollution in the environment.
