Should we go with GMOs?

Discussion about GMOs (genetically modified organisms) in our food supply is everywhere in the news. Some people support the idea that I am the only genetically modified animal GMOs can provide better currently sold as a pet. quality food to more people worldwide. Other people GloFish® are genetically modified fear that GMOs will seriously fish. The original idea was to create damage human health and fish that could detect pollution the environment. by fluorescing (glowing) in the presence of certain toxicants. The So what are GMOs? fish sold as pets don’t do this. They GMOs are plants, animals, simply glow using the same gene as and microbes whose DNA has been changed through genetic engineering found in jellyfish. techniques. Scientists insert genes from one organism into another or turn off existing genes. Mice are genetically engineered to be models for biomedical studies. Bacteria are engineered to produce medications such as insulin or enzymes used in cheese production.

Some genetically modified plants are used as crops to feed humans and animals. GMO crops, especially corn and soybeans, are widely grown in the United States. GMOs for food use in other countries varies. So far, one genetically altered animal, the AquAdvantage salmon, has been approved Scientists by the US Food and Drug Administration as human food. have been creating GMOs since What are GMO foods good for? the 1980’s. Scientists develop genetically engineered crops to improve the organisms we depend on for food by making them grow faster, thrive under different climate conditions, resist herbicides and insect pests, have better flavor, or be more nutritious. Here are some examples of foods currently sold in the United States. Other products are in development in the US and wordwide. Bt corn and soybeans are Roundup Ready soybeans Ringspot virus resistant papyas resistant to certain insects without and corn allow farmers to apply grow even where the virus is present in soil. the need for pesticides. Bt corn and the herbicide glyphosate (brand Hawaiian farmers started growing these soybeans were engineered by inserting name Roundup) to kill weeds papayas in 1998. Virus resistant papayas were genes from Bacillus thuringiensis (Bt), a without harming the soybean or engineered by inserting genes that make virus bacterium that occurs naturally in soil and corn plants. Roundup Ready crops proteins. These genes trigger a plant response produces proteins that kill specific insects. were engineered by inserting against the virus and stops its effects. a gene that makes an enzyme AquAdvantage salmon grow at that’s not affected by glyphosate. Arctic Apples do not get brown after about twice the normal rate. So, they can The gene for this enzyme was they are cut open like other apples do. Arctic be sold for food more quickly. AquAdvantage found in a soil bacterium called Agrobacterium apples are engineered by inserting a DNA salmon were engineered by changing a gene tumefaciens. 1 sequence to turn off the genes that produce an that controls a growth hormone. enzyme called polyphenol oxidase (PPO). PPO is required for browning. How are GMOs made? Whether genetic engineering is used for biomedical studies, Yes, you are producing medicines, or food, GMOs are created using the same basic eating GMOs steps: identify a trait of interest, isolate the genes for the trait, insert that trait into desired organism, and grow the engineered organism. If you live in the USA, and if The technology is always advancing, but the methods shown here are you do not exclusively eat commonly used. organic foods (which don’t contain GMOs), you are eating genetically modified foods in some form. When genes inserted into a plant come from a different kind As of 2014, the USDA of plant or another organism, reports the percent of the resulting GMO is called GMO crops grown “transgenic.” Sometimes, like in the USA as: in the Arctic Apple, the inserted Soybeans – 94% GMO gene comes from the same kind Corn – 93% GMO of plant. This type of GMO is not transgenic. Cotton – 96% GMO Sugar Beets – 90% GMO

Agrobacterium tumefaciens bacteria naturally invade plant cells and insert their own DNA. This behavior is exploited as a tool for genetic engineering.

Should we go with GMOs? 2 GMO graphic adapted from Science in the News, Harvard University. “GMOs” before Genetic Engineering We’ve seen that GMOs are defined as organisms whose DNA has been altered with genetic engineering techniques. This Selective breeding is a low- technology has only been around for a few decades. tech way to modify genes But humans have been altering the DNA of organisms for many thousands of years. Let’s find out how that’s possible! Do you have a dog as a pet? Even if your grey wolf dog is a breed like a Husky that looks similar to a wolf, you can easily tell that dogs and wolves are quite different. Your dog loves to play and cuddle with you. Wolves are secretive animals who don’t like being close to humans. Genetic studies show that wolves are the ancestors of dogs. So how did wolves and dogs become so different?

The answer is something called selective breeding. As many as 30,000 years ago, wolves that were more tolerant of humans began hanging around, perhaps following human groups for food scraps. These friendlier wolves Selective breeding has produced were selected by humans to breed together, producing even friendlier pups. a rainbow of carrots. Many, many generations later, humans had the animals we now know as dogs to be companions and do jobs such as protecting us and helping us hunt.

Calling dogs a sort of “GMO” (genetically modified organism) wouldn’t really be wrong. People didn’t modify wolves’ genes in a laboratory, but their genes were changed by our actions. Dog genes and wolf genes are no longer the same. • People picked animals with desireable traits and bred them together. Desireable genes that started out being rare in the wolf population became more and more common in dogs. • Through mutations, dogs gained new genes that never appeared in wolves. If a mutation produced a desirable trait, people bred dogs with that trait to each other, and the new gene became established in dogs. The ancestor of modern corn, • Fast forward to today, and we have everything from teosinte, is on the left. Selective 5-pound Chihuahuas to 150-pound Mastifs. breeding has resulted in modern corn. (Photo courtesy of John Doebley.)

And on to corn… In the same way, people have changed the genes of plants for their benefit. For example, we enjoy biting into a plump, juicy ear of corn. Developed by But the ancestor of corn, teosinte, has a tiny stalk of kernels, each sealed inside a hard shell. About 10,000 years ago, ancient farmers (in what is now Mexico) noticed that some plants had bigger cobs and softer kernels. By breeding those desireable plants together, more of the resulting crop would have those traits, and maybe even better Good nutrition to battle environmental toxicants. ones. Many, many generations of breeding have resulted in the corn we know today. through funding from

Should we go with GMOs? 3 Grant number R25 OD011090 What worries people about GMOs? According to the Untangling the web of news stories about GMOs Pew Research is not easy! Google “GMO” you will see everthing Center, 57% of from “10 Reasons to Avoid GMOs” to “GMOs May Feed Americans think the World Using Fewer Pesticides.” Before going “pro” March Against GMOs are unsafe or “con,” consider the source of the article and the Monsanto is a social to eat. 88% of background of the author. Also, dig deeper! In science, movement to protest scientists say a single research study is rarely a complete answer. Monsanto Corporation’s GMOs are safe. Based on hundreds of scientific studies, the American production of GMO crops. Medical Association (AMA), takes the position that Group members want labeling to be required for bioengineered (GMO) crops and foods offer many potential benefits and encourages ongoing research developments in food biotechnology. However, food containing GMOs. the AMA also supports mandatory safety assessments of bioengineered foods and development of more ways to detect unintended harmful effects. A National Academy of Sciences report on GMO safety points out that traditional breeding methods can also have unintended effects, such as a case where scientists bred the cultivated potato with a wild potato. The hybrid (a product of two kinds of parents) produced a toxic chemical called demissidine, even though neither parent had contained it. Don’t Forget Diversity! As we’ve seen, each GMO is engineered to do Do herbicide- a specific job. So, people’s questions and resistant GMOs Whether food is developed by concerns vary depending on the GMO. promote development of selective breeding or genetic Some examples follow. herbicide-resistant weeds? engineering, genetic diversity is the “library” of source material  Herbicides can be used on we have to work with! Will antibiotic-resistant genes in GMOs create herbicide-resistant GMOs to kill antibiotic-resistant bacteria in our bodies?  surrounding weeds without harming If everyone plants the same Antibiotic-resistant genes are used to make some GMOs. the crops. Weeds rapidly evolve to resist kinds of crops, genetic traits These genes are already common in bacteria naturally the herbicide and can invade farmlands. in less popular varieties can found in soil and in human bodies, and they don’t seem to Also, in very limited cases, herbicide- be lost forever. The thousands cause a problem. However, antibiotic resistance overall is resistant GMOs can crossbreed of undiscovered genes in less popular varieties may have a health concern, and some GMO producers are replacing with close relatives and pass on the potential to help produce antibiotic-resistant genes with other types of genes. the resistance gene. If these crossbred plants become better growing, better tasting, invasive, it could be a and more nutritious food. Will RNA used to turn off problem. genes in GMOs like arctic apples turn off Aside from producing tasty food, our genes?  Small RNA molecules (called miRNA) exist growers of heirloom fruits and (varieties introduced in all plants and animals and can turn genes on or off. New miRNA vegetables 50+ years ago) are helping to is inserted in some GMO crops to change how genes are expressed. Some preserve genetic diversity that people worry that we will absorb this inserted miRNA when we eat the food, would otherwise be lost. and the miRNA will turn off some of our genes. However, the action of miRNA is very specific, so miRNA that targets genes in plants is not likely to affect humans. Also, many studies show that DNA and RNA from foods are broken up in digestion and don’t get HEIRLOOM TOMATOES absorbed in a working form. COME IN MANY SHAPES Should we go with GMOs? 4 AND COLORS!