Melissa J. Blake
Josie Tierney-Fife
English 9 Advanced
22 March 2010
America’s Genetically Engineered Animals
Close your eyes and imagine the perfect animal. What do you see? A cow that produces twice as much milk a day as the others? A chicken that lays every single day instead of every few days? Maybe something that is as crazy as an animal that produces medication in its salvia, or that grows human organs instead of its normal ones. Open your eyes. All this and more is possible thanks to the modern science of genetic engineering. Genetic engineering is the process in which recombinant DNA (rDNA) is used to introduce desirable traits into organisms (“FDA Genetic Engineering”). Scientists splice together pieces of DNA and introduce the new DNA segment into an animal to give it new properties and change its DNA composition (“FDA Fact Sheet”). The Genetically engineered animals, abbreviated to a GE animals, contain a recombinant DNA construct that produces a new trait (“FDA Genetic Engineering”). This entails producing a rDNA construct. The genes or segments of DNA that are part of the rDNA construct may be obtaining from other organisms or synthesized from scratch in the lab. The only difference between a GE animal and its conventional counterpart, from a scientific perspective, is the rDNA construct (“FDA Genetically Engineered Animals Q&A”).
Inheritance
Most GE animals pass their new GE traits to their offspring. These traits are called heritable. With heritable traits, the initial GE animal and all its descendants have inherited GE traits. Generally, most GE animals contain rDNA constructs that were introduced in early embryos, or cells that go on to form embryos in the GE animal. These constructs will be heritable due to the fact that they will be in every cell of the resulting animal as the cells multiply. This includes those that are responsible for making reproduction cells for the next generation. An example of those GE animals who do not pass on their traits to the next generation are animals being treated with certain kinds of gene therapy, which is the treatment of genetic diseases and defects through correction of the DNA sequence. These kinds of rDNA constructs are not found in the germ cells of the animals and therefore not passed on to the offspring (“FDA Genetically Engineered Animals Q&A”).
Many times cloning is confused with genetic engineering, but they are different. It really comes down to DNA and offspring. Animal cloning is a method of asexual reproduction that produces the birth of one animal, the clone, which is a genetic copy of the animal cloned. These clones have no new genes, they are just a copy of another animal. Should the clone reproduce, the offspring are not clones, because they were born through sexual reproduction and not a copy of the parent clone. They contain new DNA from the parent animal who was not the clone. Genetic Engineering is a method of introducing new genes into an animal, thus, a method of altering an animal, not copying the animal. If the rDNA construct is stably inherited, then future generations of this GE animal will also contain the construct. This said, the GE traits generally continue into the next generation, while cloning does not (“FDA Genetically Engineering Animals Q&A”). Clones are a genetic copy of another animal born through asexual reproduction, while GE animals have their own, but manipulated, DNA and are born through sexual reproduction.
Types
Genetically Engineered animals are produced for many reasons. The largest group of GE animals currently being produced are being developed for biopharm purposes. They are created to produce substances, milk, blood, etc., used for human or animal pharmaceuticals. Other animals are under development for use as sources of scarce cells, tissues, and organs for human transplant (xenotransplant sources), and to serve as a source of cells, tissue, and organs closely matched to humans so they can be transplanted without rejection (“FDA Genetically Engineered Animals Q&A, FDA Fact Sheet”). Genetically engineered animals produce surgical sutures and personal protection devices, such as, body armor for the military and law enforcement. Genetically engineered livestock are also created to decrease the environmental impact of large-scale agricultural practices by doing things like decreasing the amount of phosphate in manure. Phosphate causes algae blooms, which is harmful aquatic life. Animals are created to produce highly specific antimicrobial that target disease-causing bacteria, or to just simply provide more healthful and efficiently produced food. Animals have been genetically engineered with new traits for things like disease resistance, drought, or heat tolerance to give an opportunity to raise these animals or produce high quality food by them in parts of the world where these animals could have never thrived before (“FDA Fact Sheet”). Genetically engineered animals are created for many purposes and have broadened the horizons for what animals and their creators can accomplish.
Of course, animals are not the only thing being genetically engineered. Genetic Engineering is widely used in agriculture for many purposes. Crops can be made resistant to certain pests or herbicides through genetically engineering them specific traits blocking these pests and herbicides (“FDA Genetically Engineered Animals Q&A”). Sometimes animal genes are even injected into plants to give them certain characteristics from those animals. For example, frog DNA being inserted into fruits to make them stay fresher longer in some countries (Mulrey). Other purposes are for things like creating microbes that produce pharmaceuticals, and microorganisms to aid in baking, brewing, and cheese-making. Genetic Engineering is used in many ways, and not just in animals (“FDA Genetically Engineered Animals Q&A”).
Regulation
The FDA regulates GE animals and the products under the drug provisions under the Federal Food, Drug, and Cosmetic act. They define a new animal drug as “an article (other than food) intended to effect the structure or any function of the body of ... animals” (“FDA Genetically Engineered Animals Q&A”). The recombinant DNA construct meets the definition of a new animal drug, no matter if the animal is intended food, pharmaceuticals, or any other substance (“FDA Genetically Engineered animals Q&A”).
The elements of the drug approval process are: product definition, a broad statement characterizing the GE animal and the claim that is being made about it, and molecular characterization of the construct. This is a description of the rDNA construct and how it is constructed. The next are: molecular characterization of the GE animal lineage, a description of the method by which the rDNA construct was introduced into the animal and whether or not the rDNA construct is stably maintained over time, phenotypic characterization, the comprehensive data on the characteristics and health of the GE animal. The durability plan comes next, and that is the sponsor’s plan to demonstrate the modification will remain the same and have the same effect over time. Environmental and food/feed safety come next. That is the assessment of any environmental impacts of the animal and that the food is safe for human or animal consumption, for the animals intended for food. The last one is Claim Validation, to demonstrate that the GE animal does fulfill the product definition stated above (“FDA Genetically Engineered Animals Q&A”).
The Center of Veterinary Medicine is responsible for evaluating the safety and effectiveness of the rDNA construct in the new GE animal. This includes the safety of the products of the GE animals. The CMV is also responsible for evaluating whether the animal has the properties it has been claimed to have. The CMV will consult the Center of Food Safety and Applied Nutrition on food safety when a question arrises requiring expertise that CFSAN has and the CVM does not. The Center for Drug Evaluation and Research, the Center for Biologics Evaluation and Research, or the Center for Devices and Radiological Health have the responsibility for approving the respective product of animals producing substances used in drugs, biologics, or devices in humans. The Animal and Plant Health Inspection Service regulates veterinary biologic produced by GE animals, as well as licensing any veterinary biological products derived from genetic engineering.
The APHIS is authorized to protect the heath of U.S. livestock under the Animal Health Protection Act. Due to this, they may broadly consider the potential of genetically engineered animals on the health of the overall American Livestock population when they are regulating GE animals and their products. The APHIS addresses The Food Safety and and Inspection Service ensures that meat, meat, poultry, and egg products are safe, wholesome, and properly labeled based on tolerance set up by the FDA on new animal drug residues in like products. This is under the Federal Meat Inspection Act, the Poultry Products Act, and the Egg Inspection Act. Under the Animal Welfare Act, the USDA addresses animal welfare concerns of certain animals.
Developers of Genetically Engineered animals are welcome to come to the FDA with any questions regarding the premarket approval of their animals; in fact, they are recommended to come to the agency early on in the development of their GE animals. Then, the agency can work closely with them during the investigational phase of the development of the GE animals. The FDA will work with sponsors to ensure that records are kept properly, that all investigational animals are disposed in a safe manner where as all potential environmental risks are assessed, and that the data and information being developed is suitable to a New Animal Drug Application. During the agency investigational phase of the GE animals containing rDNA constructs, the developers, also called sponsors, can generally use various rDNA constructs and intermediates to arrive at a construct in an animal that they believe will serve as a progenitor of the line of animals they wish to develop (“FDA Genetically Engineered Animals Q&A”).
Should a marketer wish to import food into the US from a Genetically Engineered animal, the FDA has a mechanism by which they can evaluate the safety of food from these GE animals developed abroad. After this evaluation, they then can establish an import tolerance over them. The United States of America is also a functioning participant in a number of international organizations addressing Genetically Engineered animal and their products. This includes Codex Alimentarius and the World Organization for Animal Health (“FDA Genetically Engineered Animals Q&A”).
The FDA has taken a different approach to regulating clones versus genetically engineered animals. After a risk assessment, the agency was able to determine that clones fell under the continuum of assisted reproductive technologies, so cloning poses no new risk to the animals involved or the products from them. GE animals have been intentionally changed. This may have effected the health of the animals as well as the safety of their products. Between GE plants and GE animals, most of the safety issues are the same; however, GE animals may produce new zoonotic diseases (“FDA Genetically Engineered Animals Q&A”). America has a strict regulatory process, involving many pieces of the US government, due to the potential dangers of genetically engineered animals and their products.
Examples
In early 2010, scientists assembled the first full genetic code from laboratory chemicals and used it to create a living organism. They did this by transplanting their synthetic DNA into a genetically empty husk of a microbe. The microbe then came to life. The organism was a replica of an existing type of bacterium called M. mycoides, along with a few extra pieces of DNA, sort of “watermarks”, to show that synthetic DNA was running the cells. The creation multiplied and grew. Some biologists argue over whether this bacterium can be considered a creation from non-life, as it involved parts of existing life. Since the 1950’s scientists have been hoping and trying to create life from inanimate matter, some hoping the that the synthetic organism would shed light onto the origin of life (Flam).
The quest for this particular organism started 15 years ago, when geneticist J. Craig Venter and other prominent biologists thought they might have found a way to create life. They wrote out a genetic code on a computer, synthesized the DNA, and transplanted it into a bacterium. To do this they had to first move their small stretches of synthetic DNA into yeast, which contained enzymes that “stitched” the pieces of DNA together. They then had to remove the DNA from the yeast and put it in the bacterium. The next step was to get the DNA to take effect inside an genetically empty bacterium, which was difficult. They were forced to switch to bacterium they were using from the original M. genitalium to the M. mycoides, which carries a much larger DNA code. After many false starts, the first colony was started in late March of 2010. The scientists continued to manipulate the DNA, giving the bacterium its blue color, and adding DNA that could be decoded into the alphabet spelling out the researchers’ names and several quotes (Flam).
On February 6, 2009, the first drug produced by livestock was approved by the FDA, along with the animals making the drug. The drug, meant to prevent fatal blood clots in humans with a rare hereditary deficiency of antithrombin, is a protein extracted from the milk of GTC Biotherapeutics genetically engineered goats. GTC extracted the human gene producing antithrombin and linked it in with normal goat DNA that controls the production of the protein in their milk. This gene was injected into a goat embryo, which was then implanted in a surrogate mother. The result was the birth of a goat who produced antithrombin in its milk. The herd was expanded to a 200 goat herd living on a carefully controlled farm in Massachusetts through conventional breeding. The existing method for acquiring antithrombin is to remove it from blood donations or grow it in large vats. Antithrombin is often in short supply or unattainable, as the methods to produce it do not do so efficiently enough to meet demands for the protein. One GE goat is able to produce 90,000 blood donations worth of antithrombin in one year, greatly increasing the amount of antithrombin available. This is the first drug from animals created specifically to serve as living pharmaceutical producers (Pollack).
In late 2007, scientists cured sickle cell anemia in mice by rewinding their skin cells to an embryonic state and manipulating them to create healthy, genetically matched replacement tissue. The repaired cells were transfused into the mice and soon were producing healthy cells free of the deformities of sickle cell anemia that deprive organs of oxygen. Researchers started with sickle cell anemia be cause it had a simple origin at the key point in the hemoglobin beta gene. These patients have a misspelling in the chemical letters of DNA causing sickle cell anemia. The sequence of DNA should go A, C, T, and G, but instead of at least one A, the mice with sickle cell anemia have a pair of T’s. This causes the the gene to make the wrong amino acid, resulting in blood cells that are being made curved instead of round. These cells have a tendency to clot and block the flow of blood and oxygen to small vessels that feed the brain, kidneys, and other organs, killing tissues. To fix this genetic glitch, scientists clone embryos using the patient’s DNA, switch one of the errant T’s into an A, then stem cells would be harvested from the modified embryo. Those cells are then used to make healthy bone marrow. A researcher at the Broad Center of Regenerative Medicine and Stem Cell Research at UCLA, Kathrin Plath, was not involved in the study, but commented “It really works beautifully”(Kaplan).
The researchers then wanted to see if iPS cells would work instead of embryonic stem cells so they teamed to with Rudolf Jaenisch, a stem cell researcher at Whitehead and MIT, to see if they could. To do this, researchers took cells from the tail of a twelve week old mouse with sickle cell anemia, then used viruses to turn on four dormant genes that are active in day-old embryos. One of those genes, c-Myc, has a tendency to cause tumors. After the cells had completed their transition back to the embryonic state, researchers removed the gene. They then corrected the the genetic flaw that causes sickle cell anemia by engineering the correct trying of DNA and swapping into place with the help of an electrical shock. Bone marrow was grown from the iPS cells by exposing them to special growth factors and culture conditions. The cells were then transplanted into three sick mice that were genetic twins of the donor mouse, and after twelve weeks the mice were producing the normal version of hemoglobin beta protein, virtually all blood cells were round, body weight and respiratory capacity had improved, and their urine had returned to the normal level of electrolytes. Using stem cells and iPS cells, researchers have cured sickle cell anemia in mice (Kaplan).
Not all genetic engineering is done in America. Genetically modified mosquitoes were released into South East Asia to curb South Asia’s deadly dengue fever. The Malaysian Institute for Medical Research, released 6000 GE male mosquitoes and 6000 regular male mosquitoes, for comparison, on December 21, 2010. The Mosquitoes were released in an uninhabited area near the town of Bentong, Malaysia on a trial basis to see how the mosquitoes disperse in the wild and how long the mosquitoes live for. The trial was successfully completed on January 5, 2011. These male mosquitoes, developed by Oxford biotechnology, carry artificial DNA fragments designed to curb fertility. The offspring of the males have been passed on a gene designed to kill the insects at the larval stage of its lifecycle. The mosquitoes will mate with the wild females and decrease wild populations. This will reduce the spread of the Dengue fever, which is a severe flu-like illness spread by the aedes mosquito, which is growing in population and prefers urban areas. Dengue can become a potentially lethal combination called dengue haemorrhagic fever, the leading cause of serious illness and death among children in some Asian countries. This mosquito’s DNA defect can not be transmitted to other animals as there are only two options for the mosquitoes, mate and producing dying offspring then die, or not to mate and die (Connor).
Many different types of animals have been created in the laboratory. Microbes containing completely synthetic DNA are living and multiplying. A herd of goats producing a human protein used to make medication in its milk live in Massachusetts. Sickle cell anemia in mice has been cured using iPS and stem cells. Also, mosquitoes have been created with artificial DNA designed to kill their young. This should shrink the mosquito population and limit the spread of the dengue fever, a mosquito spread disease. This may be a lot of examples, but it is only a fragment of what is being done today.
Pros and Cons
Genetic Engineering in animals is a highly controversial subject. Many people have strong feelings about the issue either way. Those who view genetic engineering in animals as a positive thing often feel that it beneficial for all. Animals designed to produce more meat, milk, eggs, etc. will lower the costs of food, as it would lower the cost of maintaing animals since a smaller amount of animals are producing more products (Mulrey). Less farm land would be needed, and accordingly less of an impact on the environment (Dresen). Genetically Engineered animals are also created to decrease the environmental impact of large-scale agricultural practices by doing things like decreasing the amount of phosphate on manure. Animals being created with traits for disease, heat, cold, and drought resistance can expand the health of animals, and therefore the health of your food. This tolerance for diseases and environmental conditions makes it possible to raise animals and get decent products from them in places where they never could have thrived before (“FDA Fact Sheet”). GE animals that produce pharmaceuticals provide natural production systems for therapeutic proteins which were previously thought to only be available through purification of human cadavers or animal carcasses, creating opportunities to gain pharmaceuticals on a scale to meet with demands. GE animals can produce organs, tissues, etc. that can be used for transplant in other animals and humans (“FDA Fact Sheet”). Genes can be decoded, and defective ones can be fixed through gene therapy, which is essentially rewriting DNA to fix defects through various forms. The possibilities are endless. Everyday scientists learn more about animals, and in turn ourselves, through genetic engineering. We can now fix animals with defects and change animals for the greater good (Mulrey).
Just as there are many reasons to support genetic engineering in animals, there are many reasons to not support it. Genetic Engineering could harm the farming industry, as they would not need as much livestock to meet the demand for produce. There would not be as much of a need for animal feed, because animals can be created to live on less food, harming that industry (Dresen). Many worry that by manipulating animal genes we could create new animal diseases and zoonoses, diseases transmittable from animals to people and back, that could harm humans and animals. Some wonder whether genetically engineered traits will cause defects in the animal or its offspring. Both could harm the health of conventional animal populations overtime. Others worry if the new products from GE animals are really safe. Gregory Jaffe of the Center for Science in the Public Interest called for assurances that the genetically engineered goats do not accidentally enter the food supply, saying that “Humans are fallible; accidents happen” (Pollack). Pen Caplan, who headed the original ethical review, referred to the ways manipulating the living world had backfired when he said “Think of Kudzu, or Japanese beetles or the rabbits that went nuts reproducing is Australia” when he commented on the first lab created microbe mentioned before (Flam). The Kudzu, Japanese beetles, and rabbits are invasive species which reek havoc in the land they are introduced to. They overpopulate and harm the native ecosystem. People are worried. Since some animals treated with gene therapy through viral vectors, using viruses to introduce new DNA into an animal body, could the viruses harm the people consuming the animals or their young?
Questions and thoughts like those mentioned before spark much of the controversy between the proponents of genetic engineering and those who oppose it. Although, no questions spark more controversy than ethical questions. People wonder if it is “ethical” to manipulate animal DNA and “play God” like scientists now do everyday. They worry about the quality of life that these lab creations have. Could it be fair to hurt animals for human benefit (Mulrey)? Of course, using genetic engineering, pharmaceuticals can be made, diseases can be cured, and faster growing, healthier produce can be created. These views spark the classic practicality versus ethics debate. This said, there is no correct way to view genetic engineering. It all depends on what you believe is right and what is wrong.
In conclusion, genetic engineering is the process in which recombinant DNA is used to introduce desirable traits into organisms. The DNA is either taken form existing organisms or created in a laboratory. Even fully made artificial DNA sequences is being made by scientists. Genetic engineering is done in animals for many reasons, among these are to produce pharmaceuticals on a greater scale, create more healthful efficiently produced food, and animal resistant to certain diseases and extreme environmental conditions. Animals are regulated strictly by the government to ensure they pose no new risks to humans, animals, and the environment. There is much debate over whether genetic engineering in animals is a good or bad thing, but it really comes down to a fight over practicality versus ethics. Like it or not, genetic engineering is coming, creating the creatures of the future.
Works Cited
Dresen, Cally. E-mail correspondence. 2 Mar. 2011.
“Fact Sheet: Genetically Engineered Animals.” FDA U.S. Food and Drug Administration. FDA U.S. Food and Drug Administration, 28 Oct. 2009.Web. 1 Feb. 2011.
Flam, Faye. “Advance of Horror: the First Lab-Created Organism.” Philadelphia Inquirer.(21 May 2010): A.1. SIRS. Web. 7 Feb. 2011.
“GM mosquitoes deployed to control Asia’s dengue fever”. The Independent: Science. independent.co.uk, 27 Jan. 2011. Web. 7 Feb. 2011.
“General Q&A: The Technology.” FDA U.S. Food and Drug Administration. FDA U.S. Food and Drug Administration, July 1, 2009.Web. 1 Feb. 2011.
“Genetic Engineering.” FDA U.S. Food and Drug Administration. FDA U.S. Food and Drug Administration, 30 April 2009.Web. 1 Feb. 2011.
Kaplan, Karen. “Stem Cell Method Finds Cure.” Los Angeles Times. (7 Dec. 2007). SIRS. Web. 7 Feb. 2011.
Mulrey, Stacy. Personal interview. 4 Mar. 2011.
Pollack, Andrew. “Drug from a Goat With a Human Gene.” New York Times. (7 Feb. 2009): B.1. SIRS. Web. 7 Feb. 2011.
Josie Tierney-Fife
English 9 Advanced
22 March 2010
America’s Genetically Engineered Animals
Close your eyes and imagine the perfect animal. What do you see? A cow that produces twice as much milk a day as the others? A chicken that lays every single day instead of every few days? Maybe something that is as crazy as an animal that produces medication in its salvia, or that grows human organs instead of its normal ones. Open your eyes. All this and more is possible thanks to the modern science of genetic engineering. Genetic engineering is the process in which recombinant DNA (rDNA) is used to introduce desirable traits into organisms (“FDA Genetic Engineering”). Scientists splice together pieces of DNA and introduce the new DNA segment into an animal to give it new properties and change its DNA composition (“FDA Fact Sheet”). The Genetically engineered animals, abbreviated to a GE animals, contain a recombinant DNA construct that produces a new trait (“FDA Genetic Engineering”). This entails producing a rDNA construct. The genes or segments of DNA that are part of the rDNA construct may be obtaining from other organisms or synthesized from scratch in the lab. The only difference between a GE animal and its conventional counterpart, from a scientific perspective, is the rDNA construct (“FDA Genetically Engineered Animals Q&A”).
Inheritance
Most GE animals pass their new GE traits to their offspring. These traits are called heritable. With heritable traits, the initial GE animal and all its descendants have inherited GE traits. Generally, most GE animals contain rDNA constructs that were introduced in early embryos, or cells that go on to form embryos in the GE animal. These constructs will be heritable due to the fact that they will be in every cell of the resulting animal as the cells multiply. This includes those that are responsible for making reproduction cells for the next generation. An example of those GE animals who do not pass on their traits to the next generation are animals being treated with certain kinds of gene therapy, which is the treatment of genetic diseases and defects through correction of the DNA sequence. These kinds of rDNA constructs are not found in the germ cells of the animals and therefore not passed on to the offspring (“FDA Genetically Engineered Animals Q&A”).
Many times cloning is confused with genetic engineering, but they are different. It really comes down to DNA and offspring. Animal cloning is a method of asexual reproduction that produces the birth of one animal, the clone, which is a genetic copy of the animal cloned. These clones have no new genes, they are just a copy of another animal. Should the clone reproduce, the offspring are not clones, because they were born through sexual reproduction and not a copy of the parent clone. They contain new DNA from the parent animal who was not the clone. Genetic Engineering is a method of introducing new genes into an animal, thus, a method of altering an animal, not copying the animal. If the rDNA construct is stably inherited, then future generations of this GE animal will also contain the construct. This said, the GE traits generally continue into the next generation, while cloning does not (“FDA Genetically Engineering Animals Q&A”). Clones are a genetic copy of another animal born through asexual reproduction, while GE animals have their own, but manipulated, DNA and are born through sexual reproduction.
Types
Genetically Engineered animals are produced for many reasons. The largest group of GE animals currently being produced are being developed for biopharm purposes. They are created to produce substances, milk, blood, etc., used for human or animal pharmaceuticals. Other animals are under development for use as sources of scarce cells, tissues, and organs for human transplant (xenotransplant sources), and to serve as a source of cells, tissue, and organs closely matched to humans so they can be transplanted without rejection (“FDA Genetically Engineered Animals Q&A, FDA Fact Sheet”). Genetically engineered animals produce surgical sutures and personal protection devices, such as, body armor for the military and law enforcement. Genetically engineered livestock are also created to decrease the environmental impact of large-scale agricultural practices by doing things like decreasing the amount of phosphate in manure. Phosphate causes algae blooms, which is harmful aquatic life. Animals are created to produce highly specific antimicrobial that target disease-causing bacteria, or to just simply provide more healthful and efficiently produced food. Animals have been genetically engineered with new traits for things like disease resistance, drought, or heat tolerance to give an opportunity to raise these animals or produce high quality food by them in parts of the world where these animals could have never thrived before (“FDA Fact Sheet”). Genetically engineered animals are created for many purposes and have broadened the horizons for what animals and their creators can accomplish.
Of course, animals are not the only thing being genetically engineered. Genetic Engineering is widely used in agriculture for many purposes. Crops can be made resistant to certain pests or herbicides through genetically engineering them specific traits blocking these pests and herbicides (“FDA Genetically Engineered Animals Q&A”). Sometimes animal genes are even injected into plants to give them certain characteristics from those animals. For example, frog DNA being inserted into fruits to make them stay fresher longer in some countries (Mulrey). Other purposes are for things like creating microbes that produce pharmaceuticals, and microorganisms to aid in baking, brewing, and cheese-making. Genetic Engineering is used in many ways, and not just in animals (“FDA Genetically Engineered Animals Q&A”).
Regulation
The FDA regulates GE animals and the products under the drug provisions under the Federal Food, Drug, and Cosmetic act. They define a new animal drug as “an article (other than food) intended to effect the structure or any function of the body of ... animals” (“FDA Genetically Engineered Animals Q&A”). The recombinant DNA construct meets the definition of a new animal drug, no matter if the animal is intended food, pharmaceuticals, or any other substance (“FDA Genetically Engineered animals Q&A”).
The elements of the drug approval process are: product definition, a broad statement characterizing the GE animal and the claim that is being made about it, and molecular characterization of the construct. This is a description of the rDNA construct and how it is constructed. The next are: molecular characterization of the GE animal lineage, a description of the method by which the rDNA construct was introduced into the animal and whether or not the rDNA construct is stably maintained over time, phenotypic characterization, the comprehensive data on the characteristics and health of the GE animal. The durability plan comes next, and that is the sponsor’s plan to demonstrate the modification will remain the same and have the same effect over time. Environmental and food/feed safety come next. That is the assessment of any environmental impacts of the animal and that the food is safe for human or animal consumption, for the animals intended for food. The last one is Claim Validation, to demonstrate that the GE animal does fulfill the product definition stated above (“FDA Genetically Engineered Animals Q&A”).
The Center of Veterinary Medicine is responsible for evaluating the safety and effectiveness of the rDNA construct in the new GE animal. This includes the safety of the products of the GE animals. The CMV is also responsible for evaluating whether the animal has the properties it has been claimed to have. The CMV will consult the Center of Food Safety and Applied Nutrition on food safety when a question arrises requiring expertise that CFSAN has and the CVM does not. The Center for Drug Evaluation and Research, the Center for Biologics Evaluation and Research, or the Center for Devices and Radiological Health have the responsibility for approving the respective product of animals producing substances used in drugs, biologics, or devices in humans. The Animal and Plant Health Inspection Service regulates veterinary biologic produced by GE animals, as well as licensing any veterinary biological products derived from genetic engineering.
The APHIS is authorized to protect the heath of U.S. livestock under the Animal Health Protection Act. Due to this, they may broadly consider the potential of genetically engineered animals on the health of the overall American Livestock population when they are regulating GE animals and their products. The APHIS addresses The Food Safety and and Inspection Service ensures that meat, meat, poultry, and egg products are safe, wholesome, and properly labeled based on tolerance set up by the FDA on new animal drug residues in like products. This is under the Federal Meat Inspection Act, the Poultry Products Act, and the Egg Inspection Act. Under the Animal Welfare Act, the USDA addresses animal welfare concerns of certain animals.
Developers of Genetically Engineered animals are welcome to come to the FDA with any questions regarding the premarket approval of their animals; in fact, they are recommended to come to the agency early on in the development of their GE animals. Then, the agency can work closely with them during the investigational phase of the development of the GE animals. The FDA will work with sponsors to ensure that records are kept properly, that all investigational animals are disposed in a safe manner where as all potential environmental risks are assessed, and that the data and information being developed is suitable to a New Animal Drug Application. During the agency investigational phase of the GE animals containing rDNA constructs, the developers, also called sponsors, can generally use various rDNA constructs and intermediates to arrive at a construct in an animal that they believe will serve as a progenitor of the line of animals they wish to develop (“FDA Genetically Engineered Animals Q&A”).
Should a marketer wish to import food into the US from a Genetically Engineered animal, the FDA has a mechanism by which they can evaluate the safety of food from these GE animals developed abroad. After this evaluation, they then can establish an import tolerance over them. The United States of America is also a functioning participant in a number of international organizations addressing Genetically Engineered animal and their products. This includes Codex Alimentarius and the World Organization for Animal Health (“FDA Genetically Engineered Animals Q&A”).
The FDA has taken a different approach to regulating clones versus genetically engineered animals. After a risk assessment, the agency was able to determine that clones fell under the continuum of assisted reproductive technologies, so cloning poses no new risk to the animals involved or the products from them. GE animals have been intentionally changed. This may have effected the health of the animals as well as the safety of their products. Between GE plants and GE animals, most of the safety issues are the same; however, GE animals may produce new zoonotic diseases (“FDA Genetically Engineered Animals Q&A”). America has a strict regulatory process, involving many pieces of the US government, due to the potential dangers of genetically engineered animals and their products.
Examples
In early 2010, scientists assembled the first full genetic code from laboratory chemicals and used it to create a living organism. They did this by transplanting their synthetic DNA into a genetically empty husk of a microbe. The microbe then came to life. The organism was a replica of an existing type of bacterium called M. mycoides, along with a few extra pieces of DNA, sort of “watermarks”, to show that synthetic DNA was running the cells. The creation multiplied and grew. Some biologists argue over whether this bacterium can be considered a creation from non-life, as it involved parts of existing life. Since the 1950’s scientists have been hoping and trying to create life from inanimate matter, some hoping the that the synthetic organism would shed light onto the origin of life (Flam).
The quest for this particular organism started 15 years ago, when geneticist J. Craig Venter and other prominent biologists thought they might have found a way to create life. They wrote out a genetic code on a computer, synthesized the DNA, and transplanted it into a bacterium. To do this they had to first move their small stretches of synthetic DNA into yeast, which contained enzymes that “stitched” the pieces of DNA together. They then had to remove the DNA from the yeast and put it in the bacterium. The next step was to get the DNA to take effect inside an genetically empty bacterium, which was difficult. They were forced to switch to bacterium they were using from the original M. genitalium to the M. mycoides, which carries a much larger DNA code. After many false starts, the first colony was started in late March of 2010. The scientists continued to manipulate the DNA, giving the bacterium its blue color, and adding DNA that could be decoded into the alphabet spelling out the researchers’ names and several quotes (Flam).
On February 6, 2009, the first drug produced by livestock was approved by the FDA, along with the animals making the drug. The drug, meant to prevent fatal blood clots in humans with a rare hereditary deficiency of antithrombin, is a protein extracted from the milk of GTC Biotherapeutics genetically engineered goats. GTC extracted the human gene producing antithrombin and linked it in with normal goat DNA that controls the production of the protein in their milk. This gene was injected into a goat embryo, which was then implanted in a surrogate mother. The result was the birth of a goat who produced antithrombin in its milk. The herd was expanded to a 200 goat herd living on a carefully controlled farm in Massachusetts through conventional breeding. The existing method for acquiring antithrombin is to remove it from blood donations or grow it in large vats. Antithrombin is often in short supply or unattainable, as the methods to produce it do not do so efficiently enough to meet demands for the protein. One GE goat is able to produce 90,000 blood donations worth of antithrombin in one year, greatly increasing the amount of antithrombin available. This is the first drug from animals created specifically to serve as living pharmaceutical producers (Pollack).
In late 2007, scientists cured sickle cell anemia in mice by rewinding their skin cells to an embryonic state and manipulating them to create healthy, genetically matched replacement tissue. The repaired cells were transfused into the mice and soon were producing healthy cells free of the deformities of sickle cell anemia that deprive organs of oxygen. Researchers started with sickle cell anemia be cause it had a simple origin at the key point in the hemoglobin beta gene. These patients have a misspelling in the chemical letters of DNA causing sickle cell anemia. The sequence of DNA should go A, C, T, and G, but instead of at least one A, the mice with sickle cell anemia have a pair of T’s. This causes the the gene to make the wrong amino acid, resulting in blood cells that are being made curved instead of round. These cells have a tendency to clot and block the flow of blood and oxygen to small vessels that feed the brain, kidneys, and other organs, killing tissues. To fix this genetic glitch, scientists clone embryos using the patient’s DNA, switch one of the errant T’s into an A, then stem cells would be harvested from the modified embryo. Those cells are then used to make healthy bone marrow. A researcher at the Broad Center of Regenerative Medicine and Stem Cell Research at UCLA, Kathrin Plath, was not involved in the study, but commented “It really works beautifully”(Kaplan).
The researchers then wanted to see if iPS cells would work instead of embryonic stem cells so they teamed to with Rudolf Jaenisch, a stem cell researcher at Whitehead and MIT, to see if they could. To do this, researchers took cells from the tail of a twelve week old mouse with sickle cell anemia, then used viruses to turn on four dormant genes that are active in day-old embryos. One of those genes, c-Myc, has a tendency to cause tumors. After the cells had completed their transition back to the embryonic state, researchers removed the gene. They then corrected the the genetic flaw that causes sickle cell anemia by engineering the correct trying of DNA and swapping into place with the help of an electrical shock. Bone marrow was grown from the iPS cells by exposing them to special growth factors and culture conditions. The cells were then transplanted into three sick mice that were genetic twins of the donor mouse, and after twelve weeks the mice were producing the normal version of hemoglobin beta protein, virtually all blood cells were round, body weight and respiratory capacity had improved, and their urine had returned to the normal level of electrolytes. Using stem cells and iPS cells, researchers have cured sickle cell anemia in mice (Kaplan).
Not all genetic engineering is done in America. Genetically modified mosquitoes were released into South East Asia to curb South Asia’s deadly dengue fever. The Malaysian Institute for Medical Research, released 6000 GE male mosquitoes and 6000 regular male mosquitoes, for comparison, on December 21, 2010. The Mosquitoes were released in an uninhabited area near the town of Bentong, Malaysia on a trial basis to see how the mosquitoes disperse in the wild and how long the mosquitoes live for. The trial was successfully completed on January 5, 2011. These male mosquitoes, developed by Oxford biotechnology, carry artificial DNA fragments designed to curb fertility. The offspring of the males have been passed on a gene designed to kill the insects at the larval stage of its lifecycle. The mosquitoes will mate with the wild females and decrease wild populations. This will reduce the spread of the Dengue fever, which is a severe flu-like illness spread by the aedes mosquito, which is growing in population and prefers urban areas. Dengue can become a potentially lethal combination called dengue haemorrhagic fever, the leading cause of serious illness and death among children in some Asian countries. This mosquito’s DNA defect can not be transmitted to other animals as there are only two options for the mosquitoes, mate and producing dying offspring then die, or not to mate and die (Connor).
Many different types of animals have been created in the laboratory. Microbes containing completely synthetic DNA are living and multiplying. A herd of goats producing a human protein used to make medication in its milk live in Massachusetts. Sickle cell anemia in mice has been cured using iPS and stem cells. Also, mosquitoes have been created with artificial DNA designed to kill their young. This should shrink the mosquito population and limit the spread of the dengue fever, a mosquito spread disease. This may be a lot of examples, but it is only a fragment of what is being done today.
Pros and Cons
Genetic Engineering in animals is a highly controversial subject. Many people have strong feelings about the issue either way. Those who view genetic engineering in animals as a positive thing often feel that it beneficial for all. Animals designed to produce more meat, milk, eggs, etc. will lower the costs of food, as it would lower the cost of maintaing animals since a smaller amount of animals are producing more products (Mulrey). Less farm land would be needed, and accordingly less of an impact on the environment (Dresen). Genetically Engineered animals are also created to decrease the environmental impact of large-scale agricultural practices by doing things like decreasing the amount of phosphate on manure. Animals being created with traits for disease, heat, cold, and drought resistance can expand the health of animals, and therefore the health of your food. This tolerance for diseases and environmental conditions makes it possible to raise animals and get decent products from them in places where they never could have thrived before (“FDA Fact Sheet”). GE animals that produce pharmaceuticals provide natural production systems for therapeutic proteins which were previously thought to only be available through purification of human cadavers or animal carcasses, creating opportunities to gain pharmaceuticals on a scale to meet with demands. GE animals can produce organs, tissues, etc. that can be used for transplant in other animals and humans (“FDA Fact Sheet”). Genes can be decoded, and defective ones can be fixed through gene therapy, which is essentially rewriting DNA to fix defects through various forms. The possibilities are endless. Everyday scientists learn more about animals, and in turn ourselves, through genetic engineering. We can now fix animals with defects and change animals for the greater good (Mulrey).
Just as there are many reasons to support genetic engineering in animals, there are many reasons to not support it. Genetic Engineering could harm the farming industry, as they would not need as much livestock to meet the demand for produce. There would not be as much of a need for animal feed, because animals can be created to live on less food, harming that industry (Dresen). Many worry that by manipulating animal genes we could create new animal diseases and zoonoses, diseases transmittable from animals to people and back, that could harm humans and animals. Some wonder whether genetically engineered traits will cause defects in the animal or its offspring. Both could harm the health of conventional animal populations overtime. Others worry if the new products from GE animals are really safe. Gregory Jaffe of the Center for Science in the Public Interest called for assurances that the genetically engineered goats do not accidentally enter the food supply, saying that “Humans are fallible; accidents happen” (Pollack). Pen Caplan, who headed the original ethical review, referred to the ways manipulating the living world had backfired when he said “Think of Kudzu, or Japanese beetles or the rabbits that went nuts reproducing is Australia” when he commented on the first lab created microbe mentioned before (Flam). The Kudzu, Japanese beetles, and rabbits are invasive species which reek havoc in the land they are introduced to. They overpopulate and harm the native ecosystem. People are worried. Since some animals treated with gene therapy through viral vectors, using viruses to introduce new DNA into an animal body, could the viruses harm the people consuming the animals or their young?
Questions and thoughts like those mentioned before spark much of the controversy between the proponents of genetic engineering and those who oppose it. Although, no questions spark more controversy than ethical questions. People wonder if it is “ethical” to manipulate animal DNA and “play God” like scientists now do everyday. They worry about the quality of life that these lab creations have. Could it be fair to hurt animals for human benefit (Mulrey)? Of course, using genetic engineering, pharmaceuticals can be made, diseases can be cured, and faster growing, healthier produce can be created. These views spark the classic practicality versus ethics debate. This said, there is no correct way to view genetic engineering. It all depends on what you believe is right and what is wrong.
In conclusion, genetic engineering is the process in which recombinant DNA is used to introduce desirable traits into organisms. The DNA is either taken form existing organisms or created in a laboratory. Even fully made artificial DNA sequences is being made by scientists. Genetic engineering is done in animals for many reasons, among these are to produce pharmaceuticals on a greater scale, create more healthful efficiently produced food, and animal resistant to certain diseases and extreme environmental conditions. Animals are regulated strictly by the government to ensure they pose no new risks to humans, animals, and the environment. There is much debate over whether genetic engineering in animals is a good or bad thing, but it really comes down to a fight over practicality versus ethics. Like it or not, genetic engineering is coming, creating the creatures of the future.
Works Cited
Dresen, Cally. E-mail correspondence. 2 Mar. 2011.
“Fact Sheet: Genetically Engineered Animals.” FDA U.S. Food and Drug Administration. FDA U.S. Food and Drug Administration, 28 Oct. 2009.Web. 1 Feb. 2011.
Flam, Faye. “Advance of Horror: the First Lab-Created Organism.” Philadelphia Inquirer.(21 May 2010): A.1. SIRS. Web. 7 Feb. 2011.
“GM mosquitoes deployed to control Asia’s dengue fever”. The Independent: Science. independent.co.uk, 27 Jan. 2011. Web. 7 Feb. 2011.
“General Q&A: The Technology.” FDA U.S. Food and Drug Administration. FDA U.S. Food and Drug Administration, July 1, 2009.Web. 1 Feb. 2011.
“Genetic Engineering.” FDA U.S. Food and Drug Administration. FDA U.S. Food and Drug Administration, 30 April 2009.Web. 1 Feb. 2011.
Kaplan, Karen. “Stem Cell Method Finds Cure.” Los Angeles Times. (7 Dec. 2007). SIRS. Web. 7 Feb. 2011.
Mulrey, Stacy. Personal interview. 4 Mar. 2011.
Pollack, Andrew. “Drug from a Goat With a Human Gene.” New York Times. (7 Feb. 2009): B.1. SIRS. Web. 7 Feb. 2011.