Transgenic animals are creatures who have had their genome altered because of the transfer of a gene or genes from another breed or species. This process is used routinely in laboratory models as part of the biomedical research process. 95% of the animals who fall into this category are rodents, with most of them being mice. Researchers use this method of research to understand human disease better, look at gene functionality with regards to disease susceptibility, and determine the necessary response for a therapeutic intervention.
The most common transgenic animals that you will see in the world today are mice that have received genetic modifications so that they naturally produce human antibodies. Out of the 11 monoclonal antibody drugs approved by the Food and Drug Administration from 2006-2011, 7 of them were derived through the use of transgenic mice.
We are also exploring this science to see if livestock and farm animals could produce complex human proteins that would provide benefits in the treatment of human disease. We currently produce them in cell-based reactors, but it is a process that is exceptionally expensive. A single mammalian-based reactor was estimated to cost $500 million in 2008.
The pros and cons of transgenic animals often try to balance the ethics of treating an animal appropriately with the potential benefits that the research can produce.
List of the Pros of Transgenic Animals
1. This science allows us to create specific economic traits through animal products.
Some transgenic animals are produced for their specific economic traits. Cattle can produce milk that contains particular proteins which could help in the treatment of emphysema. We use antibodies from mice and other rodents to create new medical therapies that can reduce or eliminate the impact of illness and disease. Harvard scientists received a U.S. patent for a genetically-engineered mouse that carries a gene which promotes the development of human cancer so it can be studied more effectively.
2. There are three different methods available to use to create transgenic animals.
Researchers can take advantage of three common methods of producing transgenic animals for their research. Genes can be transferred to the animal through DNA micro-injection, by using a retrovirus-mediated transfer process, or to do so through embryonic stem cell transfers. Most facilities still use the first method, and then the transgenic animals are mated to ensure that their offspring acquire the desired genetic profile. This advantage allows for the traits to become part of the animals’ standard genome over just a generation or two.
3. It allows us to research human diseases more effectively.
Transgenic animals make it possible for scientists to study the functioning of particular genes at the level of the entire organism. This process enhances the study of physiology in a number of fields in addition to the benefits achieve in disease biology. New targeted drugs have come from this work, but the similarity in function and physiology between humans and rodents makes it easier for the laboratory to use this technology and process to mimic human disease.
Transgenic mice are currently being used as models to study heart disease, arthritis, anxiety, Alzheimer’s disease, diabetes, aging, and Parkinson’s disease. We can also glean new insights into how cancer forms with this process.
4. We could potentially solve our organ transplant list crisis.
There are currently more than 114,000 people on the waiting list for a life-saving organ transplant in the United States right now. Thousands more are on lists all over the world. Another name is added to it in the U.S. lists every 10 minutes on average. About 20 people die each day because there is a lack of organ availability. Transgenic pigs could help to solve this problem. Researchers are looking at these animals as a potential source for organs to transplant, which would allow us to reduce severe donor shortages.
5. This technology can help us to create life-saving medicines already.
We are already using transgenic technologies as a way to create insulin and other maintenance medications that are challenging to synthesize otherwise. Animals who have their genes manipulated can help to produce more of the vaccines that are necessary to reduce the threat of serious communicable diseases. Blood clotting factors are possible with this advantage as well. Transgeneis makes it possible to save lives proactively because we are using natural methods of product creation.
6. It gives us a way to create healthy additives for our food supply.
Lactoferrin is a protein that is found in human breastmilk and bovine milk. The colostrum that comes immediately after a baby is born contains significant amounts of it. You can also find it in the fluids of the intestine, nose, respiratory tract, and even in your eye. When it is used as a medicine, it can treat stomach ulcers, intestinal problems, diarrhea, and even hepatitis C. It functions as an antioxidant too, which means it can help to protect against viral and bacterial infections. It even stimulates the immune system.
Transgenic cattle who can produce milk with higher quantities of lactoferrin can create robust supplies that are useful in numerous industries. Even industrial agriculturalists use it to kill bacteria during their meat processing work.
7. Transgenesis can produce animals which are stronger and healthier.
Although the success rate for artificial breeding is low when looking at the transgenic technologies today, scientists can naturally breed the animals that come from their work. When both parents have the same manipulated traits, then the odds of having it pass along to the next generation are exceptionally high. We can begin to build a healthy and helpful generation of animals from a variety of species that are productive, useful, and healthy without being abusive to them.
8. It can reduce the environmental impact of the animals.
Commercial farming over the past generation has seen numerous criticisms over the number of adverse environmental impacts that occur from their processes. The production of transgenic livestock brings with it the potential to dramatically reduce the footprint of this agricultural economic force without limiting its value. Transgenesis could increase efficiencies while reducing the amount of water and land resources needed to support large herds. It could even work to protect the groundwater and soil.
Pigs do not utilize phosphorus well, so they require continuous supplements to ensure proper health. Not only does this increase production costs, but it can also change the composition of the soil. Transgenesis could change the genes which turn off absorption for the swine so that farmers see lower costs, higher yields, and improved land resources simultaneously.
9. Transgenic animals can improve the quality of our food supply.
We might use transgenic animals as a way to improve access to medicines and research, but this technology is also useful in the creation of better food products. Enhanced milk is a common option considered with this benefit. The three primary nutrients that are in this fluid are lactose, fat, and protein. By elevating or decreasing them, we can impact the health and growth of animal offspring while improving the items on store shelves as well. All it takes is an improvement in milk yields of as little as 2L per day to have an immediate impact on the weaning weight of cattle.
10. This technology improves disease resistance for the animals too.
Genetic modification of livestock can enhance animal welfare because it creates the potential of having a healthier animal. The agriculture industry places the welfare of livestock as a high priority because the loss of single individual can mean several thousands in lost profits. The application of transgenesis methodologies will provide opportunities to create a superior level of disease resistance. Whether there is a need to treat mastitis, manage hoof rot, or improve the overall performance of the animal, this technology can make good things happen.
11. Transgenesis can improve the quality of non-food animal products.
The quality, yield, and color of the fiber, wool, and hair that we use that gets harvested from animals has long been a focus of the transgenic animal industry. By manipulating the length, strength, and crimp of the wool, there could be an increase in the availability of fibers without impacting the overall cost to the consumer. By decreasing the surface interaction of each fiber, it may become possible to decrease shrinkage in the apparel made from these fibers as well.
12. We can use this technology to create better agricultural products from other animals.
One of the most novel approaches that scientists have created through transgenic animals is an improvement to the production of spider silk. This useful fiber uses the milk of transgenic goats. Instead of waiting for orb-producing spiders to weave a web, the technology allows for the synthesizing of up to 7 different types of silk. The Dragline variety is the most coveted as it can be elongated by up to 35%, offers robust tensile properties that are equitable to Kevalr™, and it offers an energy-absorbing capability that is stronger than even steel.
List of the Cons of Transgenic Animals
1. There are numerous ethical concerns to review when using transgenic animals.
We must take a look at the decision-making processes from an ethical standpoint to determine if the creation of transgenic animals is the right choice to make. Although some people will take an “ends justifies the means” approach to this situation, we must at least look at the various processes involved to determine if there should be a universal protocol that researchers follow. Then we must ask if human welfare is the only consideration in the evaluation process. Do we need to focus on cultured methods instead of using live animals?
2. It creates the potential for economic harm due to the patenting process.
The creation of the OncoMouse® was a significant breakthrough for research science, but it also set a dangerous precedent from a patenting standpoint. When companies can protect their research in this manner while manipulating the genome of animals, then the motivation becomes more about the potential for profits than it does for human welfare. That makes it a challenge to present an ethical defense because you’re exploiting live animals to create a healthier profit margin.
We butcher animals all of the time as a food resource, but the argument that killing an animal is no better than harming one is a false equivalence. Using live creatures to exploit others sets the stage where only the wealthy can gain access to this new technology.
3. The reliability of transgenic technologies is questionable.
The success rates of creating transgenic animals using DNA micro-injection are extremely low, even though this method is the most popular one used by researchers today. Only 0.6% of transgenic pigs were born with a desired gene after workers injected over 7,000 eggs with a specific transgene. That means we are introducing a lot of waste into the system where the animals may not even have a chance to live.
4. There is no consistency to the patenting process in this industry.
The Supreme Court of Canada ruled in 2002 that higher life forms are not eligible for patenting because they were not a composition or manufacture of matter within the meaning of an invention in accordance to the Patent Act. The United States issued a patent for the OncoMouse without question, which is No. 4,736,866, although it is notable that the claim explicitly excludes humans. Europe approved this patent eventually because the usefulness of cancer research satisfied the likelihood of a substantial medical benefit, but rejected the Upjohn mouse because the gene only caused the animals to lose their hair.
In the 1992 Upjohn case, the pharmaceutical company wanted to test products that could increase wool production and treat human baldness. The European Patent Office decided in this situation that the harm to the animals outweighed the benefits that society would receive from the work. The reality is that there is no consistency across nations as to how we should commercially treat transgenic animals.
5. It might be dangerous to eat transgenic animals.
One of the advantages that transgenic technology supporters often point out is that this work can create healthier animals who can provide us with a better nutritional profile. Americans and Europeans are sharply divided on this subject. The application of gene modification technologies is strictly regulated for domestic and imported goods. Providers must follow the legal frameworks in place before they can even start the process of working with transgenic animals. No GM animals or derived products are on the market in Europe, but they could be in the United States.
No documented cases of harm have been documented from a clinical standpoint to justify the concerns of allergies or illness from genetically modified foods. We also have no data on how the long-term health of individuals could be affected by consuming these items regularly.
6. Transgensis could result in the unregulated expression of genes.
Although scientists feel like they have a handle on the processes necessary to create transgenic animals and breed new generations of them, there is always the risk that this technology could create unregulated expressions that could over- or under-produce the wanted products from this effort. Having too much of the wanted item might seem to be a nice problem to have, but it can also impact the lifespan of the animal.
Cows have a natural lifespan of approximately 20 years. Some species can produce milk for eight or nine years. The stresses of constantly producing a food supply, coupled with factors that include lameness or disease, can shorten that time by up to 50%. It is not unusual for the dairy industry to send cows for slaughter (even transgenic animals) before they reach the age of 5.
7. It comes with the possibility of side effects for some of the animals.
There are numerous potential side effects that transgenic animals might experience after they receive gene manipulation treatments. Even if this process occurs in the womb, evidence from transgenic swine showed that the animals were more prone to developing arthritis, had changes to their skeletal growth, suffered from dermatitis and gastric ulcers, along with an increase in renal disease and cardiomegaly. When these problems occur in the genetic profile of the animal, then it becomes a waste of resources for everyone involved in the development process.
8. Transgenesis can result in a higher level of genetic mutations.
One of the most significant risks of transgenesis technologies is the risk of an insertional mutation occurring. This problem occurs when a DNA fragment goes into an essential gene for the animal. It can result in numerous biological processes being altered in ways that are not beneficial to the animal or the work being done. Mosaicism is also possible because of this technology, since there is always the possibility that only a small portion of the cells will actually incorporate into the transferred gene.
Researchers have also discovered that there are times when the transgene integration process only occurs on the Y chromosome. When this issue happens, then the desired traits will only transfer through the males of the species. Most of the issues are related to the actual transgene, the integration site, or its expression and can be addressed, but there are still unpredictable factors to review as well.
Transgenic animals pose numerous questions for our approach to bioethics in general. There are also specific questions to ask in the context of national patent systems with regards to the ethics of issuing a financial reward over a living creature. Different jurisdictions are dealing with the basic questions that this technology creates in unique ways. Should the specific changes to a genome be worthy of consideration as being patentable subject matter?
The results of transgenic animal research are beginning to accumulate, and what is available is so far impressive. Numerous medications are in various stages of study right now because of this technology that wouldn’t have been available otherwise.
The pros and cons of transgenic animals are key points that we must all consider as we evaluate the creation of new medicines and research opportunities at the expense of the animal kingdom. How we treat those who need our help is a reflection of who we are as a population. If we are willing to harm mice to create the potential for human gains, then that says more about who we are as a society than it does about the actual technologies.
Natalie Regoli is a child of God, devoted wife, and mother of two boys. She has a Master's Degree in Law from The University of Texas. Natalie has been published in several national journals and has been practicing law for 18 years.