Animal Cloning, Medical Potential and Ethical Issues

After the success of Dolly the cloned sheep, germline technology has shown promise in the medical field. However, the ethical controversy of animal cloning, its ecological impact, and the benefits for human treatment need to be discussed.

 

When did interest in cloning begin? Was it when we started wondering how to fix our own organ problems, or when we started looking for something to do the work for us? We don’t know exactly when it started, but the first successful animal cloning was probably the first time the idea of cloning became a reality rather than a sci-fi fantasy. In early 1997, scientist Ian Walmut and his colleagues at the Roslin Institute in Edinburgh successfully created the world’s first cloned animal, Dolly the sheep, using nuclear replacement technology. This was done using nuclear transfer technology. To explain the process of cloning Dolly in simple terms, the nucleus of the adult sheep you want to clone is fused with the egg of another sheep. This fusion is then placed in the uterus of a surrogate sheep. Once the fusion implants, develops, and gives birth, a dolly is created. The process sounds simple, but it’s not. When Dolly was created, only 29 of the 277 fusions implanted in the uterus developed into embryos, and only one continued to develop until birth. As the news of the successful cloning of a sheep spread around the world, Dolly the sheep and nuclear transfer technology became the center of attention around the world.
Nuclear transfer technology can be used for other purposes besides cloning. For example, there is a genetic disease in which the bone marrow lacks certain immune proteins. By extracting hematopoietic stem cells from a person with this disease, replacing the nucleus of the cells with the nucleus of a normal person without the disease, and putting them back into the bone marrow, the cells are able to produce specific immune proteins and carry out normal immune activity. In addition, before creating a cloned animal, such as Dolly, DNA can be inserted or replaced in the nucleus of the somatic cells of the animal to be cloned and fused with an egg to create an animal that is not just cloned, but has the desired improvement.
There is still a lot of fear and much more opposition to using nuclear transfer technology in humans because the risks are too high. Ethically, human cloning should not be practiced, so much so that UNESCO, in its Universal Declaration on the Human Genome and Human Rights, declares that “acts against human dignity, such as reproductive cloning of humans, will not be permitted.” However, when it comes to people’s reactions to the use of SRT in animals, there is no clear-cut majority in favor or against. Some of the arguments for and against include that genetic diversity will decrease because the DNA will be altered so that only the good genes will remain, and that humans have no right to make animals suffer. Proponents argue that cloning multiple copies of the same animal would make it easier to test new drugs, and that it would allow for organ transplants and the production of more biomaterial. At the current level of medical science, it is essential to make animals suffer in order to obtain the desired substances through experiments. It’s also true that the use of nuclear replacement technology on animals is beneficial to medicine. It is reasonable to argue that just as humans do not have the right to cause other humans to suffer, animals do not have the right to do so either. However, due to the limitations of our current state of medical science, I’m in favor of using ESRT on animals for medical purposes.
First, as mentioned above, we can make more of the substances needed to treat people. Pig organs are very similar to human organs. If pig organs could be transplanted into humans, fewer people would die waiting for a transplant. As the number of organs increases, the cost of providing them will naturally decrease. More than 160,000 people a year die because they don’t have a suitable organ. Making pig organs transplantable could save 160,000 lives a year. Making pig organs transplantable into humans requires nuclear replacement technology. The human body has an immune response to anything that doesn’t belong to it. No matter how similar an organ from another species is, the immune response will trigger the transplant and destroy the transplanted organ, preventing it from functioning properly. By using nuclear replacement technology to make the genes of another species (e.g., pigs) resistant to human immune response and obtaining organs from that species, we have organs that can be transplanted into humans. Organs aren’t the only material that can be obtained from animals. Specialized proteins needed for treatment can also be obtained from transgenic animals. Hemophilia is a hereditary mutation that causes a lack of clotting factors in the blood, so when a normal person bleeds from a wound, it stops and a scab forms, but people with hemophilia continue to bleed because their blood doesn’t clot. The treatment for hemophilia requires clotting factor IX. Imagine that this clotting factor can only be obtained from humans: blood donations are not enough to cover the blood needed for transfusions, so blood is imported, and there is still a shortage of blood, and it is unlikely that enough clotting factor will be available for treatment. However, if we use nuclear replacement technology to replace the human gene for clotting factors with the gene for clotting factors in milk-producing animals such as sheep and cows, we can produce milk containing clotting factors.
Second, it allows for more precise testing. When testing new drugs in humans, we usually use rabbits, which have similar immune systems to humans. But just as each person will react differently to a drug, there will be clear differences between each rabbit, so when measuring things like the right dose of a drug, you’ll get more accurate results if you use exactly the same rabbit. Exactly the same rabbits don’t exist in nature. However, by cloning a single rabbit using nuclear replacement technology, you can get multiple rabbits that are exactly the same, which can lead to more accurate results. Another great thing about experimenting with cloned animals is that you can use fewer animals than you would if you were experimenting with non-exactly identical animals.
Finally, it’s less damaging to the ecosystem. We’re not talking about animals that you grow yourself, but animals that are captured from the wild and used in experiments. A good example is the horseshoe crab. The blood of horseshoe crabs is blue, which is not the color we’re used to seeing. This is because their blood contains hemoglobin, which gives off red light, and hemocyanin, which is a copper-based compound that gives off blue light. This blue blood is used in endotoxin tests to determine the level of toxicity that is safe to administer to patients. By isolating transformed cells from the horseshoe crab’s blood and seeing how much it clots, it is possible to determine how much venom it contains. To test this blood clotting, 500,000 horseshoe crabs are taken from the sea each year and 30% of their blood is taken and returned to the sea. However, 10% of the horseshoe crabs die during the blood collection process, and not all of the horseshoe crabs that are returned to the sea survive. It’s a contradiction to think that a horseshoe crab can live again without consequences when 30% of its blood is taken out. For this reason, horseshoe crabs have become a critically endangered species, and the other organisms that feed on them have declined accordingly. If, instead of harvesting horseshoe crabs from the ecosystem, we extracted their nuclei and eggs and then artificially fertilized and cloned them, we would have enough horseshoe crab blood for our experiments without reducing the number of horseshoe crabs needed to maintain the balance of the original ecosystem. If we could further manipulate the horseshoe crab’s genes to make it produce more blood in the first place, or to make it more resistant to the stress of being drawn, or to recover more quickly from being drawn, we could further reduce the damage to the horseshoe crab.
Even with these gains, those who oppose the use of nuclear replacement technology on animals for medical purposes will still talk about the sacrifice of animals. But can we really prioritize animals over people when our species is human? When it comes to animal testing for people we have no connection to and will never meet, and the animals suffer as a result, we may be more inclined to consider their suffering and oppose animal testing. But can you prioritize animals when it’s your family or yourself? An animal’s life is not worth less than a human’s, but if they are equal in weight, it is only natural that we would weigh in favor of the one that is more precious to the individual. If vaccines, organs, and immunizations that come from the suffering of animals are the only way to save your family, friends, or yourself, then I think you have to accept that as a choice. Also, if you think about it, nuclear replacement is one of the ways to reduce the suffering of animals in animal testing. Let’s take the pig example I mentioned in my first argument. Many people can be saved with organs from pigs, but as many pigs will die as there are organs to be saved. If we use nuclear replacement technology to create mutant pigs to transplant organs into humans, for example, pigs that have four or more kidneys instead of two like normal pigs, we can reduce the number of pigs that die. Also, as mentioned in the first and third arguments, nuclear transgenesis is a way to reduce the suffering and death of animals used in experiments by making it possible to obtain medical materials from non-living materials.
Based on the above arguments, I am in favor of the use of transgenics in animals for medical purposes and in experiments. However, this is not an unconditional endorsement. I prioritize human suffering over animal suffering, but I don’t believe that animal suffering is necessary for human benefit. We should think about animals as much as we think about the benefits we gain from their sacrifice. While we can’t completely eliminate animal testing with our current technology, we shouldn’t take it for granted, but we should advance our technology in a way that is consistent with the 3Rs of animal testing: as few as possible, no substitutes, and no pain. Examples include the development of adult stem cell research, which allows single cells to differentiate into organs, and the development of sophisticated analyzers that can test for endotoxins instead of horseshoe crab blood. While we still test on animals because the technology is less advanced, we shouldn’t use “not yet” as an excuse to continue testing on animals. We must continue to advance technology for animals, by animals.