Seeing Double, Feeling Strange
Cloning and Xenotransplantation
Genetic Research Back to Top
Science has been moving ahead in what appears dramatic fashion. Over the last several decades, science has advanced to the level of being able to clone body parts as well as complete animals. In addition, body parts from one species can be transplanted into another. Are these advances we should applaud or are they further examples of how we as humans place ourselves above all other species on this planet? Is it a further indication that we will do anything for science even if nonhuman animals are harmed in the process?
Cloning Back to Top
Cloning involves the creation of genetic replicas of cells, tissues, and organs. According to the Human Genome Project, there are three types of cloning: (1) recombinant DNA technology or DNA cloning, which creates copies of genes or DNA segments; (2) reproductive cloning, which reproduces entire animals; and (3) therapeutic cloning, which creates embryonic stem cells.
When cloning involves reproducing an entire animal, it directly interferes with nature’s way of reproducing that animal and potentially has the capacity of exponentially increasing unwanted animal populations, especially cloning that involves companion animals. While the clone may be a genetic replica of the original, the clone will not be the same as the original. The new animal may vary in appearance, personality, and behavior. Because of its unpredictability, cloning cannot promise what some may hope for—an exact copy of a beloved companion animal.
But reproductive cloning is not just for the well off who want to replicate Fido or Fluffy. Cloning of food production animals is becoming big business and may change the landscape of factory farming. In reproductive cloning, the eggs from the female are taken from her ovaries and the gene-containing nucleus is removed. The nucleus from the animal the breeder wants to copy is added to the egg. Eventually the egg cell begins to form into an embryo which is implanted in the uterus of a surrogate who carries the fetus to term and delivers him or her as if the infant animal were her own offspring. In food production, the cloned animals become the breeding stock and their offspring become the food source.
Cloning is further used in the laboratory to produce specified, made-to-order animals for experimental purposes. As far back as 1952, scientists began cloning animals, the first a tadpole. The most famous cloned animal was Dolly (1996), a sheep who lived for half the normal life expectancy of her breed of sheep, which is typically 12 years.
In addition, attempts have been made to clone endangered and even extinct species. While this may seem a noble pursuit—to reintroduce species that have disappeared from this planet—will there be a place for these animals? These animals may be endangered or extinct because their habitat is being (or already has been) destroyed by direct human intervention (deforestation, for example), climate change, or pollution—any one of which has created an untenable environment for them to live in. Should we be creating animals and then placing them into a new world unfit for them to thrive in just because we can?
Cloning is costly to the animals who are the result of the cloning procedure. Most do not survive. Scientists tried over 275 times before successfully cloning Dolly. And Dolly is not the only animal to be cloned. Among other animals cloned are goats, cows, mice, pigs, cats, and rabbits. Pigs in particular are being cloned for the purpose of harvesting their organs and tissues for human transplantation, known as xenotransplantation.
Xenotransplantation Back to Top
Xenotransplantation is the process of placing live, nonhuman animal cells, tissues, and organs in human patients. It was pioneered a century ago with little success until technology caught up with the concept. Since the 1960s when the concept became popular again, pig hearts, baboon livers, and chimpanzee kidneys have been transplanted into human beings. Other examples of xenotransplantation include using fetal pig cells to treat Parkinsons’ Disease, baboon bone marrow to treat patients with HIV, fetal calf adrenal cells implanted in spinal cords for pain relief in end-stage cancer, and pig pancreatic islets to treat insulin-dependent diabetes mellitus. Some recipients live only days following surgery; others years. The nonhuman animal typically dies or is killed following transplantation.
While baboons and chimpanzees have been used in the past, the animal of choice today is the pig. Pigs are not on the endangered species list as some of our closer relatives in the ape family are; they are quick to mature; and they breed well in captivity, usually producing large litters. In addition, their organs are about the same size as those of a human. But there is another reason pigs are considered the animal of choice for xenotransplantation. We already eat them; why not use their vital organs as well? Animals in the ape family are often seen as being too much our kin for us to want to kill them for their organs. We do not have the same feeling about pigs even though pigs have been shown to be intelligent, loyal, and playful—not unlike one of our more revered companion animals, the dog. In fact, in some instances, they have been found to be more intelligent than our canine companions.
Today, genetically engineered (cloned) pigs are being produced to control many factors that cause xenotransplantations to fail; for example, to cut down on the rate of organ rejection. Another factor is the transmission of porcine viruses to human recipients of pig organs and skin. Since there is a concern of spreading nonhuman animal diseases to humans through xenotransplantation, using genetically engineered animals can cut down on the possibility of transmitting diseases from the donor to the recipient. In addition, if viruses are transplanted, people who are around the recipient of nonhuman animal body parts may be at risk for acquiring the same diseases.
Not all transplants are from nonhuman animal to human animal but may be from one nonhuman animal to another nonhuman animal. By transplanting from one nonhuman animal to another, scientists can determine if their genetically engineered donor produces safe organs to transplant into another animal without risking a human life. But, as always, the donor most often dies as a result of the transplant. Recipients in these transplants are also expendable once they are of no value to their researcher.
Take Action to Reverse Cloning/Xenotransplantation Abuses Back to Top
What can you do to change the trend in cloning animals and using their organs and other body parts for transplantation? First, educate yourself on the subject of cloning and xenotransplantation. Other humane actions include:
- Become an organ donor. The process is easy. Go to organdonor.gov and learn how. One of the reasons cited for cloning animals for their organs is that few people register as organ donors. You may save a human’s life and a nonhuman’s as well if you become an organ donor.
- Insist that cloned food—whether animal- or plant-based—be labeled so you can make an informed decision in the grocery store.
- Lobby your elected officials, urging them to enact legislation that will protect nonhuman animals against the abuses of cloning and xenotransplantation.