Diving Into the Realm of Human-Animal Embryos

Informative Article


Human-animal hybrids sound like they can only exist in sci-fi movies, but scientists in Japan have recently delved into this unforeseen realm. Do the ethical concerns outweigh the scientific benefits?


by Thejo Akkoor

According to Greek mythology, a chimera is ‘a fire-breathing female monster with a lion’s head, a goat’s body, and a serpent’s tail’. These animals couldn’t possibly exist in the real world, right? Well, a chimera in biological terms is an organism containing cells from two or more different species. In March of 2020, Hiromitsu Nakauchi, a stem-cell biologist at Stanford University and the University of Tokyo, was given permission from the Japanese government to pursue experimentation into human-animal embryos. However, many believe that suggesting the cross between human and animal organisms may be going too far.


Many countries have imposed restrictions on the pursuit of human-animal embryos, but Japan has recently lifted its ban which was inflicted in 2014. The country has made it legal to insert hybrid embryos into surrogate animals and bring them to term. Nature.com states that Nakauchi doesn’t expect to create embryos immediately, but hopes to continually advance their research. They have previously experimented by transplanting mouse cells from a mouse genetically engineered with diabetes into a rat without a pancreas. The rat was able to grow a pancreas made entirely of mouse cells, and once the pancreas was transplanted into the mouse, it was able to produce the correct amount of blood sugar. Like this, stem-cell biologists hope to eventually put human cells into animals—like pigs and sheep—to create organs that can be transplanted into those in need of organ donors.


Here is where the Trilemma is presented: Do the ethical concerns outweigh the scientific benefits? One side supports the creation of human-animal embryos, while the other side puts up a strong opposition. Can we find a healthy balance between the two?


For human-animal embryos


As of September 2020, 109,000 men, women, and children in the US are on the national organ transplant waiting list, according to the US Government Organ Donation Statistics. Many scientific and research endeavors in the past have delved deeply into the idea of creating more organs for people in need of donors as an average of 17 die each day waiting for an organ transplant. Thanks to stem-cell research, there is now a possible solution to this severe problem: human-animal embryos.


Hiromitsu Nakauchi has a solution in his hands that could possibly alter the science world as we know it, and there’s no way he’ll rush into it. Scientific American states that science-policy researcher from Hokkaido University in Sapporo, Japan Tetsuya Ishii says, “It is good to proceed stepwise with caution, which will make it possible to have a dialogue with the public, which is feeling anxious and has concerns”. Nakauchi himself plans to take his research slowly so that others can get accustomed to the idea of human-animal embryos. He will also do this to make sure nothing goes wrong; if something does by chance go awry, he plans to suspend the experiment immediately. According to the website Science Alert, Nakauchi himself has said that if they detect more that 30% of the human brain in their research, they will stop all research right away. Nakauchi and his team are trying very hard to make sure that the cells don’t stray from the targeted organ.


In addition to possibly creating organs, this discovery can lead to a newer, deeper understanding of human diseases, and find new ways of treating illnesses.


Against human-animal embryos


When thinking about a human-animal hybrid, many feel that the exploration of such a realm should only exist in sci-fi movies. On the topic of human-animal hybrids, Canadian Queen’s University research chair Douglas Munoz told the Canadian National Post that “[human-animal hybrids] really ethically scares me. For us to start to manipulate life functions in this kind of way without fully knowing how to turn it off, or stop it if something goes awry”. This is the basis of concern for many bioethicists. They believe that the boundaries between human and animal are now blurred, and these are the lines used to justify animal experimentation in the first place. We need to reconcile the traditional views of animals by humanity before taking positions on extreme ethical issues.


One major fear has to do with the human cells in the animal integrating into more than just the targeted organs. This could lead to the subject developing into something completely unexpected, affecting the animal’s cognition. Creating something this unpredictable and new is something that concerns many. Regardless of the efforts to keep the cells in the targeted organ, one can never be completely sure what will end up happening. Thus, it is better not to take such a risk.


There are also risks associated with the lives of the animals used to create organs. After the transplantation, what will become of them? Where will they go? These questions are still yet to be answered.