Scientist are racing to create Chimeras, but are they moving too quickly?
When the word chimera comes up in conversation, some envision snarled creatures that crawled out of Fullmetal Alchemist. Hybrids of human and animal, they defy the laws of nature and raise questions about humanity. The Greeks depicted the chimera as a monstrous creature with a lion’s body, a serpent-like tail, and the head of a goat emerging from between its shoulder blades. The existence of such an animal may scream conspiracy, but it is not. Chimeras live among us. Science is propelling the development of these beings to a realm of fascination and disbelief.
What is a Chimera?
The real definition of a chimera is a single organism blended with multiple sets of DNA. Occurrences of Chimeras in nature are rare, but happen. Taylor Muhl is a human Chimera who absorbed her fraternal twin in the womb. This absorption caused Taylor to have two immune systems, two bloodstreams, dual skin tones on her abdomen, and two sets of DNA. Taylor is not the strangest example. Science has and continues to produce the most fascinating chimeras yet.
A Chimera Virus
The Chimera Virus is not a virus created to destroy chimera. Instead, it is one. In 2017 Portuguese scientists collaborated with Harvard-Medical school to create a chimera virus by introducing the human viral gene for herpes into a similar mouse virus. The result of their experiment was the inhibition of the human herpes virus.
The Human-Pig Chimera
In 2017 a team of California scientists created a Chimera by injecting the early-stage embryo of a pig, with human cells. The tracked growth of the embryo was to four weeks of development. The experiment was not as successful as the scientists were hoping, though it did serve a purpose. The research proves that a non-human organism introduced to human cells can develop within a host animal. The level of success of the experiment was enough to motivate the scientific community.
The Human-Mouse Chimera
In March of 2019, Japan caused a stir by reversing a long-standing restriction on using animal embryos to grow human cells. A stem-cell biologist at Stanford, Hiromitsu Nakuchi is more than delighted and ready to work. Nakuchi plans to begin his experiments by introducing human pancreatic cells into the embryos of mice and rats.
In 2019 scientists in China claimed that they have successfully created an embryo, which is a combination of monkey and human DNA. Juan Carlos Izpisua, the biologist leading the experiment, is also the head of a lab in California. The close relationship between humans and primates has led to mass controversy on the topic of combining genetics.
The scientific reason behind creating chimeras with human DNA is to progressively move towards a future where these animals are capable of growing human organs. The human organs grown inside of these chimeras are for human patients who require transplants. By using the stem cells harvested from the person needing the operation, scientists believe that they will be able to create organs that can be customized to an individual patient’s biology. Customizing the organ for the patient would solve the problem of organ rejection, as well as address the lack of available donor organs. There is also the fight against viruses that come into play. The Chimera virus may play a vital role in determining the future of viral research.
Many ethical controversies come with using embryos for science. Using animals for experiments is one point of contention. Some fear that human cells will migrate to the animal’s brains, and cause a conscious awareness that they otherwise lack. In the case of human-monkey chimeras, because primates are so closely related to us, the fear is even greater. The image of intelligent monkeys running the world is one that most of us can easily conjure.
The Future of Chimeras
Since the study and development of chimeras in a lab is relatively new in scientific terms, the future leaves room for the imagination to run wild. Changes in regulations and laws will determine the critical factor in whether or not research will continue moving forward. The world will undoubtedly be watching Japan, and the progress Nakuchi makes in the coming months.
Contributor | Sarah Marlow, editing Maria Mocerino