In a very controversial move, the first pig-human hybrid has been created in a lab. Researchers were successfully able to grow human cells inside early-stage pig embryos, which lead to the creation of the first pig-human hybrids. This kind of hybrid is known as an interspecies chimera.
The experiment is still in its early stage; however, scientists believe that the “breakthrough” could one day guide us towards lab-grown human organs that could be transplanted into people who need them. If successful, there might be a revolution in healthcare and saving a lot of lives.
In the experiment, US scientists injected human stem cells(HSC) into early-stage pig embryos. The hybrid embryos formed, were then implanted into surrogate sows. The researchers waited until the embryos developed into the first trimester.
Finally, more than 150 of the embryos developed into chimeras. Each embryo had formed the precursors of various organs, including the heart and liver. They also contained a small amount of human cells — approximately 1 in 10,000 of the hybrid cells was human.
Juan Carlos Izpisua Belmonte, from the Salk Institute in California who also worked in the team said: “Our findings may offer hope for advancing science and medicine by providing an unprecedented ability to study early embryo development and organ formation, as well as a potential new avenue for medical therapies.”
He further said, “We have shown that a precisely targeted technology can allow an organism from one species to produce a specific organ composed of cells from another species.”
However, reactions to the new experiment have been quite mixed; one can see that science has taken a long jump to the future now that the first human-pig hybrid has been created. But, the ethical implications and concerns have to be dealt with.
In 2015, Izpisua Belmonte and his colleagues performed various experiments to create interspecies chimeras in the lab. The team had successfully integrated human stem cells into mouse embryos, displaying those human stem cells could develop inside other species. They successfully created world’s first chimera.
The word chimera originates from Greek mythology. According to the legend, there was a monstrous, fire-breathing hybrid creature of Lycia in Asia Minor. It was composed of the parts of various animals. Very often, it was depicted as a lion having a goat’s head sticking from the side of its neck, and a snake for a tail. However, biology describes the chimera as a natural or artificial development of individual organisms having cells from another as well. For obvious reasons, scientists are totally fascinated by chimeras.
According to scientific reports, there are two ways to make a chimera. The first method is to introduce the organs of one animal into another. This has high risks, as the host’s immune system may consider it foreign, attacking it and causing the organ to be rejected. While,the other method is to introduce one animal’s cells into the embryo of another at the embryonic level and implanted to grow into a hybrid. This can be done deliberately in a lab, or can happen even accidentally — such as the time a man failed his paternity test because he absorbed his twin in the womb.
Regarding the pig-human hybrid, Belmonte stated, “The ultimate goal of chimeric research is to learn whether we can use stem-cell and gene-editing technologies to generate genetically-matched human tissues and organs, and we are very optimistic that continued work will lead to eventual success.” He added, “But in the process we are gaining a better understanding of species evolution as well as human embryogenesis and disease that is difficult to get in other ways.”
Those hybrid embryos for the pig-human hybrid experiment were aborted after 28 days of development to avoid further ethical concerns. Debate on the ethics is expected to be on fire, as the National Institutes of Health (NIH) had previously issued a moratorium on experimentation on human chimera, but is now considering reversing the ban.
Many supporters of the research argue that the experimentation is justified, because 22 deaths happen every day in the United States waiting for an organ transplant and someone new is added to a donor list every 10 minutes.
The team’s work was published in Cell. In the video below, they discuss their results: