The Japanese government has for the first time approved a plan which will allow scientists to create “humanimals,” or animal embryos injected with human cells. This development could lead to what would be called a human-animal chimera, although this approach will be used purely for scientific research.
As Nature reported, a committee from Japan’s Ministry of Science approved a request from scientists who wanted to grow a human pancreas inside rats or mice. Such an experiment has received its first approval since the government ban was removed earlier this year. Approval for experiments of this kind is preconditioned in a way that no ambiguous creature with human properties will be born. Scientists say there are no concerns about that.
“Finally, we are in a position to start serious studies in this field after 10 years of preparation,” lead researcher Hiromitsu Nakauchi told the Japanese newspaper Asahi Shimbun.
This is not the first attempt to create humanimals, however. The same scientists already succeeded in creating human-animal embryos in sheep and pigs last year. The animals were injected with human cells during the embryo cells. However, those pregnancies failed to continue to develop after a few days or weeks. This new experiment aims to bring the pregnancies into a late and healthy stage in which healthy, living humanimals could be born.
Given that the experiment originates from Japan and sees the creation of a living chimera, many suggest that this is a step toward cat-like humans known in Japanese as “Nekos.” However, the experiment will be used solely for scientific and medical purposes.
“At that level, an animal with a human face will never be born,” Nakauchi said.
Instead, scientists hope to provide a reliable and healthy source for human organs so that the enormous wait times can be reduced. If they are successful, patients could continue living their lives with a healthy liver, heart or kidney, because humans and pigs have similar organ infrastructures. However, the experiment implies a number of ethical questions and even hints at animal cruelty. To address those concerns, the team plans to engineer rodent embryos that can’t grow their own pancreas and then inject human stem cells so that the embryos will develop a human pancreas.
However, animal cruelty is not the only ethical issue bioethicists and scientists on the team are facing. Some fear the human cells could find a way to develop beyond the targeted organ and find their way into the animal’s brain and affect its development. This could affect the animal’s cognition and rise a lot of concerns. However, Nakauchi told Nature that this possibility has already been taken into consideration and that they’ll take all precautions.
“We are trying to do targeted organ generation, so the cells go only to the pancreas,” he told the publication.