In the scientific world, there are many ideas which might not be met with open arms. This is especially true when it comes to embryo experiments, as that remains a morally gray area, for the time being. In Japan, however, the first human-animal embryo experiments will commence. While there are a lot of benefits, the drawbacks should not be overlooked either.

The Concept of Human-Animal Embryos

Whereas some people might think these experiments will yield human-animal hybrids, that is not the case whatsoever. It is certainly true scientists will experiment with animal embryos containing human cells, but their purpose for doing so is vastly different. The main objective is to address some key problems in the medical industry, including the shortage of

In Japan, the focus will now shift to transplanting these hybrid embryos into surrogate animals and observe the results. One stem-cell scientist has officially received the blessing and backing of the domestic government to explore this new field of study. That comes as a bit of a surprise, considering this practice was banned in Japan until rather recently. 

The current plan of action is to grow human cells in embryos of mice and rats. Once successfully combined, the embryos will be transplanted into surrogate animals in the hopes of creating suitable organs for human transplantation purposes. Only time will tell if such a venture can be successful, as animals and humans are very different from one another in terms of biology.

It is not the first time human-animal embryos are created in a controlled environment either. In the United States, this practice is not uncommon, although none of the embryos have ever existed for more than two weeks. Moreover, there has been no further funding of this scientific research in the US since 2015, further dissuading scientists from experimenting in this regard. 

Taking a slow and steady approach while growing these human-animal embryos is the only viable course of action. The scientist in question confirms he will grow hybrid embryos at a controlled rate by focusing on mice first. Once deemed successful, the same experiments will be conducted with rats. Later on, he aims to receive governmental approval to grow such embryos in pigs, although it remains to be seen if that request will be granted when push comes to shove.

As one would expect, this field of study draws a lot of ethical concerns. Purposefully ‘playing God” with human-animal embryos is not something that should be treated lightly. There is also genuine concern as to how human cells would affect the cognition of the surrogate animal over time. If human cells travel into the animal’s brain, no one knows for sure what the consequences could be. Despite trying to target very specific regions of the body, no one knows for sure if things will go according to plan.