In August, 2016, the National Institutes of Health announced that it was lifting its ban on research that introduces stem cells from humans into animal embryos. Stem cells have the ability to evolve into any human cell and can grow into any human tissue.

 

The goal of this type of research is to grow human tissues and eventually human replacement organs in animals.

 

What an innovative way to improve upon transplantation medicine! But to realize this potential, we would create an organism that is part animal and part human!

 

These hybrids are the stuff of ancient mythology. These mixtures of different animals are called chimeras after the mythical ancient Greek creature that was part lion, snake and goat.

 

If you think that such a thing could never happen, just consider ten examples of creatures that are already being created by science:

1. Genetically modified cattle with human DNA

2. Rats with human kidneys

3. Human-mouse hybrids with freakishly large brains

4. Humanized milk-producing goats

5. Mice with human anal sphincters

6. Rabbit Eggs with Human Cells

7. Pigs with Human Blood

8. Sheep with Human Livers

9. Cow Eggs with Human Cells

10. Cat-Human Hybrid Proteins

One goal of today's research is to produce tissues and organs for experimentation that will improve our understanding of human disease.

 

An alternative and longer term goal would be to produce organs directly for human transplantation. Imagine an infinite source of human organs - one wears out and you produce a new one as a replacement.

 

While this all sounds great, when you really think about it there are some potentially problematic issues to consider. Stem cells have the ability to form any tissue. So an animal embryo injected with human stem cells could produce an animal with a human kidney or lung.

 

They could then be sacrificed for the human organs that they harbor. At the least, that would be disturbing.

 

However, that would be incredibly useful for medicine and improve the human condition.

• But what about animals where the human stem cells become part of the brain?

• Could we produce some animals that are capable of human thought?

The potential for this now seems possible - wow!

 

But, as arguably the most important human organ and the one we know the least about, these hybrids may also represent a fantastic new frontier for brain research.

 

Maybe some aspects of what was described on the Island of Dr. Moreau are not as fantastic as everyone thought. Some of this can be controlled by timing the introduction of the human stems cells into the developing animal embryo.

 

Knowing the timing of organ development during embryo growth in animals allows scientists some control of what human organs develop.

 

We have a lot to learn about this new horizon in biomedical research. Scientists will need guidance from ethicists and the public as this research begins to develop.

 

It is not yet time to turn your backyard into a hybrid livestock ranch for human organs!

 

 

 

Additional Information:

• Next Steps on Research Using Animal Embryos Containing Human Cells

• NIH considering restarting funding for human-animal chimera research

• Human Chimera Research’s Huge (and Thorny) Potential