Just Because We Can? The Chimera Question

June 7, 2016

Without a doubt, the advent of gene editing through CRISPR technology is a scientific and ethical game changer. The potential now to ‘edit’ an embryo has created all sorts of questions that science and governments are grappling with.

But another issue at the forefront now is whether we should edit the genes of another species for our own benefit. Researchers at the University of California, Davis have injected human stem cells into pig DNA and allowed the embryos to mature for 28 days, before terminating the embryos and analysing the tissue. Based on what they’ve found so far, it appears a human organ could be grown to maturity inside a pig and harvested as part of the solution to a shortage of organs for human transplants.

Speculating further, it’s thought that the DNA of the patient in need of an organ could be incorporated into the mix, eliminating the necessity for lifelong immunosuppressant drugs. The first experiments have focused on creating a pancreas, but researchers want to also create hearts, livers, kidneys, lungs and corneas.

So here we have two animal species and want to combine them for the benefit of one, the human. Is growing organs in other animals safe for humans? That is currently being debated, as we have seen the unintended consequences on several occasions of retroviruses being transferred to humans through vaccine development.

But it appears we have learned how to get around that issue. Researchers from Harvard Medical School revealed last year that it was possible to use gene-editing technology to inactivate more than 60 retrovirus genes in pigs in a step towards eliminating any cross species infections. Prof George Church told the BBC: “It opens up the possibility of not just transplantation from pigs to humans but the whole idea that a pig organ is perfectible. Gene editing could ensure the organs are very clean, available on demand and healthy, so they could be superior to human donor organs.”

So should we start growing genetically engineered pigs for the sole practice of destroying them for the organs we’ve created? Numerous studies have been done suggesting that pigs, like most other mammals, have the capacity to not only experience a wide range of recognizable emotions, but they also demonstrate empathy and what’s called Emotional Contagion. We have only recently been amending the practice of animal farming for human consumption and changing the laws in order that animals are raised more humanely. Would raising pigs for organs be no worse than raising them for food?

Peter Stevenson, from Compassion in World Farming, told the BBC,  “I’m nervous about opening up a new source of animal suffering. Let’s first get many more people to donate organs.”

Of course, it’s not possible for a living donor to give up his or her pancreas or heart, so the sentiment only goes so far as a kidney perhaps. But with further progress towards the humane treatment of animals, might it be possible to benefit both species? How about the pigs bred with human organs be given a life of luxury; uncrowded living conditions, lots of play time and excellent food?

Whatever side you come down on the issue of growing human organs inside pigs, the advent of the “chimera” necessitates a much greater level of debate and imagination before taking the science into a potentially irreversible direction.


Oxford Science Editing specializes in high quality language optimisation by scientist editors, all of whom have advanced degrees. We pair you with an editor who is already well versed in your field and offer peer review-level feedback. Contact us or email info@oxfordscienceediting.com for more information.