What Gene-Altering for Pigs and Ants Might Mean for Humans


A scientific advance using genetically edited piglets could lower the fatality rate and make using pig organs, similar to our own, a common practice. The result was animals that were not carrying active forms of the potentially harmful viruses, which would normally become integrated into the offspring's DNA.

"Our work fundamentally addressed the risk of cross-species viral transmission in xenotransplantation", Yang told Xinhua.

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Creating PERV-free pigs is the first step in a four-step process to ultimately create pig organs suitable for human transplant or "xenotransplantation", Dr. Luhan Yang, a co-founder of eGenesis and the company's chief science officer, explained to HuffPost.

In particular, the pig genome is known to carry porcine endogenous retroviruses (or PERVs), which are capable of transmitting diseases, including cancers, into humans.

Concerns over these infections being passed from pig to patient have been a major stumbling block in the quest to find an alternative to human organ donation.

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The United Network for Organ Sharing says the list of people who need an organ to save their lives is in the tens of thousands, with kidneys representing the greatest need. Now, without the threat of these hidden diseases, it may be possible to safely transplant pig livers, hearts, and other organs. So, while it's unclear how threatening these viruses are to humans in practice, they do at least have the ability to jump to humans. Previous experiments have worked toward customizing pig organs to make them compatible with human recipients.

Formidable obstacles remain "in overcoming immunological rejection and physiological incompatibility of pig organs in humans", he said.

eGenesis says it will continue to monitor the piglets for any long-term effects and, according to Yang, will also "further engineer the PERV-free pig strain to deliver safe and effective xenotransplantation". These edited cells were then used to create embryos that were implanted into sows and the birthed piglets were born virus-free. Pigs are the biggest animals that have undergone CRISPR, he says, and he wants to see what happens when they are allowed to "grow to a ripe old age" of over 20.

Tests demonstrated that pig cells could infect human cells with Pervs in the laboratory.

There is a drastic shortage of organs available for transplants around the world. He and his colleagues recently attempted to chop PERV genes out of pig cells with an editing technology called zinc finger nucleases, but the many imprecise DNA cuts proved toxic to cells.

To do that, you first genetically modify pig cells. The research is basically a "safety check", says Pablo Ross, a geneticist at the University of California, Davis, who did not take part in the study.