Josiah Zayner is a self-proclaimed bio-hacker. He sells CRISPR/CAS9 home gene editing kits, and he goes to conferences where he publicly injects himself with chemicals to modify his own genes. For instance, at a biotech conference, he got up on stage and injected himself with a cocktail to knock out the myostatin gene, to give himself “bigger muscles”.
If you want to genetically modify yourself, it turns out, it’s not necessarily complicated. As he offered samples in small baggies to the crowd, Zayner explained that it took him about five minutes to make the DNA that he brought to the presentation. The vial held Cas9, an enzyme that snips DNA at a particular location targeted by guide RNA, in the gene-editing system known as CRISPR. In this case, it was designed to knock out the myostatin gene, which produces a hormone that limits muscle growth and lets muscles atrophy. In a study in China, dogs with the edited gene had double the muscle mass of normal dogs. If anyone in the audience wanted to try it, they could take a vial home and inject it later. Even rubbing it on skin, Zayner said, would have some effect on cells, albeit limited.
He does not look particularly muscular in his photos.
He’s a snake-oil salesman. He’s doing this demonstration, confident that nothing will go wrong, because he must know that this is a spectacularly inefficient way to use CRISPR/CAS9. I looked over his website, and there’s no information on the frequency of incorporation of his edited sequence into cells, or even on whether they’ve seen any phenotypic effects with this approach. I suspect there’s little effect, which is a good thing. Even if he does get incorporation into some cells, he’s not going to get much of a result — myostatin affects the growth and differentiation of myocytes (it’s not going to do a lot for an adult), and regulates protein synthesis in muscle cells, which could, in fact, promote more ‘bulking up’ of existing muscle mass.
That’s not necessarily a good thing. Cardiac hypertrophy is not something you want to have, and Zayner isn’t exactly controlling delivery of his reagents to specific subsets of muscle cells.
But again, he’s almost certainly not getting enough DNA modification to have either his desired result or a deleterious result. He’s just gambling that the injections will be innocuous enough that they won’t actually do anything except look impressive to the rubes. Here’s hoping he doesn’t get erroneous editing of random cells so that basically, all he’s doing is giving himself a low-dose mutagen.
George Church is the voice of reason on this one.
If you modify your DNA, it’s possible to then sequence your DNA to see if you made the targeted change. But a garage experiment also can’t provide as much information as more conventional methods. “You can confirm that you’ve altered the DNA, but that doesn’t mean that it’s safe and effective,” says George Church, professor of genetics at Harvard Medical School (who also serves as an advisor to Zayner’s tamer kit company, recognizing the value of a biology-literate public in what’s being called the century of biology). “All it does is tells you that you’ve molecularly done the right thing, but it could be unsafe because you’ve also done something off-target. It could be ineffective in the sense that not enough cells were altered, or it’s too late in life and the damage has already been done.” If a baby is born with microcephaly, for example, changing the genes in its body likely won’t be able to change the effects of the condition on its brain.
Zayner’s vial of CAS9 myostatin knock-out juice is really cheap, at only $20. It also makes me wonder about quality control and safety at his workplace, though. I’d worry more about contaminants in a random vial of fluids that I’m expected to inject into my bloodstream than that it contains the latest biotech buzzword.




