Ellen Jorgensen, co-founder and executive director of Genspace, a community bio-technology lab based in Brooklyn, introduces us to the potentials and risks of CRISPR/Cas9, a system and breakthrough technology to edit genomes. In her workshop, she shows how accessible this technology is and how easy it has become for everyone to design a genetical modification.
The potential of CRISPR ranges from curing diseases to wiping out entire species. What exactly is CRISPR? The acronym stands for "Clustered Regularly Interspaced Short Palindromic Repeats". It is a kind of immune system found in bacteria. A wide range of bacteria and archaea have DNA sequences that are equal to the ones of viruses. These sequences are called CRISPR. They work like a library, a system of reference for known viruses. So if a virus threatens the bacteria and injects its DNA, the bacteria can easily detect it and extract the viruses' DNA.
To identify a virus, the information stored in the CRISPR sequence is copied to an RNA that is bind to a Cas9 enzyme. The RNA recognizes sequences that were implanted by a virus and guides the Cas9 to the right position to cut and destroy them.
From a Bacterial Defense Mechanism to a Word Processor for Gene Editing
This mechanism can be used to cut genes and replace them with an edited version. The technology is more affordable, precise, easy and faster to use than previous techniques (such as using TALENs or Zinc finger nucleases). Ellen guides us through a handful of website-based services to design a genetic modulation. As an example she targets a gene of yeast. The peace of DNA has 20 letters which you can buy for about 20 dollars. If you would like to dive deeper into engineering gene modulations, you can check out the addgene CRISPR guide, Ellen recommends.
While the system is so easy and accessible – and you can rely on remote labs instead of tinkering yourself, there are a lot of risks involved – or at least a lot of open ethical questions. Regulations governing genetic modification in human embryos, for instance, do vary a lot. The US does not allow the use of federal funds, but there are no bans for genome editing. Germany does have strict rules: Gemline gene editing could end in criminal charges. Whereas in China, scientists have already experimented with modifying genes in human embryos. And the UK has just granted permission to a Crick Institute researcher engineering early-stage human embryos to study their development.
Where to draw the line?
Of course, the technology could be used to cure severe congenital diseases – you obviously do not want babies to have life-threatening diseases. However, what if parents would like their kids to be smart, male or to look a certain way?
Right now, there is also no clear regulatory framework for wiping out a species through genetic engineering. And there are already plans to do so. Ellen shows an example of a "gene drive" combined with CRISPR that could reduce the population of Aedes aegypti mosquitoes – the ones that are more likely to transmit the Zika virus – by 99%. With a normal inheritance, you have a 50% chance that the altered gene will be passed on. As a "gene drive" the altered gene is almost always inherited and thus will take over the population.
Wrapping up, Ellen quotes the concerns of Todd Kuiken of Wilson Policy Center: "Man has been engineering nature and ecosystems ever since we came out of the cave. What is different now is that we are beginning to engineer species. It is a progression on the scale, and it is a big progression."
For better or worse – the technology is out there, you will not be able to put it back. However, people should know about the potentials and risks and there should be an open public debate about how we would like to apply it instead of a small elite deciding upon how far we want to go in modifying life.