When I was eight or nine, one of my Christmas presents was an illustrated book called How And Why It Works, which explained everything from airliners to oil-wells and telescopes.
It immediately became my favourite. My course in life was set there and then. I wanted to know how everything works including you and me so I became a biochemist and then, through a series of flukes, a computer nerd.
Books can still have that sort of effect on me, though rarely nowadays, and when one does I occasionally write about it here. The last time it happened was in August 2016 when Endless Forms Most Beautiful by Sean B. Carroll overcame my reluctance to get to grips with Evolutionary Developmental Biology (evo-devo). That book helped me understand that all living things are indeed computational systems, but not in the naive way that the AI brigade would have us believe.
Every living thing contains a genetic apparatus that combines a database of inherited features with a collection of distributed, self-modifying, real-time processors and 3D printers whose outputs are flesh, blood and bones, leaves, bacterial cell walls, as well as nerves and brains.
Well, it's just happened again. I'd been aware for several years of a revolution in gene editing, one that will enable us to reprogram this system (for better or for worse). But, as with evo-devo, I had pushed it to the back of my mind, unwilling to tackle the mental effort needed to understand it.
What's fortified me this time around is an article in the London Review of Books by Dr Rupert Beale, which explains the new techniques of CRISPR.
Beale researches bacteriophages, viruses that infect bacteria. It was work on phages around 20 years ago (by a Danish industrial yoghurt company among others) that triggered this revolution. Bacteria, though just single cells, have evolved a very simple immune system whenever they survive a phage attack, they snapshot a chunk of its genetic sequence into their own DNA as a memory of the crime.
In any future infection, a bacterium can recognise that sequence and use an enzyme called Cas9 to snip it out, thus killing the phage. These snapshots consist of "clustered regularly interspaced short palindromic repeats" CRISPR for short.
Those of you involved in computer security might recognise this as much the same mechanism used by AV software to detect computer viruses from their "signature" code sequence. Molecular geneticists can now deploy the combination of CRISPR and Cas9 as tools to cut-and-paste gene sequences into the DNA of other creatures besides bacteria, up to and including homo sapiens.
In practice, they don't actually snip out target genes but rather disable them: Cas9 cuts the DNA strand but the host cell repairs it, over and again until it makes a mistake so that the gene stops working. Knock out all 20,000 genes in the human genome one at a time and you can build a vast library of gene-removed cells, for example, to test cancer chemotherapy drugs by finding which genes are involved in a response.
As Beale explains: "With CRISPR-Cas9 techniques we can kill genes, switch them on and, if we are lucky, replace bits of one gene with another. It doesn't stop there: the guidance system can be employed to perform almost any function that can be bolted onto a protein."
In other words, CRISPR will make it possible to directly code the human genome, and we'll soon be seeing patches that cure specific genetic diseases, add resistance to infections and more. Patch Tuesday could become something you do at your local clinic as well as on your PC. Of course, the risks, as well as the benefits, of patching will quickly become apparent (hopefully they won't be as bad as Windows 10).
CRISPR has become big business and there are ongoing squabbles over the patent rights between various corporations and universities. Jennifer Doudna, a leading CRISPR researcher at UC Berkeley, in her excellent book A Crack in Creation, tackles some of the ethical issues that will arise as we supplant "the deaf dumb and blind system that has shaped genetic material on our planet for eons and replace it with a conscious intentional system of human directed evolution".
If GM lettuces created a worldwide protest, expect way more at the prospect of GM babies.
Image: Shutterstock
