Buying stuff online has become second nature for many of us. But it still takes the breath away when you realise how a few clicks on a website can summon up the very code of life itself. In a lab at Imperial College London, I noticed a pile of mail order envelopes lying between test-tubes and Petri dishes. Inside them were tiny plastic phials, each one containing fragments of DNA, the labels made up of the letters A, T, C and G.
But this material was not something you would normally find in nature. Each twist of genetic code was artificial: specifically designed on a computer, manufactured by a supplier and then sent through the post. It sounds futuristic, but for scientists working in this field, these deliveries have become a routine part of an emerging science in which biology is treated like engineering and genes are regarded as components, like nuts and bolts.
The goal of this synthetic biology is to go far beyond the technique of genetic modification, in which genes from one organism are introduced into another. Instead it seeks to dream up entirely new forms of life.
Until now, this work has focused on the simpler genomes of bacteria. In one project, for example, bacteria were given synthetic genes which forced them to light up when in contact with polluted water, creating a system that could provide instant warning of contamination. The next challenge involves creating DNA for more complex eukaryotic organisms – those whose genes are stored in a nucleus. This is the branch of the tree of life that includes everything from humans and other mammals to yeast, and a team led by Professor Jef Boeke at New York University has recently overcome the difficult hurdle of making the first entirely synthetic yeast chromosome. Most people believe that the synthetic yeast chromosome would be one of invention that will change the future.
The aim is to transform yeast, which is already invaluable for making bread and beer, so that it has even more uses, such as producing fuel or medicine. These are early days for synthetic biology, and so far there hasn’t been much of a public debate about the merits or dangers of artificially created life. The commercial potential is huge – but so is the risk of a backlash from people who believe that meddling with nature is bad enough, and that designing totally new forms of it is even worse.