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Welcome to the age of synthetic biology – it’s all about yeast

We don’t need evolution any more – we've outsourced the processes to ourselves.

London bread shortage in the 1970s. Yeast genetics are at the vanguard of synthetic biology. Photo: Getty

Evolution’s retirement plan has been 3.6 billion years in the making. With the appearance of the modern human being, we now have an organism that can take over from natural processes and engineer biology in entirely new ways. Welcome to the age of synthetic biology.

The basic idea is that we take an organism – a bacterium, say – and re-engineer its genome so that it does something different. You might, for instance, make it ingest carbon dioxide from the atmosphere, process it and excrete crude oil.

That project is still under construction, but others, such as using synthesised DNA for data storage, have already been achieved. As evolution has proved, DNA is an extraordinarily stable medium that can preserve information for millions of years. In 2012, the Harvard geneticist George Church proved its potential by taking a book he had written, encoding it in a synthesised strand of DNA, and then making DNA sequencing machines read it back to him.

When we first started achieving such things it was costly and time-consuming and demanded extraordinary resources, such as those available to the millionaire biologist Craig Venter. Venter’s team spent most of the past two decades and tens of millions of dollars creating the first artificial organism, nicknamed “Synthia”. Using computer programs and robots that process the necessary chemicals, the team rebuilt the genome of the bacterium Mycoplasma mycoides from scratch. They also inserted a few watermarks and puzzles into the DNA sequence, partly as an identifying measure for safety’s sake, but mostly as a publicity stunt.

What they didn’t do was redesign the genome to do anything interesting. When the synthetic genome was inserted into an eviscerated bacterial cell, the new organism behaved exactly the same as its natural counterpart. Nevertheless, that Synthia, as Venter put it at the press conference to announce the research in 2010, was “the first self-replicating species we’ve had on the planet whose parent is a computer” made it a standout achievement.

Today, however, we have entered another era in synthetic biology and Venter faces stiff competition. The Steve Jobs to Venter’s Bill Gates is Jef Boeke, who researches yeast genetics at New York University.

Boeke wanted to redesign the yeast genome so that he could strip out various parts to see what they did. Because it took a private company a year to complete just a small part of the task, at a cost of $50,000, he realised he should go open-source. By teaching an undergraduate course on how to build a genome and teaming up with institutions all over the world, he has assembled a skilled workforce that, tinkering together, has made a synthetic chromosome for baker’s yeast.

The chromosome works just as well as the natural one and is the first step towards an entirely synthetic yeast. What’s more, the synthetic chromosome already does unusual things. The team can watch it shuffle its genes around, or even delete some. That way, they can identify how evolution over-engineered the organism, and also what variations might make it more useful or interesting.

One of the research partners was Imperial College London, where an international meeting on the future of synthetic biology took place this month. The science minister David Willetts gave the main speech, thanking evolution for its contributions and presenting it with a gold watch.

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