Peter Rüegg

They did well, the 12 young ETH Zurich scientists who last year competed with their international rivals in a synthetic biology competition. The challenge had been to design and implement a new function in a living cell using entirely biological components. The students developed a new counter,which was meant to calculate from zero to infinity. This plan was not fully realized: to demonstrate the principle, the interdisciplinary group had to make do with a machine that could count to two. Even though the small apparatus was not finished in time, the ETH team was awarded several distinctions at the competition in Boston (1).

Pure interdisciplinarity

Apart from biologists, electronics engineers, machine engineers and computer scientists were involved in this work – in total, researchers from six different ETH departments. This is a clear indication that synthetic biology entails more than "just" biological science. This was also reflected in the composition of the panel that sat at the first synthetic biology symposium, which took place last Friday at ETH Zurich (cf. box). Sven Panke and Jörg Stelling, assistant professors of bioprocess technology and bioinformatics, respectively, organized the symposium. Although neither comes from the Biology Department, both are part of driving forces at ETH wishing to make synthetic biology better known.

Synthetic biology crosses engineering and computer science approaches with biology. The aim of this relatively young field is to plan and build systems using natural components; a parallel might be to assemble a radio from precisely characterized and standardised transistors, resistors and loudspeaker parts. This is, in fact, biology in building-block format: the manufacture of tiny machines with parts interchangeable according to the various needs of operators and users(2).

Standardised DNA

Standardised components for designed biological systems already exist. Under the guidance of bioengineering pioneer Drew Endy, scientists at MIT have started the cataloging of so-called “BioBricks”. The latter consist of short sections of DNA that either have a fixed function or can generate a specific protein which itself fulfils certain functions. The database already contains over 2000 such standardised DNA components (3).

Reacting to a signal, bacteria light up in green or red: this picture from Ron Weiss's laboratory (Princeton) graces the announcement of the First European Symposium on Synthetic Biology, which took place last week at ETH Zurich. large

Together with many other scientists, Jörg Stelling and Sven Panke are convinced of the potential of this new scientific direction, albeit with certain reservations. "Synthetic biology presents huge opportunities. We can't yet even predict all the areas where it might have an influence," they say.

Photo plate from a bacterial lawn

Many synthetic biology principles are already up and functioning. Students from the University of Texas used E.coli bacteria to produce a light-sensitive photo plate on which they were able to store numerous images. Ron Weiss from Princeton University has manipulated bacteria to the point where they glow in different colours according to their position in relation to a signal.

Most of the development, however, lies in the future. Among other things, Stelling talks of a "doctor in the cell“, a modified cell that can recognise and fight a cancer very early on. Artificial systems can also be produced by imitating the photosynthesis process of green plants, which produce energy very efficiently. "This would be far more efficient than today's solar energy systems," says the bioinformatics specialist.

Researchers are also interested in bacteria into which specific modules might be introduced. These would enable micro-organisms to break down toxic waste from industrial products or to build new, complex molecules. "We're still a long way from this, though. At the moment we're only able to show which principles function," admits Stelling. "But the vision is powerful enough to make patience worthwhile. Just look at what happened to electrophysics after electronics engineers got involved in it," adds Sven Panke.

Guide the ethical debate early

And the dangers must also be acknowledged. As fascinating as research in this field is, knowledge could be abused to produce biological weapons, for example, or especially dangerous viruses. This is why – in addition to synthetic biology pioneers Drew Endy (MIT), Ron Weiss (Princeton) and Luis Serrano (EMBL), who introduced the main features of synthetic biology and presented their work – Peter Schaber, Zurich University Professor of Philosophy, was present at Friday’s symposium to lay out the ethical concerns. Stelling believes it important to take these issues seriously and to integrate them into research at an early stage.