Synthetic biology cells produce light show

By Victoria Gill Science reporter, BBC News

Advertisement

The cells produce waves of light as they express a fluorescent protein

Scientists have produced a very unusual light show, engineering bacterial cells to fluoresce in synchrony.

The researchers turned the cells into synchronised "genetic clocks" - programming them to switch a fluorescent protein on and off.

These waves of activity could eventually be used to make biological sensors, or to programme cells to release timed doses of medicine.

The researchers report the advance in the journal Nature.

Synchronised waves, or oscillations, are important to scientists because they control crucial functions in the human body, such as the sleep-wake cycle, learning processes and the regular release of substances including insulin.

This same team of researchers, which was led by Dr Jeff Hasty from the University of California San Diego, US, first produced "flashing" cells a year ago. These bacterial clocks could be tuned to alter the rate at which they blinked on and off.

But this latest advance allows the cells "talk to each other" and synchronise their activity as they grow into a colony.

"If you want a sensor - if you want to use the rate at which the cells switch on and off to signal something about the environment, you need a synchronised signal," explained Dr Hasty.

To achieve this, he and his team incorporated two genes into the bacterial cells.

The real breakthrough will be when we can do this in mammalian cells Professor Martin Fussenegger ETH Zurich

One of the genes produced what he described as "a negative feedback system". This was the key component that stimulated oscillations in the cells - effectively switching the fluorescent protein on and off.

The other gene produced a chemical that travelled between the cells, allowing them to talk to each other and communicate the rate of his oscillation.

Professor Martin Fussenegger, a scientist from the Swiss science and technology university ETH Zurich, who was not involved in the study, said that this was "the first time that time-keeping devices in different individual cells had been synchronised".

"It's a dramatic achievement. The real breakthrough [will be] when we can do this in mammalian cells, and this has laid the foundation for that," he told BBC News.

"Oscillators could eventually be designed to produce insulin every six hours [in diabetic patients].

"When doctors tell you to take this pill three times a day, that's this is nothing more than an oscillation - a dose at a frequency. An engineered oscillator could do this automatically."

In this same issue of Nature, the editors have marked what many scientists consider to be the 10th anniversary of the birth of synthetic biology - the discipline that sets out to engineer or manipulate life.

"Part of the whole excitement of synthetic biology was to make a branch of molecular biology into an engineering discipline," said Dr Hasty. "The aim is to use computational tools to design biological circuits from scratch.

"We're not quite there yet, but we can already design some of these [simple] systems."

Source