Super Synthetic: Why Your Cells Might Be Smarter Than Your Calculator
Synthetic biologists have programmed a mammalian cell to calculate basic logical operations thanks to a highly complex artificial gene network.
A team of researchers from ETH Zurich headed by Martin Fussenegger, a professor of biotechnology and bioengineering at ETH Zurich’s Department of Biosystems in Basel, has constructed a gene network that can perform logical operations and, as a result, initiate specific metabolic steps. “We have developed the first real cellular calculator,” says Fussenegger.
Using biological components, the researchers developed a set of different elements that can be interconnected in different combinations and subsequently perform logical operations. These circuit elements, which are known as “logic gates” in the jargon, use the apple molecule phloretin and the antibiotic erythromycin as input signals. The calculations performed are based on Boolean logic.
“By combining several logic gates, we have achieved an unprecedented level of complexity in the synthetic gene network in cells,” stresses Professor Fussenegger. Even more remarkably, the bio-computer can process two different input and output signals in parallel. This sets the bio-computer apart from digital electronics, as this only works with electrons.
“Of course, our cell calculator is nowhere near as efficient as a PC,” says the ETH-Zurich professor. “By nature, however, a cell can process many different metabolic products in parallel.”
By combining and interconnecting several logic gates, the biotechnologists ultimately obtained a “half-adder” and “half-subtractor”: Both central circuit elements in computer technology. A half-adder is a basic digital circuit that adds up two binary numbers; the half-subtractor, on the other hand, deducts them. These two elements are found in every digital calculator, where they perform most calculations. In cell-structure experiments, the two bio-computer components produced solid results.
Scientists hope that these “cell calculators” can be widely used for a variety of applications, including monitoring and regulating a patient’s metabolism to help with diseases like diabetes. While still a far cry from medical applications, Professor Fussenegger is optimistic. “It’s [just] wonderful that a mammalian cell can calculate like that!” he beams.