[an error occurred while processing this directive]
Skip to Main Content

Latest News

Advertisement
Advertise Here
December 13, 2010
Volume 88, Number 50
p. 10

Cell-Mediated Computation

Synthetic Biology: Engineered cells can be combined into complex circuits, researchers show

Celia Arnaud

Circuit Diagram Cells (spheres) designed to carry out specific logic functions can be “wired” together with signaling molecules (blue) to carry out complex functions. The white drawings on the spheres are symbols used in electrical circuit diagrams. Ricard Solé
Circuit DiagramCells (spheres) designed to carry out specific logic functions can be “wired” together with signaling molecules (blue) to carry out complex functions. The white drawings on the spheres are symbols used in electrical circuit diagrams.
  • Print this article
  • Email the editor

Latest News



October 28, 2011

Speedy Homemade-Explosive Detector

Forensic Chemistry: A new method could increase the number of explosives detected by airport screeners.

Solar Panel Makers Cry Foul

Trade: U.S. companies complain of market dumping by China.

Novartis To Cut 2,000 Jobs

Layoffs follow similar moves by Amgen, AstraZeneca.

Nations Break Impasse On Waste

Environment: Ban to halt export of hazardous waste to developing world.

New Leader For Lawrence Livermore

Penrose (Parney) Albright will direct DOE national lab.

Hair Reveals Source Of People's Exposure To Mercury

Toxic Exposure: Mercury isotopes in human hair illuminate dietary and industrial sources.

Why The Long Fat?

Cancer Biochemistry: Mass spectrometry follows the metabolism of very long fatty acids in cancer cells.

Text Size A A

Scientists have moved a step closer to being able to program cells as they would program computers. Two independent groups show it is possible to distribute biological “computations” over multiple cells that perform different logical functions and communicate with one another through signaling molecules that serve as chemical “wires.”

The ability to divide computations among different cells means the cells can be used to build circuits analogous to those in electronics. The idea is to be able to harness the power of biology to create sensors and other useful devices.

“We’re proposing a very simple circuit to be the building block of constructing programs in bacteria,” says Christopher A. Voigt of the University of California, San Francisco, who led one team. That simple circuit is a NOR gate, which is on only when both of its inputs are off. NOR gates are unusual in that they can be combined to form any of the other gates in Boolean logic.

For their NOR gates, Voigt and coworkers use pairs of promoters to control the production of gene repressors (Nature, DOI: 10.1038/nature09565). When both promoters—the gate inputs—are present, the repressor is turned on and the gate does not produce its output (expression of a gene). In the absence of the promoters, the repressor is also inactive and the gene is turned on. The DNA sequences for the promoters, repressors, and genes are incorporated in the bacteria via genetic engineering.

Bacteria can be genetically modified so each strain is a different logic gate. The gates are wired together by chemical signals between cells. The product of one gate diffuses to and becomes one of the inputs for the next gate in the circuit. The spatial arrangement of different strains determines the output of the overall system.

In separate work, Ricard Solé, Francesc Posas, and coworkers at Pompeu Fabra University, in Barcelona, show that a small number of different types of cells can be combined to create a large number of different circuits with different functions (Nature, DOI: 10.1038/​
nature09679). “We can use [cells] in a combinatorial way,” Solé says. “Potentially we can generate thousands of different circuits and so implement thousands of different functions.”

The Spanish team engineered yeast cells and combined them in various ways to perform specific logic functions, such as multiplexing and one-bit binary addition with carry.

The findings from both teams “represent significant advances in the number and types of logical operations that cell consortia can perform,” says Justin P. Gallivan of Emory University. “Some of the next big challenges include developing more robust networks that can respond to a wider variety of small-molecule inputs and produce more sophisticated output signals.”

Chemical & Engineering News
ISSN 0009-2347
Copyright © 2011 American Chemical Society
  • Print this article
  • Email the editor

Services & Tools

ACS Resources

ACS is the leading employment source for recruiting scientific professionals. ACS Careers and C&EN Classifieds provide employers direct access to scientific talent both in print and online. Jobseekers | Employers

» Join ACS

Join more than 161,000 professionals in the chemical sciences world-wide, as a member of the American Chemical Society.
» Join Now!