Biological Input/Output Systems (BIOS)
The Biological Input/Output Systems program, also called BIOS, was funded by the Defense Advance Research Projects Agency (DARPA) in 2002. Its goal is to develop and incorporate specific genes into plants, bacteria, yeasts, and prokaryotes that will induce these organisms to act as remote sentinels indicating the presence of biological and chemical substances. These "plug and play" sequences of DNA represent an important step in the development of technology that allow for the assembly of engineered biological pathways within living organisms. For example, an engineered receptor on the exterior of a cell's surface that binds a biological toxin and then signals another pathway within the organism so that it turns different color, activated a fluorescent protein, synthesized a gene product or rearranged a segment of DNA is of particular interest to BIOS. The project aims to produce proof-of-concept examples within three years of initial funding.
An example of a project funded under the BIOS program involves embedding canine olfactory genes that are used in detecting TNT along with the DNA that codes for the pheromone sensing pathway into a yeast's DNA. The potential result is a genetically engineered yeast that can detect explosives. Eventually, these biological sentinels will be grown on sheets that can be deployed in the field. Another BIOS project focuses on engineering new molecular pathways that result in pigment changes in bacteria upon exposure to a variety of bacterial and viral pathogens. A separate project seeks to engineer biological circuits in the E. coli bacterium for sensing biological agents based on the well-known lac and mal operons as models.
█ FURTHER READING:
Defense Advanced Research Projects Agency, Defense Sciences Office < http://www.darpa.mil/dso/thrust/biosci/etc.htm. > (March 11, 2003).