Bacteria Made to Behave as Computers

hende_jman writes "Scientists at Princeton University successfully 'programmed bacteria to behave like computers, assembling themselves into complex shapes based on instructions stuffed into their genes.' Though applications may not come for awhile, the article says that in the future this technology may be used in devices to detect bioterrorism chemicals. The article also has pictures of the programmed E. coli."

Comments

Wired Article

[Brendor]

Wired did an article about a similar notion back in 1995 which was rather interesting at the time.

Relevant research publications

[FleaPlus]

::digs around for relevant info::

First off, here's the web page for Ron Weiss, the scientist mentioned in the article.

Here's (what I think is) the relevant publication on the topic:

A synthetic multicellular system for programmed pattern formation

Subhayu Basu, Yoram Gerchman, Cynthia H. Collins, Frances H. Arnold and Ron Weiss

Nature 434, 1130-1134 (28 April 2005)

Pattern formation is a hallmark of coordinated cell behaviour in both single and multicellular organisms1, 2, 3. It typically involves cellcell communication and intracellular signal processing. Here we show a synthetic multicellular system in which genetically engineered 'receiver' cells are programmed to form ring-like patterns of differentiation based on chemical gradients of an acyl-homoserine lactone (AHL) signal that is synthesized by 'sender' cells. In receiver cells, 'band-detect' gene networks respond to user-defined ranges of AHL concentrations. By fusing different fluorescent proteins as outputs of network variants, an initially undifferentiated 'lawn' of receivers is engineered to form a bullseye pattern around a sender colony. Other patterns, such as ellipses and clovers, are achieved by placing senders in different configurations. Experimental and theoretical analyses reveal which kinetic parameters most significantly affect ring development over time. Construction and study of such synthetic multicellular systems can improve our quantitative understanding of naturally occurring developmental processes and may foster applications in tissue engineering, biomaterial fabrication and biosensing.

This conference abstract is also pretty darned cool:

Dynamic Control in a Coordinated Multi-Cellular Maze Solving System

Hsu, Allen (Princeton Univ.), Vijayan, Vikram (Princeton Univ.), Fomundam, Lawrence (Univ. of Maryland, Baltimore County), Gerchman, Yoram (Princeton Univ.), Basu, Subhayu (Princeton Univ.), Karig, David (Princeton Univ.), Hooshangi, Sara (Princeton Univ.), Weiss, Ron (Princeton Univ.)

2005 American Control Conference

Control system theory provides convenient tools and concepts for describing and analyzing complex cell functions. In this paper we demonstrate the use of control theory to forward-engineer a complex synthetic gene network constructed from several modular components. Specifically, we present the design and simulation of a synthetic multi-cellular maze-solving system. Here, bacterial cells are programmed to use artificial cell-to-cell communication and regulatory feedback in order to illuminate the correct path in a user-defined maze of cells arranged on a surface. Simulations were used to analyze the system's spatiotemporal dynamics and sensitivity to various kinetic parameters. Experiments with Escherichia coli were carried out to characterize the diffusion properties of artificial cell-to-cell communication based on bacterial quorum sensing systems. The rational design process and simulation tools employed in this study provide an example for future engineering of complex synthetic gene networks comprising multiple control system motifs.

The MIT Standard Registry of Biological Parts

[supersat]

Last week, Dr. Drew Endy from MIT gave a talk to the University of Washington's CSE department on Building Biological Systems (PowerPoint slides are here).

At first glance, building biological systems seems like a pretty daunting task. You have all of these As, Ts, Gs, and Cs, and your task is to figure out how to order them to make your system work as specified. And unlike computers that were engineered by humans, the biological mechanisms that work on DNA aren't completely understood.

However, a promising method of engineering biological systems is to abstract them into systems, devices, and parts. One of the interesting things they're doing is building a repository of biological parts, available at http://parts.mit.edu/. These parts use a standardize way of communicating with each other, allowing you to combine them easily.

Using these parts, college students are able to engineer biological systems in a single quarter. In fact, there's been a few intercollegiate biological engineering competitions, linked to from the MIT Parts site.

Re:Call me cynical...

[dr eldritch]

What you've got to understand is that "programming" cells to aggregate in a predictable fashion does not confer any new toxic properties to the cells...just the shape of the "tissue" that they are forming. The cells retain all of their old toxin-producing capabilities--should they have them--and are otherwise uninfluenced. In fact, scientists have been able to modify bacterial genomes for years with plasmid cloning...we've long had the ability to insert new genes into bacteria to make them more virulent. This "novel" technique merely uses old plasmid cloning and gene splicing technology to make the bacteria act in a predictable fashion in the presence of some local environmental cue, thus allowing them to serve as indicators of something in the environemnt when touched with it. Nevertheless, if you really want to be paranoid about something, look up the article published in Nature about 1.5 years or so ago wherein a couple of scientists reported building a smallpox virus from scratch. That's right. From scratch. It was accomplished after about 2 weeks worth of work.