From “How the Zebra Gets Its Stripes: A Simple Genetic Circuit” (ScienceDaily Oct. 14, 2011), we learn:
Now a team of scientists has designed a simple genetic circuit that creates a striped pattern that they can control by tweaking a single gene.
“The essential components can be buried in a complex physiological context,” said Terence Hwa, a professor of physics at the University of California, San Diego, and one of the leaders of the study published October 14 in Science. “Natural systems make all kinds of wonderful patterns, but the problem is you never know what’s really controlling it.”
With genes taken from one species of bacterium and inserted into another, Hwa and colleagues from the University of Hong Kong assembled a genetic loop from two linked modules that senses how crowded a group of cells has become and responds by controlling their movements.
The result of bacterial colony traffic control is target-like concentric rings.
Although individual bacteria are single cells, as colonies they can act like a multicellular organism, sending and receiving signals to coordinate the growth and other functions of the colony. That means fundamental rules that govern the development of these patterns could well apply to critical steps in the development of other organisms.
Well, maybe. Whether that is in fact how the zebra got its stripes is a separate question. As the researchers admit, “the developmental processes that create these and other patterns are complex and difficult to untangle.” But it is a neat experiment and a method for engineering concentric target stripes in bacteria.