February 25, 2004

What bacteria want to say

Bill Poser has just pointed us to information about what cats have to say: "Love you? Heck no. I'd eat you if you weren't so damn big," said Marchessa Yolanda Principessa des Astres, a Siamese cat from New Jersey, to her owner and handler, Fran Dershowitz. "Well, I'd bat you around first."

The February Scientific American has an article on signals for quorum sensing in bacteria. Quorum sensing was discovered about 40 years ago: some bacteria are bioluminescent when their population density is high enough, but turn off the lights when they're alone; others use quorum sensing as a switch for biofilm production, toxin generation and so forth. The article attributes to J. Woodland Hastings and Kenneth H. Nealson, the discoverers of the effect, the view that bacteria "[cry] out, like Horton the elephant's dust speck in the Dr. Seuss book, 'We are here! We are here! We are here! We are here!'"

The new news is work by Bonnie Bassler suggesting that in addition to the autoinducer and sensor proper to quorum sensing among their own kind, many bacteria have a second kind of signal, AI-2 ("autoinducer 2") that communicates quorum information across many diverse bacterial types. She refers to it as "bacterial Esperanto".

My favorite part of the article, though, is the mildly peevish quote from Stephan Winans at Cornell: ""Do bacteria want to communicate with each other, or is it just by accident? This idea has taken hold that these bacteria want to communicate with each other. It may be just too good to be true." I feel that this is a profound insight, with important applications in human relations as well.

Posted by Mark Liberman at February 25, 2004 08:58 AM