Scientists have long been curious about how bacteria decide which of these paths to pursue. Years of studies have determined that each individual constantly senses its environment and continuously sends out chemical signals to communicate with its neighbors about the choices it is making. Experimental studies have revealed dozens of regulatory genes, signaling proteins and other genetic tools that cells use to gather information and communicate with one another.
"Bacteria don't hide their intentions from their peers in the colony," said study co-author Jos Onuchic, co-director of CTBP, Rice's Harry C. and Olga K. Wiess Professor of Physics and Astronomy and professor of chemistry and biochemistry and cell biology. "They don't evade or lie, but rather communicate their intentions by sending chemical messages among themselves."
Individual bacteria weigh their decisions carefully, taking into account the stress they are facing, the situation of their peers, the statistics of how many cells are sporulating and how many are choosing competence, Onuchic said. Each bacterium in the colony communicates via chemical "tweets" and performs a sophisticated decision-making process using a specialized complex gene network comprised of many genes connected via complex circuitry. Taking a physics approach, Onuchic, Ben-Jacob and study co-authors Mingyang Lu, Daniel Schultz and Trevor Stavropoulos investigated the interplay between two components of the circuitry -- a timer that determines when sporulation occurs and a two-way switch that causes the cell to choose competence over sporulation.
|Contact: Jade Boyd|