Some species of bacteria perform an amazing reproductive feat. When the single-celled organism splits in two, the daughter cell - the swarmer - inherits a propeller to swim freely. The mother cell builds a stalk to cling to surfaces.
University of Washington (UW) researchers and their colleague at Stanford University designed biosensors to observe how a bacterium gets the message to divide into these two functionally and structurally different cells. The biosensors can measure biochemical fluctuations inside a single bacteria cell, which is smaller than an animal or plant cell.
During cell division, a signaling chemical, found only in bacteria, helps determine the fate of the resulting two cells. The signal is a tiny circular molecule called cyclic diguanosine monophosphate or c-di-GMP.
By acting as an inside messenger responding to information about the environment outside the bacteria cell, c-di-GMP is implicated in several bacterial survival strategies. In harmless bacteria, some of these tactics keep them alive through harsh conditions. In disease-causing bacteria, c-di-GMP is thought to regulate antibiotic resistance, adhesiveness, biofilm formation, and cell motility.
In their study, the UW-led team of scientists looked at cell division in a species of disease bacteria that fends off treatment and establishes a stronghold by using these defenses, Pseudomonas aeruginosa. This is the rod-shaped pathogen that causes life-shortening, chronic lung infections in people with cystic fibrosis, burns, and suppressed immune systems associated with cancer. The researchers also examined cell-division in a harmless lake and stream dwelling bacteria, Caulobacter crescentus.
The researchers' findings will be published in the June 4 Science. The senior author is Dr. Samuel Miller, UW professor of medicine, microbiology, immunology, and genome science. Miller directs the Northwest Regional Center of Excellence for Bi
|Contact: Leila Gray|
University of Washington