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Montreal, April 18, 2010 A mystery about the mechanism behind sexual mate selection has been resolved. According to a new study published in the journal Nature, Universit de Montral researchers have discovered a molecular switch that becomes activated in response to a potential mate's signal. Simply put, an organism knows that a potential mate is close-by and healthy enough to mate.
"This mating decision is controlled by a simple chemical switch that converts an incoming pheromone signal into a cellular response," says senior author Stephen Michnick, a Universit de Montral biochemistry professor and Canada Research Chair in Integrative Genomics.
"As pheromone signal increases, two enzymes in the cell begin to compete with each other, one adding, the other removing a chemical modification on a protein called Ste5," continues Dr. Michnick, noting that at a critical threshold of pheromone signal, one of the enzymes overwhelms the others' capacity to modify Ste5, triggering a sudden, switch-like cascade of chemical messages to be delivered to the cell to say it's time to mate. The findings were made in collaboration with physicist Peter Swain, of McGill University and the University of Edinburgh, and his postdoctoral fellow Vahid Shahrezaei, now a lecturer at Imperial College London, U.K. They were able to describe with mathematical precision how this switch works to drive the mating decision.
The research team used a single cell organism, i.e. yeast used to leaven bread, for their study. "Although yeast is dramatically different from people, at a molecular and cellular level we have a lot in common," says Dr. Michnick. "The same molecules that create the switching decision in yeast are found in very similar forms in human cells. Similar switching decisions to those made by yeast are made
|Contact: Sylvain-Jacques Desjardins|
University of Montreal