Scientists at Universite de Montreal, solving the mystery on the mechanism behind sexual mate selection, have hit upon a molecular switch that becomes activated in response to a potential mate's signal.
This means that 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," Nature quoted senior author Stephen Michnick, as saying.
"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," added Michnick.
He claimed 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 researchers could describe with mathematical precision how this switch works to drive the mating decision.
They 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. 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 by stem cells during embryonic development and become dysfunctional in cancers," said Michnick.
Using yeast enabled the research to show how a cell might make important decisions.
"When yeast cells decide to mate, they must know that there is a mating partner close enough, and then make a snap decision to get ready to mate", said first author and graduate student Mohan Malleshaiah.
"Their decision to mate is not just fast, but precise, resulting in their selection of the best available partner, even though there may be many competing potential mates near by," added Malleshaiah.
The study has been published in the journal Nature.