In a recent paper published in Current Biology, Professor Ichiro Maruyama, head of the Information Processing Biology Unit at OIST, and colleagues have uncovered the molecular and cellular mechanisms behind how an organism senses alkalinity in its environment. While much is known about how acidity is monitored, this is the first research to uncover the basis for how an organism, specifically the worm Caenorhabditis elegans, monitors alkaline pH.
pH is a measure of the hydrogen ion concentration in a solution. Substances with a pH less than 7 are considered acidic and those with a pH greater than 7 are basic or alkaline. All biological systems, from the cell to the organism to the ecosystem, favor a particular pH range. Not all systems prefer the same range, however: some bacteria are known to thrive in extremely high or low pHs. Though the human body averages out to have a roughly neutral pH, tissues in the stomach can handle pH1, while tissues in the pancreas prefer roughly pH 8.
To uncover the cellular and molecular mechanisms for how an organism might sense alkalinity, Maruyama and his group used C. elegans, a worm that can thrive in conditions up to a pH 10.4. The worm’s preference for alkalinity allowed the researchers to test normal and genetically mutated individuals to pinpoint the specific neuron and accompanying protein pathways associated with sensing alkalinity. They found that when the gene that is required for functioning of the neuron ASEL, also associated with the worm’s sense of taste, is removed, the worm can no longer sense alkalinity in its environment. The group also uncovered the specific proteins that mediate ASEL’s activity in the brain with alkaline stimuli from the worm’s environment.
“It’s hard to say whether the exact same mechanisms are occurring in humans,” says Professor Maruyama, “but our research provides other scientists with a good place to start looking for the same phenomenon in us.”
If the mechanism behind how human brains sense alkalinity in the environment and tissues is uncovered, it could aid in finding better treatments for ailments caused by imbalances in pH, such as high blood pressure and infertility in men.
