People's fondness for salty snacks reflects a fundamental biological imperative. "All cells, in order to survive, need salt," says Lei Liu of the Howard Hughes Medical Institute at the University of Iowa in Iowa City. To keep themselves supplied with this critical nutrient, animals have developed ways for sensing sodium chloride and other salts.
By creating mutant fruit flies with an impaired capacity to taste salt, Liu and his colleagues have now identified several genes that contribute to this crucial sensory system in insects. Liu suggests that the fly research could provide insights into how people taste salt. It may even lead to an effective salt substitute to fight high blood pressure and other conditions exacerbated by today's salt-rich diets, he speculates.
When it comes to salt, the fruit fly Drosophila melanogaster acts much like a person. Food or water sources with too much salt repel the flies, but those with low concentrations attract them. The fli