Washington, April 16 (ANI): Scientists from the Monell Center in the US have reported that the red panda is the first non-primate mammal to display a liking for the artificial sweetener aspartame.
The research related sweet preferences to genetic analyses of sweet receptor structure in six related species.
Each of the species tested - red panda, ferret, genet, meerkat, mongoose, and lion - belongs to the Order Carnivora.
By studying the structure and function of the sweet receptor gene across species and how this relates to differences in taste preferences and diet selection, the researchers seek to provide a framework to increase understanding of individual differences in human taste function, food choice and nutritional health.
"The taste world of every species, and even every individual, is unique, defined in part by the structure of their taste receptors," said Monell comparative geneticist Xia Li.
In the study, preferences for six natural sugars and six artificial sweeteners were tested in a zoo setting.
For each sweet molecule, the animal was given access to both the sweet solution and water for 24 hours. The animal was said to prefer the sweet solution when it drank much more sweet fluid than water.
DNA samples from each species were used to examine the structure of the sweet receptor gene Tas1r2, which codes for the T1R2 sweet taste receptor.
Because only primates were believed to be able to taste aspartame, the researchers predicted that none of the Carnivore species tested would show a preference for the artificial sweeteners.
This indeed was the case for five of the species. However, the sixth species - the red panda - drank large amounts of the artificial sweeteners aspartame, neotame, and sucralose.
Seeking to explain this unexpected behavior, the researchers compared Tas1r2 genes from various species that can and cannot taste aspartame.
They were surprised to find no consistent differences between aspartame tasters and nontasters.
However, the genetic analysis did reveal that the red panda's sweet receptor has a unique structure that is different from any of the other species examined.
This unexpected affinity for an artificial sweetener may reflect structural variation in the red panda's sweet taste receptor.
"The red panda's unique taste receptor gives us a tool to broaden our understanding of how we detect sweet taste," said Joseph G. Brand, a biophysicist at Monell.
"Greater insight into why we like artificial sweeteners could eventually lead to the development of more acceptable sugar substitutes, potentially benefiting diabetics and other individuals on sugar-restricted diets," he added. (ANI)