Scientists unearth the origins of singing mice

The singing mice are tawny brown fur rodents instead of the common white albino strain and hail from tropical cloud forests in the mountains of Costa Rica.

University of Texas at Austin researcher Steven Phelps is examining these unconventional rodents to gain insights into the genes that contribute to the unique singing behavior, an information that could help scientists understand and identify genes that affect language in humans.

"We can choose any number of traits to study but we try and choose traits that are not only interesting for their own sake but also have some biomedical relevance," said Phelps.

"We take advantage of the unique property of the species."

The song of the singing mouse song is a rapid-fire string of high-pitched chirps called trills used mostly used by males in dominance displays and to attract mates.

Up to 20 chirps are squeaked out per second, sounding similar to birdsong to untrained ears. But unlike birds, the mice generally stick to a song made up of only a single note.

"They sound kind of soft to human ears, but if you slow them down by about three-fold they are pretty dramatic," said Phelps.

Most rodents make vocalizations at a frequency much too high for humans to hear. But other rodents typically don't vocalize to the extent of singing mice, which use the song to communicate over large distances in the wild, said Andreas George, a graduate student working in Phelps' lab.

Phelp's research on the behavior of the mouse has appeared in the journals 'Hormones and Behaviour' and 'Animal Behaviour'.

His newest research project is examining the genetic components that influence song expression and at the center stage is a special gene called FOXP2.

"FOXP2 is famous because it's the only gene that's been implicated in human speech disorders specifically," said Phelps.

Having at least one mutated copy of the gene has been associated with a host of language problems in humans, from difficulty understanding grammar to an inability to make the precise mouth movements needed to speak a clear sentence.

The FOXP2 gene is remarkably similar overall between singing mice, lab mice and humans, said Phelps.