The singing lab mouse

It is usually the male mice who do the singing. Image: Bret Pasch

Genetics help mice express themselves in song.

They aren’t exactly your average lab rats — singing mice (Scotinomys teguina) come from the tropical cloud forests of the Costa Rican mountains and express themselves, as their name suggests, through songs. But their unique singing behaviour could help scientists understand and identify genes that affect language in humans, according to University of Texas researcher Steven Phelps.

Most rodents vocalise at a frequency too high for humans to hear, but then, unlike the singing mouse, these species aren’t usually communicating over long distances in the wild. “They sound kind of soft to human ears, but if you slow them down by about three-fold they are pretty dramatic,” Phelps says.

The song itself consists of a rapid-fire string of high-pitched chirps, with a male mouse squeaking out up to 20 chirps per second to establish dominance or attract a mate. It sounds like bird chirps unless you know what you’re listening for — unlike birds, the mice stick to a song made up of a single note.

But Phelps and his team aren’t just listening to the songs for enjoyment — they’re examining which genes influence song expression and have already identified one possible candidate: FOXP2, which is remarkably similar between humans, singing mice and lab mice. It has also been associated with various language problems in humans, from having problems with grammar to not being able to make the right mouth movements needed to produce a clear sentence.

This gene helps control the expression of other genes, so a mutation can cause reduced or no expression of these. The researchers are figuring out just what activates FOXP2 in the singing mice by playing recordings of their songs, observing the gene expression patterns and testing them for evidence of natural selection.

“We found that when an animal hears a song from the same species, these neurons that carry FOXP2 become activated. So we think that FOXP2 may play a role in integrating that information,” post-doctoral researcher Lauren O’Connell says.

Using the supercomputers Lonestar and Ranger to crunch the vast amounts of data, the researchers can decipher how FOXP2 interacts with DNA to regulate the function of other genes. “We ask two things, whether there are sequence changes in the DNA that are associated with the elaboration of the song and whether particular elements seem to be interacting with FOXP2 more,” said Phelps. “That gives us leads into what role FOXP2 might play into the elaboration of vocalisation.”

Source: University of Texas

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