Songbird's Genome Carries Speech Clues

Scientists have sequenced the complete genome of a songbird - the Australian zebra finch - and say the complex mechanisms by which young birds learn songs from their parents offer insight into human speech acquisition.

The international team, led by researchers at Washington University in St. Louis, found that most of the bird's DNA is involved in hearing, imitating, and producing even simple melodies.

Because the analysis traces the vocal learning down to the molecular level - and because humans and finches have much of their genomes in common - the research could lead to strides in combating human speech disorders such as those related to autism, stroke, stuttering and Parkinson's disease.

"The zebra finch genome will be a valuable tool for neuroscientists," said lead author Wes Warren. "They can now carry out studies to identify a core set of genes in the zebra finch brain involved in both hearing and producing song and then look to see if any of these genes are disrupted in people with speech disorders."

Singing activates a large swath of the zebra finch's genes - some 800 in all. The researchers found that many of the genes did not manifest in the traditional way, by coding for proteins. Instead the DNA from these genes helps write short stretches of "non-coding RNA," which in turn affects how other genes are expressed in a cascading effect.

Non-coding RNA is already known to play key roles in developmental processes in humans and in animals.

The zebra finch is only the second bird to have its genome decoded. The first was the chicken. The research is set to appear in the journal Nature on Thursday.