Human “language gene” found to work in mice, too

<body leftmargin="0" bgcolor="#000060" text="#FFFFFF" link="#FFFF00" vlink="#FF9900"> <b> <p class="MsoNormal"><font face="Arial" size="5">Human “language gene” found to work in mice, too</font></p> <p class="MsoNormal"></b><font face="Arial" size="1">June 24, 2005<br> Courtesy Mount Sinai Medical Center<br> and World Science staff<br> </font> <b> <font size="2" face="Arial"><br> A gene believed to give humans the gift of language also seems to enable mice to communicate, showing the genetic roots of language run deep, researchers said.  </font></b> </p> <b> <p class="MsoNormal"><font size="2" face="Arial">The gene, called Foxp2, was first linked to language in a study of a family half of whose members had severe speech and grammar impairments. Researchers found all the affected members had a mutation in the gene. <br> <br> The gene is found on a region of a human chromosome—chromosome 7—linked to other disorders that affect speech, including autism.</font></p> <p class="MsoNormal"><font size="2" face="Arial">Mice also have a version of the gene. In a new study, researchers engineered mice with either one or both copies of it disrupted, to learn more about its role in communication. </font></p> <p class="MsoNormal"><font size="2" face="Arial"> The treatment curbed the ability of the mice to emit high-pitched squeaks called ultrasonic vocalizations when separated from their mother and littermates, according to the study’s leader, Joseph D. Buxbaum of the Mount Sinai School of medicine in New York City.<br> <br> Mice with both copies of Foxp2 disrupted stopped making the sounds completely, while mice with one disrupted gene made significantly less of them, the researchers said. The doubly-disrupted mice also displayed severe motor skill impairment and died early, they added; single-copy mice had more modest, but still noticeable, developmental delays.<br> <br> “Our findings demonstrate that Foxp2 subsumes communication across species, and, as a result, we can legitimately use the mouse to learn about the neurobiology of human speech and articulation,” said Buxbaum, whose paper was published online last week in the research journal <i> Proceedings of the National Academy of Sciences.</i></font></p> <p class="MsoNormal"><font size="2" face="Arial">But other researchers have found the human Foxp2 is slightly different that of animals, including our ape relatives, showing evolutionary forces reshaped the gene not long ago. These findings were published in the Aug. 22 issue of <i>Nature, </i>another scientific journal.</font></p> <p class="MsoNormal"><font size="2" face="Arial">A major question is exactly what the gene does to promote communication.<br> <br> In mice, Foxp2 disruption didn’t seem to affect the vocal tract, said the Mount Sinai researchers, suggesting the gene doesn’t have roles in that area. </font></p> <p class="MsoNormal"><font size="2" face="Arial">Rather, they said, studies suggest the gene influences cell development in the cerebellum, a brain region considered responsible for coordinating complex voluntary muscular movements, maintaining posture and balance. <br> <br> “It has been hypothesized that speech is somehow a finer example of a motor pathway -- a more demanding, more subtle pathway, but still a motor pathway,” said Buxbaum. The mouse studies support this idea, he added.<br> <br> The Foxp2 mice may also allow researchers to investigate how this gene is related to autism, the researchers said. A few studies suggest that Foxp2 is an autism-susceptibility gene, although a majority view is that Foxp2 is not such a gene. However, Foxp2 is also a so-called transcription factor, something that controls the activities of other genes. <br> <br> “The Foxp2 mouse can now be used to determine which genes are abnormally expressed [activated] in the cerebellum in these animals,” said Buxbaum. “Those genes might be legitimate autism-susceptibility genes.”</font></p> <p><font face="Arial" size="2">* * *</font></p> </b> </body>