Researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, have now genetically engineered a strain of mice whose FOXP2 gene has been swapped out for the human version.
Keep in mind that this sort of thing is done all the time. Scientists "knock out" or replace genes in mice (creating what we call transgenic mice) in order to study the gene's function (basically, by eliminating the gene, we can guess what the gene does by comparing the transgenic mice with normal mice). So what's special about FOXP2?
..FOXP2, was identified in 1998 as the cause of a subtle speech defect in a large London family, half of whose members have difficulties with articulation and grammar. All those affected inherited a disrupted version of the gene from one parent. FOXP2 quickly attracted the attention of evolutionary biologists because other animals also possess the gene, and the human version differs significantly in its DNA sequence from those of mice and chimpanzees, just as might be expected for a gene sculpted by natural selection to play an important role in language.
So what happened when the researchers replaced the mouse's FOXP2 gene with the human version?
..the human version of FOXP2 does in fact change the sounds that mice use to communicate with other mice, as well as other aspects of brain function. In a region of the brain called the basal ganglia, known in people to be involved in language, the humanized mice grew nerve cells that had a more complex structure. Baby mice utter ultrasonic whistles when removed from their mothers. The humanized baby mice, when isolated, made whistles that had a slightly lower pitch, among other differences, Dr. Enard says.
However, don't expect to see talking mice or animals anytime soon.
..the study showed lots of small effects from the human FOXP2, which fit with the view that FOXP2 plays a vital role in language, probably with many other genes that remain to be discovered. “People shouldn’t think of this as the one language gene but as part of a broader cascade of genes,” he said. “It would have been truly spectacular if they had wound up with a talking mouse.”
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