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Human Language Gene Changes How Mice Squeak
archatheist writes "Researchers at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany have engineered a mouse whose FOXP2 gene has been swapped out for a different (human) version. This is interesting because the gene is implicated in human language, and this has changed how mice squeak. '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. Dr. Enard argues that putting significant human genes into mice is the only feasible way of exploring the essential differences between people and chimps, our closest living relatives.' The academic paper was published in Cell."
Hasn't that been done already ?
http://video.google.com/videoplay?docid=-4860483760049380308
The linked article seems to disagree with you:
Stanford University's Irving Weissman has injected human neural stem cells from aborted fetuses into the brains of fetal mice, where they have integrated and grown into human neurons and glia that intermingle with mouse brain cells, making up about 1 percent of the tissue in their brains.
Today's biology is finite component analysis done at a massive scale.. Figuring out how a machine as big as a person works is going to take millennium
Maybe not, high-throughput molecular biology is getting better all the time.
-With the genome sequenced we have a rough idea of how many genes there are and can find homologies between genes, so you can begin clustering genes by presumed function.
-With mutagenesis screens, you can sometimes identify most of the genes involved in a given process.
-High-throughput protein interaction studies can identify complexes, grouping proteins into functional groups.
-There's an attempt to make a knockout mouse for every gene in their genome.
None of those will give you the full story for any one gene, nor will any give you good stories for most of the genes by themselves. But used together, we can have a rough idea of what genes do what, and can take a closer look at what we need to. This gene, FOXP2 for example, was not chosen at random.
And that's just with technology I've heard of that exists now. I don't know much about genomics, and we certainly are going to continue to invent ways to get research done faster. I think the human genome project came in under budget and ahead of schedule largely due to technology that was advanced as the project was underway. It's too early to make such long forecasts.
TF(academic)A is a very well done piece of work. I'm glad to see this, as opposed to the junior high school comprehension level press releases usually presented as science. As such, my criticisms are offered respectfully.
The FOXP2 gene cannot be said to be directly involved in language. The referenced works state that altering it disrupts some aspects of language production. There are many more ways that disruptions can occur through third variables or more general systems. In this case, altering the gene causes alteration in the dopamine system, which feeds the spiny neurons. Dopaminergic activity on spiny neurons causes inhibitory signals in the gamma range (~40 HZ) to be sent to the neurons in Hebbian cellular assemblies (a primary processing unit), synchronizing them and causing them to perform their function. This may well happen in the basal ganglia, but also happens over much of the cortex. This is a general system, responsible for a great deal of brain function. To claim it is part of language is not wrong, but is improper in that it is inaccurate due to over-specificity. As evidence, the well studied dopaminergic disorder Parkinson's does cause language disruption as noted in TFA, but clearly does so only as a specific example of a global phenomenon.
Similarly, specific changes due to specific allele substitutions can only be said to be true if and only if substituting other alleles into the same locations do not cause similar changes. There is no evidence that the example referenced is as specific as is implied by the statement as presented.
The statement that studying mice as 'the only feasible way' to study the relationship between humans and chimps appears so skewed that I wonder if it is a misstatement or misinterpretation. In any case, direct comparison studies have been done with excellent results. My old boss at NIH did volumetric comparisons on chimps brains using MRI, looking for left/right asymmetry in the language areas. In all of a dozen or so cases, he found it, to a degree similar to that in humans. In all but one cases, the left was greater than the right, also as found in humans. The one exception is not a difference, but rather a supporting similarity. The language centers are usually on the left because they are usually contralateral to the dominant hand, usually the right. In a dozen or so humans, chances are one or so will be left handed, with language centers on the right, just as was seen in the chimps. Studying mice is certainly fruitful and the results may well generalize to primate comparison studies. But to say it's the only feasible way to compare primate data is very wrong.
"I may be synthetic, but I'm not stupid." -- Bishop 341-B