"Speech" gene may encode a protein helps the brain mesh

[GoodGame]

As reported in Science (http://news.sciencemag.org/sciencenow/2011/07/language-protein-may-help-build-.html),

a gene FOX2, long thought to be crucial to the language ability in humans and animals may actually play a role in encouraging developing neurons to connect together.

Evidence of how it functions in a developing individual shows it at least has a regulatory role in the genome, turning a large number of genes on to affect neuron shape.

Most studies of FOXP2 have focused on its effects post-birth, says Simon Fisher, a neurogeneticist at the Max Planck Institute for Psycholinguistics in Nijmegen, Netherlands. So scientists have been unclear about its role in very early brain building.

To tease this out, Fisher and colleagues turned to embryonic mice. The team screened thousands of known genes in whole mice brains, looking for those switched on or off by the FOXP2 protein. In brain tissue bathed in high concentrations of FOXP2, the protein kicked about 160 genes into gear. Another 180 genes in these cells slowed down protein production. All of this suggests that FOXP2 is a "hub in a network of genes which might be important," Fisher says.

FOXP2 casts a wide net and also disproportionately oversees genes involved in brain cell organization and growth, most notably the growth of neuronal neurites, appendages that reach out to other neurons. In fact, many neurons in the brains of mice lacking functional FOXP2 proteins had noticeably stubbier appendages, Fisher's team reports online today in PLoS Genetics.

Such appendage stretching could be critical for learning. Early brain cells tend to chat with too many other neurons initially, explains Peter Carlsson, a developmental biologist at the University of Gothenburg in Sweden, who was not involved with the study. But when animals learn, those excess limbs get lopped off until only a few critical connections remain. Without FOXP2, it's possible that "you have less starting material for that pruning or adaptation," he says.

Pretty neat how the geometry of your cells can be so important to your ability to function!


A nice side video lecture:


Link to video.

 

[Nick Carpathia]

That makes sense, we know the brain is a neural network (by definition), and it's the connections that are needed to process information. It's consistent with the observation that children learn languages faster, maybe some aspect of the high number of interconnections of developing brains, there's evidence that overexpressing or silencing Foxp2 expression in birds corresponds to enhanced or decreased learning of audio.

It's definitely an interesting story, primates develop more connections, causing increased plasticity, enhancing learning. Now all we need to do is work out what inputs to single cells cause what effects on connections, and integrate all the different layers into a consistent model. Haha, we're not even close.

In addition, I wouldn't be surprised if Foxp2 dips its helical little fingers into a hundred different pies.

 

[emzie]

Foxp2 is my favourite gene in show casing just how small changes in a genome can have massive impacts. The human version (and Neanderthals too!) is two base pairs different than that of a mouse. It's one base pair different than a chimp.

In addition, I wouldn't be surprised if Foxp2 dips its helical little fingers into a hundred different pies.

I'd be surprised if it didn't have functions all across the body. IIRC, knock-out mice die without a copy.

 

[Nick Carpathia]

Huh, didn't know that. What could they die of? The paper I found simply describes motor abnormalities, no idea what causes them to just keel over. Mice are pretty fragile, but whatever effect seems pretty systemic.

 

[emzie]

Huh, didn't know that. What could they die of? The paper I found simply describes motor abnormalities, no idea what causes them to just keel over. Mice are pretty fragile, but whatever effect seems pretty systemic.

According to wiki, their lungs don't properly develop and they die within a few weeks of being born.

It gets back to one of my pet peeves in genetics, describing a gene as "for" something, as if there's only one gene for one thing, or that gene is limited to that one thing.

 

[GoodGame]

According to wiki, their lungs don't properly develop and they die within a few weeks of being born.

It gets back to one of my pet peeves in genetics, describing a gene as "for" something, as if there's only one gene for one thing, or that gene is limited to that one thing.

It's sort of a problem of how the gene is discovered. There's both "forward genetics" and "backward genetics", with the one being about starting from the phenotype and trying to locate that trait to a gene; of course they might not find a discrete gene but a regulatory gene that runs a cascade of effects. Or they might just find one genetic part of a larger quantitative trait (which may/may not involve special regulation).

But yeah it might be better to say a gene locus is associated with a trait rather than "for" a trait. Except that it is popular to believe that most traits are simple and discrete genetically, since the general population isn't studied on how complicated gene regulation is.

EDIT: Sorry if I'm preaching to the choir.

 

[Nick Carpathia]

I still love Proktor Zakarov's quote about the relationship between genes and morphology. As wacky as some of some of AC's science is, they at least got that bit better than the rest of the mass media.

 

[r_rolo1]

Yup, good ol'Provost quote should be stated in the beginning of every gene-related quote in the Media ( and of some Biology related courses, to be honest ... )

 

[MCdread]

Foxp2 is my favourite gene in show casing just how small changes in a genome can have massive impacts. The human version (and Neanderthals too!) is two base pairs different than that of a mouse. It's one base pair different than a chimp.

To be fair though, and while this doesn't affect your general point, the phenotypic differences could also be, at least partly, due to differences in the sequence of the target gene(s).

 

[GoodGame]

I still love Proktor Zakarov's quote about the relationship between genes and morphology. As wacky as some of some of AC's science is, they at least got that bit better than the rest of the mass media.

This one?

"Remember, genes are not blueprints. This means you can't, for example, insert "the genes for an elephant's trunk" into a giraffe and get a giraffe with a trunk. There are no genes for trunks. What you can do with genes is chemistry, since DNA codes for chemicals."
—Academician Prokhor Zakharov, Sid Meier's Alpha Centauri

I find it kind of wacky personally, since obviously genes do effectively code for morphology among other things (e.g. homeobox genes). And they effectively are blueprint, but true that it is a blueprint for big signal cascade of miscellaneous macromolecules.

 

[emzie]

I figured he meant the fractal quote...

The genetic code does not, and cannot, specify the nature and position of every capillary in the body or every neuron in the brain. What it can do is describe the underlying fractal pattern which creates them.