Mutant ferrets offer clues to human brain size
By inactivating a gene linked to abnormally small brain size in humans, researchers have created the first ferret with a neurological mutation. Although the original impetus of the work was to study human brain disease and development, says Howard Hughes Medical Institute (HHMI) Investigator Christopher Walsh, the results also shed light on how the human brain expanded during the course of evolution.
[...] Walsh, Bae, and their colleagues discovered that their ferrets model human microcephaly much more accurately than do mice. The ferrets displayed severely shrunken brains, with up to 40 percent reduced brain weight. And, as in humans with the condition, cortical thickness and cell organization were preserved.
What's more, the ferrets reveal a possible mechanism for how human brains have grown over evolutionary time. Over the last seven million years, human brain size has tripled. Most of this expansion has occurred within the cerebral cortex. Indeed, in the mutant ferrets, researchers traced the cerebral cortex deficits to a type of stem cell called outer radial glial cells (ORGs). ORGs are created by stem cells capable of making all sorts of different cells in the cortex. Walsh's team found that Aspm [a gene linked to microcephaly in humans] regulates the timing of the transition between these stem cells and ORGs. This affects the ratio of ORGs to other types of cells. Thus, tweaking Aspm can actually dial up or down the number of nerve cells in the brain, Walsh says, without having to change many genes all at once.
Aspm knockout ferret reveals an evolutionary mechanism governing cerebral cortical size (DOI: 10.1038/s41586-018-0035-0) (DX)
(Score: 2) by MichaelDavidCrawford on Monday April 16 2018, @07:04PM
US federal taxes aren't due until _tomorrow_.
Yes I Have No Bananas. [gofundme.com]
(Score: 2) by Arik on Monday April 16 2018, @07:20PM (2 children)
I didn't know that ferrets, unique among all life forms on Earth, do not experience neurological mutation in the wild.
Actually, I still don't. Seems much more likely this is just wrong.
If laughter is the best medicine, who are the best doctors?
(Score: 2) by MostCynical on Monday April 16 2018, @10:22PM
Maybe "researchers have created, for the first time in a laboratory, a ferret with a neurological mutation."
Thee maybe thousands of mutant ferrets out there, but this one has a wonky brain because scientists madeit that way deliberately (or by accident, but who knows what they were trying to do - make a ferret play chess?)
"I guess once you start doubting, there's no end to it." -Batou, Ghost in the Shell: Stand Alone Complex
(Score: 2) by Dr Spin on Tuesday April 17 2018, @12:15PM
Mutant Ferrets with neurological conditions are rarely found in the wild - because they are typically elected to high office.
Warning: Opening your mouth may invalidate your brain!
(Score: 2) by meustrus on Monday April 16 2018, @09:16PM
If it's the reason this mutation made the ferrets' brains smaller, then it is not the reason human brains are larger. It sounds more like something we two species share in common.
Which is not to say that you couldn't make bigger-brained humans by tweaking this gene. Doesn't mean it has anything to do with human evolution, but you could probably make your own Khan Noonien Singh this way. I'm guessing that the reader knows why this is a Bad Idea.
If there isn't at least one reference or primary source, it's not +1 Informative. Maybe the underused +1 Interesting?