Human Brain Gene Not Present In Chimps

BrainPeteLinforth / Pixabay

The specific gene is not present in chimps, and allowed for a dramatic rise in the number of neurons in a crucial brain region. The gene has only been discovered in modern humans, Neanderthals and Denisovans, another branch of extinct humans, writes Tia Ghose for Live Science.

Human brain: Increasing number of neurons

Scientists now believe that the gene allows the neocortex to contain a greater number of neurons, laying the foundations for the expansion of the human brain relative to chimpanzees.

“It is so cool that one tiny gene alone may suffice to affect the phenotype of the stem cells, which contributed the most to the expansion of the neocortex,” claimed Marta Florio, lead author of the study and a doctoral candidate in molecular and cellular biology and genetics at the Max Planck Institute of Molecular Cell Biology and Genetics in Dresden, Germany.

Florio and her team discovered that the gene, known as ARHGAP11B, is highly activated in human neural progenitor cells, but is found at all in mouse cells. The section of DNA is only 804 genetic bases long, making it a tiny but crucial fragment.

Laboratory tests on mice

It was once part of a longer gene but was somehow duplicated and later put into the human genome. In order to test their theory the scientists inserted the DNA snippet into the brains of mice, and sure enough those mice with the additional DNA seemingly developed larger neocortex regions.

The fact that Neanderthals and Denisovans also had this gene, and chimpanzees do not, would seem to suggest that the gene emerged soon after we separated from chimpanzees.

Florio was quick to acknowledge that the gene is probably not the only genetic differentiation which makes the human brain special, and predicts that there are probably many more that we still have not discovered.

The study was published on Thursday in the journal Science.



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Brendan Byrne
While studying economics, Brendan found himself comfortably falling down the rabbit hole of restaurant work, ultimately opening a consulting business and working as a private wine buyer. On a whim, he moved to China, and in his first week following a triumphant pub quiz victory, he found himself bleeding on the floor based on his arrogance. The same man who put him there offered him a job lecturing for the University of Wales in various sister universities throughout the Middle Kingdom. While primarily lecturing in descriptive and comparative statistics, Brendan simultaneously earned an Msc in Banking and International Finance from the University of Wales-Bangor. He's presently doing something he hates, respecting French people. Well, two, his wife and her mother in the lovely town of Antigua, Guatemala. To contact Brendan or give him an exclusive, please contact him at theflask@gmail.com