Study on Genetics of Brain Growth and Complexity

 

Science reports on an interesting study into the genetics of brain growth and complexity:  

Now, a study identifies mutations that transform seemingly useless DNA sequences into potential genes by endowing their encoded RNA with the skill to escape the cell nucleus—a critical step toward becoming translated into a protein. The study’s authors highlight 74 human protein genes that appear to have arisen in this de novo way—more than half of which emerged after the human lineage branched off from chimpanzees. Some of these newcomer genes may have played a role in the evolution of our relatively large and complex brains. When added to mice, one made the rodent brains grow bigger and more humanlike, the authors report this week in Nature Ecology & Evolution.

....When Hu introduced one of these genes into mice, their brains also grew larger than normal and developed a bigger cortex, the wrinkly outer layer of the mammalian brain that in humans is responsible for high-level functions such as reasoning and language. The second gene did likewise in mice, and also caused the animals’ brains to develop more humanlike ridges and grooves. Those mice performed better on tests of cognitive function and memory than mice lacking this gene, the team says it will report soon in Advanced Science.

Overall, the findings suggest these de novo human genes “may have a role in brain development and may have been a driver of cognition during the evolution of humans,” says Erich Bornberg-Bauer, an evolutionary biophysicist at the University of Münster.  

Cheers, 

Colin