Scientists reveal mechanism behind evolution of brain folds regulated by ancient gene

The findings were recently published in Nature Genetics.The human brain is covered with intricate wrinkles and grooves, which constitute one of the important biological foundations for the emergence of advanced human cognitive functions.

The traditional view holds that the expansion of the primate cerebral cortex was primarily driven by newly evolved genes.However, a research team led by Shi Lei, a researcher from the Kunming Institute of Zoology under the Chinese Academy of Sciences, proposed an alternative possibility: certain ancient and highly conserved genes could also play a key role in human brain evolution by reshaping their expression levels through changes in regulatory elements.The….

They found that an ancient gene called "CCNB1IP1" was already expressed in the brain of the tree shrew, a close relative of primates, long before primates emerged but at relatively low expression levels.The team further discovered that during the following course of evolution, the expression level of this ancient gene showed a clear stepwise increase among tree shrews, marmosets, macaques and humans, reaching its highest level in the human brain."The….

In macaques, whose brains have folds, the expression level is markedly elevated.

In the human brain, this gene is expressed at the highest level.Moreover, the team identified a key regulatory sequence, CRE1, that drives the elevated expression of CCNB1IP1.To verify the gene's function, the team constructed a mouse model carrying the gene.

The experiment showed that mice, which normally have a smooth cerebral cortex, developed cortical folding structures after the gene knock-in.

Meanwhile, the modified mice exhibited enhanced learning and memory abilities in behavioral tests.The team noted that this study not only provides a new perspective for understanding the evolution of the human brain, but also offers new clues for exploring the causes of neural development disorders.

Scientists reveal mechanism behind evolution of brain folds regulated by ancient gene Xinhua | Updated 1 minute ago | Brain wrinkles and grooves support advanced cognition, traditionally thought to result from newly evolved genes.