Man surpasses chimpanzees and other monkeys in brain size and number of neurons due to differences in the nature of the work of the ZEB2 gene and other DNA areas that control the transformation of the stem cells of the nervous system, according to British biologists, reads an article published by the scientific journal Cell, Report informs.
To uncover the genetic mechanism driving these differences, the researchers compared gene expression - which genes are turned on and off - in the human brain organoids versus the other apes.
They identified differences in a gene called 'ZEB2', which was turned on sooner in gorilla brain organoids than in the human organoids.
To test the effects of the gene in gorilla progenitor cells, they delayed the effects of ZEB2. This slowed the maturation of the progenitor cells, making the gorilla brain organoids develop more similarly to human - slower and larger.
Conversely, turning on the ZEB2 gene sooner in human progenitor cells promoted premature transition in human organoids, so that they developed more like ape organoids.