Şempanzelerdeki eski virüs DNA’sı, insan ve şempanze beyinlerinin nasıl ayrıştığını açıklamaya yardımcı olabilir

Human brains are about three times larger than chimpanzee brains, even though most protein-coding genes in the two species are very similar. Lund University neuroscientist Johan Jakobsson and his colleagues turned to the parts of the genome that control when genes are switched on, reporting on 23 October in Science Advances. Their focus was an endogenous retrovirus, a genetic leftover from an infection in an African ape ancestor 5 to 7 million years ago. This viral DNA sits at 158 sites in the chimpanzee genome but is absent in humans, for unknown reasons. When the team used CRISPR to cut it out of chimpanzee stem cells, a neighbouring gene, LINC00662, became active, as it normally is in human brain cells. Its activity was in turn linked to stronger activity in genes that may matter for neural development and connections. Jakobsson suggests the insertion may have helped the two brains diverge, though other genetic and environmental factors may also contribute.