Are there genes that are "exclusively human"? asks Iddo Friedberg at Byte Size Biology. The human genome has been compared to those of great apes in an attempt to see which genes are shared and which make people different from their primate cousins, Friedberg says. A group of researchers from China and Canada is trying to answer the question of whether there are any genes in the human genome that are de novo, and are not homologous to any in apes. In a new paper published in PLoS Genetics, the team describes a research pipeline in which they scanned the human genome for genes with high similarity to chimp, orangutan, and rhesus macaque genes. They then took the genes that had mutations that rendered them functional only in humans, and looked to see if those genes were active by checking if they produced proteins. The researchers found that 60 de novo human genes are expressed in 11 human tissues, and that the testes and the cerebral cortex of humans have the highest expression of these genes, Friedberg says, adding, "This actually makes some sort of sense: the testes are hypothesized to be a hotbed (sorry…) of evolutionary novelty, with all the meiosis going on there. The high expression of the de novo human genes in the cerebral cortex also seems to confirm our anthropomorphic prejudice: we are smarter. Yay." And there may be even more de novo human genes that may explain the differences between humans and apes, the paper's authors add.
The Originality of Humans
Nov 22, 2011