A human differs from a monkey by transcription factors
The superiority of the human brain ensures the control of genesRIA News
The superiority of human thinking abilities over the brain capabilities of our closest "relatives" – chimpanzees, provides, first of all, control over the work of thousands of genes in brain tissues, and not the presence of unique genes in human DNA, the authors of the study published in the journal Proceedings of the National Academy of Sciences are sure.
This discovery serves as an additional explanation for the fact that, having more than 97% of the genes shared with chimpanzees, a person is not only very different from these monkeys in appearance, but also has significantly greater mental abilities.
Scientists have found that differences in 90 proteins responsible for regulating the work of DNA in brain tissue cells affect the work of about one thousand different genes encoding certain proteins.
Scientists already knew that in the human brain proteins that perform transport functions or are involved in metabolic processes are synthesized much more actively than in the chimpanzee brain. It was believed that such increased activity of proteins is necessary for the transport and maintenance of a larger brain, but until recently, scientists were unclear how such work of proteins in the brain is coordinated.
In their work, the scientists tracked the work of genes encoding protein synthesis in the brains of six humans and five chimpanzees, as a result of which they were able to identify 90 proteins regulating the work of DNA, the activity of which affects the work of one thousand genes involved in the synthesis of other proteins. At the same time, the genes whose work these proteins regulate are identical in humans and monkeys.
Proteins that regulate the work of DNA are called transcription factors, since their activity affects the process of DNA transcription – reading information from it and using this data for the synthesis of new proteins.
The most numerous among these 90 regulatory proteins were proteins from the KRAB-ZNF family, which have the greatest number of changes in their structure, compared with this group in chimpanzees.
"Among these proteins that influence the work of DNA, humans have many unique ones formed as a result of the doubling of old genes, which have received completely new functions due to this, or have significantly accelerated their work in the human body. We believe that this group of genes is largely responsible for the uniqueness of our species," said Lisa Stubbs, lead author of the study, professor at the University of Illinois, quoted by the press service of the educational institution.
Having constructed diagrams reflecting the correspondence of certain transcription factors of gene activity in the cells of chimpanzee and human brain tissues, scientists saw that they are generally very similar, except for the position of several proteins that affect the work of DNA. These changes during the transition from chimpanzees to humans can be greatly enhanced by the work of other genes, which as a result leads to visible differences between species.
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