Russia has grown an artificial brain to study genetic mutations

Employees of the Institute of Cytology and Genetics (ICIG) of the Siberian Branch of the Russian Academy of Sciences have grown organoids identical to human brain tissue to study the genetic causes of mental retardation.

The scientists found that failures in neurogenesis at an early stage of fetal development that lead to mental retardation can be linked to mutations in the CNTN6 gene.

"The fact that large mutations lead to dramatic consequences led us to think that there may be functionally significant elements of the genome within the gene that influence the course of neurogenesis and that we should focus on studying," commented ICIG associate researcher Tatiana Schneider.

Scientists have focused on the parts of the genome known as HAR-elements (from the English Human accelerated regions). They began to study them only in recent years, and it has already been established that they have not undergone special changes throughout the evolution of vertebrates. But in humans, these regions began to change with great speed. Most HARs are enhancers, that is, they stimulate gene activity, and are located near genes that regulate early development, including the brain. HAR elements may have been one of the mechanisms of brain evolution that led to the development of speech and abstract thinking in the ancestors of modern humans.

Two such elements are present in the CNTN6 gene. To study their role in human neurogenesis, the researchers removed from the genome of cells sections containing HAR, and grew from it cerebral 3D-organoids - three-dimensional tissues, which in structure are very close to brain tissue. The results showed that removing enhancer cells leads to abnormalities. Now the research team led by Tatiana Schneider wants to study in more detail the "switching off" of each element and its effect on the process of neurogenesis.