A recent Yale study has provided new insights into the genetic changes that shaped human brain evolution, revealing how genetic regulators known as Human Accelerated Regions (HARs) control brain development and neurological disorders like autism and schizophrenia.
Researchers mapped nearly all HAR interactions to understand their role in shaping the human brain. Unlike previous research, which suggested that HARs regulated entirely different genes in humans compared to chimpanzees, this study found that HARs fine-tune the activity of genes already shared by both species.
Using advanced techniques, scientists were able to track how HARs interact with genes and neural stem cells, identifying gene targets for nearly all HARs. This discovery greatly expands our understanding of how genetic changes arose during evolution to make humans uniquely human.
The study’s findings suggest that many HAR gene targets are active in the developing human brain, influencing processes such as neuron formation and communication. Some of these genes are also associated with conditions like autism and schizophrenia, highlighting the potential role of HARs in shaping normal brain function and neurological disorders.
This breakthrough research opens up new avenues for understanding how genetic changes contributed to the evolution of the human brain, according to Yale Professor James Noonan. The study’s results reveal that HARs largely regulate the same genes in both humans and chimpanzees, but adjust gene expression levels differently in humans, suggesting evolutionary changes emerged through modifying existing genetic pathways rather than creating new ones.
The discovery adds to our growing understanding of how genetic changes made us human and significantly advances knowledge about what genes HARs controlled. With nearly 90% of all HAR gene targets identified, this study provides a more complete picture of the biological changes that HARs may have driven, allowing researchers to explore new avenues for brain evolution research.
Source: https://scitechdaily.com/yale-scientists-just-cracked-the-dna-code-that-built-the-human-brain