For many years, scientists thought that much of this human DNA was a worthless mess—calling it “junk”—because they thought it had no real function. This misunderstanding clouded the very important issue that these non-coding regions account for about 98.5% of the human genome. Recent research has begun to shift this narrative, revealing that the so-called “junk DNA” plays a crucial role in gene regulation and may have far-reaching implications for understanding human evolution and neurological disorders.
Curiously enough, only about 1.5% of the human genome consists of protein-coding genes. These genes have a major influence on realizing distinct characteristics for phenotypes, including eye color, height, and hair texture. The rest of our so-called junk regions, formerly scoffed at, are now understood to be critical in regulating how and when our genes are expressed. That realization is currently revolutionizing the study of genetics. Specifically, it’s concerned with the ways in which brain development will shape brain vulnerability to disease.
The Significance of Non-Coding DNA
Emerging evidence is showing that these non-coding DNA regions are critical for regulating how, when and where our genes get turned on and off. These non-coding regions play important roles in regulating biological processes, such as early development, growth, proliferation, and differentiation. Research conducted by Johan Jakobsson, a professor at the Department of Experimental Medical Science, highlights these non-coding elements’ pivotal role in brain development.
Jakobsson’s group at Lund University studies LINE-1 (L1) transposons. These transposable elements are confined to the non-coding, or junk, regions of the genome. Research using induced pluripotent stem cells and brain organoids has recently uncovered remarkable information. These litigious, palm-sized analogues of the human brain, cultivated in controlled environments, further our understanding of cognitive activity.
These results indicate that LINE-1 retrotransposons are an important mediator of cis-acting transcriptional control in human pluripotent stem cells. They play critical roles in regulating early brain development. This underscores the important role of non-coding DNA in creating pathways that lead to human cognition.
Collaborative Research Initiatives
Jakobsson heads the research team and will be following up with further investigation. They’re doing it inside the ASAP (Aligning Science Across Parkinson’s) Collaborative Research Network. This initiative focuses on understanding the role of transposable elements across a wide spectrum of brain diseases, with special emphasis on neurodegenerative diseases.
To do this, the team works closely with collaborators in China and Europe and uses cells derived from patients along with donated samples of brain tissue. This comprehensive strategy fosters their appreciation of how these genetic factors mediate brain pathology. Researchers are uncovering the role that LINE-1 transposons play in mediating other non-coding regions’ interactions. Ultimately, they hope to find new ways to target the mechanisms responsible for brain diseases.
Implications for Understanding Human Evolution and Disease
The revelations about non-coding DNA and LINE-1 transposons have huge ramifications for evolutionary biology and medicine alike. The renewed focus on these regions’ roles has shifted attention to their contribution to regulation of nearby genes—an essential process for the execution of healthy neural development. This knowledge will help us make strides in understanding genetic predispositions to brain disorders ranging from autism to schizophrenia.
Clearly, scientists are learning more about the immense complexity of the human genome on a daily basis. Their findings underscore the important role that non-coding DNA plays in shaping evolutionary processes. Creating new pathways for change Jakobsson’s team did formative research. Their research could result in innovative therapeutic approaches to treating or preventing neurological diseases by focusing on genetic factors that have largely been ignored.