Ancient Viral Remnants Found to Influence Early Human Development
A significant portion of the human genome, roughly 8%, comprises genetic material derived from ancient viruses that integrated into our DNA over evolutionary timescales. While previously dismissed as “junk” DNA, these viral remnants – housed within transposable elements (TEs), often referred to as “jumping genes” due to their ability to replicate and relocate within the genome – are now recognized as potentially vital for early human development and evolutionary adaptation, according to a new study published July 18 in Science Advances.
Researchers from an international collaboration used genomic sequencing techniques to identify previously unrecognized patterns embedded within TEs. These patterns appear crucial for gene regulation, the intricate process governing when and how genes are activated or deactivated. “Although our genome has been sequenced extensively, much of its functionality remains elusive,” explained Dr. Fumitaka Inoue, an associate professor in functional genomics at Kyoto University, who co-authored the study. “Transposable elements’ contributions to genome evolution are becoming increasingly apparent.”
Understanding how these TEs influence gene expression holds promise for advancements in several areas. Researchers believe it could illuminate their role in human evolution, uncover potential links between TEs and disease development, or even inform new gene therapy approaches targeting specific functional sequences.
The integration of ancient viral genetic material into the genomes of primate ancestors occurred through replication and insertion events within chromosomal structures. “These ancient viruses effectively invaded our ancestral genomes, and their residues now constitute a substantial part of our own,” noted Dr. Lin He, a molecular biologist at UC Berkeley, who was not directly involved in the research. “Over time, some viruses are eliminated, others suppressed, and yet others are repurposed to serve essential functions within the human genome.”
The repetitive nature of TEs has historically presented challenges for researchers seeking to accurately categorize and analyze them; incomplete documentation can impede evolutionary and functional analyses. In this study, scientists focused on MER11 sequences, common across primate genomes, developing a new classification system that led to the identification of four previously unknown subfamilies.
