Great apes reveal surprises in their DNA 🧬

Scientists have identified sequences in great apes' DNA capable of forming unconventional structures called non-B DNA. These configurations appear to play a key role in regulating cellular processes and genome evolution. Repetitive regions of the genome, long inaccessible, are now being analyzed thanks to advanced sequencing technologies.


A research team used complete, telomere-to-telomere genome assemblies to predict the location of these structures. This data allows the study of previously unexplored areas due to their repetitive nature. The results, published in Nucleic Acids Research, show a high concentration of non-B DNA in these newly sequenced regions.

Non-B DNA structures include forms like G-quadruplexes and Z-DNA, associated with specific cellular functions. Their presence in key areas such as telomeres and centromeres suggests a role in chromosomal stability. The gorilla genome, particularly rich in repetitive DNA, also exhibits more potential motifs for these structures.

These discoveries could shed light on mechanisms involved in genetic diseases and certain cancers. For example, a chromosomal translocation linked to Down syndrome shows a high concentration of Z-DNA at its breakpoint. This indicates a possible involvement of non-B structures in chromosomal rearrangements.

Researchers have experimentally validated the formation of some of these structures, but most require further investigation. Cellular and genomic context likely influences their appearance and function. This study paves the way for a better understanding of DNA structural diversity and its impact on biology.

Why are great ape genomes so important?

Great apes share much of their DNA with humans, making them valuable models for studying human evolution and diseases. Their genomes contain similar repetitive regions, which were difficult to analyze until recently.

Complete telomere-to-telomere assemblies offer an unprecedented view of these areas. They reveal differences and similarities in the distribution of non-B DNA structures between species.

This comparison helps understand how these structures evolved and what functions they might have. It also sheds light on general mechanisms of genome evolution in primates.