Closing the Arabidopsis Genome Sequence: Researchers Bridge the Final Gaps

Researchers have filled the remaining gaps in the Arabidopsis thaliana genome sequence, providing insights into the organization and regulation of ribosomal RNA genes. The study identified over 70 gene subtypes located in specific regions of the nucleolus organizer regions (NORs) and found that one NOR is mostly silenced in growing plants, while the other NOR accounts for most ribosomal RNA gene activity in its central region. The findings shed light on the epigenetic control and evolution of NORs and have broad biomedical relevance for understanding gene regulation in other species.