Abstract
In eukaryotic cells, the genomic DNA is hierarchically organized into chromatin. Chromatin structures and dynamics influence all nuclear functions that are guided by DNA, and thus regulate gene expression. Chromatin structure aberrations cause various health issues, such as cancer, lifestyle-related diseases, mental disorders, infertility, congenital diseases, and infectious diseases. Many studies have unveiled the fundamental features and the heterogeneity of the nucleosome, which is the basic repeating unit of chromatin. The nucleosome is the highly conserved primary chromatin architecture in eukaryotes, but it also has structural versatility. Therefore, analyses of these primary chromatin structures will clarify the higher-order chromatin architecture. This review focuses on structural and functional studies of nucleosomes, based on our research accomplishments.