− この都医学研セミナーは終了しました。 −
国立遺伝学研究所 構造遺伝学研究センター 生体高分子研究室 教授
|世話人||正井 久雄 （東京都医学総合研究所 副所長）|
How is the long strand of genomic DNA organized in the cell? Recent studies have suggested that chromatin forms numerous domains as functional units of the genome. However, questions remain how they form, are distributed, and behave in living cells. Here, by combining super-resolution imaging photoactivated localization microscopy and single nucleosome tracking, we developed a novel nuclear imaging system that allowed us to visualize the spatial organization of chromatin domains along with their dynamics in living mammalian cells. We have clearly demonstrated the quantitative relations between the epigenetic state and dynamics: more heterochromatic regions show less chromatin movement. With cell differentiation, the domains became more apparent with reduced dynamics. Furthermore, various perturbation experiments indicated that they are organized by many factors, including electrostatic force and molecular crowding as well as cohesin complex and nucleosome-nucleosome interactions. Notably, we observed the chromatin domains during mitosis, suggesting that they act as Lego blocks of chromosomes to retain epigenetic information throughout the cell cycle.
Maeshima, K., Ide, S., Hibino, K., Sasai, M. Liquid-like behavior of chromatin.
Current Opinion in Genetics and Development. (2016) 37:36–45.