A team of scientists studying cell division developed a special light microscopy system and used it to analyze the molecular density of cellular environments. Their results provide a novel insight into mitotic chromosome condensation in living human cells. Their work is published in the journal Proceedings of the National Academy of Sciences ( PNAS ) on August 27, 2024.
To carry out their study, the team developed an orientation-independent-differential interference contrast (OI-DIC) microscopy system combined with a confocal laser scanning microscope capable of precisely mapping optical path differences and estimating molecular densities. Mitotic chromosome condensation is an essential process for transmitting replicated chromosomes to two daughter cells during cell division. To study the underlying physical principles of this process, we investigated whether depletion attraction, a force that attracts large structures in crowded cell environments, is involved in this process.
" Shiori Iida, Genome Dynamics Laboratory, National Institute of Genetics In the chromosome condensation process, chromatin strands are compacted into short chromosomes. This process makes the chromosomes rigid to resist the pulling force from the spindle. While several proteins involved in the condensation process, including condensins and topoisomerase IIα, have been identified and extensively investigated, physical bases of the condensation process remain unclear.
"Using newly developed special ligh.