RESEARCH IN THE LAB
Mechanical understanding of
Cell division and Development
How cell 'reads' the environment and designs its architecture?
Our body consists of cells. The cell is the minimal unit of the life. A living organism can be made of a single cell. The cell consists of chemical substances, such as proteins. However, the cell is not just a mixture of chemical substances. The cell can live because these materials position themselves at right place at right timing. Just as appropriate furniture are positioned appropriately in a comfortable house, and people and goods move dynamically in a lively city, the cell functions as nano-scale molecules move and position appropriately. The cell is thus a living architecture.
Mechanical modeling of cell division
How is the cell constructed from small molecules? Construction of the cell is not lead by any superviser and there is no direct blueprint. To obtain insight into this mystery, our lab is examining whether we can reconstruct dynamic spatial organization of the cell from molecules activities using computer simulation. We are focusing on the process of cell division, in which one cell divides to make two daughter cells, a most fundamental and dynamic processes of the cell. We have succeeded to reproduce the migration of the cell nucleus toward the cell center, and the segregation of chromosomes, and cytokinesis with our simulations, and analyzing the underlying molecular activities. These studies revealed that, in addition to the active forces produced by molecular motors, passive forces generated as a by-product of active forces plays important role in intracellular organization.
Scaling inside the cell
The appearance of the cell is diverse. For example, neuron has long protrusions and oocyte is very large. To accomplish basic cell function, such as cell division, cellular architectures must have ability to ‘read’ the environment, with which the architectures adjust their sizes and shapes according to the size of the others. Our lab has been studying how physical parameters inside the cell (e.g. the sizes of the cell and organelles) affect the interior organization of the cells. Scaling in cellular architecture, in which the size of intracellular organelles is proportional to the size of the cell or other structures, is a major “order” inside the cell. We are studying the centration of the centrosomes, the size of mitotic spindle, and the size and mobility of chromosomes in the C. elegans embryo as models to investigate the mechanism underlying relative scaling inside the cell. We are focusing on the process of early embryogenesis, in which the size of the cells changes dramatically.
