报告题目：Osmotic effects in cell density regulation, cell size and nucleus mechanics
报告人： Pierre Sens教授，法国国家科学研究中心、居里研究所（CNRS and Institut Curie, France）
报告时间：2024-11-21，下午14:00
报告地点：物理科技楼409
报告摘要：The size and density of living cells are the result of passive physical constraints and active biological processes. Their interplay leads to the appearance of robust and ubiquitous scaling laws relating linearly cell size, dry mass, and nuclear size. One remarkable feature is that the protein density within a cell remains constant during cell growth.
I will discuss how the different scaling laws can be explained quantitatively by a single model of size regulation based on three simple, yet generic, physical constraints - osmotic balance, hydrostatic balance, and electro-neutrality - defining the “the Pump-Leak model” (PLM). I will show how cell density homeostasis can be understood by coupling the PLM with a simple model of gene expression. I will then extend this analysis to the cell nucleus and discuss factors that can influence to nuclear to cell (N/C) volume ratio, and discuss how cell mechanics may modify the different scaling law. If time permits, I will end with the interesting case of fresh-water single celled organisms, which need specific mechanisms to deal with acute osmotic challenges.
报告人简介：Pierre Sens is research director at CNRS and group leader at Institute Curie, in Paris. Pierre received his PhD from the University of Strasbourg (France) in 1996 in the field of soft condensed matter and complex fluids. He then was a postdoc at U.C. Santa Barbara (Material Research Lab) for a couple of years, then at Institute Weizmann (Dept. of surfaces and interfaces) in Israel for a year, before coming back to France with the CNRS. Dr. Sens is a theoretical physicist applying physical concepts to the study of biological systems, in particular to living cells. His research interests include the active mechanics of cells (cell motility, tissue mechanics and mechano-sensation), cellular membranes, self-organisation in non-equilibrium systems with application to cellular organelles, and cellular homeostasis such as cell volume and density regulation.
