Sanjay Jain (University of Delhi; SFI External Professor)
Abstract. What sets the scale of the size of bacterial cells and the scale of fluctuations of cell size of genetically identical bacteria in a fixed environment? The talk will discuss the possible origin of these two scales, as well the origin of a time scale — the doubling time of cells. Phenotypic variation in genetically identical cells is generally believed to be a consequence of environmental variations or stochasticity in gene expression due to the small number of molecules involved. Another source of phenotypic variation will be described — the first passage time for a molecular population to cross a fixed threshold in growing cells. In the context of a generic class of mathematical models of cells it will be shown how this time scale and its fluctuations set the average size of cells and the fluctuations of size.