Figure 5.

Mass dynamics of cell division: Twenty-eight division events were recorded from the treated and untreated populations in all experiments (from a total of ∼600 cells). (a) We determined the mass range of dividing cells by observing individual divisions and measuring the mass of the parent and daughter cells directly. Panel (a) compares the mass distribution of all cells measured (treated and untreated; dashed line) with the masses of those cells that divided during the experiment (red before the division, blue after division). (b) Surprisingly, a number of cell divisions were highly asymmetric, with ∼55% or more, of the total parent cell mass remaining in the larger of the two daughter cells. (c) Two examples of highly asymmetric division are shown over the 5-h time course. The smaller of the daughter cells in these divisions (indicated by an asterisk) contained 35% and 40%, respectively, of the parent cell mass. These division events are indicated by red-solid circles in (b). Error bars represent ±2% CV, our estimate of the measurement error (see Methods).