Description of the mathematical model for ploidy profile dynamics.
(A) Kinetic scheme describing the sequential reaction of endoreduplication. k2i and γ2i denote the rate constant of endoreduplication from 2iC to 2i+1C cells and the removal constant of cells from the 2iC population, respectively (1 ≤ i ≤ 5). b indicates the rate constant of mitotic cell division of 2C cells. This scheme could be simplified in this case as given by a single constant rate of endoreduplication k in time. (B) Time evolution of the probability of each ploidy obtained by the analytical solution with k = 0.5. (C) Parameter dependency for optimizing a ploidy profile with the mathematical model. Color-coded RSS values with various parameter combinations are shown. The white dotted line indicates a minimum RSS in a combination of the parameters k and t. The color bar is scaled from minimum to maximum in this diagram. (D) Valley-like dynamics of the relationship between t and RSS with k = 0.5. The RSS reached the minimum when t = 2.27. (E) Based on the relationship between t and RSS with k = 0.5, an optimized ploidy profile was obtained using t = 2.27. The probability distribution of each ploidy level from the experimentally measured data (Exp.), the mathematically modeled data at t = 2.27 (mod.), and the Poisson distribution (Poi.) are indicated. The probabilities of 2C (green), 4C (blue), 8C (orange), 16C (red), and 32C (black) are shown.