Asymmetric Segregation of Damaged Cellular Components in Spatially Structured Multicellular Organisms
Different colors correspond to different damage levels. In each time step of the computational model, a cell is selected at random. The cell has a probability of going apoptotic, given by its damage level , in which case another random cell, with damage level , proliferates to replace it. If the selected cell does not go apoptotic, it remains in the cell population unchanged. The probability that the mitochondrial genome has acquired additional damage since the last cell division is . The daughter cells therefore have a probability of inheriting a damage level of and a probability of inheriting additional damage. This may be distributed symmetrically, with both cells receiving damage, or it may be segregated asymmetrically, leading to one cell with a damage level of and one with a damage level of . We define one time unit of the simulation to be time steps, such that, on average, each cell is selected once per time unit.