Figure 3.

(a) Number of cells carrying no mutation in compartments 1–31 arising from compartment 1 containing 1000 cells. Lines show equation (2.3), with parameters n₀ = 1000, ε = 0.85, γ = 1.26, u = 10⁻⁶ and r₀ = 1/400. Cells are more likely to differentiate than to self-renew and thus progressively travel into more committed compartments. Initially, the cell count increases, but cells get washed out in the long run. The time scale is determined by the number of stem cell divisions. A stem cell is assumed to divide once a year, thus after 400 stem cell divisions a year has passed. (b) Count of cells carrying 0–3 mutations in compartment 31, given by equation (2.4). We used the same parameters as in (a). Cells carrying multiple mutations are exponentially suppressed. (Online version in colour.)