(A) Single-cell state transition trajectories of sgf73Δ from the data (16O cells, 93 in Path 1, 67 in Path 2) (left), and from stochastic simulations (right). (B) The lifespans of two aging paths in sgf73Δ from experimental data (red and blue solid circles) and from simulations (red and blue curves). Dashed curves are the WT lifespans from Figure. 1F for comparison. (C) Age-dependent state distributions of S1’, S1, S2 and S0 and Death in sgf73Δ. Solid circles represent the experimental data. Solid curves represent simulated results averaged from 50 simulations with the shaded areas showing the standard deviations of simulations. (D) Cross-path switching frequency in WT and sgf73Δ, calculated as a percentage of the total number of cells. Solid bars represent experimental data, with error bars indicating expected standard deviation (details see Method, Computational Modeling). Open bars represent simulations, with error bars indicating standard deviation of 50 simulations. p< 0.001 for both paths with two-sample t-test. See also Table S1, Figures S4, S6, S9 and S10. (E) Schematic diagram illustrates the effects of Sgf73 at specific state transition steps.