Comparison of Growth Rates. Dictyostelium enters stationary phase at ~1–3 × 107 cells/ml, a point reached here after 4 days of growth. Wild-type, kif8-, kif10-, and kif11- cells exhibit very similar rates of logarithmic phase growth, with a doubling time in axenic medium of 8–9 hrs. Kif4- cells grow significantly more slowly than any of the three kinesin nulls as well as the wild-type control. Kif11- cells appear to delay their entry into stationary phase (96 hrs), but remain within the normal range of maximum cell density reported for Dictyostelium.