Fig. 4.

The isoleucine refractory point coincides with the transition into S-phase. a The isoleucine refractory point occurs after establishment of the New Permeability Pathway (NPP). The logistic models fit to the data predict the t50 point for sorbitol treatment to be significantly earlier than the isoleucine refractory point (vertical broken lines). b The isoleucine refractory point occurs after PTEX-dependent arrest point. Synchronous early rings were incubated in trimethoprim (TMP) to preserve PTEX translocon function and transferred to medium lacking TMP at the indicated times to inhibit PTEX function. Logistic regression models show hpi-dependent increase in relative growth, though the t50 for TMP withdrawal is earlier than the isoleucine refractory point. c The isoleucine refractory point overlaps with transition into S-phase. Parasitaemia in isoleucine lacking medium and the proportion of parasites with > 1C DNA content, increase with time. Note that the t₅₀ values overlap. When both hours post invasion (hpi) and > 1C DNA content are treated as factors in a model of growth in the absence of extracellular isoleucine, DNA content alone predicts relative growth (p < 5.38 × 10⁻¹²). d The t₅₀ point for the transition to > 2C DNA content occurs after the isoleucine refractory point. See Additional file 1: Table S1 for all regression summaries