Disruption of the pfeik1 gene does not affect asexual growth rate. Representative cycles of pfeik1-parasites and the parental 3D7 strain (dashed). Cycle points were semi-automatically collected fixed and stored at 4°C every 30 min over ~4 days. After permeabilization and RNAse treatment, the DNA content was analyzed by flow cytometry as previously described . Mature schizonts (~16–32 N), red line; S-phase (~2–8 N), blue line; G1-phase (1N), black line. Percentage values as a function of time are shown; hpi: hours post-infection, referring to the mature schizont maxima as zero.