Conditional excision of pffrm2 disrupts apicoplast segregation and causes a severe fitness defect. IFA showing loss of PfFRM2-HA staining (green) upon RAP treatment. Levels of PfACT1-staining (red) do not change. Loss of protein was ~90% (averaged from 3 independent experiments) as determined by Western blot (Figure 4D) was confirmed by IFA, which indicated a loss of protein in ~95% parasites (N=350). G. Apicoplast staining (red) is affected to various degrees – collapsed, intermediate and apparently normal in RAP-treated parasites as compared to DMSO controls, where a normal punctate staining for apicoplasts is visible in a multi-nucleated schizont. The number of parasites with normally segregated apicoplasts was significantly reduced, with a high percentage of cells showing collapsed or morphologically aberrant apicoplasts.

Felix Stortz J, Del Rosario M, Singer M, Wilkes JM, Meissner M, Das S. Formin-2 drives polymerisation of actin filaments enabling segregation of apicoplasts and cytokinesis in Plasmodium falciparum. Elife. 2019 8. pii: E49030