Fig. 5: PfFBXO1 is essential for IMC biogenesis and gametocyte maturation.

A Representative IFA of a stage III gametocyte showing the effect of PfFBXO1 depletion on SPMTs (anti-alpha-Tubulin) and IMC (anti-PfGAP45). Scale bar = 2 µm. B U-ExM of PfFBXO1-deficient parasites showing dysmorphic IMC and SPMTs compared to controls. Insets highlight the reduced PfGAP45 and tubulin staining at one of the ends of a stage III gametocyte. C U-ExM image of a stage III gametocyte showing absence of IMC sutures and broken membranes visualized by NHS ester and BODIPY-TR Ceramide staining in rapamycin treated parasites compared to the uniform membrane staining and distinct IMC-sutures in controls. Arrowheads show the presence of IMC plates. Scale bar = 10 µm for (B, C). D Area-plot showing the progression of gametocytogenesis and gametocyte maturation. The values plotted are number of gametocytes at a given stage on the specified days after induction, determined by manual counting of 50–100 high power fields of Hemacolor-stained smears from two biological replicates. Mean values are plotted with error bars representing the standard deviation. Representative image of the staging is provided as an index. Scale bar = 2 µm. E Scatterplot quantifying the morphological abnormality observed in the rapamycin treated PfFBXO1-deficient gametocytes based on their shape. A roundness score of 1 indicates a perfectly round or spherical structure. Bars represent the median value with the 95% CI. The quantification was performed on 3 technical replicates each, in two separate induction experiments (biological replicates). Shown here is the result from one biological replicate. Significance is calculated using unpaired t-test with Welch’s correction.