PfVps45 plays a crucial role in IMC biogenesis. (D) IFA of PfVps45 KS parasites ±rapalog (11 hours). IMC biogenesis is inhibited in parasites when Vps45 is mis-localized. GAPM2, parasite IMC; DAPI, nuclei. Scale bar =5 mm. (E) IFA of PfVps45 KS parasites ± rapalog (11 hours). Schizont plasma membrane fails to engulf merozoites when Vps45 is mis-localized. MSP1, parasite plasma membrane; DAPI, nuclei. An arrowhead points to fully formed merozoites with engulfed plasma membrane in wild-type conditions. Scale bar=5 mm. (F) Electron micrographs (TEM) of ± rapalog-treated Vps45 KS parasites (47 to 53 hpi). Early treatment at the ring stage (0 to 6 hpi) with rapalog leads to arrest of the parasites in the trophozoite stage. Later treatment at the early schizont stage (36 to 42 hpi) leads to a partial IMC biogenesis defect. IMC biogenesis initiates but failed to elongate (right inset). White arrowheads show IMC, while the red arrowhead shows endocytic vesicles. Scale bars =1 mm. (G) Schizonts formed in the presence of rapalog possess an enlarged residual body and smaller merozoites (right inset). Scale bar =1 mm. (H) Quantification of the size of merozoites formed in the presence or absence of rapalog. Bars show the SD.

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