Gamete Egress in Activated Malaria Gametocytes

Gamete egress from the RBC was used as a proxy for activation as previously described (14 (link)). RFP-expressing gametocytes were activated in ookinete culture medium for 15 min at room temperature in the presence or absence of 1 mg/mL of MG1 or ScrMG1 peptides. Egress was determined by quantifying the number of RFP-expressing P. berghei 820cl1m1cl1 female gametes not enclosed in RBC membrane, as detected with an Fluorescein isothiocyanate (FITC)-conjugated anti-Ter-119 antibody (Miltenyi Biotec). Male gamete exflagellation was measured by light microscopy to determine the effect of the peptides on male gametocyte activation. Aphidicolin-inhibited exflagellation did not affect egress of the male gamete from the RBC detected by labeling the RBC membrane-associated cytoskeleton with an anti-spectrin antibody (Sigma) (Fig. 1B).