Normal gametocyte production. Activation of female gametocytes normal. Male exflagellation, however, strongly reduced. Flagella stained with an anti-tubulin antibody remain curled within the gametocyte body. Motility of male free gametes strongly impaired.

Ablation of PbSR-MG also resulted in fewer oocysts per mosquito host. To test if this difference solely reflected the defect in exflagellation, we repeated the mosquito infection using equal numbers of in vitro generated ookinetes. Despite exposing mosquitoes to equal infective load, we still observed a significant difference in oocyst numbers in PbSR-MG KO compared to wild-type parental parasites.