Fig. 4.

Functional analysis of Plasmodium berghei protein phosphatase 5 (PbPP5) during sexual development. (A) Gametocytemia of wild type (WT) and Δpbpp5 parasites at day 3 p.i. (B) Male/female gametocyte ratios of WT and Δpbpp5 parasites at day 3 p.i. (C) Absence of ookinete formation in the Δpbpp5 parasites. The conversion rate is the percentage of Pbs21-positive parasites (stained by anti-Pbs21 monoclonal antibody) that had successfully differentiated into elongated ‘banana-shaped’ ookinetes. (D) Absence of oocysts in midguts of mosquitoes infected with Δpbpp5 k1 parasites compared with WT at day 10 post feeding. Circles correspond to oocyte numbers in individual mosquitoes. The panel represents one of the two or more infections performed with three infected mice per parasite clone and per infection. The number of mosquitoes analyzed per infection: WT, n = 29, 26, 39; Δpbpp5 k1, n = 33, 36, 40. (E) The formation of macrogametes. (F) The interaction of Δpbpp5 male gametes with red blood cells (exflagellation centers). Results were obtained from five independent experiments for the comparison between the WT and Δpbpp5 parasites. Two infected mice were analyzed per parasite clone. (G) The interaction of Δpbpp5 male gametes with female gametes. (H) Ookinete conversion after crossing Δpbpp5 parasites with Δp47 and Δp45/48 parasites. For all experiments, WT parasites were used as the control and three mice were used for each group. Results were obtained from at least two independent experiments. n.s., not significant; *, P<0.05; **, P<0.01; ***, P<0.001.