Detailed phenotyping of the exflagellation defect in NF54/MAP-2GFPDD parasites. Representative images of anti-α-tubulin IFAs showing axoneme formation 15 min after activation of gametogenesis. Protein stabilizing (+ Shield-1) and -degrading (− Shield-1) culturing conditions are compared. White arrowheads indicate incorporation of DNA into newly forming microgametes exclusively in parasites cultured under protein-stabilizing (+ Shield-1) conditions. Parasites were split (± Shield-1) 24 h before probing. Scale bar = 2 μm. However, in PfMAP-2GFPDD-depleted cells the axonemes remained bundled around the nucleus, nuclear DNA is not incorporated into the forming microgametes and no exflagellation is observed. In contrast, male gametocytes cultured in the presence of Shield-1 began to release motile microgametes into which DNA was incorporated. Immunofluorescence labelling with an α-tubulin antibody indicated that axoneme formation is also not affected in PfMAP-2GFPDD-depleted male gametocytes 15 min post-activation. However, in PfMAP-2GFPDD-depleted cells the axonemes remained bundled around the nucleus, nuclear DNA is not incorporated into the forming microgametes and no exflagellation is observed.

Hitz E, Balestra AC, Brochet M, Voss TS. PfMAP-2 is essential for male gametogenesis in the malaria parasite Plasmodium falciparum. Sci Rep. 2020 10(1):11930.