Commitment to the production of male and female gametocytes in the human malaria parasite Plasmodium falciparum

Commitment to the production of female and male gametocytes was studied in the NF54 line of the human malaria parasite Plasmodium falciparum. The deve lopment of sibling parasites derived from individual schizonts was followed , and 2 antisera against the female gametocyte-specific protein Pfg377 and the male gametocyte-specific protein alpha -tubulin II were used to determi ne the sex of sibling gametocytes. The experiment showed that individual co horts of sibling gametocytes were stained in a mutually exclusive fashion b y only one or the other antiserum, indicating that individual schizonts com mitted to yield sexual parasite progeny produce gametocytes of the same sex . This work suggests that in P. falciparum commitment to sexual differentia tion occurs prior to schizont maturation, at the same moment when the sex o f the resulting gametocytes is determined.