Mutant/mutation
The mutant lacks expression of Phosphoenolpyruvate carboxylase (PEPC) and expresses GFP under control of a male and RFP under control of a female gametocyte specific promoter..

Protein (function)
Phosphoenolpyruvate carboxylase (PEPC) is involved in carbon metabolism. Carbon dioxide (CO2) is thought to be essential for the growth of intraerythrocytic malaria parasites in order to synthesize pyrimidine through CO2 fixation and to regulate the intracellular pH of the parasite. PEPC is thought to catalyse CO2 fixation with phosphoeno/pyruvate in the absence of pyruvate carboxylase in Plasmodium and thereby supplying the cytosol with oxaloacetate (OAA) [34]. P. falciparum mutants lacking expression of PEPC showed a strong reduction in growth of trophozoites and mutants could only be selected by supplying additional malate to cultures of the blood stages (Storm, J and Müller, S, 2010. Malaria Journal 9 (Suppl 2): P49).

Phenotype
Phenotype analyses indicate that PEPC is not essential for blood stage development, both for asexual stages and for gametocytes.

(Strongly) reduced gametocyte-, ookinete- and oocyst production. No formation of sporozoites.

Additional information
The growth of the pepc- mutant was compromised compared to wild type parasites, as the pepc- mutant, but not the mdh- mutant was overgrown by the wt parasite in an in vivo sensitive single host competitive growth assay. The number of merozoites observed in mature schizont stages was similar to wt.  Scrutiny of the growth phenotype detected in the pepc- mutants showed that they have a prolonged asexual cycle (4 h longer than wt). The number of gametocytes formed in blood stages was  reduced in pepc- mutants by almost 50% with no notable difference in male to female ratio. Further phenotypic analyses showed reduction of exflagellation (pepc- mutants 84% less than wt. Ookinete development in in vitro cultures of pepc- mutants was also severely affected.

Other mutants