CDPK1- parasites are viable during erythrocytic development.

(A) Schematic of PbCDPK1 knockout strategy using homologous recombination. (B) Southern hybridization, using a probe indicated in blue, demonstrates replacement of the PbCDPK1 locus. (C) RT-PCR demonstrates the loss of PbCDPK1 expression in CDPK1- parasites. PbCDPK1 and GAPDH control transcripts were amplified from genomic DNA from WT parasites, from cDNA of WT erythrocytic stages, from cDNA of CDPK1- erythrocytic stages or from water as negative control. (D) CDPK1- erythrocytic stage parasites have a growth rate similar to wildtype in vivo, as determined by daily monitoring of parasitemia of infected mice.