Targeted gene truncation of KAHRP. (A) Schematic representations of the plasmid vector pHH1 used for integration, the endogenous KAHRP gene, and the expected integration event. Promoter (arrow) and terminator (T) regions are depicted as shaded, the resistance marker human DHFR (hDHFR) in white, the endogenous KAHRP gene in gray, and the truncated KAHRP gene in black boxes. Relevant restriction enzyme sites are shown and sizes of each expected fragment are shown below in kilobases. (B) Southern blot analysis of Afl II-HindIII-digested gDNA from 1 to 8 of: 3D7-K119, -K245, -K362, -K405, -K530, -K589, -K(re), and 3D7 parental parasite lines. Note that for 3D7-K119, the construct does not have the second AflII site in the truncated KAHRP gene. Therefore, there is no 1.45-kb band present on the blot but a band representing the distance between the first Afl II site and the HindIII site. For 3D7-K245 the band happens to be a very similar size to the 4.088-kb band and therefore only one double band is visible for this mutant cell line.