Figure 1

Generation of Δpcrmp3 and Δpcrmp4 parasites. A. Transfection of P. berghei parasites with constructs PL1082 or PL1083 containing the tgdhfr gene flanked by target sequences for homologous recombination within the pbcrmb3 or 4 loci generated Δpcrmp3 a and b and Δpcrmp4 a and b respectively. Fragment sizes produced by restriction enzyme digestion are shown in kb. X, Xho1; K, Kpn1; H, HindIII; S, StuI; E, EcoR1, B, BamH1. B. Southern blots of genomic DNA from WT and Δpcrmp3 or 4 clones digested with enzymes indicated were hybridized with specific probes within the 5' target region of pcrmp3 or 4. C. Chromosome analysis of Δpcrmp3 and 4 parasite clones. Chromosomes were hybridized to probes specific for the P. berghei dhfr/ts 3'UTR region or for tgdhfr within the selection cassette, as indicated. The pbdhfr/ts probe hybridizes to the P. berghei dhfr/ts gene on chromosome 7. Both probes hybridize to the site of integration of constructs PL1082 in the pbcrmp3 locus on chromosome 6 in Δpcrmp3 or the site of integration of PL1083 in the pbcrmp4 locus on chromosome 13 in Δpcrmp4.