Figure 3

Southern blot data supports the continuity of PkH_051981 and distal exons of the 205 SICAvar gene, and the presence of an intron of about 12 kb between exons 2 and 3. A. Schematic depicting a tentative restriction map covering 35 kb surrounding the 205 SICAvar locus, based on the premise that the PkH_051981 and distal exons of the 205 SICAvar gene were contiguous in the genome. The predicted position of the redefined 12-exon 205 SICAvar gene is noted (blue boxes). The predicted sizes of the various restriction fragments are noted by colour-coded bars, without the size of sequence gaps taken into consideration. The position of the two probes used consecutively in the Southern blot shown below in Figure 3B, are labelled. The presence of two gaps, referring to unresolved sequence in the genome database, are indicated downstream of the position of each probe. B. Southern blot. P. knowlesi [Pk1(A+)] gDNA restriction enzyme digests were hybridized consecutively with probes representing the second exon of PkH_051981 (shown) and exon 4 (not shown). Arrows point to fragments that were visualized with both probes, as would be expected, in support of the continuity of these sequences in the genome. The enzymes used were Ban II (B2), Eco RV (E5), Hind III (H3), Hpa I (Hp1), and Nci I (N1). The expected sizes of Hind III, Hpa I, and Nci I are exceeded by about 13, 9, and 8.5 kb, respectively (Figure 3A and Table 3), supporting the presence of a large intron of close to 12 kb.