Fig. 1.

(a) Diagrams of the left-hand telomeric fragment of chromosome 7 and the var2csa locus on the left-hand telomeric fragment of chromosome 12 in wild-type E8B clonal parasites and in their clonal progeny CS2 following ectopic recombination between chromosome 7 and chromosome 12. The filled bar indicates wild-type chromosome 12, and the unfilled bar indicates the sequence from chromosome 7 introduced following recombination. Positions are indicated for TARE 1–5, TARE 6 (rep20), the second telomere-associated repeat sequence from subtelomeric block 2 (SB2-2),⁷ several members of the rif and var multigene families, and the restriction sites AccI (A), EcoRI (E), HindIII (H), PvuII (P), XbaI (X), SalI (S), and PstI (Ps). The positions of probes used for Southern and Northern blots and regions that were directly sequenced are indicated beneath the diagrams. (b) Southern blots of CS2 and E8B gDNA digested with the enzymes indicated above the figure and separated by conventional gels (AccI, HindIII, and XbaI) and PFGE (XbaI, PvuII, and EcoRI) were probed with sequence from the 3′ end of var2csa exon 1. (c) Southern blots of PFGE-separated chromosomes probed with sequence from the 3′ ends of var2csa and It4_var44. (d) Southern blots of CS2 and E8B gDNA digested with the enzymes indicated above the figure were probed with sequence from the 3′ end of It4_var8 exon 1.