Schematic of the T. brucei BES promoter region between the 50-bp repeat arrays (hatched box) and the most upstream of the expression site associated genes (ESAG7). The top schematic of a VSG expression site is labeled according to Figure 1B, with the promoter indicated with a white flag. In the expanded section between the 50-bp repeat arrays and ESAG7, the primers used to PCR amplify the 560-bp TAR target fragment are indicated with arrows T1 and T2. The BES promoter is indicated with a dark arrow. Initial sequence characterization of the telomere clones obtained involved PCR amplification between S1 and S2, and subsequent sequencing of each strand of the PCR product using nested primers S3 and S4 (for primer used, see Table 1).
