(A) Analysis of 182 T. brucei telomere clones, 167 of which are categorized into BES sets by insert size, BES promoter, ESAG6, and VSG type. TAR clones were categorized into BES sets (first column) primarily according to their BES promoter sequence type (second column) (for sequence alignment, see Fig. 5A). A variable region of ESAG6 was also sequenced, and the ESAG6 sequence type is indicated (for sequence alignments, see Fig. 5B). Presence of several known VSGs (indicated in column 4) was analyzed by PCR (for primers, see Table 1). Clones marked in bold have the correct promoter, ESAG6 and, where indicated, VSG type for the BES set (column marked TAR clones). The average size in kilobases with standard deviant (±SD) for the different TAR clones is indicated. Different size classes form BES subsets, marked with A and B, and correspond to the presence or absence of duplicated BES promoters (see Fig. 1B). Clones marked with A and B were checked by PCR for ESAG10 to confirm that they indeed had a duplicated BES promoter as expected. Clones in the column marked TAR clones (mis) have either missing or different BES promoter, ESAG6 or VSG types or combinations of mismatches indicated. These clones were not included in the size estimations. Clones in the last row marked “uncharacterized clones”, could not be categorized due to the problems indicated. aNo VSG if expected; bESAG6 type different; cmissing promoter type; dmissing ESAG6 type; edifferent known VSG; fmissing, faint or too small (<20 kb) or multiple band on PFGE;, gpromoter, ESAG6 and VSG type not obtained; hpromoter sequence with one mismatch; and ipromoter sequence with multiple mismatches. (B) Size distribution of the T. brucei BES TAR clones analyzed. The different BES sets and VSG type if known are indicated below. The size of the individual TAR clones described in A is indicated in kilobases. Clones that have the correct promoter sequence, ESAG6 and VSG type (TAR clones marked in bold in panel A) are indicated with dark bars. TAR clones with mismatched sequences or VSG type (TAR clones [mis] in A) are indicated with white bars. Some BES sets fell into size classes differing by ∼13 kb, which are indicated with A and B. PCR for ESAG10 confirmed its presence in sets A and its absence in sets B which is compatible with the presence of a duplicated promoter in these BESs (Fig. 1B).
