Fig. 2.

The four most proximal elements in the sequenced array from the XL telomere drawn approximately to scale. All elements are HeT-A, and each element is joined by its 3′ oligoA to its proximal neighbor. The most proximal element, HeT-A {}4,800, is complete, two elements are truncated in the 3′ UTR, and one element is truncated in the ORF. Elements are identified by FlyBase identifier number. Dark blue, 3′ UTR; light blue, ORF; magenta, 5′ UTR; white, string of Tags on the 5′ end of complete element {}4,800; gold, beginning of the subtelomere region; bent arrows, transcription start sites (each arrow indicates a cluster of three closely spaced sites at the 3' end of the element). The start site on {}5,504 initiates transcription of {}4,800, a transposition-competent element. Other starts will not produce productive transcripts. Physical mapping of BACs from this stock indicates that this telomere extends >100 kb further to the left (51), but no sequence is available.