Figure 1.

Structure of the 3.3-kb Tag1 Element.

The ends of the element are defined by the 22-bp TIRs (closed triangles). STRs of the element are shown as closed boxes. The 5′ STR includes nucleotides 23 to 261, which ends at the start of transcription (bent arrow). The 3′ STR (nucleotides 2975 to 3273) begins after the stop codon and extends to the 3′ TIR. Interior to the STRs is the Tag1 coding region, which contains the large ORF (open boxes) interspersed with introns (horizontal lines); the hatched box indicates the 5′ untranslated region. In the expanded views of the STRs, each region containing a distinct repeated sequence is indicated by an arrow. Bars beneath the expanded views indicate the STR probes; the bars above refer to the probes described in Figure 4.