Figure 3.

The effect of deletions on PWSPX-dependent silencing. (A) Structure of deleted transgenes. P[UZP1Δ] is derived from P[UZP1] and contains a 740-bp deletion of the region around SNRPN exon 1. P[UZP2Δ] is derived from P[UZP2] and contains a 2.4-kb deletion leaving the 740-bp region around SNRPN exon 1. P[UZPPΔ] is derived from P[UZP2Δ] and contains a 215-bp deletion of the SNRPN promoter region. (B) Quantitative determination of lacZ expression in transgenic larvae carrying deleted constructs. Relative β-gal activity is shown in the presence (+) or absence (−) of GAL4. The depicted values are mean values for all strains analyzed (s, number of strains). Error bars indicate the SD, and P values were determined by the t test.