Figure 1. RT-PCR analysis of trans-splicing involving exons from the mod(mdg4) anti-sense region 1. (A) Scheme showing the organization of the mod(mdg4) locus of D. melanogaster based on data from FlyBase and our experimental data in S2 cells. The exons included in the anti-sense region 1 are indicated. (B) The effect of depleting individual SWI/SNF subunits on the abundance of mod(mdg4) anti-sense exons measured by microarray hybridization (data from Moshkin et al.³²). (C) RT-PCR analysis of trans-spliced transcripts that include exons from the anti-sense region 1. A forward primer complementary to the common exon 4 (F in Fig. 1A) was combined with different reverse primers complementary to different anti-sense exons, as indicated above each lane, and used to amplify specific transcripts using cDNA prepared from S2 cells. The RT-PCR products labeled with letters in the figure were purified and sequenced, and their exon composition is shown in (D). As expected, all the products contain the common exon plus at least one anti-sense exon.