Coupled alternative splicing detected by heaviest bundling. Genomic sequence (top) is shown as exons (filled boxes) and splices (angled lines; alternative splices are colored red). The alignment of mRNAs and ESTs is shown schematically by alignment intervals (horizontal lines); the ends of each expressed sequence are indicated with vertical lines. The isoforms produced from the alignment data by the algorithm are shown at the bottom. Adjacent ESTs (and isoforms) are colored differently to make it easier to distinguish them. (A) In Hs.193788, two nonadjacent alternative splices (skipping of exons 24 and 26) were always observed together (in two ESTs), thus, the algorithm coupled both events in a single isoform (isoform 1). (B) An example of alternative initiation.
