Strategies for Identifying RNA Splicing Regulatory Motifs and Predicting Alternative Splicing Events
Figure 2
Selection of Splice Patterns of Known Alternative Exons
Selection of splice patterns of known alternative exons of Tra, Sxl, and Dscam genes in D. melanogaster [3,4], and α-Actinin, α-Tropomyosin, Troponin-T, and PTB in H. sapiens [71]. Exon skipping is the predominant AS event in many metazoans and, e.g., has been shown to be involved in tissue- and developmental stage–specific regulation, as well as autoregulation (PTB) [72]. AS products of pre-mRNAs expressed from Tra and Sxl genes are involved in the pathway of somatic sex fate in D. melanogaster, which is regulated by altogether five AS genes at the top of the determination cascade [4]. The “master gene” Sxl is expressed in female flies, where it acts as a negative regulator of splicing. AS of the Dscam gene is known for its theoretically large number of possible different AS products (∼38,000 against ∼14,000 D. melanogaster protein-coding genes), which are derived from four clusters of skipped exons. The regulation of one cluster includes so-called selector-docking sites, which are inverse complementary overlapping sites located in the most 5′-end intron (docking) and upstream of each skipped exon (selector) of this cluster, respectively [73].