Role of RNA secondary structures in regulating Dscam alternative splicing

Alternative splicing of mRNA precursors is a versatile mechanism of expanding proteomic diversity. The most striking example of this is the Drosophila melanogaster Down syndrome cell adhesion molecule (Dscam1) gene, which potentially encodes 38,016 distinct isoforms by mutually exclusive splicing. The genomic organization of Dscam1 is largely conserved across the pancrustaceans, although the number of splice isoforms varies from 2240 in the clam shrimp (Eulimnadia texana) to 121,104 in the whiteleg shrimp (Litopenaeus vannamei). RNA secondary structure plays a pivotal role in mutually exclusive splicing of Dscam1. Here, we review recent progress in the identification, evolution, and regulatory roles of RNA secondary structure in alternative splicing of Dscam1.