Figure 3: The LCR architecture in Hymenopteran and Daphnian Dscam.

(a) A schematic diagram of the partial pre-mRNA in the Hymenopteran species. Constitutive exons are depicted as black boxes, alternative exons as green boxes and introns as lines. Above are sequences of consensus intronic elements for different species taxa (see Supplementary Table S1 for abbreviations). The most identical nucleotides at each position are shown in different colours. Notably, most of these differences are structurally silent, whereas nucleotide covariations that maintain the structural integrity of the dsRNA were shaded in red. (b) The predicted tetramer architecture and secondary structures of the A. mellifera pre-mRNA. Mutations were introduced into four dsRNAs (M1–M8). (c) Effects of RNA secondary structures were validated by disruptive mutations (M1–M8) and compensatory double mutations (M12, M34, M56 and M78). WT, wild-type. (d) The monomer architecture and secondary structure of D. magna Dscam pre-mRNA. Mutations were introduced into dsRNA (CM1, CM2). (e) Effects of RNA secondary structure were validated by disruptive mutations (CM1, CM2) and compensatory double mutations (CM12). WT, wild-type. Data are expressed as mean±s.d. from three independent experiments.