Fig. 4

The exon-intron structure of five pairs of representative sibling paralogs and the domain organization of their proteins. The schematic diagram showed five types of underlying mechanisms responsible for structure divergence of F-box gene paralogs: exon/intron gain/loss (a), intron region substantial elongation (b), exonization/pseudoexonization (c), exon-intron boundary change (d), and exon split (e). The frequency of genes that underwent the corresponding mechanism was shown for F-box paralogs from C. elegans and C. briggsae. The color in the schematic diagram represented sequence similarity, and the numbers above or below indicate the DNA sequence length in corresponding regions