Figure 1

Multiple alignments and phylogenetic analysis of duplicated exon nucleotide sequences. (A, B) Multiple alignments of amino acid sequences of duplicated exon 3 (A) and exon 8 (B) sequences and their counterparts from orthologs in other species, respectively. The alternative exons are labeled 'a' and 'b' or 'c'. (C, D) Cladogram of insect duplicated exon DNA sequences and vertebrate orthologous constitutive exons corresponding to the alignments shown in (A, B). For each cluster, the amino acid sequences of each alternative exon from each species were aligned using the Clustal W program and phylogenetic trees generated. The branches contained the vertebrate constitutive exons (CSE), invertebrate alternative exons 8a or exons 3a, alternative exons 8b or exons 3b and alternative exons 8c, respectively. Abbreviations: Hsa, H. sapiens (NM_000746.3); Dre, D. rerio (NP_957513.1); Mmu, M. musculus (NP_031416.2); Gga, G. gallus (NP_989512.1); Tru, T. rubripes (CAG03274.1); Dme, D. melanogaster (CG4128) [16]; Aga, A. gambiae [17]; Bmo, B. mori (CH379590); Tca, T. castaneum (CM000280); Ame, A. mellifera [21].