Phylogenetic tree and gene structures of the spiggin multi-gene family and its homologs. Threespine and ninespine stickleback spiggin genes from the genome sequence (Gaac_spg1, 3, 4, 5, and 7; boxed), published spiggin cDNA sequences (spg1-spg4, Pungitius_spgα-γ; DDBJ/EMBL/NCBI accession numbers: AB221477, AB221481-83, DQ018713-8), and spiggin homologs in four other fish species (Tetraodon, spotted green pufferfish; Takifugu, torafugu; Oryzias, medaka; Danio, zebrafish) were subjected to phylogenetic analyses, and the resulting ML tree is shown. Numbers at nodes in internal branches indicate % bootstrap values (500 replicates). Putative corresponding relationships between genome and cDNA sequences are indicated by circles. The exon-intron structures of the corresponding genes are shown on the right. Brackets indicate the region used for phylogenetic studies (exons 7–16). The gene structure of spiggin cDNA sequences is shown in gray. Shaded boxes in the cDNA sequences indicate that the ORF could not be estimated from the genome data. Unpublished sequence gaps from ninespine stickleback genes and an undetermined region in the medaka genome are indicated by dotted lines. Asterisks in the zebrafish gene structure indicate the parts incongruent for the determination of ORFs because of indels.