Figure 2

Structure of the synapsin proteins domains and synapsin genes in representative metazoan phyla. A: A multialignment of synapsin proteins corresponding to the bordering exons containing the introns encoding for TIMP sequences. Identical residues in all sequences are shown in black. Residues identical to the human sequences were indicated in red. B: Conservation of exon-to-protein domain correspondence. The contribution of individual exons or groups of two exons to the C-domain sequence is indicated by colored boxes. The black boxes indicate the contribution of first and last exons to the A- and E-domains. The white exons correspond to the highly divergent sequences of the B-domain and region between C and E domains. The grey box indicates that Nematostella lacks of a true comparable A domain. The orthologous exons found in all species are shown by the same color (an asterisk inside the box indicates when the length of exon differs from those of humans), whereas the blue boxes indicate when an invertebrate exon is split in two separate exons in humans. Solid lines and dotted lines represent identical intron locations and intron locations differing only for 5-18 bp, respectively. The base-pair length of each exon is indicated inside the boxes. The numbers above the colored boxes represent the exon numbering. Bracketed red numbers correspond to the common intron phase; the different intron phase is indicated by bracketed black numbers. Intron position encoding TIMP sequences is indicated by a red arrow. The diagram is not drawn to scale. See text for further details.