Figure 5

Tenascin-W diversity is generated by duplications of a FN type III domain. A. The tenascin-W of Tetraodon nigroviridis is predicted to be encoded on 14 exons. The figure shows a schematic of the predicted protein's repeat and domain organization and the corresponding exons. The N-terminal linker is encoded on the first exon. The second exon encodes the heptad repeats and the EGF-like repeats. This is conserved in all of the tenascin-Ws illustrated here. FN type III domains 1, 2 and 4 are encoded on two exons, but the third FN type III domain is encoded on a single exon (shaded). The FReDs of all of the tenascin-Ws is encoded on five exons. B. The full-length predicted tenascin-W of Takifugu rubripes has five FN type III domains. The additional domain is the result of a duplication of the third FN type III domain, which is encoded on a single exon. C, D. The predicted tenascin-Ws of Danio rerio (C) and Gallus gallus (D) have 6 FN type III domains, the apparent consequence of an additional duplication of the third FN type III domain. E, F. In mouse (Mus) and man (Homo) the very large tenascin-W predicted proteins can also be explained by multiple duplications of the third FN type III domain. Note that the first FN type III domains of the pufferfish, but not the other tenascin-Ws, are encoded on two exons (black). The relative sizes of the exons and introns between the different genera are not shown to scale.