A novel alternative splice domain in zebrafish tenascin-C

We have identified and sequenced clones from a zebrafish library that correspond to tenascin-C (TN-C). The 2036-bp sequence covers the C-terminal segment of the protein. Comparison of this sequence to TN-C from other vertebrates indicates that our sequence starts in FN-III domain 5, continues with one alternative splice domain, then with FN-III domains 6-8 and, finally, the complete fibrinogen-like domain. The alternative splice domain, designated TNfnQ, is not closely identified to any of the domains in other species, and may represent a novel descendent of the alternative splice-domain precursor.