Tena, a Drosophila gene related to tenascin, shows selective transcript localization

We report the identification and molecular characterization of tena*, a Drosophila gene located at 11A6-9 on the X-chromosome. The deduced protein of 782 amino acids contains eight tenascin-type EGF-like repeats not described in Drosophila before, but lacks the fibronectin type III repeats and the fibrinogen homology present in the vertebrate tenascin molecules. Tena codes for a large transcript which exhibits extremely long 5' and 3' untranslated regions. Tena transcripts show a specific perinuclear localization within cells and are mainly expressed in the central nervous system, in the brain and near muscle attachment sites during embryogenesis. During pupal stages, tena is detected in the eye. These expression patterns are reminiscent of those of vertebrate tenascin. Tenascin-type EGF-like sequences are also detected in other loci of Drosophila and in various other organisms, indicating the existence of a family of genes related to tenascin.