Heterogeneity of Atlantic salmon troponin-I1The novel amino acid sequences published here are available under the accession Nos. U83878 (Atlantic salmon fast myotomal muscle troponin-I, isoform 1), U84393 (Atlantic salmon myotomal muscle troponin-I, isoform 2) and U84394 (Atlantic salmon myotomal muscle troponin-I, isoform 3).1

Three non-identical, full length troponin-I (Tn-I) clones were isolated from an Atlantic salmon myotomal (trunk) muscle cDNA library. The primary structures, which are predicted to range from 172 to 180 amino acids in length, exhibit similar percent identity scores when compared with fast, slow and cardiac specific Tn-Is from higher vertebrates. When the sequence data are considered along with the results of Western blotting it is evident that Tn-I is more heterogeneous in Atlantic salmon than has been previously shown in higher vertebrates.