Figure 1

Molecular phylogenetic analysis of the troponin T protein family. Bayesian methodology based upon the alignment trimmed (this included removal of both ends, plus some sites in the middle with large insertions in one or a small subset of sequences) as shown in additional file 5. Values adjacent to nodes indicate posterior probabilities. Some inferred groupings are boxed in grey, labelled to the right of the figure and with supporting value in bold. The vertebrate sequences fall into three groups reflecting the well-characterised TnT1, TnT2 and TnT3 genes, with a fourth group (labelled Fish TnT1/2) containing only bony fish sequences, the relationship of which to other TnT groups cannot be determined. The B. schlosseri (BsTnT-c, black highlighted) sequence falls into a group of ascidian sequences. Note that another ascidian, H. roretzi (Hr), has two TnT protein, and the B. schlosseri sequence is most closely related to the adult (HrTnT-a) one. Protostome sequences have been used to root the tree, as TnT genes have not been identified outside the bilateria. The positioning of echinoderm (S. purpuratus; Sp) and amphioxus (B. floridae; Bfl) sequences reflects the likely phylogenetic relationships of these taxa. Accession numbers of sequences are shown in brackets adjacent to the protein name (^(*) and ^(°) are downloaded from HGSC and JGI database respectively, all the others are from GenBank). Other abbreviations: -a, adult; -e, embryonic; -l, larval; Am, Apis mellifera; Bf, Bufo marinus; Bm, Bombyx mori; Bt, Bos taurus; Ci, Ciona intestinalis; Cj, Coturnix japonica; Cn, Chlamys nipponensis; CspI, Capitella sp. I; Dm, D. melanogaster; Dp, Daphnia pulex; Dr, Danio rerio; Fc, Felis catus; Gg, Gallus gallus; Gm, Gadus morhua; Hc, Hyla chrysoscelis; Hq, Haemaphysalis qinghaiensis; Hro, Helobdella robusta; Mm, Mus musculus; Mt, Mitu tomentosa; Oc, Oryctolagus cuniculus; Rn, Rattus norvegicus; Sa, Sparus aurata; Ss, Salmo salar; St, Salmo trutta; Xl, Xenopus laevis.