Journal: Journal of molecular evolution
Article Title: Early Divergence of the C-Terminal Variable Region of Troponin T via A Pair of Mutually Exclusive Alternatively Spliced Exons Followed by A Selective Fixation in Vertebrate Heart
doi: 10.1007/s00239-022-10075-z
Figure Lengend Snippet: The phylogenetic tree of amino acid sequences of exon 16 and exon 17 of representative vertebrate fast TnT genes and counterpart exons of vertebrate cardiac and slow TnT genes constructed with maximum-likelihood method using DNAStar MegAlign Pro software demonstrates their phylogenetic lineages with exons 10A and 10B of Drosophila TpnT gene as references. Gap penalty was set at 30. The numbers below the branches are percentage bootstrap values for the associated nodes. NA: No bootstrap value, indicating a poor support of the branch. The colors of fonts indicate exon 16-like (Blue), exon 17-like (Red), cardiac (Purple) and slow (Green) isoforms. The exon of vertebrate cardiac TnT gene that emerged from duplication of the fast skeletal muscle TnT gene (Chong and Jin 2009) shows closer relationship to the exon 17 of fast TnT gene, indicating the selective fixation of one of the inherited alternative exons in vertebrate heart, which was conserved in vertebrate slow TnT gene duplicated from the cardiac gene (Chong and Jin 2009). The pattern of divergence further indicates that this structure in cardiac TnT has diverged further while it is more conserved in slow TnT. Accession numbers of the sequences analyzed are listed in Supplement Table S2.
Article Snippet: Phylogenetic analysis Amino acid sequence alignments were done with DNAStar Lasergene MegAlign Pro software (Lasergene, Inc, Madison, WI) using ClustalW method.
Techniques: Construct, Software