|ZFIN ID: ZDB-PUB-090716-26|
The Molecular Structures and Expression Patterns of Zebrafish Troponin I Genes
Fu, C.Y., Lee, H.C., and Tsai, H.J.
|Source:||Gene expression patterns : GEP 9(5): 348-356 (Journal)|
|Registered Authors:||Tsai, Huai-Jen|
|Keywords:||Zebrafish, Troponin I, Muscle, Expression pattern, Molecular structure|
|PubMed:||19602390 Full text @ Gene Expr. Patterns|
Fu, C.Y., Lee, H.C., and Tsai, H.J. (2009) The Molecular Structures and Expression Patterns of Zebrafish Troponin I Genes. Gene expression patterns : GEP. 9(5):348-356.
ABSTRACTTroponin I (TnnI), a constituent of the troponin complex located on the thin filament, provides a calcium-sensitive switch for striated muscle contraction. Cardiac TnnI is, therefore, a highly sensitive and specific marker of myocardial injury in acute coronary syndromes. The TnnI gene, which has been identified in birds and mammals, encodes the isoforms expressed in cardiac muscle, fast skeletal muscle and slow skeletal muscle. However, very little is known about the TnnI gene in lower vertebrates. Here, we cloned and characterized the molecular structures and expression patterns of three types of zebrafish TnnI genes: tnni1, tnni2 and tnni-HC (heart and craniofacial). Based on the unrooted radial gene tree analysis of the TnnI gene among vertebrates, the zebrafish TnnI1 and TnnI2 we cloned were homologous of the slow muscle TnnI1 and fast muscle TnnI2 of other vertebrates, respectively. In addition, reverse transcription-polymerase chain reaction (RT-PCR) and whole-mount in situ hybridization demonstrated that zebrafish tnni1 and tnni2 transcripts were not detectable in the somites until 16 hours post-fertilization (hpf), after which they were identified as slow- and fast-muscle-specific, respectively. Interestingly,tnni-HC, a novel TnnI isoform of zebrafish was expressed exclusively in heart during early cardiogenesis at 16 hpf, but then extended its expression in craniofacial muscle after 48 hpf. Thus, using zebrafish as our system model, it is suggested that the results, as noted above, may provide more insight into the molecular structure and expression patterns of the lower vertebrate TnnI gene.