Identification, sequence structure and expression characteristics analysis of troponin genes of Siniperca chuatsi

【Objective】To explore the expression characteristics of troponin genes in the skeletal muscle growth and development of Siniperca chuatsi, to provide basic information for the study of the growth and development of S. chuatsi.【Method】Based on the joint analysis of S. chuatsi transcriptome data and genome data, troponin genes of S. chuatsi were screened and identified. Then bioinformatics analysis of the troponin was performed by online softwares such as BioEdit, ClustalW, MEGA 5.0, SWISS-MODEL and SMART. Real-time fluorescence quantitative PCR was also used to examine the expression specificity of troponin genes in different muscle tissues of S. chuatsi and their expression pattern in the skeletal muscle from 10 to 60 d(10-60 dph) after hatching. 【Result】A total of 11 troponin genes of S. chuatsi were identified: 3 TnnC genes(TnnC1a, TnnC1b and TnnC2), 5 TnnI genes(TnnI1a, TnnI1b, TnnI1c, TnnI1al and TnnI2), and 3 TnnT genes(TnnT1, TnnT2a and TnnT3a). They distributed on four chromosomes, with obvious differences in gene structure, binding sites and tertiary structure of protein. These genes were tissue-specific: TnnC1a gene was highly expressed in slow muscle, followed by cardiac muscle; TnnC1b gene was also highly expressed in slow muscle, and the TnnC1a and TnnC1b genes had a similar expression pattern in other types of muscle tissues except in cardiac muscle; TnnC2 gene was highly expressed in fast muscle and cheek; TnnI1a, TnnI1c and TnnI1al genes were highly expressed in slow muscle with similar expression patterns; TnnI1b gene was highly expressed in cardiac muscle and followed by slow muscle; TnnI2 gene was highly expressed in fast muscle and cheek; TnnT1 gene was highly expressed in slow muscle, the TnnT2a gene was highly expressed in cardiac muscle and TnnT3a gene was highly expressed in fast muscle and cheek.The expressions of TnnC1a, TnnC1b, TnnI1b, TnnI1c, TnnI1al and TnnT1 genes were significantly down-regulated with development time increasing(P<0.05), but the expression of TnnC2, TnnI2 and TnnT3a genes still maintained at a relatively high level at 30-60 dph. 【Conclusion】According to the joint analysis of S. chuatsi transcriptome data and genome data, a total of 11 troponin genes of S. chuatsi are identified, among which TnnC2, TnnI2 and TnnT3a genes can be used as important molecular marker genes for the growth and development of fast skeletal muscle of S. chuatsi.