Cloning And Expression Of Tianfu Goat TNNI1and TNNI3Gene And Their Relationship With Muscle Tissue Traits

Troponins (TNs), belong to a member of multigene family of Ca2+binding proteins, plays a critical role in skeletal muscle contraction and improving meat quality traits of livestock and poultry. The troponins gene has been identified in many mammals, but very little known about goat. Here, we cloned TNNI1and TNNI3gene in Tianfu goat for the first time and analyzed its tissue expression. After submitted to NCBI two Genbank ID were obtained (TNNI1:JN848968;TNNI3:JN848969). Troponin is composed of three components; troponins C, I and T. TNNI gene affects muscle fiber histological character, muscle fiber diameter and type a direct impact on the fleshy tender degrees, and muscle fiber type and according to the contraction of different types and classification. Researches have showed that troponin system was associated with meat tenderness, meanwhile TNNI1and TNNI3can be regarded as important candidate genes for meat quality character.Results indicated that TNNI1gene complete open reading frame (ORF) for564bp, code187amino acids. Amino acid sequence exists a conservative structure domain; Protein secondary structure with random crimp and alpha screw is given priority to, there are multiple phosphorylation site. By real time quantitative technique, the tissue expression of TNNI3in Tianfu meat goat was analysed. The results show that TNNI1gene in choice of tianfu goat12organization, abdominal muscle express quantity highest, leg muscle second, and other organizations difference was significant (P<0.01); In the abdominal muscle tissue TNNI1gene expression quantity along with the growth of the age and reduce.Bioniformation analysis showed that goat TNNI3gene’s complete open reading frame (ORF) of639bp and encoding212amino acids, the analysis of amino acid sequence revealed that TNNI3contained three conserved domains, the protein secondary structures mainly were random coil and helical regions, contained certain conserved phosphorylation sites. By real time quantitative technique, the tissue expression of TNNI3in Tianfu meat goat was analysed, the results showed that the expression of TNNI3in heart was the highest in all12tissues. It is significantly higher than other internal organ tissues; the expression of TNNI3decreased with the rise of the age.The muscle traits analysis revealed that the muscle fiber diameter of tianfu goat was significantily lower than the local black goat (P<0.05), it means better meet quality and more tender, and the muscle fiber diameter of ewe of tianfu goat was significantly lower than the Rams(P<0.05), it means the ewe has better meet quality and more tender. In different ages, the youngest ones had lowest muscle fiber diameter with the best meet quality and tender. The expression of TNNI1gene in abdominal at different ages with muscle fiber diameter and cross-sectional area showed a significant positive correlation (P<0.05), and a significant negative correlation with muscle fiber diameter(P<0.05); while The expression of TNNI3gene in cardiac muscle at different ages and muscle fiber diameter was a significant negative correlation (P<0.05), a not significant negative correlation with a single muscle fiber cross-section area, and a extremely significant positive correlation with muscle fiber density (P<0.01).