Cloning Of MYOZ2, MYOZ3 Gene In Ovine And Tissues With Time Expression In Liangshan Semi-fine Wool Sheep

MYOZ2 and MYOZ3 belong to MYOZS family members which are a muscle-specific proteins, playing important roles mainly in skeletal muscle and cardiac. Their products can activate a variety of muscle-related gene expression occurred and also play important roles in the process of differentiation and development in muscle fibers or cardial diseases.In order to study the structure and expression patterns in different tissues and time after birth of the MYOZ2 and MYOZ3 gene in Liang-shan semi-fine wool sheep. The complete coding region of gene was amplified according to the sequence of conservative parts in Bos taurus,Homo sapiens and Mus musculus by GenBank. We use QRT-PCR method to analyze the relative expression levels of MYOZ2 and MYOZ3 gene in different tissues at different time by the primer designed on the basis of the cloning sequence. We get the complete CDS region of the MYOZ2 and the MYOZ3 sequences. The MYOZ2 contains 951bp and encodes 264 amino acids. The amino acids sequence of Liang-shan semi-fine wool sheep homology with Homo sapiens,Bos taurus and Mus musculus is 90.27%,97.99%,87.58% respectively. The MYOZ3 contains 838bp and encodes 244 amino acids. The amino acids sequence of Liang-shan semi-fine wool sheep homology with human,cattle and Mus musculus is 79.30%,94.27%,72.40% respectively. The results tell us The MYOZ2 and the MYOZ3 gene are the more conservative evolution of species. The proteins of the MYOZ2 and the MYOZ3 contain three structural domains:two a-helix regions and a Gly-rich region in the middle. The N-terminal and C-terminal of the two gene were very conserved after homology blast and the middle region mutated dramatically. The signal peptide and the transmembrane of two gene are not found. Ser residus are the major residus in the phosphorylation sites. The secondary structure of protein is dominate by Random coil, and also contains Helix and Sheet. Three hydrophobicity regions of the MYOZ2 contain 7,7,4 amino acids respectively. Three hydrophobicity regions of the MYOZ3 contain 9,6,lamino acids respectively.We researched the expression of the MYOZ2 and the MYOZ3 genes in different tisssues with different growth period by QRT-PCR technique. We selected six periods randomly which are 15d,60d,105d,160d,195d and 240d and each period contains three Liang-shan semi-fine wool sheeps. collecting back muscle,liver,heart,skin and tissue to research. The results showed that the MYOZ2 and the MYOZ3 gene are high expression in back muscle and heart, but very low in brain,liver and skin. The maximum expression in different time isn't the same tissue, the MYOZ2 and the MYOZ3 genes expression level are significantly different betweenl5d and 60d, aslo with other tissues(P<0.01), but the expression level of two genes are not significantly different between brain,liver and skin(P>0.05). Through the research we can guess the both of genes are one of candidate gene by playing an important role in growth development and heart disease after birth. The both of genes expression pattern was tissue-specific,the expression tissues of the MYOZ2 gene are back muscle and heart, but back muscle of the MYOZ3.