Cloning Of Duck Myod1 And Myf5 Genes Cds Sequences And Research About Their Differential Developmental Expression In Duck Muscle Tissues

The MRFs gene family includes four members as following MyoDl, MyoG (Myogenin), Myf5 and MRF4 (Myf6, herculian). They play key roles in a cascade of stages during animal myogenesis such as in the myoblast determination and proliferation, myofibers forming and in the myofibers maturation and functions consummation. Among of these four gene family members, the MyoDl is related to the early myoblast determination in animal trunk muscle, while Myf5 to the myoblast determination in the limb muscle. In this research, the duck MyoDl and Myf5 genes coding region sequences (CDS) were cloned, and the relative developmental mRNA expression levels of these two genes were detected in the muscle tissues after duck embryo formed using the quantitative relative PCR method. These researches are the fundamental works for investigating the roles of MyoDl and Myf5 in skeletal muscle, smooth muscle and cardiac muscle, and can also raise the knowledge about their roles in muscle development. The results are as following:1. The duck MyoDl and Myf5 gene CDS sequences are cloned,894bp and 768bp, respectively, encoding for 297AA and 255 AA (Genbak accession number:FJ374143 and FJ938240, respectively). It has a high homology with other organism sequences both at the nucleotide level and at the amino acid level.2. Both of the duck MyoDl and Myf5 contained a bHLH domain region. The regions are homologous with that of chicken, and the homology is 100%. Only 2 and 1 variations can be found for the duck MyoDl and Myf5 comparing with athe of human, while 2 and 6 variations can be found comparing with that of zebrafish, respectively.3. Only 4 variations can be found comparing between the duck MyoDl and Myf5 bHLH regions. The distribution of alpha helix, random coils and extended strands at the carboxyl-termini and amino-termini for duck MyoDl and Myf5 make some differences. Both of the duck MyoDl and Myf5 gene CDS sequences have the phosphorylated sites of Ser, Thr and Tyr, and the phosphorylated sites are mainly distributed in the carboxyl-termini and amino-termini of the amino acid sequences.4. The MyoDl and Myf5 genes have a expression in the duck breast muscle and leg muscle during embryo developmental stages of 10d,14d,18d,22d,27d, and postnatal 7d. In the duck breast muscle, the mRNA expression of MyoDl reached the peach at embryo stage 18d, while the mRNA expression of Myf5 at embryo stage 27d. In the leg muscle of duck, the mRNA expression of MyoDl and Myf5 reach the peach at the same embryo stage, which is at 14d. It has a different expression patterns for the duck MyoDl and Myf5 genes after the peach expression stage, which the expression tendency of MyoDl decreased immediately and sustained to the duck postnatal 7d stage, while the expression of Myf5 decreased slowly.5. The expression of MyoDl and Myf5 are detected in duck heart tissues and intestine muscles using a sensitivity quantitative RT-PCR method. But it hasn't a noticeable pattern for them and the effect of thme in heart tissues and intestine muscles are not clearly.6. There is a different expression patterns for MyoDl and Myf5 between duck breast muscle and leg muscle, because they have a different embryo origination, and also because these two muscles are constituted by different myofiber types. The duck leg muscle develops earlier than the duck breast muscle after the embryo formed.