MEF2D Gene Coding Region Clone And Association Analysis Between Its Microsatellite Polymorphism And Slaughter Performance Of Duck

Myocyte enhancer factor 2 (MEF2) is belonging to a large family of transcription factor MADS-box. MEF2 family gene is a single gene In Drosophila and C. elegans and contains four family members in vertebrates including MEF2A, MEF2B, MEF2C, MEF2D four genes. MEF2 gene family are widely expressed in cardiac cells, skeletal muscle cells and nerve cells and have a function to activate various gene expression in terms to muscle tissue differentiation, development and regeneration. In addition, MEF2 binding sites have been found in almost all muscle regulatory factors. As a member of MEF2 family, it is demonstrated a significant physiological role of MEF2 on cardiac, skeletal and nerve cell formation and growth., Thus, obtaining the MEF2D coding region sequence is important to elucidate its mechanism underling muscle tissue differentiation, development. Meanwhile,in previous studies, a (CAG)n repeating microsatellite sequence was found in 9th Exon region of MEF2D gene. This study planed using molecular cloning techniques to get the whole duck MEF2D gene coding region sequence, then further identificated Whether CAG repeat Exists polymorphism, And analysised the possible effects between the microsatellite loci’s polymorphisms and Beijing duck and Jiancang duck carcass traits.The main findings are as follows:(1).We have cloned the whole coding region of the MEF2D gene encoding 525 amino acid residues, with a full-length of 1578bp, formula of C2471H3954N732O809S13, molecular weight of 57277.7Da. Duck MEF2D gene contained the MADS-box region and have some MEF2 domain characteristics, in which MADS-box region located from 3th amino acids to 57th amino acids.(2). In different species, both of the MADS-box and MEF2 domains have high homology, of which MADS-box homology to 100%.(3).Through the analysis of duck MEF2D protein structure, we found that the protein belongs to the intracellular protein,60.9% of which located in the nucleus. Secondary structure analysis revealed that random coil accounts for 65.9%, a helix occupied 20.95%, β fold represented 11.24%.(4).Sequence alignment discovered that the obtained MEF2D gene had a microsatellite loci on its exon region, which was took(CAG) as a repeating unit.(5).Polymorphism detected on CAG repeat,which was contained by MEF2D, found that microsatellite loci on exon region of MEF2D had a significant correlation with breast muscle weight of Jianchang duck, Which heterozygous brest muscle weight was significantly higher than homozygotes’.