Cloning, Expression Pattern And Association With Carcass And Adipose Traits Of MC4R And ADD1 Genes In Meat Duck

In this study, we collected the brain samples of Peking duck to clone MC4R and ADD1 genes by RT-PCR, further predict their structure and function by bioinformatics, analyze their expression in different tissues of 8 week old Peking duck by real-time fluorescence quantitative PCR, detect the genetics diversity of different exons of ADD1 gene using PCR-SSCP and sequencing assay technologies, and analyze the association between the polymorphisms and growth and adipose traits in Peking duck Z2, Z4, hybrid line and Cherry Valley duck population using general linear model with SPSS 13.0. The main results were showed as following:1. Cloning and bioinformatics analysis of MC4R and ADD1 gene in Peking duckThe MC4R and ADD1 gene were cloned by RT-PCR. They all contained complete CDS sequences, the length were 996bp and 2293bp seperately. We submitted them to GenBank and obtained the accession number of these sequences FJ842531and FJ906770. Aligned the MC4R and ADD1 nucleotides of duck with the sequences of human and chicken, the homology of them were all above 75%. The structure and function of MC4R and ADD1 gene were predicted using bioinformatics. A G-protein coupled receptors family 1 profile and a G-protein coupled receptors family 1 signature was contained in MC4R protein, and there was no complex special structure in ADD1.2. Expression pattern of MC4R and ADD1 gene in Peking duckExpression pattern of MC4R and ADD1 gene in leg muscle, abdominal fat, liver, heart, kidney, spleen, brain and lung were studied by real-time fluorescent quantitative PCR. The results showed: MC4R gene was expressed in various tissues with different levels. The highest expression level was detected in brain, less in spleen, heart, leg muscle, abdominal fat and kidney, and lowest in liver and lung. ADD1 gene was expressed in various tissues. And the highest expression level was detected in brain, less in leg muscle, heart, kidney and lung, and the lowest in abdominal fat, liver and spleen.3. Effects of polymorphisms of ADD1 gene on carcass and adipose traits of ducks Association analysis revealed that the homozygous (AA) birds had significant higher SFW than homozygous (BB) in Z2. The homozygous (AA) birds had significant higher carcass weight than the homozygous (AB) in Z4. The homozygous (AA) birds had significant lower IMF than homozygous (BB) in Cherry Valley duck. The homozygous (AA) birds had significant higher leg muscular weight than homozygous (BB) and the homozygous (AA) birds had lower percentage of AFW than heterozygote (AB) and homozygous (BB) in Hybrid Peking duck.The study, cloning, expression pattern and association with carcass and adipose traits of MC4R and ADD1 genes in meat duck, provides a theoretical basis for further study of the biological function of MC4R and ADD1 gene. It also lays a theoretical foundation for understanding the mechanism in the fat deposition.