Correlation Studies On Three Candidate Genes Affecting EGG Production In Lian Chen White Duck

Lian Chen White Duck is a rare white breed in our country and even in the world, which is considered a variety of the China Spotted Duck, and belong to egg-type and medical type. Deep study on Molecular Mechanism of reproduction performance in LianChen White Duck has great significance on new breed development and reproductive performance improvement. In this study, complete coding region(CDS) of NPY and VTPR gene from duck were cloned and the nucleic acid and protein sequence were analyzed. Study mRNA expression of NPY, VIPR and PRL gene in the hypothalamus-pituitary-ovarian gonadal axis. Detect the gene of NPY、VIPR and PRL by SNP, and analyze the association of the different genotypes and egg number. Full conclusion is as follow:Cloning and sequence analysis of NPY and VIPR gene:the cDNA sequence of NPY and VIPR gene were obtained by PCR amplification, cloning and sequencing. They contain the complete coding region, and the CDS length were294bp and1338bp. NPY gene encoding98NPY protein precursor of amino acid residues, which are classified as unstable proteins. Speculate that the protein is an acidic protein, with strong hydrophilic. VIPR gene contains446protein precursor of amino acid residues, is divided into an unstable protein. Speculate that the protein is an alkaline protein, with strong hydrophobic.Real time PCR analysis the mRNA expression level of NPY, VIPR and PRL gene in the hypothalamus-pituitary-ovarian gonadal axis:The amount of NPY gene expression in the hypothalamic was significantly higher than the pituitary gland and ovaries (P<0.01) in60days, the amount of NPY gene expression in the pituitary was significantly higher than the vertical ovarian (P<0.05), the amount of NPY gene expression in hypothalamic was significantly higher than the pituitary (P<0.01) in300days, the amount of NPY gene expression in the pituitary was significantly higher than the ovary (P<0.01); the amount of NPY gene expression in the pituitary and hypothalamus was significantly higher than the ovary(P<0.01) in500days. The amount of VIPR gene expression in the pituitary was significantly higher than the hypothalamus (P<0.01), and the amount of VIPR gene expression in the hypothalamusin was significantly higher than the ovary (P<0.01) in60and300days; The amount of VIPR gene expression in the pituitary was significantly higher than the hypothalamus and the ovary (P<0.01) in500days, and the difference was not abvious between the hypothalamus and the ovary expression. The amount of PRL gene expression in the pituitary was significantly higher than the ovary (P<0.01),and the amount of PRL gene expression in ovarian was significantly higher than the pituitary (P<0.01) in60days; The amount of PRL gene expression in the pituitary was significantly higher than the hypothalamus (P<0.01),and the amount of PRL gene expression in the hypothalamic was significantly higher than the ovary (P<0.05) in300days;The amount of PRL gene expression in the pituitary was significantly higher than the hypothalamus (P<0.01), and the amount of PRL gene expression in the hypothalamic was significantly higher in the ovary (P<0.01) in500days.Associated analysis between NPY, VIPR and PRL gene polymorphism and the egg number:No nutated sites in1st and2nd exon of NPY gene. The mutation in the3rd exon of VIPR gene and the egg production in500days of Lian Chen White Duck were significantly associated (P<0.05); The mutation in the12th exon of VIPR gene and the egg production in200and400days of Lian Chen White Duck were significantly associated with presence(P<0.05), but these two mutations do not cause amino acid mutations, which are nonsense mutations. The mutation of PRL gene5’untranslated region and the egg production in400and500days of Lian Chen White Duck were significantly associated (P<0.05); The mutation in the1st intron of PRL gene the egg production in300days (PO.05),400d and500days (P<0.01) of Lian Chen White Duck were significantly associated. The mutation in the3rd exon of PRL gene and the egg production in400and500days of Lian Chen White Duck were significantly associated with presence(P<0.05),which form a missense mutation, resulting in the90th amino acid from threonine (Thr) into alanine (Ala).