| Muscovy duck is excellent meat poultry, that is the farmer and the consumer’s favorite, but the factors of long breeding cycle, high cost of feeds, less egg number,reducing the Muscovy Duck profits to the producer. The Muscovy duck production traits are still need to be improved, especially reproductive traits. It is difficult for the traditional breeding methods to make a precise selection of reproductive traits, which requires us to start from the molecular markers. This experiment selects the IGF2, IGFBP2 and DRD2 as the object of study, then we amplified the CDS region of the four genes, and then we tested the expression pattern of each gene in Muscovy duck. in addition, we searched their polymorphic loci, and to explore the correlation analysis between these SNPs and Muscovy Duck reproductive traits.This experiment successfully amplified the full-length CDS of IGFBP2 and DRD2,but for IGF2 gene only amplified part of the CDS region. The mr RNA level of IGF2 gene has significantly expressed with highest level in the kidney and ovary, and with significant expression in the heart, liver, cerebrum, cerebellum, pituitary and abdominal fat; The IGFBP2 gene has significant expressed in the heart; The DRD2 gene has highly significant expressed in ovarian, cerebrum, cerebellum and hypothalamus and pituitary. All these three genes had a high level of expression in ovarian tissues. Therefore, it is assumed that these three genes may have a certain correlation with reproductive traits.50 SNPs were found in IGF2, IGFBP2 and DRD2 genes, and we selected 19 of them for correlation analysis. From the results of the correlation analysis, we showed that A-1864 G and C-1704 G sites of IGF2 gene were significantly associated with 59-week-old egg number(P < 0.05), and there was no significant difference with egg production and300-days-old egg number(P > 0.05), and the allele frequency of 2 sites was consistent with Hardy-Weinberg equilibrium; The 6 SNPs of IGFBP2 gene had no significant correlation with the egg production, 59-week-old egg number and 300-days-old egg number(P > 0.05),but multiple comparison results showed that the different genotypes had certain correlation with reproductive traits, and we found the allele frequencies of 6 SNP in accordance with the Hardy-Weinberg equilibrium; The C+7T, A+3183C, C+3301G And A+3484T and A+3489G sites of DRD2 gene were significantly correlated with 59-week-old egg number(P < 0.05). The T+3423C site was extremely significantly related to 59-week-old egg number(P < 0.01); The C+7T, C+364G and T+3423C sites were significantly correlated with the egg production(P < 0.05), and the T+3423C site was significantly correlated with the 300-day- egg production(P < 0.05). In addition to the C+7T and C+364G sites, the other sites were consistent with Hardy-Weinberg equilibrium. The test was found several molecular markers in IGF2, IGFBP2 and DRD2 genes, significantly related to reproductive traits, and these molecular markers can be provided as candidate markers for future breeding. |
