Studies On Duck Reproduction Traits Of Heterosis And Its Relationship With Related Gene Expression

In this experiment, Gaoyou (GG) and Jingding duck (JJ), were hybridized directly and reciprocally to produce F1hybrids, Gaoyou×Jingding (GJ) and Jingding×Gaoyou (JG) hybrid groups were selected to investigate relationship between differential expression of gene and heterosis. Four groups of reproduction traits and egg quality were observed, comparison and analysis of them and calculate heterosis. A pair of primers was designed according to the conserved regions of anas platyrhynchos, cairna moschata and gallus gallus in Genbank, and the majority sequences of FSHR, ERβ and GHR three genes were cloned.Real-time PCR was carried out to compare expression levels of three genes in hypothalamus-pituitary-ovary axis of Gaoyou, Jinding duck and crossed populations during early laying period, laying fastigium period and later laying period, and analyzed relationship between differential expression of genes and heterosis in hybrid species. The main results are as follows:In the first experiment, the reproduction traits and egg quality of GG,JJ,GJ and JG were compared. It was found that GJ and JG had distinct heterosis in laying age, reproduction of42-week-old and72-week-old, eggshell intensity and egg white hight. It provides basic for developing this study.In the second experiment, cloning and sequencing of target genes. The results showed that the majority sequences of domestic duck FSHR, ERβ and GHR gene were obtained.In the third experiment, study on the relationship between differential expression of gene and heterosis of reproduction traits. It was found: 1. Real-time PCR analysis showed that the expression levels of FSHR gene in pituitary, there were extremely significant differences (P<0.01) between parents and their hybrids during laying fastigium period. At the same time, the expression levels of FSHR gene in pituitary of two hybrid species were positively significant correlated to their heterosis percentages of laying age (P<0.05), negatively significant correlated to their heterosis percentages of reproduction of42-week-old (P<0.05) during laying fastigium period. These results indicated that the heterosis of laying age, reproduction of42-week-old were related to the differential expression of FSHR in pituitary during laying fastigium period.2. Real-time PCR analysis showed that the expression levels of ERβ gene in pituitary and ovary, there were differences (P<0.01,P<0.05) between parents and their hybrid species during laying fastigium period. At the same time, the expression levels of ERβ gene in pituitary of two hybrids were positively significant correlated to their heterosis percentages of laying age (P<0.05), negatively significant correlated to their heterosis percentages of reproduction of42-week-old (P<0.05), and in ovary were positive extremely significant correlation to their heterosis percentages of laying age (P<0.01), negatively significant correlated to their heterosis percentages of reproduction of42-week-old (P<0.05) during laying fastigium period. These results indicated that the heterosis of laying age, reproduction of42-week-old were related to the differential expression of ERβ in pituitary and ovary during laying fastigium period.3. Real-time PCR analysis showed that the expression levels of GHR gene in hypothalamus-pituitary-ovary, there were not significant differences (P<0.05) between parents and their hybrid species during laying period. At the same time, the expression levels of GHR gene in different tissues of two hybrids were lower correlated to their heterosis percentages of reproduction traits, except the expression levels of GHR gene in pituitary rather high correlated to their heterosis percentages of reproduction of72-week-old during laying fastigium period. These results indicated that the heterosis of reproduction traits were no significant related to the differential expression of GHR during laying period.