Effects Of Dietary Energy Levels And NPY Gene On Traits Of Reproduction Of WenChang Chicken

In the reseach, Wenchang chicken were randomly divided into 3 groups: low energy(Groupâ… ), control (Groupâ…¡) and high energy (Groupâ…¢). Wenchang chickens in this research were detected genetic variation of the transcription start site of the NPY gene in the 3 groups by means of using PCR-RFLP, analyzed the association of NPY gene polymorphism with raits at first egg and egg production of Wenchang chicken in different energy diets, Furthermore this study investigated the expression characterization of NPY gene in hypothalamus and ovary by real-time quantitative PCR in different energy diets. The main results are as follows:1 . Genetic variation had been found at the transcription start site of NPY gene. There was a 4bp deletion at Draâ… site which has three genotype. The frequencies of AA, AB and BB genotype were 0.1305,0.5594,0.3101,respectively, and the frequencies of A and B alleles were 0.4103 and 0.5897 respectively. Wenchang chicken was not in Hardy-Weinberg equilibrium.2. The body weight at first egg of AA genotypes in Groupâ…¢were significantly bigger than that in Groupâ… (p<0.01), the interaction between energy and NPY genotypes had significant effects at body weight at first egg (p<0.01). Age at first egg of BB genotypes in Groupâ…¢were 6.41d significantly smaller than that in Groupâ… (p <0.01). There were no significant difference on traits of at early laying performance in AB genotypes (p>0.05). The effects of energy, NPY genotypes and interaction on traits of at early laying performance were: interaction>ME>NPY genotypes. The interaction between energy and NPY genotypes had significant effects at egg production (300 d) (p<0.05). There was no significant difference on egg weight (300d) between energy level and the 3 NPY genotypes (p>0.05).3. Real-time quantitative PCR analysis indicated that NPY gene expressed and ovary, the changes of NPYmRNA in ovarian was same as the hypothalamus. NPYmRNA content in the hypothalamus was reduced when the energy level increased at 15, 20, 25 weeks(p>0.05). The trendency of NPYmRNA concentration in hypothalamus was the same as the trendency of egg at first day in difference energy levels.