Analysis Of Polymorphism With Egg-laying Performance And Expression On ESR And NCOA1Gene In Shaobo Hen (S2Line)

In this study, Shaobo hens were taken as materials to study the association between egg-laying performance with ESR and NCOA1genes.1. Single nucleotide polymorphism (SNPS) were detected by PCR-SSCP,1SNP with insert mutation include4nucleotides was found at5’flanking regain of ESR gene, while two SNPS was found at exon10and intron15of NCOA1gene.Analysis of the relationship between polymorphism of ESR gene and egg-laying performance shows that chickens with genotype of EF and EF are the predominant population, which had increased egg production to300days of age(P<0.01) than those with genotype of FF. Analysis of the relationship between polymorphism of NCOA1gene and egg-laying performance indicate that SNP site located in exon10has significantly increased total egg production to300days of age(P<0.Ol) and advanced age at first egg in hens(P<0.05), while SNP site located in intron15significantly advanced age at first egg(AFE)(P<0.05). There is no difference in weight at first egg (WFE) were detected among different genotypes. We conclude that AA and CC genotype are the predominant genotypes in this maternal line of Shaobo hens. Analysis of nine different genotype combinations with the egg laying performance show that AAEE, AAEF and ABEF genotypes are the predominant combinations. They had increased egg production to300days of age, advanced age at first egg and lighter weight at first egg among different genotype combinations.In conclusion, the ER and NCOA1gene can be used as a molecular marker for egg-laying performance in hens.2. Real-time PCR(Q-PCR) were used for identification of the relative expression levels and expression patterns of ESR and NCOA1gene changes in hypothalamus, pituitary and ovary of Shaobo hens.The results indicated that the ESR gene expression level in hypothalamus tissues was higher than that in other tissues after the10th week. The expressions of ESR gene increased in both3tissues from10th week to the28th week, then the rising trend stopped after postnatal developmental stages in ovary tissues, but were still on the rise in other tissues. While, the NCOAl gene expression level in pituitary tissues was higher than that in other tissues. mRNA expression regulation of NCOA1gene was similar to the growth with undulatory property, and there was little expression before the16th weeks.NCOA1gene expression rapidly increased along with sex maturation, the highest expression was found at28weeks then decreased.ESR and NCOA1genes may play an important role in reproductive process. The results suggested that the mRNA levels of ESR and NCOA1gene in gonad tissues was varied in different developmental stages, which provide some data for further study on the ESR and NCOA1genes for elucidating the molecular mechanism of reproduction traits.