关键词: 鸡, NCOA1基因, 产蛋性状, 单核苷酸多态

Abstract: Four native chicken breeds (Qingyuan partridge,Baier chicken,Luyuan chicken,Tibetan chicken) and S₂ line broiler were used to investigate the effect of nuclear receptor coactivator 1 (NCOA1) gene on chicken egg production traits.Single nucleotide polymorphisms (SNPs) were detected by PCR-SSCP.The results showed that T/A substitution was detected at position 10155007 in exon 3,AA,AB and BB genotype were found.And C/T substitution at position 108273423 in exon 12,CC,CD and DD genotype were found.The χ²-test revealed that there was highly significant difference in the frequency of genotype produced by mutation among breeds or line (P<0.01).Allele frequencies of A and C were high in Baier chicken which belongs to the native breed that has dominant egg type traits.Allele frequencies of B and D were high in Qingyuan Partridge,Tibetan and S₂ line.It can be viewed that they have same genetic background which has dominant meat type traits.The least square analysis with age at first egg (AFE),weight at first egg (WFE),continual laying (CL),and the total number of eggs with 300 age (NE) in S₂ line chicken showed the difference between genotypes,and reproductive traits.The CL of genotype AA is 0.59 d more than BB genotype,the WFE is 0.6 g and the NE is 7.76% higher than that of genotype BB,and the difference is significant (P<0.05).The CL of CC genotype is 0.51 d more than DD genotype,the WFE is 1.04 g,and the NE is 9.07% higher than that of genotype DD,and the difference is significant (P<0.05).The haplotype of AACC on AFE,CL and NE was higher than the haplotype genotype BB and DDt.From the results we can tentatively conclude that NCOA1 gene is the major gene to affect the egg production traits or it links with the major gene.

Key words: chicken, NCOA1 gene, egg production traits, SNPs