京海黄鸡LYZ基因外显子的遗传多态性及其与体重的关联分析

Polymorphisms in the Exon Region of Jinghai Yellow Chicken LYZ Gene Associated with Body Weight

试验旨在研究鸡溶菌酶基因(LYZ)对鸡体重的影响。以200只京海黄鸡为研究群体,采用PCR-SSCP和DNA测序的方法检测LYZ基因单核苷酸多态性,并将所发现的SNPs与体重进行关联分析。结果发现,共3个突变位点,且均为沉默突变,未引起氨基酸序列的改变;经χ2适合性检验,除1411位点外,其他2个突变位点均显著偏离Hardy-Weinberg平衡;111位点AA基因型个体12和16周龄体重显著高于GG基因型个体(P<0.05),1411位点AA和GA基因型个体各周龄体重均高于GG基因型个体,且4周龄体重差异达到了显著水平(P<0.05),1426位点各基因型对体重没有显著影响(P>0.05)。单倍型分析结果显示,除4周龄外,ANC个体各周龄体重均较大,GAC个体4周龄体重较大,这与上述各位点基因型对体重影响的分析结果相一致,暗示在选种、育种过程中,可将鸡LYZ基因作为京海黄鸡体重候选基因应用于遗传标记辅助选择。

To help find the physiological functions of the chicken lysozyme gene,the current study was designed to investigate the association of chicken lysozyme gene polymorphism with chicken body weight.200 female Jinghai Yellow chickens were involved in this experiment.To determine gene mutations,DNA analysis of the lysozyme gene,including single strand confirmation polymorphism（SSCP）,and direct DNA sequencing was performed.Three single nucleotide polymorphisms（SNPs） were indentified,all of them were silence mutations that caused no alteration in amino acid sequence.Chi-square test showed that only genotypes of the 1411 locus were at Hardy-Weinberg disequilibrium.For 111 locus,body weight of the genotype AA chicken at twelve and sixteen-week of age was significantly higher than that of genotype GG chicken（P0.05）.For 1411 locus,body weight of genotype GG chicken at four-week of age was significantly lower than that of genotype AA chicken（P0.05）.In the meanwhile,for 1426 locus,associations between genotypes with body weight were no significant（P0.05）.Statistical analysis of haplotype of the chicken LYZ gene and body weight approved the genotypes.Chicken of haplotype ANC were heavier than other chicken except four-week of age,and chicken of haplotype GAC were heavier at four-week of age than other chicken.Therefore,the lysozyme gene might be a potential marker for use in marker-assisted selection programs in Jinghai yellow chicken breeding.