摘要
微卫星是近几年来应用较多的一种分子标记 ,可有效地进行基因鉴定与系谱分析 ,并可估算群体间的遗传距离。通过选用 5个微卫星标记 ,检测了山东省 5个地方鸡种 :日照麻鸡、寿光鸡、莱芜黑鸡、济宁百日鸡、鲁西斗鸡以及一个外来鸡种———安卡黄鸡和一个外省地方鸡种———广西黄鸡共 7个鸡种的遗传多样性。根据测试结果计算了每个等位基因的频率 ,以基因频率为基础分析了品种内的遗传变异和品种间的DA 遗传距离 ,并讨论了微卫星多态性在应用于群体遗传变异及亲缘关系等方面的意义。结果表明 :共检测到 4 0个等位基因 ,其中等位基因数最多的位点为ADL0 136 (10个 ) ;等位基因数最低的位点为ADL0 14 6 (5个 ) ;而且每个位点的等位基因分布并不均匀 ,都有一种或几种优势基因存在。在 7个品种中 ,杂合度最低的为寿光鸡 ,杂合度值为 0 332 7,因为此鸡种多年来一直由寿光市慈伦种鸡场进行纯繁保种 ,未与其他鸡种杂交 ,因此杂合度最小 ;其他鸡种杂合度也都低于 0 4 ,据分析可能是由于日照麻鸡、济宁百日鸡群体较小 ;莱芜黑鸡是正在选育的一个品种 ,个体间遗传关系也不远 ;安卡黄鸡和广西黄鸡自从引入嘉明公司后 ,群体近交现象普遍 ,因此各鸡种杂合度都偏低。由此可见 ,通过对杂合度的计算 ,微卫星可以较好地?
Microsatellite marker is one of the frequently used molecular markers. It has been used in the genotype identification,pedigree analysis and estimation of genetic distance.In this paper,five microsatellite markers with high polymorphisms were selected to detect the genetic diversity of seven chicken breeds.The alleles frequencies,polymorphism information content ( PIC ) and average heterozygosity within each population,and D A genetic distance among breeds were analyzed.The application of microsatellite polymorphisms to the detection of genetic variability and relationship among populations was discussed.Altogether,forty alleles were found in this experiment,and among them the most alleles (10) were detected by ADL0136 and the least (5) were detected by ADL0146 .The distribution of alleles was not balanced,each locus having one or more dominant alleles.The average heterozygosity in the Shouguang chicken was the lowest (0 3327),and that in other breeds was also less than 0 4.It can be seen then that microsatellite polymorphisms can be used to reveal the variability within population through calculation of average heterozygosity.The PIC values ranged from 0 6169 (Shouguang chicken) to 0 7027 (Laiwu Black chicken).UPGMA tree was completed through analysis of D A genetic distance.In the tree,the Rizhao Pockmarked and the Jining Hundred chicken were first grouped together with a bootstrap value of 92%,before they were grouped with the Laiwu Black and the Shouguang chickens.The Anoka Yellow and the Guangxi Yellow chicken were grouped together with a bootstrap value of 80%,but the Luxi Fighting chicken had its own branch.In summary,the UPGMA tree well reflected the evolutionary and breeding history of the seven breeds.
基金
山东省农业良种产业化开发畜牧项目~~
关键词
微卫星
地方鸡
遗传多样性
microsatellite
indigenous chicken breeds
genetic diversity
