摘要
采用聚合链式反应和直接测序方法测定石鸡和大石鸡线粒体DNA(m tDNA)控制区全序列,分析m tDNA 3个区的序列变异,比较两种石鸡的遗传变异。石鸡m tDNA控制区全序列长1 154 bp,大石鸡是1 157 bp。与大石鸡相比,石鸡m tDNA控制区在第187位,第1 060位和第1 110位缺失。两种石鸡之间,m tDNA控制区I区、II区和III区的序列变异率分别为5.70%,0.64%和3.22%,I区的变异速率最快。石鸡m tDNA控制区的碱基含量是:T32.13%,C27.17%,A26.43%和G14.23%,大石鸡的分别是T32.30%,C26.79%,A26.10%和G14.81%。t-检验分析显示,石鸡和大石鸡m tDNA控制区的4种碱基含量差异都极显著。两种石鸡间的遗传距离是0.038 4。根据分子钟计算,它们的分歧时间大约在190万年前。它们的物种形成主要受青藏高原的隆升和更新世第2次寒冷期的影响。
Mitochondrial DNA control- region （mtDNA D- loop） can be divided into three domains, corresponding to the highly variable peripheral domains Ⅰ and Ⅲ and to the central conserved domain Ⅱ of vertebrates. Polymerase chain reaction and direct sequencing methods were used to analyze the entire mtDNA D -loop in Chukar partridge （Alectoris chukar） and Przevalski partridge （A. magna）. The aims are to infer sequence variation of the three domains of mtDNA D - loop gene and to compare the genetic variation between Chukar partridge and Przevalski partridge. D -loops were 1 154 nucleotides （nt） long in Chukar partridge, 1 157 nt in Przevalski partridge （nt187, 1 060 and 1 110 were deleted in Chukar partridge）. The sequence variation rates of domains Ⅰ, Ⅱ and Ⅲwere separately 5.70% , 0.64% and 3.22% between Chukar partridge and Przevalski partridge, which indicated the variation rates of domains Ⅰ was the fastest. The nucleotide composition of Chukar partridge mtDNA D -loop was： 32.13% T, 27.17% C,26.43% A,14.23% G,and 32.30% T,26.79% C,26.10% A,14.81% G of Przevalski partridge. There were very significant differences in the contents of the four nucleotides between Chukar partridge and Przevalski partridge. Genetic distance was 0. 038 4 between the two partridges. The calibrated rates of molecular evolution suggested that they speciated about 1.90 million years ago, affected by the uplift of Qinghai - Tibet Plateau and the Pleistocene second frigid stage.
出处
《江西农业大学学报》
CAS
CSCD
北大核心
2006年第3期420-424,共5页
Acta Agriculturae Universitatis Jiangxiensis
基金
国家自然科学基金资助项目(30530130)
关键词
线粒体DNA控制区
石鸡
大石鸡
遗传变异
mitochondrial DNA D - loop
Alectoris chukar
Alectoris magna
genetic variation
