从线粒体DNA控制区基因探讨红腹锦鸡和白腹锦鸡的分类关系

Taxonomic Relationship between Chrysolophus Pictus and C.amherstiae Based on Mitochondrial DNA D-Loop Gene

用聚合链式反应(PCR)和直接测序的方法测定红腹锦鸡(Chrysolophus pictus)和白腹锦鸡(C.amherstiae)各5个样本线粒体DNA控制区的468 bp的序列,共发现26个变异位点.红腹锦鸡的序列变异率为0.90%,白腹锦鸡的序列变异率是0.17%,两者差异极显著.红腹锦鸡和白腹锦鸡的3种碱基(A,T,C)含量差异显著.根据Kumar双参数法计算两种锦鸡的遗传距离为0.035±0.008,按线粒体DNA控制区的进化速率2%/Myr计算,它们的分歧进化的时间大约是(1.75±0.40)Myr,结果支持它们是两个独立的种.红腹锦鸡和白腹锦鸡可能分别起源于秦岭以南地区和横断山脉.

This study used polymerase chain reaction and direct sequencing method to infer the taxonomic retationship between Golden Pheasant （ Chrysolophus pictus ） and Lady Amherst＇ s Pheasant （ C. amherstiae ）. A total of 468 nucleotides of the mitochondrial DNA control-region gene were sequenced. There are 26 variable positions, with 19 transi- tions, 6 tmnsversions and 1 deletion. The sequence variation was very significantly different between Golden Pheasant and Lady Amherst＇ s Pheasant. What＇ s more, the nucleotide composition of A, T and C were noted different between the two pheasants. Genetic distance between Golden Pheasant and Lady Amherst＇ s Pheasant was 0. 035 ± 0. 008 based on Kimura-2-parameter＇ s method. The divergence time between Golden Pheasant and Lady Amherst＇s Pheasant was （1.75 ± 0.40） Myr using the rate of 2% mtDNA sequence divergence/1Myr. This result suorted that Golden Pheasant and Lady Amherst＇ s Pheasant were two distinct species. The ancestors of Golden Pheasant and Lady Amherst＇ s Pheasant could have evolved allopatrically in the southern of Qinling Mountain and the Hengduan Mountain.