mtDNA COI和ND5基因用于鉴别常见嗜尸性蝇类

目的对蝇类mtDNA 523bp COI和347bp ND5基因片段进行序列分析,评价其在以嗜尸性蝇类种属鉴定中应用的可行性。方法从广州(广东省)、湛江(广东省)、韶关(广东省)、沈丘(河南省)及蜂蛹寨(四川省)采集7种嗜尸性蝇类标本,进行形态学种属鉴定,取其腹部肌肉提取DNA,利用基因特异性引物对线粒体COI、ND5基因进行PCR扩增,产物经纯化后进行测序,MEGA 3.0软件对DNA序列进行碱基组成、进化分歧率和系统发育分析。结果进化分歧率ND5基因种内小于1.83%,种间大于2.62%;种间与种内进化分歧率范围间没有交叉;COI基因种间在0.48%～14.8%之间,种内在0.24%～8.3%之间,种内进化分歧范围与种间进化分歧范围存在交叉。结论 ND5基因片段可在种水平有效鉴别常见嗜尸性蝇类,也可鉴别近缘种。而单独运用COI基因不能有效进行种属鉴定。

Application of mtDNA COI and ND5 genes in the identification of common necrophagous flies

Objective In order to estimate their feasibility in the identification of necrophagous flies,the mitochondrial DNA(mtDNA) sequences of 523bp of the COI gene and 347bp of the ND5 gene were analyzed.Methods By use of entomological morphology we collected seven types of necrophagous flies from Guangzhou,Zhanjiang,Shaoguan,Guangdong province,Shenqiu,Henan province and Fengyongzhai,Sichuan province.After the DNA was extracted from the abdominal muscles of the flies,mtDNA COI and ND5 genes were amplified using sequence specific primers by PCR,and then the PCR products were purified and sequenced.The DNA sequence,genetic distance and systemic development were analyzed with MEGA3.0 software.Results The evolutionary difference rate of ND5 gene is less than 1.83% intraspeciesly,and is more than 2.62% interspeciesly,which indicates no cross of the two ranges,whereas the evolutionary difference rate of COI gene is between 0.48% and 14.8% intraspeciesly,and is between 0.24% and 8.3% interspeciesly,which shows that the ranges cross.Conclusion ND5 gene can effectively identify the species of necrophagous flies as well as some allied kinds,but COI gene alone can not identify the species.