不同疫源地鼠疫宿主动物的DNA条形码比较研究

A comparative study of DNA barcode of plague host animals between different foci

目的评估应用DNA条形码技术鉴定不同地理区域物种的可行性。方法选取内蒙古自治区3个鼠疫自然疫源地4种鼠疫宿主动物的DNA条形码进行比较，分析GC碱基含量和密码子偏好性、计算遗传距离，采用邻接法（NJ）构建分析系统发育树。结果不同疫源地的五趾跳鼠GC碱基含量比较差异有统计学意义（F=5．34，P〈0．05），长爪沙鼠疫源地五趾跳鼠的GC碱基含量变异较大，与其他疫源地五趾跳鼠比较差异均有统计学意义（P均〈0．05）。不同疫源地间同一鼠种很少存在种内密码子变异位点；各鼠种种内平均遗传距离均〈1％，种间遗传距离均〉18％。结论各鼠种DNA条形码具有特异性，不存在物种间共享，不因地理位置变化而改变。利用DNA条形码可以达到鼠疫宿主动物分子鉴定的目的．

Objective To illustrate more accurately the feasibility of DNA barcode technology in species identification in different geographical areas. Methods Four plague host animals were selected from three plague natural foci in Inner Mongolia for DNA barcode comparison, GC base content, codon preference and genetic distance calculation, and a phylogenetic tree was constructed. Results Compared between different foci of A llactaga sibirica, the difference of base content was statistically significant （F = 5.34, P 〈 0.05）; the variation of Meriones unguiculatus focus Allactaga sibirica base content was larger, and compared with other foci Allactaga sibirica, the difference was statistically significant （all P 〈 0.05）. Different foci between one species rarely exist in codon sites. The genetic distance of intraspecific was less than 1%, and the genetic distance of interspecific was more than 18%. Conclusions DNA barcode of each species is specific, with no interspecific species sharing, and does not change with geographical position. Molecular identification of plague host animal is effective by DNA barcode.