基于线粒体cox1和Cyt b基因对四川地区多头带绦虫的种群遗传多样性研究

Population Genetic Diversity of Taenia multiceps Isolated from Sichuan Based on Mitochondrial cox1 and Cyt b Gene

为研究四川地区多头带绦虫的种群遗传多样性和系统发生关系,用线粒体cox1基因和Cyt b基因全序列分析了20株四川山羊源多头蚴(11株寄生于脑,9株寄生于肌间)的遗传变异,并构建了系统发育树。结果显示:20株多头蚴cox1和Cyt b基因全序列长度分别为1 623和1 068bp,分别有59个和9个变异位点,其碱基变异率分别为0.1%~2.5%和0.1%~0.7%;分别检测到17个和6个单倍型,总的单倍型多样性分别为0.968±0.033和0.737±0.068,核苷酸多样性分别为0.005 98±0.001 33和0.003 06±0.000 79,平均遗传距离分别为0.006和0.003。构建的系统进化树均显示来源于脑部和肌间的20株四川山羊源多头蚴与多头带绦虫同在一个支系,均为多头带绦虫,且多头带绦虫四川分离株与伊朗、土耳其分离株亲缘关系较近,而与中国甘肃、中国广州、意大利分离株亲缘关系较远。研究结果表明线粒体cox1和Cyt b基因均可作为检测多头带绦虫种群遗传多样性的有效分子标记,且Cyt b基因的多样性水平低于cox1基因。

To study the population genetic diversity of T.multicepsisolated from Sichuan and the phylogentic relationships with other taeniaspecies,the complete sequences of mitochondrial Cytochrome c oxidase subunit 1(cox1)and Cytochrome b(Cyt b)genes of 20 Coenurus collected from goats(11from brain,and 9from intramuscular)in Sichuan were analyzed and phylogentic trees were reconstructed.The results showed that the complete lengths of mitochondrial genes sequenced in this study were 1 623bp for cox1gene and 1 068bp for Cyt b gene.Variable sites were 59and 9,respectively.The sequence divergence between the cox1sequences of Coenurus isolated from Sichuan ranged from 0.1%to 2.5%,while differences in Cyt b sequences ranged from 0.1% to 0.7%.Seventeen haplotypes and 6haplotypes were detected in cox1and Cyt b,with the global haplotype diversity being 0.968±0.033(cox1)and 0.737 ± 0.068(Cyt b),the nucleotide diversities were 0.005 98±0.001 33for cox1and 0.003 06±0.000 79for Cyt b,and the averagegenetic distances were 0.006for cox1and 0.003for Cytb,respectively.The phylogenetic trees inferred from both cox1and Cyt b showed that all 20 Coenurusisolated from Sichuan were the species T.multiceps.A closer relationship was found between Sichuan isolates and Iran and Turkey isolates,and it was closer than that between Sichuan and Gansu,Guangzhou and Italy isolates.The results indicated that cox1gene and Cyt b gene were suitable markers for detecting genetic diversity of T.multiceps,and the diversity of T.multiceps based on Cyt b gene was lower than cox1gene.