云南省大理白族自治州亚洲带绦虫线粒体Cytb基因遗传多样性分析

Genetic diversity of mitochondrial cytochrome b gene of Taenia asiatica in Dali Bai Autonomous Prefecture,Yunnan Province

目的:了解云南省大理白族自治州(简称大理州)亚洲带绦虫线粒体细胞色素b(Cytb)基因的遗传多样性。方法:2019年5月至2021年8月,在大理州血吸虫病防治研究所收治的绦虫病患者中,共采集131份带绦虫样本,涉及大理市(58份),巍山彝族回族自治县(简称巍山县,14份),弥渡县(18份),漾濞彝族自治县(简称漾濞县,24份),洱源县(17份)5个地区(即5个群体)。基于线粒体Cytb基因序列设计引物,采用PCR法扩增Cytb基因部分序列,并进行测序及同源性比对;使用MEGA 7.0、DNASP 5.10.01软件对测得序列进行分析,得到碱基组成、遗传距离、遗传多样性参数、遗传分化指数、基因流等数据。结果:131份带绦虫样本的Cytb基因扩增片段大小均为235 bp,经同源性比对均为亚洲带绦虫,A、T、G、C碱基的平均含量分别为23.8%、42.3%、24.0%、9.9%。131份亚洲带绦虫样本,共定义12个单倍型,单倍型多样性和核酸多样性分别为0.295 9和0.006 0;5个群体间的遗传分化指数和基因流范围分别为- 0.053 00~0.050 40和4.710 31~162.087 66。5个群体间的遗传距离范围为0.003 5~0.009 0,其中弥渡县与巍山县的遗传距离最大,大理市与漾濞县的遗传距离最小。结论:大理州亚洲带绦虫线粒体Cytb基因具有丰富的遗传多样性,各群体间存在频繁的基因交流,未形成显著的遗传分化。

Objective In order to investigate the genetic diversity of mitochondrial cytochrome b(Cytb)gene of Taenia asiatica(T.asiatica)in Dali Bai Autonomous Prefecture(Dali Prefecture),Yunnan Province.Methods From May 2019 to August 2021,a total of 131 samples of Taenia were collected from patients admitted to the Dali Prefecture Institute of Schistosomiasis Control,involving five locations(i.e.,five groups),including Dali City(58 samples),Weishan Yi and Hui Autonomous County(Weishan County,14 samples),Midu County(18 samples),Yangbi Yi Autonomous County(Yangbi County,24 samples)and Eryuan County(17 samples).Primers were designed based on mitochondrial Cytb gene sequence,and part of the Cytb gene sequence was amplified by PCR,then sequenced and homology comparisons were performed.MEGA 7.0 and DNASP 5.10.01 were used to analyze the measured sequence,and data such as base composition,genetic distance,genetic diversity parameters,genetic dfferentiation index and gene flow were obtained.Results The amplified fragments of Cytb gene in 131 samples of Taenia were 235 bp.After homology comparisons,they were all T.asiatica.The average contents of A,T,G and C bases were 23.8%,42.3%,24.0%and 9.9%,respectively.Of the 131 samples of T.asiatica,12 haplotypes were defined.The haplotype diversity and nucleic acid diversity were 0.2959 and 0.0060,respectively.The ranges of genetic differentiation index and gene flow among the five groups were-0.05300 to 0.05040 and 4.71031 to 162.08766,respectively.The genetic distance between the five groups ranged from 0.0035 to 0.0090,of which the genetic distance between Midu County and Weishan County was the largest,and the genetic distance between Dali City and Yangbi County was the smallest.Conclusions The mitochondrial Cytb gene of T.asiatica in Dali Prefecture has rich genetic diversity.There is frequent gene exchange among the five groups,and no significant genetic differentiation has been formed.