Evidence of hybridization between Taenia saginata and Taenia asiatica
Evidence of hybridization between Taenia saginata and Taenia asiatica
复制标题
DOI：
10.1016/j.parint.2009.10.007
复制
发表时间：
2010-03-01
影响因子：
1.9
通讯作者：
Ito, Akira
中科院分区：
文献类型：
--
作者：
Okamoto, Munehiro;Nakao, Minoru;Ito, Akira
关于亚洲带绦虫的具体地位一直存在争议，有些人认为它是一个独特的物种，有些人更愿意将其视为牛带绦虫的一种。目前的平衡意见似乎是T asiatica是一个独特的物种。在这项研究中，我们进行了等位基因分析，以探讨这些密切相关的类群之间的基因交换的可能性。总共从生活在包括泰国坎恰纳布里省在内的许多地方的人类中收集了38条绦虫，其中这两个物种是同域的。利用线粒体DNA（mtDNA）多重PCR技术初步鉴定为T. asiatica（n = 20）和T. saginata（n = 18）。系统发育分析的线粒体细胞色素c氧化酶亚基I（cox 1）基因和两个核基因座，延伸因子-1 α（ef 1）和ezrin-根突蛋白（ERM）样蛋白（elp），分配所有，除了两个单独的寄生虫的多重PCR所示的物种。这两个来自坎恰纳布里的特殊个体显示出线粒体DNA和核DNA同源性之间的差异。尽管他们拥有的序列典型的T saginata cox 1基因，都是纯合子在elp基因座的等位基因之一，在T asiatica。在ef 1位点，一个个体是纯合子的等位基因在T。asiatica，而另一个是T. saginata。这些发现是两个物种之间偶尔杂交的证据，尽管不能排除保留祖先多态性的可能性。(C)2009爱思唯尔爱尔兰有限公司保留所有权利。
There has long been a debate as to the specific status of the cestode Taenia asiatica, with some people regarding it as a distinct species and some preferring to recognize it as a strain of Taenia saginata. The balance of current opinion seems to be that T asiatica is a distinct species. In this study we performed an allelic analysis to explore the possibility of gene exchange between these closely related taxa. In total, 38 taeniid tapeworms were collected from humans living in many localities including Kanchanaburi Province, Thailand where the two species are sympatric. A mitochondrial DNA (mtDNA)-based multiplex PCR tentatively identified those parasites as T. asiatica (n = 20) and T. saginata (n = 18). Phylogenetic analyses of a mitochondrial cytochrome c oxidase subunit I (cox1) gene and two nuclear loci, for elongation factor-1 alpha (ef1) and ezrin-radixin-moesin (ERM)-like protein (elp), assigned all except two individual parasites to the species indicated by multiplex PCR. The two exceptional individuals, from Kanchanaburi Province, showed a discrepancy between the mtDNA and nuclear DNA phylogenies. In spite of their possession of sequences typical of the T saginata cox1 gene, both were homozygous at the elp locus for one of the alleles found in T asiatica. At the ef1 locus, one individual was homozygous for the allele found at high frequency in T. asiatica while the other was homozygous for the major allele in T. saginata. These findings are evidence of occasional hybridization between the two species, although the possibility of retention of ancestral polymorphism cannot be excluded. (C) 2009 Elsevier Ireland Ltd. All rights reserved.