鼬科动物线粒体DNA控制区结构分析

利用PCR技术获得紫貂(Martes zibellina)和黄喉貂(Martes flavigula)线粒体DNA控制区全序列,并结合从GenBank中下载的9种鼬科动物相应序列,用ClustalX排序后对控制区结构进行分析,识别出延长终止序列区、中央区和保守序列区3个区域,指出了一个终止相关序列ETAS1及8个保守序列(CSB-F、E、D、C、B、1、2和3),并给出了序列通式,在CSB1和CSB2之间发现不同形式的短重复序列.此外,以狼为外类群,应用邻接法构建鼬科线粒体控制区全序列的系统进化树,结果表明:臭鼬亚科最先从鼬科中分化出来,随后剩余类群分为两大支系,即貂属种类与貂熊聚为一支,并与獾亚科的狗獾形成姐妹群;另一支为水獭亚科的物种与鼬属的林鼬形成姐妹群,再与虎鼬聚在一起,狗獾与貂属的紫貂亲缘关系最近,水獭亚科与鼬属亲缘关系最近.

Structure of the mtDNA control region and phylogeny of the Mustelidae species

Complete sequences of the mitochondrial DNA control region from Sable and Yellow-throated marten were amplified by Polymerase Chain Reaction (PCR), and were aligned by ClustalX with nine other species of Mustelidae from GenBank. According to the alignment, three domains, the extended termination associated sequence domain (ETAS), the central domain (CD) and the conserved sequence block domain (CSB), were identified in the mtDNA control region of Mustelidae. A extended termination associated sequence(ETAS1) and eight conserved sequence(CSB-F, E, D, C, B, 1, 2, 3) were identified, and mode of sequence was provided. Different kinds of short repetitive sequences were found between CSB1 and CSB2. Moreover, the phylogenetic evolution relationship of Mustelidae was analyzed using the neighbor-joining(NJ) method with the Wolf as the outgroup,. The results showed that Mephitinae was divided from Mustelidae firstly, and then the others were divided into two branches. The species of Martes and Wolverine were contained in one branch which was formed a sister group with Eurasian badger of Melinae;The species of Lutrinae and Polecat of Mustela formed a sister group, and Marbled polecat was sister to the clade of Lutrinae species and Polecat. They formed another branch. Eurasian badger has the closest relationship with the Sable of Martes, and Lutrinae has the closest relationship with Mustela.