系统发育学论文.doc

恩蚜小蜂属部分种类28S rDNA及CO1基因序列的分子进化和系统学研究 专业：生物化学与分子生物学 姓名：邢建晓 学号 摘要 本文通过对恩蚜小蜂属部分种类28S rDNA及CO1序列进行分析，重建恩蚜小蜂属的部分种类系统发育关系。使用ClustalX1.81对来源于Genbank上的27种恩蚜小蜂属28S rDNA及CO1序列片段进行了同源性比较，并利用MEGA 5.0软件计算碱基含量、颠换值、转换值、颠换比和遗传距离，采取相邻连接法、最小进化法、最大似然法构建了恩蚜小蜂属的系统发育树。结果显示，恩蚜小蜂属28SrDNA序列的保守位点为3,占总位点数的0.55%;序列变异位点为538,简约信息位点为536,占序列总位点的99.1%，转换数为113,颠换数为237,碱基的转换主要发生在TC间,转换的频率是颠换频率的0.48倍,由此可以认为恩蚜小蜂属的28SrDNA的保守性较强。恩蚜小蜂属C0I序列的保守位点为1,占总位点数的0.15%;序列变异位点为680,占总变异位点的99.7%;简约信息位点为678。其中转换数为99,颠换数为284,可见恩蚜小蜂属的C0I序列的变异率较高。 关键词：恩蚜小蜂属 28SrDNA 系统发育 Abstract This article analysis 28S rDNA and CO1 sequence of Encarsia,and reconstruct the genus part of phylogenetic relationships of Encarsia. Using ClustalX1.81 from of 27 Encarsia in Genbank compared 28 s rDNA and CO1 sequence fragments.The homology and MEGA 5.0 software is used to calculate base content,transversion value, transformation, transversion ratio and genetic distance.Taking the adjacent connection method,minimum evolution method, maximum likelihood method to construct the phylogenetic trees of the Encarsia.According to the results of Encarsia ,conservative sites of 28s sequences is 3,accounting for 0.55% of the total numbers;Sequence mutation loci is 538, contracted and information site is 536, accounting for 99.1% of the sequence of total, convert the number is 113, Britain is 237, the bases of the transformation occur between mainly in TC, the frequency of transformation is a transversion of 0.48 times, which can be thought of Encarsia of the 28s conservative is stronger. The Encarsia of C0I sequence of conservative sites is 1, accounting for 0.15% of the total numbers ;Sequence mutation sites is 680, accounting for 99.7% of the total variation sites.A simple information site is 678 which convert the number to 99. Britain is 284, Encarsia genus C0I sequence variation rate is higher. Keywords: Encarsia 28SrDNA system development 目 录 1 前言 - 1 - 1