138 resultados para 16S rRNA


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对蝮亚科(蛇岛蝮Gloydius shedaoensis Zhao、黑眉蝮Gloydius saxatilis Emelianov、乌苏里蝮Gloydius ussurriensis Emelianov、竹叶青Trimeresurus stejnegeri Schmidt和分别来自不同地区的尖吻蝮Deinagkistrodon acutus Guenther、短尾蝮Gloydius brevicaudus Stejneger各两条)6种蛇共8个个体测定、分析了约370bp线粒体12S rRNA基因序列,以游蛇科链蛇属半棱鳞链蛇Dinodon semicarinatus序列为外群构建分子系统树。

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对自然感染的水牛源的人肉孢子虫以及黄牛源人肉孢子虫DNA的18S rRNA基因的PCR扩增产物进行了测序。对所获的863 bp的18S rRNA基因分析比较表明,二者有较高的同源性,因此认为二者可能同是一种肉孢子虫——人肉孢子虫(Sarcocystis hominis Railliet and Lucet,1891)。由此推断,不仅黄牛可作为人肉孢子虫的中间宿主,水牛也可作为人肉孢子虫的中间宿主。

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DNA templates were extracted from isolates of Sarcocystis hominis-like cysts collected from cattle and water buffalo, as well as from Sarcocystis fusiformis cysts and Sarcocystis suihominis cysts. The 18S rRNA genes were amplified using DNA from a single

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Thirteen restriction endonucleases were used to investigate nucleotide sequence variation in the 18S rRNA DNA of 88 individuals from ten Sarcocystis taxa collected as cysts from their intermediate hosts, swine, cattle and water buffalo. A DNA sequence of

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The phylogenetic position of Diplura within Hexapoda has been controversial. There are three major lineages in Diplura: Campodeoidea, Projapygoidea, and Japygoidea. However, most of the previous studies were restricted to Campodeoidea and Japygoidea. Unti

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We sequenced partial mitochondrial 16S ribosomal DNA (16S rDNA) of 18 firefly species from Southwest of China. Combined with homologous sequences previously reported, phylogenetic trees including Japanese, Korean and Chinese species were reconstructed by

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高分辨率的核糖体精细结构揭示,核糖体行使功能的主体是RNA。核糖体的主要功能:催化肽键形成,识别、 选择tRNA 等都主要由rRNA 来完成。

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盾腹亚纲吸虫被认为是寄生扁形动物中古老的类群,包括盾腹科、多萼科、裂杯科和皱腹科,科间系统发育关系尚存争议。本研究收集GenBank数据库中所有的盾腹吸虫18S rRNA基因序列,测定了三种盾腹吸虫的相应序列,分别采用最大简约法和最大似然法构建分子系统发育树。结果显示,多萼科的分类地位不成立,多萼属应还原到盾腹科;盾腹科的盾腹亚科和杯盾亚科均非单系,吸槽列数可能是平行进化特征,不能反映盾腹科各亚科间的系统发育关系。建议将具有边缘器的吸槽型腹吸盘,以及不具边缘器的吸杯型和皱褶型腹吸盘分别鉴定为盾腹科、裂杯科

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东方鲀属鱼类是一个区域性分布类群,该属目前包括22个有效种,主要分布区域从日本海西部到中国沿海.本研究通过联合17种(21尾)东方鲀属鱼类的细胞色素b(1137bp)和12SrRNA(952bp)基因全序列研究了东方鲀属鱼类的系统发育关系.采用了邻接法(NJ)、最大简约法(MP)、最大似然法(ML)和Baysian方法构建了分子系统树.结果表明:(ⅰ)东方鲀属鱼类为一单系类群;(ⅱ)基于分子系统发育分析,东方鲀属鱼类可划分为6个亚群;(ⅲ)在分子水平上,本属各鱼类物种的遗传距离比较接近,这显示了其物种间分

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海洋喇叭虫Maristentordinoferus 1996年在关岛(Guam)的珊瑚暗礁上被发现 ,至今尚未阐明其确切的系统发育地位。克隆到的海洋喇叭虫的 18S ITS1 5 8SrDNA序列包括 2 2 2bp的 18S序列 ,77bp的ITS1序列和 2 2bp的 5 8S序列。比较分析了纤毛虫主要类群的ITS1序列后得出 :短的ITS1序列可能是异毛类纤毛虫的特征。根据 18S序列 ,利用邻接法构建 ,最大简约法和最大似然法构建系统发育树。其拓扑结构显示海洋喇叭虫属于异毛纲纤毛虫 ,但并不隶属喇

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通过对鲤形目鱼类 5个科的代表类群的完整线粒体 12SrRNA进行测序和分析 ,以检验目前的形态学假说。经序列比对后 ,有 10 0 0个位点 ,其中 467个位点在茎区 ,53 3个在环区 ;有 3 95个位点为变化位点 ,其中 2 67个为系统发育信息位点。采用邻接法和最大简约法进行了系统发育分析 ,其结果支持鲤科鱼类成为一个单系群 ,非鲤科的鲤形目鱼类成为另一个单系群的观点 ,这与Siebert提出的假说相一致。鲤科鱼类包含 3个主要的分支 ,即鱼丹系、鲤系和雅罗鱼系 ;但在非鲤科鲤形目鱼类中 ,其

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建立了由采自自然界中的样品、不经实验室培养而直接用于大核DNA提取和PCR反应的原位(in situ)方法;在此基础上,测定并比较了6种累枝虫(Epistylis wenrichi,E.urceolata,E.chrysemydis,E.plicatilis,E.hentscheli,E.galea)的18S-ITS1序列,结果显示:E.wenrichi,E.urceolata,E.chrysemydis,E.plicatilis和E.hentscheli间18S和ITS1区序列的碱基相似性很高,而它们与