通过扩增获得18S rRNA和叶绿体16S rRNA基因序列，测序并提交GenBank ，登录号分别是JF719285和JF719286．利用大蒜和GenBank相关序列构建系统发育树，进行分子演化分析．结果表明：大蒜18S rRNA 基因与球序韭、韭菜、茖葱等葱科植物序列相似度高；叶绿体16S rRNA基因与龙舌兰科和薯蓣科的物种序列相似度高．大蒜与葱科植物在18S rRNA序列上具有较高的同源性．18S rRNA序列在植物演化方面的区分度比16S rRNA高．

In the paper ,molecular phylogeny of Allium sativum were discussded with the analysis of rRNA gene .18S rRNA gene and chloroplast 16S rRNA gene sequences were amplified .The two rRNA genes were submitted to Genbank and the accession numbers were JF719285 and JF719286 .Gene sequences of Allium sativum was analyzed with related species in GenBank .The results showed that :Allium sativum 18S rRNA gene has a high homology with many species within Alliaceae ,such as Allium thunbergii ,Allium tuberosum and Allium victorialis .Allium sativum and Alliaceae plants has a high similarity in 18S rDNA . The discrimination accusation of 18Sr RNA sequences in plant phylogeny analysis is better than that of 16S rRNA .

探讨土壤微生物指标的变化规律,用于揭示其在岩溶土壤碳循环中的指示意义.以桂林岩溶试验场洼地、坡地和垭口这3种岩溶地貌形态下的剖面(0~10、10~20、20~30cm)土壤为研究对象,采用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)和荧光定量 PCR 相结合的方法,分析这个典型岩溶土壤剖面中的微生物多样性和丰度变化.数据显示,16S rRNA最高丰度出现在洼地,为1.32×1011拷贝·g -1,而18S rRNA最高丰度出现在垭口,为1.12×1010拷贝·g -1；洼地和垭口剖面的16S rRNA丰度随着深度的增加而降低,3种岩溶地貌形态的18S rRNA丰度均随着剖面深度的增加而降低,与土壤有机碳质量分数的变化趋势一致.但是,在 3种岩溶地貌形态中,3个16S rRNA和6个18S rRNA的多样性指数均随土壤剖面深度的增加而增大.由于16S rRNA和18S rRNA的多样性与丰度和土壤有机碳之间总体上表现出相反的变化趋势,说明微生物丰度指标在土壤碳循环中的指示意义比微生物多样性指数更重要.

The soil microbial characteristics were detected to clarify their indications in organic carbon cycle in karst system. Soil samples from three karst types (saddle, depression and slop) at 0-10 cm, 10-20 cm and 20-30 cm layers were collected in the Yaji Karst Experimental Site, a typical karst ecosystem. The microbial diversity and abundance were assayed using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and fluorescence quantitative PCR. The data showed that the highest abundance of 16S rRNA and 18S rRNA were in depression with 1. 32 × 1011 copies·g - 1 and in saddle with 1. 12 × 1010 copies·g - 1 , respectively. The abundance of 16S rRNA in saddle and depression decreased from top to bottom, while that of 18S rRNA in three karst forms decreased, which showed that the abundance changed consistently with soil organic carbon (SOC). The 3 diversity indices of 16S rRNA and 6 diversity indices of 18S rRNA increased from top to bottom in soil pro

运用16S rRNA基因序列分析法鉴定14种细菌,为该方法的临床应用奠定基础。方法:提取细菌DNA,采用通用引物PCR扩增16S rRNA基因片段并测序。将测序结果用Blastn在线软件在Nucleotide数据库中进行序列同源性比对,根据序列同源性鉴定病原细菌。结果:12种细菌可以鉴定到"种",2种细菌可以鉴定到"属"。结论:16SrRNA基因序列分析是一种有效的病原细菌鉴定方法。

Objective: To identify 14 bacteria by sequencing the 16S rRNA gene and establish the basis for clinical application in the future. Methods: DNA samples of the 14 bacteria were extracted. The 16S rRNA genes were amplified by PCR and sequenced with common primers. The sequences of the 16S rRNA genes were aligned by online software Blastn in nucleotide database. The bacteria were identified according to the homology of their 16S rRNA genes. Results: Twelve bacteria were classified to species, the other 2 bacteria were classified to genus. Conclusion: 16S rRNA gene sequence analysis is useful in identifying pathogenic bacteria.

本研究旨在利用16S rRNA基因克隆库技术分析广西富钟水牛瘤胃产甲烷菌组成及多样性。选取3头体况基本一致的健康雌性富钟水牛作为试验动物,采用机械破壁法提取瘤胃内容物总DNA,采用产甲烷菌引物Met86F/Met1340R扩增16S rRNA基因,构建16S rRNA基因克隆文库。结果表明,本试验共获得93个非嵌合体16S rRNA序列,按照97%的相似性划分为39个分类操作单元( OTU)。其中,60个序列(15个OTU)与已培养细菌16S rRNA序列相似性≥97%,占总序列的64.5%；32个序列(23个OTU)与已培养菌16S rRNA 序列相似性处于90%~(<97%)；仅有1个序列与Methanomassiliicoccus luminyensis相似性<90%。系统发育树分析表明,98.9%的序列均属于甲烷杆菌目( Methanobacteriales),部分序列与Methanobacteriales中任何已知相似序列都相隔较远,它们可能代表Methanobacteriales中新的属或种。由上述结果可见,富钟水牛瘤胃产甲烷菌以Methanobacteriales为优势菌群,其中有许多未知的产甲烷菌需进一步分离培养并对其功能进行分析。

The objective of this study was to analysis the composition and the diversity of ruminal methanogens in Guangxi Fuzhong buffaloes by using 16S rRNA gene cloning library technique. Three healthy female Fuzhong buffaloes with similar body condition were used in this study. Total DNA of ruminal contents was ex-tracted by bead-beating method. Primers of Met86F/Met1340R of methanogens were used to amplify 16S rRNA gene for the construction of 16S rRNA gene clone library. The results showed that 93 chimera-free 16S rRNA sequences were obtained in the present study. Based the 97% similarity, these sequences were assigned to 39 operational taxonomic units ( OTUs) . Among those, sixty sequences showed ≥97% sequence similarity to known species (15 OTUs, occupied 64.5% of total sequences), thirty two sequences had sequence similari-ty to known species in the range of 90% to <97% ( 23 OTUs) , and only one sequence displayed similarity <90% with Methanomassiliicoccus luminyensis. Phyloge

目的：了解浙江西天目山家畜和啮齿动物中流行的立克次体无形体属种型，分析其16S rRNA基因变异。方法从动物肝脾和血液中提取DNA，PCR扩增无形体属16S rRNA片段；测序，采用MEGA5．0软件进行序列比对和系统发生分析。结果129只动物中，1只牛、8只羊、8只啮齿动物检出无形体属16S rRNA 片段，序列比对和系统发生分析表明，检出的无形体属16S rRNA包括嗜吞噬细胞无形体、边缘无形体、中央无形体和牛无形体，还检测到变异较大的16 S rRNA基因。结论西天目山动物中存在无形体属立克次体感染，其中啮齿动物中发现的变异株可能为一种与牛无形体紧密相关的新种型。

Objective To identify Anaplasma species circulating among livestock and rodents from Xitianmu Mountain area in Zhejiang province , Southeastern China and to analyze variations regarding to their 16S rRNA gene.Methods Samples of spleen, liver and blood were collected to extract DNAs .The 16S rRNA gene fragments of Anaplasma species were amplified by using a nested PCR and then sequenced .Ho-mology analysis was conducted by using BLAST program .The multiple sequence alignment and phylogenetic analyses comparing with the sequences of other Anaplasma species in GenBank were conducted by using MEGA 5.0 software.Results The 16S rRNA gene fragments of Anaplasma were detected in 1 cattle, 8 goats, 5 Rattus confucianus, 1 Apodemus agrarius, 1 Berylmys bowersi and 1 squirrel out of 129 animals. The natural infection rate of Anaplasma was 13.2% in animals from Xitianmu Mountain area in Zhejiang . The alignment and phylogenetic analyses indicated that there were at least four Anaplasma species pre