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941.
Eight spotted fever group (SFG) rickettsiae isolated from ticks in Japan were classified by phylogenetic analysis based on the nucleotide sequences of both the citrate synthase-encoding gene (gltA) and 190-kDa antigen-encoding gene (rOmpA). In the phylogenetic tree of gltA, strains DT-1 and FLA-1 isolated from the Dermacentor taiwanensis and Haemaphysalis frava ticks, respectively, were placed as Rickettsia japonica, and strains IO-1, IO-2, IO-25, IM-1 and IP-2 from genus Ixodes ticks were placed as Rickettsia helvetica. Strain AT-1 isolated from the Amblyomma testudinarium belonged to the cluster including Rickettsia akari, Rickettsia australis and Rickettsia felis. In the phylogenetic tree of the rOmpA, strains DT-1 and FLA-1 were placed as R. japonica, and strain AT-1 belonged to the cluster including Rickettsia cooleyi and the symbiont of Ixodes scapularis. The rOmpA fragments of 5 Ixodes isolates could not be amplified by PCR. The present study showed that strains DT-1 and FLA-1 were genotypically identical to R. japonica, and 5 Ixodes isolates were associated with the R. helvetica. Based on previous genotypic and antigenic data, and the phylogenetic analysis presented here, strain AT-1 should be considered as a new species among SFG rickettsiae.  相似文献   
942.
We completed phylogenetic analysis of the major non-coding region of the mitochondrial DNA (mtDNA) from 159 animals of eight Euro-American and six East Asian domesticated pig breeds and 164 Japanese and five European wild boars. A total of 62 mtDNA haplotypes were detected. Alignment of these regions revealed nucleotide variations (including gaps) at 73 positions, including 58 sites with transition nucleotide substitutions, and two transversion substitutions. Phylogenetic analysis of the sequences could not organize domestic pig breeds into discrete clusters. In addition, many of the haplotypes found in members of diverged clustering groups were found primarily in Euro-American pig breeds, indicating extensive introgression of Asian domestic pigs into European breeds. Furthermore, phylogenetic analysis allocated the DNA sequences of non-coding regions into two different groups, and the deepest branchpoint of this porcine phylogeny corresponded to 86 000-136 000 years before present. This time of divergence would predate the historical period when the pig is thought to have been domesticated from the wild boar.  相似文献   
943.
Possibilities to create an efficient network of areas for the conservation of Iberian dung-beetle biodiversity were investigated. Data were taken from BANDASCA, a 15,740 record dung-beetle database with information for 101,996 specimens. The greatest species richness and phylogenetic diversity are found in the Iberian Central System cordilleras, while those of range-size rarity are in the southernmost corner of the Iberian Peninsula and in the coastal plains of the Guadalquivir basin. Additionally, broad regional score trends of these variables reach a maximum in a smaller northeastern, and a larger southeastern region (Baetic and sub-Baetic mountains). Major Central and Southern Spain dung-beetle hotspots contain many of the UTM grid cells which delimit the near-minimum-set of areas hosting maximum dung-beetle biodiversity scores. They are viewed as the nucleus of a potential network of reserves. A UTM grid cell (30TXK1) where Onthophagus albarracinus, an endemic and demographically rare species inhabits the Sierra of Albarracín and Montes Universales, was detected as an irreplaceable area. Because of recent land use changes and rapid human-induced habitat transformation threatening dung-beetle fauna, caution should be taken not to recommend an in memoriam network of areas no longer hosting a fauna extinct today. The abandoning of traditional herding management in Europe threatens the preservation of grasslands where dung-feeding beetles play a major ecological role in maintaining pasture quality and livestock health. A return to more traditional herding methods would require stable dung-beetle populations. Any insect conservation planning in Spain would benefit from more biogeographical information for other insect groups.  相似文献   
944.
Soil was sampled to a distance of 2.5 mm beneath a root mat of oilseed rape (Brassica napus) in a model rhizosphere system. DNA was extracted and the 16S rDNA amplified, cloned and sequenced. Phylogenetic analysis of these sequences with those held on-line, revealed that 37% of the clones fell within the Holophaga / Acidobacterium phylum, 17% were within the proteobacteria, 14% of the clones were close relatives of Bacillus megaterium and 5% were related to Verrucomicrobium spinosum. An additional eleven clones (21%) could not be assigned to any known phylum and may represent novel bacterial lineages. This study highlights the diverse nature of rhizosphere soils and reinforces the role that molecular approaches play in unravelling such diversity.  相似文献   
945.
中国绒山羊遗传多样性现状和系统发生关系的微卫星分析   总被引:7,自引:1,他引:6  
为了调查中国绒山羊遗传资源现状, 作者应用联合国粮农组织和国际家畜研究所推荐的19对微卫星引物并结合荧光PCR技术, 对9个中国地方产绒山羊群体和1个西非山羊品种进行了遗传多样性检测。14个微卫星座位在10个山羊群体中显示为高度多态, 可作为山羊遗传多样性分析的有效标记。多态信息含量和遗传杂合度等数据表明: 目前中国地方产绒山羊群体的遗传多样性较为丰富, 并且大部分保种场较好地保存了这些地方资源。采用非加权配对算术平均法构建的聚类图和采用主成分分析法得到的散点图均显示, 中国山羊与西非山羊为不同的2类; 中国产绒山羊中河谷山羊、河西绒山羊与其他山羊的遗传距离较远; 其他山羊又大致分为2类: 一类由辽宁绒山羊、新疆山羊、柴达木山羊、陕北山羊组成, 另一类由内蒙古绒山羊组成。此研究结果为开展我国地方绒山羊种质特性研究及资源保护和利用提供了科学依据。  相似文献   
946.
A phylogenetic tree was constructed on the basis of the amino acid sequences of the known cyclodextrin glucanotransferases (CDGTs), including those deduced from the nucleotide sequences ofBacillus sp. strain 6.6.3 andPaenibacillus macerans IB-7 genes encoding α- and β-CDGTs. The tree clearly demonstrates the existence of distinct phylogenetic groups of CDGT-producing microorganisms and the divergence of the α-, β-, and γ-CDGT produced by microorganisms from the generaBacillus, Paenibacillus, Brevibacillus, andThermoanaerobacter from a common ancestor, whereas the CDGT ofKlebsiella pneumoniae is independent and results from the convergence of different ancestors. The degree of homology of the leader peptide sequences of CDGTs may serve as a criterion of intraspecies relatedness between CDGT-producing microorganisms.  相似文献   
947.
XJ-160病毒为辛德毕斯病毒新亚型   总被引:10,自引:4,他引:6  
XJ-160病毒是我国首次分离的辛德毕斯病毒,在对其全基因组核苷酸序列测定的基础上,对病毒基因组序列、病毒同源性和病毒系统进化等进行了较为详细的分析,结果表明:XJ-160病毒具有典型的甲病毒属德毕斯病毒的序列特征。该病毒nsp3蛋白基因中11处制失及两处插入(4517 ̄5485),涉及90年核苷酸。核苷酸序列的系统进化分析表明,XJ-160病毒属于辛德毕斯病毒欧洲/非洲亚组。病毒全基因组核苷酸序  相似文献   
948.
DNA似近距离及进化时间的估算   总被引:1,自引:0,他引:1  
在似近分析和Nei氏遗传距离的基础上,给出了DNA似近距离计算公式,并以DNA似近距离估算类群间的分歧时间(进化时间),应用10种限制内切酶对猕猴属(genus Macaca)内5个种mtDNA的切点数据计算了这5个种的DNA似近距离和进化时间,比较由DNA似近距,遗传距离构建的歧化树和Fooden及Delson的形态歧化树表明,除遗传距离的歧化树外,其它三种歧化树都有一个共同点,就是熊猴(M.a  相似文献   
949.
杨前勇  叶俊华  任军  谢爱芳  徐波 《遗传》2006,28(3):357-361
犬的驯养迄今约有1万多年,由于不同环境和不同目的人工选择形成了犬品种间或品种内极丰富的毛色多样性,经证实,这些犬的很多毛色类型与MC1R相关 ,MC1R在一些物种中有同源基因 本文阐述了犬MC1R多态性研究进展,并选择其它9个有代表性的哺乳动物物种与犬MC1R同源基因进行了比较,以此建立系统发育树。结果显示,10个物种的MC1R基因的分子进化关系与物种的经典分类学地位基本相符。   相似文献   
950.
10个地方猪群体的系统聚类分析   总被引:5,自引:0,他引:5  
王昕  陈宏  曹红鹤 《遗传》2005,27(5):715-718
利用微卫星标记技术分析了中国10个地方猪群体的亲缘关系。结果表明:不同的聚类方法导致的结果不同,根据Nei’s距离所得的NJ聚类结果与实际情况较为符合,它将10个地方猪群体分为3个类群:五指山小型猪、滇南小耳猪、贵州小型香猪及其近交系4个小型猪为一类群:沂蒙黑猪、汉中黑猪与荣昌猪为一个类群;二花脸猪、金华猪与巴马香猪近交系为一个类群。  相似文献   
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