蝗总科部分种类16S rDNA的分子系统发育关系

将自测的我国直翅目蝗总科8科8个种和从互联网GenBank中检索到相关物种的线粒体基因组：16S rDNA序列片段进行同源性比较,计算核苷酸使用频率,并构建分子系统树。在获得的480bp的序列中。A T约占70．7％,G C为29．3％,颠换取代(transversion)的速率大于或接近转换取代(transition)的速率,其中188个核苷酸位点存在变异。研究结果表明：在直翅目蝗总科有差异的188bp中,属内种间的碱基序列差异仅为1．5％,科内属间为3．5％～3．6％,科间差异为4．8％～15．8％,亚目间差异达到15．2％～25．6％。分子系统树表明：科内的属和属内的种均优先聚在一起;蝗总科8科的起源关系为：锥头蝗科→瘤锥蝗科→癞蝗科→斑翅蝗科→剑角蝗科→网翅蝗科和槌角蝗科→斑腿蝗科;锥头蝗科与瘤锥蝗科关系较近,是蝗总科内最原始的类群;槌角蝗科和网翅蝗科互为姐妹群,与最进化的斑腿蝗科关系较近;蚤蝼科为独立的一支,最先分出,似为一个亚目,与现用的分类系统有明显差别;哈螽科(螽嘶总科)和蟋蟀科聚在一起为剑瓣亚目(Ensifera),蚱科和蝗总科的8科组成短瓣亚目(Caehfera),同现用的分类系统。     

Molecular identification of Chinese cultivated Porphyra (Bangiaceae, Rhodophyta) based on the rDNA internal transcribed spacer-1 sequence and random amplified polymorphic DNA markers

Porphyra yezoensis Ueda and P. tenera Kjellman are two common commercial seaweeds cultivated in China, but it is difficult to identify them routinely because they are morphologically and systematically very close. The nuclear ribosomal internal transcribed spacer-1 (ITS-1) region of nine selected Porphyra cultivars from China were sequenced and determined. Combined with some ITS-1 data from GenBank, the phylogenetic analysis inferred from the neighbour-joining method indicated that the Porphyra species in this study exhibited clear taxonomic relationships and could be identified clearly to species. Based on the results, the random amplified polymorphic DNA (RAPD) technique was applied to distinguish 12 Porphyra cultivars, some of which turn out to be different lineages of the same Porphyra species. Eight specific RAPD markers were scored and used to construct a fingerprint that could distinctly identify different Porphyra cultivars. The results suggest that both the rDNA ITS-1 sequence and RAPD markers are useful methods to identify Porphyra cultivars, and may also be valid for phylogenetic and taxonomic studies.     

16SrDNA同源性所揭示的双歧杆菌与有关细菌的亲缘关系

本研究测定了低ＧＣ含量的双歧杆菌（Ｂｉｆｉｄｏｂａｃｔｅｒｉｕｍ ｉｎｏｐｉｎａｔｕｍ）和新种Ｂ。ｔｈｅｒｍｏｃｉ．ｄｏｐｈｉｌｕｍ的１６ＳｒＤＮＡ全序列,在同另外１９个双歧杆菌及８个相关细菌的１６ＳｒＮＡ同源笥分析的基础上构建了系统发育树。结果表明：除低ＧＣ含蜈的Ｂ．ｉｎｏｐｉｎａｔｕｍ外,所有双杆菌的种在１６ＳｒＤＮＡ序列相似性≥８２％的水平上聚类为一个簇群。尽管Ｂ．ｉｎｏｐｉｎａｉｕｍ与其它     

Phylogenetic characterization of ineffective Frankia in Alnus glutinosa (L.) Gaertn. nodules from wetland soil inoculants

Ineffective Frankia endophytes were retrieved from various wet soils by using Alnus glutinosa clones as trapping plants. No pure cultures could be isolated from these ineffective nodules. Therefore, the phylogenetic position of these endophytes was determined by sequence analysis of cloned PCR products of bacterial 16S rDNA, derived from nodules. The results showed that all nodule endophytes belong to a hitherto undescribed cluster of the Frankia phylogenetic tree. The position of these uncultured ineffective Frankia nodule endophytes is different from that of the ineffective Frankia isolates derived from A. glutinosa nodules, even when originating from the same geographical location. This suggests a bias in current isolation techniques.     

基于16S rDNA和28S rDNA D2基因序列与形态特征联合分析的中国角顶叶蝉亚科系统发育研究（半翅目： 叶蝉科）

首次在国内利用28S rDNA D2区段和16S rDNA基因序列,结合50个形态特征对角顶叶蝉亚科(Deltocephalinae)［半翅目（Hemiptera）: 叶蝉科（Cicadellidae）］19个属进行系统发育分析研究。从无水乙醇浸泡保存的标本中提取基因组DNA并扩增了19个内群和1种外群Typhlocybinae［半翅目(Hemiptera): 叶蝉科(Cicadellidae)］种类的28S rDNA D2基因片段并测序,同时扩增了16S rDNA基因片段并测序11条,采用了GenBank中1个种类的16S rDNA同源序列。采用PAUP*4.0和MrBayes3.0两个分析软件和3种建树方法,利用同源28S D2 rDNA和16S rDNA两个基因序列与形态特征结合进行系统发育分析研究。分析结果表明,二叉叶蝉族Macrostelini是一个单系,并在角顶叶蝉亚科的系统发育中处于基部的位置,是内群中最原始的族;角顶叶蝉族Deltocephalini中除了纹翅叶蝉属Nakaharanus,其余各属构成单系;殃叶蝉族Euscelini内属的归属比较混乱,可能是一个并系群,属间差异有待进一步研究。隆额叶蝉族Paralimnini与顶带叶蝉族Athysanini是姐妹群。带叶蝉属Scaphoideus与纹翅叶蝉属Nakaharanus是姐妹群,二者与木叶蝉属Phlogotettix的关系最近,三者构成一个单系,建议将三者归为带叶蝉族Scaphoideini。研究结果还表明,小眼叶蝉族Xestocephalini和Balcluthini的系统发育位置不明,有待进一步研究。     

适冷溶菌酶产生菌的分子鉴定及其酶学性质的研究

采用比浊法对本试验室保存的126株南极微生物产适冷溶菌酶进行测定,发现7株菌产溶菌酶.并对其中的菌株NJ147进行ITS-5.8 S rDNA基因序列的同源性和系统发育分析,结果表明:菌株NJ147属于Debaryomyces hansenii属.该菌株所分泌溶菌酶的最适作用温度为30 ℃,在0 ℃时酶活性是最高活性的...     

基于线粒体16S rRNA基因部分序列探讨贵州9种菊头蝠(翼手目:菊头蝠科)的分子系统进化关系

依据部分线粒体16S rRNA基因序列,我们对贵州九种菊头蝠进行了分子系统进化关系研究.结果表明:马铁菊头蝠与其他菊头蝠亲缘关系较远,它可能是最原始的种类.中华菊头蝠和贵州菊头蝠聚在同一分支,表明它们之间亲缘关系非常接近,高鞍菊头蝠和贵州菊头蝠的DNA差异百分比最小(1.13%),因此认为这两个种亲缘关系也非常接近.     

Molecular phylogeny and character evolution in the Western Palaearctic Helicidae s.l. (Gastropoda: Stylommatophora)

In this study, we present a molecular phylogeny for the west Palaearctic Helicidae sensu lato based on sequence data from two mitochondrial (COI, 16S rDNA) and two nuclear (ITS-1, 18S rDNA) genes. Maximum likelihood analysis and Bayesian inference revealed well supported monophyletic clades partly conflicting traditional classifications. Based on these results, we propose the following system. The Western Palaearctic Helicidae s.l. consist of two families, Helicidae and Hygromiidae. Within the Helicidae, three well supported subfamilies can be recognised: the Helicinae, Ariantinae, and Helicodontinae. The Hygromiidae consist of three clades: the Hygromiinae, the Helicellinae, and a yet unnamed clade comprising the genera Sphincterochila and Cochlicella. We then used the phylogeny to study the evolution of anatomical, and ecological characters traditionally used for systematic classification. In the Helicidae s.l., two independent evolutionary transitions to life in xeric environments occurred, which allowed the occupation of new niches with a subsequent radiation of the Helicellinae-Cochlicella/Sphincterochila clade and the Helicinae. Whereas, the multiplication of the Glandulae mucosae is a synapomorphy of the Hygromiidae, the lovedart sac apparatus is present in all groups and thus, the trait cannot provide a synapomorphy for either families or subfamilies. Additionally, we evaluated the use of structural molecular genetic characters for taxonomic assessment. The presence of an unique loop region of the 16S rDNA gene and a short tandem repeat in the ITS-1 region provide independent evidence for the monophyly of these major two groups, and can be used for preliminary classification.     

黄颡单尾虫(粘体门,双壳目)的重描述及基于28S rDNA和ITS-5.8S序列的系统地位分析

采用形态分类学方法与以28S rDNA和ITS-5.8S序列为基础的分子系统学研究方法,对采自嘉陵江重庆市磁器口江段的黄颡单尾虫Unicauda pelteobagrusMa,1998进行了形态学和分子生物学的研究。基于28S rDNA数据探讨了黄颡单尾虫以及单尾虫属与相邻种属粘孢子虫间的系统地位;基于5.8S rDNA数据比较分析了粘孢子虫的系统地位。补充了黄颡单尾虫重庆种群形态学信息和28S rDNA、ITS-5.8S rDNA序列的分子信息。     

Shiraia sp．SUPER—H168 ITS-5．8S rDNA序列分析及产竹红菌素条件初步优化

对产竹红菌素的菌株SUPER-H168的ITS-5．8S rDNA进行了序列测定和进化树聚类分析,表明其属于竹黄属;对该菌株固态发酵产竹红菌素的条件进行了初步优化,得到的初步优化条件为玉米渣25g,麸皮5g,葡萄糖1．5g,NaNO3 0．15g,ZnSO4·7H2O 0．03g,起始含水量为50％,起始pH为7．0,培养温度为30℃。在该条件下发酵18d,竹红菌素的产量为9．37mg／g干基。     

基于线粒体16S rDNA基因的天牛科部分种类分子系统学研究(鞘翅目:天牛科)

研究测定了天牛科3亚科9种昆虫线粒体16S rDNA基因约500bp的序列,对序列的碱基组成和遗传距离进行分析。并基于16S rDNA基因序列数据,采用邻接法(NJ)和最大简约法(MP)分析天牛科3亚科分子系统发育关系。研究结果表明,2种方法得到的分子系统树其分支结果一致,可将内群分为2个分支,第1个分支包括沟胫天牛亚科和天牛亚科;第2个分支包括花天牛亚科。16SrDNA基因对天牛科亚科间系统发育的研究是有价值的。     

Three new species of Prosorhynchoides (Digenea: Bucephalidae) from Tylosurus gavialoides (Belonidae) in Moreton Bay,Queensland, Australia

We surveyed 30 individuals of Tylosurus gavialoides (Castelnau) (Belonidae) collected from Moreton Bay, Queensland, Australia, and describe three new species of Prosorhynchoides Dollfus, 1929 from them. The new species are morphologically distinct from existing Prosorhynchoides spp. and 28S and ITS-2 ribosomal DNA data further supports our morphological findings. We also conduct the first mitochondrial DNA analysis of species of Prosorhynchoides. The new species from T. gavialoides form a strongly supported clade on the basis of the two ribosomal markers, further supporting the emerging hypothesis that bucephaline clades are strongly associated with host groups. We have not observed any of the new species reported here in over 3500 surveyed individuals of other piscivorous fish in Australia, suggesting that these species are host-specific at least to belonids, if not to only T. gavialoides. Our findings support previous reports that suggest that belonids are exceptional hosts for bucephalids. We predict that further sampling of the numerous other belonid species present in Australian waters, for which nothing is known of the bucephalid fauna, will uncover further bucephalid richness.     

基于18S rDNA与ITS-5.8S rDNA对 重庆地区网状车轮虫的种内分化研究

本研究基于形态和分子数据对采自重庆地区5个地理株系的网状车轮虫(Trichodina reticulata)进行了比较研究及重描述。研究结果表明,网状车轮虫不同株系表现出不同的表型分化,含形态略有不同的齿体及有或无中央颗粒,因而具有明显的种内形态多样性。不同地理株系网状车轮虫的18S rDNA序列相似度在99.0%~100%之间,遗传距离为0.000~0.008,并在三大变异区(V4、V5与V7)均具一致的二级结构,表明不同株系的18Sr DNA相似度与遗传距离均属种内水平。综合18SrDNA和ITS-5.8S rDNA的变异位点和系统发育对种内分歧的研究分析显示,来自不同地理分布和宿主的网状车轮虫株系皆因相同的变异位点而聚为一枝,以此推断网状车轮虫的种内分化主要受其基因的影响,地理分布与宿主差异等环境影响在目前的种群分化阶段暂未突显。此外,本研究进一步验证了中央颗粒不能作为网状车轮虫的主要鉴别性特征的观点。     

利用转座系统在葡糖杆菌中表达山梨糖脱氢酶

目的：利用Mini—Tn5转座系统在葡糖杆菌中表达山梨糖脱氢酶（SDH）。方法：分离得到从山梨醇产糖的快生型小菌Y25K2,利用PCR方法扩增并分析快生型小菌的16SrDNA;构建pUT-mini—Tn5-Tet转座载体,将SDH基因（sdh）插入该载体,利用接合转移,将sdh整合至快生型小菌Y25K2的染色体,通过Western印迹检测SDH的表达。结果：16SrDNA鉴定结果初步表明快生型小菌为葡糖杆菌;构建得到pUT-mini—Tn5-Tet-sdh,将sdh整合至快生型菌Y25K2基因组,并检测到其在快生型小菌Y25K2中的表达。结论：利用Mini—Tn5转座系统在葡糖杆菌中表达了山梨糖脱氢酶。