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Sample records for 16s ribosomal dna

  1. Testing the potential of a ribosomal 16S marker for DNA metabarcoding of insects.

    Science.gov (United States)

    Elbrecht, Vasco; Taberlet, Pierre; Dejean, Tony; Valentini, Alice; Usseglio-Polatera, Philippe; Beisel, Jean-Nicolas; Coissac, Eric; Boyer, Frederic; Leese, Florian

    2016-01-01

    Cytochrome c oxidase I (COI) is a powerful marker for DNA barcoding of animals, with good taxonomic resolution and a large reference database. However, when used for DNA metabarcoding, estimation of taxa abundances and species detection are limited due to primer bias caused by highly variable primer binding sites across the COI gene. Therefore, we explored the ability of the 16S ribosomal DNA gene as an alternative metabarcoding marker for species level assessments. Ten bulk samples, each containing equal amounts of tissue from 52 freshwater invertebrate taxa, were sequenced with the Illumina NextSeq 500 system. The 16S primers amplified three more insect species than the Folmer COI primers and amplified more equally, probably due to decreased primer bias. Estimation of biomass might be less biased with 16S than with COI, although variation in read abundances of two orders of magnitudes is still observed. According to these results, the marker choice depends on the scientific question. If the goal is to obtain a taxonomic identification at the species level, then COI is more appropriate due to established reference databases and known taxonomic resolution of this marker, knowing that a greater proportion of insects will be missed using COI Folmer primers. If the goal is to obtain a more comprehensive survey the 16S marker, which requires building a local reference database, or optimised degenerated COI primers could be more appropriate. PMID:27114891

  2. Clinical identification of bacteria in human chronic wound infections: culturing vs. 16S ribosomal DNA sequencing

    Directory of Open Access Journals (Sweden)

    Rhoads Daniel D

    2012-11-01

    Full Text Available Abstract Background Chronic wounds affect millions of people and cost billions of dollars in the United States each year. These wounds harbor polymicrobial biofilm communities, which can be difficult to elucidate using culturing methods. Clinical molecular microbiological methods are increasingly being employed to investigate the microbiota of chronic infections, including wounds, as part of standard patient care. However, molecular testing is more sensitive than culturing, which results in markedly different results being reported to clinicians. This study compares the results of aerobic culturing and molecular testing (culture-free 16S ribosomal DNA sequencing, and it examines the relative abundance score that is generated by the molecular test and the usefulness of the relative abundance score in predicting the likelihood that the same organism would be detected by culture. Methods Parallel samples from 51 chronic wounds were studied using aerobic culturing and 16S DNA sequencing for the identification of bacteria. Results One hundred forty-five (145 unique genera were identified using molecular methods, and 68 of these genera were aerotolerant. Fourteen (14 unique genera were identified using aerobic culture methods. One-third (31/92 of the cultures were determined to be Staphylococcus aureus, Pseudomonas aeruginosa, and Enterococcus faecalis with higher relative abundance scores were more likely to be detected by culture as demonstrated with regression modeling. Conclusion Discordance between molecular and culture testing is often observed. However, culture-free 16S ribosomal DNA sequencing and its relative abundance score can provide clinicians with insight into which bacteria are most abundant in a sample and which are most likely to be detected by culture.

  3. Unexpected Diagnosis of Cerebral Toxoplasmosis by 16S and D2 Large-Subunit Ribosomal DNA PCR and Sequencing

    DEFF Research Database (Denmark)

    Kruse, Alexandra Yasmin Collin; Kvich, Lasse Andersson; Eickhardt-Dalbøge, Steffen Robert;

    2015-01-01

    The protozoan parasite Toxoplasma gondii causes severe opportunistic infections. Here, we report an unexpected diagnosis of cerebral toxoplasmosis. T. gondii was diagnosed by 16S and D2 large-subunit (LSU) ribosomal DNA (rDNA) sequencing of a cerebral biopsy specimen and confirmed by T. gondii...

  4. 16S/18S ribosomal DNA clone library analysis of rumen microbial diversity

    International Nuclear Information System (INIS)

    The rumen contains a complex ecosystem where billions of bacteria, archaea, protozoa and fungi reside. This diverse microbiota is well adapted to live in the rumen and play an important role in the digestion of feed and nutrient supply to the host in the form of microbial protein and volatile fatty acids. It is estimated that the rumen microbial population consists of about 106 protozoa/ml, 103-107 fungi/ml, 1010 bacteria/ml, and 109 methanogens/ml. To better understand the complex relationships in the rumen, it is necessary to gain an insight into the diversity of the rumen microbes and how the quantity and composition of rumen micro-organisms are altered by a number of different host factors such as age, genetics and diet. In the past, the diversity of micro-organisms from the digestive tracts of domesticated ruminants has been identified by classical microbiological techniques. However, given the fastidious growth requirements of rumen micro-organisms, it is reasonable to concede that the culture-dependent methods may select against some species, or taxonomic groups, leading researchers to underestimate the microbial diversity that is actually present in the rumen. In fact, it has been speculated that 90% of micro-organisms in nature have escaped traditional cultivation methods. Therefore, a major challenge in microbial ecology has been to assess the diversity and structure of natural microbial communities. The field of molecular biology has advanced with many innovative technological breakthroughs. The ability to extract and to isolate high-molecular weight DNA from rumen digesta, PCR amplify genes from specific microbial groups and obtain gene sequence data is now a routine event. The small subunit ribosomal RNA (SSU-rRNA) gene, called 16S in prokaryotes and 18S in eukaryotes, is the most widely used molecular marker to presumptively identify morphologically indistinguishable species, to infer their phylogenetic relationships, and to elucidate microbial

  5. 16S partial gene mitochondrial DNA and internal transcribed spacers ribosomal DNA as differential markers of Trichuris discolor populations.

    Science.gov (United States)

    Callejón, R; Halajian, A; de Rojas, M; Marrugal, A; Guevara, D; Cutillas, C

    2012-05-25

    Comparative morphological, biometrical and molecular studies of Trichuris discolor isolated from Bos taurus from Spain and Iran was carried out. Furthermore, Trichuris ovis isolated from B. taurus and Capra hircus from Spain has been, molecularly, analyzed. Morphological studies revealed clear differences between T. ovis and T. discolor isolated from B. taurus but differences were not observed between populations of T. discolor isolated from different geographical regions. Nevertheless, the molecular studies based on the amplification and sequencing of the internal transcribed spacers 1 and 2 ribosomal DNA and 16S partial gene mitochondrial DNA showed clear differences between both populations of T. discolor from Spain and Iran suggesting two cryptic species. Phylogenetic studies corroborated these data. Thus, phylogenetic trees based on ITS1, ITS2 and 16S partial gene sequences showed that individuals of T. discolor from B. taurus from Iran clustered together and separated, with high bootstrap values, of T. discolor isolated from B. taurus from Spain, while populations of T. ovis from B. taurus and C. hircus from Spain clustered together but separated with high bootstrap values of both populations of T. discolor. Furthermore, a comparative phylogenetic study has been carried out with the ITS1and ITS2 sequences of Trichuris species from different hosts. Three clades were observed: the first clustered all the species of Trichuris parasitizing herbivores (T. discolor, T. ovis, Trichuris leporis and Trichuris skrjabini), the second clustered all the species of Trichuris parasitizing omnivores (Trichuris trichiura and Trichuris suis) and finally, the third clustered species of Trichuris parasitizing carnivores (Trichuris muris, Trichuris arvicolae and Trichuris vulpis).

  6. Conservative fragments in bacterial 16S rRNA genes and primer design for 16S ribosomal DNA amplicons in metagenomic studies

    KAUST Repository

    Wang, Yong

    2009-10-09

    Bacterial 16S ribosomal DNA (rDNA) amplicons have been widely used in the classification of uncultured bacteria inhabiting environmental niches. Primers targeting conservative regions of the rDNAs are used to generate amplicons of variant regions that are informative in taxonomic assignment. One problem is that the percentage coverage and application scope of the primers used in previous studies are largely unknown. In this study, conservative fragments of available rDNA sequences were first mined and then used to search for candidate primers within the fragments by measuring the coverage rate defined as the percentage of bacterial sequences containing the target. Thirty predicted primers with a high coverage rate (>90%) were identified, which were basically located in the same conservative regions as known primers in previous reports, whereas 30% of the known primers were associated with a coverage rate of <90%. The application scope of the primers was also examined by calculating the percentages of failed detections in bacterial phyla. Primers A519-539, E969- 983, E1063-1081, U515 and E517, are highly recommended because of their high coverage in almost all phyla. As expected, the three predominant phyla, Firmicutes, Gemmatimonadetes and Proteobacteria, are best covered by the predicted primers. The primers recommended in this report shall facilitate a comprehensive and reliable survey of bacterial diversity in metagenomic studies. © 2009 Wang, Qian.

  7. Evaluation of Partial 16S Ribosomal DNA Sequencing for Identification of Nocardia Species by Using the MicroSeq 500 System with an Expanded Database

    OpenAIRE

    Cloud, Joann L.; Patricia S Conville; Croft, Ann; Harmsen, Dag; Witebsky, Frank G.; Carroll, Karen C.

    2004-01-01

    Identification of clinically significant nocardiae to the species level is important in patient diagnosis and treatment. A study was performed to evaluate Nocardia species identification obtained by partial 16S ribosomal DNA (rDNA) sequencing by the MicroSeq 500 system with an expanded database. The expanded portion of the database was developed from partial 5′ 16S rDNA sequences derived from 28 reference strains (from the American Type Culture Collection and the Japanese Collection of Microo...

  8. Quantitative Selective PCR of 16S Ribosomal DNA Correlates Well with Selective Agar Plating in Describing Population Dynamics of Indigenous Pseudomonas spp. in Soil Hot Spots

    OpenAIRE

    Johnsen, Kaare; Enger, Øivind; Jacobsen, Carsten S.; Thirup, Laila; Torsvik, Vigdis

    1999-01-01

    We used a quantitative PCR method targeting 16S ribosomal DNA using competitive PCR for specific detection of indigenous Pseudomonas DNA in soil hot spots. The amount of Pseudomonas DNA corresponded to the number of culturable Pseudomonas bacteria on Gould’s S1 agar. This represents the first use of PCR for quantification of indigenous bacteria in more than one sample of soil.

  9. Phylogeny of fireflies (Coleoptera: Lampyridae) inferred from mitochondrial 16S ribosomal DNA, with references to morphological and ethological traits

    Institute of Scientific and Technical Information of China (English)

    LI Xueyan; YANG Shuang; XIE Meng; LIANG Xingcai

    2006-01-01

    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 neighbor-joining, maximum parsimony and Bayesian methods. All reconstructions agree on most nodes of the trees. Monophyly of Lampyridae is not supported because Rhagophthalmus ohbai in Rhagophthalmidae is included within it. Lamprigera, a genus placed unreliably in Lampyrinae, shows a close relationship to Amydetinae. Monophyly of Luciolinae is not supported because Pristolycus sagulatus (Lampyrinae) is included within it. In the Luciolinae, monophyly of Curtos and Hotaria is well established, respectively, but both morphological and molecular data continue to indicate that Luciola is not monophyletic and its subdivision is indeed necessary. Within the Lampyrinae, both Pyrocoelia and Diaphanes are not monophyletic, but monophyly of Pyrocoelia + Diaphanes is well supported. Phylogeny of Diaphanes is discussed for the first time. Generic placement of a newly discovered species (Diaphanes pectinealis Li et Liang)sharing some characters of Pyrocoelia and Diaphanes challenges the delimitation of these two similar genera. With references to the firefly mating systems, we suggest that more emphases should be placed on those sexually selected characters such as antennal structure in taxonomy of Lampyridae.

  10. Identification of Nonpoint Sources of Fecal Pollution in Coastal Waters by Using Host-Specific 16S Ribosomal DNA Genetic Markers from Fecal Anaerobes

    OpenAIRE

    Bernhard, Anne E.; Field, Katharine G.

    2000-01-01

    We describe a new PCR-based method for distinguishing human and cow fecal contamination in coastal waters without culturing indicator organisms, and we show that the method can be used to track bacterial marker sequences in complex environments. We identified two human-specific genetic markers and five cow-specific genetic markers in fecal samples by amplifying 16S ribosomal DNA (rDNA) fragments from members of the genus Bifidobacterium and the Bacteroides-Prevotella group and performing leng...

  11. Metagenomic analysis targeted on the 16S ribosomal DNA to study the quality of meat : a example with raw minced beef meat

    OpenAIRE

    Delhalle, Laurent; Taminiau, Bernard; Nezer, Carine; Daube, Georges

    2013-01-01

    Introduction: Steak tartare is a popular meat dish in Belgium and some other European countries. This meat preparations due to their raw nature, is highly sensitive to bacterial spoilage. A better understanding of the bacterial content of this product will thus be insightful to control the risk of spoilage. Metagenomics targeted on the 16S ribosomal DNA has appeared as a powerful tool to study bacterial composition of food samples. The aim of this study is to identify the bacterial populatio...

  12. Development of Amplified 16S Ribosomal DNA Restriction Analysis for Identification of Actinomyces Species and Comparison with Pyrolysis-Mass Spectrometry and Conventional Biochemical Tests

    OpenAIRE

    Hall, Val; O’Neill, G. L.; Magee, J T; Duerden, B I

    1999-01-01

    Identification of Actinomyces spp. by conventional phenotypic methods is notoriously difficult and unreliable. Recently, the application of chemotaxonomic and molecular methods has clarified the taxonomy of the group and has led to the recognition of several new species. A practical and discriminatory identification method is now needed for routine identification of clinical isolates. Amplified 16S ribosomal DNA restriction analysis (ARDRA) was applied to reference strains (n = 27) and clinic...

  13. Endodontic bacteria from primary and persistent endodontic lesions in Chinese patients as identified by cloning and 16S ribosomal DNA gene sequencing

    Institute of Scientific and Technical Information of China (English)

    LI Xin; ZHU Xiao-fei; ZHANG Cheng-fei; Peter Cathro; CJ Seneviratne; SHEN Song

    2013-01-01

    Background Few literatures pertain to the 16S ribosomal DNA (16S rDNA) analysis of bacteria contributing to primary and persistent endodontic lesions,with no information available for the Chinese population.As such,we investigated endodontic bacteria associated with primary and persistent endodontic lesions in adult Chinese patients living in Beijing,China using 16S rDNA gene sequencing techniques.Methods Endodontic microbial samples were obtained from fourteen adult Chinese patients and subjected to DNA extraction.Pllymerase chain reaction (PCR) products were cloned and 100 clones from each generated library were randomly selected.Purified plasmid DNA with 16S rDNA gene inserts was sequenced,and the sequences were searched against GenBank databases using the BLASTN algorithm.Only significant identification with the highest-scored BLAST result and 99% minimum similarity was considered for phylotyping.Results More than 150 taxa were obtained.Primary endodontic infection was mainly associated with Burkholderia cepacia,Actinomyces,Aranicola spp.and Streptococcus sanguinis,whilst Burkholderia cepacia was predominant in the persistent endodontic infections.Conclusion There is a difference in the species profile associated with endodontic infections of Chinese patients living in Beiiing in comoarison to other geographical or ethnic reports.

  14. Double trouble for grasshopper molecular systematics: intra-individual heterogeneity of both mitochondrial 12S-valine-16S and nuclear internal transcribed spacer ribosomal DNA sequences in Hesperotettix viridis

    Science.gov (United States)

    Hesperotettix viridis grasshoppers (Orthoptera: Acrididae:Melanoplinae) exhibit intra-individual variation in both mitochondrial 12S-valine-16S and nuclear internal transcribed spacer (ITS) ribosomal DNA sequences. These findings violate core assumptions underlying DNA sequence data obtained via pol...

  15. Differentiation of Actinobacillus pleuropneumoniae strains by sequence analysis of 16S rDNA and ribosomal intergenic regions, and development of a species specific oligonucleotide for in situ detection

    DEFF Research Database (Denmark)

    Fussing, Vivian; Paster, Bruce J.; Dewhirst, Floyd E.;

    1998-01-01

    . The larger RIS's were different between the 3 species tested. The sequence of the 16S ribosomal gene was determined for 8 serotypes of A. pleuropneumoniae. These sequences showed only minor base differences, indicating a close genetic relatedness of these serotypes within the species. An oligonucleotide DNA...... probe designed from the 16S rRNA gene sequence of A. pleuropneumoniae was specific for all strains of the target species and did not cross react with A. lignieresii, the closest known relative of A. pleuropneumoniae. This species-specific DNA probe labeled with fluorescein was used for in situ....... pleuropneumoniae. Amplification and sequence analysis of the 16S-23S rDNA ribosomal intergenic sequence (RIS) from the three species showed the existence of two RIS's, differing by about 100 bp. Both sequences contained a region resembling the ribonuclease III cleavage site found in Escherichia coli. The smaller...

  16. Molecular phylogeny of the butterfly tribe Satyrini (Nymphalidae: Satyrinae) with emphasis on the utility of ribosomal mitochondrial genes 16s rDNA and nuclear 28s rDNA.

    Science.gov (United States)

    Yang, Mingsheng; Zhang, Yalin

    2015-07-09

    The tribe Satyrini is one of the most diverse groups of butterflies, but no robust phylogenetic hypothesis for this group has been achieved. Two rarely used 16s and 28s ribosomal and another seven protein-coding genes were used to reconstruct the phylogeny of the Satyrini, with further aim to evaluate the informativeness of the ribosomal genes. Our maximum parsimony (MP), maximum likelihood (ML) and Bayesian inference (BI) analyses consistently recovered three well-supported clades for the eleven sampled subtribes of Satyrini: clade I includes Eritina and Coenonymphina, being sister to the clade II + clade III; clade II contains Parargina, Mycalesina and Lethina, and the other six subtribes constitute clade III. The placements of the taxonomically unstable Davidina Oberthür and geographically restricted Paroeneis Moore in Satyrina are confirmed for the first time based on molecular evidence. The close relationships of Callerebia Butler, Loxerebia Watkins and Argestina Riley are well-supported. We suggest that Rhaphicera Butler belongs to Lethina. The partitioned Bremer support (PBS) values of MP analysis show that the 16s rDNA contributes well to the nodes representing all the taxa from subtribe to species levels, and the 28s rDNA is informative at the subtribe level. Furthermore, our ML analyses show that the ribosomal genes 16s rDNA and 28s rDNA are informative, because most node support values are lower in the ML tree after the removal of them than that in ML tree constructed based on the full nine-gene dataset. This indicates that some other ribosomal genes should be tentatively used through combining with traditionally used protein-coding genes in further analysis on phylogeny of Satyrini, providing that proper representatives are sampled.

  17. Fluorescence-based Multiplex PCR-Single Strand Conformation Polymorphism (SSCP) Analysis of 16S Ribosomal DNA Using Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    高鹏; 韩英; 许国旺; 赵春霞; 戴兵; 李萍; 王运铎; 温杰; 徐维家

    2004-01-01

    The rRNA genetic locus is found in all prokaryotic organisms, and is highly conservative, although its relatively stable variations are found frequently in different bacteria. The utility of this locus as a taxonomic and phylogenetic tool has been reported widely. This study, aimed at 16S rRNA gene ( 16S rDNA) and with the help of biomolecular methods, attempted to achieve the goal of rapid identification of common pathogens In this study, 333 clinical isolated pathogenic bacteria were collected。 Two pairs of primers were chosen and labeled with different fluorescent dyes and then used to amplify the genomic DNA extracted from bacteria. The PCR products were then detected by capillary electrophoresis-single strand conformation polymorphism (CE-SSCP) . In order to pursue higher resolution and peak-separation effect, a high efficient separating medium, liner polyacrylamidedel (LPA), was put to use in this study. Finally, every bacteria colony generated distinct patterns from each other, which were easily to be used for identification.These results indicated that PCR-CE-SSCP was a rapid identification method for bacterial identification, with the aspects of high efficiency and high precision. Compared with traditional method, this technology is of great utility for clinical use especially for its high sensitivity.

  18. Sequence and secondary structure of the mitochondrial 16S ribosomal RNA gene of Ixodes scapularis.

    Science.gov (United States)

    Krakowetz, Chantel N; Chilton, Neil B

    2015-02-01

    The complete DNA sequences and secondary structure of the mitochondrial (mt) 16S ribosomal (r) RNA gene were determined for six Ixodes scapularis adults. There were 44 variable nucleotide positions in the 1252 bp sequence alignment. Most (95%) nucleotide alterations did not affect the integrity of the secondary structure of the gene because they either occurred at unpaired positions or represented compensatory changes that maintained the base pairing in helices. A large proportion (75%) of the intraspecific variation in DNA sequence occurred within Domains I, II and VI of the 16S gene. Therefore, several regions within this gene may be highly informative for studies of the population genetics and phylogeography of I. scapularis, a major vector of pathogens of humans and domestic animals in North America.

  19. Characterization of Mycoplasma hyosynoviae strains by amplified fragment length polymorphism analysis, pulsed-field gel electrophoresis and 16S ribosomal DNA sequencing

    DEFF Research Database (Denmark)

    Kokotovic, Branko; Friis, N.F.; Ahrens, Peter

    2002-01-01

    , were investigated by analysis of amplified fragment length polymorphisms of the Bgl II and Mfe I restriction sites and by pulsed-field gel electrophoresis of a Bss HII digest of chromosomal DNA. Both methods allowed unambiguous differentiation of the analysed strains and showed similar discriminatory...

  20. 16S rDNA序列技术分析鉴定颗粒污泥中的微生物%Application of 16S rDNA Ribosomal RNA Approach for the Analysis and Identification of Bacterium in Granular Sludge

    Institute of Scientific and Technical Information of China (English)

    宋文哲; 陈竹; 陈元彩; 胡勇有

    2013-01-01

    Both Eubacteria and Archaea community diversity and dynamicity were studied during PCP - degrading micro - aerobic granular sludge cultivation using 16S rDNA ribosomal RNA approach. Main bands of DGGE were compared with sequences. The results showed that Eubacteria and Archaea community were closely related to uncultured microorganisms. Compared the relative quantity change of different bacteria, there were aerobic, micro -aerobic and anaerobic bactera in micro - aerobic granular sludge simultaneously. After granular sludge was domesticated by PCP, the dominant Eubacteria and Archaea for PCP degradation were related to Proteobacteria, Sphin-gomonas, Methanogenic bacterium and so on.%采用16S rDNA序列分析技术对降解五氯酚的微氧颗粒污泥形成过程中真细菌和古细菌的种群多样性和动态变化进行了研究.通过对DGGE主要条带进行序列比对,发现颗粒污泥中真细菌和古细菌都与不可培养的微生物相似性高,微氧颗粒污泥中同时存在好氧菌、微氧菌和厌氧菌.通过比较不同菌的相对数量变化发现五氯酚驯化后的颗粒污泥中产生了一系列对五氯酚降解有利的优势细菌和古菌,如Proteobacteria、Sphingomonas、Methanogenic bacterium等.

  1. Genotypic Characterization of Bradyrhizobium Strains Nodulating Endemic Woody Legumes of the Canary Islands by PCR-Restriction Fragment Length Polymorphism Analysis of Genes Encoding 16S rRNA (16S rDNA) and 16S-23S rDNA Intergenic Spacers, Repetitive Extragenic Palindromic PCR Genomic Fingerprinting, and Partial 16S rDNA Sequencing

    OpenAIRE

    Vinuesa, Pablo; Rademaker, Jan L. W.; de Bruijn, Frans J.; Werner, Dietrich

    1998-01-01

    We present a phylogenetic analysis of nine strains of symbiotic nitrogen-fixing bacteria isolated from nodules of tagasaste (Chamaecytisus proliferus) and other endemic woody legumes of the Canary Islands, Spain. These and several reference strains were characterized genotypically at different levels of taxonomic resolution by computer-assisted analysis of 16S ribosomal DNA (rDNA) PCR-restriction fragment length polymorphisms (PCR-RFLPs), 16S-23S rDNA intergenic spacer (IGS) RFLPs, and repeti...

  2. [Characterization of Black and Dichothrix Cyanobacteria Based on the 16S Ribosomal RNA Gene Sequence

    Science.gov (United States)

    Ortega, Maya

    2010-01-01

    My project focuses on characterizing different cyanobacteria in thrombolitic mats found on the island of Highborn Cay, Bahamas. Thrombolites are interesting ecosystems because of the ability of bacteria in these mats to remove carbon dioxide from the atmosphere and mineralize it as calcium carbonate. In the future they may be used as models to develop carbon sequestration technologies, which could be used as part of regenerative life systems in space. These thrombolitic communities are also significant because of their similarities to early communities of life on Earth. I targeted two cyanobacteria in my research, Dichothrix spp. and whatever black is, since they are believed to be important to carbon sequestration in these thrombolitic mats. The goal of my summer research project was to molecularly identify these two cyanobacteria. DNA was isolated from each organism through mat dissections and DNA extractions. I ran Polymerase Chain Reactions (PCR) to amplify the 16S ribosomal RNA (rRNA) gene in each cyanobacteria. This specific gene is found in almost all bacteria and is highly conserved, meaning any changes in the sequence are most likely due to evolution. As a result, the 16S rRNA gene can be used for bacterial identification of different species based on the sequence of their 16S rRNA gene. Since the exact sequence of the Dichothrix gene was unknown, I designed different primers that flanked the gene based on the known sequences from other taxonomically similar cyanobacteria. Once the 16S rRNA gene was amplified, I cloned the gene into specialized Escherichia coli cells and sent the gene products for sequencing. Once the sequence is obtained, it will be added to a genetic database for future reference to and classification of other Dichothrix sp.

  3. PCR-RFLP of 16S ribosomal DNA to confirm the identification of Enterococcus gallinarum and Enterococcus casseliflavus isolated from clinical and food samples PCR-RFLP do 16S DNA ribossomal para confirmar a identificação de Enterococcus gallinarum e Enterococcus casseliflavus isolados de amostras clínicas e alimentares

    Directory of Open Access Journals (Sweden)

    Aline Weber Medeiros

    2010-02-01

    Full Text Available INTRODUCTION: This study aimed to confirm the identification of Enterococcus gallinarum and Enterococcus casseliflavus isolated from clinical and food samples by PCR-RFLP. METHODS: Fifty-two strains identified by conventional biochemical exams were submitted to PCR amplification and digested with HinfI. Only 20 (38.5% of the 52 strains showed a DNA pattern expected for E. gallinarum and E. casseliflavus. RESULTS: Analysis of the results of this study showed that E. gallinarum and E. casseliflavus are occasionally erroneously identified and confirmed the potential application of 16S rDNA analysis for accurate identification of these species. CONCLUSIONS: A correct identification is important to distinguish between intrinsic and acquired vancomycin resistance.INTRODUÇÃO: O objetivo deste estudo foi confirmar a identificação de amostras clínicas e alimentos de Enterococcus gallinarum e Enterococcus casseliflavus por PCR-RFLP. MÉTODOS: Cinquenta e duas cepas identificadas por exames bioquímicos convencionais foram submetidos a amplificação por PCR e digestão com HinfI. Apenas 20 (38,5% das 52 amostras apresentaram um padrão de DNA esperado E. gallinarum e E. casseliflavus. RESULTADOS: Analise dos resultados deste estudo demonstraram que, algumas vezes E. gallinarum e E. casseliflavus são erroneamente identificados e confirmaram a potencial aplicação da análise do 16S rDNA para identificação exata destas espécies. CONCLUSÕES: A correta identificação é importante a fim de distinguir entre resistência intrínseca e adquirida à vancomicina.

  4. Binding of 16S rRNA to chloroplast 30S ribosomal proteins blotted on nitrocellulose.

    Science.gov (United States)

    Rozier, C; Mache, R

    1984-10-11

    Protein-RNA associations were studied by a method using proteins blotted on a nitrocellulose sheet. This method was assayed with Escherichia Coli 30S ribosomal components. In stringent conditions (300 mM NaCl or 20 degrees C) only 9 E. coli ribosomal proteins strongly bound to the 16S rRNA: S4, S5, S7, S9, S12, S13, S14, S19, S20. 8 of these proteins have been previously found to bind independently to the 16S rRNA. The same method was applied to determine protein-RNA interactions in spinach chloroplast 30S ribosomal subunits. A set of only 7 proteins was bound to chloroplast rRNA in stringent conditions: chloroplast S6, S10, S11, S14, S15, S17 and S22. They also bound to E. coli 16S rRNA. This set includes 4 chloroplast-synthesized proteins: S6, S11, S15 and S22. The core particles obtained after treatment by LiCl of chloroplast 30S ribosomal subunit contained 3 proteins (S6, S10 and S14) which are included in the set of 7 binding proteins. This set of proteins probably play a part in the early steps of the assembly of the chloroplast 30S ribosomal subunit.

  5. 中华蜜蜂肠道细菌群落的PCR-DGGE分析%Denaturing Gradient Gel Electrophoresis Analysis of 16S Ribosomal DNA in Apis cerana cerana Gut Bacterial Communities

    Institute of Scientific and Technical Information of China (English)

    丁进; 张国只; 苏丽娟

    2015-01-01

    肠道微生物与中华蜜蜂的生长发育密切相关,在为宿主提供营养、抵抗病原菌侵袭等方面起重要作用。为了探究中华蜜蜂在封盖一日龄蛹、破巢幼蜂和采集蜂三个重要发育阶段肠道细菌群落的结构组成及差异变化,我们对细菌16S rDNA的V6-V8可变区进行PCR-DGGE和克隆测序,并计算封盖一日龄蛹、破巣蜂和采集蜂阶段中华蜜蜂肠道菌群的多样性指数和相似性系数,结果表明:采集蜂肠道内细菌多样性指数最大,而封盖一日龄蛹和破巣幼蜂之间的肠道菌群相似性较高;测序结果初步得到了Gilliamella、Snodgrassella、Carnobacterium、Neisseriaceae、Frischella、Janthinobacterium、Pseudomonas、Lactobacillus、Lactococcus和Leuconostoc十种菌属,其中封盖一日龄蛹和破巢幼蜂的优势菌属为Snodgrassella和Pseudomonas;采集蜂的优势菌属为Gilliamella和Snodgrassella 。本研究旨在为提高中华蜜蜂的环境适应性和病虫害的防治提供依据。%Gut bacterial communities are closely related to the growth and development of Apis cerana cerana,and such communities play important roles both in the insect nutrition and colonization resistance against invasion of exotic microbes. The purpose of this study is to investigate the diversities of gut bacterial communities in different developmental stages(first instar pupa,pharate adult bee and forager bee)of A. cerana cerana and the structural differences among them. We amplified the V6-V8 region of the 16S rDNA gene of samples using universal primers and separated by DGGE. Then the separated DGGE bands were extracted,cloned and sequenced. The diversity index and similarity coefficient were calculated to reveal the constituents and dynamic changes of gut bacter ial communities in the three developmental stages of A. cerana cerana. The results showed that the microbial diversity of forager bee was significantly higher than that of first instar

  6. Expanded versions of the 16S and 23S ribosomal RNA mutation databases (16SMDBexp and 23SMDBexp)

    OpenAIRE

    Triman, K L; Peister, A; Goel, R A

    1998-01-01

    Expanded versions of the Ribosomal RNA Mutation Databases provide lists of mutated positions in 16S and 16S-like ribosomal RNA (16SMDBexp) and 23S and 23S-like ribosomal RNA (23SMDBexp) and the identity of each alteration. Alterations from organisms other than Escherichia coli are reported at positions according to the E.coli numbering system. Information provided for each mutation includes: (i) a brief description of the phenotype(s) associated with each mutation, (ii) whether a mutant pheno...

  7. Effect of mutations in the A site of 16 S rRNA on aminoglycoside antibiotic-ribosome interaction

    DEFF Research Database (Denmark)

    Recht, M I; Douthwaite, S; Dahlquist, K D;

    1999-01-01

    Decoding of genetic information occurs upon interaction of an mRNA codon-tRNA anticodon complex with the small subunit of the ribosome. The ribosomal decoding region is associated with highly conserved sequences near the 3' end of 16 S rRNA. The decoding process is perturbed by the aminoglycoside...... of universally conserved nucleotides at 1406 to 1408 and 1494 to 1495 in the decoding region of plasmid-encoded bacterial 16 S rRNA. Phenotypic changes range from the benign effect of U1406-->A or A1408-->G substitutions, to the highly deleterious 1406G and 1495 mutations that assemble into 30 S subunits...... but are defective in forming functional ribosomes. Changes in the local conformation of the decoding region caused by these mutations were identified by chemical probing of isolated 30 S subunits. Ribosomes containing 16 S rRNA with mutations at positions 1408, 1407+1494, or 1495 had reduced affinity...

  8. Molecular Approaches to Studying Microbial Communities: Targeting the 16S Ribosomal RNA Gene.

    Science.gov (United States)

    Fukuda, Kazumasa; Ogawa, Midori; Taniguchi, Hatsumi; Saito, Mitsumasa

    2016-09-01

    Culture-independent methods to detect microorganisms have been developed in parallel with traditional culture-based methods ever since the classification of bacteria based on 16S rRNA gene sequences was advocated in the 1970s. The development and the prevalence of culture-independent molecular technologies have provided revolutionary progress in microbial studies. The development of these technologies contributes significantly to the research of microorganisms that cannot be detected by traditional methods such as culture-dependent methods.Many molecular methods targeting the 16S rRNA gene, such as fluorescence in situ hybridization (FISH), quantitative PCR, terminal restriction fragment length polymorphism (T-RFLP), denaturing-gradient gel electrophoresis (DGGE), clone library analysis, and next-generation DNA sequencing (NGS) technologies, have been applied to various microbial studies. Notably, the advent of NGS technologies enabled a large-scale research of the bacterial community. Many recent studies using the NGS technologies have revealed that a larger number of bacteria and taxa than previously thought inhabit various parts of the human body and various places on the earth. The principles and characteristics of each molecular method are different, and each method possesses individual advantages; for example target specificity, comprehensiveness, rapidness, and cost efficiency. Therefore it is important that the methods used in studies are suitable for the objective and materials. Herein, we highlights molecular approaches targeting the 16S rRNA gene in bacterial community analysis, and focuses on the advantages and limitations of each technology. PMID:27627970

  9. Molecular phylogeny of silk-producing insects based on 16S ribosomal RNA and cytochrome oxidase subunit I genes

    Indian Academy of Sciences (India)

    B. Mahendran; S. K. Ghosh; S. C. Kundu

    2006-04-01

    We have examined the molecular-phylogenetic relationships between nonmulberry and mulberry silkwormspecies that belong to the families Saturniidae, Bombycidae and Lasiocampidae using 16S ribosomal RNA (16S rRNA) and cytochrome oxidase subunit I (coxI) gene sequences. Aligned nucleotide sequences of 16S rRNA and coxI from 14 silk-producing species were used for construction of phylogenetic trees by maximum likelihood and maximum parsimony methods. The tree topology on the basis of 16S rRNA supports monophyly for members of Saturniidae and Bombycidae. Weighted parsimony analysis weighted towards transversions relative to transitions (ts, tv4) for coxI resulted in more robust bootstrap support over unweighted parsimony and favours the 16S rRNA tree topology. Combined analysis reflected clear biogeographic pattern, and agrees with morphological and cytological data.

  10. Phylogenetic Relationship of Duttaphrynus melanostictus From India and China as Revealed from the Study of 12S and 16S mtDNA Genes

    OpenAIRE

    Sanjib Kr. Das; Debojyoti Dutta

    2013-01-01

    In the present study, the phylogenetic relationship of Duttaphrynus melanostictus from West Bengal, India with other members of the Bufonidiae group was undertaken using partial mitochondrial DNA (mtDNA) genes. Mitochondria were isolated from the liver of Duttaphrynus melanostictus by a non-conventional method of membrane filtration. The technique allows trapping of mitochondria on cellulose acetate membrane followed by mtDNA isolation. 12S ribosomal RNA and 16S ribosomal RNA was sequenced wi...

  11. Protocols for 16S rDNA Array Analyses of Microbial Communities by Sequence-Specific Labeling of DNA Probes

    Directory of Open Access Journals (Sweden)

    Knut Rudi

    2003-01-01

    Full Text Available Analyses of complex microbial communities are becoming increasingly important. Bottlenecks in these analyses, however, are the tools to actually describe the biodiversity. Novel protocols for DNA array-based analyses of microbial communities are presented. In these protocols, the specificity obtained by sequence-specific labeling of DNA probes is combined with the possibility of detecting several different probes simultaneously by DNA array hybridization. The gene encoding 16S ribosomal RNA was chosen as the target in these analyses. This gene contains both universally conserved regions and regions with relatively high variability. The universally conserved regions are used for PCR amplification primers, while the variable regions are used for the specific probes. Protocols are presented for DNA purification, probe construction, probe labeling, and DNA array hybridizations.

  12. 不同发酵温度下虾油中细菌的16S rDNA分子生态分析以及蛋白酶系和产品品质的变化研究%16S Ribosomal DNA-based Analysis of Bacteria in Shrimp Sauce: Effect of Fermentation Temperature on Protease System and Product Quality

    Institute of Scientific and Technical Information of China (English)

    胡小喜; 段杉; 王香君; 廖广强; 吴永和; 邝浩斌; 杨柳

    2015-01-01

    本文采用16S rDNA高通量测序技术分析了不同温度发酵下虾油菌相的变化,采用酶谱电泳研究了虾油蛋白酶系的变化,并结合测定各质量指标以探索细菌在虾油发酵中的作用.研究发现虾油中细菌数量远高于真菌数量,显示了细菌对发酵的重要贡献.虾油菌相复杂,且不同温度下菌相差异很大;发酵中菌相及蛋白酶系均呈现动态变化,25℃和35℃发酵的虾油中蛋白酶失活较少,且存在大量Tetragenococcus,Virgibacillus等产生良好风味成分的细菌;而45℃的虾油中蛋白酶失活严重,且检出的细菌与产生良好风味无关,感官评定也最差,因此,45℃不适合发酵虾油.发酵30 d时,虾油中的氨基酸态氮、无盐可溶性固形物、挥发性盐基氮(TVB-N)和三甲胺(TMA)等均达到峰值,此后各指标基本恒定,但菌相仍变化较大且有1种新蛋白酶出现,而且虾油风味继续改善.

  13. Predictive microbiology combined with metagenomic analysis targeted on the 16S rDNA : A new approach for food quality

    OpenAIRE

    Delhalle, Laurent; Ellouze, Mariem; Taminiau, Bernard; Korsak Koulagenko, Nicolas; Nezer, Carine

    2013-01-01

    OBJECTIVES The food spoilage process is mainly caused by alteration micro-organisms and classical culture-based methods have therefore been used to assess the microbiological quality of food. These techniques are simple to implement but may not be relevant to understand the modifications of the microbial ecology which occur in the food product in response to different changes in the environmental conditions. Metagenomic analysis targeted on 16S ribosomal DNA can bring about a solution to t...

  14. Asaia bogorensis peritonitis identified by 16S ribosomal RNA sequence analysis in a patient receiving peritoneal dialysis.

    Science.gov (United States)

    Snyder, Richard W; Ruhe, Jorg; Kobrin, Sidney; Wasserstein, Alan; Doline, Christa; Nachamkin, Irving; Lipschutz, Joshua H

    2004-08-01

    Here the authors report a case of refractory peritonitis leading to multiple hospitalizations and the loss of peritoneal dialysis access in a patient on automated peritoneal dialysis, caused by Asaia bogorensis, a bacterium not previously described as a human pathogen. This organism was identified by sequence analysis of the 16S ribosomal RNA gene. Unusual microbial agents may cause peritonitis, and molecular microbiological techniques are important tools for identifying these agents.

  15. Expression of gyrB and 16S ribosomal RNA genes as indicators of growth and physiological activities of Legionella pneumophila.

    Science.gov (United States)

    Okuno, Toshihiro; Tani, Katsuji; Yamaguchi, Nobuyasu; Nasu, Masao

    2015-01-01

    To determine whether the DNA gyrase (gyrB) and 16S ribosomal RNA (16S rRNA) genes can be used as indicators of the biological activities of Legionella pneumophila, the expression levels were estimated. The ratio of mRNA/DNA in gyrB was 0.7 in mid log phase and decreased drastically after the log phase. For 16S rRNA, the ratio was highest in mid log phase (7.0×10(3)), and the value that was about 10% of that in the log phase was maintained for six days. The rRNA may be vital in the resting or active but nonculturable cells that are not growing but physiologically active. The expression levels of gyrB mRNA and 16S rRNA can be used as indicators of the growth activity and the physiological activity of L. pneumophila, respectively. Therefore, by measurement of these indicators, we can evaluate the activities of Legionella cells in various environments.

  16. Identification and characterization of rhizospheric microbial diversity by 16S ribosomal RNA gene sequencing

    OpenAIRE

    Naveed, Muhammad; Mubeen, Samavia; Khan, Samiullah; Ahmed, Iftikhar; Khalid, Nauman; Suleria, Hafiz Ansar Rasul; Bano, Asghari; Mumtaz, Abdul Samad

    2014-01-01

    In the present study, samples of rhizosphere and root nodules were collected from different areas of Pakistan to isolate plant growth promoting rhizobacteria. Identification of bacterial isolates was made by 16S rRNA gene sequence analysis and taxonomical confirmation on EzTaxon Server. The identified bacterial strains were belonged to 5 genera i.e. Ensifer, Bacillus, Pseudomona, Leclercia and Rhizobium. Phylogenetic analysis inferred from 16S rRNA gene sequences showed the evolutionary relat...

  17. The structure of the archaebacterial ribosomal protein S7 and its possible interaction with 16S rRNA.

    Science.gov (United States)

    Hosaka, H; Yao, M; Kimura, M; Tanaka, I

    2001-11-01

    Ribosomal protein S7 is one of the ubiquitous components of the small subunit of the ribosome. It is a 16S rRNA-binding protein positioned close to the exit of the tRNA, and it plays a role in initiating assembly of the head of the 30S subunit. Previous structural analyses of eubacterial S7 have shown that it has a stable alpha-helix core and a flexible beta-arm. Unlike these eubacterial proteins, archaebacterial or eukaryotic S7 has an N-terminal extension of approximately 60 residues. The crystal structure of S7 from archaebacterium Pyrococcus horikoshii (PhoS7) has been determined at 2.1 A resolution. The final model of PhoS7 consists of six major alpha-helices, a short 3(10)-helix and two beta-stands. The major part (residues 18-45) of the N-terminal extension of PhoS7 reinforces the alpha-helical core by well-extended hydrophobic interactions, while the other part (residues 46-63) is not visible in the crystal and is possibly fixed only by interacting with 16S rRNA. These differences in the N-terminal extension as well as in the insertion (between alpha1 and alpha2) of the archaebacterial S7 structure from eubacterial S7 are such that they do not necessitate a major change in the structure of the currently available eubacterial 16S rRNA. Some of the inserted chains might pass through gaps formed by helices of the 16S rRNA.

  18. An intron within the 16S ribosomal RNA gene of the archaeon Pyrobaculum aerophilum

    Science.gov (United States)

    Burggraf, S.; Larsen, N.; Woese, C. R.; Stetter, K. O.

    1993-01-01

    The 16S rRNA genes of Pyrobaculum aerophilum and Pyrobaculum islandicum were amplified by the polymerase chain reaction, and the resulting products were sequenced directly. The two organisms are closely related by this measure (over 98% similar). However, they differ in that the (lone) 16S rRNA gene of Pyrobaculum aerophilum contains a 713-bp intron not seen in the corresponding gene of Pyrobaculum islandicum. To our knowledge, this is the only intron so far reported in the small subunit rRNA gene of a prokaryote. Upon excision the intron is circularized. A secondary structure model of the intron-containing rRNA suggests a splicing mechanism of the same type as that invoked for the tRNA introns of the Archaea and Eucarya and 23S rRNAs of the Archaea. The intron contains an open reading frame whose protein translation shows no certain homology with any known protein sequence.

  19. Identification and characterization of rhizospheric microbial diversity by 16S ribosomal RNA gene sequencing

    Directory of Open Access Journals (Sweden)

    Muhammad Naveed

    2014-09-01

    Full Text Available In the present study, samples of rhizosphere and root nodules were collected from different areas of Pakistan to isolate plant growth promoting rhizobacteria. Identification of bacterial isolates was made by 16S rRNA gene sequence analysis and taxonomical confirmation on EzTaxon Server. The identified bacterial strains were belonged to 5 genera i.e. Ensifer, Bacillus, Pseudomona, Leclercia and Rhizobium. Phylogenetic analysis inferred from 16S rRNA gene sequences showed the evolutionary relationship of bacterial strains with the respective genera. Based on phylogenetic analysis, some candidate novel species were also identified. The bacterial strains were also characterized for morphological, physiological, biochemical tests and glucose dehydrogenase (gdh gene that involved in the phosphate solublization using cofactor pyrroloquinolone quinone (PQQ. Seven rhizoshperic and 3 root nodulating stains are positive for gdh gene. Furthermore, this study confirms a novel association between microbes and their hosts like field grown crops, leguminous and non-leguminous plants. It was concluded that a diverse group of bacterial population exist in the rhizosphere and root nodules that might be useful in evaluating the mechanisms behind plant microbial interactions and strains QAU-63 and QAU-68 have sequence similarity of 97 and 95% which might be declared as novel after further taxonomic characterization.

  20. Sequence analysis of mitochondrial 16S ribosomal RNA gene fragment from seven mosquito species

    Indian Academy of Sciences (India)

    Yogesh S Shouche; Milind S Patole

    2000-12-01

    Mosquitoes are vectors for the transmission of many human pathogens that include viruses, nematodes and protozoa. For the understanding of their vectorial capacity, identification of disease carrying and refractory strains is essential. Recently, molecular taxonomic techniques have been utilized for this purpose. Sequence analysis of the mitochondrial 16S rRNA gene has been used for molecular taxonomy in many insects. In this paper, we have analysed a 450 bp hypervariable region of the mitochondrial 16S rRNA gene in three major genera of mosquitoes, Aedes, Anopheles and Culex. The sequence was found to be unusually A + T rich and in substitutions the rate of transversions was higher than the transition rate. A phylogenetic tree was constructed with these sequences. An interesting feature of the sequences was a stretch of Ts that distinguished between Aedes and Culex on the one hand, and Anopheles on the other. This is the first report of mitochondrial rRNA sequences from these medically important genera of mosquitoes.

  1. Identification and characterization of rhizospheric microbial diversity by 16S ribosomal RNA gene sequencing.

    Science.gov (United States)

    Naveed, Muhammad; Mubeen, Samavia; Khan, SamiUllah; Ahmed, Iftikhar; Khalid, Nauman; Suleria, Hafiz Ansar Rasul; Bano, Asghari; Mumtaz, Abdul Samad

    2014-01-01

    In the present study, samples of rhizosphere and root nodules were collected from different areas of Pakistan to isolate plant growth promoting rhizobacteria. Identification of bacterial isolates was made by 16S rRNA gene sequence analysis and taxonomical confirmation on EzTaxon Server. The identified bacterial strains were belonged to 5 genera i.e. Ensifer, Bacillus, Pseudomona, Leclercia and Rhizobium. Phylogenetic analysis inferred from 16S rRNA gene sequences showed the evolutionary relationship of bacterial strains with the respective genera. Based on phylogenetic analysis, some candidate novel species were also identified. The bacterial strains were also characterized for morphological, physiological, biochemical tests and glucose dehydrogenase (gdh) gene that involved in the phosphate solublization using cofactor pyrroloquinolone quinone (PQQ). Seven rhizoshperic and 3 root nodulating stains are positive for gdh gene. Furthermore, this study confirms a novel association between microbes and their hosts like field grown crops, leguminous and non-leguminous plants. It was concluded that a diverse group of bacterial population exist in the rhizosphere and root nodules that might be useful in evaluating the mechanisms behind plant microbial interactions and strains QAU-63 and QAU-68 have sequence similarity of 97 and 95% which might be declared as novel after further taxonomic characterization. PMID:25477935

  2. Studies on the ability of partially iodinated 16S RNA to participate in 30S ribosome assembly.

    Science.gov (United States)

    Schendel, P L; Craven, G R

    1976-11-01

    Deproteinated 16S RNA was iodinated at pH 5.0 in an aqueous solution containing TlCl3 plus KI for 1-5 hours at 42 degrees C. Under these conditions 33 moles of iodine are incorporated per mole of RNA. As judged by sucrose gradient sedimentation, the iodinated RNA does not exhibit any large alteration in conformation as compared to unmodified 16S. The iodinated RNA was examined for its ability to reconstitute with total 30S proteins. Sedimentation velocity analysis reveals that the reconstituted subunit has a sedimentation constant of approximately 20S. In addition, protein analysis of particles reconstituted with 16S RNA iodinated for 5 hours indicates that proteins S2, S10, S13, S14, S15, S17, S18, S19, and S21 are no longer able to participate in the 30S assembly process and that proteins S6, S16 and S20 are present in reduced amounts. The ramifications of these results concerning protein-RNA and RNA-RNA interactions occurring in ribosome assembly are discussed.

  3. Molecular Diagnosis of Periprosthetic Joint Infection by Quantitative RT-PCR of Bacterial 16S Ribosomal RNA

    Directory of Open Access Journals (Sweden)

    Mel S. Lee

    2013-01-01

    Full Text Available The diagnosis of periprosthetic joint infection is sometimes straightforward with purulent discharge from the fistula tract communicating to the joint prosthesis. However it is often difficult to differentiate septic from aseptic loosening of prosthesis because of the high culture-negative rates in conventional microbiologic culture. This study used quantitative reverse transcription polymerase chain reaction (RT-qPCR to amplify bacterial 16S ribosomal RNA in vitro and in 11 clinical samples. The in vitro analysis demonstrated that the RT-qPCR method was highly sensitive with the detection limit of bacterial 16S rRNA being 0.148 pg/μl. Clinical specimens were analyzed using the same protocol. The RT-qPCR was positive for bacterial detection in 8 culture-positive cases (including aerobic, anaerobic, and mycobacteria and 2 culture-negative cases. It was negative in one case that the final diagnosis was confirmed without infection. The molecular diagnosis of bacterial infection using RT-qPCR to detect bacterial 16S rRNA around a prosthesis correlated well with the clinical findings. Based on the promising clinical results, we were attempting to differentiate bacterial species or drug-resistant strains by using species-specific primers and to detect the persistence of bacteria during the interim period before the second stage reimplantation in a larger scale of clinical subjects.

  4. Ribosomal protein S7 from Escherichia coli uses the same determinants to bind 16S ribosomal RNA and its messenger RNA.

    Science.gov (United States)

    Robert, F; Brakier-Gingras, L

    2001-02-01

    Ribosomal protein S7 from Escherichia coli binds to the lower half of the 3' major domain of 16S rRNA and initiates its folding. It also binds to its own mRNA, the str mRNA, and represses its translation. Using filter binding assays, we show in this study that the same mutations that interfere with S7 binding to 16S rRNA also weaken its affinity for its mRNA. This suggests that the same protein regions are responsible for mRNA and rRNA binding affinities, and that S7 recognizes identical sequence elements within the two RNA targets, although they have dissimilar secondary structures. Overexpression of S7 is known to inhibit bacterial growth. This phenotypic growth defect was relieved in cells overexpressing S7 mutants that bind poorly the str mRNA, confirming that growth impairment is controlled by the binding of S7 to its mRNA. Interestingly, a mutant with a short deletion at the C-terminus of S7 was more detrimental to cell growth than wild-type S7. This suggests that the C-terminal portion of S7 plays an important role in ribosome function, which is perturbed by the deletion.

  5. Algae-bacteria association inferred by 16S rDNA similarity in established microalgae cultures.

    Science.gov (United States)

    Schwenk, Dagmar; Nohynek, Liisa; Rischer, Heiko

    2014-06-01

    Forty cultivable, visually distinct bacterial cultures were isolated from four Baltic microalgal cultures Chlorella pyrenoidosa, Scenedesmus obliquus, Isochrysis sp., and Nitzschia microcephala, which have been maintained for several years in the laboratory. Bacterial isolates were characterized with respect to morphology, antibiotic susceptibility, and 16S ribosomal DNA sequence. A total of 17 unique bacterial strains, almost all belonging to one of three families, Rhodobacteraceae, Rhizobiaceae, and Erythrobacteraceae, were subsequently isolated. The majority of isolated bacteria belong to Rhodobacteraceae. Literature review revealed that close relatives of the bacteria isolated in this study are not only often found in marine environments associated with algae, but also in lakes, sediments, and soil. Some of them had been shown to interact with organisms in their surroundings. A Basic Local Alignment Search Tool study indicated that especially bacteria isolated from the Isochrysis sp. culture were highly similar to microalgae-associated bacteria. Two of those isolates, I1 and I6, belong to the Cytophaga-Flavobacterium-Bacteroides phylum, members of which are known to occur in close communities with microalgae. An UniFrac analysis revealed that the bacterial community of Isochrysis sp. significantly differs from the other three communities.

  6. Genetic variability of Echinococcus granulosus based on the mitochondrial 16S ribosomal RNA gene.

    Science.gov (United States)

    Wang, Ning; Wang, Jiahai; Hu, Dandan; Zhong, Xiuqin; Jiang, Zhongrong; Yang, Aiguo; Deng, Shijin; Guo, Li; Tsering, Dawa; Wang, Shuxian; Gu, Xiaobin; Peng, Xuerong; Yang, Guangyou

    2015-06-01

    Echinococcus granulosus is the etiological agent of cystic echinococcosis, a major zoonotic disease of both humans and animals. In this study, we assessed genetic variability and genetic structure of E. granulosus in the Tibet plateau, using the complete mitochondrial 16 S ribosomal RNA gene for the first time. We collected and sequenced 62 isolates of E. granulosus from 3 populations in the Tibet plateau. A BLAST analysis indicated that 61 isolates belonged to E. granulosus sensu stricto (genotypes G1-G3), while one isolate belonged to E. canadensis (genotype G6). We detected 16 haplotypes with a haplotype network revealing a star-like expansion, with the most common haplotype occupying the center of the network. Haplotype diversity and nucleotide diversity were low, while negative values were observed for Tajima's D and Fu's Fs. AMOVA results and Fst values revealed that the three geographic populations were not genetically differentiated. Our results suggest that a population bottleneck or population expansion has occurred in the past, and that this explains the low genetic variability of E. granulosus in the Tibet Plateau.

  7. A ribonucleoprotein fragment of the 30 S ribosome of E. coli containing two contiguous domains of the 16 S RNA.

    Science.gov (United States)

    Spitnik-Elson, P; Elson, D; Avital, S; Abramowitz, R

    1982-08-11

    Ribonucleoprotein fragments of the 30 S ribosome of E. coli have been prepared by limited ribonuclease digestion and mild heating of the ribosome in a constant ionic environment. One such fragment has been described previously. A second electrophoretically homogeneous fragment has now been isolated and its RNA and protein moieties have been characterized. It contains the 5' half of the 16 S RNA, encompassing domains I and II except for the extreme 5' terminus and several small gaps. Seven proteins are present: S4, S5, S6, S8, S12, S15 and S20. The RNA binding sites of five of these proteins are known, and all are RNA sequences that are present in the fragment. Published neutron scattering and immuno-electron microscopic data indicate that six of the proteins are clustered together in a cross sectional slice through the center of the subunit. After deproteinization, the RNA moiety gives two bands in gel electrophoresis, one containing domains I and II and the other, essentially only domain II. The former, although larger, migrates faster in gel electrophoresis, indicating that RNA domains I and II interact with each other in such a way as to become more compact than domain II by itself.

  8. Native Valve Endocarditis due to Corynebacterium striatum confirmed by 16S Ribosomal RNA Sequencing: A Case Report and Literature Review

    Science.gov (United States)

    2016-01-01

    Corynebacterium species are non-fermentous Gram-positive bacilli that are normal flora of human skin and mucous membranes and are commonly isolated in clinical specimens. Non-diphtheriae Corynebacterium are regarded as contaminants when found in blood culture. Currently, Corynebacterium striatum is considered one of the emerging nosocomial agents implicated in endocarditis and serious infections. We report a case of native-valve infective endocarditis caused by C. striatum, which was misidentified by automated identification system but identified accurately by 16S ribosomal RNA sequencing, in a 55-year-old male patient. The patient had two mobile vegetations on his mitral valve, both of which had high embolic risk. Through surgical valve replacement and an antibiotic regimen, the patient recovered completely. In unusual clinical scenarios, C. striatum should not be simply dismissed as a contaminant when isolated from clinical specimens. The possibility of C. striatum infection should be considered even in an immunocompetent patient, and we suggest a genotypic assay, such as 16S rRNA sequencing, to confirm species identity. PMID:27659439

  9. In vitro synthesis of ribosomal proteins directed by Escherichia coli DNA.

    Science.gov (United States)

    Kaltschmidt, E; Kahan, L; Nomura, M

    1974-02-01

    In vitro synthesis of a number of E. coli 30S ribosomal proteins has been demonstrated in a cell-free system consisting of ribosomes, initiation factors, RNA polymerase, a fraction containing soluble enzymes and factors, and E. coli DNA. DNA-dependent synthesis of the following 30S proteins has been demonstrated: S4, S5, S7, S8, S9, S10, S13, S14, S16, S19, and S20.

  10. Comparative performance of the 16S rRNA gene in DNA barcoding of amphibians

    Directory of Open Access Journals (Sweden)

    Chiari Ylenia

    2005-03-01

    Full Text Available Abstract Background Identifying species of organisms by short sequences of DNA has been in the center of ongoing discussions under the terms DNA barcoding or DNA taxonomy. A C-terminal fragment of the mitochondrial gene for cytochrome oxidase subunit I (COI has been proposed as universal marker for this purpose among animals. Results Herein we present experimental evidence that the mitochondrial 16S rRNA gene fulfills the requirements for a universal DNA barcoding marker in amphibians. In terms of universality of priming sites and identification of major vertebrate clades the studied 16S fragment is superior to COI. Amplification success was 100% for 16S in a subset of fresh and well-preserved samples of Madagascan frogs, while various combination of COI primers had lower success rates.COI priming sites showed high variability among amphibians both at the level of groups and closely related species, whereas 16S priming sites were highly conserved among vertebrates. Interspecific pairwise 16S divergences in a test group of Madagascan frogs were at a level suitable for assignment of larval stages to species (1–17%, with low degrees of pairwise haplotype divergence within populations (0–1%. Conclusion We strongly advocate the use of 16S rRNA as standard DNA barcoding marker for vertebrates to complement COI, especially if samples a priori could belong to various phylogenetically distant taxa and false negatives would constitute a major problem.

  11. Toxicity analysis of pesticides on cyanobacterial species by 16S rDNA molecular characterization

    Directory of Open Access Journals (Sweden)

    J. I. Nirmal Kumar

    2013-06-01

    Full Text Available Damaging effects of endosulfan on native structure of DNA, evident as a result of PCR based assay such as 16S rDNA amplification and sequencing, led to formation of gaps, mismatching of base pairs and dissimilarities in entire 16S rDNA sequences of treated cultures. Endosulfan was the most fatal to Westiellopsis prolifica of 16S rDNA region at 40ppm insecticide induced series of mispairing, and other lesions amounting up to 20% dissimilarity and 7% gaps. Whereas, 16S rDNA region of Anabaena fertilissima was comparatively less influenced with 18% dissimilarity and 7% gaps in response to 12ppm endosulfan, while 16S rDNA gene of Aulosira fertilissima was the least prone to changes with 17% dissimilarity, and 5% gaps under 60ppm endosulfan stress by the end of 16 days. On the other side, impact of fungicide tebuconazole after 16 days reflected identities up to 78% and 8% gaps for 30ppm treated A. fertilissima, while 60ppm treatment instilled 79% similarities with 10% gaps in W. prolifica and 83% identities with 5% gaps of Aulosira fertilissima after 16 days.

  12. Identification of Novel RNA-Protein Contact in Complex of Ribosomal Protein S7 and 3'-Terminal Fragment of 16S rRNA in E. coli.

    Science.gov (United States)

    Golovin, A V; Khayrullina, G A; Kraal, B; Kopylov, Capital A Cyrillic М

    2012-10-01

    For prokaryotes in vitro, 16S rRNA and 20 ribosomal proteins are capable of hierarchical self- assembly yielding a 30S ribosomal subunit. The self-assembly is initiated by interactions between 16S rRNA and three key ribosomal proteins: S4, S8, and S7. These proteins also have a regulatory function in the translation of their polycistronic operons recognizing a specific region of mRNA. Therefore, studying the RNA-protein interactions within binary complexes is obligatory for understanding ribosome biogenesis. The non-conventional RNA-protein contact within the binary complex of recombinant ribosomal protein S7 and its 16S rRNA binding site (236 nucleotides) was identified. UV-induced RNA-protein cross-links revealed that S7 cross-links to nucleotide U1321 of 16S rRNA. The careful consideration of the published RNA- protein cross-links for protein S7 within the 30S subunit and their correlation with the X-ray data for the 30S subunit have been performed. The RNA - protein cross-link within the binary complex identified in this study is not the same as the previously found cross-links for a subunit both in a solution, and in acrystal. The structure of the binary RNA-protein complex formed at the initial steps of self-assembly of the small subunit appears to be rearranged during the formation of the final structure of the subunit.

  13. Genetic Analysis of the Invariant Residue G791 in Escherichia coli 16S rRNA Implicates RelA in Ribosome Function▿

    OpenAIRE

    Kim, Hong-Man; Ryou, Sang-Mi; Song, Woo-Seok; Sim, Se-Hoon; Cha, Chang-Jun; Han, Seung Hyun; Ha, Nam-Chul; Kim, Jae-Hong; BAE, Jeehyeon; Cunningham, Philip R.; Lee, Kangseok

    2009-01-01

    Previous studies identified G791 in Escherichia coli 16S rRNA as an invariant residue for ribosome function. In order to establish the functional role of this residue in protein synthesis, we searched for multicopy suppressors of the mutant ribosomes that bear a G-to-U substitution at position 791. We identified relA, a gene whose product has been known to interact with ribosomes and trigger a stringent response. Overexpression of RelA resulted in the synthesis of approximately 1.5 times more...

  14. Analysis of 16S rRNA gene sequences and circulating cell-free DNA from plasma of chronic fatigue syndrome and non-fatigued subjects

    Directory of Open Access Journals (Sweden)

    Unger Elizabeth R

    2002-12-01

    Full Text Available Abstract Background The association of an infectious agent with chronic fatigue syndrome (CFS has been difficult and is further complicated by the lack of a known lesion or diseased tissue. Cell-free plasma DNA could serve as a sentinel of infection and disease occurring throughout the body. This type of systemic sample coupled with broad-range amplification of bacterial sequences was used to determine whether a bacterial pathogen was associated with CFS. Plasma DNA from 34 CFS and 55 non-fatigued subjects was assessed to determine plasma DNA concentration and the presence of bacterial 16S ribosomal DNA (rDNA sequences. Results DNA was isolated from 81 (91% of 89 plasma samples. The 55 non-fatigued subjects had higher plasma DNA concentrations than those with CFS (average 151 versus 91 ng and more CFS subjects (6/34, 18% had no detectable plasma DNA than non-fatigued subjects (2/55, 4%, but these differences were not significant. Bacterial sequences were detected in 23 (26% of 89. Only 4 (14% CFS subjects had 16S rDNA sequences amplified from plasma compared with 17 (32% of the non-fatigued (P = 0.03. All but 1 of the 23 16S rDNA amplicon-positive subjects had five or more unique sequences present. Conclusions CFS subjects had slightly lower concentrations or no detectable plasma DNA than non-fatigued subjects. There was a diverse array of 16S rDNA sequences in plasma DNA from both CFS and non-fatigued subjects. There were no unique, previously uncharacterized or predominant 16S rDNA sequences in either CFS or non-fatigued subjects.

  15. Genetic analysis on 16S rDNA of brucella%布鲁菌16S rDNA基因遗传分析

    Institute of Scientific and Technical Information of China (English)

    李克诚; 周邦谣; 夏菲

    2013-01-01

    目的 通过分析临床分离的布鲁菌、其他盐杆菌科细菌以及临床常见致病菌的16S rDNA基因片段的差异并构建16S rDNA系统发育树,为进一步研究布鲁菌打下基础.方法 PCR扩增临床分离株的16SrDNA并测序;从EMBL下载常见盐杆菌科细菌和临床上常见致病菌的16S rDNA序列.利用CLUSTALX和MEGA程序进行16S rDNA比对并构建系统发育树.结果 成功扩增了临床分离菌株的16S rDNA,得到测序结果,比对临床分离菌株和相关菌株后,发现了特异序列5’-ATCCCGGTCGCGGTTAGTGG-3';系统发育树表明不同种的布鲁菌间的距离非常接近;布鲁菌和醋菌属的进化距离较近,但是和其他的盐杆菌的进化距离较远.结论 在布鲁菌16S rDNA中存在特异序列5'-ATCCCGGTCGCGGTTAGTGG-3’,有可能作为探针来快速检测布鲁氏菌.%Objective To analyze and to compare the genetic characteristics of 16S rDNA gene of Brucella with other halobacteriaceae and pathogenic bacteria, and to construct phylogenetic tree to find the specific sequence. Methods 16s rDNA of Brucella isolated from clinical sample was amplified and sequenced, which was then compared with sequences of halobacteriaceae and other pathogenic bacteria downloaded from EM-BL. CLUSTALA and MEGA software were used for the comparison of the sequences and building of the phylogenetic tree. Results 16s rDNA was successfully amplified and sequenced. Meanwhile, a specific sequence of 5' -ATCCCGGTCGCGGTTAGTGG-3' was identified. Phylogenetic tree showed that the distance was very close among different species of Brucella and was also closer to acetobacter sp. . but was farther to other halobacteriaceae. Conclusions A specific sequence is present in 16S rDNA of brucella which could be used as a probe to detect Brucella.

  16. 16S ribosomal RNA-based methods to monitor changes in the hindgut bacterial community of piglets after oral administration of Lactobacillus sobrius S1

    NARCIS (Netherlands)

    Su, Y.; Yao, W.; Perez-Gutierrez, O.N.; Smidt, H.; Zhu, W.Y.

    2008-01-01

    16S ribosomal RNA (rRNA) gene based PCR/denaturing gradient gel electrophoresis (DGGE) and real-time PCR were used to monitor the changes in the composition of microbiota in the hindgut of piglets after oral administration of Lactobacillus sobrius S1. Six litters of neonatal piglets were divided ran

  17. 16s rRNA的保守字和进化树重建%Conserved Words in 16s Ribosomal RNA Deduced from Evolutionary Tree Reconstruction

    Institute of Scientific and Technical Information of China (English)

    罗辽复; 贾孟文

    2002-01-01

    Evolutionary distance is defined by oligonucleotide (n-bases) frequency difference of two sequences.Phylogenetic tree is reconstructed using a set of 16S (18S) rRNA sequences and the definition of distance.The quality of trees generally improves with increasing n and reaches a plateau of best fit at n=7 or 8.So,the 7-mer or 8-mer frequencies provides a basis to describe rRNA evolution.Then,a group of 7-mers are deduced which are correlate well with evolution.Evolution-related conservative words longer than 7 bases for Bacteria and Archaea in 16S rRNA sequences have been found.They are highly conserved in nearly all species of a kingdom (or a sub-kingdom) and are located on nearly same sites of sequences. The structural meaning of these conservative words is discussed briefly.%据寡核苷(n核苷)频数差定义进化距离,由此构成16s rRNA进化树,当n=7,8时和实验资料符合很好,在寻找出全部进化相关的7-核苷的基础上,本文进一步求得了长度大于7的保守字,它们在一个界别中的诸物种中高度保守,并出现于核糖体序列的基本相同的位置上,这些保守字对于核糖体的早期进化至关重要.

  18. The use of 16S and 16S-23S rDNA to easily detect and differentiate common Gram-negative orchard epiphytes.

    Science.gov (United States)

    Jeng, R S; Svircev, A M; Myers, A L; Beliaeva, L; Hunter, D M; Hubbes, M

    2001-02-01

    The identification of Gram-negative pathogenic and non-pathogenic bacteria commonly isolated from an orchard phylloplane may result in a time consuming and tedious process for the plant pathologist. The paper provides a simple "one-step" protocol that uses the polymerase chain reaction (PCR) to amplify intergenic spacer regions between 16S and 23S genes and a portion of 16S gene in the prokaryotic rRNA genetic loci. Amplified 16S rDNA, and restriction fragment length polymorphisms (RFLP) following EcoRI digestion produced band patterns that readily distinguished between the plant pathogen Erwinia amylovora (causal agent of fire blight in pear and apple) and the orchard epiphyte Pantoea agglomerans (formerly E. herbicola). The amplified DNA patterns of 16S-23S spacer regions may be used to differentiate E. amylovora at the intraspecies level. Isolates of E. amylovora obtained from raspberries exhibited two major fragments while those obtained from apples showed three distinct amplified DNA bands. In addition, the size of the 16S-23S spacer region differs between Pseudomonas syringae and Pseudomonas fluorescens. The RFLP pattern generated by HaeIII digestion may be used to provide a rapid and accurate identification of these two common orchard epiphytes. PMID:11166101

  19. Photoinduced cross-linkage, in situ, of Escherichia coli 30S ribosomal proteins to 16S rRNA: identification of cross-linked proteins and relationships between reactivity and ribosome structure.

    Science.gov (United States)

    Gorelic, L

    1976-08-10

    The kinetics of photoinduced cross-linkage of Escherichia coli 30S ribosomal proteins to the 16S-rRNA molecule in the intact Escherichia coli 30S ribosomal subunit was studied in this report. All of the 30S ribosomal proteins become cross-linked to the 16S rRNA before changes in the sedimentation characteristics of the 30S ribosomal subunit can be detected. The proteins exhibit different reactivities in the cross-linkage reaction. One group of proteins-S3, S7-S9, S11, S12, and S15-S19-is cross-linked to the 16S rRNA by single-hit kinetics, or by photoprocesses of nonunity but low multiplicities. A second group of proteins--S1, S2, S4-S6, S10, S13, S14, and S21--is cross-linked to the 16S rRNA by photoprocesses of a complex nature. A comparison of these data with other properties of the individual 30S ribosomal proteins related to ribosome structure indicated that most of the 30S ribosomal proteins cross-linked to the 16S rRNA by photoprocesses of low multiplicities had been classified rRNA-binding proteins by nonphotochemical methods, and most of the proteins cross-linked to the 16S rRNA by photoprocesses of large multiplicities had been classified as nonbinding proteins. There were certain exceptions to these correlations. Proteins S4 and S20, both RNA-binding proteins, become cross-linked to the 16S rRNA by photoprocessses of large multiplicities, and proteins S3, S11, S12, and S18, none of which have been classified RNA-binding proteins, exhibited low multiplicities in the cross-linkage reaction. All of these exceptions could be explained in terms of limitations inherent in the photochemical methods used in this study and in other types of methods that have been used to study RNA-protein interactions in the 30S ribosomal subunit. The data presented here also suggest that labile RNA-protein cross-links are present in the uv-irradiated 30S ribosomal subunits, and that neither peptide-bond cleavage nor photoinduced modification of the charged side-chain groups in

  20. Phylogenetic Relationship of Duttaphrynus melanostictus From India and China as Revealed from the Study of 12S and 16S mtDNA Genes

    Directory of Open Access Journals (Sweden)

    Sanjib Kr. Das

    2013-01-01

    Full Text Available In the present study, the phylogenetic relationship of Duttaphrynus melanostictus from West Bengal, India with other members of the Bufonidiae group was undertaken using partial mitochondrial DNA (mtDNA genes. Mitochondria were isolated from the liver of Duttaphrynus melanostictus by a non-conventional method of membrane filtration. The technique allows trapping of mitochondria on cellulose acetate membrane followed by mtDNA isolation. 12S ribosomal RNA and 16S ribosomal RNA was sequenced with primers designed in our laboratory. mtDNA sequence from 18 different Bufo sp. found across the world were used for the phylogenetic analysis. Results were interpreted from the transition/transversion of nucleotides, genetic distance and maximum parsimony analysis. The findings indicates that D. melanostictus is very closely related to the Bufo melanostictus of China. The possible reasons of such close similarity between two distantly residing species (D. melanostictus of India and Bufo melanostictus of China have been discussed.

  1. 16S rRNA is a better choice than COI for DNA barcoding hydrozoans in the coastal waters of China

    Institute of Scientific and Technical Information of China (English)

    ZHENG Lianming; HE Jinru; LIN Yuanshao; CAO Wenqing; ZHANG Wenjing

    2014-01-01

    Identification of hydrozoan species is challenging, even for taxonomic experts, due to the scarcity of distinct morphological characters and phenotypic plasticity. DNA barcoding provides an efficient method for spe-cies identification, however, the choice between mitochondrial cytochrome c oxidase subunit I (COI) and large subunit ribosomal RNA gene (16S) as a standard barcode for hydrozoans is subject to debate. Herein, we directly compared the barcode potential of COI and 16S in hydrozoans using 339 sequences from 47 pelagic hydrozoan species. Analysis of Kimura 2-parameter genetic distances (K2P) documented the mean intraspecific/interspecific variation for COI and 16S to be 0.004/0.204 and 0.003/0.223, respectively. An obvi-ous“barcoding gap”was detected for all species in both markers and all individuals of a species clustered together in both the COI and 16S trees. These results suggested that the species within the studied taxa can be efficiently and accurately identified by COI and 16S. Furthermore, our results confirmed that 16S was a better phylogenetic marker for hydrozoans at the genus level, and in some cases at the family level. Con-sidering the resolution and effectiveness for barcoding and phylogenetic analyses of Hydrozoa, we strongly recommend 16S as the standard barcode for hydrozoans.

  2. The Structure of Aquifex aeolicus Ribosomal Protein S8 Reveals a Unique Subdomain That Contributes to Extremely-Tight Association With 16S rRNA

    OpenAIRE

    Menichelli, Elena; Edgcomb, Stephen P.; Recht, Michael I.; Williamson, James R.

    2011-01-01

    The assembly of ribonucleoprotein complexes occurs in a broad range of conditions, but the principles that promote assembly and allow function at high temperature are poorly understood. The ribosomal protein S8 from the hyperthemophilic bacterium Aquifex aeolicus (AS8) is unique in that there is a 41 residue insertion in the consensus S8 sequence. In addition, AS8 exhibits an unusually-high affinity for the 16S ribosomal RNA (rRNA), characterized by a picomolar dissociation constant that is a...

  3. Interconversion of active and inactive 30 S ribosomal subunits is accompanied by a conformational change in the decoding region of 16 S rRNA

    DEFF Research Database (Denmark)

    Moazed, D; Van Stolk, B J; Douthwaite, S;

    1986-01-01

    Zamir, Elson and their co-workers have shown that 30 S ribosomal subunits are reversibly inactivated by depletion of monovalent or divalent cations. We have re-investigated the conformation of 16 S rRNA in the active and inactive forms of the 30 S subunit, using a strategy that is designed......' regions of 16 S rRNA. The inactive form also shows significantly decreased reactivity at positions 1533 to 1538 (the Shine-Dalgarno region), in agreement with earlier findings. The principal changes in reactivity involve the universally conserved nucleotides G926, C1395, A1398 and G1401. The three purines...

  4. 蜡状芽胞杆菌群16S rDNA分析%Analysis of 16S rDNA in the Bacillus cereus Group

    Institute of Scientific and Technical Information of China (English)

    邹寰; 喻子牛; 孙明

    2008-01-01

    蜡状芽胞杆菌群主要包括炭疽芽胞杆菌(Bacillus anthracis)、蜡状芽胞杆菌(Bacillus cereus)、苏云金芽胞杆菌(Bacillus thuringiensis).GenBank已有这个群的8个菌株完成了全基因组序列测定.对这8株蜡状芽胞杆菌群菌株中98条16S rDNA的序列进行相互BLAST比较,发现在同一基因组内各个16S rDNA拷贝全局相似度最低为96.47%,在不同基因组间16S rDNA局部片段比对最小相似度达到99.72%,对应片段长度也有1417 bp.这点充分说明,该群的细菌完全共用同一种16S rDNA,根据16S rDNA给细菌分类的特点,它们应该属于同一个种.在亲缘关系上,枯草芽胞杆菌离蜡状芽胞杆菌群最近.

  5. Mutation detection analysis of a region of 16S-like ribosomal RNA gene of Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii

    OpenAIRE

    Khairnar Krishna; Parija Subhash

    2008-01-01

    Abstract Background The level of intra-species genetic variation in Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii populations in a localized geographic area, like Puducherry, India, remains unknown. Methods In the present study the existence of genetic variation in the nested multiplex polymerase chain reaction (NM-PCR) amplified region of the 16S-like ribosomal RNA genes of E. histolytica, E. dispar and E. moshkovskii was investigated by riboprinting and single strand con...

  6. Genomic and Haplotype Comparison of Butanol Producing Bacteria Based on 16S rDNA

    OpenAIRE

    Ekwan Nofa Wiratno; Suharjono; Agustin Krisna Wardani

    2016-01-01

    High butanol demand for transportation fuel triggers butanol production development. Exploration of butanolproducing bacteria using genomic comparison and biogeography will help to develop butanol industry. The objectives of this research were butanol production, genome comparison and haplotype analysis of butanolproducing bacteria from Ranu Pani Lake sediment using 16S rDNA sequences. The highest butanol concentrations were showed by Paenibacillus polymyxa RP 2.2 isolate (10.34 g...

  7. Distinct Genetic Lineages of Bactrocera caudata (Insecta: Tephritidae) Revealed by COI and 16S DNA Sequences

    OpenAIRE

    Phaik-Eem Lim; Ji Tan; I WAYAN SUANA; Praphathip Eamsobhana; Hoi Sen Yong

    2012-01-01

    The fruit fly Bactrocera caudata is a pest species of economic importance in Asia. Its larvae feed on the flowers of Cucurbitaceae such as Cucurbita moschata. To-date it is distinguished from related species based on morphological characters. Specimens of B. caudata from Peninsular Malaysia and Indonesia (Bali and Lombok) were analysed using the partial DNA sequences of cytochrome c oxidase subunit I (COI) and 16S rRNA genes. Both gene sequences revealed that B. caudata from Peninsular Malays...

  8. Evidence that E. coli ribosomal protein S13 has two separable functional domains involved in 16S RNA recognition and protein S19 binding.

    Science.gov (United States)

    Schwarzbauer, J; Craven, G R

    1985-09-25

    We have found that E. coli ribosomal protein S13 recognizes multiple sites on 16S RNA. However, when protein S19 is included with a mixture of proteins S4, S7, S8, S16/S17 and S20, the S13 binds to the complex with measurably greater strength and with a stoichiometry of 1.5 copies per particle. This suggests that the protein may have two functional domains. We have tested this idea by cleaving the protein into two polypeptides. It was found that one of the fragments, composed of amino acid residues 84-117, retained the capacity to bind 16S RNA at multiple sites. Protein S19 had no affect on the strength or stoichiometry of the binding of this fragment. These data suggest that S13 has a C-terminal domain primarily responsible for RNA recognition and possibly that the N-terminal region is important for association with protein S19.

  9. Interaction of ribosomal proteins S5, S6, S11, S12, S18 and S21 with 16 S rRNA.

    Science.gov (United States)

    Stern, S; Powers, T; Changchien, L M; Noller, H F

    1988-06-20

    We have examined the effects of assembly of ribosomal proteins S5, S6, S11, S12, S18 and S21 on the reactivities of residues in 16 S rRNA towards chemical probes. The results show that S6, S18 and S11 interact with the 690-720 and 790 loop regions of 16 S rRNA in a highly co-operative manner, that is consistent with the previously defined assembly map relationships among these proteins. The results also indicate that these proteins, one of which (S18) has previously been implicated as a component of the ribosomal P-site, interact with residues near some of the recently defined P-site (class II tRNA protection) nucleotides in 16 S rRNA. In addition, assembly of protein S12 has been found to result in the protection of residues in both the 530 stem/loop and the 900 stem regions; the latter group is closely juxtaposed to a segment of 16 S rRNA recently shown to be protected from chemical probes by streptomycin. Interestingly, both S5 and S12 appear to protect, to differing degrees, a well-defined set of residues in the 900 stem/loop and 5'-terminal regions. These observations are discussed in terms of the effects of S5 and S12 on streptomycin binding, and in terms of the class III tRNA protection found in the 900 stem of 16 S rRNA. Altogether these results show that many of the small subunit proteins, which have previously been shown to be functionally important, appear to be associated with functionally implicated segments of 16 S rRNA.

  10. Genomic and Haplotype Comparison of Butanol Producing Bacteria Based on 16S rDNA

    Directory of Open Access Journals (Sweden)

    Ekwan Nofa Wiratno

    2016-04-01

    Full Text Available High butanol demand for transportation fuel triggers butanol production development. Exploration of butanolproducing bacteria using genomic comparison and biogeography will help to develop butanol industry. The objectives of this research were butanol production, genome comparison and haplotype analysis of butanolproducing bacteria from Ranu Pani Lake sediment using 16S rDNA sequences. The highest butanol concentrations were showed by Paenibacillus polymyxa RP 2.2 isolate (10.34 g.L-1, followed by Bacillus methylotrophicus RP 3.2 and B. methylotrophicus RP 7.2 isolate (10.11 g.L-1 and 9.63 g.L-1 respectively. Paenibacillus polymyxa RP 2.2 showed similarity in nucleotide composition (ATGC with B. methylotrophicus RP 3.2, B. methylotrophicus RP 7.2, P. polymyxa CR1, Bacillus amyloliquefaciens NELB-12, and Paenibacillus polymyxa WR-2. Clostridium acetobutylicum ATCC 824 showed similarity in nucleotide composition (ATGC with Clostridium saccharoperbutylacetonicum N1-4, and Clostridium saccharobutylicum Ox29. The lowest G+C content was C. saccharobutylicum Ox29 (51.35%, and the highest was B. methylotrophicus RP 7.2 (55.33%. Conserved region of 16S rDNA (1044 bp were consisted of 17 conserved sequences. The number of Parsimony Informative Site (PIS was 319 spot and single tone was 48 spot. We found in this study that all of butanolproducing bacterial DNA sequences have clustered to 8 haplotypes. Based on the origin of sample, there were three haplotype groups. Bacteria from group A were could produce butanol 8.9-10.34 g.L-1, group B 9.2-14.2 g.L-1 and group C was could produce butanol 0.47 g.L-1. The haplotype analysis of bacteria based on 16S rDNA sequences in this study could predict capability of butanol production.

  11. Effect of single base changes and the absence of modified bases in 16S RNA on the reconstitution and function of Escherichia coli 30S ribosomes

    International Nuclear Information System (INIS)

    The gene coding for E. coli 16S rRNA was placed in pUC19 under the control of the strong class III T7 promoter, phi 10, by ligation of the 1490 bp BclI/BstEII fragment of the rrnB operon with appropriate synthetic oligodeoxynucleotides. Such constructs allowed efficient in vitro synthesis of full-length transcripts (up to 900 mol RNA/mol template) free of modified bases. The synthetic RNA could be assembled into 30S subunits upon addition of E. coli 30S ribosomal proteins. The particles co-sedimented with authentic 30S particles and were electron microscopically indistinguishable from them. Upon addition of 50S subunits, codon-dependent P-site binding of tRNA and codon-dependent polypeptide synthesis were >80% of 30S reconstituted from natural 16S RNA and >50% of isolated 30S. UV-induced crosslinking of P-site bound AcVal-tRNA to residue C1400 was preserved. Changing C1400 to A had little effect on reconstitution, P-site binding, or polypeptide synthesis. However, the substitution of C1499 by G markedly inhibited assembly. The effect on P-site binding and polypeptide synthesis is under study. These results show (1) none of the modified bases of 16S RNA are essential for protein synthesis, (2) substitution of A for C1400 has little functional effect, and (3) position 1400 may be important for ribosome assembly

  12. Distinct genetic lineages of Bactrocera caudata (Insecta: Tephritidae) revealed by COI and 16S DNA sequences.

    Science.gov (United States)

    Lim, Phaik-Eem; Tan, Ji; Suana, I Wayan; Eamsobhana, Praphathip; Yong, Hoi Sen

    2012-01-01

    The fruit fly Bactrocera caudata is a pest species of economic importance in Asia. Its larvae feed on the flowers of Cucurbitaceae such as Cucurbita moschata. To-date it is distinguished from related species based on morphological characters. Specimens of B. caudata from Peninsular Malaysia and Indonesia (Bali and Lombok) were analysed using the partial DNA sequences of cytochrome c oxidase subunit I (COI) and 16S rRNA genes. Both gene sequences revealed that B. caudata from Peninsular Malaysia was distinctly different from B. caudata of Bali and Lombok, without common haplotype between them. Phylogenetic analysis revealed two distinct clades, indicating distinct genetic lineage. The uncorrected 'p' distance for COI sequences between B. caudata of Malaysia-Thailand-China and B. caudata of Bali-Lombok was 5.65%, for 16S sequences from 2.76 to 2.99%, and for combined COI and 16S sequences 4.45 to 4.46%. The 'p' values are distinctly different from intraspecific 'p' distance (0-0.23%). Both the B. caudata lineages are distinctly separated from related species in the subgenus Zeugodacus - B. ascita, B. scutellata, B. ishigakiensis, B. diaphora, B. tau, B. cucurbitae, and B. depressa. Molecular phylogenetic analysis indicates that the B. caudata lineages are closely related to B. ascita sp. B, and form a clade with B. scutellata, B. ishigakiensis, B. diaphora and B. ascita sp. A. This study provides additional baseline for the phylogenetic relationships of Bactrocera fruit flies of the subgenus Zeugodacus. Both the COI and 16S genes could be useful markers for the molecular differentiation and phylogenetic analysis of tephritid fruit flies. PMID:22615962

  13. Distinct genetic lineages of Bactrocera caudata (Insecta: Tephritidae) revealed by COI and 16S DNA sequences.

    Science.gov (United States)

    Lim, Phaik-Eem; Tan, Ji; Suana, I Wayan; Eamsobhana, Praphathip; Yong, Hoi Sen

    2012-01-01

    The fruit fly Bactrocera caudata is a pest species of economic importance in Asia. Its larvae feed on the flowers of Cucurbitaceae such as Cucurbita moschata. To-date it is distinguished from related species based on morphological characters. Specimens of B. caudata from Peninsular Malaysia and Indonesia (Bali and Lombok) were analysed using the partial DNA sequences of cytochrome c oxidase subunit I (COI) and 16S rRNA genes. Both gene sequences revealed that B. caudata from Peninsular Malaysia was distinctly different from B. caudata of Bali and Lombok, without common haplotype between them. Phylogenetic analysis revealed two distinct clades, indicating distinct genetic lineage. The uncorrected 'p' distance for COI sequences between B. caudata of Malaysia-Thailand-China and B. caudata of Bali-Lombok was 5.65%, for 16S sequences from 2.76 to 2.99%, and for combined COI and 16S sequences 4.45 to 4.46%. The 'p' values are distinctly different from intraspecific 'p' distance (0-0.23%). Both the B. caudata lineages are distinctly separated from related species in the subgenus Zeugodacus - B. ascita, B. scutellata, B. ishigakiensis, B. diaphora, B. tau, B. cucurbitae, and B. depressa. Molecular phylogenetic analysis indicates that the B. caudata lineages are closely related to B. ascita sp. B, and form a clade with B. scutellata, B. ishigakiensis, B. diaphora and B. ascita sp. A. This study provides additional baseline for the phylogenetic relationships of Bactrocera fruit flies of the subgenus Zeugodacus. Both the COI and 16S genes could be useful markers for the molecular differentiation and phylogenetic analysis of tephritid fruit flies.

  14. Distinct genetic lineages of Bactrocera caudata (Insecta: Tephritidae revealed by COI and 16S DNA sequences.

    Directory of Open Access Journals (Sweden)

    Phaik-Eem Lim

    Full Text Available The fruit fly Bactrocera caudata is a pest species of economic importance in Asia. Its larvae feed on the flowers of Cucurbitaceae such as Cucurbita moschata. To-date it is distinguished from related species based on morphological characters. Specimens of B. caudata from Peninsular Malaysia and Indonesia (Bali and Lombok were analysed using the partial DNA sequences of cytochrome c oxidase subunit I (COI and 16S rRNA genes. Both gene sequences revealed that B. caudata from Peninsular Malaysia was distinctly different from B. caudata of Bali and Lombok, without common haplotype between them. Phylogenetic analysis revealed two distinct clades, indicating distinct genetic lineage. The uncorrected 'p' distance for COI sequences between B. caudata of Malaysia-Thailand-China and B. caudata of Bali-Lombok was 5.65%, for 16S sequences from 2.76 to 2.99%, and for combined COI and 16S sequences 4.45 to 4.46%. The 'p' values are distinctly different from intraspecific 'p' distance (0-0.23%. Both the B. caudata lineages are distinctly separated from related species in the subgenus Zeugodacus - B. ascita, B. scutellata, B. ishigakiensis, B. diaphora, B. tau, B. cucurbitae, and B. depressa. Molecular phylogenetic analysis indicates that the B. caudata lineages are closely related to B. ascita sp. B, and form a clade with B. scutellata, B. ishigakiensis, B. diaphora and B. ascita sp. A. This study provides additional baseline for the phylogenetic relationships of Bactrocera fruit flies of the subgenus Zeugodacus. Both the COI and 16S genes could be useful markers for the molecular differentiation and phylogenetic analysis of tephritid fruit flies.

  15. CORE: a phylogenetically-curated 16S rDNA database of the core oral microbiome.

    Directory of Open Access Journals (Sweden)

    Ann L Griffen

    Full Text Available Comparing bacterial 16S rDNA sequences to GenBank and other large public databases via BLAST often provides results of little use for identification and taxonomic assignment of the organisms of interest. The human microbiome, and in particular the oral microbiome, includes many taxa, and accurate identification of sequence data is essential for studies of these communities. For this purpose, a phylogenetically curated 16S rDNA database of the core oral microbiome, CORE, was developed. The goal was to include a comprehensive and minimally redundant representation of the bacteria that regularly reside in the human oral cavity with computationally robust classification at the level of species and genus. Clades of cultivated and uncultivated taxa were formed based on sequence analyses using multiple criteria, including maximum-likelihood-based topology and bootstrap support, genetic distance, and previous naming. A number of classification inconsistencies for previously named species, especially at the level of genus, were resolved. The performance of the CORE database for identifying clinical sequences was compared to that of three publicly available databases, GenBank nr/nt, RDP and HOMD, using a set of sequencing reads that had not been used in creation of the database. CORE offered improved performance compared to other public databases for identification of human oral bacterial 16S sequences by a number of criteria. In addition, the CORE database and phylogenetic tree provide a framework for measures of community divergence, and the focused size of the database offers advantages of efficiency for BLAST searching of large datasets. The CORE database is available as a searchable interface and for download at http://microbiome.osu.edu.

  16. A Case of Sepsis in a 92-Year-Old Korean Woman Caused by Aerococcus urinae and Identified by Sequencing the 16S Ribosomal RNA Gene.

    Science.gov (United States)

    Lee, Min Young; Kim, Myeong Hee; Lee, Woo In; Kang, So Young; Jeon, You La

    2016-05-01

    Aerococcus urinae is an uncommon pathogen that was first identified in 1992. Herein, we report a case of bloodstream infection caused by A. urinae, which occurred in a 92-year-old Korean female patient with an underlying urologic infection who had altered consciousness. The blood culture yielded positive results for A. urinae; however, identifying A. urinae was challenging. Ultimately, we used 16S ribosomal RNA (rRNA) gene sequencing to identify the organism. The patient recovered after being treated with ertapenem and meropenem. To our knowledge, this is the first report of a case of A. urinae sepsis in South Korea. PMID:26868516

  17. Optimal eukaryotic 18S and universal 16S/18S ribosomal RNA primers and their application in a study of symbiosis.

    Science.gov (United States)

    Wang, Yong; Tian, Ren Mao; Gao, Zhao Ming; Bougouffa, Salim; Qian, Pei-Yuan

    2014-01-01

    Eukaryotic 18S ribosomal RNA (rRNA) gene primers that feature a wide coverage are critical in detecting the composition of eukaryotic microscopic organisms in ecosystems. Here, we predicted 18S rRNA primers based on consecutive conserved sites and evaluated their coverage efficiency and scope of application to different eukaryotic groups. After evaluation, eight of them were considered as qualified 18S primers based on coverage rate. Next, we examined common conserved regions in prokaryotic 16S and eukaryotic 18S rRNA sequences to design 16S/18S universal primers. Three 16S/18S candidate primers, U515, U1390 and U1492, were then considered to be suitable for simultaneous amplification of the rRNA sequences in three domains. Eukaryotic 18S and prokaryotic 16S rRNA genes in a sponge were amplified simultaneously using universal primers U515 and U1390, and the subsequent sorting of pyrosequenced reads revealed some distinctive communities in different parts of the sample. The real difference in biodiversity between prokaryotic and eukaryotic symbionts could be discerned as the dissimilarity between OTUs was increased from 0.005 to 0.1. A network of the communities in external and internal parts of the sponge illustrated the co-variation of some unique microbes in certain parts of the sponge, suggesting that the universal primers are useful in simultaneous detection of prokaryotic and eukaryotic microbial communities.

  18. Optimal eukaryotic 18S and universal 16S/18S ribosomal RNA primers and their application in a study of symbiosis.

    Directory of Open Access Journals (Sweden)

    Yong Wang

    Full Text Available Eukaryotic 18S ribosomal RNA (rRNA gene primers that feature a wide coverage are critical in detecting the composition of eukaryotic microscopic organisms in ecosystems. Here, we predicted 18S rRNA primers based on consecutive conserved sites and evaluated their coverage efficiency and scope of application to different eukaryotic groups. After evaluation, eight of them were considered as qualified 18S primers based on coverage rate. Next, we examined common conserved regions in prokaryotic 16S and eukaryotic 18S rRNA sequences to design 16S/18S universal primers. Three 16S/18S candidate primers, U515, U1390 and U1492, were then considered to be suitable for simultaneous amplification of the rRNA sequences in three domains. Eukaryotic 18S and prokaryotic 16S rRNA genes in a sponge were amplified simultaneously using universal primers U515 and U1390, and the subsequent sorting of pyrosequenced reads revealed some distinctive communities in different parts of the sample. The real difference in biodiversity between prokaryotic and eukaryotic symbionts could be discerned as the dissimilarity between OTUs was increased from 0.005 to 0.1. A network of the communities in external and internal parts of the sponge illustrated the co-variation of some unique microbes in certain parts of the sponge, suggesting that the universal primers are useful in simultaneous detection of prokaryotic and eukaryotic microbial communities.

  19. Differentiation Between Bacillus thuringiensis and Bacillus cereus by 16S rDNA-PCR and ERIC-PCR

    Institute of Scientific and Technical Information of China (English)

    LI Haitao; LIU Dongming; GAO Jiguo

    2011-01-01

    16S rDNA and ERIC (Enterobacteia Repetitive Intergenic Consensus Sequences) based on PCR method were tested for the effectiveness of the differentiation of B. thuringiensis and B. cereus. 16S rDNA-PCR primers were designed based on the sequence difference in variable regions of B. cereus 16S rDNA and B. thuringiensis 16S rDNA, 16S rDNA-PCR showed no obvious difference between B. cereus and B. thuringiensis. The only difference was that one 1600-bp amplificon could be obtained from all the three B. Cereus strains, and none amplificon from any B. thuringiensis strains. ERIC was optimized based on previous reports. The genonlic DNA was used for the template of ER1C-PCR, and the following DNA fingerprints were analyzed by the agarose gel electrophoresis. The results showed that DNA fingerprint of three B. thuringiensis strains had a unique amplicon less than 100-bp, while DNA fingerprint of three B. cereus" strains had none. Moreover, DNA fingerprint of B. cereus showed a 700-bp amplicon, but didn't have any DNA fingerprints ofB. thuringiensis genome. Therefore, ERIC-PCR technique should be able to be used for the differentiation of B. thuringiensis and B. cereus.

  20. The use of 16s rDNA methods in soil microbial ecology Uso de métodos 16S rDNA em ecologia microbiana do solo

    OpenAIRE

    Andrew Macrae

    2000-01-01

    New and exciting molecular methods, many using the 16S small sub-unit ribosomal nucleic acid molecule, are opening the microbial "black box" in soil. These studies have added much to our knowledge of microbial diversity in soils, and are beginning to advance our understanding of the relationship between this diversity and its function in soil processes. Over the next few years, the knowledge gained from molecular studies will, we hope, lead to improvements in sustainable land management and s...

  1. FastGroupII: A web-based bioinformatics platform for analyses of large 16S rDNA libraries

    Directory of Open Access Journals (Sweden)

    McNairnie Pat

    2006-02-01

    Full Text Available Abstract Background High-throughput sequencing makes it possible to rapidly obtain thousands of 16S rDNA sequences from environmental samples. Bioinformatic tools for the analyses of large 16S rDNA sequence databases are needed to comprehensively describe and compare these datasets. Results FastGroupII is a web-based bioinformatics platform to dereplicate large 16S rDNA libraries. FastGroupII provides users with the option of four different dereplication methods, performs rarefaction analysis, and automatically calculates the Shannon-Wiener Index and Chao1. FastGroupII was tested on a set of 16S rDNA sequences from coral-associated Bacteria. The different grouping algorithms produced similar, but not identical, results. This suggests that 16S rDNA datasets need to be analyzed in multiple ways when being used for community ecology studies. Conclusion FastGroupII is an effective bioinformatics tool for the trimming and dereplication of 16S rDNA sequences. Several standard diversity indices are calculated, and the raw sequences are prepared for downstream analyses.

  2. Diversity of 16S rDNA and environmental factor influencing microorganisms in Malan ice core

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The research on extrempholic microorganisms in glacial low-temperature environment receives more attention than ever before. Due to the successive chronological records in ice core, it is important to initiate microbiological studies on ice core samples. 23 samples from one ice core, drilled from central Qinghai-Tibetan Plateau, were analyzed. The number of total microorganisms and culturable microorganisms in different layers showed that it related with the content of dust in ice. It is suggested that the distribution of microorganisms in ice depends on the transportation of materials during glacier development. The bacteria diversity in Malan Glacier was analyzed by 16S rDNA sequencing methods, which showed that many sequences were similar to known psychrophilic bacteria.

  3. Expression of protein-coding genes embedded in ribosomal DNA

    DEFF Research Database (Denmark)

    Johansen, Steinar D; Haugen, Peik; Nielsen, Henrik

    2007-01-01

    Ribosomal DNA (rDNA) is a specialised chromosomal location that is dedicated to high-level transcription of ribosomal RNA genes. Interestingly, rDNAs are frequently interrupted by parasitic elements, some of which carry protein genes. These are non-LTR retrotransposons and group II introns that e...... in the nucleolus....

  4. Regulation of ribosomal DNA amplification by the TOR pathway.

    Science.gov (United States)

    Jack, Carmen V; Cruz, Cristina; Hull, Ryan M; Keller, Markus A; Ralser, Markus; Houseley, Jonathan

    2015-08-01

    Repeated regions are widespread in eukaryotic genomes, and key functional elements such as the ribosomal DNA tend to be formed of high copy repeated sequences organized in tandem arrays. In general, high copy repeats are remarkably stable, but a number of organisms display rapid ribosomal DNA amplification at specific times or under specific conditions. Here we demonstrate that target of rapamycin (TOR) signaling stimulates ribosomal DNA amplification in budding yeast, linking external nutrient availability to ribosomal DNA copy number. We show that ribosomal DNA amplification is regulated by three histone deacetylases: Sir2, Hst3, and Hst4. These enzymes control homologous recombination-dependent and nonhomologous recombination-dependent amplification pathways that act in concert to mediate rapid, directional ribosomal DNA copy number change. Amplification is completely repressed by rapamycin, an inhibitor of the nutrient-responsive TOR pathway; this effect is separable from growth rate and is mediated directly through Sir2, Hst3, and Hst4. Caloric restriction is known to up-regulate expression of nicotinamidase Pnc1, an enzyme that enhances Sir2, Hst3, and Hst4 activity. In contrast, normal glucose concentrations stretch the ribosome synthesis capacity of cells with low ribosomal DNA copy number, and we find that these cells show a previously unrecognized transcriptional response to caloric excess by reducing PNC1 expression. PNC1 down-regulation forms a key element in the control of ribosomal DNA amplification as overexpression of PNC1 substantially reduces ribosomal DNA amplification rate. Our results reveal how a signaling pathway can orchestrate specific genome changes and demonstrate that the copy number of repetitive DNA can be altered to suit environmental conditions.

  5. Heterogeneity of Pumpkin Ribosomal DNA 1

    Science.gov (United States)

    Siegel, Albert; Kolacz, Kathryn

    1983-01-01

    The ribosomal DNA (rDNA) of Cucurbita pepo L. has been found to consist of tandemly arrayed repeat units, most of which are 10 kilobases in length. Thirty-six repeat units, cloned into the HindIII site of pACYC 177, fall into seven classes which differ from each other in length and/or nucleotide sequence. Most of the heterogeneity occurs in noncoding portions of the repeat unit although there is some nucleotide sequence variation in the coding portion as well. Heterogeneity of base modification was observed in genomic rDNA of which two examples are: (a) all of the repeat units have three BamHI sites, one of which is unavailable for restriction in about half of the units and (b) all of the CCGG sites except one are methylated at the internal cytidine in many of the units; a second site is unmethylated in some of the units and in a very few units a third site remains unmethylated. Images Fig. 1 Fig. 3 PMID:16662953

  6. The structure of Aquifex aeolicus ribosomal protein S8 reveals a unique subdomain that contributes to an extremely tight association with 16S rRNA.

    Science.gov (United States)

    Menichelli, Elena; Edgcomb, Stephen P; Recht, Michael I; Williamson, James R

    2012-01-20

    The assembly of ribonucleoprotein complexes occurs under a broad range of conditions, but the principles that promote assembly and allow function at high temperature are poorly understood. The ribosomal protein S8 from Aquifex aeolicus (AS8) is unique in that there is a 41-residue insertion in the consensus S8 sequence. In addition, AS8 exhibits an unusually high affinity for the 16S ribosomal RNA, characterized by a picomolar dissociation constant that is approximately 26,000-fold tighter than the equivalent interaction from Escherichia coli. Deletion analysis demonstrated that binding to the minimal site on helix 21 occurred at the same nanomolar affinity found for other bacterial species. The additional affinity required the presence of a three-helix junction between helices 20, 21, and 22. The crystal structure of AS8 was solved, revealing the helix-loop-helix geometry of the unique AS8 insertion region, while the core of the molecule is conserved with known S8 structures. The AS8 structure was modeled onto the structure of the 30S ribosomal subunit from E. coli, suggesting the possibility that the unique subdomain provides additional backbone and side-chain contacts between the protein and an unpaired base within the three-way junction of helices 20, 21, and 22. Point mutations in the protein insertion subdomain resulted in a significantly reduced RNA binding affinity with respect to wild-type AS8. These results indicate that the AS8-specific subdomain provides additional interactions with the three-way junction that contribute to the extremely tight binding to ribosomal RNA. PMID:22079365

  7. The structure of Aquifex aeolicus ribosomal protein S8 reveals a unique subdomain that contributes to an extremely tight association with 16S rRNA.

    Science.gov (United States)

    Menichelli, Elena; Edgcomb, Stephen P; Recht, Michael I; Williamson, James R

    2012-01-20

    The assembly of ribonucleoprotein complexes occurs under a broad range of conditions, but the principles that promote assembly and allow function at high temperature are poorly understood. The ribosomal protein S8 from Aquifex aeolicus (AS8) is unique in that there is a 41-residue insertion in the consensus S8 sequence. In addition, AS8 exhibits an unusually high affinity for the 16S ribosomal RNA, characterized by a picomolar dissociation constant that is approximately 26,000-fold tighter than the equivalent interaction from Escherichia coli. Deletion analysis demonstrated that binding to the minimal site on helix 21 occurred at the same nanomolar affinity found for other bacterial species. The additional affinity required the presence of a three-helix junction between helices 20, 21, and 22. The crystal structure of AS8 was solved, revealing the helix-loop-helix geometry of the unique AS8 insertion region, while the core of the molecule is conserved with known S8 structures. The AS8 structure was modeled onto the structure of the 30S ribosomal subunit from E. coli, suggesting the possibility that the unique subdomain provides additional backbone and side-chain contacts between the protein and an unpaired base within the three-way junction of helices 20, 21, and 22. Point mutations in the protein insertion subdomain resulted in a significantly reduced RNA binding affinity with respect to wild-type AS8. These results indicate that the AS8-specific subdomain provides additional interactions with the three-way junction that contribute to the extremely tight binding to ribosomal RNA.

  8. Characterization of copy numbers of 16S rDNA and 16S rRNA of Candidatus Liberibacter asiaticus and the implication in detection in planta using quantitative PCR

    Directory of Open Access Journals (Sweden)

    Wang Nian

    2009-03-01

    Full Text Available Abstract Background Citrus Huanglongbing (HLB is one of the most devastating diseases on citrus and is associated with Candidatus Liberibacter spp.. The pathogens are phloem limited and have not been cultured in vitro. The current management strategy of HLB is to remove infected citrus trees and reduce psyllid populations with insecticides to prevent the spreading. This strategy requires sensitive and reliable diagnostic methods for early detection. Results We investigated the copy numbers of the 16S rDNA and 16S rRNA of the HLB pathogen and the implication of improving the diagnosis of HLB for early detection using Quantitative PCR. We compared the detection of HLB with different Quantitative PCR based methods with primers/probe targeting either 16S rDNA, beta-operon DNA, 16S rRNA, or beta-operon RNA. The 16S rDNA copy number of Ca. Liberibacter asiaticus was estimated to be three times of that of the beta-operon region, thus allowing detection of lower titer of Ca. L. asiaticus. Quantitative reverse transcriptional PCR (QRT-PCR indicated that the 16S rRNA averaged 7.83 times more than that of 16S rDNA for the same samples. Dilution analysis also indicates that QRT-PCR targeting 16S rRNA is 10 time more sensitive than QPCR targeting 16S rDNA. Thus QRT-PCR was able to increase the sensitivity of detection by targeting 16S rRNA. Conclusion Our result indicates that Candidatus Liberibacter asiaticus contains three copies of 16S rDNA. The copy number of 16S rRNA of Ca. L. asiaticus in planta averaged about 7.8 times of 16S rDNA for the same set of samples tested in this study. Detection sensitivity of HLB could be improved through the following approaches: using 16S rDNA based primers/probe in the QPCR assays; and using QRT-PCR assays targeting 16S rRNA.

  9. Effects of 16S rDNA sampling on estimates of the number of endosymbiont lineages in sucking lice.

    Science.gov (United States)

    Allen, Julie M; Burleigh, J Gordon; Light, Jessica E; Reed, David L

    2016-01-01

    Phylogenetic trees can reveal the origins of endosymbiotic lineages of bacteria and detect patterns of co-evolution with their hosts. Although taxon sampling can greatly affect phylogenetic and co-evolutionary inference, most hypotheses of endosymbiont relationships are based on few available bacterial sequences. Here we examined how different sampling strategies of Gammaproteobacteria sequences affect estimates of the number of endosymbiont lineages in parasitic sucking lice (Insecta: Phthirapatera: Anoplura). We estimated the number of louse endosymbiont lineages using both newly obtained and previously sequenced 16S rDNA bacterial sequences and more than 42,000 16S rDNA sequences from other Gammaproteobacteria. We also performed parametric and nonparametric bootstrapping experiments to examine the effects of phylogenetic error and uncertainty on these estimates. Sampling of 16S rDNA sequences affects the estimates of endosymbiont diversity in sucking lice until we reach a threshold of genetic diversity, the size of which depends on the sampling strategy. Sampling by maximizing the diversity of 16S rDNA sequences is more efficient than randomly sampling available 16S rDNA sequences. Although simulation results validate estimates of multiple endosymbiont lineages in sucking lice, the bootstrap results suggest that the precise number of endosymbiont origins is still uncertain. PMID:27547523

  10. A new model for the three-dimensional folding of Escherichia coli 16 S ribosomal RNA. II. The RNA-protein interaction data.

    Science.gov (United States)

    Mueller, F; Brimacombe, R

    1997-08-29

    The map of the mass centres of the 21 proteins from the Escherichia coli 30 S ribosomal subunit, as determined by neutron scattering, was fitted to a cryoelectron microscopic (cryo-EM) model at a resolution of 20 A of 70 S ribosomes in the pre-translocational state, carrying tRNA molecules at the A and P sites. The fit to the 30 S moiety of the 70 S particles was accomplished with the help of the well-known distribution of the ribosomal proteins in the head, body and side lobe regions of the 30 S subunit, as determined by immuno electron microscopy (IEM). Most of the protein mass centres were found to lie close to the surface (or even outside) of the cryo-EM contour of the 30 S subunit, supporting the idea that the ribosomal proteins are arranged peripherally around the rRNA. The ribosomal protein distribution was then compared with the corresponding model for the 16 S rRNA, fitted to the same EM contour (described in an accompanying paper), in order to analyse the mutual compatibility of the arrangement of proteins and rRNA in terms of the available RNA-protein interaction data. The information taken into account included the hydroxyl radical and base foot-printing data from Noller's laboratory, and our own in situ cross-linking results. Proteins S1 and S14 were not considered, due to the lack of RNA-protein data. Among the 19 proteins analysed, 12 (namely S2, S4, S5, S7, S8, S9, S10, S11, S12, S15, S17 and S21) showed a fit to the rRNA model that varied from being excellent to at least acceptable. Of the remaining 7, S3 and S13 showed a rather poor fit, as did S18 (which is considered in combination with S6 in the foot-printing experiments). S16 was difficult to evaluate, as the foot-print data for this protein cover a large area of the rRNA. S19 and S20 showed a bad fit in terms of the neutron map, but their foot-print and cross-link sites were clustered into compact groups in the rRNA model in those regions of the 30 S subunit where these proteins have

  11. Characterization of Bacterial Community Structure and Diversity in Rhizosphere Soils of Three Plants in Rapidly Changing Salt Marshes Using 16S rDNA

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The structure and diversity of the bacterial communities in rhizosphere soils of native Phragmites australis and Scirpus mariqueter and alien Spartina alterniflora in the Yangtze River Estuary were investigated by constructing 16S ribosomal DNA (rDNA) clone libraries. The bacterial diversity was quantified by placing the clones into operational taxonomic unit (OTU) groups at the level of sequence similarity of > 97%. Phylogenetic analysis of the resulting 398 clone sequences indicated a high diversity of bacteria in the rhizosphere soils of these plants. The members of Alphaproteobacteria,Betaproteobacteria, Gammaproteobacteria, and Deltaproteobacteria of the phylum Proteobacteria were the most abundant in rhizobacteria. Chao 1 nonparametric diversity estimator coupled with the reciprocal of Simpson's index (1/D) was applied to sequence data obtained from each library to evaluate total sequence diversity and quantitatively compare the level of dominance. The results showed that Phragmites, Scirpus, and Spartina rhizosphere soils contained 200, 668, and 382 OTUs, respectively. The bacterial communities in the Spartina and Phragmites rhizosphere soils displayed species dominance revealed by 1/D, whereas the bacterial community in Scirpus rhizosphere soil had uniform distributions of species abundance. Overall, analysis of 16S rDNA clone libraries from the rhizosphere soils indicates that the changes in bacterial composition may occur concomitantly with the shift of species composition in plant communities.

  12. Characterization of viable bacteria from Siberian permafrost by 16S rDNA sequencing

    Science.gov (United States)

    Shi, T.; Reeves, R. H.; Gilichinsky, D. A.; Friedmann, E. I.

    1997-01-01

    Viable bacteria were found in permafrost core samples from the Kolyma-Indigirka lowland of northeast Siberia. The samples were obtained at different depths; the deepest was about 3 million years old. The average temperature of the permafrost is -10 degrees C. Twenty-nine bacterial isolates were characterized by 16S rDNA sequencing and phylogenetic analysis, cell morphology, Gram staining, endospore formation, and growth at 30 degrees C. The majority of the bacterial isolates were rod shaped and grew well at 30 degrees C; but two of them did not grow at or above 28 degrees C, and had optimum growth temperatures around 20 degrees C. Thirty percent of the isolates could form endospores. Phylogenetic analysis revealed that the isolates fell into four categories: high-GC Gram-positive bacteria, beta-proteobacteria, gamma-proteobacteria, and low-GC Gram-positive bacteria. Most high-GC Gram-positive bacteria and beta-proteobacteria, and all gamma-proteobacteria, came from samples with an estimated age of 1.8-3.0 million years (Olyor suite). Most low-GC Gram-positive bacteria came from samples with an estimated age of 5,000-8,000 years (Alas suite).

  13. 细菌16 S核糖体RNA基因检测杰氏棒状杆菌一株%Identification of corynebacterium jeikeium by detection of bacterial 16s ribosomal RNA gene

    Institute of Scientific and Technical Information of China (English)

    崔颖鹏; 黄朱亮

    2015-01-01

    Objective To detect clinical strain by amplifying 16S ribosomal RNA( 16S rRNA) gene with polymerase chain reaction ( PCR) method. Methods 16S rRNA gene was amplifyied by universal primers P1,P2 with polymerase chain reaction,and the polymerase chain reaction products were sequenced to achieve the DNA sequences. Results PCR products were about 1 465bp, and the PCR sequences were blasted in NCBI web to achieve the proper strain name,with the use of this method,the unkown gram⁃positive bacilli strain was identified as corynebacterium jeikeium strain, ATCC25923 was identified as a strain of staphylococcus aureus and negative control was also specific.Conclusion 16S rRNA gene detection can be used as strain identification,and especially for some less common clinical strains.%目的:探讨通过16S核糖体RNA(16S rRNA )基因测序的方法用于临床菌株鉴定。方法以细菌16S rRNA基因为靶序列,采用细菌的通用引物P1、P2进行PCR扩增,同时送到测序公司测序从而达到鉴定。结果待测菌株及ATCC25923阳性对照通过PCR得到的扩增片段为1465bp左右,待测菌株经测序比对鉴定为一株杰氏棒状杆菌,阳性质控ATCC25923鉴定为一株金黄的葡萄球菌,阴性对照未出现任何结果。结论通过PCR检测细菌16srRNA基因可以应用于临床菌株的鉴定,并且适用一些难以鉴定的细菌。

  14. Analysis of the 16S-23S rDNA intergenic spacers (IGSs) of marine vibrios for species-specific signature DNA sequences.

    Science.gov (United States)

    Lee, Simon K Y; Wang, H Z; Law, Sheran H W; Wu, Rudolf S S; Kong, Richard Y C

    2002-05-01

    Vibrios are widespread in the marine environment and a few pathogenic species are known to be commonly associated with outbreaks of diarrheal diseases in humans due to the consumption of raw or improperly cooked seafood. However, there are also many Vibrio species which are potentially pathogenic to vertebrate and invertebrate aquatic animals, and of which little is known. In an attempt to develop rapid PCR detection methods for these latter class of vibrios, we have examined the 16S-23S intergenic spacers (IGSs) of 10 lesser-known Vibrio species and successfully developed species-specific primers for eight of them--Vibrio costicola, V. diazotrophicus, V. fluvialis, V. nigripulchritudo, V. proteolyticus, V. salmonicida, V. splendidus and V. tubiashii. The IGS amplicons were amplified using primers complementary to conserved regions of the 16S and 23S rRNA genes, and cloned into plasmid vectors and sequenced. Analysis of the IGS sequences showed that 37 ribosomal RNA (rrn) operons representing seven different IGS types have been cloned from the 10 vibrios. The three IGS types--IGS(0), IGS(IA) and IGS(Glu)--were the most prevalent forms detected. Multiple alignment of representative sequences of these three IGS types from different Vibrio species revealed several domains of high sequence variability, which were used to design species-specific primers for PCR. The specificity of the primers were evaluated using total DNA prepared from different Vibrio species and bacterial genera. The results showed that the PCR method can be used to reliably detect eight of the 10 Vibrio species in marine waters in this study.

  15. 福建华溪蟹线粒体DNA COI和16S rRNA基因序列的遗传多样性%Genetic diversity on mitochondrial DNA COI and 16S rRNA of Sinopotamon fukienense

    Institute of Scientific and Technical Information of China (English)

    石林波; 张小燕; 汪雁; 王云龙; 周宪民; 邹节新

    2013-01-01

    目的 探讨福建华溪蟹(Sinopotamonfukienense)的遗传多样性.方法 采用PCR结合DNA测序技术,测定S.fukienense的线粒体COI和16S rRNA基因序列的组成.经比对获得639 bp长度的COI基因序列和526 bp的16S rRNA基因序列,以对比分析S.fukienense的遗传多样性.结果 S.fukienense基于COI基因核苷酸多样性(Pi)为0.048 4,高于其基于16S rRNA基因核苷酸多样性(Pi)为0.021 6.同时,S.fukienense基于COI基因单倍型间的平均遗传距离(P)为0.048,大于其基于16S rRNA基因单倍型间的平均遗传距离(P)0.026.结论 COI序列在分析S.fukienense遗传异变时的作用更优于16S rRNA基因序列.%The aim of this study was to explore the genetic diversity of the freshwater crab S.fukienense based on the gene sequence CO I and 16S rRNA.The genes of CO I and 16S rRNA were amplified with PCR and subsequently sequenced.The base composition and sequence variation of them were analyed with Mega version 4.0 and DnaSP version 4.10.We obtained 639 bp nucleotide sequence of gene COI and 526 bp nucleotide sequence of gene 16S rRNA.The nucleotide diversity based on gene COI (Pi=0.048 4) was higher than that based on 16S rRNA (Pi=0.021 6).At the same time,the average genetic distance of haplotypes based on gene COI (P=0.048) was larger than that based on 16S rRNA (P=0.026).Results suggest that the COI sequence is better than the 16S rRNA sequence in the analysis of genetic mutation for S.fukienense.

  16. Investigating bacterial populations in styrene-degrading biofilters by 16S rDNA tag pyrosequencing.

    Science.gov (United States)

    Portune, Kevin J; Pérez, M Carmen; Álvarez-Hornos, F Javier; Gabaldón, Carmen

    2015-01-01

    Microbial biofilms are essential components in the elimination of pollutants within biofilters, yet still little is known regarding the complex relationships between microbial community structure and biodegradation function within these engineered ecosystems. To further explore this relationship, 16S rDNA tag pyrosequencing was applied to samples taken at four time points from a styrene-degrading biofilter undergoing variable operating conditions. Changes in microbial structure were observed between different stages of biofilter operation, and the level of styrene concentration was revealed to be a critical factor affecting these changes. Bacterial genera Azoarcus and Pseudomonas were among the dominant classified genera in the biofilter. Canonical correspondence analysis (CCA) and correlation analysis revealed that the genera Brevundimonas, Hydrogenophaga, and Achromobacter may play important roles in styrene degradation under increasing styrene concentrations. No significant correlations (P > 0.05) could be detected between biofilter operational/functional parameters and biodiversity measurements, although biological heterogeneity within biofilms and/or technical variability within pyrosequencing may have considerably affected these results. Percentages of selected bacterial taxonomic groups detected by fluorescence in situ hybridization (FISH) were compared to results from pyrosequencing in order to assess the effectiveness and limitations of each method for identifying each microbial taxon. Comparison of results revealed discrepancies between the two methods in the detected percentages of numerous taxonomic groups. Biases and technical limitations of both FISH and pyrosequencing, such as the binding of FISH probes to non-target microbial groups and lack of classification of sequences for defined taxonomic groups from pyrosequencing, may partially explain some differences between the two methods.

  17. Phylogenetic analysis of Thai oyster (Ostreidae) based on partial sequences of the mitochondrial 16S rDNA gene

    DEFF Research Database (Denmark)

    Bussarawit, Somchai; Gravlund, Peter; Glenner, Henrik;

    2006-01-01

    Ten oyster species of the family Ostreidae (Subfamilies Crassostreinae and Lophinae) from Thailand were studied using morphological data and mitochondrial 16S rDNA gene sequences. Additional sequence data from five specimens of Ostreidae and one specimen of Tridacna gigas were downloaded from Gen...

  18. Diagnóstico de Mycoplasma genitalium por amplificación de los genes MgPa y ARN ribosomal 16S Diagnosis of Mycoplasma genitalium by MgPa and rRNA 16S gene amplification

    Directory of Open Access Journals (Sweden)

    Carmen Fernández-Molina

    2008-10-01

    Full Text Available OBJETIVO: El microorganismo Mycoplasma genitalium se ha relacionado con la uretritis no gonocócica (UNG. La técnica de PCR se ha convertido en el principal método de detección de este patógeno. En consecuencia, debe aplicarse un método de diagnóstico mediante la amplificación de fragmentos de ADN por la técnica PCR. MATERIAL Y MÉTODOS: Se seleccionaron los cebadores MGF-MGR y MgPaF-MgPaR, complementarios de los genes de ARNr 16S y MgPa de M. genitalium, respectivamente. Se efectuaron ensayos de especificidad y sensibilidad y se estudiaron muestras clínicas. RESULTADOS: La PCR con cada grupo de cebadores utilizado fue específica sólo para M. genitalium y la sensibilidad fue mayor con el grupo de cebadores MGF-MGR. En el estudio de 34 muestras clínicas, 18.5% fue positivo a M. genitalium y se encontró un mayor número de muestras positivas al utilizar los cebadores MgPaF-MgPaR. CONCLUSIONES: Debe aplicarse en la práctica clínica el diagnóstico de M. genitalium mediante la amplificación del ADN por PCR en los pacientes con UNG.OBJECTIVE: Mycoplasma genitalium has been associated with nongonococcal urethritis (NGU. Diagnosis by PCR has become the primary detection method for this organism. Thus, diagnosis by DNA amplification using the PCR technique should be utilized. MATERIAL AND METHODS: GMF/GMR and MgpF/MgpR primer pairs, complementary to the M. genitalium 16S rRNA and MgPa genes, respectively, were selected. Specificity and sensibility assays were conducted and clinical samples were studied. RESULTS: The PCR with each primer pair was specific only for M. genitalium, and the sensibility was higher with the GMF/GMR primers. In the study of 34 clinical samples, 18,5% were positive for M. genitalium, with more positive samples when the MgpF/MgpR primers were used. CONCLUSIONS: DNA amplification by PCR should be applied in clinical practice to the diagnosis of M. genitalium in patients with NGU should using.

  19. Sequencing of an atypical Brucella strain 16S rDNA%1株非典型布鲁杆菌的16S rDNA序列分析

    Institute of Scientific and Technical Information of China (English)

    刘志国; 王妙; 刘日宏; 崔步云

    2015-01-01

    目的 分析非典型布鲁杆菌的16S rDNA序列,评价16S rDNA序列测定方法鉴定布鲁杆菌的可行性.方法 用常规方法对l株非典型菌株进行初步鉴定;提取菌株的DNA,双向测定16S rDNA全序列,在NCBI对该序列进行Blast比对,用DNAMAN软件进行菌株的16S rDNA序列一致性比对;同时,从GenBank下载与布鲁杆菌有血清学交叉反应菌株的16S rDNA全序列,用MEGA 6.0构建16S rDNA系统发生树.结果 常规鉴定显示,试验菌株为非典型布鲁杆菌.试验菌株的16S rDNA序列与布鲁杆菌基因的相似性为99%,与牛种布鲁杆菌544A、羊种布鲁杆菌16M的16S rDNA序列的一致性为96.99%.系统发生树显示,试验菌株为布鲁杆菌,且与牛种布鲁杆菌544A、羊种布鲁杆菌16M有较为密切的亲缘关系.结论 试验菌株为非典型布鲁杆菌,16S rDNA序列测定是一种简便、快速、准确的非典型布鲁杆菌鉴定方法.%Objective To sequence an atypical Brucella strain 16S rDNA,and to evaluate the feasibility of 16S rDNA sequencing method for identification of Brucella.Methods Preliminary identification of atypical strains was carried out with conventional method.Strain DNA was extracted,and 16S rDNA complete sequence was bidirectional sequenced,and Blast in NCBI and DNAMAN software were used for comparison of the sequence identities of the 16S rDNA.Moreover,16S rDNA complete sequence of the stains those were known to cross-react serologically with Brucella was downloaded from GenBank,MEGA 6.0 was used to construct the phylogenetic tree.Results The conventional identification results revealed that it was an atypical Brucella,the gene similarity between the sequences of the test strain 16S rDNA and Brucella was 99%,between 16S rDNA sequence of Brucella abortus 544A and Brucella melitensis 16M was 96.99%.Phylogenetic tree revealed that the test stain was a Brucella,and closely related to Brucella abortus 544A and Brucella melitensis 16M.Conclusion The

  20. Mutation detection analysis of a region of 16S-like ribosomal RNA gene of Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii

    Directory of Open Access Journals (Sweden)

    Khairnar Krishna

    2008-09-01

    Full Text Available Abstract Background The level of intra-species genetic variation in Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii populations in a localized geographic area, like Puducherry, India, remains unknown. Methods In the present study the existence of genetic variation in the nested multiplex polymerase chain reaction (NM-PCR amplified region of the 16S-like ribosomal RNA genes of E. histolytica, E. dispar and E. moshkovskii was investigated by riboprinting and single strand conformation polymorphism (SSCP analysis. Results We found that 70 stool specimens were positive for E. histolytica, 171 stool specimens were positive for E. dispar, and 37 stool specimens were positive for E. moshkovskii by NM-PCR. Ninety liver abscess pus specimens, 21 urine specimens, and 8 saliva specimens were positive for E. histolytica by NM-PCR. Riboprinting analysis detected a mutation in the PCR product of only one E. histolytica isolate from a stool specimen. However, SSCP analysis detected mutations in the PCR products of five E. histolytica isolates and three E. moshkovskii isolates from stool specimens, and one E. histolytica isolate from a saliva specimen. The mutations detected by riboprinting and SSCP analysis were confirmed by sequencing. All the nucleotide sequences showing mutations in this study have already been deposited into the NCBI GenBank database under accession numbers [GenBank: EF682200 to GenBank: EF682208]. Conclusion The present study has revealed the subsistence of mutations in the ribosomal RNA genes of E. histolytica and E. moshkovskii, which points towards the existence of intra-species genetic variation in E. histolytica and E. moshkovskii isolates infecting humans.

  1. Bacterial diversity in the Uranium mill-tailings Gittersee as estimated via a 16S rDNA approach

    International Nuclear Information System (INIS)

    Bacterial diversity in a soil sample collected from uranium mill-tailings called Gittersee and situated near the city of Dresden, Germany, was analysed by using a culture-independent 16S rDNA approach exploiting PCR amplification primers 7F and 1513R. The results were compared with those obtained earlier analysing the same sample by using another primer pair, namely 43F-1404R. The two 16S rDNA approaches demonstrated that Proteobacteria were the most predominant group in the sample, followed by Cytophaga/Flavobacterium/ Bacteroidesand by Gram positive bacteria with low and also with high G+C content too. A large number of 16S rDNA sequences from two libraries were identical or almost identical. However, the ratio between the bacterial groups represented in them significantly differed. 7F-1513R primer set retrieved in addition to the above mentioned sequences, also 16S rRNA of green non-sulphur bacteria and representatives of the AD1 and the OP11 divisions. The latter indicates that the 7F-1513R primer set seems to be more reliable in analyses of bacterial diversity. (authors)

  2. Characterization of ribosomal DNA (rDNA in Drosophila arizonae

    Directory of Open Access Journals (Sweden)

    Francisco Javier Tovar

    2000-06-01

    Full Text Available Ribosomal DNA (rDNA is a multigenic family composed of one or more clusters of repeating units (RU. Each unit consists of highly conserved sequences codifying 18S, 5.8S and 28S rRNA genes intercalated with poorly conserved regulatory sequences between species. In this work, we analyzed the rDNA of Drosophila arizonae, a member of the mulleri complex (Repleta group. Using genomic restriction patterns, cloning and mapping of some representative rDNA fragments, we were able to construct a representative restriction map. RU in this species are 13.5-14 kb long, restriction sites are completely conserved compared with other drosophilids and the rDNA has an R1 retrotransposable element in some RU. We were unable to detect R2 elements in this species.O DNA ribossômico (rDNA é uma família multigênica composta de um ou mais aglomerados de unidades de repetição (RU. Cada unidade consiste de seqüências altamente conservadas que codificam os rRNAs 18S, 5.8S e 28S, intercaladas com seqüências regulatórias pouco conservadas entre as espécies. Neste trabalho analisamos o rDNA de Drosophila arizonae, um membro do complexo mulleri (grupo Repleta. Usando padrões de restrição genômicos, clonagem e mapeamento de alguns fragmentos de rDNA representativos, estabelecemos um mapa de restrição do rDNA representativo desta espécie. Neste drosofilídeo, a RU tem um tamanho médio de 13.5-14 kb e os sítios de restrição estão completamente conservados com relação a outras drosófilas. Além disto, este rDNA possui um elemento transponível tipo R1 presente em algumas unidades. Neste trabalho não tivemos evidências da presença de elementos R2 no rDNA desta espécie.

  3. Bacterial diversity of soil under eucalyptus assessed by 16S rDNA sequencing analysis Diversidade bacteriana de solo sob eucaliptos obtida por seqüenciamento do 16S rDNA

    OpenAIRE

    Érico Leandro da Silveira; Rodrigo Matheus Pereira; Denilson César Scaquitto; Eliamar Aparecida Nascimbém Pedrinho; Silvana Pómpeia Val-Moraes; Ester Wickert; Lúcia Maria Carareto-Alves; Eliana Gertrudes Macedo Lemos

    2006-01-01

    Studies on the impact of Eucalyptus spp. on Brazilian soils have focused on soil chemical properties and isolating interesting microbial organisms. Few studies have focused on microbial diversity and ecology in Brazil due to limited coverage of traditional cultivation and isolation methods. Molecular microbial ecology methods based on PCR amplified 16S rDNA have enriched the knowledge of soils microbial biodiversity. The objective of this work was to compare and estimate the bacterial diversi...

  4. 海南温泉嗜热菌的16S rDNA分析%Hainan Hot Spring Thermophiles' 16S rDNA Analysis

    Institute of Scientific and Technical Information of China (English)

    吴红萍; 孟甜; 张飞官; 陈永安; 李文芳; 王丙乾; 王锐萍

    2013-01-01

    目的:确定24株海南温泉嗜热菌菌株的分类地位.方法:Blastn分析菌株16S rDNA序列同源性;邻接法构建菌株16S rDNA序列系统发育进化树并分析菌株的进化位置;Clustax比对分析菌株的相似度和进化距离.结果:菌株LY5和LY4的16S rDNA序列与Geobacillus pallidus strain B1,partial sequence(GenBank:HM030740.1)的16SrDNA序列同源性分别为98%和97%,其他菌株的16S rDNA序列与Geobacillus subterraneus,strain R-35641(GenBank:FN428689.1)的16S rDNA序列的同源性均大于96%.Clustax比对分析表明26株菌16S rDNA序列前段(1~70bp)、中段(70bp~1420bp)、后段(1420~1484bp)的相似度分别为40%、100%和60%,进化距离分析表明菌株GT7、LY4和LY5与其他菌株进化距离较远,其余菌株之间进化距离差异不明显.综上所述,初步将24株温泉嗜热菌鉴定为土芽孢杆菌属(Geobacillus sp.).结论:16S rDNA序列分析可用于温泉嗜热菌的鉴定.

  5. PCR primers for metazoan nuclear 18S and 28S ribosomal DNA sequences.

    Directory of Open Access Journals (Sweden)

    Ryuji J Machida

    Full Text Available BACKGROUND: Metagenetic analyses, which amplify and sequence target marker DNA regions from environmental samples, are increasingly employed to assess the biodiversity of communities of small organisms. Using this approach, our understanding of microbial diversity has expanded greatly. In contrast, only a few studies using this approach to characterize metazoan diversity have been reported, despite the fact that many metazoan species are small and difficult to identify or are undescribed. One of the reasons for this discrepancy is the availability of universal primers for the target taxa. In microbial studies, analysis of the 16S ribosomal DNA is standard. In contrast, the best gene for metazoan metagenetics is less clear. In the present study, we have designed primers that amplify the nuclear 18S and 28S ribosomal DNA sequences of most metazoan species with the goal of providing effective approaches for metagenetic analyses of metazoan diversity in environmental samples, with a particular emphasis on marine biodiversity. METHODOLOGY/PRINCIPAL FINDINGS: Conserved regions suitable for designing PCR primers were identified using 14,503 and 1,072 metazoan sequences of the nuclear 18S and 28S rDNA regions, respectively. The sequence similarity of both these newly designed and the previously reported primers to the target regions of these primers were compared for each phylum to determine the expected amplification efficacy. The nucleotide diversity of the flanking regions of the primers was also estimated for genera or higher taxonomic groups of 11 phyla to determine the variable regions within the genes. CONCLUSIONS/SIGNIFICANCE: The identified nuclear ribosomal DNA primers (five primer pairs for 18S and eleven for 28S and the results of the nucleotide diversity analyses provide options for primer combinations for metazoan metagenetic analyses. Additionally, advantages and disadvantages of not only the 18S and 28S ribosomal DNA, but also other

  6. Influence of DNA extraction on oral microbial profiles obtained via 16S rRNA gene sequencing

    OpenAIRE

    Diaz, Patricia I.; Abusleme, Loreto; Hong, Bo-Young; Amanda K. Dupuy; Linda D Strausbaugh

    2014-01-01

    Background and objective: The advent of next-generation sequencing has significantly facilitated characterization of the oral microbiome. Despite great efforts in streamlining the processes of sequencing and data curation, upstream steps required for amplicon library generation could still influence 16S rRNA gene-based microbial profiles. Among upstream processes, DNA extraction is a critical step that could represent a great source of bias. Accounting for bias introduced by extraction proced...

  7. Influence of DNA extraction on oral microbial profiles obtained via 16S rRNA gene sequencing

    Directory of Open Access Journals (Sweden)

    Loreto Abusleme

    2014-04-01

    Full Text Available Background and objective: The advent of next-generation sequencing has significantly facilitated characterization of the oral microbiome. Despite great efforts in streamlining the processes of sequencing and data curation, upstream steps required for amplicon library generation could still influence 16S rRNA gene-based microbial profiles. Among upstream processes, DNA extraction is a critical step that could represent a great source of bias. Accounting for bias introduced by extraction procedures is important when comparing studies that use different methods. Identifying the method that best portrays communities is also desirable. Accordingly, the aim of this study was to evaluate bias introduced by different DNA extraction procedures on oral microbiome profiles. Design: Four DNA extraction methods were tested on mock communities consisting of seven representative oral bacteria. Additionally, supragingival plaque samples were collected from seven individuals and divided equally to test two commonly used DNA extraction procedures. Amplicon libraries of the 16S rRNA gene were generated and sequenced via 454-pyrosequencing. Results: Evaluation of mock communities revealed that DNA yield and bacterial species representation varied with DNA extraction methods. Despite producing the lowest yield of DNA, a method that included bead beating was the only protocol capable of detecting all seven species in the mock community. Comparison of the performance of two commonly used methods (crude lysis and a chemical/enzymatic lysis+column-based DNA isolation on plaque samples showed no effect of extraction protocols on taxa prevalence but global community structure and relative abundance of individual taxa were affected. At the phylum level, the latter method improved the recovery of Actinobacteria, Bacteroidetes, and Spirochaetes over crude lysis. Conclusion: DNA extraction distorts microbial profiles in simulated and clinical oral samples, reinforcing the

  8. Sequence analysis of 16S rDNA derived from a high yield lipase strain%一株高产脂肪酶产生菌16S rDNA的序列分析

    Institute of Scientific and Technical Information of China (English)

    孙新城; 马淑玲; 张玲丽; 张浩; 景建洲

    2012-01-01

    [目的]对分离获得的高产脂肪酶菌株进行鉴定,为其改造和更好利用奠定基础.[方法]对从食堂下水道中分离获得的一株高效产脂肪酶细菌(JLΠ-4)进行培养,提取其基因组DNA.设计16S rDNA通用引物,扩增16S rDNA基因片段,并连接到pUC19-T载体上,转化大肠杆菌DH5X,经PCR鉴定的阳性克隆摇菌培养后测序.[结果]提取获得较高质量的基因组DNA,扩增获得新分离菌株16S rDNA基因片段,长度为1528 bp,BLAST相似性比对分析结果表明,其与伯克霍尔德氏菌16S rDNA序列相似性达97%,是一株与伯克霍尔德氏菌最近的革兰氏阴性菌.[结论]初步将高产脂肪酶细菌JTΠ-4鉴定为唐菖蒲伯克霍尔德菌.%[Objective]The present study was conducted to identify the separated high yield lipase strain to provide theoretical research references and to enhance the high yield lipase strain's transformation and application. [Method]A strain of bacterium with high yield lipase JLIT-4 was isolated from the sewage of a canteen, then its genomic DNA was extracted. The gene fragments of 16S rDNA were amplified using 16S rDNA universal primers and connected to pUC19-T vector; the fragments are then transformed into E. Coli DH5X. The positive clones identified by the PCR method were cultured and sequenced. [Result]Quality genome DNA was successfully extracted. The 16S rDNA gene fragments of newly isolated strain were amplified with the length of 1528 bp. According to comparison analysis of BLAST, 16S rDNA sequence similarity between the strains and Burkholderia(DQ355168) were 97%, so the lipase producing strains were identified as gram-negative bacteria that were most similar to the structures of Burkholderia. [ Conclusion ]The high-yield lipase JLΠ-4 was primarily identified as Burkholderia gladioli.

  9. 16S ribosomal RNA pseudouridine synthase RsuA of Escherichia coli: deletion, mutation of the conserved Asp102 residue, and sequence comparison among all other pseudouridine synthases.

    Science.gov (United States)

    Conrad, J; Niu, L; Rudd, K; Lane, B G; Ofengand, J

    1999-06-01

    The gene for RsuA, the pseudouridine synthase that converts U516 to pseudouridine in 16S ribosomal RNA of Escherichia coli, has been deleted in strains MG1655 and BL21/DE3. Deletion of this gene resulted in the specific loss of pseudouridine516 in both cell lines, and replacement of the gene in trans on a plasmid restored the pseudouridine. Therefore, rsuA is the only gene in E. coli with the ability to produce a protein capable of forming pseudouridine516. There was no effect on the growth rate of rsuA- MG1655 either in rich or minimal medium at either 24, 37, or 42 degrees C. Plasmid rescue of the BL21/DE3 rsuA- strain using pET15b containing an rsuA gene with aspartate102 replaced by asparagine or threonine demonstrated that neither mutant was active in vivo. This result supports a role for this aspartate, located in a unique GRLD sequence in this gene, at the catalytic center of the synthase. Induction of wild-type and the two mutant synthases in strain BL21/DE3 from genes in pET15b yielded a strong overexpression of all three proteins in approximately equal amounts showing that the mutations did not affect production of the protein in vivo and thus that the lack of activity was not due to a failure to produce a gene product. Aspartate102 is found in a conserved motif present in many pseudouridine synthases. The conservation and distribution of this motif in nature was assessed.

  10. Phylogenetic analysis of 16S mitochondrial DNA data in sloths and anteaters

    Directory of Open Access Journals (Sweden)

    Maria Claudene Barros

    2003-01-01

    Full Text Available We sequenced part of the 16S rRNA mitochondrial gene in 17 extant taxa of Pilosa (sloths and anteaters and used these sequences along with GenBank sequences of both extant and extinct sloths to perform phylogenetic analysis based on parsimony, maximum-likelihood and Bayesian methods. By increasing the taxa density for anteaters and sloths we were able to clarify some points of the Pilosa phylogenetic tree. Our mitochondrial 16S results show Bradypodidae as a monophyletic and robustly supported clade in all the analysis. However, the Pleistocene fossil Mylodon darwinii does not group significantly to either Bradypodidae or Megalonychidae which indicates that trichotomy best represents the relationship between the families Mylodontidae, Bradypodidae and Megalonychidae. Divergence times also allowed us to discuss the taxonomic status of Cyclopes and the three species of three-toed sloths, Bradypus tridactylus, Bradypus variegatus and Bradypus torquatus. In the Bradypodidae the split between Bradypus torquatus and the proto-Bradypus tridactylus / B. variegatus was estimated as about 7.7 million years ago (MYA, while in the Myrmecophagidae the first offshoot was Cyclopes at about 31.8 MYA followed by the split between Myrmecophaga and Tamandua at 12.9 MYA. We estimate the split between sloths and anteaters to have occurred at about 37 MYA.

  11. The location of protein S8 and surrounding elements of 16S rRNA in the 70S ribosome from combined use of directed hydroxyl radical probing and X-ray crystallography.

    Science.gov (United States)

    Lancaster, L; Culver, G M; Yusupova, G Z; Cate, J H; Yusupov, M M; Noller, H F

    2000-05-01

    Ribosomal protein S8, which is essential for the assembly of the central domain of 16S rRNA, is one of the most thoroughly studied RNA-binding proteins. To map its surrounding RNA in the ribosome, we carried out directed hydroxyl radical probing of 16S rRNA using Fe(II) tethered to nine different positions on the surface of protein S8 in 70S ribosomes. Hydroxyl radical-induced cleavage was observed near the classical S8-binding site in the 620 stem, and flanking the other S8-footprinted regions of the central domain at the three-helix junction near position 650 and the 825 and 860 stems. In addition, cleavage near the 5' terminus of 16S rRNA, in the 300 region of its 5' domain, and in the 1070 region of its 3'-major domain provide information about the proximity to S8 of RNA elements not directly involved in its binding. These data, along with previous footprinting and crosslinking results, allowed positioning of protein S8 and its surrounding RNA elements in a 7.8-A map of the Thermus thermophilus 70S ribosome. The resulting model is in close agreement with the extensive body of data from previous studies using protein-protein and protein-RNA crosslinking, chemical and enzymatic footprinting, and genetics.

  12. Bacterial diversity of soil under eucalyptus assessed by 16S rDNA sequencing analysis Diversidade bacteriana de solo sob eucaliptos obtida por seqüenciamento do 16S rDNA

    Directory of Open Access Journals (Sweden)

    Érico Leandro da Silveira

    2006-10-01

    Full Text Available Studies on the impact of Eucalyptus spp. on Brazilian soils have focused on soil chemical properties and isolating interesting microbial organisms. Few studies have focused on microbial diversity and ecology in Brazil due to limited coverage of traditional cultivation and isolation methods. Molecular microbial ecology methods based on PCR amplified 16S rDNA have enriched the knowledge of soils microbial biodiversity. The objective of this work was to compare and estimate the bacterial diversity of sympatric communities within soils from two areas, a native forest (NFA and an eucalyptus arboretum (EAA. PCR primers, whose target soil metagenomic 16S rDNA were used to amplify soil DNA, were cloned using pGEM-T and sequenced to determine bacterial diversity. From the NFA soil 134 clones were analyzed, while 116 clones were analyzed from the EAA soil samples. The sequences were compared with those online at the GenBank. Phylogenetic analyses revealed differences between the soil types and high diversity in both communities. Soil from the Eucalyptus spp. arboretum was found to have a greater bacterial diversity than the soil investigated from the native forest area.Estudos sobre impacto do Eucalyptus spp. em solos brasileiros têm focalizado propriedades químicas do solo e isolamento de microrganismos de interesse. No Brasil há pouco enfoque em ecologia e diversidade microbiana, devido às limitações dos métodos tradicionais de cultivo e isolamento. A utilização de métodos moleculares no estudo da ecologia microbiana baseados na amplificação por PCR do 16S rDNA têm enriquecido o conhecimento da biodiversidade microbiana dos solos. O objetivo deste trabalho foi comparar e estimar a diversidade bacteriana de comunidades simpátricas em solos de duas áreas: uma floresta nativa (NFA e outra adjacente com arboreto de eucaliptos (EAA. Oligonucleotídeos iniciadores foram utilizados para amplificar o 16S rDNA metagenômico do solo, o qual foi

  13. Rapid detection of the mutations of neisseria gonorrhoeae 16S rRNA gene using DNA chip%DNA芯片快速检测淋球菌16S rRNA基因突变

    Institute of Scientific and Technical Information of China (English)

    周文明; 杨森; 赵建龙; 曹慧敏; 张学军

    2012-01-01

    目的 探讨新研制的DNA芯片应用于快速检测淋球菌16S rRNA 基因突变的临床应用价值.方法 根据淋球菌16SrRNA 基因的序列信息设计探针并制作DNA芯片,PCR扩增并荧光标记包含16S rRNA 基因突变的目的 DNA片段,与芯片杂交,同时以测序法为对照.结果 87份泌尿生殖道拭子均可被DNA芯片检测,同时检测发现有1株淋球菌16S rRNA基因突变(2709 C→T),与测序结果 一致.结论 DNA芯片检测淋球菌16SrRNA基因突变具有快速、高特异性和高灵敏度,可以应用于对大观霉素的耐药性临床检测.%To develop a new method, DNA chip, for rapid detection the mutations of neisseria gonorrhoeae 16S rRNA gene. Methods Probe were design according to the sequence of neisseria gonorrhoeae 16S rRNA genes, then DNA chip was made. DNA fragment which contains 16S rRNA gene mutation was amplified by PCR technique, labeled with cy5 fluorescence, and then hybridized with DNA chip. Results of DNA sequencing were used as the control. Results All of urogenital swab specimens were detected by DNA chip. We found one specimen which had mutation in gene 16S rRNA( 2709 C->T), which was consistency between the DNA chip and DNA sequencing. Conclusion DNA chip is a rapid technique with high sensitivity and specificity for the detection of mutations of neisseria gonorrhoeae 16SrRNA gene. This method can be used for detection of spectinomycin resistance in clinical practice.

  14. 'Candidatus Phytoplasmas pruni', a novel taxon associated with X-disease of stone fruits, Prunus spp.: multilocus characterization based on 16S rRNA, secY, and ribosomal protein genes

    Science.gov (United States)

    X-disease is one of the most serious diseases known in peach (Prunus persica). Based on RFLP analysis of 16S rRNA gene sequences, peach X-disease phytoplasma strains from eastern and western United States and eastern Canada were classified in 16S rDNA RFLP group 16SrIII, subgroup A. Phylogenetic a...

  15. Isolation and 16S DNA characterization of soil microorganisms from tropical soils capable of utilizing the herbicides hexazinone and tebuthiuron.

    Science.gov (United States)

    Mostafa, Fadwa I Y; Helling, Charles S

    2003-11-01

    Six non-fermentative bacteria were isolated from Colombian (South America) and Hawaiian (USA) soils after enrichment with minimal medium supplemented with two herbicides, hexazinone (Hex) and tebuthiuron (Teb). Microscopic examination and physiological tests were followed by partial 16S DNA sequence analysis, using the first 527 bp of the 16S rRNA gene for bacterial identification. The isolated microorganisms (and in brackets, the herbicide that each degraded) were identified as: from Colombia. Methylobacterium organophilum [Teb], Paenibacillus pabuli [Teb], and Micrmbacterium foliorum [Hex]; and from Hawaii, Methylobacterium radiotolerans [Teb], Paenibacillus illinoisensis [Hex], and Rhodococcus equi [Hex]. The findings further explain how these herbicides, which have potential for illicit coca (Erythroxylum sp.) control, dissipate following their application to tropical soils. PMID:14649709

  16. Phylogenetic relationships of five species of Dorippinae (Crustacea, Decapoda) revealed by 16S rDNA sequence analysis

    Institute of Scientific and Technical Information of China (English)

    FANYu; LIXinzheng; SONGLinsheng; CAIZhonghua

    2004-01-01

    A molecular phylogeny is presented for the subfamily Dorippinae (including 9 individuals, representing 5 species and 4 genera), based on the sequence data from 16S rRNA gene. Two-cluster test between lineages in these phylogenetic trees has been performed. On the basis of rate constancy, the rate of nucleotide substitutions of 16S rDNA sequence data is estimated as 0.27% per million years. The analysis strongly supports the recognition of the Dorippinae as a monophyletic subfamily. Phylogenetic tree indicates that the subfamily Dorippinae is divided into two main clades, and genus Dorippe appears basal in the subfamily, diverging from other species 36.6 Ma ago. It is also clear that the Heikea is closely related to the genus Neodorippe. The divergence time between them is 15.8 Ma.

  17. Metagenomic Analysis of Slovak Bryndza Cheese Using Next-Generation 16S rDNA Amplicon Sequencing

    Directory of Open Access Journals (Sweden)

    Planý Matej

    2016-06-01

    Full Text Available Knowledge about diversity and taxonomic structure of the microbial population present in traditional fermented foods plays a key role in starter culture selection, safety improvement and quality enhancement of the end product. Aim of this study was to investigate microbial consortia composition in Slovak bryndza cheese. For this purpose, we used culture-independent approach based on 16S rDNA amplicon sequencing using next generation sequencing platform. Results obtained by the analysis of three commercial (produced on industrial scale in winter season and one traditional (artisanal, most valued, produced in May Slovak bryndza cheese sample were compared. A diverse prokaryotic microflora composed mostly of the genera Lactococcus, Streptococcus, Lactobacillus, and Enterococcus was identified. Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris were the dominant taxons in all tested samples. Second most abundant species, detected in all bryndza cheeses, were Lactococcus fujiensis and Lactococcus taiwanensis, independently by two different approaches, using different reference 16S rRNA genes databases (Greengenes and NCBI respectively. They have been detected in bryndza cheese samples in substantial amount for the first time. The narrowest microbial diversity was observed in a sample made with a starter culture from pasteurised milk. Metagenomic analysis by high-throughput sequencing using 16S rRNA genes seems to be a powerful tool for studying the structure of the microbial population in cheeses.

  18. Comparison of 16S rDNA-PCR Amplification and Culture of Cerebrospinal Fluid for Diagnosis of Bacterial Meningitis

    Directory of Open Access Journals (Sweden)

    Farshad Foroughi

    2010-12-01

    Full Text Available Objective:Early and accurate diagnosis of bacterial meningitis is of critical concern. Optimum and rapid laboratory facilities are not routinely available for detecting the etiologic agents of meningitis. The objective of this study was to compare polymerase chain reaction (PCR assay with culture for detection of bacteria in central nervous system (CNS samples from patients suspected to have meningitis. Methods: One-hundred CSF samples were obtained and divided into two parts. One part of samples was used for standard bacterial culture and gram staining. The remaining was used for DNA extraction. PCR assay was performed with universal primers for 16S rDNA gene of bacteria. Performance characteristics of the test were determined. Findings:The PCR method was able to detect bacteria in all 36 culture-positive and in 38 of 64 culture-negative cases showing sensitivity and specificity of 100% and 40.6% respectively. Positive predictive value was 48.6% and negative predictive value 100%, however, Kappa coefficient showed the correlation of the 2 methods to be at 0.33. Conclusion:There are advantages and disadvantages in performance characteristics of the conventional CSF culture and universal CSF 16S rDNA PCR. Therefore, it is recommended to use both methods in clinical practice, particularly in suspicious contaminated samples, with presumable presence of fastidious or slow growing bacteria because of antibiotic consumption.

  19. Molecular and functional diversity of PGPR fluorescent Pseudomonads based on 16S rDNA-RFLP and RAPD markers.

    Science.gov (United States)

    Singh, Bhim Pratap

    2015-09-01

    The genetic and functional diversity of plant growth promoting rhizobacterial (PGPR) fluorescent pseudomonads associated with chickpea (Cicer arietinum L.) rhizosphere was analyzed. In total, 34 isolates along with two reference isolates were screened for various plant growth promoting traits (phosphorous solubilization, ACC deaminase, HCN, IAA and siderophore productions) and antagonist activity against four fungal phytopathogens and three bacterial pathogens. Most of the isolates, that showed PGPR activity, also showed antagonistic activity against all the three fungal pathogens. The genetic relationship was assessed by using random amplification of polymorphic DNA (RAPD) and PCR-restriction fragment length polymorphism (16S rDNA-RFLP). Relationship between both the markers was analyzed based on mantel test and a negative correlation was observed. The study concluded that PGPR traits appeared to be strain specific rather than specific to any phylogenetic group. The study also reported that 16S rDNA based profiling differentiated PGPR fluorescent Pseudomonas on the basis of location rather than biological trait. RAPD profiling could be useful to differentiate among the closely related isolates. The genetic and functional diversity of fluorescent pseudomonads, associated with the chickpea rhizosphere, has useful ecological role and potential utilization in sustainable agriculture.

  20. 16S and 23S plastid rDNA phylogenies of Prototheca species and their auxanographic phenotypes1

    Science.gov (United States)

    Ewing, Aren; Brubaker, Shane; Somanchi, Aravind; Yu, Esther; Rudenko, George; Reyes, Nina; Espina, Karen; Grossman, Arthur; Franklin, Scott

    2014-01-01

    Because algae have become more accepted as sources of human nutrition, phylogenetic analysis can help resolve the taxonomy of taxa that have not been well studied. This can help establish algal evolutionary relationships. Here, we compare Auxenochlorella protothecoides and 23 strains of Prototheca based on their complete 16S and partial 23S plastid rDNA sequences along with nutrient utilization (auxanographic) profiles. These data demonstrate that some of the species groupings are not in agreement with the molecular phylogenetic analyses and that auxanographic profiles are poor predictors of phylogenetic relationships. PMID:25937672

  1. 16s-23S rDNA: polymorphisms and their use for detection and identification of Xylella fastidiosa strains 16S-23S rDNA: polimorfismos e sua aplicação na detecção e identificação de linhagens de Xylella fastidiosa

    Directory of Open Access Journals (Sweden)

    Juliana Camargo Martinati

    2007-03-01

    Full Text Available Strains of Xylella fastidiosa from several hosts (coffee, citrus, grape, almond, oleander, peach, plum, etc. were characterized by analyzing the content of the nucleotide sequences of 16S-23S rDNA (coding for a small subunit ribosomal RNA spacer region (ITS. Current methods for sequencing the ITS region yields partial sequences that do not contribute with significant information. According to this fact, new primers have been designed in order to obtain a complete sequence and facilitate the sequencing. The complete 16S-23S sequences from 08 strains were amplified through PCR using the primers designed in our lab. The 16S-23S sequences obtained were compared with 52 others sequences entries in GenBank database. The results revealed a higher level of variation than that found in 16S gene sequences, with similarity values ranging from 0.79-1.00. The dendogram based on similarity data revealed 5 main groups. This spacer sequence contains two genes for tRNA (tRNAala and tRNAile. The sequence analysis of the tRNA content showed a conserved region with a few differences in the nucleotide composition.Linhagens de Xylella fastidiosa de diferentes hospedeiros (café, uva, amêndoa, ameixa, etc. foram caracterizados analisando as sequências de nucleotídeos do espaço intergênico 16S-23S (ITS. Os métodos atuais para o sequenciamento da região ITS produzem fragmentos parciais das sequências que não contribuem com informações significantes. Em vista disso, novos primers foram desenhados a fim de obter uma sequência completa e facilitar o sequenciamento. A sequencia completa da região ITS de 08 linhagens de X. Fastidiosa foram amplificadas via PCR, sequenciadas e comparadas com outras 52 sequencias depositadas no GenBank. Os resultados revelaram um alto nível de variação sendo maior que os níveis encontrados quando se utiliza o gene 16S para este tipo de análise, com valores variando entre 0.79 a 1.00. O dendograma baseado em dados de

  2. Identification of Pheretima aspergillum by CO Ⅰ and 16S rRNA with DNA Molecular Marker Methods%基于COⅠ与16S rRNA基因对广地龙的DNA分子鉴定研究

    Institute of Scientific and Technical Information of China (English)

    韦健红; 李薇; 吴文如; 喻良文

    2012-01-01

    OBJECTIVE: To establish a rapid, accurate and standardized DNA molecular marker method for the identification of Pheretima aspergillum. METHODS: The CO Ⅰ and 16S rRNA gene sequences of P. aspergillum from 5 different populations were determined using CodonCode Aligner sequence assembly. In addition, the CO Ⅰ and 16S rRNA gene sequences of P. aspergillum were downloaded from GenBank, and intraspecific and interspecific K2P genetic distance between P. aspergillum and counterfeit were calculated with MEGA 4.1 to construct NJ and MP phylogenetic tree. RESULTS: The variation sites and information sites of CO Ⅰ were higher than those of 16S rRNA. There were no insertions and deletions of CO Ⅰ , and there were 4 insertions and deletions of 16S rRNA. The interspecific genetic distances of CO Ⅰ and 16S rRNA sequences were significantly greater than intraspecific ones, and CO Ⅰ and 16S rRNA gene can be identified from the other earthworm species. CONCLUSION: The CO I and 16S rRNA gene can provide reference for the identification of the animal Chinese medicine at the molecular level, and accumulate information for DNA barcode of animal Chinese medicine.%目的:建立一种快速、准确和标准化的广地龙DNA分子标记鉴别方法.方法:测定了5个不同居群广地龙的线粒体细胞色素酶亚单位(CO)Ⅰ和16S rRNA基因序列,采用CodonCode Aligner进行序列拼接,通过下载GenBank地龙原动物的CO Ⅰ与16S rRNA序列,采用MEGA 4.1计算广地龙及其伪品地龙的种内、种间的K2P遗传距离,并基于K2P模型构建NJ和MP树.结果:COⅠ变异位点、信息位点均高于16S rRNA,CO Ⅰ基因无插入和缺失,16S rRNA存在4个插入和缺失.CO Ⅰ和16S rRNA序列种间遗传距离均明显大于种内,CO Ⅰ和16S rRNA基因均能将广地龙从其他地龙或蚯蚓物种鉴别开来.结论:获得的广地龙CO Ⅰ和16S rRNA序列可为动物性中药材地龙的分子水平鉴定提供参考,为动物性中药材DNA条

  3. A comparison of two real-time polymerase chain reaction assays using hybridization probes targeting either 16S ribosomal RNA or a subsurface lipoprotein gene for detecting leptospires in canine urine.

    Science.gov (United States)

    Gentilini, Fabio; Zanoni, Renato Giulio; Zambon, Elisa; Turba, Maria Elena

    2015-11-01

    Leptospires are excreted in the urine of infected animals, and the prompt detection of leptospiral DNA using polymerase chain reaction (PCR) is increasingly being used. However, contradictory data has emerged concerning the diagnostic accuracy of the most popular PCR assays that target either the 16S ribosomal RNA (rrs) or the subsurface lipoprotein (LipL32) genes. In order to clarify the effect of the gene target, a novel hydrolysis probe-based, quantitative real-time PCR (qPCR) assay targeting the LipL32 gene was developed, validated, and then compared directly to the previously described rrs hydrolysis probe-based qPCR using a convenience collection of canine urine samples. The novel LipL32 qPCR assay was linear from 5.9 × 10(6) to 59 genome equivalents per reaction. Both the LipL32 and the rrs qPCR assays showed a limit of detection of 10 target copies per reaction indicating an approximately equivalent analytical sensitivity. Both assays amplified all 20 pathogenic leptospiral strains tested but did not amplify a representative collection of bacteria commonly found in voided canine urine. When the field samples were assayed, 1 and 5 out of 184 samples yielded an amplification signal in the LipL32 and rrs assays, respectively. Nevertheless, when the limit of detection was considered as the cutoff for interpreting findings, the 4 discordant cases were judged as negative. In conclusion, our study confirmed that both LipL32 and rrs are suitable targets for qPCR for the detection of leptospiral DNA in canine urine. However, the rrs target requires the mandatory use of a cutoff value in order to correctly interpret spurious amplifications.

  4. Identification of signature and primers specific to genus Pseudomonas using mismatched patterns of 16S rDNA sequences

    Directory of Open Access Journals (Sweden)

    Kapley A

    2003-05-01

    Full Text Available Abstract Background Pseudomonas, a soil bacterium, has been observed as a dominant genus that survives in different habitats with wide hostile conditions. We had a basic assumption that the species level variation in 16S rDNA sequences of a bacterial genus is mainly due to substitutions rather than insertion or deletion of bases. Keeping this in view, the aim was to identify a region of 16S rDNA sequence and within that focus on substitution prone stretches indicating species level variation and to derive patterns from these stretches that are specific to the genus. Results Repeating elements that are highly conserved across different species of Pseudomonas were considered as guiding markers to locate a region within the 16S gene. Four repeating patterns showing more than 80% consistency across fifty different species of Pseudomonas were identified. The sub-sequences between the repeating patterns yielded a continuous region of 495 bases. The sub-sequences after alignment and using Shanon's entropy measure yielded a consensus pattern. A stretch of 24 base positions in this region, showing maximum variations across the sampled sequences was focused for possible genus specific patterns. Nine patterns in this stretch showed nearly 70% specificity to the target genus. These patterns were further used to obtain a signature that is highly specific to Pseudomonas. The signature region was used to design PCR primers, which yielded a PCR product of 150 bp whose specificity was validated through a sample experiment. Conclusions The developed approach was successfully applied to genus Pseudomonas. It could be tried in other bacterial genera to obtain respective signature patterns and thereby PCR primers, for their rapid tracking in the environmental samples.

  5. Sequencing 16S rRNA gene fragments using the PacBio SMRT DNA sequencing system.

    Science.gov (United States)

    Schloss, Patrick D; Jenior, Matthew L; Koumpouras, Charles C; Westcott, Sarah L; Highlander, Sarah K

    2016-01-01

    Over the past 10 years, microbial ecologists have largely abandoned sequencing 16S rRNA genes by the Sanger sequencing method and have instead adopted highly parallelized sequencing platforms. These new platforms, such as 454 and Illumina's MiSeq, have allowed researchers to obtain millions of high quality but short sequences. The result of the added sequencing depth has been significant improvements in experimental design. The tradeoff has been the decline in the number of full-length reference sequences that are deposited into databases. To overcome this problem, we tested the ability of the PacBio Single Molecule, Real-Time (SMRT) DNA sequencing platform to generate sequence reads from the 16S rRNA gene. We generated sequencing data from the V4, V3-V5, V1-V3, V1-V5, V1-V6, and V1-V9 variable regions from within the 16S rRNA gene using DNA from a synthetic mock community and natural samples collected from human feces, mouse feces, and soil. The mock community allowed us to assess the actual sequencing error rate and how that error rate changed when different curation methods were applied. We developed a simple method based on sequence characteristics and quality scores to reduce the observed error rate for the V1-V9 region from 0.69 to 0.027%. This error rate is comparable to what has been observed for the shorter reads generated by 454 and Illumina's MiSeq sequencing platforms. Although the per base sequencing cost is still significantly more than that of MiSeq, the prospect of supplementing reference databases with full-length sequences from organisms below the limit of detection from the Sanger approach is exciting.

  6. Affinity of ribosomal protein S8 from mesophilic and (hyper)thermophilic archaea and bacteria for 16S rRNA correlates with the growth temperatures of the organisms.

    Science.gov (United States)

    Gruber, Thomas; Köhrer, Caroline; Lung, Birgit; Shcherbakov, Dmitri; Piendl, Wolfgang

    2003-08-14

    The ribosomal protein S8 plays a pivotal role in the assembly of the 30S ribosomal subunit. Using filter binding assays, S8 proteins from mesophilic, and (hyper)thermophilic species of the archaeal genus Methanococcus and from the bacteria Escherichia coli and Thermus thermophilus were tested for their affinity to their specific 16S rRNA target site. S8 proteins from hyperthermophiles exhibit a 100-fold and S8 from thermophiles exhibit a 10-fold higher affinity than their mesophilic counterparts. Thus, there is a striking correlation of affinity of S8 proteins for their specific RNA binding site and the optimal growth temperatures of the respective organisms. The stability of individual rRNA-protein complexes might modulate the stability of the ribosome, providing a maximum of thermostability and flexibility at the growth temperature of the organism.

  7. Identification of Thiobacillus ferrooxidans strains based on restriction fragment length polymorphism analysis of 16S rDNA.

    Science.gov (United States)

    Kamimura, K; Wakai, S; Sugio, T

    2001-01-01

    The 16S rDNA sequences from ten strains of Thiobacillus ferrooxidans were amplified by PCR. The products were compared by performing restriction fragment length polymorphism (RFLP) analysis with restriction endonucleases Alu I, Hap II, Hha I, and Hae III. The RFLP patterns revealed that T. ferrooxidans could be distinguished from other iron- or sulphur-oxidizing bacteria such as T. thiooxidans NB1-3, T. caldus GO-1, Leptospirillum ferrooxidans and the marine iron-oxidizing bacterium strain KU2-11. The RFLP patterns obtained with Alu I, Hap II, and Hae III were the same for nine strains of T. ferrooxidans except for strain ATCC 13661. The RFLP patterns for strains NASF-1 and ATCC 13661 with Hha I were distinct from those for other T. ferrooxidans strains. The 16S rDNA sequence of T. ferrooxidans NASF-1 possessed an additional restriction site for Hha I. These results show that iron-oxidizing bacteria isolated from natural environments were rapidly identified as T. ferrooxidans by the method combining RFLP analysis with physiological analysis. PMID:11414499

  8. Rapid identification and classification of bacteria by 16S rDNA restriction fragment melting curve analyses (RFMCA).

    Science.gov (United States)

    Rudi, Knut; Kleiberg, Gro H; Heiberg, Ragnhild; Rosnes, Jan T

    2007-08-01

    The aim of this work was to evaluate restriction fragment melting curve analyses (RFMCA) as a novel approach for rapid classification of bacteria during food production. RFMCA was evaluated for bacteria isolated from sous vide food products, and raw materials used for sous vide production. We identified four major bacterial groups in the material analysed (cluster I-Streptococcus, cluster II-Carnobacterium/Bacillus, cluster III-Staphylococcus and cluster IV-Actinomycetales). The accuracy of RFMCA was evaluated by comparison with 16S rDNA sequencing. The strains satisfying the RFMCA quality filtering criteria (73%, n=57), with both 16S rDNA sequence information and RFMCA data (n=45) gave identical group assignments with the two methods. RFMCA enabled rapid and accurate classification of bacteria that is database compatible. Potential application of RFMCA in the food or pharmaceutical industry will include development of classification models for the bacteria expected in a given product, and then to build an RFMCA database as a part of the product quality control. PMID:17367680

  9. Genetic diversity of Helicobacter pylori indexed with respect to clinical symptomatology, using a 16S rRNA and a species-specific DNA probe.

    Science.gov (United States)

    Desai, M; Linton, D; Owen, R J; Cameron, H; Stanley, J

    1993-12-01

    DNA probes are described which identify group and fingerprint strains of the human gastric pathogen Helicobacter pylori, on the basis of well-defined band homologies. A 544 bp internal fragment of the 16S ribosomal RNA gene was generated by polymerase chain reaction (PCR) with primers derived from the Escherichia coli rRNA gene sequence. In genomic Southern blots this probe detected restriction site variation around these loci, generating simple but strain-specific molecular fingerprints. A small conserved chromosomal fragment of 1.2 kbp, Hps, species-specific for H. pylori, was obtained by cloning random HindIII fragments into pUC19. It was useful for dot-blot identification, and also separated isolates into one major and two minor groups. When results for these two probes were combined, a baseline characterization of genotype was obtained. A band-matching database of molecular fingerprints for the type strain and 63 clinical isolates of H. pylori from asymptomatic, ulcer and gastritis contexts is presented. No significant association between the genotypes at this level of definition and the associated clinical symptomatology of the isolates was detected.

  10. 利用线粒体16S rRNA 基因全序列分析直翅目主要类群的系统发生关系%Phylogenetic relationships among Orthoptera insect groups based on complete sequences of 16S ribosomal RNA

    Institute of Scientific and Technical Information of China (English)

    崔爱明; 黄原

    2012-01-01

    In order to reconstruct a robust phylogenetic relationship among major groups of Orthoptera and to explore the phylogenetic utility and performance of 16S Ribosomal RNA gene, complete sequences of 16S Ribosomal RNA were sequenced from 18 species in 9 families and 4 superfamilies of Orthoptera, and analyzed with other 40 species that have been completely sequenced. The result showed that the average length of 16S Ribosomal RNA was 1 310 bp. The positions of Tridactuloidea and Gryllotalpidae in Orthoptera were uncertain based on the 16S rRNA data, and the phylogenetic relationships of other major groups in Orthoptera were rather robust. Except for Oedipodidae and Gomphoceridae, Acrididae, Catantopidae, and Arcypteridae in Xia's taxonomic system were not monophyletic groups, and the genetic distances among the five groups were small. This indicates that the five families should be combined into one family. The genetic distances among Pamphagidae, Chrotogonidae, and Pyigomorphidae were also small. The loops of 16S rRNA gene could provide more information than stems when they were used for phylogenetic analysis. Complete sequence of 16S rRNA gene can be used to reconstruct robust phylogenetic relationship at the taxonomic category of species, genera, and suborder in Orthop-tera, but lack of resolution at family and superfamily levels.%为了构建稳健的直翅目主要类群间的系统发生关系并探讨16S rRNA 基因序列在构建直翅目昆虫不同分类阶元系统发生关系时的可行性、功效以及性能,文章测定了直翅目4 总科9 科18 种昆虫的16S rRNA 基因全序列,联合已知该基因全序列的其他40 种昆虫,构建了直翅目主要类群之间的系统发生关系,并分析了16S rRNA 基因全序列的系统发生性能和功效.结果表明,直翅目昆虫的16S rRNA 基因全长平均为1 310 bp; 除生活方式特化的蚤蝼总科和蝼蛄总科的地位无法确定外,直翅目其他主要类群

  11. Species identification of meat products based on mtDNA 16S rRNA gene sequencing%应用mtDNA16S rRNA基因测序鉴定肉产品种属

    Institute of Scientific and Technical Information of China (English)

    艾斯卡尔·买买提; 马合木提·哈力克; 日沙来提·吐尔地; 古丽茹合萨·艾海提

    2011-01-01

    Objective Applied mtDNA 16S rRNA gene sequencing method performed species identification of meat products. Methods 15 unknown animal muscle samples were given for inspection by related authorities, pork, beef and lamb were bought and used as a control. Extract DNA by conventional phenol-chloroform method, amplified mtDNA 16S rRNA gene by using the general primer and the specific primers respectively, products were examined by 1. 5% agarose gel electrophoresis. Amplified sequences were sequenced by Shanghai Bio-Engineering Company and then compared the identities through sequencing and BLAST aligning. Results All PCR products from 15 received samples amplified with general primer were showed positive band; neither one of them had positive band while used the sheep specific primer; while used specific primer of pig and bovine 14 and 1 of testing samples had amplified positive band respectively. The identity of them with pork and beef were 96% ~ 100% respectively while sequenced and BLAST aligned. Conclusion Among the 15 unknown meat products 14were pork and one was beef.%目的 应用mtDNA 16S rRNA基因测序方法进行肉产品种属鉴定.方法 15份有关部门送检的未知动物肌肉样本,3份市购猪、牛和羊的肌肉为对照样本.常规酚-氯仿法提取模板DNA,分别用通用引物和特异性引物扩增mtDNA的16S rRNA基因片段,产物用1.5%琼脂糖电泳检测,扩增的基因片段由上海生物工程公司进行序列测定及基因库同源性匹配查询.结果 经通用引物扩增15份未知样本,均检测出阳性条带;用羊特异性引物扩增,无未知样本检出阳性条带;用猪及牛特异性引物扩增,分别有14份和1份样本检出阳性条带,经测序及同源性查询,分别与猪和牛的同源性为96%~100%.结论 送检未知肉产品样本中14份是猪肉,1份是牛肉.

  12. Revised phylogeny of whales suggested by mitochondrial ribosomal DNA sequences

    OpenAIRE

    Milinkovitch, M.C.; Orti, G.; Meyer, A.

    1993-01-01

    Living cetaceans are subdivided into two highly distinct suborders, Odontoceti (the echolocating toothed whales) and Mysticeti (the filter-feeding baleen whales), which are believed to have had a long independent history. Here we report the determination of DNA sequences from two mitochondrial ribosomal gene segments (930 base pairs per species) for 16 species of cetaceans, a perissodactyl and a sloth, and construct the first phylogeny for whales and dolphins based on explicit cladistic metho...

  13. Detection of novel organisms associated with salpingitis, by use of 16S rDNA polymerase chain reaction.

    Science.gov (United States)

    Hebb, Jennifer K; Cohen, Craig R; Astete, Sabina G; Bukusi, Elizabeth A; Totten, Patricia A

    2004-12-15

    Although Chlamydia trachomatis and Neisseria gonorrhoeae are established causes of salpingitis, the majority of cases have no known etiology. We used broad-range 16S rDNA polymerase chain reaction to identify novel, possibly uncultivable, bacteria associated with salpingitis and identified bacterial 16S sequences in Fallopian-tube specimens from 11 (24%) of 45 consecutive women with laparoscopically confirmed acute salpingitis (the case patients) and from 0 of 44 women seeking tubal ligations (the control subjects) at Kenyatta National Hospital, Nairobi, Kenya. Bacterial phylotypes most closely related to Leptotrichia spp. were detected as the sole phylotypes in 1, and mixed with other bacterial phylotypes in 2, specimens. Novel bacterial phylotypes and those associated with bacterial vaginosis, including Atopobium vaginae, were identified in 3 specimens. N. gonorrhoeae and Streptococcus pyogenes were identified in 2 and 1 specimens, respectively. The finding of novel phylotypes associated with salpingitis has important implications for the etiology, pathogenesis, and treatment of this important reproductive-tract disease syndrome. PMID:15551209

  14. Description of the male, redescription of the female and 16S rDNA sequence of Ixodes aulacodi (Ixodidae).

    Science.gov (United States)

    Chiţimia-Dobler, Lidia; D'Amico, Gianluca; Yao, Patrick Kouassi; Kalmár, Zsuzsa; Gherman, Călin Mircea; Mihalca, Andrei Daniel; Estrada-Peña, Agustin

    2016-04-01

    Ixodes (Afrixodes) aulacodiArthur, 1956 is a poorly known species that has been recorded predominantly in the wet countries of western and central Africa, mainly associated to the greater cane rat Thryonomys swinderianus (Temmink). We herein redescribe the female, describe the male (ascribed to the species from specimens found in copula) and provide the 16S rDNA sequence. We also provide complete illustrations of the adults based on specimens found on greater cane rats in Ivory Coast. Ixodes aulacodi is included in the group of species of the subgenus Afrixodes that have horseshoe shaped anal groove, and which lack auriculae and cornua. The female is easily separated when compared with other species because of a unique combination of characters: All the coxae have internal spurs, coxa II has two external spurs, syncoxae are absent, and trochanters I-III have one spur each. The male has a notched hypostome and lacks syncoxae, auriculae and cornua. PMID:26803353

  15. Differentiation of Acidithiobacillus ferrooxidans and A. thiooxidans strains based on 16S-23S rDNA spacer polymorphism analysis.

    Science.gov (United States)

    Bergamo, Rogério F; Novo, Maria Teresa M; Veríssimo, Ricardo V; Paulino, Luciana C; Stoppe, Nancy C; Sato, Maria Inês Z; Manfio, Gilson P; Prado, Paulo Inácio; Garcia, Oswaldo; Ottoboni, Laura M M

    2004-09-01

    Restriction fragment length polymorphism (RFLP) and sequence analyses of the PCR-amplified 16S-23S rDNA intergenic spacer (ITS) were used for differentiating Acidithiobacillus thiooxidans strains from other related acidithiobacilli, including A. ferrooxidans and A. caldus. RFLP fingerprints obtained with AluI, DdeI, HaeIII, HinfI and MspI enabled the differentiation of all Acidithiobacillus reference strains into species groups. The A. thiooxidans strains investigated (metal mine isolates) yielded identical RFLP patterns to the A. thiooxidans type strain (ATCC 19377(T)), except for strain DAMS, which had a distinct pattern for all enzymes tested. Fourteen A. ferrooxidans mine strains were assigned to 3 RFLP groups, the majority of which were grouped with A. ferrooxidans ATCC 23270(T). The spacer region of one representative strain from each of the RFLP groups obtained was subjected to sequence analysis, in addition to eleven additional A. thiooxidans strains isolated from sediment and water samples, and A. caldus DSM 8584(T). The tRNA(IIe) and tRNA(Ala) genes, present in all strains analyzed, showed high sequence similarity. Phylogenetic analysis of the ITS sequences differentiated all three Acidithiobacillus species. Inter- and infraspecific genetic variations detected were mainly due to the size and sequence polymorphism of the ITS3 region. Mantel tests showed no significant correlation between ITS sequence similarity and the geographical origin of strains. The results showed that the 16S-23S rDNA spacer region is a useful target for the development of molecular-based methods aimed at the detection, rapid differentiation and identification of acidithiobacilli.

  16. Systematics of New World monkeys (Platyrrhini, Primates) based on 16S mitochondrial DNA sequences: a comparative analysis of different weighting methods in cladistic analysis.

    Science.gov (United States)

    Horovitz, I; Meyer, A

    1995-12-01

    In order to investigate the effects of different weighting methods on a phylogeny reconstruction based on DNA sequences and to evaluate the phylogenetic information content of various secondary structures, a fragment of the large ribosomal mitochondrial gene (16S) was sequenced from 13 species of New World monkeys, three species of catarrhines, and Tarsius. The data were analyzed cladistically without weighting characters or changes, and with different weighting methods: a priori differential weights for transitions and transversions, two variants of dynamic weighting for each kind and direction of change, and successive approximations, using both the character consistency index (CI) and the rescaled consistency index (RC). The results were compared with published trees constructed from nuclear sequences of E-globins and morphological characters by different authors. The result of the analysis of the mtDNA data set with successive approximations, using the RC as weighting function, was the closest to the topology on which all molecular and morphological trees concur. Other relationships were unique to this tree. "Loops" were the type of secondary structure that showed maximum variation in sequence length and sites with the lowest character CI and RC. A large number of sites within loops showed high values for these indices, however, which suggests that uniform downweighting of these regions represents a large loss of phylogenetic information. Successive weighting, which assigns a weight for each particular character, seems to be a desirable alternative to this practice. We propose a new variant of dynamic weighting, which we call homoplasy-correcting dynamic weighting, that like dynamic weighting, is applicable to any kind of sequence, coding or noncoding.

  17. Application of bacterial 16S rDNA amplification and sequencing in the classification and identification of bacteria%16S rDNA扩增及测序在细菌鉴定与分类中的应用

    Institute of Scientific and Technical Information of China (English)

    朱诗应; 戚中田

    2013-01-01

    Bacterial 16S rDNA amplification and sequencing is a new tool which has been widely used to identify bacterial species and perform taxonomic studies . The application of this technology for identification of uncultivable bacteria , differentiating species with high DNA sequence similarity and discovering novel bacterial genus and species are introduced in this paper . Future perspective of the method in clinical microbiology laboratories is also discussed .%16S rDNA扩增及测序技术在细菌的鉴定与分类研究中发挥着越来越重要的作用.本文就16S rDNA结构、可变区和保守区部分序列或全序列在临床上细菌鉴定和新细菌识别等方面的研究进展进行综述,并对其在临床实验室中的应用进行展望.

  18. The localization of multiple sites on 16S RNA which are cross-linked to proteins S7 and S8 in Escherichia coli 30S ribosomal subunits by treatment with 2-iminothiolane.

    Science.gov (United States)

    Wower, I; Brimacombe, R

    1983-03-11

    RNA-protein cross-links were introduced into E. coli 30S ribosomal subunits by reaction with 2-iminothiolane followed by a mild ultraviolet irradiation treatment. After removal of non-reacted protein and partial nuclease digestion of the cross-linked 16S RNA-protein moiety, a number of individual cross-linked complexes could be isolated and the sites of attachment of the proteins to the RNA determined. Protein S8 was cross-linked to the RNA at three different positions, within oligo-nucleotides encompassing positions 629-633, 651-654, and (tentatively) 593-597 in the 16S sequence. Protein S7 was cross-linked within two oligonucleotides encompassing positions 1238-1240, and 1377-1378. In addition, a site at position 723-724 was observed, cross-linked to protein S19, S20 or S21.

  19. 16S rRNA Gene Sequence Analysis of Drinking Water Using RNA and DNA Extracts as Targets for Clone Library Development

    Science.gov (United States)

    The bacterial composition of chlorinated drinking water was analyzed using 16S rRNA gene clone libraries derived from DNA extracts of 12 samples and compared to clone libraries previously generated using RNA extracts from the same samples. Phylogenetic analysis of 761 DNA-based ...

  20. Molecular phylogeny of three Moina species based on 16S rDNA gene sequences%三种裸腹溞的16S rDNA序列分析与系统分类探讨

    Institute of Scientific and Technical Information of China (English)

    徐敏; 邓道贵; 张海军; 王文平; 晁秋杰

    2015-01-01

    为了检验已记录的3种裸腹溞(发头裸腹溞(Moina irrasa)、短型裸腹溞(Moina brachiata)、微型裸腹溞(Moina micrura))的系统分类,用试剂盒法分别提取3种裸腹溞的基因组DNA.利用特异性引物,通过PCR扩增了3种裸腹溞的16S rDNA部分序列,并与来自GenBank中每个种类相似度较高的裸腹溞属序列进行分析.结果表明,3种裸腹溞的平均种间相似度为88.7%,碱基中A+T含量均明显高于G+C含量.本研究的发头裸腹溞的16S rDNA序列与GenBank所下载的多刺裸腹溞(Moina macrocopa)的16S rDNA序列相似度为99%,遗传距离(K2P双参考模型)为0.5%,属种内范围;两个地区的短型裸腹溞测得的16S rDNA序列与GenBank下载的欧洲短型裸腹溞的16S rDNA序列序列相似度相对较低(88%~90%),遗传距离较大(13.2% ~ 13.5%左右),已达到属内种间分化水平.基于16S rDNA构建的NJ树和贝叶斯树也支持以上结论.结果表明,本研究的发头裸腹溞可能为多刺裸腹溞,本研究用的短型裸腹溞与GenBank下载的欧洲短型裸腹溞已经达到种间分化的标准.由于缺乏物种形态资料和其他分子标记的对比,3种裸腹溞的分类地位还需进行更深入的探讨.

  1. 16S rDNA在婴幼儿配方乳粉阪崎肠杆菌鉴定中的应用%Application of 16S rDNA in Enterobacter Sakazakii Identiifcation for Infant Formula Milk Powder

    Institute of Scientific and Technical Information of China (English)

    林玉宙

    2015-01-01

    选取近几年从婴幼儿配方乳粉生产过程环境及产品中收集、经国标GB/T 4789.40-2010检验和API20E鉴定为阪崎肠杆菌阳性的菌株16株,利用MicroSEQ ID微生物鉴定系统进行16S rDNA基因测序分析,构建系统发育树,鉴定种属。结果显示,这16份经API20E鉴定为阪崎肠杆菌阳性的菌株,经16S rDNA基因测序证实,其中2份为梨形肠杆菌,1份为克氏柠檬酸杆菌,其余13份样品均为阪崎肠杆菌,且与数据库中标准菌株的同源性达到99.5%以上。16S rDNA基因测序方法在婴幼儿配方乳粉企业进行阪崎肠杆菌鉴定和溯源方面具有广阔的前景。%Sixteen Enterobacter sakazaki strains col ected from the environment and products during infant formula milk powder production process and identiifed to be positive by GB/T 4789.40-2010 as wel as API20E were analyzed by 16S rDNA gene se-quencing using MicroSEQ ID microbial identiifcation system,and the system development tree was built to identify the species. The results showed that two of 16 Enterobacter sakazaki strains were Enterobacter pyrinus,and one was Citrobacter koseri,and the other thirteen were Enterobacter sakazaki and the homology with standard Enterobacter sakazaki strain in the database was more than 99.5%. 16S rDNA gene sequencing method has the broad prospect in the identiifcation and traceability of Enterobacter saka-zaki for infant formula enterprises.

  2. Dicer is associated with ribosomal DNA chromatin in mammalian cells.

    Directory of Open Access Journals (Sweden)

    Lasse Sinkkonen

    Full Text Available BACKGROUND: RNA silencing is a common term for pathways utilizing small RNAs as sequence-specific guides to repress gene expression. Components of the RNA silencing machinery are involved in different aspects of chromatin function in numerous organisms. However, association of RNA silencing with chromatin in mammalian cells remains unclear. METHODOLOGY/PRINCIPAL FINDINGS: Immunostaining of mitotic chromosomes with antibodies visualizing either endogenous or ectopically expressed Dicer in mammalian cells revealed association of the protein with ribosomal DNA (rDNA repeats. Chromatin immunoprecipitations and bisulfite sequencing experiments indicated that Dicer is associated with transcribed regions of both active and silenced genes in rDNA arrays of interphase chromosomes. Metabolic labeling of the mouse embryonic stem (ES cells lacking Dicer did not reveal apparent defect in rRNA biogenesis though pre-rRNA synthesis in these cells was decreased, likely as a consequence of their slower growth caused by the loss of miRNAs. We analyzed in detail chromatin structure of rDNA but did not find any epigenetic changes at rDNA loci in Dicer(-/- ES cells. Instead, we found that rDNA methylation is rather low in primary tissues, contrasting with rDNA methylation patterns in transformed cell lines. CONCLUSION/SIGNIFICANCE: We found that Dicer, a key component of RNA silencing pathways, can be detected in association with rDNA chromatin in mammalian cells. The role of this particular localization of Dicer is not readily apparent since the enzyme is associated with rDNA genes regardless of their transcriptional activity. However, localization of Dicer to the transcribed region suggests that transcription may contribute to the Dicer deposition at rDNA chromatin. We hypothesize that Dicer functions in maintaining integrity of rDNA arrays.

  3. The phylogeny of native and exotic scallops cultured in China based on 16S rDNA sequences

    Institute of Scientific and Technical Information of China (English)

    LIU Baozhong; DONG Bo; XIANG Jianhai; WANG Zaizhao

    2007-01-01

    Scallops of the Family Pectinidae are a valuable resource in marine industry of the world.Understanding the phylogeny of the family is important for the development of the industry. In this study,partial 16S mitochondrial rDNA genes were obtained from 8 scallop species that are commonly cultured indigenous and transplanted species in China. Phylogenetic relationships of Pectinidae were analyzed based on the 8 sequences and other 5 published ones in GenBank, representing 9 genera of the family. The molecular phylogeny trees were constructed using 3 methods with software PHYLIP. The results showe that total 13 species of scallops clustered in 4 clades. Pecten maximus joins P. jacobaeus then Amusium pleuronectes in cluster, indicating close relationship of genus Amusium with Pecten in evolution. P. yessoensis is close to Chlamysfarreri and C. islandica. No enough material was available to single out genus Patinopecten as an independent monophyletic subfamily. The position ofAdamussium colbecki indicates that it is far from genus Pecten but near to genus Chlamys in evolution.

  4. Characterization of Lactobacillus from Algerian goat's milk based on phenotypic, 16S rDNA sequencing and their technological properties

    Directory of Open Access Journals (Sweden)

    Ahmed Marroki

    2011-03-01

    Full Text Available Nineteen strains of Lactobacillus isolated from goat's milk from farms in north-west of Algeria were characterized. Isolates were identified by phenotypic, physiological and genotypic methods and some of their important technological properties were studied. Phenotypic characterization was carried out by studying physiological, morphological characteristics and carbohydrate fermentation patterns using API 50 CHL system. Isolates were also characterized by partial 16S rDNA sequencing. Results obtained with phenotypic methods were correlated with the genotypic characterization and 13 isolates were identified as L. plantarum, two isolates as L. rhamnosus and one isolate as L. fermentum. Three isolates identified as L. plantarum by phenotypic characterization were found to be L. pentosus by the genotypic method. A large diversity in technological properties (acid production in skim milk, exopolysaccharide production, aminopeptidase activity, antibacterial activity and antibiotic susceptibility was observed. Based on these results, two strains of L. plantarum (LbMS16 and LbMS21 and one strain of L. rhamnosus (LbMF25 have been tentatively selected for use as starter cultures in the manufacture of artisanal fermented dairy products in Algeria.

  5. Analysis of the chronic wound microbiota of 2,963 patients by 16S rDNA pyrosequencing.

    Science.gov (United States)

    Wolcott, Randall D; Hanson, John D; Rees, Eric J; Koenig, Lawrence D; Phillips, Caleb D; Wolcott, Richard A; Cox, Stephen B; White, Jennifer S

    2016-01-01

    The extent to which microorganisms impair wound healing is an ongoing controversy in the management of chronic wounds. Because the high diversity and extreme variability of the microbiota between individual chronic wounds lead to inconsistent findings in small cohort studies, evaluation of a large number of chronic wounds using identical sequencing and bioinformatics methods is necessary for clinicians to be able to select appropriate empiric therapies. In this study, we utilized 16S rDNA pyrosequencing to analyze the composition of the bacterial communities present in samples obtained from patients with chronic diabetic foot ulcers (N = 910), venous leg ulcers (N = 916), decubitus ulcers (N = 767), and nonhealing surgical wounds (N = 370). The wound samples contained a high proportion of Staphylococcus and Pseudomonas species in 63 and 25% of all wounds, respectively; however, a high prevalence of anaerobic bacteria and bacteria traditionally considered commensalistic was also observed. Our results suggest that neither patient demographics nor wound type influenced the bacterial composition of the chronic wound microbiome. Collectively, these findings indicate that empiric antibiotic selection need not be based on nor altered for wound type. Furthermore, the results provide a much clearer understanding of chronic wound microbiota in general; clinical application of this new knowledge over time may help in its translation to improved wound healing outcomes. PMID:26463872

  6. Ribosomal DNA Integrating rAAV-rDNA Vectors Allow for Stable Transgene Expression

    OpenAIRE

    Lisowski, Leszek; Lau, Ashley; Wang, Zhongya; Zhang, Yue(Walter Burke Institute for Theoretical Physics, California Institute of Technology, Pasadena, CA, 91125, U.S.A.); Zhang, Feijie; Grompe, Markus; Kay, Mark A

    2012-01-01

    Although recombinant adeno-associated virus (rAAV) vectors are proving to be efficacious in clinical trials, the episomal character of the delivered transgene restricts their effectiveness to use in quiescent tissues, and may not provide lifelong expression. In contrast, integrating vectors enhance the risk of insertional mutagenesis. In an attempt to overcome both of these limitations, we created new rAAV-rDNA vectors, with an expression cassette flanked by ribosomal DNA (rDNA) sequences cap...

  7. Epistasis analysis of 16S rRNA ram mutations helps define the conformational dynamics of the ribosome that influence decoding.

    Science.gov (United States)

    Ying, Lanqing; Fredrick, Kurt

    2016-04-01

    The ribosome actively participates in decoding, with a tRNA-dependent rearrangement of the 30S A site playing a key role. Ribosomal ambiguity (ram) mutations have mapped not only to the A site but also to the h12/S4/S5 region and intersubunit bridge B8, implicating other conformational changes such as 30S shoulder rotation and B8 disruption in the mechanism of decoding. Recent crystallographic data have revealed that mutation G299A in helix h12 allosterically promotes B8 disruption, raising the question of whether G299A and/or other ram mutations act mainly via B8. Here, we compared the effects of each of several ram mutations in the absence and presence of mutation h8Δ2, which effectively takes out bridge B8. The data obtained suggest that a subset of mutations including G299A act in part via B8 but predominantly through another mechanism. We also found that G299A in h12 and G347U in h14 each stabilize tRNA in the A site. Collectively, these data support a model in which rearrangement of the 30S A site, inward shoulder rotation, and bridge B8 disruption are loosely coupled events, all of which promote progression along the productive pathway toward peptide bond formation.

  8. Performance of 16s rDNA Primer Pairs in the Study of Rhizosphere and Endosphere Bacterial Microbiomes in Metabarcoding Studies.

    Science.gov (United States)

    Beckers, Bram; Op De Beeck, Michiel; Thijs, Sofie; Truyens, Sascha; Weyens, Nele; Boerjan, Wout; Vangronsveld, Jaco

    2016-01-01

    Next-generation sequencing technologies have revolutionized the methods for studying microbial ecology by enabling high-resolution community profiling. However, the use of these technologies in unraveling the plant microbiome remains challenging. Many bacterial 16S rDNA primer pairs also exhibit high affinity for non-target DNA such as plastid (mostly chloroplast) DNA and mitochondrial DNA. Therefore, we experimentally tested a series of commonly used primers for the analysis of plant-associated bacterial communities using 454 pyrosequencing. We evaluated the performance of all selected primer pairs in the study of the bacterial microbiomes present in the rhizosphere soil, root, stem and leaf endosphere of field-grown poplar trees (Populus tremula × Populus alba) based on (a) co-amplification of non-target DNA, (b) low amplification efficiency for pure chloroplast DNA (real-time PCR), (c) high retrieval of bacterial 16S rDNA, (d) high operational taxonomic unit (OTU) richness and Inverse Simpson diversity and (e) taxonomic assignment of reads. Results indicate that experimental evaluation of primers provide valuable information that could contribute in the selection of suitable primer pairs for 16S rDNA metabarcoding studies in plant-microbiota research. Furthermore, we show that primer pair 799F-1391R outperforms all other primer pairs in our study in the elimination of non-target DNA and retrieval of bacterial OTUs. PMID:27242686

  9. Phylogenetic systematics of Barn Owl (Tyto alba (Scopoli, 1769 complex inferred from mitochondrial rDNA (16S rRNA taxonomic implication

    Directory of Open Access Journals (Sweden)

    Mansour Aliabadian

    2012-09-01

    Full Text Available The Barn owl, Tyto alba (Scopoli, 1769, occurs worldwide and shows a considerable amount of morphological and geographical variations, leading to the recognition of many subspecies throughout the world. Yet, no comprehensive study has not been done on this species. Data from mitochondrial gene (16S Ribosomal RNA (16S with 569 bp length were analyzed for 41 individuals around the world. Maximum likelihood (ML, maximum parsimony (MP and Bayesian analysis showed two distinct clades including alba clad (old world and furcata clad (new world. The amount of genetic variation within each of these clades ranged from 0.5-1.7 but variation between clades was 3.7. This data may suggest that Barn owls of the Old World may be a separate species from those of the New World.

  10. 基于16S rDNA序列和RFLP分析的病鳗分离菌株鉴定%Identification of Bacteria Isolated from Diseased Eels Using 16S rDNA PCR / RFLP Analysis

    Institute of Scientific and Technical Information of China (English)

    郭松林; 关瑞章; 冯建军; 杨求华

    2012-01-01

    Using 16S rDNA gene sequences and restriction fragment length polymorphism (RFLP) a- nalysis, the study initially identified 30 strains of bacteria isolated from European eel (Anguilla anguilla) , Japanese eel (Anguilla japonica) and American eel (Anguilla rostrata) according to the homology compari- son with bacterial 16S rDNA gene sequence which had been submitted into the C, eneBank database. The re- sults showed that the 30 bacteria could be broadly divided into 7 genera, including Aeromonas sp. , Pseudo- monas sp. , P/es/omonas sp. , Klebsh:lla sp. , Citrobacter sp. , Acinetobacter sp. and Enterobacter sp. Re- sults of the study indicated some of the isolates could be suspected as pathogenic strains which caused diseases to eels.%结合16S rDNA基因序列和限制性片段长度多态性(RFLP)的分析方法,通过与GenBank库中已递交的细菌16S rDNA基因序列进行同源性比较,对分离自发病鳗鲡(欧洲鳗鲡,日本鳗鲡和美洲鳗鲡)的30株细菌进行初步鉴定和分类.结果表明,这些细菌可大致分为气单胞菌属(Aeromonas sp.)、假单胞菌属(Pseudomonas sp.)、邻单胞菌属(Plesiomonas sp.)、克雷伯氏菌属(Klebsiella sp.)、柠檬酸杆菌属(Citrobacter sp.)、不动杆菌属(Acinetobacter sp.)和肠杆菌属(Enterobacter sp.)等7个菌属.分析认为,部分分离菌株可能是引起鳗鲡病害的疑似致病性菌株.

  11. Identification of Corn Bacterial Wilt Pathogen by Nested-PCR Based on 16S rDNA%16S nested-PCR技术检测玉米细菌性枯萎病菌

    Institute of Scientific and Technical Information of China (English)

    吴琼; 陈枝楠; 范怀忠; 金显忠

    2005-01-01

    玉米细菌性枯萎病是玉米上的重要种传病害,病原菌为Pantoea stewartii subsp.stewartii.本研究设计了16S通用引物,扩增该病菌及其近似种的16S rDNA,通过序列测定和分析,针对该病菌设计了特异性引物,采用nested-PCR技术,能够准确地区别该病菌及其近似种,检测的灵敏度在DNA水平上达到10-3pg级,检测活菌则达到2 cfu.检测人工污染的玉米种子时,不受种子提取液中其它物质的干扰,灵敏度依然达到2 cfu.%Pantoea stewartii subsp. stewartii is the seed-borne causative agent of bacterial wilt and leaf blight of sweet corn and maize. In this study, a specific 16S rDNA-based nested-PCR (nPCR) was developed to identify the bacterium from a range of closely related bacteria. This PCR assay was proved to be highly sensitive with the detection limit of 10 -3pg genomic DNA or 2 colony forming units (cfu). Moreover, this PCR assay successfully detected the target bacteria as few as 2 cfu when tested with artificially contaminated seeds, and the sensitivity was not affected by seed compounds.

  12. Plastid 16s rDNA sequence analysis of Phaeocystis glogosa from South China Sea%南海球形棕囊藻质体16S rDNA序列分析

    Institute of Scientific and Technical Information of China (English)

    马奔; 章群; 司从利; 黄小彧

    2011-01-01

    测定了采自香港2株球形棕囊藻和湛江1株等鞭金藻质体16S rDNA基因序列,结合GenBank中下载的32条同源序列,分析序列特征并构建分子系统树.发现600 bp序列中有可变位点42个,简约信息位点33个,可变位点和简约信息位点分别为全序列的7.0%和5.5%.A+T的含量(52.5%)略大于C+G含量(47.5%),与已报道的棕囊藻属叶绿体和线粒体基因相似;在分子系统树上,同属藻种聚类在一起,属间遗传距离分别为0.025 5~0.050 3.棕囊藻属属内遗传距离0-0.005 0,不同藻种相混杂,并未独立成支;质体16s rDNA部分序列虽不能区分棕囊藻属内不同藻种,但能鉴定出GenBank中27个环境样品为棕囊藻属藻株,从而能确定其地理分布和相对丰度,对棕囊藻赤潮的预测预报具有重要意义.质体16srDNA在其他赤潮藻类物种鉴定方面的应用需要进一步研究.%Partial sequences of plastid 16S rDNA in the two Strains of Phaeocystis globosa isolated from Hong Kong and one Isochrysis strain isolated from Zhangjiang in South China Sea were determined,combined with 32 homologous sequences downloaded from GenBank, the sequence information were analyzed and phylogenetic tree were reconstructed. 42 variable sites and 33 parsimony-informative sites were found in the aligned 600 bp sequences, 7.0% and 5.5% sites were variable and parsimony-informative. The contents of (A+TX52.5%) were a little more than those of (G+C)(47.5%), which were similar to those plastid and mitochondrial genes of Phaeocystis..In the phylogenetic tree, algae strains of the same genus were clustered, and genetic distances among genus were between 0.025 5-0.050 3. Genetic distances within the genus Phaeocystis were less than 0.005 0, and different species were intertwined without isolated clade for each species. Although partial sequences of plastid 16S rDNA could not differentiate different species in the genus Phaeocystis, which may due to the shortage of

  13. 16s rDNA文库法分析番石榴果实蝇共生菌组成%Composition of symbiotic bacteria associated with Bactrocera correcta analyzed by 16s rDNA libraries

    Institute of Scientific and Technical Information of China (English)

    戴阳; 李志红; 柳丽君; 吴佳教; 邓裕亮

    2012-01-01

    [Objective] The composition of symbiotic bacteria associated with Guava fruit fly, Bacirocera correcta (Bezzi), was investigated to provide the basis for further study on physiological function of the symbionts and co-evolution between bacteria and the host. [Method] 16s rDNA libraries of laboratory population for B. correcta were constructed, and BLAST analysis of bacterial composition and abundance was carried out in this study. [Result] The dominant symbionts in B. correcta male adults were Pseudomonas aeruginosa and Lactococcus lactis, while symbiotic bacteria in female adults were Enterobacter bacteria. [Conclusion] Various bacteria are present in the Guava fruit fly, B. correcta.%[目的]探索分析番石榴果实蝇[ Bactrocera correcta (Bezzi)]的共生菌组成,为进一步探索共生菌的生理功能以及与宿主的协同进化关系奠定基础.[方法]构建番石榴果实蝇室内种群共生菌的16s rDNA文库,BLAST分析其共生菌的组成以及丰度.[结果]室内雄虫共生菌主要为Pseudomonas aeruginosa和Lactococcus lactis,雌虫共生菌主要为Enterobacter属的细菌.[结论]本研究结果证明番石榴果实蝇存在多种共生菌.

  14. Bacterial diversity in a soil sample from Uranium mining waste pile as estimated via a culture-independent 16S rDNA approach

    International Nuclear Information System (INIS)

    Bacterial diversity was studied in a soil sample collected from a uranium mining waste pile situated near the town of Johanngeorgenstadt, Germany. As estimated by ICP-MS analysis the studied sample was highly contaminated with Fe, Al, Mn, Zn, As, Pb and U. The 16S rDNA retrieval, applied in this study, demonstrated that more than the half of the clones of the constructed 16S rDNA library were represented by individual RFLP profiles. This indicates that the composition of the bacterial community in the sample was very complex. However, several 16S rDNA RFLP groups were found to be predominant and they were subjected to a sequence analysis. The most predominant group, which represented about 13% of the clones of the 16S rDNA library, was affiliated with the Holophaga/Acidobacterium phylum. Significant was also the number of the proteobacterial sequences which were distributed in one predominant α-proteobacterial cluster representing 11% of the total number of clones and in two equal-sized β- and γ-proteobacterial clusters representing each 6% of the clones. Two smaller groups representing both 2% of the clones were affiliated with Nitrospira and with the novel division WS3. Three of the analysed sequences were evaluated as a novel, not yet described lineage and one as a putative chimera. (authors)

  15. 16S rRNA Gene Sequence Analysis of Drinking Water Using RNA and DNA Extracts as Targets for Clone Library Development - Poster

    Science.gov (United States)

    We examined the bacterial composition of chlorinated drinking water using 16S rRNA gene clone libraries derived from RNA and DNA extracted from twelve water samples collected in three different months (June, August, and September of 2007). Phylogenetic analysis of 1234 and 1117 ...

  16. CTCF regulates the local epigenetic state of ribosomal DNA repeats

    Directory of Open Access Journals (Sweden)

    van de Nobelen Suzanne

    2010-11-01

    Full Text Available Abstract Background CCCTC binding factor (CTCF is a highly conserved zinc finger protein, which is involved in chromatin organization, local histone modifications, and RNA polymerase II-mediated gene transcription. CTCF may act by binding tightly to DNA and recruiting other proteins to mediate its various functions in the nucleus. To further explore the role of this essential factor, we used a mass spectrometry-based approach to screen for novel CTCF-interacting partners. Results Using biotinylated CTCF as bait, we identified upstream binding factor (UBF and multiple other components of the RNA polymerase I complex as potential CTCF-interacting partners. Interestingly, CTCFL, the testis-specific paralog of CTCF, also binds UBF. The interaction between CTCF(L and UBF is direct, and requires the zinc finger domain of CTCF(L and the high mobility group (HMG-box 1 and dimerization domain of UBF. Because UBF is involved in RNA polymerase I-mediated ribosomal (rRNA transcription, we analyzed CTCF binding to the rDNA repeat. We found that CTCF bound to a site upstream of the rDNA spacer promoter and preferred non-methylated over methylated rDNA. DNA binding by CTCF in turn stimulated binding of UBF. Absence of CTCF in cultured cells resulted in decreased association of UBF with rDNA and in nucleolar fusion. Furthermore, lack of CTCF led to reduced binding of RNA polymerase I and variant histone H2A.Z near the rDNA spacer promoter, a loss of specific histone modifications, and diminished transcription of non-coding RNA from the spacer promoter. Conclusions UBF is the first common interaction partner of CTCF and CTCFL, suggesting a role for these proteins in chromatin organization of the rDNA repeats. We propose that CTCF affects RNA polymerase I-mediated events globally by controlling nucleolar number, and locally by regulating chromatin at the rDNA spacer promoter, similar to RNA polymerase II promoters. CTCF may load UBF onto rDNA, thereby forming

  17. Coamplification of eukaryotic DNA with 16S rRNA gene-based PCR primers: possible consequences for population fingerprinting of complex microbial communities.

    Science.gov (United States)

    Huys, Geert; Vanhoutte, Tom; Joossens, Marie; Mahious, Amal S; De Brandt, Evie; Vermeire, Severine; Swings, Jean

    2008-06-01

    The main aim of this study was to evaluate the specificity of three commonly used 16S rRNA gene-based polymerase chain reaction (PCR) primer sets for bacterial community analysis of samples contaminated with eukaryotic DNA. The specificity of primer sets targeting the V3, V3-V5, and V6-V8 hypervariable regions of the 16S rRNA gene was investigated in silico and by community fingerprinting of human and fish intestinal samples. Both in silico and PCR-based analysis revealed cross-reactivity of the V3 and V3-V5 primers with the 18S rRNA gene of human and sturgeon. The consequences of this primer anomaly were illustrated by denaturing gradient gel electrophoresis (DGGE) profiling of microbial communities in human feces and mixed gut of Siberian sturgeon. DGGE profiling indicated that the cross-reactivity of 16S rRNA gene primers with nontarget eukaryotic DNA might lead to an overestimation of bacterial biodiversity. This study has confirmed previous sporadic indications in literature indicating that several commonly applied 16S rRNA gene primer sets lack specificity toward bacteria in the presence of eukaryotic DNA. The phenomenon of cross-reactivity is a potential source of systematic error in all biodiversity studies where no subsequent analysis of individual community amplicons by cloning and sequencing is performed.

  18. Self-organizing maps: A tool to ascertain taxonomic relatedness based on features derived from 16S rDNA sequence

    Indian Academy of Sciences (India)

    D V Raje; H J Purohit; Y P Badhe; S S Tambe; B D Kulkarni

    2010-12-01

    Exploitation of microbial wealth, of which almost 95% or more is still unexplored, is a growing need. The taxonomic placements of a new isolate based on phenotypic characteristics are now being supported by information preserved in the 16S rRNA gene. However, the analysis of 16S rDNA sequences retrieved from metagenome, by the available bioinformatics tools, is subject to limitations. In this study, the occurrences of nucleotide features in 16S rDNA sequences have been used to ascertain the taxonomic placement of organisms. The tetra- and penta-nucleotide features were extracted from the training data set of the 16S rDNA sequence, and was subjected to an artificial neural network (ANN) based tool known as self-organizing map (SOM), which helped in visualization of unsupervised classification. For selection of significant features, principal component analysis (PCA) or curvilinear component analysis (CCA) was applied. The SOM along with these techniques could discriminate the sample sequences with more than 90% accuracy, highlighting the relevance of features. To ascertain the confidence level in the developed classification approach, the test data set was specifically evaluated for Thiobacillus, with Acidiphilium, Paracocus and Starkeya, which are taxonomically reassigned. The evaluation proved the excellent generalization capability of the developed tool. The topology of genera in SOM supported the conventional chemo-biochemical classification reported in the Bergey manual.

  19. The 16S rDNA Phylogenetic Composition of Bacteria Implicated in Sulfur Redox Cycles and Associated Sulfur Isotope Fractionation

    Science.gov (United States)

    Bicknell, B. T.; Batts, J. E.; Krouse, H. R.

    2006-12-01

    The reduction of sulfate ion to sulfide species by sulfate reducing bacteria (SRB) is accompanied by sulfur isotope fractionation, measured in terms of changes in the δ^{34}S values for sulfate and sulfide ions relative to a defined standard. In open environments, the S-isotope compositions of sulfate and sulfide can be affected by loss from the system of sulfide species as gaseous H2S, insoluble metal sulfides such as FeS2, organic complexes or by re-oxidation. The S-isotope fractionation accompanying bacterial sulfate reduction in nature is often much larger than the maxima obtained in chemical and bacterial sulfate reduction experiments in the laboratory. One mechanism postulated for the large natural S-isotope selectivity depends on repetitive reduction-oxidation cycles. In turn, this would require a level of tolerance to oxygen by SRB in the sedimentary environment, contrary to laboratory experience with SRB strains. Bird Lake (The Coorong, South Australia) is a small calcareous, evaporative lake, where average Δ^{34}S (δ^{34}Ssulfate - δ^{34}Ssulfide) values for groundwater at 16 of the 27 sites sampled periodically since 1974, vary from 15.0 ‰ to 62.3 ‰ within the range -1.8 ‰ to 70.6 ‰. Wide fluctuations in δ34Ssulfide values at individual sites are the significant factor affecting the variability of Δ^{34}S values. Values for δ18Osulfate are elevated over that of the sulfate source to an unusual extent, reflecting re-oxidation of sulfur species and O- isotope exchange between some of these species and water. One aspect of investigations at Bird Lake was the evaluation of bacterial populations in subsurface sediments and their role in sulfur cycling. To achieve this, microcosms were established with subsurface sediment and incubated under a nitrogen atmosphere, for up to 119 days. These were sampled at various times to determine sulfur species concentrations and sulfur isotope fractionation and to generate 16S rDNA clone libraries. Results

  20. Dynamic changes of intestinal 16S rDNA metagenome in 5 infants%动态监测婴儿肠道16S rDNA宏基因组5例报告

    Institute of Scientific and Technical Information of China (English)

    马丽亚; 张敏; 王辉林; 陈睿; 黄艳; 梁小琴; 卢光进

    2014-01-01

    目的:探讨婴儿肠道16S rDNA宏基因组的动态变化。方法收集5例健康婴儿生后3 d、1个月、6个月、1岁时粪便样本共17份,提取细菌总DNA,采用新一代高通量测序技术对16S rDNA的V6高变区测序并进行物种分类、丰度及多样性分析。结果17份样品共产生原始测序数据为2190.66 Mbp,Operational Taxonomic Units(OTU)数量36~308;优势菌门包括变形菌门、厚壁菌门、拟杆菌门和放线菌门;不同婴儿间肠道菌群分布有差异;科水平>1%的物种生后3 d时2~4种,1个月、6个月时增至最多7种,1岁时达10种;4个时间点的npShannon和Simpson指数均值分别为1.117、1.460、2.088、2.50和0.443、0.408、0.229、0.143。结论婴儿粪便中含丰富细菌基因组;细菌物种丰度及分类存在个体差异;细菌多样性随日龄而增加,婴儿肠道菌群结构出生后逐渐趋向复杂和多样。%Objective To investigate the dynamic changes of intestinal 16S rDNA metagenome in healthy infants. Methods Seventeen fecal samples were collected at ages of 3 days, 1 month, 6 months and 1 year in 5 infants. Total bacterial DNAs were extracted and submitted high throughout sequencing on the V6 viable region of 16S rDNA. Tags and Operational Taxonomic Units (OTU) were then obtained and analysis of taxonomy, abundance and alpha diversity were performed. Results In total 2 190.66 Mbp raw data in 17 samples were produced. The OTU numbers ranged from 36 to 308. The dominate phylum included Proteobacteria, Firmicutes and Bacteroidetes and Actinobacteria. The bacterial families>1%increased from only 2-4 per sample on day 3 to 7 at 1 or 6 months, 10 at 12 months. The average npShannon and Simpson index on day 3, at 1 month, 6 months and 1 year were 1.117, 1.460, 2.088, 2.50 and 0.443, 0.408, 0.229, 0.143 respectively. Conclusions Infants’ intestines harbor abounding bacterial genomes. Distinct individual differences exist in infants in terms of

  1. Micelle PCR reduces chimera formation in 16S rRNA profiling of complex microbial DNA mixtures

    NARCIS (Netherlands)

    S.A. Boers (Stefan A.); J.P. Hays (John P.); R. Jansen (Ruud)

    2015-01-01

    textabstract16S rRNA gene profiling has revolutionized the field of microbial ecology. Many researchers in various fields have embraced this technology to investigate bacterial compositions of samples derived from many different ecosystems. However, it is important to acknowledge the current limitat

  2. Phylogenetic relationships linking Duttaphrynus (Amphibia: Anura: Bufonidae) species based on 12S and 16S rDNA sequences.

    Science.gov (United States)

    Pratihar, Suman; Bhattacharya, Manojit; Deuti, Kaushik

    2016-07-01

    Genus Duttaphrynus (Amphibia: Anura: Bufonidae) is endemic to southwestern and southern China and throughout southern Asia. Duttaphrynus phylogeny was also under debate for many years. 12S and 16S rDNAs help us to elucidate Duttaphrynus phylogeny. PMID:26155970

  3. ABH2 Couples Regulation of Ribosomal DNA Transcription with DNA Alkylation Repair

    Directory of Open Access Journals (Sweden)

    Pishun Li

    2013-08-01

    Full Text Available Transcription has been linked to DNA damage. How the most highly transcribed mammalian ribosomal (rDNA genes maintain genome integrity in the absence of transcription-coupled DNA damage repair is poorly understood. Here, we report that ABH2/ALKBH2, a DNA alkylation repair enzyme, is highly enriched in the nucleolus. ABH2 interacts with DNA repair proteins Ku70 and Ku80 as well as nucleolar proteins nucleolin, nucleophosmin 1, and upstream binding factor (UBF. ABH2 associates with and promotes rDNA transcription through its DNA repair activity. ABH2 knockdown impairs rDNA transcription and leads to increased single-stranded and double-stranded DNA breaks that are more pronounced in the rDNA genes, whereas ABH2 overexpression protects cells from methyl-methanesulfonate-induced DNA damage and inhibition of rDNA transcription. In response to massive alkylation damage, ABH2 rapidly redistributes from the nucleolus to nucleoplasm. Our study thus reveals a critical role of ABH2 in maintaining rDNA gene integrity and transcription and provides insight into the ABH2 DNA repair function.

  4. Length polymorphisms for intergenic spacer regions of 16S-23S rDNA in members of the new hydrogen-producing bacteria

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A method based on PCR amplification of the 16S rRNA gene (rDNA) -23S rDNA intergenic spacer regions (ISR) was developed for the identification of species within the novel group hydrogen-producing anaerobes. The sizes of the PCR products varied from 1264 to 398 bp. Strain of isolate Rennanqilyf 3 was characterized as having products of 1262, 398, 638, 437 and 436 bp. The isolate Rennanqilyf 1 had product of 1264 bp. The isolate Rennanqilyf 13 had products of 1261, 579 and 485 bp. Of the 3 species of the novel group hydrogenproducing anaerobes examined, no one was indistinguishable. Two environmental isolates were identified as hydrogen-producing bacteria, which were new species in present taxon. Rennanqilyf 3 could not be associated With any Clostridium sp. Studied. Rennanqilyf 1 could be classified into Clostridium genus. The combination between 16S rDNA equencing and length polymorphisms of IRS in 16S-23S rDNA is a better method for determining species of the hydrogen-producing bacteria.

  5. Characterization of bacterial diversity in pulque, a traditional Mexican alcoholic fermented beverage, as determined by 16S rDNA analysis.

    Science.gov (United States)

    Escalante, Adelfo; Rodríguez, María Elena; Martínez, Alfredo; López-Munguía, Agustín; Bolívar, Francisco; Gosset, Guillermo

    2004-06-15

    The bacterial diversity in pulque, a traditional Mexican alcoholic fermented beverage, was studied in 16S rDNA clone libraries from three pulque samples. Sequenced clones identified as Lactobacillus acidophilus, Lactobacillus strain ASF360, L. kefir, L. acetotolerans, L. hilgardii, L. plantarum, Leuconostoc pseudomesenteroides, Microbacterium arborescens, Flavobacterium johnsoniae, Acetobacter pomorium, Gluconobacter oxydans, and Hafnia alvei, were detected for the first time in pulque. Identity of 16S rDNA sequenced clones showed that bacterial diversity present among pulque samples is dominated by Lactobacillus species (80.97%). Seventy-eight clones exhibited less than 95% of relatedness to NCBI database sequences, which may indicate the presence of new species in pulque samples.

  6. Vertical stratification of microbial communities in the Red Sea revealed by 16S rDNA pyrosequencing

    OpenAIRE

    Qian, Pei-Yuan; Wang, Yong; Lee, On On; Lau, Stanley C K; Yang, Jiangke; Lafi, Feras F.; Al-Suwailem, Abdulaziz; Wong, Tim YH

    2010-01-01

    The ecosystems of the Red Sea are among the least-explored microbial habitats in the marine environment. In this study, we investigated the microbial communities in the water column overlying the Atlantis II Deep and Discovery Deep in the Red Sea. Taxonomic classification of pyrosequencing reads of the 16S rRNA gene amplicons showed vertical stratification of microbial diversity from the surface water to 1500 m below the surface. Significant differences in both bacterial and archaeal diversit...

  7. Seasonal Succession Leads to Habitat-Dependent Differentiation in Ribosomal RNA:DNA Ratios among Freshwater Lake Bacteria.

    Science.gov (United States)

    Denef, Vincent J; Fujimoto, Masanori; Berry, Michelle A; Schmidt, Marian L

    2016-01-01

    Relative abundance profiles of bacterial populations measured by sequencing DNA or RNA of marker genes can widely differ. These differences, made apparent when calculating ribosomal RNA:DNA ratios, have been interpreted as variable activities of bacterial populations. However, inconsistent correlations between ribosomal RNA:DNA ratios and metabolic activity or growth rates have led to a more conservative interpretation of this metric as the cellular protein synthesis potential (PSP). Little is known, particularly in freshwater systems, about how PSP varies for specific taxa across temporal and spatial environmental gradients and how conserved PSP is across bacterial phylogeny. Here, we generated 16S rRNA gene sequencing data using simultaneously extracted DNA and RNA from fractionated (free-living and particulate) water samples taken seasonally along a eutrophic freshwater estuary to oligotrophic pelagic transect in Lake Michigan. In contrast to previous reports, we observed frequent clustering of DNA and RNA data from the same sample. Analysis of the overlap in taxa detected at the RNA and DNA level indicated that microbial dormancy may be more common in the estuary, the particulate fraction, and during the stratified period. Across spatiotemporal gradients, PSP was often conserved at the phylum and class levels. PSPs for specific taxa were more similar across habitats in spring than in summer and fall. This was most notable for PSPs of the same taxa when located in the free-living or particulate fractions, but also when contrasting surface to deep, and estuary to Lake Michigan communities. Our results show that community composition assessed by RNA and DNA measurements are more similar than previously assumed in freshwater systems. However, the similarity between RNA and DNA measurements and taxa-specific PSPs that drive community-level similarities are conditional on spatiotemporal factors. PMID:27199936

  8. Seasonal succession leads to habitat-dependent differentiation in ribosomal RNA:DNA ratios among freshwater lake bacteria

    Directory of Open Access Journals (Sweden)

    Vincent J Denef

    2016-04-01

    Full Text Available Relative abundance profiles of bacterial populations measured by sequencing DNA or RNA of marker genes can widely differ. These differences, made apparent when calculating ribosomal RNA:DNA ratios, have been interpreted as variable activities of bacterial populations. However, inconsistent correlations between ribosomal RNA:DNA ratios and metabolic activity or growth rates have led to a more conservative interpretation of this metric as the cellular protein synthesis potential (PSP. Little is known, particularly in freshwater systems, about how PSP varies for specific taxa across temporal and spatial environmental gradients and how conserved PSP is across bacterial phylogeny. Here, we generated 16S rRNA gene sequencing data using simultaneously extracted DNA and RNA from fractionated (free-living and particulate water samples taken seasonally along a eutrophic freshwater estuary to oligotrophic pelagic transect in Lake Michigan. In contrast to previous reports, we observed frequent clustering of DNA and RNA data from the same sample. Analysis of the overlap in taxa detected at the RNA and DNA level indicated that microbial dormancy may be more common in the estuary, the particulate fraction, and during the stratified period. Across spatiotemporal gradients, PSP was often conserved at the phylum and class levels. PSPs for specific taxa were more similar across habitats in spring than in summer and fall. This was most notable for PSPs of the same taxa when located in the free-living or particulate fractions, but also when contrasting surface to deep, and estuary to Lake Michigan communities. Our results show that community composition assessed by RNA and DNA measurements are more similar than previously assumed in freshwater systems. However, the similarity between RNA and DNA measurements and taxa-specific PSPs that drive community-level similarities are conditional on spatiotemporal factors.

  9. Seasonal Succession Leads to Habitat-Dependent Differentiation in Ribosomal RNA:DNA Ratios among Freshwater Lake Bacteria

    Science.gov (United States)

    Denef, Vincent J.; Fujimoto, Masanori; Berry, Michelle A.; Schmidt, Marian L.

    2016-01-01

    Relative abundance profiles of bacterial populations measured by sequencing DNA or RNA of marker genes can widely differ. These differences, made apparent when calculating ribosomal RNA:DNA ratios, have been interpreted as variable activities of bacterial populations. However, inconsistent correlations between ribosomal RNA:DNA ratios and metabolic activity or growth rates have led to a more conservative interpretation of this metric as the cellular protein synthesis potential (PSP). Little is known, particularly in freshwater systems, about how PSP varies for specific taxa across temporal and spatial environmental gradients and how conserved PSP is across bacterial phylogeny. Here, we generated 16S rRNA gene sequencing data using simultaneously extracted DNA and RNA from fractionated (free-living and particulate) water samples taken seasonally along a eutrophic freshwater estuary to oligotrophic pelagic transect in Lake Michigan. In contrast to previous reports, we observed frequent clustering of DNA and RNA data from the same sample. Analysis of the overlap in taxa detected at the RNA and DNA level indicated that microbial dormancy may be more common in the estuary, the particulate fraction, and during the stratified period. Across spatiotemporal gradients, PSP was often conserved at the phylum and class levels. PSPs for specific taxa were more similar across habitats in spring than in summer and fall. This was most notable for PSPs of the same taxa when located in the free-living or particulate fractions, but also when contrasting surface to deep, and estuary to Lake Michigan communities. Our results show that community composition assessed by RNA and DNA measurements are more similar than previously assumed in freshwater systems. However, the similarity between RNA and DNA measurements and taxa-specific PSPs that drive community-level similarities are conditional on spatiotemporal factors. PMID:27199936

  10. Thinking beside the box: Should we care about the non-coding strand of the 16S rRNA gene?

    Science.gov (United States)

    Garcia-Mazcorro, Jose F; Barcenas-Walls, Jose R

    2016-08-01

    The 16S rRNA gene (16S rDNA) codes for RNA that plays a fundamental role during translation in the ribosome and is used extensively as a marker gene to establish relationships among bacteria. However, the complementary non-coding 16S rDNA (nc16S rDNA) has been ignored. An idea emerged in the course of analyzing bacterial 16S rDNA sequences in search for nucleotide composition and substitution patterns: Does the nc16S rDNA code? If so, what does it code for? More importantly: Does 16S rDNA evolution reflect its own evolution or the evolution of its counterpart nc16S rDNA? The objective of this minireview is to discuss these thoughts. nc strands often encode small RNAs (sRNAs), ancient components of gene regulation. nc16S rDNA sequences from different bacterial groups were used to search for possible matches in the Bacterial Small Regulatory RNA Database. Intriguingly, the sequence of one published sRNA obtained from Legionella pneumophila (GenBank: AE0173541) showed high non-random similarity with nc16S rDNA corresponding in part to the V5 region especially from Legionella and relatives. While the target(s) of this sRNA is unclear at the moment, its mere existence might open up a new chapter in the use of the 16S rDNA to study relationships among bacteria.

  11. Thinking beside the box: Should we care about the non-coding strand of the 16S rRNA gene?

    Science.gov (United States)

    Garcia-Mazcorro, Jose F; Barcenas-Walls, Jose R

    2016-08-01

    The 16S rRNA gene (16S rDNA) codes for RNA that plays a fundamental role during translation in the ribosome and is used extensively as a marker gene to establish relationships among bacteria. However, the complementary non-coding 16S rDNA (nc16S rDNA) has been ignored. An idea emerged in the course of analyzing bacterial 16S rDNA sequences in search for nucleotide composition and substitution patterns: Does the nc16S rDNA code? If so, what does it code for? More importantly: Does 16S rDNA evolution reflect its own evolution or the evolution of its counterpart nc16S rDNA? The objective of this minireview is to discuss these thoughts. nc strands often encode small RNAs (sRNAs), ancient components of gene regulation. nc16S rDNA sequences from different bacterial groups were used to search for possible matches in the Bacterial Small Regulatory RNA Database. Intriguingly, the sequence of one published sRNA obtained from Legionella pneumophila (GenBank: AE0173541) showed high non-random similarity with nc16S rDNA corresponding in part to the V5 region especially from Legionella and relatives. While the target(s) of this sRNA is unclear at the moment, its mere existence might open up a new chapter in the use of the 16S rDNA to study relationships among bacteria. PMID:27412167

  12. When molecules support morphology: Phylogenetic reconstruction of the family Onuphidae (Eunicida, Annelida) based on 16S rDNA and 18S rDNA.

    Science.gov (United States)

    Budaeva, Nataliya; Schepetov, Dmitry; Zanol, Joana; Neretina, Tatiana; Willassen, Endre

    2016-01-01

    Onuphid polychaetes are tubicolous marine worms commonly reported worldwide from intertidal areas to hadal depths. They often dominate in benthic communities and have economic importance in aquaculture and recreational fishing. Here we report the phylogeny of the family Onuphidae based on the combined analyses of nuclear (18S rDNA) and mitochondrial (16S rDNA) genes. Results of Bayesian and Maximum Likelihood analyses supported the monophyly of Onuphidae and its traditional subdivision into two monophyletic subfamilies: Onuphinae and Hyalinoeciinae. Ten of 22 recognized genera were monophyletic with strong node support; four more genera included in this study were either monotypic or represented by a single species. None of the genera appeared para- or polyphyletic and this indicates a strong congruence between the traditional morphology-based systematics of the family and the newly obtained molecular-based phylogenetic reconstructions. Intergeneric relationships within Hyalinoeciinae were not resolved. Two strongly supported monophyletic groups of genera were recovered within Onuphinae: ((Onuphis, Aponuphis), Diopatra, Paradiopatra) and (Hirsutonuphis, (Paxtonia, (Kinbergonuphis, Mooreonuphis))). A previously accepted hypothesis on the subdivision of Onuphinae into the Onuphis group of genera and the Diopatra group of genera was largely rejected.

  13. Detection of Morganella morganii, a prolific histamine former, by the polymerase chain reaction assay with 16S rDNA-targeted primers.

    Science.gov (United States)

    Kim, Shin-Hee; An, Haejung; Field, Katharine G; Wei, Cheng-I; Velazquez, Jorge Barros; Ben-Gigirey, Begoña; Morrissey, Michael T; Price, Robert J; Pitta, Thomas P

    2003-08-01

    A polymerase chain reaction (PCR) assay for the rapid and sensitive detection of the most prolific histamine former, Morganella morganii, was developed. 16S rDNA targeted PCR primers were designed, and the primer specificity and sensitivity of the PCR assay were evaluated. The 16S rDNA sequence (1,503 bp) for M. morganii showed 95% identity to those for enteric bacteria, i.e., Enterobacter spp., Klebsiella spp., Citrobacter spp., Hafnia alvei, Proteus spp., and Providencia spp. The unique primers for M. morganii were designed on the basis of the variable regions in the 16S rDNA sequence. The primers showed positive reactions with all M. morganii strains tested. However, PCR amplification was not detected when the primers were tested with other enteric or marine bacteria. When the sensitivity of the assay was evaluated, M. morganii was detected at levels ranging from 10(6) to 10(8) CFU/ml in albacore homogenate after the PCR amplification. The sensitivity of the assay was greatly improved with the enrichment of samples, and 9 CFU of M. morganii per ml of albacore homogenate was detected after 6 h of enrichment at 37 degrees C.

  14. 16S rDNA在乳酸菌菌种鉴定及聚类分析上的应用%Application of 16S rDNA fingerprint on the strain identification and traceability isolated from yogurts

    Institute of Scientific and Technical Information of China (English)

    杨柳; 杨捷琳; 谌鸿超; 曹敏仪; 潘良文

    2013-01-01

    Microecological products are paid more and more attention.Most commercial microecological products on local market are the yogurts which contain lactic acid bacteria.The common technology of strain identification are the physiological and biochemical test or the application of PCR with some defects such as time-consuming or need specialized person.We used Riboprinter to complete the subspecies level of identification of 16 lactobacillus bacterias isolated from 11 yogurt samples based on the separation and purification of the bacterias.Not only chose the optimization of the culture conditions,but also established the "Traceability File" used for the quality research.What's more,the use of the 16s rDNA fingerprint analysis and real time PCR helped to confirm the verification of the results from the colony identification.%近年来,微生态制剂日益受到市场关注.市售微生态食品以益生菌酸奶或乳酸饮料为主,其中活的乳酸菌含量及菌株特性是决定微生态制剂质量的关键.目前常用的菌种鉴定技术包括生理生化方法或PCR方法,前者工作量大周期长,后者需要专业人员操作,且难以区分死活细菌.本文选取了11种市售的乳酸菌产品,采用MC、MRL、TPY等乳酸菌专用培养基进行乳酸菌计数及菌种分离,进一步用荧光定量PCR方法验证了产品中常规培养法难以分离的双歧杆菌,在此基础上,采用Riboprinter基因指纹图谱分析仪,对分离自11种酸奶样品的16株乳酸菌菌进行了核酸水平的鉴定,建立了16S rDNA聚类分析分子图谱,方便并简化对微生态产品的质量进行“物证相符”的考证,初步分析了目前市场上市售酸奶所用菌种的种属相关性.

  15. Use of mitochondrial and ribosomal DNA polymorphisms to classify clinical and soil isolates of Histoplasma capsulatum.

    OpenAIRE

    Spitzer, E. D.; Lasker, B A; Travis, S J; Kobayashi, G. S.; Medoff, G

    1989-01-01

    We have developed an improved scheme for the classification of environmental and clinical isolates of Histoplasma capsulatum that is based on analysis of mitochondrial DNA (mtDNA) and ribosomal DNA (rDNA). Strains were initially divided into mtDNA groups according to restriction digests of whole-cell DNA and Southern hybridization with cloned mtDNA probes. Strains within a mtDNA class could be further grouped by polymorphisms in rDNA. The majority of soil and clinical isolates from the United...

  16. Carbonate formation by anaerobic oxidation of methane: Evidence from lipid biomarker and fossil 16S rDNA

    Science.gov (United States)

    Stadnitskaia, A.; Nadezhkin, D.; Abbas, B.; Blinova, V.; Ivanov, M. K.; Sinninghe Damsté, J. S.

    2008-04-01

    Carbonate chimneys and other carbonate structures occur widespread in the Gulf of Cadiz and probably reflect the presence of cold seeps and associated release of methane in the geological past, possibly in the Early Pleistocene, but it is unclear under what conditions and by which processes these carbonates were formed. We studied a fossil methane-related carbonate crust collected from the Kidd mud volcano in the gulf. Concentrations of microbial lipids, their stable carbon isotope composition, sequences of fossil 16S rRNA genes of anaerobic methanotrophic archaea in combination with mineralogical and carbon and oxygen isotopic composition of carbonate were obtained for seven different horizons of the crust. This combination of organic and inorganic geochemical techniques with molecular ecological methods gave a consistent view on processes resulting in the formation of the crust and indicated that it took place in two phases and in a downward direction. Archaeal lipid biomarkers and fossil 16S rRNA gene sequence data revealed the dominance of archaeal ANME-2 group and elevated methane partial pressures during the formation of the top part of the crust. The lower part of the carbonate was likely formed in an environment with reduced methane fluxes as revealed by the dominance of fossil remains of ANME-1 archaea. The combination of these methods can be used as an effective tool to reconstruct in unprecedented detail the palaeo-biogeochemical processes resulting in the formation of carbonate fabrics. This interdisciplinary strategy may also be applied for other fossil methane-derived carbonates, generating new concepts and knowledge about past methane-related carbonate systems.

  17. A unique DNA repair and recombination gene (recN) sequence for identification and intraspecific molecular typing of bacterial wilt pathogen Ralstonia solanacearum and its comparative analysis with ribosomal DNA sequences

    Indian Academy of Sciences (India)

    Aundy Kumar; Thekkan Puthiyaveedu Prameela; Rajamma Suseelabhai

    2013-06-01

    Ribosomal gene sequences are a popular choice for identification of bacterial species and, often, for making phylogenetic interpretations. Although very popular, the sequences of 16S rDNA and 16-23S intergenic sequences often fail to differentiate closely related species of bacteria. The availability of complete genome sequences of bacteria, in the recent years, has accelerated the search for new genome targets for phylogenetic interpretations. The recently published full genome data of nine strains of R. solanacearum, which causes bacterial wilt of crop plants, has provided enormous genomic choices for phylogenetic analysis in this globally important plant pathogen. We have compared a gene candidate recN, which codes for DNA repair and recombination function, with 16S rDNA/16-23S intergenic ribosomal gene sequences for identification and intraspecific phylogenetic interpretations in R. solanacearum. recN gene sequence analysis of R. solanacearum revealed subgroups within phylotypes (or newly proposed species within plant pathogenic genus, Ralstonia), indicating its usefulness for intraspecific genotyping. The taxonomic discriminatory power of recN gene sequence was found to be superior to ribosomal DNA sequences. In all, the recN-sequence-based phylogenetic tree generated with the Bayesian model depicted 21 haplotypes against 15 and 13 haplotypes obtained with 16S rDNA and 16-23S rDNA intergenic sequences, respectively. Besides this, we have observed high percentage of polymorphic sites (S 23.04%), high rate of mutations (Eta 276) and high codon bias index (CBI 0.60), which makes the recN an ideal gene candidate for intraspecific molecular typing of this important plant pathogen.

  18. Optimisation of 16S rDNA amplicon sequencing protocols for microbial community profiling of anaerobic digesters

    DEFF Research Database (Denmark)

    Kirkegaard, Rasmus Hansen; McIlroy, Simon Jon; Larsen, Poul;

    of the community composition. As such sample specific optimisation and standardisation of DNA extraction, as well PCR primer selection, are essential to minimising the potential for such biases. The aim of this study was to develop a protocol for optimized community profiling of anaerobic digesters. The FastDNA......RNA gene amplicon sequencing is rapid, cheap, high throughput, and has high taxonomic resolution. However, biases are introduced in multiple steps of this approach, including non-representative DNA extraction and uneven taxonomic coverage of selected PCR primers, potentially giving a skewed view...... SPIN kit was selected and the mechanical lysis parameters optimised for extraction of genomic DNA from mesophilic and thermophilic anaerobic digester samples. Different primer sets were compared for targeting the archaea and bacteria, both together and individually. Shotgun sequencing of a TruSeq PCR...

  19. Sponge-associated actinobacterial diversity: validation of the methods of actinobacterial DNA extraction and optimization of 16S rRNA gene amplification.

    Science.gov (United States)

    Yang, Qi; Franco, Christopher M M; Zhang, Wei

    2015-10-01

    Experiments were designed to validate the two common DNA extraction protocols (CTAB-based method and DNeasy Blood & Tissue Kit) used to effectively recover actinobacterial DNA from sponge samples in order to study the sponge-associated actinobacterial diversity. This was done by artificially spiking sponge samples with actinobacteria (spores, mycelia and a combination of the two). Our results demonstrated that both DNA extraction methods were effective in obtaining DNA from the sponge samples as well as the sponge samples spiked with different amounts of actinobacteria. However, it was noted that in the presence of the sponge, the bacterial 16S rRNA gene could not be amplified unless the combined DNA template was diluted. To test the hypothesis that the extracted sponge DNA contained inhibitors, dilutions of the DNA extracts were tested for six sponge species representing five orders. The results suggested that the inhibitors were co-extracted with the sponge DNA, and a high dilution of this DNA was required for the successful PCR amplification for most of the samples. The optimized PCR conditions, including primer selection, PCR reaction system and program optimization, further improved the PCR performance. However, no single PCR condition was found to be suitable for the diverse sponge samples using various primer sets. These results highlight for the first time that the DNA extraction methods used are effective in obtaining actinobacterial DNA and that the presence of inhibitors in the sponge DNA requires high dilution coupled with fine tuning of the PCR conditions to achieve success in the study of sponge-associated actinobacterial diversity.

  20. Simultaneous DNA-RNA Extraction from Coastal Sediments and Quantification of 16S rRNA Genes and Transcripts by Real-time PCR.

    Science.gov (United States)

    Tatti, Enrico; McKew, Boyd A; Whitby, Corrine; Smith, Cindy J

    2016-06-11

    Real Time Polymerase Chain Reaction also known as quantitative PCR (q-PCR) is a widely used tool in microbial ecology to quantify gene abundances of taxonomic and functional groups in environmental samples. Used in combination with a reverse transcriptase reaction (RT-q-PCR), it can also be employed to quantify gene transcripts. q-PCR makes use of highly sensitive fluorescent detection chemistries that allow quantification of PCR amplicons during the exponential phase of the reaction. Therefore, the biases associated with 'end-point' PCR detected in the plateau phase of the PCR reaction are avoided. A protocol to quantify bacterial 16S rRNA genes and transcripts from coastal sediments via real-time PCR is provided. First, a method for the co-extraction of DNA and RNA from coastal sediments, including the additional steps required for the preparation of DNA-free RNA, is outlined. Second, a step-by-step guide for the quantification of 16S rRNA genes and transcripts from the extracted nucleic acids via q-PCR and RT-q-PCR is outlined. This includes details for the construction of DNA and RNA standard curves. Key considerations for the use of RT-q-PCR assays in microbial ecology are included.

  1. Vertical stratification of microbial communities in the Red Sea revealed by 16S rDNA pyrosequencing

    KAUST Repository

    Qian, Peiyuan

    2010-07-29

    The ecosystems of the Red Sea are among the least-explored microbial habitats in the marine environment. In this study, we investigated the microbial communities in the water column overlying the Atlantis II Deep and Discovery Deep in the Red Sea. Taxonomic classification of pyrosequencing reads of the 16S rRNA gene amplicons showed vertical stratification of microbial diversity from the surface water to 1500 m below the surface. Significant differences in both bacterial and archaeal diversity were observed in the upper (2 and 50 m) and deeper layers (200 and 1500 m). There were no obvious differences in community structure at the same depth for the two sampling stations. The bacterial community in the upper layer was dominated by Cyanobacteria whereas the deeper layer harbored a large proportion of Proteobacteria. Among Archaea, Euryarchaeota, especially Halobacteriales, were dominant in the upper layer but diminished drastically in the deeper layer where Desulfurococcales belonging to Crenarchaeota became the dominant group. The results of our study indicate that the microbial communities sampled in this study are different from those identified in water column in other parts of the world. The depth-wise compositional variation in the microbial communities is attributable to their adaptations to the various environments in the Red Sea. © 2011 International Society for Microbial Ecology All rights reserved.

  2. Phylogeny of the true water bugs (Nepomorpha: Hemiptera–Heteroptera) based on 16S and 28S rDNA and morphology

    DEFF Research Database (Denmark)

    Hebsgaard, Martin Bay; Andersen, Nils M.; Damgaard, Jakob

    2004-01-01

    the infraorders Gerromorpha and Leptopodomorpha. The morphological data matrix consisted of sixty-five characters obtained from literature sources. Molecular data included approximately 960 bp from the mitochondrial gene 16S and the nuclear gene 28S for all forty-two terminal taxa. The morphological dataset...... was analysed using maximum parsimony and the combined morphological and molecular (16S + 28S rDNA) dataset was analysed using direct optimization. A sensitivity analysis of sixteen different sets of parameters (various combinations of insertion-deletion cost and transversion costs) was undertaken. Character...

  3. Gastrointestinal Bacterial and Methanogenic Archaea Diversity Dynamics Associated with Condensed Tannin-Containing Pine Bark Diet in Goats Using 16S rDNA Amplicon Pyrosequencing

    OpenAIRE

    Min, Byeng R.; Sandra Solaiman; Raymon Shange; Jong-Su Eun

    2014-01-01

    Eighteen Kiko-cross meat goats (n=6) were used to collect gastrointestinal (GI) bacteria and methanogenic archaea for diversity measures when fed condensed tannin-containing pine bark (PB). Three dietary treatments were tested: control diet (0% PB and 30% wheat straw (WS); 0.17% condensed tannins (CT) dry matter (DM)); 15% PB and 15% WS (1.6% CT DM), and 30% PB and 0% WS (3.2% CT DM). A 16S rDNA bacterial tag-encoded FLX amplicon pyrosequencing technique was used to characterize and elucida...

  4. Polygenic analysis of ammonia-oxidizing bacteria using 16S rDNA, amoA, and amoB genes

    OpenAIRE

    Calvó Perxas, Laia; Cortey Marqués, Martí; García Marín, José Luis; Garcia-Gil, L. J.

    2005-01-01

    Finding a unique molecular marker capable of quickly providing rigorous and useful phylogenetic information would facilitate assessing the diversity of ammonia-oxidizing bacteria in environmental samples. Since only one of several available markers can be used at a time in these kinds of studies, the 16S rDNA, amoA and amoB genes were evaluated individually and then compared in order to identify the one that best fits the information provided by the composite dataset. Distance-based neighbor-...

  5. Sequence length variation of internal genic space of 16S rDNA-23S rDNA in biohydrogen-bacterium%产氢菌的16S -23S rDNA间隔区的长度变异性分析

    Institute of Scientific and Technical Information of China (English)

    李永峰; 郑国香; 张文启; 李建政; 胡立杰

    2005-01-01

    生物制氢细菌Rennanqilyf3的16S rRNA gene (rDNA)-23S rDNA间隔区碱基序列被测定.利用PCR扩增间隔区DNA,间隔区碱基序列存在长度多态现象.用这一长度多态现象进行产氢发酵细菌的辨认和识别.产氢发酵细菌Rennanqilyf3的16S rRNA gene (rDNA)-23S rDNA间隔区的PCR产品从1 270 到398 bp,共有5个序列.碱基数目分别为1 270、398、638、437 和 436 bp.%A method based on PCR amplification of the 16S rRNA gene (rDNA)-23S rDNA intergenic regions was developed for the identification of species for fermentative biohydrogen-producing bacterium. The sizes of the PCR products varied from 1 270 to 398 bp. Strain of Rennanqilyf3 were characterized as having products of 1 270,398,638, 437 and 436bp.

  6. Diversity and Recombination of Dispersed Ribosomal DNA and Protein Coding Genes in Microsporidia

    OpenAIRE

    Ironside, Joseph Edward

    2013-01-01

    Microsporidian strains are usually classified on the basis of their ribosomal DNA (rDNA) sequences. Although rDNA occurs as multiple copies, in most non-microsporidian species copies within a genome occur as tandem arrays and are homogenised by concerted evolution. In contrast, microsporidian rDNA units are dispersed throughout the genome in some species, and on this basis are predicted to undergo reduced concerted evolution. Furthermore many microsporidian species appear to be asexual and sh...

  7. Visualization of interaction between ribosome-inactivating proteins and supercoiled DNA with an atomic force microscope

    Institute of Scientific and Technical Information of China (English)

    吴晓华; 刘望夷; 欧阳振乾; 李民乾

    1997-01-01

    The interaction between ribosome-inactivating proteins (RIPs) and supercoiled DNA was observed with an atomic force microscope (AFM). It was found that RIPs can bind to both supercoiled DNA and the unwound double stranded loop region in supercoiled DNA. The RIPs hound to the supercoils can induce the conformational change of supercoiled DNA. Furthermore, the supercoiled DNA was relaxed and cleaved into nick or linear form by RIPs. It indicated that RIP seemed to be a supercoil-dependent DNA binding protein and exhibited the activity of su-percoil-dependent DNA endonuclease.

  8. Genomic-based restriction enzyme selection for specific detection of Piscirickettsia salmonis by 16S rDNA PCR-RFLP

    Directory of Open Access Journals (Sweden)

    Dinka eMandakovic

    2016-05-01

    Full Text Available The gram negative facultative bacterium P. salmonis is the etiological agent of Salmonid Rickettsial Septicaemia (SRS, a severe disease that causes important economic losses in the global salmon farmer industry. Despite efforts to control this disease, the high frequency of new epizootic events indicate that the vaccine and antibiotics treatments have limited effectiveness, therefore the preventive and diagnostic approaches must be improved. A comparison of several methodologies for SRS diagnostic indicate differences in their specificity and its capacity to detect other bacteria coexisting with P. salmonis in culture media (contamination and fish samples (coinfection, aspects relevant for research, vaccine development and clinical diagnostic. By computer-simulation analyses, we identified a group of restriction enzymes that generate unique P. salmonis 16S rDNA band patterns, distinguishable from all other bacteria. From this information, we designed and developed a PCR-RFLP (Polymerase Chain Reaction - Restriction Fragment Length Polymorphism assay, which was validated using 16S rDNA universal primers and restriction enzyme PmaCI for the amplification and digestion, respectively. Experimental validation was performed by comparing the restriction pattern of P. salmonis with the restriction patterns generated by bacteria that cohabit with P. salmonis (fish bacterial isolates and culture media contaminants. Our results indicate that the restriction enzyme selection pipeline was suitable to design a more specific, sensible, faster and cheaper assay than the currently used P. salmonis detection methodologies.

  9. Genomic-Based Restriction Enzyme Selection for Specific Detection of Piscirickettsia salmonis by 16S rDNA PCR-RFLP

    Science.gov (United States)

    Mandakovic, Dinka; Glasner, Benjamín; Maldonado, Jonathan; Aravena, Pamela; González, Mauricio; Cambiazo, Verónica; Pulgar, Rodrigo

    2016-01-01

    The gram negative facultative bacterium P. salmonis is the etiological agent of Salmonid Rickettsial Septicaemia (SRS), a severe disease that causes important economic losses in the global salmon farmer industry. Despite efforts to control this disease, the high frequency of new epizootic events indicate that the vaccine and antibiotics treatments have limited effectiveness, therefore the preventive and diagnostic approaches must be improved. A comparison of several methodologies for SRS diagnostic indicate differences in their specificity and its capacity to detect other bacteria coexisting with P. salmonis in culture media (contamination) and fish samples (coinfection), aspects relevant for research, vaccine development and clinical diagnostic. By computer-simulation analyses, we identified a group of restriction enzymes that generate unique P. salmonis 16S rDNA band patterns, distinguishable from all other bacteria. From this information, we designed and developed a PCR-RFLP (Polymerase Chain Reaction—Restriction Fragment Length Polymorphism) assay, which was validated using 16S rDNA universal primers and restriction enzyme PmaCI for the amplification and digestion, respectively. Experimental validation was performed by comparing the restriction pattern of P. salmonis with the restriction patterns generated by bacteria that cohabit with P. salmonis (fish bacterial isolates and culture media contaminants). Our results indicate that the restriction enzyme selection pipeline was suitable to design a more specific, sensible, faster and cheaper assay than the currently used P. salmonis detection methodologies. PMID:27242682

  10. Preliminary evaluation of the use of soil bacterial 16S rDNA DNA markers in sediment fingerprinting in two small endorheic lagoons in southern Spain

    Science.gov (United States)

    Gomez, Jose Alfonso; Landa del Castillo, Blanca; Guzman, Gema; Petticrew, Ellen L.; Owens, Phillip N.

    2016-04-01

    bulk community of DNA was extracted from 250 mg of soil samples (three replicates per sample) using the procedure described in Landa et al. (2014). The bacterial 16S rRNA gene V1-V2 hypervariable regions were amplified in polymerase chain reaction (PCR). The sequencing procedure was performed according to the manufacturer's recommendations using MiSeq Reagent Kit v2 for 300 cycles on MiSeq desktop sequencer. The raw dataset for each sample consisted of the number of counts for each of the 6640 operational taxonomic units (OTU) analyzed. All the screening and analysis was performed independently for each lagoon. Given the large number of OTUs, a first screening was made discarding any OTU that did not presented at least five samples with counts >20 for that OTU. This lowered the number of OTUs to 205 in Dulce and 217 in Zoñar. Because of the limited number of samples, we did not perform independent analysis for each soil depth. All the analyses were performed twice; one with the original number of counts and another with the normalized number of counts. We screened the OTU following a 4-step method to determine those with the best ability to discriminate among the three potential source areas. These steps were: 1) eliminate OTUs with no readings or very few, that could be experimental noise; 2) keep only OTUs that are different among source areas; 3) eliminate OTUs that range outside of feasible solutions to explain average values found in sediment; and 4) eliminate OTUs with the largest variability. Afterwards, several over-determined mixing models were solved considering different combinations of OTUs using limSolve (Soetaert et al., 2014) in R. Preliminary results show that 0.2 to 0.6 % of the searched OTUs (i.e. 14 to 42) had the potential for use in the mixing models after the four-step screening process. The results indicate a large variability in the number of counts among the samples from different areas within the subcatchments ranging, on average, from 49 to

  11. Phylogenetic Analysis of the 16S rDNA of a Strain Isolated from Diseased Larva of Anoplophora glabripennis (Motsch.)%罹病光肩星天牛幼虫分离菌株的16 S rDNA系统发育分析

    Institute of Scientific and Technical Information of China (English)

    邓彩萍; 刘红霞; 闫喜中; 武旭霞; 骆有庆

    2008-01-01

    [Objective] Study on the phylogenetic analysis of the 16S rDNA and insecticidal characteristics of strain BH-1 isolated from diseased larva of Anoplophora glabripennis (Motsch.) [Method] The strain was identified by routine method and inoculated onto healthy Anoplophora glabripennis (Motsch.) for observing insecticidal effect, further 16S DNA was amplified by the specific primers for sequencing and homology analysis. [Result] The mortality of second instar of Anoplophora glabripennis(Motsch.) reached 72.7% 8 d after 1010 cfu/ml BH-1 was inoculated. The homology of 16S DNA se- quences between BH-1 and Serratia marcescens accessed in GenBank reached 99.5%. Combined with the results of routine identification, BH-1 was identi-fied as S. marcescens. [Conclusion] BH-1 could be used for biological control ofAnoplophora glabripenais (Motsch.).

  12. Phylogenetic and characteristic analysis of 16S rDNA and rpoB gene sequence of Klebsiella%克雷伯菌16S rDNA和rpoB基因系统进化及序列特征分析

    Institute of Scientific and Technical Information of China (English)

    郭晓琳; 王多春; 阚飙; 张燕敏; 张怡; 左颖; 魏来; 高燕

    2009-01-01

    目的 比较分析克雷伯菌属的种之间16S rDNA和rpoB系统进化发育关系和序列进化特征.方法 选取经生化鉴定的克雷伯菌18株,提取菌株染色体作为模板,分别使用16S rDNA和rpoB通用引物扩增并测序16S rDNA和rpoB序列.与GenBank中目前已公布的8种克雷伯属菌株16S rDNA和rpoB序列各8条、除克雷伯菌外其他肠道菌株的16S rDNA和rpoB序列各9条一起,共计各35条16SrDNA和rpoB序列,在MEGA 4.0中建立进化树并进行分群分析,使用DNAStar/MegAlign程序比较分析8种克雷伯菌的种间16S rDNA和rpoB序列变异碱基位点,并做分歧度分析.结果 在所有受试的16SrDNA和rpoB的各35条序列中,16S rDNA和rpoB进化发育树都将克雷伯菌区分为3个群:分离的18株克雷伯菌中,15株肺炎亚种与GenBank中除产酸克雷伯菌和运动克雷伯菌外的其余6种克雷伯菌聚为一群(Ⅰ),其余3株克雷伯菌(FX246、FX280和FX286),经生化鉴定为产酸克雷伯菌,与GenBank中产酸克雷伯菌(DQ835530)聚为一群(Ⅱ);而GenBank中的运动克雷伯菌单独聚为一群(Ⅲ);进一步的分析,在rpoB进化发育树中,无沦足Ⅰ群和Ⅱ群,还足Ⅰ群内的两个亚群,rpoB进化发育树的结点处自引导值都明显高于16S rDNA进化发育树;而且rpoB对产酸克雷伯菌的分群优于16S rDNA.对克雷伯菌的序列分析发现,16S rDNA序列存在41个碱基变异位点,有4个易变区,rpoB序列存在63个碱基变异位点,有1个易变区;克雷伯菌16S rDNA和rpoB的相似性分别为95.9%~100%和90.2%~100%.进一步的克雷伯菌种间序列分歧值分析,rpoB分歧值(0~10.6)高于16S rDNA(0~4.0).结论 克雷伯菌rpoB比16S rDNA具有更高的分歧度,在克雷伯菌属内种的分子分类和鉴定中,rpoB比16S rDNA基因更具优越性.%Objective To compare and analyze the phylogenetic tree and sequence variant characteristics of Klebsiella species between 16S rDNA and rpoB. Methods Eighteen isolates

  13. Transfection of mouse ribosomal DNA into rat cells: faithful transcription and processing.

    OpenAIRE

    Vance, V B; Thompson, E A; Bowman, L H

    1985-01-01

    Truncated mouse ribosomal DNA (rDNA) genes were stably incorporated into rat HTC-5 cells by DNA-mediated cell transfection techniques. The mouse rDNA genes were accurately transcribed in these rat cells indicating that there is no absolute species specificity of rDNA transcription between mouse and rat. No more than 170 nucleotides of the 5' nontranscribed spacer was required for the accurate initiation of mouse rDNA transcription in rat cells. Further, the mouse transcripts were accurately c...

  14. Identification of Lactic Acid Bacteria Ⅱ 32 by Sequence Analysis of 16S rDNA and RecA - gene%16S rDNA和recA-gene对乳酸菌Ⅱ32的鉴定

    Institute of Scientific and Technical Information of China (English)

    刘长建; 权春善; 范圣第

    2007-01-01

    对乳酸菌Ⅱ32进行了生化实验.以菌株Ⅱ32的总DNA为模板,采用细菌通用的引物,对其16S rDNA进行特异扩增,并进行序列测定,将测定结果与GenBank DNA数据库中已知菌种的16S rDNA序列通过BLAST软件进行分析比较,初步确定该菌株为戊糖乳酸菌、植物乳杆菌或类植物乳杆菌.采用recA-gene约300bp的特异扩增片段最终确定乳酸菌Ⅱ32为类植物乳杆菌.

  15. Sequence analysis of the ribosomal DNA ITS2 region in two Trichogramma species (Hymenoptera: Trichogrammatidae

    Directory of Open Access Journals (Sweden)

    Ercan Sumer Fahriye

    2011-01-01

    Full Text Available Two egg parasitoid wasps, Trichogramma euproctidis (Girault and Trichogramma brassicae (Bezdenko (Hymenoptera: Trichogrammatidae were identified in the study. The taxonomy of these wasps is problematic because of their small size and lack of distinguishable morphological characters. The DNA sequence variation from the internal transcribed spacer 2 (ITS2 region of nuclear ribosomal DNA (rDNA was analyzed from these two Trichogramma species. This technique provides quick, simple and reliable molecular identification of Trichogramma species.

  16. The impact of different DNA extraction kits and laboratories upon the assessment of human gut microbiota composition by 16S rRNA gene sequencing.

    Directory of Open Access Journals (Sweden)

    Nicholas A Kennedy

    Full Text Available Determining bacterial community structure in fecal samples through DNA sequencing is an important facet of intestinal health research. The impact of different commercially available DNA extraction kits upon bacterial community structures has received relatively little attention. The aim of this study was to analyze bacterial communities in volunteer and inflammatory bowel disease (IBD patient fecal samples extracted using widely used DNA extraction kits in established gastrointestinal research laboratories.Fecal samples from two healthy volunteers (H3 and H4 and two relapsing IBD patients (I1 and I2 were investigated. DNA extraction was undertaken using MoBio Powersoil and MP Biomedicals FastDNA SPIN Kit for Soil DNA extraction kits. PCR amplification for pyrosequencing of bacterial 16S rRNA genes was performed in both laboratories on all samples. Hierarchical clustering of sequencing data was done using the Yue and Clayton similarity coefficient.DNA extracted using the FastDNA kit and the MoBio kit gave median DNA concentrations of 475 (interquartile range 228-561 and 22 (IQR 9-36 ng/µL respectively (p<0.0001. Hierarchical clustering of sequence data by Yue and Clayton coefficient revealed four clusters. Samples from individuals H3 and I2 clustered by patient; however, samples from patient I1 extracted with the MoBio kit clustered with samples from patient H4 rather than the other I1 samples. Linear modelling on relative abundance of common bacterial families revealed significant differences between kits; samples extracted with MoBio Powersoil showed significantly increased Bacteroidaceae, Ruminococcaceae and Porphyromonadaceae, and lower Enterobacteriaceae, Lachnospiraceae, Clostridiaceae, and Erysipelotrichaceae (p<0.05.This study demonstrates significant differences in DNA yield and bacterial DNA composition when comparing DNA extracted from the same fecal sample with different extraction kits. This highlights the importance of ensuring

  17. Genetic divergences of South and Southeast Asian frogs: a case study of several taxa based on 16S ribosomal RNA gene data with notes on the generic name Fejervarya

    OpenAIRE

    Hasan, Mahmudul; Islam, Mohammed Mafizul; KHAN, Md. Mukhlesur Rahman; Igawa, Takeshi; ALAM, Mohammad Shafiqul

    2014-01-01

    To elucidate the genetic divergences of several Asian frog taxa, the mitochondrial 16S rRNA gene (16S) sequences of 81 populations across 6 Asian countries were analyzed. In total, 109 haplotypes were found, and the concept of a 3% difference in 16S sequence corresponding to species threshold was applied to define candidate amphibian species, for which corroborating evidence, such as morphology, ecological characteristics, and/or nuclear gene data, is required. Polypedates leucomystax, Hylara...

  18. Bacterial 16S rDNA sequence analysis of Siberian tiger faecal flora%东北虎粪细菌区系的16S rRNA基因序列分析

    Institute of Scientific and Technical Information of China (English)

    图雅; 朱伟云; 陆承平

    2005-01-01

    为研究东北虎粪微生物区系建立了东北虎粪细菌的16S rDNA文库.通过EcoRⅠ和HindⅢ分别对阳性克隆进行酶切分析,从东北虎的16S rDNA文库中分别获得了15个具有酶切差异的克隆.BLAST分析结果显示,在15个克隆中,10个克隆与梭菌属成员有97%以上的同源性,其中有6个序列与诺维梭菌A型(Clostridium novyi type A)有99%的同源性,为诺维梭菌A型;4个序列与猪粪细菌RT-18B(Swine manure bacterium RT-18B)有97%的同源性,为消化链球菌属(Peptostreptococcus)成员.其它序列与GenBank中登录的序列同源性低于97%,为5种未培养细菌,其中4种16S rRNA基因序列分别与Clostridium pascui 、破伤风梭菌E88(Clostridium tetani E88)、梭菌(Clostridium sp.)14505及产气荚膜梭菌(Clostridiumperfringens)有94%~95%的相似性.第5种与肉杆菌(Carnobacterium sp.)R-7279株有94%的同源性.

  19. 16S rDNA测序快速鉴定废水生物处理系统目标细菌%Use of 16S rDNA sequencing for quickly determining target bacteria in biological wastewater treatment system

    Institute of Scientific and Technical Information of China (English)

    李永峰; 任南琪; 杨传平; 陈瑛; 郑国香; 胡立杰

    2005-01-01

    在废水生物处理系统中建立分子生物学技术快速鉴定有关微生物,具有十分重要的意义.以发酵法生物制氢系统的活性污泥分离培养的厌氧发酵细菌为研究对象,采用16S rDNA碱基测序分子生物学技术,通过生物信息学数据库NCBI将DNA序列输入、比对,可以直接鉴定从废水生物处理系统中分离培养的细菌进行种属科的系统发育学地位的判定,从而简化了细菌鉴定程序.通过16S rDNA测序技术,进行了分离产氢细菌的分子生物学鉴定,发现生物制氢厌氧活性污泥中所分离的细菌可能存在的菌属有:Lactobacillus,Clostridium,Klebsiella,Propionibacterium和可能新发现的1个新属Biohydrogenbacterium等5个菌属的菌种,其中新属Biohydrogenbacterium的菌种都以利用碳水化合物生产氢气为其主要特征.16S rDNA测序技术为废水生物处理系统的细菌学研究提供了方便、准确和经济的技术基础.

  20. Extraction of ribosomal RNA and genomic DNA from soil for studying the diversity of the indigenous bacterial community

    NARCIS (Netherlands)

    Duarte, G.F.; Rosado, A.S.; Keijzer-Wolters, A.C.; Elsas, van J.D.

    1998-01-01

    A method for the indirect (cell extraction followed by nucleic acid extraction) isolation of bacterial ribosomal RNA (rRNA) and genomic DNA from soil was developed. The protocol allowed for the rapid parallel extraction of genomic DNA as well as small and large ribosomal subunit RNA from four soils

  1. PCR assay based on DNA coding for 16S rRNA for detection and identification of mycobacteria in clinical samples.

    Science.gov (United States)

    Kox, L F; van Leeuwen, J; Knijper, S; Jansen, H M; Kolk, A H

    1995-01-01

    A PCR and a reverse cross blot hybridization assay were developed for the detection and identification of mycobacteria in clinical samples. The PCR amplifies a part of the DNA coding for 16S rRNA with a set of primers that is specific for the genus Mycobacterium and that flanks species-specific sequences within the genes coding for 16S rRNA. The PCR product is analyzed in a reverse cross blot hybridization assay with probes specific for M. tuberculosis complex (pTub1), M. avium (pAvi3), M. intracellulare (pInt5 and pInt7), M. kansasii complex-M. scrofulaceum complex (pKan1), M. xenopi (pXen1), M. fortuitum (pFor1), M. smegmatis (pSme1), and Mycobacterium spp. (pMyc5a). The PCR assay can detect 10 fg of DNA, the equivalent of two mycobacteria. The specificities of the probes were tested with 108 mycobacterial strains (33 species) and 31 nonmycobacterial strains (of 17 genera). The probes pAvi3, pInt5, pInt7, pKan1, pXen1, and pMyc5a were specific. With probes pTub1, pFor1, and pSme1, slight cross hybridization occurred. However, the mycobacterial strains from which the cross-hybridizing PCR products were derived belonged to nonpathogenic or nonopportunistic species which do not occur in clinical samples. The test was used on 31 different clinical specimens obtained from patients suspected of having mycobacterial disease, including a patient with a double mycobacterial infection. The samples included sputum, bronchoalveolar lavage, tissue biopsy samples, cerebrospinal fluid, pus, peritoneal fluid, pleural fluid, and blood. The results of the PCR assay agreed with those of conventional identification methods or with clinical data, showing that the test can be used for the direct and rapid detection and identification of mycobacteria in clinical samples. PMID:8586707

  2. Effects of DNA extraction and universal primers on 16S rRNA gene-based DGGE analysis of a bacterial community from fish farming water

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Among many reports investigating microbial diversity from environmental samples with denaturing gradient gel electrophoresis (DGGE), limited attention has been given to the effects of universal primers and DNA extraction on the outcome of DGGE analysis. In this study, these effects were tested with 16S rRNA gene-based DGGE on a bacterial community from farming water samples. The results indicate that the number of discernable bands in the DGGE fingerprint differed with the primer pairs used; the bands produced by 63f/518r, 341f/926r and 933f/1387r primer pairs were obviously fewer than those by 968f/1401r. Also, we found that each DNA extraction method resulted in different community profiles, reflected by the number and intensity of bands in the DGGE fingerprint. Furthermore,the main bands (theoretically representing dominant bacteria) differed with the extraction methods applied.It is therefore believed that the effects of universal primers and DNA extraction should be given more attention and carefully chosen before performing an investigation into a new environment with DGGE.

  3. 16S rDNA PCR-RFLP analysis and phylogeny of bacteria isolated from swamp and meadow aeolian soils in the Zoige Plateau, Sichuan, China%若尔盖高原沼泽土和草甸风沙土细菌16S rDNA PCR-RFLP和系统发育分析

    Institute of Scientific and Technical Information of China (English)

    张可; 陈强; 赵珂; 王文跃; 朱雪梅

    2010-01-01

    采用稀释平板法从若尔盖高原沼泽土和草甸风沙土分离获得66株细菌,在16S rDNA PCR-RFLP分析的基础上,测定了22株代表菌株的16S rDNA序列,构建了供试细菌的系统发育关系.16S rDNA PCR-RFLP分析中,在78%相似性水平处,除REG14,REG20,REG22和REG55单独成群外,其余菌株分为8个遗传群,其中,群Ⅰ和群Ⅳ最大,均有15个菌株,其次是群Ⅷ,由11个菌株组成,其余21个菌株分布于5个群内.对22个代表菌株16S rDNA全序列系统发育表明,这些菌株分布于不同的系统发育分支.其中,以芽孢杆菌属(Bacillus)、假单胞菌属(Pseudomonas)和分枝杆菌属(Mycobacterium)为主,其余菌株分布于Lysinibacillus属、中华根瘤菌属(Sinorhizobium)、不动杆菌(Acinetobacter)、固氮菌属(Azotobacter)、红球菌属(Rhodococcus)、微球菌属(Micrococcus)和醋酸杆菌属(Acetobacter)等7个属.

  4. Ribosomal and Mitochondrial DNA Analyses of Xiphinema americanum-Group Populations.

    Science.gov (United States)

    Lazarova, Stela S; Malloch, Gaynor; Oliveira, Claudio M G; Hübschen, Judith; Neilson, Roy

    2006-12-01

    The 18S ribosomal DNA (rDNA) and cytochrome oxidase I region of mitochondrial DNA (mtDNA) were sequenced for 24 Xiphinema americanum-group populations sourced from a number of geographically disparate locations. Sequences were subjected to phylogenetic analysis and compared. 18S rDNA strongly suggested that only X. pachtaicum, X. simile (two populations) and a X. americanum s.l. population from Portugal were different from the other 20 populations studied, whereas mtDNA indicated some heterogeneity between populations. Phylogenetically, based on mtDNA, an apparent dichotomy existed amongst X. americanum-group populations from North America and those from Asia, South America and Oceania. Analyses of 18S rDNA and mtDNA sequences underpin the classical taxonomic issues of the X. americanum-group and cast doubt on the degree of speciation within the X. americanum-group.

  5. The NBS1-Treacle complex controls ribosomal RNA transcription in response to DNA damage

    DEFF Research Database (Denmark)

    Larsen, Dorthe H; Hari, Flurina; Clapperton, Julie A;

    2014-01-01

    recruitment of the Nijmegen breakage syndrome protein 1 (NBS1), a central regulator of DNA damage responses, into the nucleoli. We further identify TCOF1 (also known as Treacle), a nucleolar factor implicated in ribosome biogenesis and mutated in Treacher Collins syndrome, as an interaction partner of NBS1...

  6. Ribosomal PCR and DNA sequencing for detection and identification of bacteria

    DEFF Research Database (Denmark)

    Jensen, Kristine Helander; Dargis, Rimtas; Christensen, Jens Jørgen;

    2014-01-01

    non-haemolytic streptococci, especially within the mitis group. The data show that ribosomal PCR with subsequent DNA sequencing of the PCR product is a most valuable supplement to culture for identifying bacterial agents of both acute and prolonged infections. However, some bacteria, including non...

  7. Studies on the Application of 16s rDNA for Rapid Detection of Streptoccocus Group C%利用16S rDNA快速鉴定C群链球菌的研究

    Institute of Scientific and Technical Information of China (English)

    王伟伟; 陈义平; 张喜悦; 赵永刚; 刘春菊; 王志亮

    2007-01-01

    本试验应用PCR方法,根据16S rDNA两端的保守序列,用prmer5.0软件设计引物扩增待检细菌,然后对扩增产物DNA片段进行测序、序列分析,经与GenBank中的已知序列进行同源性比较后,发现该未知菌属于链球菌C群.该方法比传统的细菌鉴定方法省时省力,并且能将细菌定型到群,结果准确、快速、重复性好.

  8. Natural variation in DNA methylation in ribosomal RNA genes of Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Richards Eric J

    2008-09-01

    Full Text Available Abstract Background DNA methylation is an important biochemical mark that silences repetitive sequences, such as transposons, and reinforces epigenetic gene expression states. An important class of repetitive genes under epigenetic control in eukaryotic genomes encodes ribosomal RNA (rRNA transcripts. The ribosomal genes coding for the 45S rRNA precursor of the three largest eukaryotic ribosomal RNAs (18S, 5.8S, and 25–28S are found in nucleolus organizer regions (NORs, comprised of hundreds to thousands of repeats, only some of which are expressed in any given cell. An epigenetic switch, mediated by DNA methylation and histone modification, turns rRNA genes on and off. However, little is known about the mechanisms that specify and maintain the patterns of NOR DNA methylation. Results Here, we explored the extent of naturally-occurring variation in NOR DNA methylation among accessions of the flowering plant Arabidopsis thaliana. DNA methylation in coding regions of rRNA genes was positively correlated with copy number of 45S rRNA gene and DNA methylation in the intergenic spacer regions. We investigated the inheritance of NOR DNA methylation patterns in natural accessions with hypomethylated NORs in inter-strain crosses and defined three different categories of inheritance in F1 hybrids. In addition, subsequent analysis of F2 segregation for NOR DNA methylation patterns uncovered different patterns of inheritance. We also revealed that NOR DNA methylation in the Arabidopsis accession Bor-4 is influenced by the vim1-1 (variant in methylation 1-1 mutation, but the primary effect is specified by the NORs themselves. Conclusion Our results indicate that the NORs themselves are the most significant determinants of natural variation in NOR DNA methylation. However, the inheritance of NOR DNA methylation suggests the operation of a diverse set of mechanisms, including inheritance of parental methylation patterns, reconfiguration of parental NOR DNA

  9. Diversity of Ulva spp.(Enteromorpha spp.) epiphytic bacteria based on 16S rDNA sequences%基于16S rDNA分析的浒苔外生细菌多样性研究

    Institute of Scientific and Technical Information of China (English)

    周新倩; 杨锐; 吴小凯; 黄艳花

    2016-01-01

    为研究浙江近海浒苔Ulva spp.(Enteromorpha spp.)外生细菌多样性,采用传统的形态学和16S rDNA测序分析的方法,从舟山朱家尖、宁海国华电厂和奉化南沙3个地区分离到可培养的浒苔外生细菌及其周围海水细菌65株.根据细菌菌落特征和革兰氏染色结果等将分离到的细菌分为26种表型.16S rDNA序列测序比对发现:菌株与不动杆菌属(Acinetobacter)、交替单胞菌属(Alteromonas)、弧菌属(Vibrio)、假交替单胞菌属(Pseudoalteromonas)、微小杆菌属(Exiguobacterium)、芽孢杆菌属(Bacillus)、赤细菌属(Erythrobacter)、微球菌属(Micrococcus)、假单胞菌属(Pseudomonas)、深海杆菌属(Idiomarina)、Phaeobacter、Roseivirgaj和Silicibacter等23个属相应菌株具有较高同源性.对不同地区浒苔外生细菌进行了Shannon-Wiener多样性指数分析.研究表明:(1)宁海国华电厂的浒苔外生细菌多样性最丰富,多样性指数为93.98%;(2)浒苔外生细菌与其生活地区密切相关,其群落组成具有地域差异,其优势类群也不尽相同,但均归属于变形菌门.

  10. Physiological and Biochemical Characteristics of Thermophilic Bacteria and Its 16S rDNA Sequence Analysis%高温菌的生理生化及其16S rDNA序列分析

    Institute of Scientific and Technical Information of China (English)

    李华芝; 李秀艳; 韩波波

    2010-01-01

    利用高温菌耐热嗜热的特性和有机物好氧分解的基本原理,从厨余垃圾处理系统中分离筛选到6株在65℃能产生淀粉酶、脂肪酶、蛋白质酶及纤维素酶的高温高效菌种,并对其生理生化和16S rDNA进行了分析.结果表明:筛选出的6株高温菌,经鉴定都有芽孢,并具有兼氧性;对其进行16S rDNA区段序列测定显示,6株高温菌属于Geobacillus thermoglucosidasius菌种中的不同亚种;分离筛选出的高温菌经过2h的迟缓期后很快进入对数生长期,且持续时间较长,生长速度尤以HB6最快;6株高温菌株全部具有淀粉、纤维素、蛋白质降解活性,5株有脂肪降解活性.可见高温菌具有更高的有机物降解活性和更快的代谢速率.可提高有机物质的降解速率,缩短工艺运行时间,有利于工业化生产,在厨余资源化利用上具有广泛的应用前景.

  11. Evolutionary Relationships among Three Belocera Species Inferred from 16 S rDNA Sequences%三种簇角飞虱属昆虫16 S rDNA序列及系统进化研究

    Institute of Scientific and Technical Information of China (English)

    侯晓晖; 陈祥盛

    2012-01-01

    通过PCR扩增获得了飞虱科3属5种昆虫的16 S rDNA序列,对DNA序列进行测定,分析了其序列组成及变异.采用Mega 4.0软件,利用邻接法(NJ)和最大简约法(MP)进行5种飞虱的系统发育分析,结果显示构建的MP和NJ分子系统树拓扑结构一致,3个簇角飞虱属物种中华簇角飞虱(Belocera.sinensis)、褐额簇角飞虱(B.fuscifrons)和爬竹簇角飞虱(B.ampelocalamus)单独聚为一支,与偏角飞虱属海南偏角飞虱(Neobelocera hainanensis)的亲缘关系较近,与短头飞虱属显脊短头飞虱(Epeurysa distincta)的亲缘关系较远,分子生物学分析结果与形态学研究结果一致.%The 16 S Rdna sequences of 5 plant hoppers belonging to 3 genus in the family of Delphacidae were obtained by PCR and then sequenced. The sequence composition and mutation were analyzed. Molecular phylogenetic trees were constructed by maximum parsimony method (MP) and neighbor-joining method (NJ) using Mega 4.0 software. The result showed that the topologies of MP tree and NJ tree constructed were the same. Belocera Sinensis, B. Juscifrons and B. Ampelocalamus were clustered into one group, which had closer relationship to Neobelocera hainanensis while further distance from Epeurysa dis-tincta. These results were identical with those of morphology research.

  12. Nucleolar Organization, Ribosomal DNA Array Stability, and Acrocentric Chromosome Integrity Are Linked to Telomere Function

    OpenAIRE

    Stimpson, Kaitlin M.; Sullivan, Lori L; Kuo, Molly E.; Sullivan, Beth A.

    2014-01-01

    The short arms of the ten acrocentric human chromosomes share several repetitive DNAs, including ribosomal RNA genes (rDNA). The rDNA arrays correspond to nucleolar organizing regions that coalesce each cell cycle to form the nucleolus. Telomere disruption by expressing a mutant version of telomere binding protein TRF2 (dnTRF2) causes non-random acrocentric fusions, as well as large-scale nucleolar defects. The mechanisms responsible for acrocentric chromosome sensitivity to dysfunctional tel...

  13. RFLP analysis of ribosomal DNA in sibling species of spider mite, genus Panonychus (Acari: Tetranychidae).

    Science.gov (United States)

    Osakabe, M; Sakagami, Y

    1994-02-01

    Ribosomal DNA (rDNA) restriction fragment length of spider mites was analysed in three sibling species of genus Panonychus (P. mori, P. citri and P. ulmi) and Tetranychus urticae. Seventy-one fragments were detected by enhanced chemiluminescence (ECL) after Southern hybridization with two genomic rDNA probes of mouse. Percentages of shared fragments within species were larger than those among species, indicating that the variation of rDNAs was useful in phylogenetic studies of spider mite species. In a phenogram based on differences of the rDNA fragment length, the relationship among Panonychus species was compatible with the results of analysis based on the morphological characters. PMID:7915173

  14. Evaluation of direct 16S rDNA sequencing as a metagenomics-based approach to screening bacteria in bottled water.

    Science.gov (United States)

    Hansen, Trine; Skånseng, Beate; Hoorfar, Jeffrey; Löfström, Charlotta

    2013-09-01

    Deliberate or accidental contamination of food, feed, and water supplies poses a threat to human health worldwide. A rapid and sensitive detection technique that could replace the current labor-intensive and time-consuming culture-based methods is highly desirable. In addition to species-specific assays, such as PCR, there is a need for generic methods to screen for unknown pathogenic microorganisms in samples. This work presents a metagenomics-based direct-sequencing approach for detecting unknown microorganisms, using Bacillus cereus (as a model organism for B. anthracis) in bottled water as an example. Total DNA extraction and 16S rDNA gene sequencing were used in combination with principle component analysis and multicurve resolution to study detection level and possibility for identification. Results showed a detection level of 10(5) to 10(6) CFU/L. Using this method, it was possible to separate 2 B. cereus strains by the principal component plot, despite the close sequence resemblance. A linear correlation between the artificial contamination level and the relative amount of the Bacillus artificial contaminant in the metagenome was observed, and a relative amount value above 0.5 confirmed the presence of Bacillus. The analysis also revealed that background flora in the bottled water varied between the different water types that were included in the study. This method has the potential to be adapted to other biological matrices and bacterial pathogens for fast screening of unknown bacterial threats in outbreak situations. PMID:23971801

  15. Evaluation of direct 16S rDNA sequencing as a metagenomics-based approach to screening bacteria in bottled water.

    Science.gov (United States)

    Hansen, Trine; Skånseng, Beate; Hoorfar, Jeffrey; Löfström, Charlotta

    2013-09-01

    Deliberate or accidental contamination of food, feed, and water supplies poses a threat to human health worldwide. A rapid and sensitive detection technique that could replace the current labor-intensive and time-consuming culture-based methods is highly desirable. In addition to species-specific assays, such as PCR, there is a need for generic methods to screen for unknown pathogenic microorganisms in samples. This work presents a metagenomics-based direct-sequencing approach for detecting unknown microorganisms, using Bacillus cereus (as a model organism for B. anthracis) in bottled water as an example. Total DNA extraction and 16S rDNA gene sequencing were used in combination with principle component analysis and multicurve resolution to study detection level and possibility for identification. Results showed a detection level of 10(5) to 10(6) CFU/L. Using this method, it was possible to separate 2 B. cereus strains by the principal component plot, despite the close sequence resemblance. A linear correlation between the artificial contamination level and the relative amount of the Bacillus artificial contaminant in the metagenome was observed, and a relative amount value above 0.5 confirmed the presence of Bacillus. The analysis also revealed that background flora in the bottled water varied between the different water types that were included in the study. This method has the potential to be adapted to other biological matrices and bacterial pathogens for fast screening of unknown bacterial threats in outbreak situations.

  16. Computational and Experimental Characterization of Ribosomal DNA and RNA G-Quadruplexes

    Science.gov (United States)

    Cho, Samuel

    DNA G-quadruplexes in human telomeres and gene promoters are being extensively studied for their role in controlling the growth of cancer cells. Recent studies strongly suggest that guanine (G)-rich genes encoding pre-ribosomal RNA (pre-rRNA) are a potential anticancer target through the inhibition of RNA polymerase I (Pol I) in ribosome biogenesis. However, the structures of ribosomal G-quadruplexes at atomic resolution are unknown, and very little biophysical characterization has been performed on them to date. Here, we have modeled two putative rDNA G-quadruplex structures, NUC 19P and NUC 23P, which we observe via circular dichroism (CD) spectroscopy to adopt a predominantly parallel topology, and their counterpart rRNA. To validate and refine the putative ribosomal G-quadruplex structures, we performed all-atom molecular dynamics (MD) simulations using the CHARMM36 force field in the presence and absence of stabilizing K + or Na + ions. We optimized the CHARMM36 force field K + parameters to be more consistent with quantum mechanical calculations (and the polarizable Drude model force field) so that the K + ion is predominantly in the G-quadruplex channel. Our MD simulations show that the rDNA G-quadruplex have more well-defined, predominantly parallel-topology structures than rRNA and NUC 19P is more structured than NUC 23P, which features extended loops. Our study demonstrates that they are both potential targets for the design of novel chemotherapeutics.

  17. Phylogenetic Analysis of Veneridae (Mollusca: Bivalvia) based on Mitochondrial 16S rDNA%基于16S rDNA序列的帘蛤科贝类分子系统发育研究

    Institute of Scientific and Technical Information of China (English)

    程汉良; 周旻纯; 陈冬勤; 彭永兴; 董志国; 易乐飞; 孟学平; 申欣

    2012-01-01

    对21种帘蛤科贝类线粒体16S rRNA基因片段的核苷酸序列进行了分析,以探讨这一序列在种质鉴定、分子系统发育研究中的应用价值.试验结果表明,所有物种扩增片段长度504~642 bp,具有明显的长度多态性,序列A+T含量59.2%~69.0%,明显高于GC含量.物种间共有变异位点447个,其中简约信息位点351个.以16S rDNA片段序列为标记,以中国蛤蜊做外群,构建了帘蛤科贝类的系统发生树,拓扑结构显示,帘蛤科贝类形成3个明显类群,缀锦蛤亚科的13个种形成一个单系群,其结点自展值为93%.第二类群由雪蛤亚科、帘蛤亚科和镜蛤亚科的种类组成,结点自展值为87%.第三类群由仙女蛤亚科、青蛤亚科、楔形蛤亚科和文蛤亚科的种类组成,结点自展值为100%.结合拓扑结构分析和序列比对分析,本研究支持将短文蛤和丽文蛤订为文蛤的同物异名的观点,建议将丽文蛤和短文蛤订为文蛤的地理亚种;支持将薄片镜蛤和Dosinia angulosa订为2个独立种的观点;宜将波纹巴非蛤和织锦巴非蛤订为2个独立种.

  18. Studies on biodegradation and molecular characterization of 2,4-D Ethyl Ester and Pencycuron induced Cyanobacteria by using GC-MS and 16S rDNA sequencing

    Directory of Open Access Journals (Sweden)

    J. I. Nirmal Kumar

    2013-03-01

    Full Text Available GC-MS study and molecular characterization by 16S rDNA amplification were carried out to evaluate differential effects of 2,4-D ethyl ester and pencycuron on Anabaena fertilissima, Aulosira fertilissima and Westiellopsis prolifica. Each organism has its own capacity to degrade both pesticides into various subgroups depending largely upon the main functional group of each individual pesticide. Hence, different subgroups like 2,4-D methyl ester, 2,4-D isobutyl ester, Isobutyric acid allyl ester, 3-Bromobutyric acid, 2,4-D butyl ester, Hydroxyurea, Trifluroacetic acid, 2-Methyl propyl ester, Acetic acid 2-propenyl ester and Acetic acid (2,3-dichlorophenoxy were transformed from 2,4-D ethyl ester while Benzoxazole was the only compound generated from pencycuron treated W. prolifica. The results obtained by 16S rDNA sequencing confirmed that 16S rDNA region of Anabaena fertilissima was more affected by 2,4-D ethyl ester as there was no homology in the region of 39 basepairs, in addition, several mismatches and gaps were observed, whereas less difference in 16S rDNA was observed in case of Aulosira fertilissima and W. prolific on forth day. However, there was no significant change in the sequence of 16S rDNA pattern of all the three test organisms after 16-days of exposure to pencycuron treatment.

  19. DNA sequencing reveals limited heterogeneity in the 16S rRNA gene from the rrnB operon among five Mycoplasma hominis isolates

    DEFF Research Database (Denmark)

    Mygind, T; Birkelund, Svend; Christiansen, Gunna

    1998-01-01

    To investigate the intraspecies heterogeneity within the 16S rRNA gene of Mycoplasma hominis, five isolates with diverse antigenic profiles, variable/identical P120 hypervariable domains, and different 16S rRNA gene RFLP patterns were analysed. The 16S rRNA gene from the rrnB operon was amplified...... by PCR and the PCR products were sequenced. Three isolates had identical 16S rRNA sequences and two isolates had sequences that differed from the others by only one nucleotide....

  20. Identification Lactic acid bacteria isolated from mongolia fermented milk products bases on 16S rDNA sequence analysis and tuf-RFLP technology%利用16S rDNA序列及tuf-RFLP鉴定蒙古国发酵乳中的乳酸菌

    Institute of Scientific and Technical Information of China (English)

    王宏梅; 于洁; 包秋华; 吕嫱; 孟和毕力格; 张和平

    2011-01-01

    One hundred and ten strains of lactic acid bacteria (LAB) isolated from twenty five samples of naturally fermented yoghurt in Dza-vhan of Mongolia were classified by 16S rDNA sequence analysis and tuf- RFLP. They were preliminary identified as Streptococcus thermophilus (41 strains), Lactobacillus helvetkus (40 strains), Lactobarillus delbrueckii subsp. Bulgaricus (11 strains), Lactobadllus fermentum (2 strains), Leuconostoc mesenteroides subsp. Mesenteroides (2 strains), Lactococcus lactis subsp. Lactis (1 strain) and Lactobadllus casei group (12 strains) by 16S rDNA sequence analysis. However, the 16S rDNA sequence of Lactobadllus casei group existed very small difference, tuf-RFLP was used to confirm results given by 16S rDNA sequencing. The tuf- RFLP profile pattern revealed that the twelve strains were accurately identified as Lactobadllus casei.%运用16S rDNA序列分析和tuf-RFLP技术对采于蒙古国扎布汗省的25份发酵乳样中分离出的110株乳酸菌进行鉴定.首先将分离的110株乳酸菌的16S rRNA基因进行扩增,测序并构建系统发育树,初步鉴定为41株嗜热链球菌,40株瑞士乳杆菌,11株德氏乳杆菌保加利亚亚种,2株发酵乳杆菌,1株乳明串珠菌,2株肠膜明串肠膜亚种,1株乳酸乳球乳酸亚种和12株属于干酪族的菌株.由于干酪乳杆菌族的16S rDNA序列差异很小,故采用tuf-RFLP 技术对这12株进行了进一步的验证,通过分离菌株与模式菌株tuf-RFLP图谱的比较分析,结果表明这12株菌均为干酪乳杆菌.

  1. Isolation of eukaryotic ribosomal proteins. Purification and characterization of the 40 S ribosomal subunit proteins Sa, Sc, S3a, S3b, S5', S9, S10, S11, S12, S14, S15, S15', S16, S17, S18, S19, S20, S21, S26, S27', and S29.

    Science.gov (United States)

    Collatz, E; Ulbrich, N; Tsurugi, K; Lightfoot, H N; MacKinlay, W; Lin, A; Wool, I G

    1977-12-25

    The proteins of the small subunit of rat liver ribosomes were separated into five main groups by stepwise elution from carboxymethylcellulose with LiCl at pH 6.5. Twenty-one proteins (Sa, Sc, S3a, S3b, S5', S9, S10, S11, S12, S14, S15, S15', S16, S17, S18, S19, S20, S21, S26, S27', and S29) were isolated from three groups (A40, C40, and D40) by ion exchange chromatography on DEAE-cellulose, carboxymethylcellulose, and phosphocellulose and by filtration through Sephadex. The amount of protein obtained varied from 0.1 to 11 mg. Six of the proteins (S5', S10, S11, S18, S19, and S27') had no detectable contamination; the impurities in the others were no greater than 9%. The molecular weight of the proteins was estimated by polyacrylamide gel electrophoresis in sodium dodecyl sulfate; the amino acid composition was determined.

  2. The evolutionary history of the genus Timarcha (Coleoptera, Chrysomelidae) inferred from mitochondrial COII gene and partial 16S rDNA sequences.

    Science.gov (United States)

    Gómez-Zurita, J; Juan, C; Petitpierre, E

    2000-02-01

    The apterous genus Timarcha consists of three subgenera and more than 100 species in its Palearctic distribution, with specialized feeding on few plant families. Fifty-four sequences sampled from 31 taxa of the genus plus three outgroup leaf beetles were studied for their complete cytochrome oxidase II (COII) and a fragment of 16S rDNA mitochondrial genes, representing a total of about 1200 bp. Phylogenetic analyses using maximum-parsimony and distance methods for each gene separately and for the combined data set gave compatible topologies. The subgenus Metallotimarcha consistently appears in a basal position and is well differentiated from the remaining Timarcha, but no clear monophyletic grouping of Timarchostoma and Timarcha s. str. subgenera can be deduced from our analysis. Calibration of the molecular clock has been done using the opening of the Gibraltar Strait after the Messinian salinity crisis (about 5.5 MYA) as the biogeographic event causing disjunction of two particular taxa. Accordingly, the COII evolutionary rate has been estimated to be of 0.76 x 10(-8) substitution/site/year in Timarcha. Relation between phylogeny and host-plant use indicates widening of trophic regime as a derived character in Timarcha. PMID:10679162

  3. Community analysis of ammonia oxidizer in the oxygen-limited nitritation stage of OLAND system by DGGE of PCR amplified 16S rDNA Fragments and FISH

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dan; ZHANG De-min; LIU Yao-ping; CAO Wen-wei; CHEN Guan-xiong

    2004-01-01

    OLAND(oxygen limited autotrophic nitrification and denitrification) nitrogen removal system was constructed by coupling with oxygen limited nitritation stage and anaerobic ammonium oxidation stage. Ammonia oxidizer, as a kind of key bacteria in N cycle, plays an important role at the oxygen limited nitritation stage of OLAND nitrogen removal system. In this study, specific amplification of 16S rDNA fragment of ammonia oxidizer by nested PCR, separation of mixed PCR samples by denaturing gradient gel electrophoresis(DGGE), and the quantification of ammonia oxidizer by Fluorescence in situ hybridization(FISH) were combined to investigate the shifts of community composition and quantity of ammonia oxidizer of the oxygen limited nitritation stage in OLAND system. It showed that the community composition of ammonia oxidizer changed drastically when dissolved oxygen was decreased gradually, and the dominant ammonia oxidizer of the steady nitrite accumulation stage were completely different from that of the early stage of oxygen limited nitritation identified by DGGE . It was concluded that the Nitrosomonas may be the dominant genus of ammonia oxidizer at the oxygen limited nitritation stage of OLAND system characterized by nested PCR-DGGE and FISH, and the percentage of Nitrosomonas was 72.5% ( 0.8% of ammonia oxidizer at the steady nitrite accumulation stage detected by FISH.

  4. Gastrointestinal Bacterial and Methanogenic Archaea Diversity Dynamics Associated with Condensed Tannin-Containing Pine Bark Diet in Goats Using 16S rDNA Amplicon Pyrosequencing

    Directory of Open Access Journals (Sweden)

    Byeng R. Min

    2014-01-01

    Full Text Available Eighteen Kiko-cross meat goats (n=6 were used to collect gastrointestinal (GI bacteria and methanogenic archaea for diversity measures when fed condensed tannin-containing pine bark (PB. Three dietary treatments were tested: control diet (0% PB and 30% wheat straw (WS; 0.17% condensed tannins (CT dry matter (DM; 15% PB and 15% WS (1.6% CT DM, and 30% PB and 0% WS (3.2% CT DM. A 16S rDNA bacterial tag-encoded FLX amplicon pyrosequencing technique was used to characterize and elucidate changes in GI bacteria and methanogenic archaea diversity among the diets. Proteobacteria was the most dominant phylum in goats with mean relative abundance values ranging from 39.7 (30% PB to 46.5% (control and 47.1% (15% PB. Other phyla individually accounted for fewer than 25% of the relative abundance observed. Predominant methanogens were Methanobrevibacter (75, 72, and 49%, Methanosphaera (3.3, 2.3, and 3.4%, and Methanobacteriaceae (1.2, 0.6, and 0.7% population in control, 15, and 30% PB, respectively. Among methanogens, Methanobrevibacter was linearly decreased (P=0.05 with increasing PB supplementation. These results indicate that feeding PB selectively altered bacteria and methanogenic archaeal populations in the GI tract of goats.

  5. Cloning, Sequencing and Analysis of the 16S-23S rDNA Intergenic Spacers (IGSs) of Two Strains of Vibrio vulnificus%2株创伤弧菌的16S-23S rDNA间区的克隆、测序及分析

    Institute of Scientific and Technical Information of China (English)

    邓先余; 陈晓艳; 王智学; 欧普; 何建国

    2006-01-01

    根据细菌的16S rDNA 3'端和23S rDNA 5'端的高度保守区设计引物,PCR扩增了2株创伤弧菌(Vibrio vulnificus)的16S-23S rDNA间区(Intergenic spacer,IGS),克隆到pGEM-T载体上,测序.用BLAST和DNAstar软件对16S-23SrDNA间区序列及其内的tRNA基因进行比较分析.结果表明,2株创伤弧菌共测出9条16S-23S rDNA间区序列,其中ZSU006测出5条,间区类型分别为:IGSGLAV、IGSGLV、IGSIA、IGSA和IGSG.其中IGSGLAV最大,包含tRNAGlu、tRNALys、tRNAAla和tRNAVal基因;IGSGLV包含tRNAGlu、tRNALys和tRNAVal基因;IGSIn,则包含tRNAIle和tRNAAla基因;IGSG仅包含tRNAGlu基因;而IGSA仅包含tRNAAla基因.菌株CG021测出的16S-23S rDNAIGS序列有4条,除缺少IGSA外,其余的IGS类型均与ZSU006的相同.与GenBank内的创伤弧菌ATCC27562的IGS序列比较,发现创伤弧菌所有类型的IGS的tRNA基因两端的非编码区具有较高的种内同源性.16S-23S rDNA间区结构的差异为建立一种新的创伤弧菌检测方法奠定了基础.%According to the conserved sequences flanking the 3' end of the 16S and the 5' end of the 23S rDNAs, PCR primers were designed, and the 16S-23S rDNA intergenic spacers (IGSs) of two strains of Vibrio vulnificus were amplified by PCR and cloned into pGEM-T vector. Different clones were selected to be sequenced and the sequences were analyzed with BLAST and the software DNAstar. Analyses of the IGS sequences suggested that the strain ZSU006 contains five types of polymorphic16S-23S rDNA intergenic spacers, namely, IGSGLAV, IGSGLv, IGSIA, IGSG and IGSA; while the strain CG021 has the same types of IGSs except lacking IGSA. Among these five IGS types, IGSGLAV is the biggest type, including the gene cluster of tRNAGlu - tRNALys - tRNAAla - tRNAVal; IGSGLV includes that of tRNAGlu-tRNALys-tRNAVal; IGSAG, tRNAAla-tRNAGlu; IGSIA, tRNAIle -tRNAAla; IGSG, tRNAGlu and IGSA, tRNAAla. Intraspecies multiple alignment of all the IGS sequences of these two strains with those of V

  6. Ribosomal protein genes are overexpressed in colorectal cancer: isolation of a cDNA clone encoding the human S3 ribosomal protein.

    Science.gov (United States)

    Pogue-Geile, K; Geiser, J R; Shu, M; Miller, C; Wool, I G; Meisler, A I; Pipas, J M

    1991-08-01

    We have isolated a cDNA clone encoding the human S3 ribosomal protein from a normal human colon cDNA library. The clone was identified as one of many that detected genes whose level of expression was increased in adenocarcinoma of the colon relative to normal colonic mucosa. Increased levels of the S3 transcript were present in the tumors of all eight patients examined. Moreover, the S3 mRNA was also more abundant in 7 of 10 adenomatous polyps, the presumed precursor of carcinoma. Additional studies demonstrated that increased levels of mRNAs encoding several other ribosomal proteins, including S6, S8, S12, L5, and P0, were present in colorectal tumors and polyps. These results suggest that there is increased synthesis of ribosomes in colorectal tumors and that this increase is an early event in colon neoplasia.

  7. Evaluation of the effects of intrapartum antibiotic prophylaxis on newborn intestinal microbiota using a sequencing approach targeted to multi hypervariable 16S rDNA regions.

    Science.gov (United States)

    Aloisio, Irene; Quagliariello, Andrea; De Fanti, Sara; Luiselli, Donata; De Filippo, Carlotta; Albanese, Davide; Corvaglia, Luigi Tommaso; Faldella, Giacomo; Di Gioia, Diana

    2016-06-01

    Different factors are known to influence the early gut colonization in newborns, among them the perinatal use of antibiotics. On the other hand, the effect on the baby of the administration of antibiotics to the mother during labor, referred to as intrapartum antibiotic prophylaxis (IAP), has received less attention, although routinely used in group B Streptococcus positive women to prevent the infection in newborns. In this work, the fecal microbiota of neonates born to mothers receiving IAP and of control subjects were compared taking advantage for the first time of high-throughput DNA sequencing technology. Seven different 16S rDNA hypervariable regions (V2, V3, V4, V6 + V7, V8, and V9) were amplified and sequenced using the Ion Torrent Personal Genome Machine. The results obtained showed significant differences in the microbial composition of newborns born to mothers who had received IAP, with a lower abundance of Actinobacteria and Bacteroidetes as well as an overrepresentation of Proteobacteria. Considering that the seven hypervariable regions showed different discriminant ability in the taxonomic identification, further analyses were performed on the V4 region evidencing in IAP infants a reduced microbial richness and biodiversity, as well as a lower number of bacterial families with a predominance of Enterobacteriaceae members. In addition, this analysis pointed out a significant reduction in Bifidobacterium spp. strains. The reduced abundance of these beneficial microorganisms, together with the increased amount of potentially pathogenic bacteria, may suggest that IAP infants are more exposed to gastrointestinal or generally health disorders later in age. PMID:26971496

  8. Designing PCR Primers from 16S-23S rDNA Intergenic Spacer Region for the Identification of Pasteurella multocida%以 16S-23S rDNA 间区序列为目的基因设计 PCR 引物鉴定多杀巴斯德氏菌

    Institute of Scientific and Technical Information of China (English)

    周浩; 刘寅; 陈一军; 郑泽军; 黄熙泰

    2008-01-01

    多杀巴斯德氏菌是养殖动物(鸡,猪,牛等)的重要致病菌.本研究以16S-23S rDNA间区序列为目的基因设计PCR引物鉴定多杀巴斯德氏菌.通过对多杀巴斯德氏菌ITS-IA(含有tDNA-Ile和tDNA-Ala的16S-23S rDNA间区序列)的测序和与GenBank中序列的BLAST,设计筛选了一对特异引物PS-F/PS-R.对引物的特异性和有效性,用PCR方法进行了验证.结果表明:所有的多杀巴斯德氏菌标准菌株和分离菌株都能被检出,而全部39株非多杀巴斯德氏菌都没有扩增出特异性条带.其检测灵敏度能达到102CFU/mL.研究结果表明,发展了的PCR鉴定方法是省时的和可靠的,整个过程只需要20 h,而传统的鉴定方法需要至少5 d的时间.%Pasteurella multocida is an important pathogen that infects many kinds of animals. In present study, a polymerase chain reaction (PCR) assay using primers derived from the 16S-23S rRNA intergenic spacer (ITS) of P. multocida was developed. One pairs of specific PCR primers were designed by sequencing the ITS-IA (ITS containing tDNA-Ile and tDNA-Ala) of P. multocida and BLAST of GenBank. The specificity and efficiency of the PCR methods were tested against a panel of numerous strains from 39 different bacterial strains. All of the P. multocida strains generated positive signal, and no cross-reaction was observed with non-P, multocida strains in the PCR detection. Sensitivity of the detection is 102 CFU/mL cultures. The newly developed PCR array procedures take only 20 hours for each time, whereas the conventional methods required at least five days. This study demonstrated that the PCR detection for P. multocida is time-saved and reliable.

  9. Identification of Streptococcus species and Haemophilus influenzae by direct sequencing of PCR products from 16S-23SrDNA intergenic spacer regions%16S-23SrDNA间区序列在链球菌和流感嗜血杆菌分类的应用

    Institute of Scientific and Technical Information of China (English)

    鲁辛辛; 杨持; 黎琳; 杨宏欣

    2002-01-01

    Objective To set up a rapid and simple method for identificating bacteria by 16S-23SrDNA intergenic spacer regions (ISRs). Methods Polymorphic products of PCR from ISRs were selected on agarose gel and sequenced directly using purified fragments by excising the gel without cloning. Nucleotide sequences were compared with GenBank databases and analyzed by DNAMAN program.Results There was only a single product in streptococcus genus after PCR amplification of 16S-23SrDNA ISRs. Five streptococcal species were obtained from 7 strains of streptococcus. Two major amplicons were consistently generated for 8 strains of Haemophilus influenzae (H. influenzae). The sequence data showed that they all belonged to H. influenzae type b on GenBank databases.Conclusion PCR and direct sequencing of 16S-23SrDNA ISRs were very successful methods for bacterial species identification.%目的利用16S-23SrRNA间区的特征建立一种简单、快速的细菌分类方法.方法以化脓性链球菌16SrRNA的3'端和23SrRNA的5'端的保守区中合成3对引物,PCR扩增16S-23SrDNA ISRs,纯化后直接测序,在GenBank上查找对应细菌的ISRs序列.用DNAMAN软件进行系统进化分析.结果链球菌属为单拷贝16S-23SrRNA ISRs片段,编码1个tRNAAla基因.流感嗜血杆菌各生物型出现2个大小相似的ISRs片段.与GenBank上的资料比较,7株链球菌归属5个种,流感嗜血杆菌均为b型.结论 ISRs作为细菌分类新的目标基因具有属、种、型和株特异性与灵敏性.

  10. Nuclear ribosomal internal transcribed spacer (ITS) region as a universal DNA barcode marker for Fungi

    Science.gov (United States)

    Schoch, Conrad L.; Seifert, Keith A.; Huhndorf, Sabine; Robert, Vincent; Spouge, John L.; Levesque, C. André; Chen, Wen; Bolchacova, Elena; Voigt, Kerstin; Crous, Pedro W.; Miller, Andrew N.; Wingfield, Michael J.; Aime, M. Catherine; An, Kwang-Deuk; Bai, Feng-Yan; Barreto, Robert W.; Begerow, Dominik; Bergeron, Marie-Josée; Blackwell, Meredith; Boekhout, Teun; Bogale, Mesfin; Boonyuen, Nattawut; Burgaz, Ana R.; Buyck, Bart; Cai, Lei; Cai, Qing; Cardinali, G.; Chaverri, Priscila; Coppins, Brian J.; Crespo, Ana; Cubas, Paloma; Cummings, Craig; Damm, Ulrike; de Beer, Z. Wilhelm; de Hoog, G. Sybren; Del-Prado, Ruth; Dentinger, Bryn; Diéguez-Uribeondo, Javier; Divakar, Pradeep K.; Douglas, Brian; Dueñas, Margarita; Duong, Tuan A.; Eberhardt, Ursula; Edwards, Joan E.; Elshahed, Mostafa S.; Fliegerova, Katerina; Furtado, Manohar; García, Miguel A.; Ge, Zai-Wei; Griffith, Gareth W.; Griffiths, K.; Groenewald, Johannes Z.; Groenewald, Marizeth; Grube, Martin; Gryzenhout, Marieka; Guo, Liang-Dong; Hagen, Ferry; Hambleton, Sarah; Hamelin, Richard C.; Hansen, Karen; Harrold, Paul; Heller, Gregory; Herrera, Cesar; Hirayama, Kazuyuki; Hirooka, Yuuri; Ho, Hsiao-Man; Hoffmann, Kerstin; Hofstetter, Valérie; Högnabba, Filip; Hollingsworth, Peter M.; Hong, Seung-Beom; Hosaka, Kentaro; Houbraken, Jos; Hughes, Karen; Huhtinen, Seppo; Hyde, Kevin D.; James, Timothy; Johnson, Eric M.; Johnson, Joan E.; Johnston, Peter R.; Jones, E.B. Gareth; Kelly, Laura J.; Kirk, Paul M.; Knapp, Dániel G.; Kõljalg, Urmas; Kovács, Gábor M.; Kurtzman, Cletus P.; Landvik, Sara; Leavitt, Steven D.; Liggenstoffer, Audra S.; Liimatainen, Kare; Lombard, Lorenzo; Luangsa-ard, J. Jennifer; Lumbsch, H. Thorsten; Maganti, Harinad; Maharachchikumbura, Sajeewa S. N.; Martin, María P.; May, Tom W.; McTaggart, Alistair R.; Methven, Andrew S.; Meyer, Wieland; Moncalvo, Jean-Marc; Mongkolsamrit, Suchada; Nagy, László G.; Nilsson, R. Henrik; Niskanen, Tuula; Nyilasi, Ildikó; Okada, Gen; Okane, Izumi; Olariaga, Ibai; Otte, Jürgen; Papp, Tamás; Park, Duckchul; Petkovits, Tamás; Pino-Bodas, Raquel; Quaedvlieg, William; Raja, Huzefa A.; Redecker, Dirk; Rintoul, Tara L.; Ruibal, Constantino; Sarmiento-Ramírez, Jullie M.; Schmitt, Imke; Schüßler, Arthur; Shearer, Carol; Sotome, Kozue; Stefani, Franck O.P.; Stenroos, Soili; Stielow, Benjamin; Stockinger, Herbert; Suetrong, Satinee; Suh, Sung-Oui; Sung, Gi-Ho; Suzuki, Motofumi; Tanaka, Kazuaki; Tedersoo, Leho; Telleria, M. Teresa; Tretter, Eric; Untereiner, Wendy A.; Urbina, Hector; Vágvölgyi, Csaba; Vialle, Agathe; Vu, Thuy Duong; Walther, Grit; Wang, Qi-Ming; Wang, Yan; Weir, Bevan S.; Weiß, Michael; White, Merlin M.; Xu, Jianping; Yahr, Rebecca; Yang, Zhu L.; Yurkov, Andrey; Zamora, Juan-Carlos; Zhang, Ning; Zhuang, Wen-Ying; Schindel, David

    2012-01-01

    Six DNA regions were evaluated as potential DNA barcodes for Fungi, the second largest kingdom of eukaryotic life, by a multinational, multilaboratory consortium. The region of the mitochondrial cytochrome c oxidase subunit 1 used as the animal barcode was excluded as a potential marker, because it is difficult to amplify in fungi, often includes large introns, and can be insufficiently variable. Three subunits from the nuclear ribosomal RNA cistron were compared together with regions of three representative protein-coding genes (largest subunit of RNA polymerase II, second largest subunit of RNA polymerase II, and minichromosome maintenance protein). Although the protein-coding gene regions often had a higher percent of correct identification compared with ribosomal markers, low PCR amplification and sequencing success eliminated them as candidates for a universal fungal barcode. Among the regions of the ribosomal cistron, the internal transcribed spacer (ITS) region has the highest probability of successful identification for the broadest range of fungi, with the most clearly defined barcode gap between inter- and intraspecific variation. The nuclear ribosomal large subunit, a popular phylogenetic marker in certain groups, had superior species resolution in some taxonomic groups, such as the early diverging lineages and the ascomycete yeasts, but was otherwise slightly inferior to the ITS. The nuclear ribosomal small subunit has poor species-level resolution in fungi. ITS will be formally proposed for adoption as the primary fungal barcode marker to the Consortium for the Barcode of Life, with the possibility that supplementary barcodes may be developed for particular narrowly circumscribed taxonomic groups. PMID:22454494

  11. Complete nuclear ribosomal DNA sequence amplification and molecular analyses of Bangia (Bangiales, Rhodophyta) from China

    Science.gov (United States)

    Xu, Jiajie; Jiang, Bo; Chai, Sanming; He, Yuan; Zhu, Jianyi; Shen, Zonggen; Shen, Songdong

    2016-09-01

    Filamentous Bangia, which are distributed extensively throughout the world, have simple and similar morphological characteristics. Scientists can classify these organisms using molecular markers in combination with morphology. We successfully sequenced the complete nuclear ribosomal DNA, approximately 13 kb in length, from a marine Bangia population. We further analyzed the small subunit ribosomal DNA gene (nrSSU) and the internal transcribed spacer (ITS) sequence regions along with nine other marine, and two freshwater Bangia samples from China. Pairwise distances of the nrSSU and 5.8S ribosomal DNA gene sequences show the marine samples grouping together with low divergences (00.003; 0-0.006, respectively) from each other, but high divergences (0.123-0.126; 0.198, respectively) from freshwater samples. An exception is the marine sample collected from Weihai, which shows high divergence from both other marine samples (0.063-0.065; 0.129, respectively) and the freshwater samples (0.097; 0.120, respectively). A maximum likelihood phylogenetic tree based on a combined SSU-ITS dataset with maximum likelihood method shows the samples divided into three clades, with the two marine sample clades containing Bangia spp. from North America, Europe, Asia, and Australia; and one freshwater clade, containing Bangia atropurpurea from North America and China.

  12. Isolation and molecular identification of Vibrio spp. by sequencing of 16S rDNA from seafood, meat and meat products in Libya.

    Science.gov (United States)

    Azwai, S M; Alfallani, E A; Abolghait, S K; Garbaj, A M; Naas, H T; Moawad, A A; Gammoudi, F T; Rayes, H M; Barbieri, I; Eldaghayes, I M

    2016-01-01

    The genus Vibrio includes several food-borne pathogens that cause a spectrum of clinical conditions including septicemia, cholera and milder forms of gastroenteritis. Several Vibrio spp. are commonly associated with food-borne transmission including Vibrio cholerae, Vibrio parahemolyticus, and Vibrio vulnificus. Microbiological analysis for enumeration and isolation of Vibrio spp. were carried out for a total of 93 samples of seafood, meat and meat products from different geographic localities in Libya (Tripoli, Regdalin, Janzour and Tobruk). Vibrio spp. were detected by conventional cultural and molecular method using PCR and sequencing of 16S rDNA. Out of the 93 cultured samples only 48 (51.6%) yielded colonies on Thiosulfate Citrate Bile Salt agar (TCBS) with culture characteristics of Vibrio spp. More than half (n=27) of processed seafood samples (n=46) yielded colonies on TCBS, while only 44.6 % of samples of meat and meat products showed colonies on TCBS. Among cultured seafood samples, the highest bacterial count was recorded in clam with a count of 3.8 ×10(4) CFU\\g. Chicken burger samples showed the highest bacterial count with 6.5 ×10(4) CFU\\g. Molecular analysis of the isolates obtained in this study, showed that 11 samples out of 48 (22.9%) were Vibrio spp. Vibrio parahemolyticus was isolated from camel meat for the first time. This study is an initial step to provide a baseline for future molecular research targeting Vibrio spp. foodborne illnesses. This data will be used to provide information on the magnitude of such pathogens in Libyan seafood, meat and meat products.

  13. Isolation and molecular identification of Vibrio spp. by sequencing of 16S rDNA from seafood, meat and meat products in Libya

    Directory of Open Access Journals (Sweden)

    S.M. Azwai

    2016-03-01

    Full Text Available The genus Vibrio includes several food-borne pathogens that cause a spectrum of clinical conditions including septicemia, cholera and milder forms of gastroenteritis. Several Vibrio spp. are commonly associated with food-borne transmission including Vibrio cholerae, Vibrio parahemolyticus, and Vibrio vulnificus. Microbiological analysis for enumeration and isolation of Vibrio spp. were carried out for a total of 93 samples of seafood, meat and meat products from different geographic localities in Libya (Tripoli, Regdalin, Janzour and Tobruk. Vibrio spp. were detected by conventional cultural and molecular method using PCR and sequencing of 16S rDNA. Out of the 93 cultured samples only 48 (51.6% yielded colonies on Thiosulfate Citrate Bile Salt agar (TCBS with culture characteristics of Vibrio spp. More than half (n=27 of processed seafood samples (n=46 yielded colonies on TCBS, while only 44.6% of samples of meat and meat products showed colonies on TCBS. Among cultured seafood samples, the highest bacterial count was recorded in clam with a count of 3.8 х104 CFU\\g. Chicken burger samples showed the highest bacterial count with 6.5 х104 CFU\\g. Molecular analysis of the isolates obtained in this study, showed that 11 samples out of 48 (22.9% were Vibrio spp. Vibrio parahemolyticus was isolated from camel meat for the first time. This study is an initial step to provide a baseline for future molecular research targeting Vibrio spp. foodborne illnesses. This data will be used to provide information on the magnitude of such pathogens in Libyan seafood, meat and meat products.

  14. Isolation and molecular identification of Vibrio spp. by sequencing of 16S rDNA from seafood, meat and meat products in Libya.

    Science.gov (United States)

    Azwai, S M; Alfallani, E A; Abolghait, S K; Garbaj, A M; Naas, H T; Moawad, A A; Gammoudi, F T; Rayes, H M; Barbieri, I; Eldaghayes, I M

    2016-01-01

    The genus Vibrio includes several food-borne pathogens that cause a spectrum of clinical conditions including septicemia, cholera and milder forms of gastroenteritis. Several Vibrio spp. are commonly associated with food-borne transmission including Vibrio cholerae, Vibrio parahemolyticus, and Vibrio vulnificus. Microbiological analysis for enumeration and isolation of Vibrio spp. were carried out for a total of 93 samples of seafood, meat and meat products from different geographic localities in Libya (Tripoli, Regdalin, Janzour and Tobruk). Vibrio spp. were detected by conventional cultural and molecular method using PCR and sequencing of 16S rDNA. Out of the 93 cultured samples only 48 (51.6%) yielded colonies on Thiosulfate Citrate Bile Salt agar (TCBS) with culture characteristics of Vibrio spp. More than half (n=27) of processed seafood samples (n=46) yielded colonies on TCBS, while only 44.6 % of samples of meat and meat products showed colonies on TCBS. Among cultured seafood samples, the highest bacterial count was recorded in clam with a count of 3.8 ×10(4) CFU\\g. Chicken burger samples showed the highest bacterial count with 6.5 ×10(4) CFU\\g. Molecular analysis of the isolates obtained in this study, showed that 11 samples out of 48 (22.9%) were Vibrio spp. Vibrio parahemolyticus was isolated from camel meat for the first time. This study is an initial step to provide a baseline for future molecular research targeting Vibrio spp. foodborne illnesses. This data will be used to provide information on the magnitude of such pathogens in Libyan seafood, meat and meat products. PMID:27004169

  15. High-throughput sequencing of 16S rDNA amplicons characterizes bacterial composition in bronchoalveolar lavage fluid in patients with ventilator-associated pneumonia

    Directory of Open Access Journals (Sweden)

    Yang XJ

    2015-08-01

    Full Text Available Xiao-Jun Yang,1,* Yan-Bo Wang,2,3,* Zhi-Wei Zhou,4,* Guo-Wei Wang,2 Xiao-Hong Wang,1 Qing-Fu Liu,1 Shu-Feng Zhou,4 Zhen-Hai Wang2,3 1Department of Intensive Care Unit, 2Neurology Center, General Hospital of Ningxia Medical University, Yinchuan, Ningxia, People’s Republic of China; 3Key Laboratory of Brain Diseases of Ningxia, Yinchuan, Ningxia, People’s Republic of China; 4Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA *These authors contributed equally to this work Abstract: Ventilator-associated pneumonia (VAP is a life-threatening disease that is associated with high rates of morbidity and likely mortality, placing a heavy burden on an individual and society. Currently available diagnostic and therapeutic approaches for VAP treatment are limited, and the prognosis of VAP is poor. The present study aimed to reveal and discriminate the identification of the full spectrum of the pathogens in patients with VAP using high-throughput sequencing approach and analyze the species richness and complexity via alpha and beta diversity analysis. The bronchoalveolar lavage fluid samples were collected from 27 patients with VAP in intensive care unit. The polymerase chain reaction products of the hypervariable regions of 16S rDNA gene in these 27 samples of VAP were sequenced using the 454 GS FLX system. A total of 103,856 pyrosequencing reads and 638 operational taxonomic units were obtained from these 27 samples. There were four dominant phyla, including Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. There were 90 different genera, of which 12 genera occurred in over ten different samples. The top five dominant genera were Streptococcus, Acinetobacter, Limnohabitans, Neisseria, and Corynebacterium, and the most widely distributed genera were Streptococcus, Limnohabitans, and Acinetobacter in these 27 samples. Of note, the mixed profile of causative pathogens was observed. Taken

  16. A PCR Assay To Discriminate Human and Ruminant Feces on the Basis of Host Differences in Bacteroides-Prevotella Genes Encoding 16S rRNA

    OpenAIRE

    Bernhard, Anne E.; Field, Katharine G.

    2000-01-01

    Our purpose was to develop a rapid, inexpensive method of diagnosing the source of fecal pollution in water. In previous research, we identified Bacteroides-Prevotella ribosomal DNA (rDNA) PCR markers based on analysis. These markers length heterogeneity PCR and terminal restriction fragment length polymorphism distinguish cow from human feces. Here, we recovered 16S rDNA clones from natural waters that were close phylogenetic relatives of the markers. From the sequence data, we designed spec...

  17. Broad-range PCR, cloning and sequencing of the full 16S rRNA gene for detection of bacterial DNA in synovial fluid samples of Tunisian patients with reactive and undifferentiated arthritis

    OpenAIRE

    Siala, Mariam; Gdoura, Radhouane; Fourati, Hela; Rihl, Markus; Jaulhac, Benoit; Younes, Mohamed; Sibilia, Jean; Baklouti, Sofien; Bargaoui, Naceur; Sellami, Slaheddine; Sghir, Abdelghani; Hammami, Adnane

    2009-01-01

    Introduction Broad-range rDNA PCR provides an alternative, cultivation-independent approach for identifying bacterial DNA in reactive and other form of arthritis. The aim of this study was to use broad-range rDNA PCR targeting the 16S rRNA gene in patients with reactive and other forms of arthritis and to screen for the presence of DNA from any given bacterial species in synovial fluid (SF) samples. Methods We examined the SF samples from a total of 27 patients consisting of patients with rea...

  18. Integrated next-generation sequencing of 16S rDNA and metaproteomics differentiate the healthy urine microbiome from asymptomatic bacteriuria in neuropathic bladder associated with spinal cord injury

    Directory of Open Access Journals (Sweden)

    Fouts Derrick E

    2012-08-01

    Full Text Available Abstract Background Clinical dogma is that healthy urine is sterile and the presence of bacteria with an inflammatory response is indicative of urinary tract infection (UTI. Asymptomatic bacteriuria (ABU represents the state in which bacteria are present but the inflammatory response is negligible. Differentiating ABU from UTI is diagnostically challenging, but critical because overtreatment of ABU can perpetuate antimicrobial resistance while undertreatment of UTI can result in increased morbidity and mortality. In this study, we describe key characteristics of the healthy and ABU urine microbiomes utilizing 16S rRNA gene (16S rDNA sequencing and metaproteomics, with the future goal of utilizing this information to personalize the treatment of UTI based on key individual characteristics. Methods A cross-sectional study of 26 healthy controls and 27 healthy subjects at risk for ABU due to spinal cord injury-related neuropathic bladder (NB was conducted. Of the 27 subjects with NB, 8 voided normally, 8 utilized intermittent catheterization, and 11 utilized indwelling Foley urethral catheterization for bladder drainage. Urine was obtained by clean catch in voiders, or directly from the catheter in subjects utilizing catheters. Urinalysis, urine culture and 16S rDNA sequencing were performed on all samples, with metaproteomic analysis performed on a subsample. Results A total of 589454 quality-filtered 16S rDNA sequence reads were processed through a NextGen 16S rDNA analysis pipeline. Urine microbiomes differ by normal bladder function vs. NB, gender, type of bladder catheter utilized, and duration of NB. The top ten bacterial taxa showing the most relative abundance and change among samples were Lactobacillales, Enterobacteriales, Actinomycetales, Bacillales, Clostridiales, Bacteroidales, Burkholderiales, Pseudomonadales, Bifidobacteriales and Coriobacteriales. Metaproteomics confirmed the 16S rDNA results, and functional human protein

  19. Quantification of Hyphomicrobium Populations in Activated Sludge from an Industrial Wastewater Treatment System as Determined by 16S rRNA Analysis

    OpenAIRE

    Layton, A C; Karanth, P. N.; Lajoie, C. A.; Meyers, A J; Gregory, I. R.; Stapleton, R. D.; Taylor, D E; Sayler, G. S.

    2000-01-01

    The bacterial community structure of the activated sludge from a 25 million-gal-per-day industrial wastewater treatment plant was investigated using rRNA analysis. 16S ribosomal DNA (rDNA) libraries were created from three sludge samples taken on different dates. Partial rRNA gene sequences were obtained for 46 rDNA clones, and nearly complete 16S rRNA sequences were obtained for 18 clones. Seventeen of these clones were members of the beta subdivision, and their sequences showed high homolog...

  20. Detection of 16S rDNA and PIA genes of Neisseria isolated from the patients with male genitourinary tract infections%男性泌尿生殖道感染患者分离奈瑟菌的16S rDNA和PIA基因检测

    Institute of Scientific and Technical Information of China (English)

    姜敏敏; 王涛; 王和

    2012-01-01

    目的 检测男性泌尿生殖道分离奈瑟菌的16S rDNA和PIA基因,探讨奈瑟菌属菌种的基因鉴定及其致病机理.方法 用PCR扩增和核苷酸序列分析方法分别检测11例男性泌尿生殖道感染患者泌尿生殖道分离的14株奈瑟菌属菌种的16S rDNA和PIA基因及其序列.结果 14株奈瑟菌属菌种经16S rDNA检测鉴定分别为淋病奈瑟菌2株,黏液奈瑟菌3株,灰色奈瑟菌5株,微黄奈瑟菌2株,干燥奈瑟菌1株,嗜乳糖奈瑟菌及多糖奈瑟菌各1株;与常规细菌学方法鉴定的符合率为85.7%.非淋球菌奈瑟菌未检出淋病奈瑟菌毒力相关的PIA核苷酸序列.结论 常规细菌学方法与染色体16S rDNA检测及其序列分析方法的联合使用,可提高奈瑟菌属菌种感染的实验室诊断准确率;PIA基因对于奈瑟菌属的男性生殖道致病性无关.%Objective To detect the 16S rDNA and PIA genes of Neisseria isolated from the patients with male genitourinary tract infections and investigate the gene identification and pathogenesis of Neisseria species. Methods The 16S rRNA and PIA genes and their sequences of 14 Neisseria species isolated from reproductive tract of 11 patients with male genitourinary tract infections were identified by PCR amplification and nucleotide sequencing. Results Fourteen Neisseria strains contained 2 strains of Neisseria gonorrhoeae, 3 strains of Neisseria mucosa, 5 strains of Neisseria cinerea, 2 strain of Neisseria subflava, 1 strain of Neisseria sicca,1 strain of Neisseria lactamica and 1 strain of Neisseria polysaccharea. The accordance rate of the results reported by 16S rDNA and routine bacteriological method was 85. 7%. The nucleotide sequence of virulence-associated gene PIA of Neisseria gonorrhoeae was not found in non-gonococcal strains of Neisseria. Conclusion The accuracy rate of laboratory diagnosis for the infection caused by Neisseria can be improved by combined use of routine bacteriological method and 16S rDNA

  1. Specific primers for PCR amplification of the ITS1 (ribosomal DNA) of Trypanosoma lewisi.

    Science.gov (United States)

    Desquesnes, Marc; Marc, Desquesnes; Kamyingkird, Ketsarin; Ketsarin, Kamyingkird; Yangtara, Sarawut; Sarawut, Yangtara; Milocco, Cristina; Cristina, Milocco; Ravel, Sophie; Sophie, Ravel; Wang, Ming-Hui; Ming-Hui, Wang; Lun, Zhao-Rong; Zhao-Rong, Lun; Morand, Serge; Serge, Morand; Jittapalapong, Sathaporn; Sathaporn, Jittapalapong

    2011-08-01

    Trypanosoma lewisi is a mild or non-pathogenic parasite of the sub-genus Herpetosoma transmitted by fleas to rats. In a previous study we described pan-trypanosome specific primers TRYP1 which amplify the ITS1 of ribosomal DNA by hybridizing in highly conserved regions of 18S and 5.8S genes. These primers proved to be useful for detecting T. lewisi DNA in laboratory rats, but a recent large scale survey in wild rodents demonstrated a lack of specificity. In the present study, we designed and evaluated mono-specific primers LEW1S and LEW1R, for the detection and identification of T. lewisi by a single-step PCR. These primers were designed inside the highly variable region of the ITS1 sequence of T. lewisi ribosomal DNA. The product size of 220 bp is specific to T. lewisi. The sensitivity limit was estimated between 0.055 and 0.55 pg of DNA per reaction, equivalent to 1-10 organisms per reaction. All the PCR products obtained from 6 different T. lewisi isolates were more than 98% similar with each other and similar to the sequences of T. lewisi already published in Genbank. All DNA of 7 T. lewisi stocks from China gave the specific 220 bp product. We showed that LEW1S and LEW1R primers enabled sensitive detection and identification of T. lewisi infection in laboratory and wild rats. This assay is recommended for monitoring T. lewisi infections in rat colonies or for studying infections in the wild fauna. An absence of cross reaction with human DNA means that these primers can be used to investigate atypical trypanosome infections in humans. Given the risk of T. lewisi infection in human, we believe that these primers will be beneficial for public health diagnosis and rodents investigation programmes. PMID:21570489

  2. 18S Ribosomal RNA Evaluation as Preanalytical Quality Control for Animal DNA

    Directory of Open Access Journals (Sweden)

    Cory Ann Leonard

    2016-01-01

    Full Text Available The 18S ribosomal RNA (rRNA gene is present in all eukaryotic cells. In this study, we evaluated the use of this gene to verify the presence of PCR-amplifiable host (animal DNA as an indicator of sufficient sample quality for quantitative real-time PCR (qPCR analysis. We compared (i samples from various animal species, tissues, and sample types, including swabs; (ii multiple DNA extraction methods; and (iii both fresh and formalin-fixed paraffin-embedded (FFPE samples. Results showed that 18S ribosomal RNA gene amplification was possible from all tissue samples evaluated, including avian, reptile, and FFPE samples and most swab samples. A single swine rectal swab, which showed sufficient DNA quantity and the demonstrated lack of PCR inhibitors, nonetheless was negative by 18S qPCR. Such a sample specifically illustrates the improvement of determination of sample integrity afforded by inclusion of 18S rRNA gene qPCR analysis in addition to spectrophotometric analysis and the use of internal controls for PCR inhibition. Other possible applications for the described 18S rRNA qPCR are preselection of optimal tissue specimens for studies or preliminary screening of archived samples prior to acceptance for biobanking projects.

  3. Chromosomal localization of ribosomal DNA sequences in an apple rootstock using a digoxygenin detection system

    Institute of Scientific and Technical Information of China (English)

    ZHUJIMEI; SEGARDINER

    1995-01-01

    A 6kb rDNA probe comprising the 18S coding plus spacer sequences has been hybridized to the metaphase chromosomes of apple rootstock cultivar MM106 demonstrating the localization of ribosomal gene arrays in the vicinity of the telomeric regions of the short arms of chromosomes 6 and 14.The in situ results using digoxygenin labelling coupled to an alkaline phosphatase immunoassay were confirmed by silver staining for NORs and nucleoli.This study demonstrates the feasibility of molecular cytogenetic analysis of very small chromosomes(1.0-2.7μm) of apple.

  4. 基于16S rDNA和COⅠ基因序列探讨四种溞类的系统关系和分类地位%PHYLOGENETIC RELATIONSHIP AND TAXONOMIC STATUS OF FOUR DAPHNIA SPECIES BASED ON 16S rDNA AND COⅠSEQUENCE

    Institute of Scientific and Technical Information of China (English)

    徐敏; 张海军; 邓道贵; 王文平; 张晓莉; 查岭生

    2014-01-01

    为了检验已记录的4个溞属种类(隆线溞Daphnia carinata 溞、透明 D. hyalina 溞、蚤状 D. pulex和大型溞D. magna)的系统分类,用试剂盒法分别提取4种溞类的基因组DNA。利用特异性引物,通过PCR扩增了4种溞属种类的16S rDNA和COⅠ基因部分序列,并与来自GenBank中每个种类相似度较高的同种序列进行分析。结果表明,基于16S rDNA和COⅠ基因,4个溞属种类的平均种间相似度分别为85.56%和80.67%,碱基中A+T含量均明显高于G+C含量。基于COⅠ基因,溞巢湖隆线与来自GenBank 溞上的拟同形(Daphnia similoides AB549199)相似度为99%,分歧度为0.4%-0.9%。就16S rDNA和COⅠ基因而言,溞巢湖透明更溞接近于盔形(Daphnia galeata)。基于16S rDNA和COⅠ基因构建的NJ树和贝叶斯树,两者的主要分枝基本一致。结果暗示,溞溞巢湖隆线与拟同形为一个种,溞溞透明应属于盔形。由于缺乏核基因的研究,有关巢湖溞属的分类地位还需进行更深入的探讨。%To examine the systematic classification of four previously-recorded Daphnia species, D. carinata, D. hya-lina, D. pulex, and D. magna, genomic DNAs of these species were extracted and PCR was used to amplify fragments of 16S rDNA and COⅠ gene by employing specific primers. The sequences of amplified fragments were compared with Daphnia species from the GeneBank. Based on 16S rDNA and COⅠ gene, the average interspecific similarity rate of four Daphnia species was 85.25% and 80.67% respectively, and the content of A+T was obviously higher than that of G+C. The similarity of D. carinata from Lake chaohu and D. similoides (AB549199) from the GeneBank was 99%ac-cording to COⅠ gene and the divergence rate was 0.4%-0.9%. D. hyalina from Lake Chaohu was more close to D. galeata from the GeneBank based on 16S rDNA or COⅠgene. Main branches of both NJ tree and bayes tree were similar. The results indicated that D. carinata and D. similoides were the same

  5. Identidade molecular dos fitoplasmas associados aos enfezamentos do tomateiro e da berinjela com base na análise do gene 16S rDNA Molecular identity of the phytoplasma associated to stunting of tomato and eggplant on the basis of analyses of the 16S rDNA

    Directory of Open Access Journals (Sweden)

    Ana Paula de Oliveira Amaral Mello

    2007-09-01

    Full Text Available Doenças de hortaliças de ocorrência no território brasileiro e em outras áreas do mundo têm sido associadas a diversos fitoplasmas. Na região de Piracicaba-SP e Bragança Paulista-SP, em plantas de tomate e berinjela foram observados sintomas típicos de enfezamento caracterizados por porte reduzido, clorose foliar, superbrotamento de ramos, desenvolvimento anormal do cálice, encurtamento de entre-nós, redução no tamanho de folhas, flores e frutos. Através de duplo PCR, utilizando os iniciadores R16 mF1/mR2 e R16 F2n/R2, fragmentos de DNA de 1,2 kb foram amplificados de amostras sintomáticas, demonstrando a presença de fitoplasma nos tecidos das plantas. O uso de iniciadores específicos demonstrou que estes fitoplasmas eram afiliados ao grupo 16SrIII. Análises de RFLP, usando as enzimas de restrição AluI, HpaII, KpnI, MboI, MseI e RsaI confirmaram que os fitoplasmas detectados eram representantes do grupo 16SrIII. Os fragmentos de DNA amplificados foram clonados em Escherichia coli, sequenciados e comparados, por homologia de seqüência, entre si e com outros fitoplasmas do grupo 16SrIII. Um índice de similaridade de seqüência acima de 95% foi encontrado quando seqüências dos fitoplasmas detectados em tomate e berinjela foram comparadas com aquelas de outros representantes do grupo 16SrIII. Um índice de 98-99% foi obtido quando seqüências dos fitoplasmas encontrados em tomate e berinjela foram comparadas entre si. Estes resultados evidenciaram que o enfezamento do tomateiro e da berinjela podem estar associados a um mesmo fitoplasma, com base na análise de seqüências do gene do 16S rDNA.Vegetable diseases occurring in the Brazilian territory and around the world have been associated with various phytoplasmas. In the region of Piracicaba-SP and Bragança-SP, in eggplant and tomato plants typical symptoms of stunting characterized by reduced canopy, leaf yellowing, proliferation of shoots, calix malformation

  6. 稻纵卷叶螟感染Wolbachia的ftsZ基因和16S rDNA基因的序列分析%Sequence analysis of ftsZ and 16S rDNA genes of Wolbachia in Cnaphalocrocis medinalis (Guenée) ( Lepidoptera: Pyralidae)

    Institute of Scientific and Technical Information of China (English)

    柴换娜; 杜予州; 吴海燕

    2011-01-01

    Wolbachia is a group of intracellular inherited endosymbiontic bacteria infecting a wide range of arthropods and other animals. The infection status of Wolbachia in the migratory pest Cnaphalocrocis medinalis (Guenée) was studied to provide the basis for revealing the reproductive manipulation mechanism and transmission mechanism of Wolbachia in this pest. In this study, specific primers derived fromftsZ and 16S rDNA genes were used to amplify DNA of Wolbachia from 20 populations of C. medinalis in China by polymerase chain reaction (PCR). The results indicated that the C. medinalis populations in China were widely infected by Wolbachia, the highest infection rate was 90% in Wenzhou of Zhejiang and Yangzhou of Jiangsu, and the lowest rate was 40% in Ya' an of Sichuan, Changsha of Hunan and Ninghe of Tianjin.The ftsZ sequences and 16S rDNA sequences were exactly the same in all positive samples from different regions. Wolbachia ftsZ sequences and 16S rDNA sequences in C. medinalis showed 99% - 100% and 98% -99% similarity with others belonging to Group B, respectively, suggesting that Wolbachia in C.medinalis belong to Group B. The results show that the infection type of Wolbachia in the C. medinalis is relatively ingle. This is the first report that Wolbachia is distributed in the populations of C. maedinalis in China.%Wolbachia是一类胞质遗传的内共生菌,广泛分布于节肢动物和其他动物中,与宿主的生殖调控密切相关.通过研究迁飞性害虫稻纵卷叶螟Cnaphalocrocis medinalis(Guen e)的Wolbachia感染情况,为探讨Wolbachia在迁飞性昆虫中的生殖调控和传递方式等提供基础资料.本研究应用Wolbachia的ftsZ基因和16S rDNA基因的特异性引物,通过PCR扩增的方法对我国20个地区的稻纵卷叶螟样本进行了检测.结果表明:中国不同地区的稻纵卷叶螟感染Wolbachia的现象较为普遍,其中浙江温州和江苏扬州样本的感染率最高(90%);四川雅安、湖

  7. Diversity and recombination of dispersed ribosomal DNA and protein coding genes in microsporidia.

    Directory of Open Access Journals (Sweden)

    Joseph Edward Ironside

    Full Text Available Microsporidian strains are usually classified on the basis of their ribosomal DNA (rDNA sequences. Although rDNA occurs as multiple copies, in most non-microsporidian species copies within a genome occur as tandem arrays and are homogenised by concerted evolution. In contrast, microsporidian rDNA units are dispersed throughout the genome in some species, and on this basis are predicted to undergo reduced concerted evolution. Furthermore many microsporidian species appear to be asexual and should therefore exhibit reduced genetic diversity due to a lack of recombination. Here, DNA sequences are compared between microsporidia with different life cycles in order to determine the effects of concerted evolution and sexual reproduction upon the diversity of rDNA and protein coding genes. Comparisons of cloned rDNA sequences between microsporidia of the genus Nosema with different life cycles provide evidence of intragenomic variability coupled with strong purifying selection. This suggests a birth and death process of evolution. However, some concerted evolution is suggested by clustering of rDNA sequences within species. Variability of protein-coding sequences indicates that considerable intergenomic variation also occurs between microsporidian cells within a single host. Patterns of variation in microsporidian DNA sequences indicate that additional diversity is generated by intragenomic and/or intergenomic recombination between sequence variants. The discovery of intragenomic variability coupled with strong purifying selection in microsporidian rRNA sequences supports the hypothesis that concerted evolution is reduced when copies of a gene are dispersed rather than repeated tandemly. The presence of intragenomic variability also renders the use of rDNA sequences for barcoding microsporidia questionable. Evidence of recombination in the single-copy genes of putatively asexual microsporidia suggests that these species may undergo cryptic sexual

  8. Genetic Diversity of Methylotrophic Bacteria from Human Mouth Based on Amplified Ribosomal DNA Restriction Analysis (ARDRA

    Directory of Open Access Journals (Sweden)

    CINDY OKTAVIA SUSANTO

    2011-06-01

    Full Text Available Methylotrophs inhabit the human mouth. In this study, methylotrophic bacteria were isolated from the human mouth microflora of 63 subjects, especially from the tongue, gingival, and subgingival area using minimal agar supplemented with 1% methanol. The obtained isolates were subjected to biochemical assays, continued with antibiotics susceptibility testing using ampicillin (10 g, tetracycline (20 g, kanamycin (30 g, trimethoprim (5 g, and streptomycin (10 g. Genetic diversity was analyzed using ARDRA method. Isolates varying in morphology characteristics were amplified for 16S rRNA gene and continued with DNA sequencing. As many as 21 methylotrophic bacterial isolates were purified and divided into seven groups with different phenotypic profiles. A majority of the isolates were resistant to trimethoprim but sensitive to kanamycin, streptomycin, and tetracycline. Resistance to ampicillin was variable in each isolate. ARDRA showed nine different digestion profiles. DNA sequencing analysis of the 16S rRNA gene showed that six isolates with different phenotypic and digestion profiles were closely related to Methylobacterium radiotoleran (94%, Microbacterium esteraromaticum (99%, Pseudomonas sp. (100%, and three of them were exhibited 99, 99, and 98% sequence similarity with Gordonia sp., respectively. The results of this study revealed diversity among methylotrophic bacteria particularly in human mouth.

  9. Nucleolar organization, ribosomal DNA array stability, and acrocentric chromosome integrity are linked to telomere function.

    Directory of Open Access Journals (Sweden)

    Kaitlin M Stimpson

    Full Text Available The short arms of the ten acrocentric human chromosomes share several repetitive DNAs, including ribosomal RNA genes (rDNA. The rDNA arrays correspond to nucleolar organizing regions that coalesce each cell cycle to form the nucleolus. Telomere disruption by expressing a mutant version of telomere binding protein TRF2 (dnTRF2 causes non-random acrocentric fusions, as well as large-scale nucleolar defects. The mechanisms responsible for acrocentric chromosome sensitivity to dysfunctional telomeres are unclear. In this study, we show that TRF2 normally associates with the nucleolus and rDNA. However, when telomeres are crippled by dnTRF2 or RNAi knockdown of TRF2, gross nucleolar and chromosomal changes occur. We used the controllable dnTRF2 system to precisely dissect the timing and progression of nucleolar and chromosomal instability induced by telomere dysfunction, demonstrating that nucleolar changes precede the DNA damage and morphological changes that occur at acrocentric short arms. The rDNA repeat arrays on the short arms decondense, and are coated by RNA polymerase I transcription binding factor UBF, physically linking acrocentrics to one another as they become fusogenic. These results highlight the importance of telomere function in nucleolar stability and structural integrity of acrocentric chromosomes, particularly the rDNA arrays. Telomeric stress is widely accepted to cause DNA damage at chromosome ends, but our findings suggest that it also disrupts chromosome structure beyond the telomere region, specifically within the rDNA arrays located on acrocentric chromosomes. These results have relevance for Robertsonian translocation formation in humans and mechanisms by which acrocentric-acrocentric fusions are promoted by DNA damage and repair.

  10. Wnt5a Signals through DVL1 to Repress Ribosomal DNA Transcription by RNA Polymerase I

    Science.gov (United States)

    Dass, Randall A.; Sarshad, Aishe A.; Feenstra, Jennifer M.; Kaur, Amanpreet; Pietras, Kristian; Serra, Rosa; Blanchard, Scott C.; Percipalle, Piergiorgio; Brown, Anthony M. C.; Vincent, C. Theresa

    2016-01-01

    Ribosome biogenesis is essential for cell growth and proliferation and is commonly elevated in cancer. Accordingly, numerous oncogene and tumor suppressor signaling pathways target rRNA synthesis. In breast cancer, non-canonical Wnt signaling by Wnt5a has been reported to antagonize tumor growth. Here, we show that Wnt5a rapidly represses rDNA gene transcription in breast cancer cells and generates a chromatin state with reduced transcription of rDNA by RNA polymerase I (Pol I). These effects were specifically dependent on Dishevelled1 (DVL1), which accumulates in nucleolar organizer regions (NORs) and binds to rDNA regions of the chromosome. Upon DVL1 binding, the Pol I transcription activator and deacetylase Sirtuin 7 (SIRT7) releases from rDNA loci, concomitant with disassembly of Pol I transcription machinery at the rDNA promoter. These findings reveal that Wnt5a signals through DVL1 to suppress rRNA transcription. This provides a novel mechanism for how Wnt5a exerts tumor suppressive effects and why disruption of Wnt5a signaling enhances mammary tumor growth in vivo. PMID:27500936

  11. Application of the identification of sarcosaphagous flies by analyses the sequence of 16SrDNA%利用16S rDNA序列鉴定常见嗜尸性蝇类种属

    Institute of Scientific and Technical Information of China (English)

    陈凤磊; 蔡继峰; 郭亚东; 常云峰; 杨立

    2011-01-01

    目的 通过分析16S rDNA 551bp基因序列,鉴定常见嗜尸性蝇类种属.方法 随机采集17个地区放置于室外草地的家兔尸体上7个种24只嗜尸性苍蝇样本,经形态学鉴定种类后,提取胸肌DNA,对16S rDNA 551bp基因片段进行PCR扩增,产物纯化、测序后上传GenBank;利用MEGA 4.0软件构建序列间的系统发育树,分析建立种内及种间进化分歧表.结果 24只样本16S rDNA序列分析显示7种蝇类可以较好聚类;其中棕尾别麻蝇种内进化分歧整体均数为2.8%,家蝇为1.5%,丽蝇科的5个种均在0.7%以内.上述7个蝇种的种间进化分歧均数在1.6% ~7.1%之间.其中,棕尾别麻蝇、家蝇与其它蝇类的种间分歧均数在4.0% ~7.1%之间.结论 本文分析结果显示,蝇种间同源性相差明显,采用mtDNA 16S rDNA中551bp基因序列分析,可进行蝇种鉴定.%Objective Identifing species of Sarcosaphagous flies by analyzing the amplified 551bp of 16S rDNA. Methods Twenty-four Samples of sarcossphagous flies belong to seven species on the corpses of rabbits were collected from seventeen districts. All samples were identified by entomologists using traditional morphological characteristics and then the Mitochondrial DNA of flies was extracted using the phenol chloroform extraction. Polymerase chain reactions were conducted on a Perkin-Elmer 9600 thermal cycler. PCR products were purified using Nucleic Acid Purification Kit. The PCR products were sequenced and the obtained sequences have been deposited in CenBank by Sequin. A neighbour-joining tree using the Tamura and Nei model of nucleotide substitution was constructed using the MEGA 4. 0 package. Results The 551 bp 16S rDNA fragment was successfully sequenced for all the specimens. All flies were rightly assigned into seven species with monophyletic separation in the N-J tree. The intraspecific and interspecific variation analyze showed 0 ~ 2. 8% sequence divergence within species and 1. 6

  12. Copy number variation of ribosomal DNA and Pokey transposons in natural populations of Daphnia

    Directory of Open Access Journals (Sweden)

    Eagle Shannon HC

    2012-03-01

    Full Text Available Abstract Background Despite their ubiquity and high diversity in eukaryotic genomes, DNA transposons are rarely encountered in ribosomal DNA (rDNA. In contrast, R-elements, a diverse group of non-LTR retrotransposons, specifically target rDNA. Pokey is a DNA transposon that targets a specific rDNA site, but also occurs in many other genomic locations, unlike R-elements. However, unlike most DNA transposons, Pokey has been a stable component of Daphnia genomes for over 100 million years. Here we use qPCR to estimate the number of 18S and 28S ribosomal RNA genes and Pokey elements in rDNA (rPokey, as well as other genomic locations (gPokey in two species of Daphnia. Our goals are to estimate the correlation between (1 the number of 18S and 28S rRNA genes, (2 the number of 28S genes and rPokey, and (3 the number of rPokey and gPokey. In addition, we ask whether Pokey number and distribution in both genomic compartments are affected by differences in life history between D. pulex and D. pulicaria. Results We found differences in 18S and 28S gene number within isolates that are too large to be explained by experimental variation. In general, Pokey number within isolates is modest (Pokey. There is no correlation between the number of rRNA genes and rPokey, or between rPokey and gPokey. However, we identified three isolates with unusually high numbers of both rPokey and gPokey, which we infer is a consequence of recent transposition. We also detected other rDNA insertions (rInserts that could be degraded Pokey elements, R- elements or the divergent PokeyB lineage recently detected in the Daphnia genome sequence. Unlike rPokey, rInserts are positively correlated with rRNA genes, suggesting that they are amplified by the same mechanisms that amplify rDNA units even though rPokey is not. Overall, Pokey frequency and distribution are similar in D. pulex and D. pulicaria suggesting that differences in life history have no impact on Pokey. Conclusions The

  13. Novel extraction strategy of ribosomal RNA and genomic DNA from cheese for PCR-based investigations.

    Science.gov (United States)

    Bonaïti, Catherine; Parayre, Sandrine; Irlinger, Françoise

    2006-03-15

    Cheese microorganisms, such as bacteria and fungi, constitute a complex ecosystem that plays a central role in cheeses ripening. The molecular study of cheese microbial diversity and activity is essential but the extraction of high quality nucleic acid may be problematic: the cheese samples are characterised by a strong buffering capacity which negatively influenced the yield of the extracted rRNA. The objective of this study is to develop an effective method for the direct and simultaneous isolation of yeast and bacterial ribosomal RNA and genomic DNA from the same cheese samples. DNA isolation was based on a protocol used for nucleic acids isolation from anaerobic digestor, without preliminary washing step with the combined use of the action of chaotropic agent (acid guanidinium thiocyanate), detergents (SDS, N-lauroylsarcosine), chelating agent (EDTA) and a mechanical method (bead beating system). The DNA purification was carried out by two washing steps of phenol-chloroform. RNA was isolated successfully after the second acid extraction step by recovering it from the phenolic phase of the first acid extraction. The novel method yielded pure preparation of undegraded RNA accessible for reverse transcription-PCR. The extraction protocol of genomic DNA and rRNA was applicable to complex ecosystem of different cheese matrices.

  14. Analysis of bacterial diversity of kefir grains by denaturing gradient gel electrophoresis and 16S rDNA sequencing%应用变性梯度凝胶电泳和16S rDNA序列分析对kefir粒中细菌多样性的研究

    Institute of Scientific and Technical Information of China (English)

    王荫榆; 李会荣; 贾士芳; 吴正钧; 郭本恒

    2006-01-01

    以开菲尔(Kefir)粒为材料,经过DNA抽提和16S rDNA V3区PCR扩增,扩增产物经变性梯度凝胶电泳(DGGE)分离并切割电泳条带进行序列测定,并与现有的数据库进行了比较,对Kefir粒的细菌多样性进行分析.结 果表明,DGGE图谱中可检测到的8条带的16S rDNA基因序列中有7个基因序列与GenBank数据库登录的相关序列的相似性大于98%,余下的1个基因序列的相似性也大于96%.相似性大于98%的7个克隆中,有3个属于鞘氨醇杆菌属(Sphingobacterium),2个属于乳杆菌属(Lactobacillus),其它2个分别属于肠杆菌属(Enterobacter)和不动杆菌属(Acinetobacter).首次报道了鞘氨醇杆菌作为优势菌群存在开菲尔Kefir粒中.

  15. [Identification of fish species based on ribosomal DNA ITS2 locus].

    Science.gov (United States)

    Yuan, Wan-An

    2010-04-01

    To prevent illegal fishing and sale, the most difficult problem is identification of marketed fish species, especially the parts that are difficult to be differentiated with morphological method (e.g., larval, eggs, scales, meat, products etc. To assist conservation and management of fishery resources, this paper reported a molecular genetic approach based on ribosomal internal transcribed spacer 2 locus. The method includes two steps: (1) the order general primers were designed according to the conservative nature of 5.8SrRAN and 28SrRNA genes within an order, and the DNA ribosomal internal transcribed spacer 2 locus fragment were then amplified and sequenced. (2) The species-specific ladders and the species-specific primers for each species were designed according to the sequencing results. The map of molecular taxonomy was constructed. This approach employs multiplex PCR that is formatted for fish species identification. We tested 210 single-species samples and 40 mix-species samples from different regions of China. The approach distinguished accurately and sensitively samples from each of the five species. This genetic and molecular approach will be useful for fish conservation, assessment, management and exploitation, strengthen in law enforcement of fishery manager, combat rare and endangered fish smuggling, and prevent commercial fraud and biological invasion by harmful nonnative species.

  16. Are ribosomal DNA clusters rearrangement hotspots? A case study in the genus Mus (Rodentia, Muridae

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    Douzery Emmanuel JP

    2011-05-01

    Full Text Available Abstract Background Recent advances in comparative genomics have considerably improved our knowledge of the evolution of mammalian karyotype architecture. One of the breakthroughs was the preferential localization of evolutionary breakpoints in regions enriched in repetitive sequences (segmental duplications, telomeres and centromeres. In this context, we investigated the contribution of ribosomal genes to genome reshuffling since they are generally located in pericentromeric or subtelomeric regions, and form repeat clusters on different chromosomes. The target model was the genus Mus which exhibits a high rate of karyotypic change, a large fraction of which involves centromeres. Results The chromosomal distribution of rDNA clusters was determined by in situ hybridization of mouse probes in 19 species. Using a molecular-based reference tree, the phylogenetic distribution of clusters within the genus was reconstructed, and the temporal association between rDNA clusters, breakpoints and centromeres was tested by maximum likelihood analyses. Our results highlighted the following features of rDNA cluster dynamics in the genus Mus: i rDNA clusters showed extensive diversity in number between species and an almost exclusive pericentromeric location, ii a strong association between rDNA sites and centromeres was retrieved which may be related to their shared constraint of concerted evolution, iii 24% of the observed breakpoints mapped near an rDNA cluster, and iv a substantial rate of rDNA cluster change (insertion, deletion also occurred in the absence of chromosomal rearrangements. Conclusions This study on the dynamics of rDNA clusters within the genus Mus has revealed a strong evolutionary relationship between rDNA clusters and centromeres. Both of these genomic structures coincide with breakpoints in the genus Mus, suggesting that the accumulation of a large number of repeats in the centromeric region may contribute to the high level of chromosome

  17. Genetic diversity of Colombian sylvatic Trypanosoma cruzi isolates revealed by the ribosomal DNA

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    Cuervo Patricia

    2002-01-01

    Full Text Available American trypanosomiasis is a common zoonosis in Colombia and Trypanosoma cruzi presents a wide distribution throughout the country. Although some studies based on enzyme electrophoresis profiles have described the population structure of the parasite, very few molecular analyses of genotipic markers have been conducted using Colombian strains. In this study, we amplified the non-transcribed spacer of the mini-gene by PCR, typing the isolates as T. cruzi I, T. cruzi zymodeme 3 or T. rangeli. In addition, the internal transcribed spacers of the ribosomal gene concomitant with the 5.8S rDNA were amplified and submitted to restriction fragment polymorphism analysis. The profiles were analyzed by a numerical methodology generating a phenetic dendrogram that shows heterogeneity among the T. cruzi isolates. This finding suggests a relationship between the complexity of the sylvatic transmission cycle in Colombia and the diversity of the sylvan parasites.

  18. Phylogenetic analysis of Bambusa (Poaceae: Bambusoideae) based on internal transcribed spacer sequences of nuclear ribosomal DNA.

    Science.gov (United States)

    Sun, Ye; Xia, Nianhe; Lin, Rushun

    2005-12-01

    Phylogenetic analyses of Bambusa species were performed using internal transcribed spacer sequences of nuclear ribosomal DNA. The 21 species sampled included members of Bambusa (sensu stricto), Dendrocalamopsis, Dendrocalamus, Guadua, Leleba, and Lingnania. Arundinaria gigantea was used as an outgroup. Using the maximum parsimony method with PAUP*, gaps were treated as missing states or new states. Parsimonious analysis revealed that Dendrocalamus latiflorus was closely related to the members of Dendrocalamopsis. Dendrocalamus membranaceus was a sister species to Dendrocalamus strictus. Three Dendrocalamus species were closely related to and nested in a polyphyletic Bambusa. Bambusa subaequalis was a sister species to B. multiplex, B. emeiensis to B. chungii, B. contracta to B. hainanensis, and B. flexuosa was a sister species to B. sinospinosa, B. tuldoides, B. surrecta, B. intermedia, and B. valida group, which raised doubts about the monophyly of the subgenera Bambusa (sensu stricto), Dendrocalamopsis, Leleba, and Lingnania under the genus Bambusa. PMID:16382365

  19. 16S rDNA-based analysis reveals cosmopolitan occurrence but limited diversity of two cyanobacterial lineages with contrasted patterns of intracellular carbonate mineralization

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    Marie eRagon

    2014-07-01

    Full Text Available Cyanobacteria are mainly thought to induce carbonate precipitation extracellularly via their photosynthetic activity combined with the nucleation potential of exopolymeric substances. The discovery in microbialites of the alkaline lake Alchichica (Mexico of Candidatus Gloeomargarita lithophora, a cyanobacterium forming large amounts of intracellular Mg-Ca-Sr-Ba carbonate spherules, showed that intracellular biomineralization in cyanobacteria is also possible. A second cyanobacterium isolated from the same environment, Candidatus Synechococcus calcipolaris G9, has been recently shown to also form intracellular calcium carbonates at the cell poles, a capability shared by all cultured species of the Thermosynechococcus clade, to which it belongs. To explore the diversity of these two distant cyanobacterial lineages representing two different patterns of intracellular calcification, we designed specific primers against their 16S rRNA genes and looked for their occurrence in a wide variety of samples. We identified the presence of members of the Gloeomargarita and Thermosynechococcus/S. calcipolaris lineages in microbialites collected from Lake Alchichica and three other neighboring Mexican lakes. The two clades also occurred in karstic areas and in some thermophilic or hypersaline microbial mats collected in South America and/or Southern Europe. Surprisingly, the within-group diversity in the two clades was low, especially within the S. calcipolaris clade, with all 16S rRNA gene sequences retrieved sharing more than 97% identity. This suggests that these clades are composed of a limited number of species with cosmopolitan distribution. Moreover, scanning electron microscopy coupled with energy dispersive x-ray spectrometry showed the presence of intracellularly calcifying Gloeomargarita-like cyanobacteria in fresh samples where this clade was relatively abundant, suggesting that these cyanobacteria do precipitate carbonates intracellularly under

  20. A Comparison between Transcriptome Sequencing and 16S Metagenomics for Detection of Bacterial Pathogens in Wildlife.

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    Maria Razzauti

    Full Text Available Rodents are major reservoirs of pathogens responsible for numerous zoonotic diseases in humans and livestock. Assessing their microbial diversity at both the individual and population level is crucial for monitoring endemic infections and revealing microbial association patterns within reservoirs. Recently, NGS approaches have been employed to characterize microbial communities of different ecosystems. Yet, their relative efficacy has not been assessed. Here, we compared two NGS approaches, RNA-Sequencing (RNA-Seq and 16S-metagenomics, assessing their ability to survey neglected zoonotic bacteria in rodent populations.We first extracted nucleic acids from the spleens of 190 voles collected in France. RNA extracts were pooled, randomly retro-transcribed, then RNA-Seq was performed using HiSeq. Assembled bacterial sequences were assigned to the closest taxon registered in GenBank. DNA extracts were analyzed via a 16S-metagenomics approach using two sequencers: the 454 GS-FLX and the MiSeq. The V4 region of the gene coding for 16S rRNA was amplified for each sample using barcoded universal primers. Amplicons were multiplexed and processed on the distinct sequencers. The resulting datasets were de-multiplexed, and each read was processed through a pipeline to be taxonomically classified using the Ribosomal Database Project. Altogether, 45 pathogenic bacterial genera were detected. The bacteria identified by RNA-Seq were comparable to those detected by 16S-metagenomics approach processed with MiSeq (16S-MiSeq. In contrast, 21 of these pathogens went unnoticed when the 16S-metagenomics approach was processed via 454-pyrosequencing (16S-454. In addition, the 16S-metagenomics approaches revealed a high level of coinfection in bank voles.We concluded that RNA-Seq and 16S-MiSeq are equally sensitive in detecting bacteria. Although only the 16S-MiSeq method enabled identification of bacteria in each individual reservoir, with subsequent derivation of

  1. Phylogenetic analysis of Sorghum and related taxa using internal transcribed spacers of nuclear ribosomal DNA.

    Science.gov (United States)

    Sun, Y; Skinner, D Z; Liang, G H; Hulbert, S H

    1994-09-01

    The phylogenetic relationships of the genus Sorghum and related genera were studied by sequencing the nuclear ribosomal DNA (rDNA) internal transcribed spacer region (ITS). DNA was extracted from 15 Sorghum accessions, including one accession from each of the sections Chaetosorghum and Heterosorghum, four accessions from Parasorghum, two accessions from Stiposorghum, and seven representatives from three species of the section Sorghum (one accession from each of S. propinquum and S. halepense, and five races of S. bicolor). The maize (Zea mays) line, H95, and an accession from Cleistachne sorghoides were also included in the study. Variable nucleotides were used to construct a strict consensus phylogenetic tree. The analyses indicate that S. propinquum, S. halepense and S. bicolor subsp. arundinaceum race aethiopicum may be the closest wild relatives of cultivated sorghum; Sorghum nitidum may be the closest 2n=10 relative to S. bicolor, the sections Chaetosorghum and Heterosorghum appear closely related to each other and more closely related to the section Sorghum than Parasorghum; and the section Parasorghum is not monophyletic. The results also indicate that the genus Sorghum is a very ancient and diverse group.

  2. The homology analysis of internal transcribed spacer sequence of ribosomal DNA in common dermatophytes

    Institute of Scientific and Technical Information of China (English)

    QIANG WANG; ZHAO HUI JI; HOU MIN LI; LI JUAN ZHANG; WEI LIU; ZHE WAN; XIAO HONG WANG; DUAN LI WANG; RUO YU LI

    2006-01-01

    In order to analyze the sequences of the internal transcribed spacer (ITS) including the 5.8 S ribosomal DNA (rDNA) of common dermatophytes, so as to obtain a rapid and accurate method to identify the species of dermatophytes and to establish the phylogenetic tree of these species to understand their relationship, 16 strains of dermatophytes were collected and preliminarily identified by morphological characteristics. General primers for fungi ITS1 and ITS4 were used to amplify the ITS rDNA of each strains with PCR. The PCR products after purification were sequenced directly and were analyzed through internet. In the results, 11 strains were identified by means of morphological features, among which 5 strains were Trichophyton, 5 strains were Microsporum and 1 was Epidermophyton,which was consistent with the results by molecular biology. In the 5 unidentifiable strains, 1 strain was proved to be Chrysosporium by molecular biology. These strains studied could be divided into 3 different classes as indicated in the analysis of the phylogenetic tree of the sequences in ITS, which were quite different from those of morphological classification. It is evident from the above observations that the molecular method of analysis on the ITS sequences is a rapid, highly sensitive and accurate approach for the detection of dematophyte species, however, it still exhibits some limitations needing the supplementation with morphological identification.

  3. Bacterial diversity in Philippine fermented mustard (burong mustasa) as revealed by 16S rRNA gene analysis.

    Science.gov (United States)

    Larcia, L L H; Estacio, R C; Dalmacio, L M M

    2011-12-01

    Previous studies on the bacterial profile of burong mustasa, a traditional Philippine fermented food, had been conducted using culture-dependent techniques. Since these methods may underestimate the total microbiota of a sample, a culture-independent study was done to determine the bacterial diversity in burong mustasa through molecular biology techniques. Bacterial DNA was isolated from fermented mustard samples at different stages of fermentation. The isolated genomic DNA was amplified by PCR using specific primers for the 16S ribosomal RNA gene (16S rDNA). The 1.5 kb amplicons obtained were subjected to nested PCR using primers for the internal variable region of the 16S rDNA. The 585 bp nested PCR amplicons were then subjected to denaturing gradient gel electrophoresis (DGGE) to separate the different bacteria present in each sample. Distinct and unique bands in the DGGE profile were excised, reamplified, purified and sequenced for bacterial identification. Molecular cloning of the 1.5 kb 16S rDNA was also performed using the pGEM-T Easy Vector System. The cloned gene was sequenced for bacterial identification. The identified microbiota in burong mustasa at different stages of fermentation include lactic acid bacteria and several uncultured bacteria (initial up to the final stages); acetic acid bacteria (middle stage); and Streptobacillus and Fusobacterium species (initial stage). The potential probiotic bacteria found in burong mustasa are Weissella and Lactobacillus. PMID:22146686

  4. A ribosomal RNA gene intergenic spacer based PCR and DGGE fingerprinting method for the analysis of specific rhizobial communities in soil

    NARCIS (Netherlands)

    de Oliveira, VM; Manfio, GP; Coutinho, HLD; Keijzer-Wolters, AC; van Elsas, JD

    2006-01-01

    A direct molecular method for assessing the diversity of specific populations of rhizobia in soil, based on nested PCR amplification of 16S-23S ribosomal RNA gene (rDNA) intergenic spacer (IGS) sequences, was developed. Initial generic amplification of bacterial rDNA IGS sequences from soil DNA was

  5. Cloning and expression of a cDNA encoding ribosomal protein S4 from Rice (Oryza sativa)

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A cDNA clone, pS4, has been isolated from a cDNA library prepared from rice anthers of about 1.0 mm in length. DNA sequence analysis and database search show that the cDNA encodes a protein which is highly homologous to eukaryotic 80S ribosomal protein subunit 4 (S4). Northern hybridization indicates that this gene expresses in all tissues analyzed although the expression level varies and it cannot be induced by mechanical wounding in leaves. Southern blot analysis demonstrates that this rice S4 gene is from a multigene family.

  6. Identification of Trichosporon spp. Strains by Sequencing D1/D2 Region and Sub-typing by Sequencing Ribosomal Intergenic Spacer Region of Ribosomal DNA

    Institute of Scientific and Technical Information of China (English)

    Jingsi ZENG; Cristina Maria de Souza Motta; Kazutaka Fukushima; Kayoko Takizawa; Oliane Maria Correia Magalhes; Rejane Pereira Neves; Kazuko Nishimura

    2009-01-01

    To re-identify and further group 25 isolates of Trichosporon spp. identified morphologically previously, sequences of D1/D2 region of large subunit (LSU) of ribosomal DNA (rDNA) of 25 tested strains for identification and those of ribosomal intergenic space 1 (IGS1) region of 11 strains for sub-grouping were detected. The identifications of tested strains were changed except 6 strains. According to the alignment of the IGS1 region, 6 T. asahii isolates tested fell into 4 groups and 5 T. faecale isolates into 3 groups. Polymorphism of 2 T.japonicum isolates was found in 10 positions. With the alignments obtained in this research compared with the relative GenBank entries, it was found that T. asahii, T.faecale and T.japonicum species were divided into 7, 3 and 2 subtypes respectively. Morphological and biophysical methods are not sufficient for Trichosporon spp. identification. Sequencing becomes neces-sary for Trichosporon diagnosis. There is obvious diversity within a species.

  7. Comparative sequence analyses on the 16S rRNA (rDNA) of Bacillus acidocaldarius, Bacillus acidoterrestris, and Bacillus cycloheptanicus and proposal for creation of a new genus, Alicyclobacillus gen. nov

    Science.gov (United States)

    Wisotzkey, J. D.; Jurtshuk, P. Jr; Fox, G. E.; Deinhard, G.; Poralla, K.

    1992-01-01

    Comparative 16S rRNA (rDNA) sequence analyses performed on the thermophilic Bacillus species Bacillus acidocaldarius, Bacillus acidoterrestris, and Bacillus cycloheptanicus revealed that these organisms are sufficiently different from the traditional Bacillus species to warrant reclassification in a new genus, Alicyclobacillus gen. nov. An analysis of 16S rRNA sequences established that these three thermoacidophiles cluster in a group that differs markedly from both the obligately thermophilic organisms Bacillus stearothermophilus and the facultatively thermophilic organism Bacillus coagulans, as well as many other common mesophilic and thermophilic Bacillus species. The thermoacidophilic Bacillus species B. acidocaldarius, B. acidoterrestris, and B. cycloheptanicus also are unique in that they possess omega-alicylic fatty acid as the major natural membranous lipid component, which is a rare phenotype that has not been found in any other Bacillus species characterized to date. This phenotype, along with the 16S rRNA sequence data, suggests that these thermoacidophiles are biochemically and genetically unique and supports the proposal that they should be reclassified in the new genus Alicyclobacillus.

  8. Variation in Ribosomal DNA among Isolates of the Mycorrhizal Fungus Cenococcum Geophilum FR.

    Science.gov (United States)

    Lobuglio, Katherine Frances

    1990-01-01

    Cenococcum geophilum Fr., a cosmopolitan mycorrhizal fungus, is well-known for its extremely wide host and habitat range. The ecological diversity of C. geophilum sharply contrasts its present taxonomic status as a monotypic form -genus. Restriction fragment length polymorphisms (RFLPs) in nuclear ribosomal DNA (rDNA) was used to assess the degree of genetic variation among 72 isolates of C. geophilum. The probe used in this study was the rDNA repeat cloned from C. geophilum isolate A145 (pCG15). Length of the rDNA repeat was approximately 9 kb. The rDNA clone was mapped for 5 restriction endonucleases. Hybridization with cloned Saccharomyces cerevisiae rDNA (pSR118, and pSR125 containing the 18S, and 5.8-25S rRNA genes respectively), and alignment of restriction endonuclease sites conserved in the rDNA genes of other fungi, were used to position the corresponding rDNAs of C. geophilum. Southern hybridizations with EcoRI, HindIII, XhoI, and PstI digested DNAs indicated extensive variation among the C. geophilum isolates, greater than has been previously reported to occur within a fungal species. Most of the rDNA polymorphisms occurred in the IGS region. Restriction endonuclease site and length polymorphisms were also observed in the 5.8S-26S genic regions. Sixteen size categories of length mutations, 6 restriction endonuclease site additions, and 4 restriction endonuclease site deletions were determined using isolate A145 as a reference. The rDNA repeat length among the isolates varied from approximately 8.5 to 10.2 kb. RFLPs were also observed in the mitochondrial (mt) 24S rRNA gene and flanking regions of HindIII digested DNAs of C. geophilum isolates representing both geographically distinct and similar origins. Among the C. geophilum isolates analyzed there were fewer RFLPs in mt-DNA than in nuclear rDNA. EcoRI rDNA phenotypes between C. geophilum and Elaphomyces anthracinus, its proposed teleomorph or sexual state, did not correspond. In addition, the four

  9. Deterioration to extinction of wastewater bacteria by non-thermal atmospheric pressure air plasma as assessed by 16S rDNA-DGGE fingerprinting

    Directory of Open Access Journals (Sweden)

    Wael Samir El-Sayed

    2015-10-01

    Full Text Available The impact of cold atmospheric plasma on the bacterial community structure of wastewater from two different industries was investigated by metagenomic-based PCR-DGGE utilizing 16S rRNA genes. Three doses of atmospheric pressure dielectric barrier discharge plasma were applied to wastewater samples on different time scales. DGGE revealed that the bacterial community gradually changed and overall abundance decreased to extinction upon plasma treatment. The bacterial community in food processing wastewater contained 11 key operational taxonomic units that remained almost completely unchanged when exposed to plasma irradiation at 75.5 mA for 30 or 60s. However, when exposure time was extended to 90s, only Escherichia coli, Coliforms, Aeromonas sp., Vibrio sp., and Pseudomonas putida survived. Only E. coli, Aeromonas sp., Vibrio sp. and P. putida survived treatment at 81.94 mA for 90s. Conversely, all bacterial groups were completely eliminated by treatment at 85.34 mA for either 60 or 90s. Dominant bacterial groups in leather processing wastewater also changed greatly upon exposure to plasma at 75.5 mA for 30 or 60s, with Enterobacter aerogenes, Klebsiella sp., Pseudomonas stutzeri and Acidithiobacillus ferrooxidans being sensitive to and eliminated from the community. At 90s of exposure, all groups were affected except for Pseudomonas sp. and Citrobacter freundii.

  10. Respiration of 13C-Labeled Substrates Added to Soil in the Field and Subsequent 16S rRNA Gene Analysis of 13C-Labeled Soil DNA

    OpenAIRE

    Padmanabhan, P; Padmanabhan, S.; DeRito, C.; Gray, A; Gannon, D.; Snape, J. R.; Tsai, C. S.; Park, W.; Jeon, C.; Madsen, E.L.

    2003-01-01

    Our goal was to develop a field soil biodegradation assay using 13C-labeled compounds and identify the active microorganisms by analyzing 16S rRNA genes in soil-derived 13C-labeled DNA. Our biodegradation approach sought to minimize microbiological artifacts caused by physical and/or nutritional disturbance of soil associated with sampling and laboratory incubation. The new field-based assay involved the release of 13C-labeled compounds (glucose, phenol, caffeine, and naphthalene) to soil plo...

  11. 16S rDNA序列分析鉴定一株合浦珠母贝共附生乳酸菌%Identification of a symbiotic and epiphyte lactic acid bacterium strain from Pinctada fucata by 16S rDNA sequencing

    Institute of Scientific and Technical Information of China (English)

    张岩; 吴燕燕; 李来好; 杨贤庆; 邵征翌

    2012-01-01

    从合浦珠母贝(Pinctada fucata)粘液中分离纯化得到一株抗菌物质产生菌F9,利用16S rDNA方法鉴定该菌株为棒状乳杆菌(Lactobacillus coryniformis).通过琼脂扩散法测定了该菌的抑菌谱,发现该菌发酵液上清液在排除有机酸和过氧化氢(H2O2)的影响后仍对金黄色葡萄球菌(Staphyloccocus aureus)等多种食源性致病菌有明显的抑菌作用.对该菌发酵液抑菌物质进行超滤分析及蛋白酶处理,可推断该抗菌物质为分子量在5~10 kDa的蛋白类物质.%The strain F9 , which can produce antibacterial substances, was isolated from the Pinctada fucata mucus and finally identified as Lactobacillus coryniformis by 16S rDNA sequence analysis. The antimicrobial spectrum of strain F9 was investigated with agar diffusion method. The results show that the antimicrobial activity of the supernatant is not due to the existence of hydrogen peroxide and organic acid in the solution, and can significantly inhibit various common foodborne pathogens such as Staphyloccocus aureus. It is inferred that the antibacterial substances are proteins with molecular weight of 5 ~ 10 kDa based on ultrafiltration analysis and protease hydrolysis.

  12. Hirudinella ventricosa (Pallas, 1774) Baird, 1853 represents a species complex based on ribosomal DNA.

    Science.gov (United States)

    Calhoun, Dana M; Curran, Stephen S; Pulis, Eric E; Provaznik, Jennifer M; Franks, James S

    2013-10-01

    Digeneans in the genus Hirudinella de Blainville, 1828 (Hirudinellidae) from three species of pelagic fishes, Acanthocybium solandri (Cuvier), Makaira nigricans Lacépède and Thunnus albacares (Bonnaterre), and one benthic fish, Mulloidichthys martinicus (Cuvier), from the Gulf of Mexico are investigated using comparison of ribosomal DNA. Four species are identified based on molecular differences: Hirudinella ventricosa (Pallas, 1774) Baird, 1853 from A. solandri, Hirudinella ahi Yamaguti, 1970 from T. albacares, and two unidentified but distinct species of Hirudinella, herein referred to as Hirudinella sp. A (from both M. nigricans and M. martinicus) and Hirudinella sp. B from M. nigricans. Additionally, H. ahi, based tentatively on morphological identification, is reported from Thunnus thynnus (Linnaeus). This represents the first record of a hirudinellid from M. martinicus and the first record of H. ahi from T. thynnus. A phylogeny of some Hemiurata Skrjabin & Guschanskaja, 1954 using partial fragments of the 28S rDNA sequences is consistent with earlier phylogenies and the position of the Hirudinellidae Dollfus, 1932 is well-supported as a derived group most closely related to the Syncoeliidae Looss, 1899. PMID:24048751

  13. Phylogeny of Deltocephalinae (Hemiptera: Cicadellidae)from China based on partial 16S rDNA and 28S rDNA D2 sequences combined with morphological characters%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)

    Institute of Scientific and Technical Information of China (English)

    戴仁怀; 陈学新; 李子忠

    2008-01-01

    The phylogeny of 19 genera of Deltocephalinae leafhoppers was analyzed based on 50 adult morphological characters combined with nucleotide sequences of the mitochondrial 16S rDNA and nuclear 28S D2 rDNA genes. One species of Typhlocybinae was included as outgroup. Parsimonian, distance and Bayesian methods were used to estimate the phylogenetic relationships. The topology of the phylogenetic trees generated with different methods was quite similar. We partially resolved the morphologically-defined tribes and the relationships among 19 genera of Deltocephalinae. The genus Macrosteles was well supported to occupy a basal position in the study, so the most primary tribe in Deltocephalinae might be Macrostelini. The phylogenetic analysis trees put all genera of Deltocephalini but Nakaharanus onto a single lineage. The genus Balclutha, corresponding to the tribe Balclnthini,remains unsolved in our analyses. The Euscelini might be a polyphyletic group in the analysis. Analytical result recovered Athysanini and Paralimnini as monophyletic clades. The clade Phlogotettix and Scaphoideus-Nakaharanus was constantly resolved using different methods. We suggested that Scaphoideus, Nakaharanus and Phlogotettix should be included in or into Scaphoideini. But the results resolved poorly the taxonomic status of Xestoeephalini overall.%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Tyhlocybinae[半翅目(Hemiptera):叶蝉科(cicadelIidae)]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.O和MrBayes3.0两个分析软件和3种建树方法,利用同源28s D2 rDNA和16srDNA两个基因序列与形态特征结合进行系统发

  14. Identificarion of contaminant bacteria in cachaça yeast by 16s rDNA gene sequencing Identificação de bactérias contaminantes de fermento de cachaça por seqüenciamento do gene 16s rDNA

    Directory of Open Access Journals (Sweden)

    Osmar Vaz de Carvalho-Netto

    2008-01-01

    Full Text Available Cachaça is a typical Brazilian liquor produced from the distillation of fermented sugarcane juice mainly by Saccharomyces cerevisiae. Most of the domestic production is artisanal, and producers usually are not concerned regarding microbiological control of the fermentation. This study aimed to characterize the contaminant bacterial community of the yeast used in the production of cachaça in an artisanal still. Four samples were collected, of which one (NA was used for comparison purposes and was collected one year earlier. The remaining samples were collected at three different periods: at the end of the first day of fermentation (NP, after fifteen days (NS, and thirty days after the same yeast was used (NT. Five hundred and eighty-seven sequences were analyzed from the partial sequencing of the 16S rDNA gene. Sequence analyses revealed the presence of 170 operational taxonomic units (OTUs. Of these, only one was shared among three samples and seventeen were shared between two samples. The remaining 152 OTUs were identified only once in distinct samples indicating that the contaminant bacterial population is highly dynamic along the fermentation process. Statistical analyses revealed differences in bacterial composition among samples. Undescribed species in the literature on yeasts of cachaça were found, such as Weissella cibaria, Leuconostoc citreum, and some species of Lactobacillus, in addition to some unknown bacteria. The community of bacteria in the fermentation process is much more complex than it was previously considered. No previous report is known regarding the use of this technique to determine bacterial contaminants in yeast for the production of cachaça.A cachaça é uma bebida típica brasileira produzida a partir da destilação do caldo de cana-de-açúcar fermentado principalmente por Saccharomyces cerevisiae. Grande parte da produção nacional é artesanal, e não há uma preocupação por parte dos produtores quanto ao

  15. Fecal microbial diversity in pre-weaned dairy calves as described by pyrosequencing of metagenomic 16S rDNA. Associations of Faecalibacterium species with health and growth.

    Directory of Open Access Journals (Sweden)

    Georgios Oikonomou

    Full Text Available In this study, we use barcoded pyrosequencing of the 16S rRNA gene to characterize the fecal microbiota of neonatal calves and identify possible relationships of certain microbiota profiles with health and weight gain. Fecal samples were obtained weekly from 61 calves from birth until weaning (seventh week of the calves' life. Firmicutes was the most prevalent phylum, with a prevalence ranging from 63.84% to 81.90%, followed by Bacteroidetes (8.36% to 23.93%, Proteobacteria (3.72% to 9.75%, Fusobacteria (0.76% to 5.67%, and Actinobacteria (1.02% to 2.35%. Chao1 index gradually increased from the first to the seventh postnatal week. Chao1 index was lower during the third, fourth, and fifth week of life in calves that suffered from pneumonia and were treated with antibiotics. Diarrhea incidence during the first four weeks of the calves' life was also associated with a reduction of microbial diversity during the third week of life. Increased fecal microbial diversity after the second week of life was associated with higher weight gain. Using discriminant analysis we were able to show differences in the microbiota profiles between different weeks of life, between high and low weight gain groups of calves, and between calves affected and not affected with diarrhea during the first four weeks life. The prevalence of Faecalibacterium spp. in the first week of life was associated with weight gain and the incidence of diarrhea, with higher prevalence being associated with higher weight gain and less diarrhea. Representative sequences from Faecalibacterium spp. were closely affiliated to Faecalibacterium prausnitzii. Results presented here provide new information regarding the intestinal microbiota of neonatal calves and its association with health and growth. Fecal microbial diversity was associated with calf age, disease status and growth rates. Results suggesting a possible beneficial effect of Faecalibacterium spp. on health and growth are promising.

  16. Analysis of endophytic bacterial communities of potato by plating and denaturing gradient gel electrophoresis (DGGE) of 16S rDNA based PCR fragments

    NARCIS (Netherlands)

    Garbeva, P.; Overbeek, van L.S.; Vuurde, van J.W.L.; Elsas, van J.D.

    2001-01-01

    The diversity of endophytic bacterial populations of potato (Solanum tuberosum cv Desiree) was assessed using a combination of dilution plating of plant macerates followed by isolation and characterization of isolates, and direct PCR-DGGE on the basis of DNA extracted from plants. The culturable end

  17. Diversitas Genetik Anopheles balabacensis, Baisas di Berbagai Daerah Indonesia Berdasarkan Sekuen Gen ITS 2 DNA Ribosom

    Directory of Open Access Journals (Sweden)

    Widiarti Widiarti

    2016-05-01

    Full Text Available AbstractMalaria control is remain a challenge although various attempts have been conducted. One of the issues in controlling the vectors is the presence of species complex. The species complex is an example of genetic diversity. Anopheles balabacensis, Baisas reported as complex species in various countries, but has not been widely reported in Indonesia. In order to enhance malaria control, it is important to understand the vectors and its bioecology. The aim of the study were a. to identify An. balabacensis, Baisas suspected as species complex based on ribosomal DNA the second internal transcribed spacer (ITS2 gene sequences, b. to understand the genetic diversity of An. balabacensis, Baisas collected from endemic and non endemic regions distincted by geographical distance, c. to understand the genetic relationships (taxonomi distance among An. balabacensis, Baisas from difference regions in Indonesia through reconstructing the phylogenetic trees. The results showed that An. balabacensis, Baisas in Indonesia is identified as sympatric and allopatrik complex species. There were differences which was far enough in the genetic relationships among An. balabacensis populations collected from Pusuk Lestari in the area of Meninting Health Center, West Lombok, NTB. This differences were identified as sympatric complex. In addition, base on the relationship among An. leucosphyrus group, An balabacensis, Baisas collected from Berjoko Nunukan Regency showed that the species quite far compare to An. balabacensis, Baisas originally from Central Java and Lombok NTB.Keywords : An. balabacensis, genetic variation, the second Internal Transcribed Spacer (ITS2.AbstrakPenanggulangan malaria masih banyak menemui kendala walaupun berbagai upaya telah dilakukan. Salah satu kendala yang menyulitkan dalam pengendalian vektor adalah adanya spesies kompleks pada populasi nyamuk vektor. Spesies kompleks merupakan contoh diversitas genetik. Anopheles balabacensis

  18. [Sequence of the ITS region of nuclear ribosomal DNA(nrDNA) in Xinjiang wild Dianthus and its phylogenetic relationship].

    Science.gov (United States)

    Zhang, Lu; Cai, You-Ming; Zhuge, Qiang; Zou, Hui-Yu; Huang, Min-Ren

    2002-06-01

    Xinjiang is a center of distribution and differentiation of genus Dianthus in China, and has a great deal of species resources. The sequences of ITS region (including ITS-1, 5.8S rDNA and ITS-2) of nuclear ribosomal DNA from 8 species of genus Dianthus wildly distributed in Xinjiang were determined by direct sequencing of PCR products. The result showed that the size of the ITS of Dianthus is from 617 to 621 bp, and the length variation is only 4 bp. There are very high homogeneous (97.6%-99.8%) sequences between species, and about 80% homogeneous sequences between genus Dianthus and outgroup. The sequences of ITS in genus Dianthus are relatively conservative. In general, there are more conversion than transition in the variation sites among genus Dianthus. The conversion rates are relatively high, and the ratios of conversion/transition are 1.0-3.0. On the basis of phylogenetic analysis of nucleotide sequences the species of Dianthus in China would be divided into three sections. There is a distant relationship between sect. Barbulatum Williams and sect. Dianthus and between sect. Barbulatum Williams and sect. Fimbriatum Williams, and there is a close relationship between sect. Dianthus and sect. Fimbriatum Williams. From the phylogenetic tree of ITS it was found that the origin of sect. Dianthusis is earlier than that of sect. Fimbriatum Williams and sect. Barbulatum Williams.

  19. Extraction of Bacterial Genomic DNA from Cerebrospinal Fluid of Bacterial Meningitis Patients and Identification of 16S rDNA%细菌性脑膜炎患者脑脊液细菌基因组DNA的提取及16SrDNA的鉴定

    Institute of Scientific and Technical Information of China (English)

    梁志娟; 侯晓霖; 王振海; 刘爱翠

    2013-01-01

    Objective To investigate the application of 16S rDNA as a diagnostic tool for bacterial meningitis . Methods The cerebrospinal fluid (CSF) samples were harvested from patients clinically suspected of bacterial meningitis . Bacterial genomic DNA in the CSF was extracted after bacterial enrichment by high-speed centrifugation. Then PCR amplification of 16S rDNA fragment was performed. The results of PCR amplification were compared with those of bacterial culture. Results Twenty-three of the 58 (39.7% ) cases were positive for 16S rDNA in PCR amplification ,which was significantly higher than the positive rate of bacterial culture with only 10 positive cases (17. 2% )(P<0. 05 ). Conclusion The DNA extraction and 16S rDNA PCR detection are simple procedures with short time consumption and high sensitivity suggesting their good application prospect in etio-logical diagnosis of bacterial meningitis.%目的 探讨16S rDNA聚合酶链式反应(PCR)在细菌性脑脊液病原菌检查中的应用价值.方法 收集临床疑诊为细菌性脑膜炎的患者脑脊液标本,高速离心富集细菌后,进行脑脊液中细菌基因组DNA的提取,再进行16S rDNA PCR扩增和琼脂糖凝胶电泳.将检测结果与传统的细菌培养结果进行比较.结果 58例患者脑脊液样本中,23例16S rDNA PCR阳性,阳性率为39.7%;58例脑脊液样本中细菌培养阳性为10例,阳性率为17.2%.PCR检测阳性率明显高于传统的细菌分离培养法(P<0.05).结论 脑脊液细菌基因组DNA提取及16S rDNA PCR鉴定技术操作简单,耗时短,灵敏度高,在细菌性脑膜炎病原学诊断方面具有良好的应用前景.

  20. 利用16S rDNA 检测奶牛乳房炎5种病原菌PCR 方法的建立及应用%Detection of Five Bacterial Species in Bovine M astitis by PCR Based on 16S rDN A Sequence

    Institute of Scientific and Technical Information of China (English)

    李栋梁; 寇亚楠; 宋月; 魏战勇; 王亚宾

    2014-01-01

    为建立快速检测引起奶牛乳房炎5种病原菌的方法,参照GenBank发表的产气荚膜梭菌、乳酸乳球菌、变形杆菌、绿脓杆菌、肠球菌序列,分别根据其16S rDN A 保守序列区间设计5对引物,进行PCR扩增。结果显示:这5对引物均能针对自身菌株扩增出目的条带,且具有较强的特异性;产气荚膜梭菌、乳酸乳球菌、变形杆菌、绿脓杆菌、肠球菌菌液D N A的最低检测量分别为3.40、0.89、0.91、3.30、3.60 ng/μL ;对临床采集的疑似患有乳房炎的奶牛所产的牛奶样品进行检测,结果显示,与传统的细菌分离鉴定相比,新建立的方法具有灵敏、高效的特性。%According to 16S rDNA conserved sequence ,referring to the GenBank sequence ,this test designed five pairs of primers ,established a PCR assay for detection of five kinds of bovine mastitis pathogens .Experimental results showed that :Five pairs of primers for their own strains could amplify positive bands ,and possessed high specificity .Sensitivity test showed that the prim-ers were able to detect Clostridium perfringens ,Lactococcus lactis ,Proteusbacillus vulgaris ,Pseudo-monas aeruginosa and Enterococcus bacteria DNA concentration of 3.40 ,0.89 ,0.91 ,3.30 ,3.60 ng/μL . The method was used to detect milk samples which was collected from suspected clinical mastitis cows . Compared with the traditional bacteria isolation and identification method ,the new method had the advan-tages of sensitivity and efficient .The results show that the new method is sensitive to detect cow mastitis pathogen and can be used in clinical practice .

  1. Who are the active players of the Iberian Margin deep biosphere? Microbial diversity of borehole U1385 through analysis of 16S rDNA and rRNA

    Science.gov (United States)

    Russell, J. A.; Orsi, W.; Edgcomb, V. P.; Biddle, J.

    2013-12-01

    Microbial community structure and activity in marine deep subsurface environments across the globe have been assayed using various molecular biology tools including 16S rDNA sequencing, microarrays, FISH/CARD-FISH, and metagenomics. Many studies involving these techniques are DNA-based. This limits study of microbial function in these environments as DNA does not degrade as quickly as RNA and may lead to misinterpreting relic microbial genes as important for present-day activity. In this study, the diversity of bacteria and archaea from sediments of the Iberian Margin IODP borehole U1385 was analyzed from bulk extracted DNA and RNA at seven different depths ranging from 10 to 123 meters below seafloor (mbsf). Presented data suggests that the picture of microbial diversity obtained from DNA is markedly different from that seen through analysis of RNA. IODP borehole U1385 offers a great comparison to ODP Site 1229, a well characterized borehole on the Peru Margin. Similar sediment depositional history and geochemistry will allow exploration of what represents a 'typical' continental margin sediment microbial community or if microbial endemism is established despite similar conditions. This study represents the first molecular exploration of sediment microbial communities from the Iberian Margin IODP Site U1385.

  2. Analysis of 22 Strains of Nitrogen-fixing Filamentous Cyanobacteria with Heterocyst by Using PCR-RFLP of 16S rDNA%22种丝状异型胞固氮蓝细菌的16S rDNA的 PCR-RFLP 分析

    Institute of Scientific and Technical Information of China (English)

    陈坚; 吴忠兴; 郑伟文

    2002-01-01

    用1对引物CYA106F及781R(a)从23种蓝细菌的DNA中扩增出一条600 bp的16S rDNA-PCR片段.对该片段进行的限制性酶切长度多态性(RFLP)分析表明:可将其中21种自生或共生的丝状异型胞固氮蓝细菌的样品分为2个类群组,基本上对应于形态分类上的Anabaena及Nostoc属.但有1种被认为是Anabaena的蓝细菌以及作为对照的1种聚球藻(Synechococcus)蓝细菌样品被明显区分出来,并发现Anabaena属的蓝细菌也可同被子植物根乃拉草(Gunnera)形成共生固氮作用.

  3. Design of Vibrio 16S rRNA Gene Specific Primers and Their Application in the Analysis of Seawater Vibrio Community

    Institute of Scientific and Technical Information of China (English)

    LIU Yong; YANG Guanpin; WANG Hualei; CHEN Jixiang; SHI Xianming; ZOU Guiwei; WEI Qiwei; SUN Xiuqin

    2006-01-01

    The pathogenic species of genus Vibrio cause vibriosis, one of the most prevalent diseases of maricultured animals and seafood consumers. Monitoring their kinetics in the chain of seafood production, processing and consumption is of great importance for food and mariculture safety. In order to enrich Vibrio-representing 16S ribosomal RNA gene (rDNA) fragments and identify these bacteria further real-timely and synchronously among bacterial flora in the chain, a pair of primers that selectively amplify Vibrio 16S rDNA fragments were designed with their specificities and coverage testified in the analysis of seawater Vibrio community. The specificities and coverage of two primers, VF169 and VR744, were determined theoretically among bacterial 16S rDNAs available in GenBank by using BLAST program and practically by amplifying Vibrio 16S rDNA fragments from seawater DNA. More than 88.3% of sequences in GenBank, which showed identical matches with VR744, belong to Vibrio genus. A total of 33 clones were randomly selected and sequenced. All of the sequences showed their highest similarities to and clustered around those of diverse known Vibrio species. The primers designed are capable of retrieving a wide range of Vibrio 16S rDNA fragments specifically among bacterial flora in seawater, the most important natural environment of seafood cultivation.

  4. Main airborne Ascomycota spores: characterization by culture, spore morphology, ribosomal DNA sequences and enzymatic analysis.

    Science.gov (United States)

    Oliveira, Manuela; Amorim, M Isabel; Ferreira, Elsa; Delgado, Luís; Abreu, Ilda

    2010-04-01

    The aim of this work was to identify the main allergy-related Ascomycetes fungal spores present in the atmosphere of Porto, using different and complementary techniques. The atmospheric sampling, performed in the atmosphere of Porto (Portugal) from August 2006 to July 2008, indicated Cladosporium, Penicillium, Aspergillus and Alternaria as the main fungal spore taxa. Alternaria and Cladosporium peaks were registered during summer. Aspergillus and Penicillium highest values were registered from late winter to early spring. Additionally, the Andersen sampler allowed the culture and isolation of the collected viable spores subsequently used for different identification approaches. The internal-transcribed spacer region of the nuclear ribosomal repeat unit sequences of airborne Ascomycetes fungi isolates revealed 11 taxonomically related fungal species. Among the identified taxa, Penicillum and Aspergillus presented the highest diversity, while only one species of Cladosporium and Alternaria, respectively, were identified. All selected fungal spore taxa possessed phosphatase, esterase, leucine arylamidase and beta-glucosidase enzymatic activity, while none had lipase, cystine arylamidase, trypsin or beta-glucuronidase activity. The association between the spore cell wall morphology, DNA-based techniques and enzymatic activity approaches allowed a more reliable identification procedure of the airborne Ascomycota fungal spores. PMID:20143229

  5. Phylogenetic analysis of Pectinidae (Bivalvia) based on the ribosomal DNA internal transcribed spacer region

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The ribosomal DNA internal transcribed spacer (ITS) region is a useful genomic region for understanding evolutionary and genetic relationships. In the current study, the molecular phylogenetic analysis of Pectinidae (Mollusca: Bivalvia) was performed using the nucleotide sequences of the nuclear ITS region in nine species of this family. The sequences were obtained from the scallop species Argopecten irradians, Mizuhopecten yessoensis, Amusium pleuronectes and Mimachlamys nobilis, and compared with the published sequences of Aequipecten opercularis, Chlamys farreri, C. distorta, M. varia, Pecten maximus, and an outgroup species Perna viridis. The molecular phylogenetic tree was constructed by the neighbor-joining and maximum parsimony methods. Phylogenetic analysis based on ITS1, ITS2, or their combination always yielded trees of similar topology. The results support the morphological classifications of bivalve and are nearly consistent with classification of two subfamilies (Chlamydinae and Pectininae) formulated by Waller. However, A. irradians, together with A. opercularis made up of genera Amusium, evidences that they may belong to the subfamily Pectinidae. The data are incompatible with the conclusion of Waller who placed them in Chlamydinae by morphological characteristics. These results provide new insights into the evolutionary relationships among scallop species and contribute to the improvement of existing classification systems.

  6. Origin and relationships of Saintpaulia (Gesneriaceae) based on ribosomal DNA internal transcribed spacer (ITS) sequences.

    Science.gov (United States)

    Moller, M; Cronk, Q

    1997-07-01

    Phylogenetic relationships of eight species of Saintpaulia H. Wendl., 19 species of Streptocarpus Lindl. (representing all major growth forms within the genus), and two outgroups (Haberlea rhodopensis Friv., Chirita spadiciformis W. T. Wang) were examined using comparative nucleotide sequences from the two internal transcribed spacers (ITS) of nuclear ribosomal DNA. The length of the ITS 1 region ranged from 228 to 249 base pairs (bp) and the ITS 2 region from 196 to 245 bp. Pairwise sequence divergence across both spacers for ingroup and outgroup species ranged from 0 to 29%. Streptocarpus is not monophyletic, and Saintpaulia is nested within Streptocarpus subgenus Streptocarpella. Streptocarpus subgenus Streptocarpus is monophyletic. The ITS sequence data demonstrate that the unifoliate Streptocarpus species form a clade, and are also characterized by a unique 47-bp deletion in ITS 2. The results strongly support the monophyly of (1) Saintpaulia, and (2) Saintpaulia plus the African members of the subgenus Streptocarpella of Streptocarpus. The data suggest the evolution of Saintpaulia from Streptocarpus subgenus Streptocarpella. The differences in flower and vegetative characters are probably due to ecological adaptation leading to a relatively rapid radiation of Saintpaulia. PMID:21708650

  7. 大白菜软腐病菌16S rDNA序列比对鉴定及杀菌剂对其生物活性测定试验%16S rDNA Sequence Compare of Erwinia carotovora subsp, carotovora and Bioactivity of Fungicide against Chinese Cabbage Soft Rot

    Institute of Scientific and Technical Information of China (English)

    陈亮; 刘君丽; 司乃国

    2011-01-01

    [Aims] Erwinia carotovora subsp. Carotovora is an important plant disease having effect on the normal growth of Chinese cabbage, which seriously results in decreasing crop's yield and quality. Chemical control is an effective messure to control the disease. In order to clarify the controlling effect of strobilurins and antibiotics on Erwinia carotovora subsp. Carotovora, the research was carried out. [Methods] E. Carotovora subsp. Carotovora separated from the leaf of rotten Chinese cabbage was identified using method of sequence comparison to 16S rDNA, and then bioactivity of the fungicides mentioned above was tested using E. Carotovora subsp. Carotovora as target. [Results] The results indicated that there was great bioactivity difference between different fungicides for E. Carotovora subsp. Carotovora, the results of in vitro and in vivo are different for the same fungicide. [Conclusions] Due to the bioactivity difference between in vitro and in vivo, these two testing methods, in vivo and in vitro should be evaluated together to obtain accurate evaluation.%[目的]大白菜软腐病是影响白菜正常生长的重要病害,严重影响白菜的产量和品质.化学防治是控制大白菜软腐病的重要措施.为了进一步明确甲氧基丙烯酸酯类和抗生素类药剂对大白菜软腐病的防治效果,开展试验研究.[方法]从腐烂大白菜叶片分离得到大白菜软腐病菌(Erwinia carotovora subsp.carotovora),采用16S rDNA序列比对的方法对其进行鉴定.将其作为防治对象,测试杀菌剂的生物活性.[结果]不同药剂对大白菜软腐病菌的生物活性差异很大,同一药剂在离体试验和活体试验中的结果也并不相同.[结论]由于药剂的生物活性测试结果在离体和活体试验中表现出差异性,需要将2种试验方法相结合,才能对药剂生物活性进行准确评价.

  8. Pseudanoplocephala crawfordi is a member of genus Hymenolepis based on phylogenetic analysis using ribosomal and mitochondrial DNA sequences.

    Science.gov (United States)

    Jia, Yan-Qing; Yan, Wen-Chao; Du, Shuai-Zhi; Song, Jun-Ke; Zhao, Wen; Zhao, Yu-Xin; Cheng, Wen-Yu; Zhao, Guang-Hui

    2016-05-01

    Pseudanoplocephala crawfordi is one of the important zoonotic cestodes causing economic significance and public health concern. In the present study, the phylogenetic position of P. crawfordi isolated from pigs was re-inferred using molecular markers of internal transcribed spacer ribosomal DNA (ITS rDNA) and partial NADH dehydrogenase subunit 1 (pnad1) mitochondrial DNA. The lengths of ITS1, ITS2 rDNA and pnad1 were 757 bp, 628 bp and 458 bp, respectively. Sequence differences in the ITS1, ITS2 rDNA and pnad1 between P. crawfordi and Hymenolepis species were smaller than that between cestodes within genus Hymenolepis. Phylogenetic analyses based on three gene fragments showed that P. crawfordi was grouped into cluster of Hymenolepis species. These results suggested that P. crawfordi would be one member of genus Hymenolepis but not in a new genus Pseudanoplocephala.

  9. Heterochromatin patterns and ribosomal DNA loci distribution in diploid and polyploid Crotalaria species (Leguminosae, Papilionoideae), and inferences on karyotype evolution.

    Science.gov (United States)

    Mondin, Mateus; Aguiar-Perecin, Margarida L R

    2011-09-01

    Most Crotalaria species display a symmetric karyotype with 2n = 16, but 2n = 14 is found in Chrysocalycinae subsection Incanae and 2n = 32 in American species of the section Calycinae. Seven species of the sections Chrysocalycinae, Calycinae, and Crotalaria were analyzed for the identification of heterochromatin types with GC- and AT-specific fluorochromes and chromosomal location of ribosomal DNA loci using fluorescent in situ hybridization (FISH). A major 45S rDNA locus was observed on chromosome 1 in all the species, and a variable number of minor ones were revealed. Only one 5S rDNA locus was observed in the species investigated. Chromomycin A(3) (CMA) revealed CMA(+) bands colocalized with most rDNA loci, small bands unrelated to ribosomal DNA on two chromosome pairs in Crotalaria incana, and CMA(+) centromeric bands that were quenched by distamycin A were detected in species of Calycinae and Crotalaria sections. DAPI(+) bands were detected in C. incana. The results support the species relationships based on flower specialization and were useful for providing insight into mechanisms of karyotype evolution. The heterochromatin types revealed by fluorochromes suggest the occurrence of rearrangements in repetitive DNA families in these heterochromatic blocks during species diversification. This DNA sequence turnover and the variability in number/position of rDNA sites could be interpreted as resulting from unequal crossing over and (or) transposition events. The occurrence of only one 5S rDNA locus and the smaller chromosome size in the polyploids suggest that DNA sequence losses took place following polyploidization events.

  10. Heterochromatin patterns and ribosomal DNA loci distribution in diploid and polyploid Crotalaria species (Leguminosae, Papilionoideae), and inferences on karyotype evolution.

    Science.gov (United States)

    Mondin, Mateus; Aguiar-Perecin, Margarida L R

    2011-09-01

    Most Crotalaria species display a symmetric karyotype with 2n = 16, but 2n = 14 is found in Chrysocalycinae subsection Incanae and 2n = 32 in American species of the section Calycinae. Seven species of the sections Chrysocalycinae, Calycinae, and Crotalaria were analyzed for the identification of heterochromatin types with GC- and AT-specific fluorochromes and chromosomal location of ribosomal DNA loci using fluorescent in situ hybridization (FISH). A major 45S rDNA locus was observed on chromosome 1 in all the species, and a variable number of minor ones were revealed. Only one 5S rDNA locus was observed in the species investigated. Chromomycin A(3) (CMA) revealed CMA(+) bands colocalized with most rDNA loci, small bands unrelated to ribosomal DNA on two chromosome pairs in Crotalaria incana, and CMA(+) centromeric bands that were quenched by distamycin A were detected in species of Calycinae and Crotalaria sections. DAPI(+) bands were detected in C. incana. The results support the species relationships based on flower specialization and were useful for providing insight into mechanisms of karyotype evolution. The heterochromatin types revealed by fluorochromes suggest the occurrence of rearrangements in repetitive DNA families in these heterochromatic blocks during species diversification. This DNA sequence turnover and the variability in number/position of rDNA sites could be interpreted as resulting from unequal crossing over and (or) transposition events. The occurrence of only one 5S rDNA locus and the smaller chromosome size in the polyploids suggest that DNA sequence losses took place following polyploidization events. PMID:21864195

  11. Comparative study of mtDNA 16S rRNA gene fragments among six Lutjanus fishes%6种笛鲷属鱼类线粒体16SrRNA基因片段的序列比较

    Institute of Scientific and Technical Information of China (English)

    周发林; 江世贵; 苏天凤; 吕俊霖

    2004-01-01

    对笛鲷属(Lutjanus)的紫红笛鲷(Lutjanus argentimaculatus)、白星笛鲷(Lutjanus stellatus)、千年笛鲷(Lutjanus sebae)、勒氏笛鲷(Lutjanus russellii)、红鳍笛鲷(Lutjanus erythropterus)线粒体DNA 16S rRNA 基因片段进行了PCR 扩增和测序,得到长度约418 bp的序列.结合GenBank中斜带笛鲷(Lutjanus decussatus)该区段的16S rRNA序列,用Clustal_X排序软件进行16S rRNA序列的对位排列.通过Mega 2.1软件对所得线粒体16S rRNA片段序列进行比较,共检测53个碱基存在变异,其中包括21个简约信息位点,并用"Pairwise distance"计算了各属间的相对遗传距离,结果表明,其序列差异(转换+颠换)在0.027~0.083,其中勒氏笛鲷与斜带笛鲷的序列差异最小, 红鳍笛鲷与勒氏笛鲷的序列差异最大.以高体四长棘鲷(Argyrops spinifer)为外类群,采用Mega 2.1软件中的"Neighbore-Joining"法得到唯一1个分子系统树,系统树各分支的置信度由"Bootstrap"1000 循环检验.结果表明,6种笛鲷鱼类聚成明显的3个分支,第1个分支,包括勒氏笛鲷、斜带笛鲷和白星笛鲷;第2个分支,包括紫红笛鲷;第3个分支,包括红鳍笛鲷和千年笛鲷.

  12. Nucleotide sequence of cDNA coding for dianthin 30, a ribosome inactivating protein from Dianthus caryophyllus.

    Science.gov (United States)

    Legname, G; Bellosta, P; Gromo, G; Modena, D; Keen, J N; Roberts, L M; Lord, J M

    1991-08-27

    Rabbit antibodies raised against dianthin 30, a ribosome inactivating protein from carnation (Dianthus caryophyllus) leaves, were used to identify a full length dianthin precursor cDNA clone from a lambda gt11 expression library. N-terminal amino acid sequencing of purified dianthin 30 and dianthin 32 confirmed that the clone encoded dianthin 30. The cDNA was 1153 basepairs in length and encoded a precursor protein of 293 amino acid residues. The first 23 N-terminal amino acids of the precursor represented the signal sequence. The protein contained a carboxy-terminal region which, by analogy with barley lectin, may contain a vacuolar targeting signal.

  13. Application of 16S rDNA sequencing technique in infantile intestinal microecological research%16SrDNA测序技术在婴儿肠道微生态研究中的应用

    Institute of Scientific and Technical Information of China (English)

    马丽亚; 王辉林; 陈睿; 张敏; 黄艳; 卢光进

    2015-01-01

    目的:探讨16S rDNA测序技术在新生儿、婴儿肠道微生态研究中的应用。方法于生后3天、1月、6月、1岁时收集2例健康婴儿粪便标本共8份,提取细菌总DNA ,以Illumina Hiseq 2000为测序平台,采用新一代高通量16S rDNA宏基因组测序技术对V6可变区测序,并进行生物信息分析(物种分类和丰度分析;多样性分析)。结果8份样品共产生原始测序数据为1027.47 Mbp ,Unique tags序列数量均值为58630,OTU数量63~209;优势菌门为Proteobacteria和Firmicutes ;在科水平,>1%的物种1个月之内2~4种,6月后达7~10种;1号婴儿一直以Enterobacteriaceae占优势,2号婴儿优势菌群包括 Enterobacteriaceae、Lachnospiraceae、Streptococcaceae和Bacteroidaceae;4个时间点的npShannon和Simpson指数分别为1.17、1.29、2.16、2.51和0.43、0.40、0.26、0.14。结论16S rDNA测序技术能满足新生儿、婴儿肠道微生态研究需求;新生儿、婴儿粪便中含丰富细菌基因组;细菌物种丰度及分类存在个体差异;从出生到1岁,婴儿肠道菌群结构趋向复杂和多样。%Objective To investigate the application of 16S rDNA sequencing technique in studying intestinal microecology of neonates and infants .Methods Eight fecal samples were collected on 3 d ,1 month ,6 months and 1 year in 2 healthy infants .Total bacterial DNAs were extracted and submitted the high throughout 16S rDNA sequen‐cing on the V6 viable region by using Illumia genome analyzer Hiseq 2000 (101 bp pair‐end sequencing strategy) .The 16S rDNA tags and operational taxonomic units (OTU) were then obtained from the sequences .The bioinformatic a‐nalysis including analysis of taxonomy ,abundance and alpha diversity were performed .Results Total 1 027 .47 Mbp raw data were produced .The mean unique tags number was 58630 .The OTU numbers ranged from 36 to 308 .The bacterial families more than 1% were increased

  14. 16SrDNA测序技术在婴儿肠道微生态研究中的应用%Application of 16S rDNA sequencing technique in infantile intestinal microecological research

    Institute of Scientific and Technical Information of China (English)

    马丽亚; 王辉林; 陈睿; 张敏; 黄艳; 卢光进

    2015-01-01

    目的:探讨16S rDNA测序技术在新生儿、婴儿肠道微生态研究中的应用。方法于生后3天、1月、6月、1岁时收集2例健康婴儿粪便标本共8份,提取细菌总DNA ,以Illumina Hiseq 2000为测序平台,采用新一代高通量16S rDNA宏基因组测序技术对V6可变区测序,并进行生物信息分析(物种分类和丰度分析;多样性分析)。结果8份样品共产生原始测序数据为1027.47 Mbp ,Unique tags序列数量均值为58630,OTU数量63~209;优势菌门为Proteobacteria和Firmicutes ;在科水平,>1%的物种1个月之内2~4种,6月后达7~10种;1号婴儿一直以Enterobacteriaceae占优势,2号婴儿优势菌群包括 Enterobacteriaceae、Lachnospiraceae、Streptococcaceae和Bacteroidaceae;4个时间点的npShannon和Simpson指数分别为1.17、1.29、2.16、2.51和0.43、0.40、0.26、0.14。结论16S rDNA测序技术能满足新生儿、婴儿肠道微生态研究需求;新生儿、婴儿粪便中含丰富细菌基因组;细菌物种丰度及分类存在个体差异;从出生到1岁,婴儿肠道菌群结构趋向复杂和多样。%Objective To investigate the application of 16S rDNA sequencing technique in studying intestinal microecology of neonates and infants .Methods Eight fecal samples were collected on 3 d ,1 month ,6 months and 1 year in 2 healthy infants .Total bacterial DNAs were extracted and submitted the high throughout 16S rDNA sequen‐cing on the V6 viable region by using Illumia genome analyzer Hiseq 2000 (101 bp pair‐end sequencing strategy) .The 16S rDNA tags and operational taxonomic units (OTU) were then obtained from the sequences .The bioinformatic a‐nalysis including analysis of taxonomy ,abundance and alpha diversity were performed .Results Total 1 027 .47 Mbp raw data were produced .The mean unique tags number was 58630 .The OTU numbers ranged from 36 to 308 .The bacterial families more than 1% were increased

  15. Analysis of the bacterial diversity in the intestine of larval Procecidochares utilis (Diptera: Trypetidae) based on 16S rDNA gene sequence%基于16S rDNA基因序列的泽兰实蝇幼虫肠道细菌多样性分析

    Institute of Scientific and Technical Information of China (English)

    张某; 杨璞; 朱家颖; 袁远; 桂富荣; 高熹; 吴国星

    2016-01-01

    [目的]探究泽兰实蝇Procecidochares utilis幼虫肠道细菌的多样性.[方法]利用Illumina HiSeq技术对泽兰实蝇幼虫肠道细菌的16S rDNA-V6变异区序列进行测序,应用USEARCH和QIIME等软件整理和统计样品序列数目和操作分类单元(operational taxonomic unit,OTU)数量,分析物种的丰度和Alpha多样性.[结果]共获得1 593 506对reads,拼接为1 579 372条tags,经过滤后得到的1 572 860条tags聚类为1 341个OTU.总共注释到13个门,4个纲,6个目,7个科,10个属和4个种.其中变形菌门(Proteobacteria)的细菌为优势菌,占99%;在属分类阶元上,沃尔巴克氏体属Wolbachia占45%,是优势属.[结论]泽兰实蝇幼虫肠道细菌多样性丰富.相关的种类和丰度信息为后期研究揭示肠道细菌介导泽兰实蝇寄主植物专化性奠定了基础.

  16. 基于16S rDNA基因序列的泽兰实蝇幼虫肠道细菌多样性分析%Analysis of the bacterial diversity in the intestine of larval Procecidochares utilis (Diptera: Trypetidae) based on 16S rDNA gene sequence

    Institute of Scientific and Technical Information of China (English)

    张某; 杨璞; 朱家颖; 袁远; 桂富荣; 高熹; 吴国星

    2016-01-01

    [目的]探究泽兰实蝇Procecidochares utilis幼虫肠道细菌的多样性.[方法]利用Illumina HiSeq技术对泽兰实蝇幼虫肠道细菌的16S rDNA-V6变异区序列进行测序,应用USEARCH和QIIME等软件整理和统计样品序列数目和操作分类单元(operational taxonomic unit,OTU)数量,分析物种的丰度和Alpha多样性.[结果]共获得1 593 506对reads,拼接为1 579 372条tags,经过滤后得到的1 572 860条tags聚类为1 341个OTU.总共注释到13个门,4个纲,6个目,7个科,10个属和4个种.其中变形菌门(Proteobacteria)的细菌为优势菌,占99%;在属分类阶元上,沃尔巴克氏体属Wolbachia占45%,是优势属.[结论]泽兰实蝇幼虫肠道细菌多样性丰富.相关的种类和丰度信息为后期研究揭示肠道细菌介导泽兰实蝇寄主植物专化性奠定了基础.

  17. A phylogenetic study on galactose-containing Candida species based on 18S ribosomal DNA sequences.

    Science.gov (United States)

    Suzuki, Motofumi; Suh, Sung-Oui; Sugita, Takashi; Nakase, Takashi

    1999-10-01

    Phylogenetic relationships of 33 Candida species containing galactose in the cells were investigated by using 18S ribosomal DNA sequence analysis. Galactose-containing Candida species and galactose-containing species from nine ascomycetous genera were a heterogeneous assemblage. They were divided into three clusters (II, III, and IV) which were phylogenetically distant from cluster I, comprising 9 galactose-lacking Candida species, C. glabrata, C. holmii, C. krusei, C. tropicalis (the type species of Candida), C. albicans, C. viswanathii, C. maltosa, C. parapsilosis, C. guilliermondii, and C. lusitaniae, and 17 related ascomycetous yeasts. These three clusters were also phylogenetically distant from Schizosaccharomyces pombe, which contains galactomannan in its cell wall. Cluster II comprised C. magnoliae, C. vaccinii, C. apis, C. gropengiesseri, C. etchellsii, C. floricola, C. lactiscondensi, Wickerhamiella domercqiae, C. versatilis, C. azyma, C. vanderwaltii, C. pararugosa, C. sorbophila, C. spandovensis, C. galacta, C. ingens, C. incommunis, Yarrowia lipolytica, Galactomyces geotrichum, and Dipodascus albidus. Cluster III comprised C. tepae, C. antillancae and its synonym C. bondarzewiae, C. ancudensis, C. petrohuensis, C. santjacobensis, C. ciferrii (anamorph of Stephanoascus ciferrii), Arxula terrestris, C. castrensis, C. valdiviana, C. paludigena, C. blankii, C. salmanticensis, C. auringiensis, C. bertae, and its synonym C. bertae var. chiloensis, C. edax (anamorph of Stephanoascus smithiae), Arxula adeninivorans, and C. steatolytica (synonym of Zygoascus hellenicus). Cluster IV comprised C. cantarellii, C. vinaria, Dipodascopsis uninucleata, and Lipomyces lipofer. Two galactose-lacking and Q-8-forming species, C. stellata and Pichia pastoris, and 5 galactose-lacking and Q-9-forming species, C. apicola, C. bombi, C. bombicola, C. geochares, and C. insectalens, were included in Cluster II. Two galactose-lacking and Q-9-forming species, C. drimydis and C

  18. Cytogenetic characterization of olive flounder Paralichthys olivaceus: DNA content, karyotype, AgNORs and location of major ribosomal genes

    Institute of Scientific and Technical Information of China (English)

    WANG Xubo; ZHANG Quanqi; CHEN Yanjie; QI Jie; WANG Zhigang; WANG Xinglian

    2009-01-01

    A cytogenetic analysis of Paralichthys olivaceus was carried out using the flow cytometry method for DNA content, silver staining for the nucleolus organizer region (AgNORs) identification and one-color fluorescence in situ hybridization (FISH) for chromosomal mapping of major ribosomal genes. Nuclear DNA content was estimated by flow cytometry method using Gallus domesticus erythrocytes as the internal reference standard. The C-value of this species was (0.737±0.024) pg, and the DNA contents of each chromosome were estimated to be 16.51 Mb to 39.50 Mb after paired according to the average relative length. The FISH probe was made by PCR amplification of a DNA fragment containing internal transcribed spacers ITS1 between 18S and 5.8S ribosomal RNA gene, and labeled by PCR incorporation of bio-16-dUTP. FISH signals and AgNORs were both located on the secondary constrictions of chromosome 1. These results will provide a better understanding of the cytogenetic information of this species and would help for further research of the karyotype evolution in the order Pleuronectiformes.

  19. Detection and identification of the Candida species by 25S ribosomal DNA analysis in the urine of candidal cystitis.

    Science.gov (United States)

    Kano, Rui; Hattori, Yousuke; Okuzumi, Katsuko; Miyazaki, Yoshio; Yamauchi, Rie; Koie, Hiroshi; Watari, Toshihiro; Hasegawa, Atsuhiko

    2002-02-01

    Candida species in clinical urine samples were identified directly by the newly developed method of PCR analysis on 25S ribosomal DNA (rDNA). Two dogs were referred to the Animal Medical Center, Nihon University School of Veterinary Medicine, Fujisawa, Kanagawa, Japan for the examination of chronic cystitis. Microscopic examination of urine samples from these dogs revealed yeast cells. Urine culture on Sabouraud's dextrose agar at 27 degrees C for 5 days produced white to cream colored colonies. The isolates were identifical to Candida albicans and C. parapsilosis by mycological examination, respectively. The nucleotide sequences of 25S ribosomal DNA from these urine isolates showed 99% similarity to those of a reference strain of Candida albicans or C. parapsilosis. The nucleotide sequences of 25S rDNA obtained directly from urine samples were also identical to C. albicans and C. parapsilosis, respectively. Confirming the results on the isolates cultured from the same urine samples. This PCR analysis method could be available for the direct identification of Candida species in urine samples within 2 days.

  20. 基于16S rDNA序列的中国沿海短蛸种群遗传结构%Population genetic structure of Octopus ocellatus in coastal waters of China based on 16S rDNA sequence

    Institute of Scientific and Technical Information of China (English)

    吕振明; 李焕; 吴常文; 樊甄姣; 张建设

    2011-01-01

    采用线粒体基因测序技术,对中国沿海7个短蛸(Octopus ocellatus)群体的遗传结构和变异进行分析,以探讨种群扩散潜力对遗传结构的影响.共测定了100个短蛸样本的.485 bp的16s rDNA序列,经UPGMA聚类分析表明,中国沿海的短蛸群体存在着明显的种群结构.7个群体明显地分化为两大类群:一个类群由北方沿海的大连、烟台、青岛、连云港群体组成,另一个类群南南方沿海的上海、舟山和广东群体组成;两类群间存在14个同定核苷酸碱基的替换.两类群间的遗传分化系数FST和基因流Nm分别达0.878和0.069,并达到显著分化水平(P<0.05).AMOVA检验表明,两类群间的差异有87.76%存在于群体间,而仅有12.24%存在于群体内.两类群间的净遗传距离为0.019,表明可能为中度的种内群体间分化水平.依据分子钟理论推断,两类群的分化时间约为晚更新世冰期.两类群的分化可能与短蛸缺乏浮游幼体生活史和无长距离迁移习性有关,基因流与地理距离间的相关性符合脚踏石模型,进一步证实了这一点.同时短蛸群体的这种分化格局还可能与晚更新世以来中国沿海海平面的反复升降和长江口淡水的阻隔有关.%Genetic structure of populations is greatly influenced by the dispersal ability of marine organisms. It seems intuitive that limited dispersal capability should result in greater genetic differentiation. Octopus ocellatus is a typical cephalopod species which shows limited dispersal potential. In this study, the effect of dispersal capability on population genetic structure was tested on seven populations of O. ocellatus in coastal waters of China,by applying mitochondrial gene sequencing technology. A 485 bp segment of the 16S rDNA gene was sequenced and analyzed in 100 specimens. Results showed that strong genetic structure existed in seven O. ocellatus populations. Two distinct clades with 14 fixed nucleotide base variation

  1. 安徽铜陵尾矿堆中三价砷抗性菌株的分离、鉴定及16S rDNA分析%Isolation, identification and 16S rDNA sequences analysis of arsenic-resisting bacteria from mine tailing dumps of Tongling in Anhui Province

    Institute of Scientific and Technical Information of China (English)

    赵兴青; 李成祥; 王汝成; 陆现彩; 陆建军; 胡欢

    2009-01-01

    Three bacteria strains resistant to arsenic(Ⅲ), named WK-21, WK-31 and WK-32, were enriched with 2×10~3 mol/L NaAsO_2 and isolated on plates from the three pieces of rock (or soil) samples from Yangshanchong mine tailing dumps of Tonglin in Anhui Province. These strains are all aerobiotic and have a high resistance to arsenic(Ⅲ), and are respectively resistant to the most arsenic(Ⅲ) of 32, 56 and 50 mmol/L after being cultivated for 48 hours on the solid LB medium. Through a study of their growth in different concentrations of arsenic(Ⅲ), the authors found that the arsenic of low concentration made a small impact on or even slightly promoted the bacteria's growth and that, when the concentration of arsenic(Ⅲ) increased, the suppression of the growth was clearly enhanced. Based on a careful observation of the three strains' morphological characteristics, physiological and biochemical characteristics and 16S rDNA sequences, the authors identified the three strains as Arthrobacter sp., Rhodococcus equi and Paeni-bacillus sp., respectively. Since these arsenic-resisting strains were isolated from the soil samples of mine tailing dumps, the data obtained are likely to provide valuable materials for further studies of the environmental microbial remediation in the same kind of areas polluted by heavy metals and the mechanism for microbial resistance to heavy metals.%从安徽铜陵杨山冲尾矿库采集表层尾矿样品,通过砷富集培养,从3份样品中筛选得到3株具有较强As(Ⅲ) 抗性的细菌 WK-21、WK-31 和 WK-32,用不同 NaAsO2 浓度的 LB 培养基对菌株进行砷抗性检测,结果这3株菌分别能耐受32、56和50 mmol/L的As(Ⅲ),具有较高的耐砷性.对这3株菌进行不同梯度浓度 As(Ⅲ) 环境中的生长规律研究,结果表明砷在低浓度时对细菌生长有轻微促进作用或者几乎没影响,但随着砷浓度增大,抑制作用明显增强.根据对这3株菌进行形态观

  2. Microbial diversity in Diaphorina citri( Homoptera: Psyllidae) estimated by 16S rDNA analysis using DGGE and RFLP%基于16S rDNA序列的柑桔木虱体内共生菌多样性研究

    Institute of Scientific and Technical Information of China (English)

    殷幼平; 刘婷婷; 田圣超; 胡修峰; 吴东; 王中康

    2011-01-01

    昆虫消化道内是一个复杂的微生态系统,有大量的微生物存在.这些微生物对寄主发育、营养吸收和防御方面都起着重要的作用.本文利用基于16S rRNA基因的PCR-RFLP指纹图谱法和变性梯度凝胶电泳(denaturing gradient gel electrophoresis,DGGE)的方法对柑桔黄龙病虫-媒柑桔木虱Diaphorina citri体内细菌菌群多样性进行了研究.经PCR-RFLP分析显示31条序列与变形菌门的假单胞菌科、肠杆菌科、黄单胞菌科、伯克氏菌科、立克次氏菌科和根瘤菌科细菌具有较高同源性.柑桔木虱内共生细菌的优势菌群依次为合胞体共生菌(syncytiumendosymbiont)(同源性99%,5条序列,分离频率31%)、Candidatus Carsonella ruddii和Mycetocyte内共生菌(同源性98%,5条序列,分离频率31%)以及亚洲韧皮杆菌(Candidatus Liberibacter asiaticus)和内共生菌Wolbachia.对柑桔木虱内生细菌16S rDNA V3区序列的PCR-DGGE分析,条带相似性的UPMAGA聚类分析表明,采自九里香Murraya paniculata的柑桔木虱内生细菌大多聚为一支,而来自柑桔的聚在另一支,说明寄主差异对柑桔木虱内生细菌菌群构成的影响大于地理位置的影响.将PCR-DGGE条带测序,序列经GenBank序列比对发现柑桔木虱内生细菌主要属于变形菌门假单胞菌科、立克次氏菌科、肠杆菌科、黄单胞菌科以及厚壁菌门链球菌科和芽孢杆菌科.合胞体共生菌(条带3-4)因其稳定存在于木虱体内且不随柑桔木虱寄主和地理位置的改变而变化,可能是柑桔木虱体内的优势共生菌;内共生细菌Wolbachia也在柑桔木虱内稳定存在,表明我国柑桔木虱感染Wolbachia是普遍现象.PCR-RFLP和PCR-DGGE两种方法相结合较好地反映了柑桔木虱内生细菌菌群的多样性,而且均显示出柑桔木虱内的合胞体共生菌是主要的优势菌群.

  3. Purification of Drosophila ribosomal proteins. Isolation of proteins S8, S13, S14, S16, S19, S20/L24, S22/L26, S24, S25/S27, S26, S29, L4, L10/L11, L12, L13, L16, L18, L19, L27, 1, 7/8, 9, and 11.

    Science.gov (United States)

    Chooi, W Y

    1980-07-22

    The proteins of Drosophila melanogaster embryonic ribosomes were separated into seven groups (A80 through G80) by stepwise elution from carboxymethylcellulose with lithium chloride at pH 6.5 by procedures previously described [Chooi, W. Y., Sabatini, L. M., MacKlin, M. D., & Fraser, W. (1980) Biochemistry 19, 1425-1433]. Three relatively acidic proteins, S14, S25/S27, and 7/8, have now been isolated from group A80 by ion-exchange chromatog raphy on carboxymethylcellulose eluted with a linear gradient of lithium chloride at pH 4.2. Fractions containing the relatively basic proteins (groups B80 through G80) were furher combined into a total of 24 "pools". The criterion for combination was the migration patterns in one-dimensional polyacrylamide gels containing sodium dodecyl sulfate (NaDodS04) of every fifth fraction from the carboxymethylcellulose column. Each pool contained between 1 and 12 major proteins. Proteins S8, S13, S16, S19, S20/L24, S22/L26, S24, S26, S29, L4, L10/L11, L12, L13, L16, L18, L19, L27, 1, 9, and 11 have now been isolated from selected pools by gel filtration through Sephadix G-100. The amount of each protein recovered from a starting amount of 1.8 g of total 80S proteins varied form 0.2 to 10.8 mg. Five proteins had no detectable contamination, and in each of the others the impurities were no greater than 9%. The amino acid composition of the individual purified proteins was determined. The molecular weights of the proteins were estimated by polyacrylamide gel electrophoresis in NaDodSO4.

  4. Phylogenetic Analysis of 16S rDNA Sequence and PCR - RFLP of Bacillus from Fumao - flavor Daqu%福矛高温大曲中芽孢杆菌16S rDNA-RFLP及系统发育分析

    Institute of Scientific and Technical Information of China (English)

    颜林春; 张守财; 马校卫; 汤二将; 黄祖新; 陈由强

    2012-01-01

    目的:从福建建瓯黄华山酿酒有限公司高温大曲中分离出89株芽孢杆菌,通过初步筛选鉴定并进行微生物多样性研究.方法:对其16S rDNA进行PCR - RFLP分析和系统发育研究.结果:初步筛选得到的18株芽孢杆菌被HhaⅠ和MspⅠ酶切聚类分为四大组.通过系统发育分析样品中有6株Bacillus subtilis,4株Bacillus cereus,2株Bacillus sonorensis,2株Bacillus licheniformis,以及Bacillus pumilus、Bacillus oleronius、Bacillus coagulans和Bacillus thuringiensis各1株.结论:研究显示该高温大曲中可培养芽孢杆菌具有微生物多样性.

  5. Preparation of Metagenome from Soil and Analysis on the Sequence of a Bacteria 16S rDNA by Culture-independant Method%土壤宏基因组的提取及基于免培养技术分析细菌16S rDNA

    Institute of Scientific and Technical Information of China (English)

    方光伟; 洪雪梅; 蔡丽希; 彭锟; 林毅

    2005-01-01

    采用CTAB-SDS-冻融法和玻璃粉吸附法提取土壤宏基因组(metagenome),经琼脂糖凝胶电泳后用回收试剂盒对其进行纯化.以细菌16S rDNA通用引物从宏基因组中扩增出V8和V9两个高变区,回收纯化后与克隆载体pMD18-T连接,转化大肠杆菌DH5α,随机挑取一个阳性克隆菌进行序列测定,经BLAST分析表明该序列所代表的是一个不动杆菌属(Acinetobacter)细菌.本研究结果为分析土壤微生物种群结构和直接从土壤中分离功能基因奠定了基础.

  6. Phylogeny of Ptychostomum (Bryaceae, Musci) inferred from sequences of nuclear ribosomal DNA internal transcribed spacer (ITS) and chloroplast rps4

    Institute of Scientific and Technical Information of China (English)

    Chen-Ying WANG; Jian-Cheng ZHAO

    2009-01-01

    The phylogeny of Ptychostomum was first undertaken based on analysis of the internal transcribed spacer (ITS) region of the nuclear ribosomal (nr) DNA and by combining data from nrDNA ITS and chloroplast DNA rps4 sequences. Maximum parsimony, maximum likelihood, and Bayesian analyses all support the conclu-sion that the reinstated genus Ptychostomum is not monophyletic. Ptychostomum funkii (Schwagr.) J. R. Spence (= Bryum funkii Schwagr.) is placed within a clade containing the type species of Bryum, B. argenteum Hedw. The remaining members of Ptychostomum investigated in the present study constitute another well-supported clade. The results are congruent with previous molecular analyses. On the basis of phylogenetic evidence, we agree with Bryum lonchocaulon Mull. Hal., Bryum pallescens Schleich. ex Schwagr., and Bryum pallens Sw. to Ptychostomum.

  7. cDNA sequence analysis of ribosomal protein S13 gene in Plutella xylostella (Lepidoptera: Plutellidae)

    Institute of Scientific and Technical Information of China (English)

    SHAO-LIWANG; CHENG-FASHENG; CHUAN-LINGQIAO; MIYATATADASHI

    2005-01-01

    Ribosomal protein S 13 gene has been cloned and analyzed in many organisms,but there are few documents relating to insects. In this communication, the full-length cDNA sequence of ribosomal protein S 13 gene in the diamondback moth, Plutella xylostella(Lepidoptera: Plutellidae), was determined by using PCR amplification technique. The features of the ribosomal protein S 13 gene sequence were analyzed and the deduced amino acids sequence was compared with those from other insects. The results of multi-alignment of the amino acid sequences between the diamondback moth and other insect species revealed that this gene sequence is highly conserved in insects. Based on maximum likelihood method, a phylogenetic tree was constructed from 10 different species using PHYLIP software. It showed that nematode is one separate lineage and the five insect speciesbe long to another lineage, whereas those species higher than insects form the third one. The pattern of this phylogenetic tree evidently represented the evolution of different species.

  8. Genetic differentiation of strongyloides stercoralis from two different climate zones revealed by 18S ribosomal DNA sequence comparison.

    Science.gov (United States)

    Pakdee, Wallop; Thaenkham, Urusa; Dekumyoy, Paron; Sa-Nguankiat, Surapol; Maipanich, Wanna; Pubampen, Somchit

    2012-11-01

    Over 70 countries in tropical and subtropical zones are endemic areas for Strongyloides stercoralis, with a higher prevalence of the parasite often occurring in tropical regions compared to subtropical ones. In order to explore genetic variations of S. stercoralis form different climate zones, 18S ribosomal DNA of parasite specimens obtained from Thailand were sequenced and compared with those from Japan. The maximum likelihood indicates that S. stercoralis populations from these two different climate zones have genetically diverged. The genetic relationship between S. stercoralis populations is not related to the host species, but rather to moisture and temperature. These factors may directly drive genetic differentiation among isolated populations of S. stercoralis.

  9. Diversification in insular plants: Inferring the phylogenetic relationship in Aeonium (Crassulaceae) using ITS sequences of nuclear ribosomal DNA

    DEFF Research Database (Denmark)

    Jorgensen, T.H.; Frydenberg, J.

    1999-01-01

    importance of reticulate evolution in the genus. Based on the geographic distribution of this particular island group and the growth forms of its species, dispersal across similar ecological zones of different islands followed by adaptive radiation and isolation are suggested to be the prominent routes......The ITS regions of nuclear ribosomal DNA were sequenced in 37 species of the genus Aeonium. A phylogeny obtained through the use of parsimony agrees to some extent with the sectional division of the genus and confirms the position of two newly described species. It also suggests the potential...

  10. 16S rRNA in identification and typing of Clostridium botulinum%16S rRNA在肉毒梭菌分型鉴定中的应用

    Institute of Scientific and Technical Information of China (English)

    卢卫嘉; 毛晓燕; 熊颖; 张超; 王建锋

    2011-01-01

    Objective To establish a rapid, reliable method for identifying and typing of Clostridium botulinum using 16S rDNA sequencing and phylogenetic tree construction. Methods Clostridium genome templates were extracted from 9 strains, including LCL063, 830110, LC175, LCL155, 66418, N153, 61082, ALASKA, and IWANAIs 16S rRNA genes were amplifed by PCR with the 16S rRNA specific primers, and then the PCR products were cloned to pGEM -T Easy vector and sequenced. Finally, the sequence of 16S rDNA was analyzed by Clustal and Mega program; the phylogenetic trees were constructed by Neighor joining and Maximum parsimony. Results It was found that LCL063, 830110, and LCL175 were BONT/E producing Clostridium butyricums; IWANAI and ALASKA were Clostridium botulinum type E. The results of the present method were consistent with those of the conventional method. Conclusion 16S rRNA sequencing combined with phylogenetic tree analysis is a rapid and accurate method in Clostridium botulinum identification, and the method may serve as a criterion for bacterial typing with the completion of ribosomal RNA data bank.%目的 建立一种快速、可靠的对肉毒梭菌进行分型鉴定的手段.方法 以从LCL063、830110、LC175、LCL155、66418、N153、61082、ALASKA、IWANAI共9株梭菌中提取的基因组DNA为模板,利用16S rRNA特异性引物分别进行PCR扩增并进行T-A克隆转化、测序.通过Clustal和Mega软件分析16S rDNA序列,以NJ法和MP法构建进化树,分析其种属特异性.结果 16S rRNA分型结果可判断出LCL063、830110、LCL175为产E型毒素的酪酸梭菌.IWANAI与ALASKA株为E型肉毒梭菌.与传统分型鉴定得到的结果一致.结论 16S rRNA在肉毒梭菌分型鉴定中具有快速、准确的优势,随着核糖体库的不断完善,有望成为细菌分型鉴定的标准依据.

  11. The Identification of Discriminating Patterns from 16S rRNA Gene to Generate Signature for Bacillus Genus.

    Science.gov (United States)

    More, Ravi P; Purohit, Hemant J

    2016-08-01

    The 16S ribosomal RNA (16S rRNA) gene has been widely used for the taxonomic classification of bacteria. A molecular signature is a set of nucleotide patterns, which constitute a regular expression that is specific to each particular taxon. Our main goal was to identify discriminating nucleotide patterns in 16S rRNA gene and then to generate signatures for taxonomic classification. To demonstrate our approach, we used the phylum Firmicutes as a model using representative taxa Bacilli (class), Bacillales (order), Bacillaceae (family), and Bacillus (genus), according to their dominance at each hierarchical taxonomic level. We applied combined composite vector and multiple sequence alignment approaches to generate gene-specific signatures. Further, we mapped all the patterns into the different hypervariable regions of 16S rRNA gene and confirmed the most appropriate distinguishing region as V3-V4 for targeted taxa. We also examined the evolution in discriminating patterns of signatures across taxonomic levels. We assessed the comparative classification accuracy of signatures with other methods (i.e., RDP Classifier, KNN, and SINA). Results revealed that the signatures for taxa Bacilli, Bacillales, Bacillaceae, and Bacillus could correctly classify isolate sequences with sensitivity of 0.99, 0.97, 0.94, and 0.89, respectively, and specificity close to 0.99. We developed signature-based software DNA Barcode Identification (DNA BarID) for taxonomic classification that is available at website http://www.neeri.res.in/DNA_BarID.htm . This pattern-based study provides a deeper understanding of taxon-specific discriminating patterns in 16S rRNA gene with respect to taxonomic classification. PMID:27104769

  12. The Identification of Discriminating Patterns from 16S rRNA Gene to Generate Signature for Bacillus Genus.

    Science.gov (United States)

    More, Ravi P; Purohit, Hemant J

    2016-08-01

    The 16S ribosomal RNA (16S rRNA) gene has been widely used for the taxonomic classification of bacteria. A molecular signature is a set of nucleotide patterns, which constitute a regular expression that is specific to each particular taxon. Our main goal was to identify discriminating nucleotide patterns in 16S rRNA gene and then to generate signatures for taxonomic classification. To demonstrate our approach, we used the phylum Firmicutes as a model using representative taxa Bacilli (class), Bacillales (order), Bacillaceae (family), and Bacillus (genus), according to their dominance at each hierarchical taxonomic level. We applied combined composite vector and multiple sequence alignment approaches to generate gene-specific signatures. Further, we mapped all the patterns into the different hypervariable regions of 16S rRNA gene and confirmed the most appropriate distinguishing region as V3-V4 for targeted taxa. We also examined the evolution in discriminating patterns of signatures across taxonomic levels. We assessed the comparative classification accuracy of signatures with other methods (i.e., RDP Classifier, KNN, and SINA). Results revealed that the signatures for taxa Bacilli, Bacillales, Bacillaceae, and Bacillus could correctly classify isolate sequences with sensitivity of 0.99, 0.97, 0.94, and 0.89, respectively, and specificity close to 0.99. We developed signature-based software DNA Barcode Identification (DNA BarID) for taxonomic classification that is available at website http://www.neeri.res.in/DNA_BarID.htm . This pattern-based study provides a deeper understanding of taxon-specific discriminating patterns in 16S rRNA gene with respect to taxonomic classification.

  13. Virtual Ribosome - a comprehensive DNA translation tool with support for integration of sequence feature annotation

    DEFF Research Database (Denmark)

    Wernersson, Rasmus

    2006-01-01

    of alternative start codons. ( ii) Integration of sequences feature annotation - in particular, native support for working with files containing intron/ exon structure annotation. The software is available for both download and online use at http://www.cbs.dtu.dk/services/VirtualRibosome/....

  14. Molecular phylogeny of Cricetulus griseus based on partial sequences of mitochondrial 16S rRNA gene analysis%中国地鼠线粒体DNA 16S rRNA基因序列分析及分子系统发育研究

    Institute of Scientific and Technical Information of China (English)

    宋国华; 高继萍; 王裕; 王春芳; 刘田福

    2013-01-01

    目的 通过克隆分析中国地鼠16S基因的部分序列,对中国地鼠16S基因的结构和功能进行初步探索和揭示.方法 从GenBank中已报道的啮齿动物16S基因保守区设计一对引物,进行PCR扩增,测序.用Blastn与GenBank中七种啮齿类动物的16S基因进行序列比较,分析其碱基组成及变异情况,并用邻接法(NJ)、非加权组平均法(UPGMA)构建分子系统树,在分子水平上探讨中国地鼠和其他啮齿类动物的进化关系,对中国地鼠的种属地位进行了进一步验证.结果 获得了中国地鼠线粒体16S基因的部分序列,其碱基组成A、T、C、G分别为40.5%、24.5%、18.7%、16.3%,与其他七种啮齿类动物的碱基含量相比,各碱基含量基本相似.NJ进化树表明,中国地鼠、金黄地鼠与欧洲仓鼠先聚为一支,小鼠与大鼠先聚为一支,东方田鼠、台湾田鼠与东欧田鼠先聚为一支.结论 中国地鼠和金黄地鼠的亲缘关系最近,与传统的分类地位基本吻合.%Objective To observe the structure and function of 16S gene by cloning and analyzing the partial sequence of Cricetulus griseus 16S, and to explore its molecular phylogeny. Methods According to the conservative domain of the published sequence of 16S gene of rodent animals in GenBank, a pair of primers that could amplify Cricetulus griseus 16S gene was designed and synthesized. The sequence was compared with the published 16S genes in GenBank by Blastn. Based on the 16S rRNA sequences the molecular phylogenetic trees were constructed by neighbor-joining method, unweighted air-group method with arithmetic means, and the taxonomic status of Cricetulus griseus was estimated at molecular level. Results A part of sequences of 16S rRNA gene in Cricetulus griseus was obtained,and the A, T, C, G base average contents were 40. 5% ,24. 5% ,18. 7% and 16. 3% , respectively. The 16S base content was similar to that in other 6 rodent species. The neighbor-joining ( NJ

  15. The IGS-ETS in Bacillus (Insecta Phasmida: molecular characterization and the relevance of sex in ribosomal DNA evolution

    Directory of Open Access Journals (Sweden)

    Passamonti Marco

    2008-10-01

    Full Text Available Abstract Background DNA encoding for ribosomal RNA (rDNA is arranged in tandemly-repeated subunits, each containing ribosomal genes and non-coding spacers. Because tandemly-repeated, rDNA evolves under a balanced influence of selection and "concerted evolution", which homogenizes rDNA variants over the genome (through genomic turnover mechanisms and the population (through sexuality. Results In this paper we analyzed the IGS-ETS of the automictic parthenogen Bacillus atticus and the bisexual B. grandii, two closely related stick-insect species. Both species share the same IGS-ETS structure and sequence, including a peculiar head-to-tail array of putative transcription enhancers, here named Bag530. Sequence variability of both IGS-ETS and Bag530 evidenced a neat geographic and subspecific clustering in B. grandii, while B. atticus shows a little but evident geographic structure. This was an unexpected result, since the parthenogen B. atticus should lack sequence fixation through sexuality. In B. atticus a new variant might spread in a given geographic area through colonization by an all-female clone, but we cannot discard the hypothesis that B. atticus was actually a bisexual taxon in that area at the time the new variant appeared. Moreover, a gene conversion event between two Bag530 variants of B. grandii benazzii and B. grandii maretimi suggested that rRNA might evolve according to the so-called "library hypothesis" model, through differential amplification of rDNA variants in different taxa. Conclusion On the whole, Bacillus rDNA evolution appears to be under a complex array of interacting mechanisms: homogenization may be achieved through genomic turnover that stabilizes DNA-binding protein interactions but, simultaneously, new sequence variants can be adopted, either by direct appearance of newly mutated repeats, or by competition among repeats, so that both DNA-binding proteins and repeat variants drive each other's evolution. All this

  16. A ribosomal protein gene cluster is encoded in the mitochondrial DNA of Dictyostelium discoideum: UGA termination codons and similarity of gene order to Acanthamoeba castellanii.

    Science.gov (United States)

    Iwamoto, M; Pi, M; Kurihara, M; Morio, T; Tanaka, Y

    1998-04-01

    We sequenced a region of about 14.5 kb downstream from the ribosomal protein L11 gene (rpl11) in the mitochondrial DNA (54+/-2 kb) of the cellular slime mold Dictyostelium discoideum. Sequence analysis revealed that eleven ribosomal protein genes and six open reading frames (ORFs) formed a cluster arranged in the order: rpl11-orf189-rps12-rps7-rpl2-rps19-+ ++orf425-orf1740-rpl16-rpl14-orf188- rps14-rps8-rpl6-rps13-orf127-orf796. This order was very similar to that of homologous genes in Acanthamoeba castellanii mitochondrial DNA. The N-terminal region of ORF425 and the C-terminal region of ORF1740 had partial similarities to the S3 ribosomal protein of other organisms. The termination codons of rpl16 and orf188 were UGA, which has not hitherto been found in genes encoded in D. discoideum mitochondrial DNA. PMID:9560439

  17. 应用rpoB和16S rDNA基因的变性梯度凝胶电泳技术对山羊瘤胃细菌多样性的研究%Use of rpo B and 16S rDNA genes to analyze rumen bacterial diversity of goat using PCR and DGGE

    Institute of Scientific and Technical Information of China (English)

    石鹏君; 柏映国; 袁铁铮; 姚斌; 范云六

    2007-01-01

    采用免培养的rpoB和16S rDNA基因的变性梯度凝胶电泳技术(DGGE)对3种山羊(波尔山羊,内蒙古绒山羊,四川南江黄羊)瘤胃细菌优势菌群结构进行了比较分析.研究结果显示 rpo B DGGE图谱中条带数目少于16S rDNA图谱,并且条带分离效果明显,更有利于分析瘤胃细菌群落组成.从两种DGGE图谱中均可以发现3种山羊瘤胃细菌具有一定的相似性,种内个体间相似性明显高于种间相似性,这说明寄主品种是影响瘤胃细菌种群构成的一个重要因素.同时进行了部分优势细菌16S rDNA基因V6-V8区序列的系统发育分析.基因序列分析表明,DGGE图谱中优势条带的16S rDNA基因序列中有4条克隆的序列与基因库最相似菌的相似性大于97%,余下的克隆序列相似性在89%~96%之间,其中13条序列的与之相似性最高的序列均来自于未被鉴定的瘤胃细菌.

  18. Close sequence identity between ribosomal DNA episomes of the non-pathogenic Entamoeba dispar and pathogenic Entamoeba histolytica

    Indian Academy of Sciences (India)

    Jaishree Paul; Alok Bhattacharya; Sudha Bhattacharya

    2002-11-01

    Entamoeba dispar and Entamoeba histolytica are now recognized as two distinct species – the former being nonpathogenic to humans. We had earlier studied the organization of ribosomal RNA genes in E. histolytica. Here we report the analysis of ribosomal RNA genes in E. dispar. The rRNA genes of E. dispar, like their counterpart in E. histolytica are located on a circular rDNA molecule. From restriction map analysis, the size of E. dispar rDNA circle was estimated to be 24.4 kb. The size was also confirmed by linearizing the circle with BsaHI, and by limited DNAseI digestion. The restriction map of the E. dispar rDNA circle showed close similarity to EhR1, the rDNA circle of E. histolytica strain HM-1:IMSS which has two rDNA units per circle. The various families of short tandem repeats found in the upstream and downstream intergenic spacers (IGS) of EhR1 were also present in E. dispar. Partial sequencing of the cloned fragments of E. dispar rDNA and comparison with EhR1 revealed only 2.6% to 3.8% sequence divergence in the IGS. The region Tr and the adjoining PvuI repeats in the IGS of EhR1, which are missing in those E. histolytica strains that have one rDNA unit per circle, were present in the E. dispar rDNA circle. Such close similarity in the overall organization and sequence of the IGS of rDNAs of two different species is uncommon. In fact the spacer sequences were only slightly more divergent than the 18S rRNA gene sequence which differs by 1.6% in the two species. The most divergent sequence between E. histolytica and E. dispar was the internal transcribed spacer, ITS2. Therefore, it was concluded that probes derived from the ITS1 and ITS2 sequences would be more reliable and reproducible than probes from the IGS regions used earlier for identifying these species.

  19. Physical mapping of 5S and 18S ribosomal DNA in three species of Agave (Asparagales, Asparagaceae

    Directory of Open Access Journals (Sweden)

    Victor Manuel Gomez-Rodriguez

    2013-08-01

    Full Text Available Agave Linnaeus, 1753 is endemic of America and is considered one of the most important crops in Mexico due to its key role in the country’s economy. Cytogenetic analysis was carried out in A. tequilana Weber, 1902 ‘Azul’, A. cupreata Trelease et Berger, 1915 and A. angustifolia Haworth, 1812. The analysis showed that in all species the diploid chromosome number was 2n = 60, with bimodal karyotypes composed of five pairs of large chromosomes and 25 pairs of small chromosomes. Furthermore, different karyotypical formulae as well as a secondary constriction in a large chromosome pair were found in all species. Fluorescent in situ hybridization (FISH was used for physical mapping of 5S and 18S ribosomal DNA (rDNA. All species analyzed showed that 5S rDNA was located in both arms of a small chromosome pair, while 18S rDNA was associated with the secondary constriction of a large chromosome pair. Data of FISH analysis provides new information about the position and number of rDNA loci and helps for detection of hybrids in breeding programs as well as evolutionary studies.

  20. Systematics of Chaetognatha under the light of molecular data, using duplicated ribosomal 18S DNA sequences.

    Science.gov (United States)

    Papillon, Daniel; Perez, Yvan; Caubit, Xavier; Le Parco, Yannick

    2006-03-01

    While the phylogenetic position of Chaetognatha has became central to the question of early bilaterian evolution, the internal systematics of the phylum are still not clear. The phylogenetic relationships of the chaetognaths were investigated using newly obtained small subunit ribosomal RNA nuclear 18S (SSU rRNA) sequences from 16 species together with 3 sequences available in GenBank. As previously shown with the large subunit ribosomal RNA 28S gene, two classes of Chaetognatha SSU rRNA gene can be identified, suggesting a duplication of the whole ribosomal cluster; allowing the rooting of one class of genes by another in phylogenetic analyses. Maximum Parsimony, Maximum Likelihood and Bayesian analyses of the molecular data, and statistical tests showed (1) that there are three main monophyletic groups: Sagittidae/Krohnittidae, Spadellidae/Pterosagittidae, and Eukrohniidae/Heterokrohniidae, (2) that the group of Aphragmophora without Pterosagittidae (Sagittidae/Krohnittidae) is monophyletic, (3) the Spadellidae/Pterosagittidae and Eukrohniidae/Heterokrohniidae families are very likely clustered, (4) the Krohnittidae and Pterosagittidae groups should no longer be considered as families as they are included in other groups designated as families, (5) suborder Ctenodontina is not monophyletic and the Flabellodontina should no longer be considered as a suborder, and (6) the Syngonata/Chorismogonata and the Monophragmophora/Biphragmophora hypotheses are rejected. Such conclusions are considered in the light of morphological characters, several of which are shown to be prone to homoplasy. PMID:16434216

  1. Arrested development of the myxozoan parasite, Myxobolus cerebralis, in certain populations of mitochondrial 16S lineage III Tubifex tubifex

    Science.gov (United States)

    Baxa, D.V.; Kelley, G.O.; Mukkatira, K.S.; Beauchamp, K.A.; Rasmussen, C.; Hedrick, R.P.

    2008-01-01

    Laboratory populations of Tubifex tubifex from mitochondrial (mt)16S ribosomal DNA (rDNA) lineage III were generated from single cocoons of adult worms releasing the triactinomyxon stages (TAMs) of the myxozoan parasite, Myxobolus cerebralis. Subsequent worm populations from these cocoons, referred to as clonal lines, were tested for susceptibility to infection with the myxospore stages of M. cerebralis. Development and release of TAMs occurred in five clonal lines, while four clonal lines showed immature parasitic forms that were not expelled from the worm (non-TAM producers). Oligochaetes from TAM- and non-TAM-producing clonal lines were confirmed as lineage III based on mt16S rDNA and internal transcribed spacer region 1 (ITS1) sequences, but these genes did not differentiate these phenotypes. In contrast, random amplified polymorphic DNA analyses of genomic DNA demonstrated unique banding patterns that distinguished the phenotypes. Cohabitation of parasite-exposed TAM- and non-TAM-producing phenotypes showed an overall decrease in expected TAM production compared to the same exposure dose of the TAM-producing phenotype without cohabitation. These studies suggest that differences in susceptibility to parasite infection can occur in genetically similar T. tubifex populations, and their coexistence may affect overall M. cerebralis production, a factor that may influence the severity of whirling disease in wild trout populations. ?? 2007 Springer-Verlag.

  2. cDNA Cloning, Expression and Characterization of an Allergenic 60s Ribosomal Protein of Almond (Prunus dulcis

    Directory of Open Access Journals (Sweden)

    Abolhassani Mohsen

    2009-06-01

    Full Text Available Tree nuts, including almond (prunus dulcis are a source of food allergens often associated with life-threatening allergic reactions in susceptible individuals. Although the proteins in almonds have been biochemically characterized, relatively little has been reported regarding the identity of the allergens involved in almond sensitivity. The present study was undertaken to identify the allergens of the almond by cDNA library approach. cDNA library of almond seeds was constructed in Uni-Zap XR lamda vector and expressed in E. coli XL-1 blue. Plaques were immunoscreened with pooled sera of allergic patients. The cDNA clone reacting significantly with specific IgE antibodies was selected and subcloned and subsequently expressed in E. coli. The amino acids deducted from PCR product of clone showed homology to 60s acidic ribosomal protein of almond. The expressed protein was 11,450 Dalton without leader sequence. Immunoreactivity of the recombinant 60s ribosomal protein (r60sRP was evaluated with dot blot analysis using pooled and individual sera of allergic patients. The data showed that r60sRP and almond extract (as positive control possess the ability to bind the IgE antibodies. The results showed that expressed protein is an almond allergen.Whether this r60sRP represents a major allergen of almond needs to be further studied which requires a large number of sera from the almond atopic patients and also need to determine the IgE-reactive frequencies of each individual allergen.

  3. TALE nickase mediates high efficient targeted transgene integration at the human multi-copy ribosomal DNA locus.

    Science.gov (United States)

    Wu, Yong; Gao, Tieli; Wang, Xiaolin; Hu, Youjin; Hu, Xuyun; Hu, Zhiqing; Pang, Jialun; Li, Zhuo; Xue, Jinfeng; Feng, Mai; Wu, Lingqian; Liang, Desheng

    2014-03-28

    Although targeted gene addition could be stimulated strikingly by a DNA double strand break (DSB) created by either zinc finger nucleases (ZFNs) or TALE nucleases (TALENs), the DSBs are really mutagenic and toxic to human cells. As a compromised solution, DNA single-strand break (SSB) or nick has been reported to mediate high efficient gene addition but with marked reduction of random mutagenesis. We previously demonstrated effective targeted gene addition at the human multicopy ribosomal DNA (rDNA) locus, a genomic safe harbor for the transgene with therapeutic potential. To improve the transgene integration efficiency by using TALENs while lowering the cytotoxicity of DSBs, we created both TALENs and TALE nickases (TALENickases) targeting this multicopy locus. A targeting vector which could integrate a GFP cassette at the rDNA locus was constructed and co-transfected with TALENs or TALENickases. Although the fraction of GFP positive cells using TALENs was greater than that using TALENickases during the first few days after transfection, it reduced to a level less than that using TALENickases after continuous culture. Our findings showed that the TALENickases were more effective than their TALEN counterparts at the multi-copy rDNA locus, though earlier studies using ZFNs and ZFNickases targeting the single-copy loci showed the reverse. Besides, TALENickases mediated the targeted integration of a 5.4 kb fragment at a frequency of up to 0.62% in HT1080 cells after drug selection, suggesting their potential application in targeted gene modification not being limited at the rDNA locus.

  4. A nuclear ribosomal DNA pseudogene in triatomines opens a new research field of fundamental and applied implications in Chagas disease

    Directory of Open Access Journals (Sweden)

    María Angeles Zuriaga

    2015-05-01

    Full Text Available A pseudogene, designated as "ps(5.8S+ITS-2", paralogous to the 5.8S gene and internal transcribed spacer (ITS-2 of the nuclear ribosomal DNA (rDNA, has been recently found in many triatomine species distributed throughout North America, Central America and northern South America. Among characteristics used as criteria for pseudogene verification, secondary structures and free energy are highlighted, showing a lower fit between minimum free energy, partition function and centroid structures, although in given cases the fit only appeared to be slightly lower. The unique characteristics of "ps(5.8S+ITS-2" as a processed or retrotransposed pseudogenic unit of the ghost type are reviewed, with emphasis on its potential functionality compared to the functionality of genes and spacers of the normal rDNA operon. Besides the technical problem of the risk for erroneous sequence results, the usefulness of "ps(5.8S+ITS-2" for specimen classification, phylogenetic analyses and systematic/taxonomic studies should be highlighted, based on consistence and retention index values, which in pseudogenic sequence trees were higher than in functional sequence trees. Additionally, intraindividual, interpopulational and interspecific differences in pseudogene amount and the fact that it is a pseudogene in the nuclear rDNA suggests a potential relationships with fitness, behaviour and adaptability of triatomine vectors and consequently its potential utility in Chagas disease epidemiology and control.

  5. Establish and application of the high throughput sequencing method for soil microbial 16S rDNA using Ion Torrent PGM%土壤微生物16S rDNA的Ion Torrent PGM高通量检测方法构建与应用

    Institute of Scientific and Technical Information of China (English)

    毛伟华; 吴三玲; 张旭

    2015-01-01

    采用Ion Torrent Personal Genome Machine (PGM)测序平台,以16S rRNA基因V4-V5区为标靶,沼泽土壤和草坪土壤为材料,建立土壤微生物16S rDNA检测方法.结果表明,当测序序列数达到15 000条左右,两种土壤样品的Shannon曲线趋于平稳,而且沼泽土壤的多样性指数明显高于草坪土壤.在沼泽土壤和草坪土壤中分别检测到7 615和8 072个OTUs,分属于30门、53纲、93目、130科、182属和29门、52纲、88目、125科、183属.方差分析表明两类土壤存在着丰度差异显著的微生物类群和OTUs.根据样品间相似度分析,所有测试样本可明显分成两组,而且3个重复各自归为一组.可见,该试验所建立的Ion Torrent PGM土壤微生物16S rDNA检测法具有高通量、高灵敏度等优点,能够较为全面和准确的反映土壤微生物群落结构,从而可为土壤微生物群落结构研究提供强有力的检测工具.

  6. Rapid identification of veterinary-relevant Mycobacterium tuberculosis complex species using 16S rDNA, IS6110 and Regions of Difference-targeted dual-labelled hydrolysis probes.

    Science.gov (United States)

    Costa, Pedro; Amaro, Ana; Ferreira, Ana S; Machado, Diana; Albuquerque, Teresa; Couto, Isabel; Botelho, Ana; Viveiros, Miguel; Inácio, João

    2014-12-01

    Members of the Mycobacterium tuberculosis complex (MTC) are causative agents of tuberculosis (TB) in both humans and animals. MTC species are genetically very similar but may differ in their epidemiology, namely geographic distribution and host preferences, virulence traits and antimicrobial susceptibility patterns. However, the conventional laboratory diagnosis does not routinely differentiate between the species of the MTC. In this work we describe a rapid and robust two-step five-target probe-based real-time PCR identification algorithm, based on genomic deletion analysis, to identify the MTC species most commonly associated with TB in livestock and other animals. The first step allows the confirmation of the cultures as MTC members, by targeting their IS6110 element, or as a mycobacterial species, if only a 16S rDNA product is detected in the duplex amplification reaction. If a MTC member is identified, the second amplification step allows the assessment of the presence or absence of the RD1, RD4 and RD9 genomic regions. The correspondent pattern allows us to infer the species of the isolate as M. tuberculosis (if all RDs are present), Mycobacterium caprae (if only RD1 and RD4 are present) and Mycobacterium bovis (if only RD1 is present). The identification algorithm developed presented an almost perfect agreement with the results of the routine bacteriological analysis, with a kappa coefficient of 0.970 (CI(P95%) 0.929-1.000). The assay is able to be adaptable to automation and implementation in the routine diagnostic framework of veterinary diagnostic laboratories, with a particular focus for reference laboratories.

  7. 菌株F12-11-1-2的16S rDNA序列分析及其生理生化性质研究%The 16S rDNA Sequence Analysis and Phenotypical Study of Strain F12-11-1-2

    Institute of Scientific and Technical Information of China (English)

    刘小宇; 许强芝; 杨妤; 艾峰; 焦炳华

    2007-01-01

    菌株F12-11-1-2是一株从中国东海浙江海域200m的海泥中分离得到的,具有抗稻瘟霉(Pyricularia oryzae)活性.通过对菌株的形态、培养特征、生理生化特征的研究以及16S rDNA序列分析,结果表明它是一株适应了海洋环境的芽孢杆菌属(Bacillus)的枯草芽孢杆菌(Bacillus subtilis).

  8. Factors that affect large subunit ribosomal DNA amplicon sequencing studies of fungal communities: classification method, primer choice, and error.

    Directory of Open Access Journals (Sweden)

    Teresita M Porter

    Full Text Available Nuclear large subunit ribosomal DNA is widely used in fungal phylogenetics and to an increasing extent also amplicon-based environmental sequencing. The relatively short reads produced by next-generation sequencing, however, makes primer choice and sequence error important variables for obtaining accurate taxonomic classifications. In this simulation study we tested the performance of three classification methods: 1 a similarity-based method (BLAST + Metagenomic Analyzer, MEGAN; 2 a composition-based method (Ribosomal Database Project naïve bayesian classifier, NBC; and, 3 a phylogeny-based method (Statistical Assignment Package, SAP. We also tested the effects of sequence length, primer choice, and sequence error on classification accuracy and perceived community composition. Using a leave-one-out cross validation approach, results for classifications to the genus rank were as follows: BLAST + MEGAN had the lowest error rate and was particularly robust to sequence error; SAP accuracy was highest when long LSU query sequences were classified; and, NBC runs significantly faster than the other tested methods. All methods performed poorly with the shortest 50-100 bp sequences. Increasing simulated sequence error reduced classification accuracy. Community shifts were detected due to sequence error and primer selection even though there was no change in the underlying community composition. Short read datasets from individual primers, as well as pooled datasets, appear to only approximate the true community composition. We hope this work informs investigators of some of the factors that affect the quality and interpretation of their environmental gene surveys.

  9. CELL CHEMICAL CHARACTERISTICS AND 16S rDNA SEQUENCE ANALYSIS OF A BLUE-PIGMENT-PRODUCING STRAIN%产蓝色素放线菌细胞化学组分及16S rDNA序列分析

    Institute of Scientific and Technical Information of China (English)

    崔恒林; 陆玲; 陈一楠; 常青; 戴传超

    2001-01-01

    对分离自南京土壤中的一株高产水溶性蓝色素的放线菌菌株Streptomyces sp.进行了细胞化学组分及16S rDNA序列分析.细胞化学组分分析结果表明待定菌株的细胞壁含LL-DAP及甘氨酸,全细胞水解物含葡萄糖及核糖,全细胞脂肪酸组分主要为14~17碳的脂肪酸,其中anteiso-15和iso-16为主要组分,应归入链霉菌属.基于16S rDNA序列的聚类结果表明所选菌株基本分成9个分支,能够产生可溶性蓝色素的菌株聚成其中两个分支,即以S.coelicolor为代表的分支和以S.cyaneus为代表的分支,待定菌株与Streptomyces in digocolor的相似性为99.4%,属于S.cyaneus分支.

  10. Establishment of the pathogen 16 s rDNA detection method in dog and monkey common-ly used animal for cancer research%肿瘤研究常用动物犬和猴病原菌16srDNA检测方法的建立

    Institute of Scientific and Technical Information of China (English)

    时伟红; 郑志红

    2015-01-01

    目的:建立肿瘤研究常用动物犬和猴病原菌的16s rDNA PCR检测方法。方法:提取犬病原菌布鲁杆菌、空肠弯曲杆菌、小肠结肠炎耶尔森菌和猴病原菌志贺氏菌DNA,经过通用引物扩增,PCR产物为病原菌16s rDNA全长,经纯化后直接测序。利用BLAST软件从GenBank数据库中搜索相关菌株的序列进行序列比对和同源性分析,确定病原菌的种属。结果:测序结果与数据库中搜索到的相关菌株的序列进行序列比对显示,4种病原菌测序分别与布鲁杆菌、空肠弯曲杆菌、小肠结肠炎耶尔森菌和志贺氏菌序列一致。结论:利用16s rDNA PCR方法可快速准确地检测肿瘤研究常用动物犬和猴病原菌,对保证肿瘤研究准确性有重要意义。%Objective:To establish the pathogen detection method in dog and monkey commonly used animal for cancer research. Methods:The DNA of Brucella spp,Campylobaceter jejuni,Yersinia enterocolitica and Shigella spp confirmed by conventional methods were extracted. The full length of 16s rDNA was amplified with a set of universal primers. The PCR products were purified and sequenced directly. The related sequences were obtained from the Gen-Bank database using BLAST search software and the species of the pathogen were identified according to the sequence analysis and homology comparison of the 16s rDNA sequences. Results:The 16s rDNA sequences of the four pathogen were 100% concordance with the known standard nueleotide sequences of Brucella spp,Campylobaceter jejuni, Yersinia enterocolitica and Shigella spp. Conclusion:The PCR method based on 16s rDNA was reliable and could i-dentify dog and monkey the pathogen rapidly and accuracy.

  11. Novel essential gene Involved in 16S rRNA processing in Escherichia coli.

    Science.gov (United States)

    Kurata, Tatsuaki; Nakanishi, Shinobu; Hashimoto, Masayuki; Taoka, Masato; Yamazaki, Yukiko; Isobe, Toshiaki; Kato, Jun-ichi

    2015-02-27

    Biogenesis of ribosomes is a complex process mediated by many factors. While its transcription proceeds, ribosomal RNA (rRNA) folds itself into a characteristic three-dimensional structure through interaction with ribosomal proteins, during which its ends are processed. Here, we show that the essential protein YqgF, a RuvC family protein with an RNase-H-like motif, is involved in the processing of pre-16S rRNA during ribosome maturation. Indeed, pre-16S rRNA accumulated in cells of a temperature-sensitive yqgF mutant (yqgF(ts)) cultured at a non-permissive temperature. In addition, purified YqgF was shown to process the 5' end of pre-16S rRNA within 70S ribosomes in vitro. Mass spectrometry analysis of the total proteins in the yqgF(ts) mutant cells showed that the expression of genes containing multiple Shine-Dalgarno-like sequences was observed to be lower than in wild type. These results are interpreted to indicate that YqgF is involved in a novel enzymic activity necessary for the processing of pre-16S rRNA, thereby affecting elongation of translation.

  12. Chloroplast ribosomes and protein synthesis.

    OpenAIRE

    Harris, E. H.; Boynton, J E; Gillham, N W

    1994-01-01

    Consistent with their postulated origin from endosymbiotic cyanobacteria, chloroplasts of plants and algae have ribosomes whose component RNAs and proteins are strikingly similar to those of eubacteria. Comparison of the secondary structures of 16S rRNAs of chloroplasts and bacteria has been particularly useful in identifying highly conserved regions likely to have essential functions. Comparative analysis of ribosomal protein sequences may likewise prove valuable in determining their roles i...

  13. Physiological characters and 16S rDNA sequence phylogenetic analysis of a pathogenic bacterium isolated from Spodoptera exigua Hünber%罹病甜菜夜蛾分离菌株的生理特征及16S rDNA系统发育分析

    Institute of Scientific and Technical Information of China (English)

    齐放军; 刘缨; 季志英

    2004-01-01

    从自然罹病死亡的甜菜夜蛾虫体中分离出甜菜夜蛾致病菌QL-1,对其30项生理特征分析结果表明,QL-1菌株与肠杆菌科(Enterobacteriaceae),沙雷氏菌属(Serratta)中的粘质沙雷氏菌(Serratia marcescens)的生理特征相符合.进一步用PCR扩增出QL-1的16S rDNA基因片段,测定其序列并进行系统发育分析,结果也表明,该菌株与Serratia marcescens处于同一进化树分支中,相似性达99.2%以上.

  14. Analysis of Rumen Bacterial Diversity of Goat by Denaturing Gradient Gel Electrophoresis and 16S rDNA Sequencing%应用变性梯度凝胶电泳和16S rDNA序列分析对山羊瘤胃细菌多样性的研究

    Institute of Scientific and Technical Information of China (English)

    姚文; 朱伟云; 韩正康; Antoon D L Akkermans; Barbara Williams; Seerp Tamminga

    2004-01-01

    以取自3头安装有永久性瘤胃瘘管的土种山羊的瘤胃内容物为材料,经过DNA抽提和PCR扩增,扩增产物利用变性梯度凝胶电泳技术(DGGE,一种DNA指纹技术)分析瘤胃细菌在两种日粮条件下的多样性.同时利用基因序列分析技术,分析了16个在DGGE胶上有匹配带的克隆的16S rDNA序列,并与现有的数据库进行了比较.结果表明,饲喂基础日粮时3头山羊瘤胃内容物的DGGE图谱有一定的相似性(43%~55%);饲料中添加大豆黄酮一定程度上影响了瘤胃细菌的组成,DGGE谱带变化程度分别为1号36%、2号46%、3号30%.基因序列分析表明,DGGE图谱中优势条带的16S rDNA基因序列中有5个基因序列与基因数据库登录的相关序列的相似性大于97%,8个基因序列的相似性在90%~96%,余下的低于90%.相似性大于97%的5个克隆中,只有1个被鉴定为Prevotellasp.,其余4个都属于未被鉴定的瘤胃细菌.

  15. From DNA to proteins via the ribosome: Structural insights into the workings of the translation machinery

    Directory of Open Access Journals (Sweden)

    Agirrezabala Xabier

    2010-04-01

    Full Text Available Abstract Understanding protein synthesis in bacteria and humans is important for understanding the origin of many human diseases and devising treatments for them. Over the past decade, the field of structural biology has made significant advances in the visualisation of the molecular machinery involved in protein synthesis. It is now possible to discern, at least in outline, the way that interlocking ribosomal components and factors adapt their conformations throughout this process. The determination of structures in various functional contexts, along with the application of kinetic and fluorescent resonance energy transfer approaches to the problem, has given researchers the frame of reference for what remains as the greatest challenge: the complete dynamic portrait of protein synthesis in the cell.

  16. 基于16S rDNA序列探讨中国剑角蝗科的单系性及其六属的系统发育关系%A phylogenetic analysis of six genera of Acrididae and monophyly of Acrididae in China using 16S rDNA sequences (Orthoptera, Acridoidea)

    Institute of Scientific and Technical Information of China (English)

    孙正莉; 蒋国芳; 霍光明; 刘殿锋

    2006-01-01

    In Xia's system, the family Acrididae has long been recognized as a natural, monophyletic group, which contain six subfamilies in China. However, there has been much dispute over its monophyly. To investigate its monophyly and phylogenetic relationships among six genera Carsula, Phlaeoba, Mongolotettix, Gelastorhinus, Acrida, and Gonista within this family, we sequenced 450 bp fragments of 16S rRNA gene sequences of 14 recognized species and downloaded the sequences of another grasshopper Acrida turrita and two Tetrigidae species from GenBank. Phylogenetic trees were reconstructed with maximum parsimony, neighbor-joining, and maximum likelihood using the Tetrigidae species as outgroup. The monophyly of Acrididae was not supported in all analyses. The phylogenetic trees did not agree with the Chinese traditional classifications, but they just agreed well with Kevan's, which is popular in western countries. This prompt that the Chinese system must be earnestly improved and consummated. However, monophyly of genus Acrida was strongly supported. Leptacrinae was closely related to the species of the Chinese Catantopidae, not to Acrididae. Although gene sequences obtained from Acrida rufipes and Acrida shanghaica were identical, we could not conclude that they are the same species [Acta Zoologica Sinica 52 (2): 302 - 308, 2006].%在中国学者夏凯龄的分类系统中,剑角蝗科Acrididae一直被看作是单系群,包含6个亚科.但是,近年来的研究对其单系性争议较大.为探讨其单系性和剑角蝗属等6属的系统发育关系,我们测定了剑角蝗科14种蝗虫的16S rRNA基因部分序列,并从GenBank中下载了1种蝗虫的同源序列.以蚱科的2个种作外群,用NJ、MP及ML法重建系统发生树.由三棵分子系统树中得出的系统发生关系与中国的分类系统差别较大,都不支持剑角蝗科是单系群,但与国外Kevan的系统相一致,提示我们国内的分类系统亟待修改和完善.长腹蝗亚科与

  17. Analysis of Bacterial Communities during Cellulose Degradation by 16SrDNA-PCR-DGGE%纤维素降解过程中微生物群落的16S rDNA-PCR-DGGE分析

    Institute of Scientific and Technical Information of China (English)

    赵晓会; 刘元金

    2015-01-01

    采用兼性厌氧法筛选出一高效降解纤维素的复合微生物菌群,提取不同培养时间条件下降解菌体系的总DNA,并以其为模板采用PCR-DGGE技术研究了在纤维素降解过程中微生物群落的组成,结果表明,随着培养时间的不同,微生物的群落结构表现出差异.%A highly effective complex microbial community in cellulose degradation was selected and obtained through afacultative anaerobic. The bacterial DNA was extracted under different cultivation time conditions, and the composition of microbial community in cellulose degradation was studied by PCR-DGGE technology based on the above module.The results showed that there were different structures of microbial community with changing cultivation time.

  18. 16S rDNA Gene Clone and Detection of Pantoea stewartii subsp.stewartii by Real-Time Fluorescent PCR%玉米细菌性枯萎病菌16S rDNA基因克隆及TaqMan 探针实时荧光PCR

    Institute of Scientific and Technical Information of China (English)

    漆艳香; 肖启明; 朱水芳

    2003-01-01

    为给农业和植物检疫部门提供一种特异性强、灵敏度高,可以快速、直接检测植物病原菌的方法,将玉米细菌性枯萎病菌16S rDNA基因克隆测序,根据该细菌与其他细菌菌株16S rDNA序列差异,设计出对玉米细菌性枯萎病菌具有稳定点突变的特异性探针,除泛菌属3个种和欧氏菌属3个种外,还对假单胞菌属1个种,黄单胞菌属1个种,棒形杆菌属1个种,短小杆菌属1个种以及5种植原体进行了实时荧光PCR检测.结果表明:只有玉米细菌性枯萎病菌产生荧光,其他细菌和植原体都没有荧光产生.检测的灵敏度为104 CFU/mL的菌悬浮液,相当于4个细菌细胞的基因,灵敏度高,也就是说,反应体系中只要有2个活细菌,实时荧光PCR就能检测到.相对灵敏度为107 CFU/mL,而且整个检测过程只需2 h,由于实验采用独特全封闭反应管及光电传导系统,不用凝胶电泳,降低了污染.

  19. Evolution of ribosomal DNA-derived satellite repeat in tomato genome

    Directory of Open Access Journals (Sweden)

    Hur Cheol-Goo

    2009-04-01

    Full Text Available Abstract Background Tandemly repeated DNA, also called as satellite DNA, is a common feature of eukaryotic genomes. Satellite repeats can expand and contract dramatically, which may cause genome size variation among genetically-related species. However, the origin and expansion mechanism are not clear yet and needed to be elucidated. Results FISH analysis revealed that the satellite repeat showing homology with intergenic spacer (IGS of rDNA present in the tomato genome. By comparing the sequences representing distinct stages in the divergence of rDNA repeat with those of canonical rDNA arrays, the molecular mechanism of the evolution of satellite repeat is described. Comprehensive sequence analysis and phylogenetic analysis demonstrated that a long terminal repeat retrotransposon was interrupted into each copy of the 18S rDNA and polymerized by recombination rather than transposition via an RNA intermediate. The repeat was expanded through doubling the number of IGS into the 25S rRNA gene, and also greatly increasing the copy number of type I subrepeat in the IGS of 25-18S rDNA by segmental duplication. Homogenization to a single type of subrepeat in the satellite repeat was achieved as the result of amplifying copy number of the type I subrepeat but eliminating neighboring sequences including the type II subrepeat and rRNA coding sequence from the array. FISH analysis revealed that the satellite repeats are commonly present in closely-related Solanum species, but vary in their distribution and abundance among species. Conclusion These results represent that the dynamic satellite repeats were originated from intergenic spacer of rDNA unit in the tomato genome. This result could serve as an example towards understanding the initiation and the expansion of the satellite repeats in complex eukaryotic genome.

  20. Chromosome breakages associated with 45S ribosomal DNA sequences in spotted snakehead fish Channa punctatus.

    Science.gov (United States)

    Singh, Mamta; Barman, Anindya Sundar

    2013-01-01

    It is well known that transcriptionally inactive rRNA genes are correlated with DNA hyper-methylation and histone hypo-methylation and there is clear evidence in humans that DNA and histone modification which alter chromatin structure are related to chromosome fragility. Very little is known about the biological cause of 45S rDNA fragility. In this report we characterized the chromosome breakage or gap associated with 45S rDNA in a fish species Channa punctatus. The rDNA mapping in C. punctatus, showed many chromosome breakages or gap formations, and all occurred exclusively in the 45S rDNA sites in anterior kidney cells. We observed that the number of chromosomes plus chromosome fragments was often more than the expected 32 in most cells. Total 67 % metaphase spread showed the expected or normal 32 chromosomes, while 33 % metaphase spread showed 33 and/or 34 chromosomes and/or chromosome fragments. The chromosome lesions observed in this study are very similar cytologically to that of fragile sites observed in human chromosomes. Possible causes for the spontaneous expression of fragile sites and their potential biological significance are also discussed in present report.

  1. Phylogenetic Relationships and Genetic Variation in Longidorus and Xiphinema Species (Nematoda: Longidoridae) Using ITS1 Sequences of Nuclear Ribosomal DNA.

    Science.gov (United States)

    Ye, Weimin; Szalanski, Allen L; Robbins, R T

    2004-03-01

    Genetic analyses using DNA sequences of nuclear ribosomal DNA ITS1 were conducted to determine the extent of genetic variation within and among Longidorus and Xiphinema species. DNA sequences were obtained from samples collected from Arkansas, California and Australia as well as 4 Xiphinema DNA sequences from GenBank. The sequences of the ITS1 region including the 3' end of the 18S rDNA gene and the 5' end of the 5.8S rDNA gene ranged from 1020 bp to 1244 bp for the 9 Longidorus species, and from 870 bp to 1354 bp for the 7 Xiphinema species. Nucleotide frequencies were: A = 25.5%, C = 21.0%, G = 26.4%, and T = 27.1%. Genetic variation between the two genera had a maximum divergence of 38.6% between X. chambersi and L. crassus. Genetic variation among Xiphinema species ranged from 3.8% between X. diversicaudatum and X. bakeri to 29.9% between X. chambersi and X. italiae. Within Longidorus, genetic variation ranged from 8.9% between L. crassus and L. grandis to 32.4% between L. fragilis and L. diadecturus. Intraspecific genetic variation in X. americanum sensu lato ranged from 0.3% to 1.9%, while genetic variation in L. diadecturus had 0.8% and L. biformis ranged from 0.6% to 10.9%. Identical sequences were obtained between the two populations of L. grandis, and between the two populations of X. bakeri. Phylogenetic analyses based on the ITS1 DNA sequence data were conducted on each genus separately using both maximum parsimony and maximum likelihood analysis. Among the Longidorus taxa, 4 subgroups are supported: L. grandis, L. crassus, and L. elongatus are in one cluster; L. biformis and L. paralongicaudatus are in a second cluster; L. fragilis and L. breviannulatus are in a third cluster; and L. diadecturus is in a fourth cluster. Among the Xiphinema taxa, 3 subgroups are supported: X. americanum with X. chambersi, X. bakeri with X. diversicaudatum, and X. italiae and X. vuittenezi forming a sister group with X. index. The relationships observed in this study

  2. PCR amplification and characterization of the intergenic spacer region of the ribosomal DNA in Pyrenophora graminea.

    Science.gov (United States)

    Pecchia, S; Mercatelli, E; Vannacci, G

    1998-09-01

    Successful amplification of the whole intergenic spacer region of the nuclear ribosomal repeat (IGS) in Pyrenophora graminea was obtained with a PCR-based assay. Single amplification products showed length differences. Depending on the length of the IGS-PCR product, ca. 3.8 or 4.4 kb, two groups of isolates could be identified. The RFLP patterns of isolates obtained with the 6-base cutting enzymes Apal, BglII, DraI, EcoRV, HindIII and SacI were similar within each group and different between the two groups. Restriction patterns of IGS-PCR products digested with the 4-base cutting enzyme AluI were polymorphic among isolates in spite of their IGS-PCR product length. In order to characterize the long and short IGS-PCR products the restriction map is shown. The long product shows an additional HindIII site and a BglII site that is lacking in the short product. However, the latter shows a SacI site that is not present in the long IGS-PCR product. Therefore, the described PCR-RFLP analysis of the IGS appears to be a useful tool to resolve genetic variation between P. graminea isolates. PMID:9741081

  3. Extensive length variation in the ribosomal DNA intergenic spacer of yellow perch (Perca flavescens).

    Science.gov (United States)

    Kakou, Bidénam; Angers, Bernard; Glémet, Hélène

    2016-03-01

    The intergenic spacer (IGS) is located between ribosomal RNA (rRNA) gene copies. Within the IGS, regulatory elements for rRNA gene transcription are found, as well as a varying number of other repetitive elements that are at the root of IGS length heterogeneity. This heterogeneity has been shown to have a functional significance through its effect on growth rate. Here, we present the structural organization of yellow perch (Perca flavescens) IGS based on its entire sequence, as well as the IGS length variation within a natural population. Yellow perch IGS structure has four discrete regions containing tandem repeat elements. For three of these regions, no specific length class was detected as allele size was seemingly normally distributed. However, for one repeat region, PCR amplification uncovered the presence of two distinctive IGS variants representing a length difference of 1116 bp. This repeat region was also devoid of any CpG sites despite a high GC content. Balanced selection may be holding the alleles in the population and would account for the high diversity of length variants observed for adjacent regions. Our study is an important precursor for further work aiming to assess the role of IGS length variation in influencing growth rate in fish. PMID:26841134

  4. Extensive polymorphism and chromosomal characteristics of ribosomal DNA in the characid fish Triportheus venezuelensis (Characiformes, Characidae

    Directory of Open Access Journals (Sweden)

    Mauro Nirchio

    2007-01-01

    Full Text Available The karyotype and chromosomal characteristics of the characid fish Triportheus venezuelensis were investigated using differential staining techniques (C-banding, Ag-NOR staining and fluorescent in situ hybridization (FISH with an 18S rDNA probe. The diploid chromosome number (2n = 52, karyotype composition and sex chromosome determination system of the ZZ/ZW type were the same as previously described in other species of the genus Triportheus. However, extensive variation regarding nucleolus organizer regions (NOR different from other species was observed. 18S rDNA sequences were distributed on nine chromosome pairs, but the number of chromosomes with Ag-NORs was usually lower, reaching a maximum of four chromosomes. When sequential staining experiments were performed, it was demonstrated that: 1. active NORs usually corresponded to segments with 18S rDNA genes identified in FISH experiments; 2. several 18S rDNA sequences were not silver-stained, suggesting that they do not correspond to active NORs; and 3. some chromosomes with silver-stained regions did not display any 18S rDNA signals. These findings characterize an extensive polymorphism associated with the NOR-bearing chromosomes of T. venezuelensis and emphasize the importance of combining traditional and molecular techniques in chromosome studies.

  5. Low variation in ribosomal DNA and internal transcribed spacers of the symbiotic fungi of leaf-cutting ants (Attini: Formicidae

    Directory of Open Access Journals (Sweden)

    Silva-Pinhati A.C.O.

    2004-01-01

    Full Text Available Leaf-cutting ants of the genera Atta and Acromyrmex (tribe Attini are symbiotic with basidiomycete fungi of the genus Leucoagaricus (tribe Leucocoprineae, which they cultivate on vegetable matter inside their nests. We determined the variation of the 28S, 18S, and 5.8S ribosomal DNA (rDNA gene loci and the rapidly evolving internal transcribed spacers 1 and 2 (ITS1 and ITS2 of 15 sympatric and allopatric fungi associated with colonies of 11 species of leafcutter ants living up to 2,600 km apart in Brazil. We found that the fungal rDNA and ITS sequences from different species of ants were identical (or nearly identical to each other, whereas 10 GenBank Leucoagaricus species showed higher ITS variation. Our findings suggest that Atta and Acromyrmex leafcutters living in geographic sites that are very distant from each other cultivate a single fungal species made up of closely related lineages of Leucoagaricus gongylophorus. We discuss the strikingly high similarity in the ITS1 and ITS2 regions of the Atta and Acromyrmex symbiotic L. gongylophorus studied by us, in contrast to the lower similarity displayed by their non-symbiotic counterparts. We suggest that the similarity of our L. gongylophorus isolates is an indication of the recent association of the fungus with these ants, and propose that both the intense lateral transmission of fungal material within leafcutter nests and the selection of more adapted fungal strains are involved in the homogenization of the symbiotic fungal stock.

  6. Affinities of Phylacia and the daldinoid Xylariaceae, inferred from chemotypes of cultures and ribosomal DNA sequences

    DEFF Research Database (Denmark)

    Bitzer, Jens; Laessøe, Thomas; Fournier, Jacques;

    2008-01-01

    . A comparison of their 5.8S/ITS nuc-rDNA sequences agreed in some important aspects with the above results: H. nicaraguense and H. polyporus appeared basal to a clade comprising Daldinia, Entonaema, and Ph. sagrana. The latter species appeared allied to D. caldariorum, but was distantly related to Pyrenomyxa...

  7. Revealing pancrustacean relationships: Phylogenetic analysis of ribosomal protein genes places Collembola (springtails in a monophyletic Hexapoda and reinforces the discrepancy between mitochondrial and nuclear DNA markers

    Directory of Open Access Journals (Sweden)

    Mariën J

    2008-03-01

    Full Text Available Abstract Background In recent years, several new hypotheses on phylogenetic relations among arthropods have been proposed on the basis of DNA sequences. One of the challenged hypotheses is the monophyly of hexapods. This discussion originated from analyses based on mitochondrial DNA datasets that, due to an unusual positioning of Collembola, suggested that the hexapod body plan evolved at least twice. Here, we re-evaluate the position of Collembola using ribosomal protein gene sequences. Results In total 48 ribosomal proteins were obtained for the collembolan Folsomia candida. These 48 sequences were aligned with sequence data on 35 other ecdysozoans. Each ribosomal protein gene was available for 25% to 86% of the taxa. However, the total sequence information was unequally distributed over the taxa and ranged between 4% and 100%. A concatenated dataset was constructed (5034 inferred amino acids in length, of which ~66% of the positions were filled. Phylogenetic tree reconstructions, using Maximum Likelihood, Maximum Parsimony, and Bayesian methods, resulted in a topology that supports monophyly of Hexapoda. Conclusion Although ribosomal proteins in general may not evolve independently, they once more appear highly valuable for phylogenetic reconstruction. Our analyses clearly suggest that Hexapoda is monophyletic. This underpins the inconsistency between nuclear and mitochondrial datasets when analyzing pancrustacean relationships. Caution is needed when applying mitochondrial markers in deep phylogeny.

  8. DNA Sequencing Diagnosis of Off-Season Spirochetemia with Low Bacterial Density in Borrelia burgdorferi and Borrelia miyamotoi Infections

    OpenAIRE

    Sin Hang Lee; Vigliotti, Jessica S.; Vigliotti, Veronica S; William Jones; Moorcroft, Thomas A.; Katherine Lantsman

    2014-01-01

    A highly conserved 357-bp segment of the 16S ribosomal RNA gene (16S rDNA) of Borrelia burgdorferi sensu lato and the correspondent 358-bp segment of the Borrelia miyamotoi gene were amplified by a single pair of nested polymerase chain reaction (PCR) primers for detection, and the amplicons were used as the templates for direct Sanger DNA sequencing. Reliable molecular diagnosis of these borreliae was confirmed by sequence alignment analysis of the hypervariable regions of the PCR amplicon,...

  9. Characterization of three different clusters of 18S-26S ribosomal DNA genes in the sea urchin P. lividus: Genetic and epigenetic regulation synchronous to 5S rDNA.

    Science.gov (United States)

    Bellavia, Daniele; Dimarco, Eufrosina; Caradonna, Fabio

    2016-04-15

    We previously reported the characterization 5S ribosomal DNA (rDNA) clusters in the common sea urchin Paracentrotus lividus and demonstrated the presence of DNA methylation-dependent silencing of embryo specific 5S rDNA cluster in adult tissue. In this work, we show genetic and epigenetic characterization of 18S-26S rDNA clusters in this specie. The results indicate the presence of three different 18S-26S rDNA clusters with different Non-Transcribed Spacer (NTS) regions that have different chromosomal localizations. Moreover, we show that the two largest clusters are hyper-methylated in the promoter-containing NTS regions in adult tissues, as in the 5S rDNA. These findings demonstrate an analogous epigenetic regulation in small and large rDNA clusters and support the logical synchronism in building ribosomes. In fact, all the ribosomal RNA genes must be synchronously and equally transcribed to perform their unique final product.

  10. 新疆达坂城盐湖中度嗜盐菌的16SrDNA序列研究%The 16S rDNA Sequence Research of Moderately Halophilic Bacteria from Dabancheng Saline Lake in Xinjiang

    Institute of Scientific and Technical Information of China (English)

    刘会强; 吕建江

    2008-01-01

    中度嗜盐菌作为一类微生物资源,已经在很多方面应用.从新疆达坂城盐湖样品中分离得到17株中度嗜盐菌.其中11株为革兰氏阳性,6株为革兰氏阴性,并完成表型和16S rDNA序列的测定.其表型特征和16S rDNA序列分析结果表明这些菌分别属于Halomonas、Bacillus、Salinlcoccus、Halobacillus、Marinococcus、Thalassobacillus、Nesterenkonia属,其中大部分属于Halomonas属.

  11. 结合宏基因组末端随机测序和16S rDNA技术分析温室黄瓜根围土壤细菌多样性%Analysis of bacterial diversity in rhizosphere of cucumber in greenhouse by the methods of metagenomic end-random sequencing and 16S rDNA technology

    Institute of Scientific and Technical Information of China (English)

    赵志祥; 罗坤; 陈国华; 杨宇红; 茆振川; 刘二明; 谢丙炎

    2010-01-01

    土壤细菌在温室土壤环境中具有十分重要的生态功能,与温室作物以及微生物内部存在互作关系.研究土壤细菌的群落结构组成,有助于了解土地利用变化与生态环境效应之间的关系.结合 16S rRNA基因克隆文库和宏基因组末端测序对温室黄瓜根围土壤细菌的多样性进行了分析.在16S文库中,根据97%的序列相似性水平划分OTU,共有35个OTU,其中优势菌群是γ-Proteobacteria,其次为Firmicutes,Bacillus为优势细菌.在纲分类水平上,16S文库和宏基因组末端测序结果均包含γ-Proteobacteria、α-Proteobacteria、δ-Proteobacteria、β-Proteobacteria、Actinomycetales和Firmicutes,各纲比例有差别;在优势种群属水平上,末端测序的结果包含的属多于16S文库(40>35);在优势细菌种类上,两者反映的结果一致,均为Bacillus.但是,宏基因组末端测序包含了大多数的弱势种群,更能反映细菌多样性的真实水平.与露地土壤细菌16S文库相比较,土壤细菌多样性降低,这可能与温室多年连作,种植蔬菜种类单一直接相关.

  12. Ribosomal DNA gene and phylogenetic relationships of Diplura and lower Hexapods

    Institute of Scientific and Technical Information of China (English)

    LUAN; Yunxia; (栾云霞); ZHANG; Yaping; (张亚平); YUE; Qiaoyun; (岳巧云); ANG; Junfeng; (庞峻峰); XIE; Rongdong; (谢荣栋); YIN; Wenying; (尹文英)

    2003-01-01

    The monophyly of Diplura and its phylogenetic relationship with other hexapods are important for understanding the phylogeny of Hexapoda. The complete 18SrRNA gene and partial 28SrRNA gene (D3-D5 region) from 2 dipluran species (Campodeidae and Japygidae), 2 proturan species, 3 collembolan species, and 1 locust species were sequenced. Combining related sequences in GenBank, phylogenetic trees of Hexapoda were constructed by MP method using a crustacean Artemia salina as an outgroup. The results indicated that: (i) the integrated data of 18SrDNA and 28SrDNA could provide better phylogenetic information, which well supported the monophyly of Diplura; (ii) Diplura had a close phylogenetic relationship to Protura with high bootstrap support.

  13. ANALYSIS OF FUNGI IN MUSHROOM COMPOST USING PCR AND TGGE OF RIBOSOMAL DNA

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The fungal communities in mushroom compost phase Ⅱ was assessed using a combination of PCR amplification and sequencing of 18S rDNA from fungal isolates and "nested" PCR-TGGE analysis on the basis of DNA directly extracted from compost samples. The diversity of cultivated fungi isolated from compost samples was low. A total of 11 isolates were related to only 2 different species. One species, Chaetomium elatum, was identified within 10 isolates, and the other, with high similarity belonged to Penicillium expansum. The fungal flora associated with mushroom compost was then monitored with "nested" PCR-TGGE. The patterns obtained revealed the more complex existence of fungal communities from the original compost samples than from thoses enriched with food waste and cow slurry.

  14. Identification of Dermatophyte Species by 28S Ribosomal DNA Sequencing with a Commercial Kit

    Science.gov (United States)

    Ninet, Béatrice; Jan, Isabelle; Bontems, Olympia; Léchenne, Barbara; Jousson, Olivier; Panizzon, Renato; Lew, Daniel; Monod, Michel

    2003-01-01

    We have shown that dermatophyte species can be easily identified on the basis of a DNA sequence encoding a part of the large-subunit (LSU) rRNA (28S rRNA) by using the MicroSeq D2 LSU rRNA Fungal Sequencing Kit. Two taxa causing distinct dermatophytoses were clearly distinguished among isolates of the Trichophyton mentagrophytes species complex. PMID:12574293

  15. Identification of Dermatophyte Species by 28S Ribosomal DNA Sequencing with a Commercial Kit

    OpenAIRE

    Ninet, Béatrice; Jan, Isabelle; Bontems, Olympia; Léchenne, Barbara; Jousson, Olivier; Panizzon, Renato; Lew, Daniel; Monod, Michel

    2003-01-01

    We have shown that dermatophyte species can be easily identified on the basis of a DNA sequence encoding a part of the large-subunit (LSU) rRNA (28S rRNA) by using the MicroSeq D2 LSU rRNA Fungal Sequencing Kit. Two taxa causing distinct dermatophytoses were clearly distinguished among isolates of the Trichophyton mentagrophytes species complex.

  16. Rapid Concerted Evolution of Nuclear Ribosomal DNA in Two Tragopogon Allopolyploids of Recent and Recurrent Origin

    OpenAIRE

    Kovarik, A; Pires, J. C.; Leitch, A. R.; Lim, K. Y.; Sherwood, A M; Matyasek, R.; Rocca, J.; Soltis, D. E.; Soltis, P S

    2005-01-01

    We investigated concerted evolution of rRNA genes in multiple populations of Tragopogon mirus and T. miscellus, two allotetraploids that formed recurrently within the last 80 years following the introduction of three diploids (T. dubius, T. pratensis, and T. porrifolius) from Europe to North America. Using the earliest herbarium specimens of the allotetraploids (1949 and 1953) to represent the genomic condition near the time of polyploidization, we found that the parental rDNA repeats were in...

  17. Rare Events of Intragenus and Intraspecies Horizontal Transfer of the 16S rRNA Gene.

    Science.gov (United States)

    Tian, Ren-Mao; Cai, Lin; Zhang, Wei-Peng; Cao, Hui-Luo; Qian, Pei-Yuan

    2015-07-27

    Horizontal gene transfer (HGT) of operational genes has been widely reported in prokaryotic organisms. However, informational genes such as those involved in transcription and translation processes are very difficult to be horizontally transferred, as described by Woese's complexity hypothesis. Here, we analyzed all of the completed prokaryotic genome sequences (2,143 genomes) in the NCBI (National Center for Biotechnology Information) database, scanned for genomes with high intragenomic heterogeneity of 16S rRNA gene copies, and explored potential HGT events of ribosomal RNA genes based on the phylogeny, genomic organization, and secondary structures of the ribosomal RNA genes. Our results revealed 28 genomes with relatively high intragenomic heterogeneity of multiple 16S rRNA gene copies (lowest pairwise identity 16S rRNA gene only occurred at intragenus or intraspecies levels, which is quite different from the HGT of operational genes. Our results improve our understanding regarding the exchange of informational genes.

  18. Physical localisation of repetitive DNA sequences in Alstroemeria: karyotyping of two species with species-specific and ribosomal DNA.

    Science.gov (United States)

    Kamstra, S A; Kuipers, A G; De Jeu, M J; Ramanna, M S; Jacobsen, E

    1997-10-01

    Fluorescence in situ hybridization (FISH) was used to localise two species-specific repetitive DNA sequences, A001-I and D32-13, and two highly conserved 25S and 5S rDNA sequences on the metaphase chromosomes of two species of Alstroemeria. The Chilean species, Alstroemeria aurea (2n = 16), has abundant constitutive heterochromatin, whereas the Brazilian species, Alstroemeria inodora, has hardly any heterochromatin. The A. aurea specific A001-I probe hybridized specifically to the C-band regions on all chromosomes. The FISH patterns on A. inodora chromosomes using species-specific probe D32-13 resembled the C-banding pattern and the A001-I pattern on A. aurea chromosomes. There were notable differences in number and distribution of rDNA sites between the two species. The 25S rDNA probe revealed 16 sites in A. aurea that closely colocalised with A001-I sites and 12 in A. inodora that were predominantly detected in the centromeric regions. FISH karyotypes of the two Alstroemeria species were constructed accordingly, enabling full identification of all individual chromosomes. These FISH karyotypes will be useful for monitoring the chromosomes of both Alstroemeria species in hybrids and backcross derivatives. PMID:9352644

  19. Lyme disease caused by Borrelia burgdorferi with two homeologous 16S rRNA genes: a case report

    Directory of Open Access Journals (Sweden)

    Lee SH

    2016-04-01

    Full Text Available Sin Hang Lee,1,21Pathology Department, Milford Hospital, Milford, CT, USA; 2Milford Molecular Diagnostics, Milford, CT, USA Abstract: Lyme disease (LD, the most common tick-borne disease in North America, is believed to be caused exclusively by Borrelia burgdorferi sensu stricto and is usually diagnosed by clinical evaluation and serologic assays. As reported previously in a peer-reviewed article, a 13-year-old boy living in the Northeast of the USA was initially diagnosed with LD based on evaluation of his clinical presentations and on serologic test results. The patient was treated with a course of oral doxycycline for 28 days, and the symptoms resolved. A year later, the boy developed a series of unusual symptoms and did not attend school for 1 year. A LD specialist reviewed the case and found the serologic test band patterns nondiagnostic of LD. The boy was admitted to a psychiatric hospital. After discharge from the psychiatric hospital, a polymerase chain reaction test performed in a winter month when the boy was 16 years old showed a low density of B. burgdorferi sensu lato in the blood of the patient, confirmed by partial 16S rRNA (ribosomal RNA gene sequencing. Subsequent DNA sequencing analysis presented in this report demonstrated that the spirochete isolate was a novel strain of B. burgdorferi with two homeologous 16S rRNA genes, which has never been reported in the world literature. This case report shows that direct DNA sequencing is a valuable tool for reliable molecular diagnosis of Lyme and related borrelioses, as well as for studies of the diversity of the causative agents of LD because LD patients infected by a rare or novel borrelial variant may produce an antibody pattern that can be different from the pattern characteristic of an infection caused by a typical B. burgdorferi sensu stricto strain. Keywords: Lyme disease, Borrelia burgdorferi, homeologous 16S rRNA genes, DNA sequencing

  20. Identification of Ustilago cynodontis as a new producer of glycolipid biosurfactants, mannosylerythritol lipids, based on ribosomal DNA sequences.

    Science.gov (United States)

    Morita, Tomotake; Konishi, Masaaki; Fukuoka, Tokuma; Imura, Tomohiro; Kitamoto, Dai

    2008-01-01

    Mannosylerythritol lipids (MELs) are one of the most promising glycolipid biosurfactants known because of their multifunctionality and biocompatibility. The search for novel producers of MELs was undertaken based on the analysis of ribosomal DNA sequences on basidiomycetous yeasts. The bermuda grass smut fungus Ustilago cynodontis NBRC 7530, which taxonomically relates to Pseudozyma shanxiensis known as a MEL-C producer, was found to accumulate glycolipids in the cultured medium. Under a shake flask culture with soybean oil, the amount of the glycolipids was 1.4 g/L for 7 days at 25 degrees C. As a result of the structural characterization, the main glycolipids was identified as 4-O-[(4'-O-acetyl-3'-O-alka(e)noyl-2'-O-butanoyl)-beta-D-mannopyranosyl]-D-erythritol, and the major fatty acids were C(14) and C(16) ones. The glycolipid was highly hydrophilic MEL-C, and very similar to those produced by P. shanxiensis. The fungi of the genus Ustilago are thus likely to be potential producers of MELs as well as the yeasts of the genus Pseudozyma. PMID:18781055

  1. Genetic heterogeneity and phylogeny of Trichuris spp. from captive non-human primates based on ribosomal DNA sequence data.

    Science.gov (United States)

    Cavallero, Serena; De Liberato, Claudio; Friedrich, Klaus G; Di Cave, David; Masella, Valentina; D'Amelio, Stefano; Berrilli, Federica

    2015-08-01

    Nematodes of the genus Trichuris, known as whipworms, are recognized to infect numerous mammalian species including humans and non-human primates. Several Trichuris spp. have been described and species designation/identification is traditionally based on host-affiliation, although cross-infection and hybridization events may complicate species boundaries. The main aims of the present study were to genetically characterize adult Trichuris specimens from captive Japanese macaques (Macaca fuscata) and grivets (Chlorocebus aethiops), using the ribosomal DNA (ITS) as molecular marker and to investigate the phylogeny and the extent of genetic variation also by comparison with data on isolates from other humans, non-human primates and other hosts. The phylogenetic analysis of Trichuris sequences from M. fuscata and C. aethiops provided evidences of distinct clades and subclades thus advocating the existence of additional separated taxa. Neighbor Joining and Bayesian trees suggest that specimens from M. fuscata may be distinct from, but related to Trichuris trichiura, while a close relationship is suggested between the subclade formed by the specimens from C. aethiops and the subclade formed by T. suis. The tendency to associate Trichuris sp. to host species can lead to misleading taxonomic interpretations (i.e. whipworms found in primates are identified as T. trichiura). The results here obtained confirm previous evidences suggesting the existence of Trichuris spp. other than T. trichiura infecting non-human living primates. PMID:26066463

  2. Genetic heterogeneity and phylogeny of Trichuris spp. from captive non-human primates based on ribosomal DNA sequence data.

    Science.gov (United States)

    Cavallero, Serena; De Liberato, Claudio; Friedrich, Klaus G; Di Cave, David; Masella, Valentina; D'Amelio, Stefano; Berrilli, Federica

    2015-08-01

    Nematodes of the genus Trichuris, known as whipworms, are recognized to infect numerous mammalian species including humans and non-human primates. Several Trichuris spp. have been described and species designation/identification is traditionally based on host-affiliation, although cross-infection and hybridization events may complicate species boundaries. The main aims of the present study were to genetically characterize adult Trichuris specimens from captive Japanese macaques (Macaca fuscata) and grivets (Chlorocebus aethiops), using the ribosomal DNA (ITS) as molecular marker and to investigate the phylogeny and the extent of genetic variation also by comparison with data on isolates from other humans, non-human primates and other hosts. The phylogenetic analysis of Trichuris sequences from M. fuscata and C. aethiops provided evidences of distinct clades and subclades thus advocating the existence of additional separated taxa. Neighbor Joining and Bayesian trees suggest that specimens from M. fuscata may be distinct from, but related to Trichuris trichiura, while a close relationship is suggested between the subclade formed by the specimens from C. aethiops and the subclade formed by T. suis. The tendency to associate Trichuris sp. to host species can lead to misleading taxonomic interpretations (i.e. whipworms found in primates are identified as T. trichiura). The results here obtained confirm previous evidences suggesting the existence of Trichuris spp. other than T. trichiura infecting non-human living primates.

  3. A Nuclear Ribosomal DNA Phylogeny of Acer Inferred with Maximum Likelihood, Splits Graphs, and Motif Analysis of 606 Sequences

    Directory of Open Access Journals (Sweden)

    Guido W. Grimm

    2006-01-01

    Full Text Available The multi-copy internal transcribed spacer (ITS region of nuclear ribosomal DNA is widely used to infer phylogenetic relationships among closely related taxa. Here we use maximum likelihood (ML and splits graph analyses to extract phylogenetic information from ~ 600 mostly cloned ITS sequences, representing 81 species and subspecies of Acer, and both species of its sister Dipteronia. Additional analyses compared sequence motifs in Acer and several hundred Anacardiaceae, Burseraceae, Meliaceae, Rutaceae, and Sapindaceae ITS sequences in GenBank. We also assessed the effects of using smaller data sets of consensus sequences with ambiguity coding (accounting for within-species variation instead of the full (partly redundant original sequences. Neighbor-nets and bipartition networks were used to visualize conflict among character state patterns. Species clusters observed in the trees and networks largely agree with morphology-based classifications; of de Jong’s (1994 16 sections, nine are supported in neighbor-net and bipartition networks, and ten by sequence motifs and the ML tree; of his 19 series, 14 are supported in networks, motifs, and the ML tree. Most nodes had higher bootstrap support with matrices of 105 or 40 consensus sequences than with the original matrix. Within-taxon ITS divergence did not differ between diploid and polyploid Acer, and there was little evidence of differentiated parental ITS haplotypes, suggesting that concerted evolution in Acer acts rapidly.

  4. Helicobacter species ribosomal DNA in the pancreas, stomach and duodenum of pancreatic cancer patients

    Institute of Scientific and Technical Information of China (English)

    Hans-Olof Nilsson; Unne Stenram; Ingemar Ihse; Torkel Wadstr(o)m

    2006-01-01

    AIM: To determine whether gastric and enteric Helico-bacter species are associated with pancreatic cancer.METHODS: Patients with exocrine pancreatic cancer(n = 40), neuroendocrine cancer (n = 14), multipleendocrine neoplasia type 1 (n = 8), and chronic pan-creatitis (n = 5) were studied. Other benign pancreat-ic diseases (n = 10) and specimens of normal pancre-as (n = 7) were included as controls. Pancreatic tissuespecimens were analyzed by Helicobacter-specificPCR-assay and products were characterized by dena-turing gradient electrophoresis and DNA-sequencing.From a subset of the pancreatic cancer patients, gas-tric and/or duodenal tissue as well as gallbladder andductus choledochus tissue were analyzed. Gallbladderand choledochus samples were included as controls.Stomach and duodenum samples were investigated toanalyze whether a gastric helicobacter might dissemi-nate to the pancreas in pancreatic cancer patients.Pancreatic specimens were analyzed by Bacteroides-specific PCR for detecting the translocation of indig-enous gut microbes to the diseased pancreas.RESULTS: Helicobacter DNA was detected in pancreas(tumor and/or surrounding tissue) of 75% of patientswith exocrine cancer, 57% of patients with neuro-endocrine cancer, 38% of patients with multiple eh-docrine neoplasia, and 60% of patients with chronicpancreatitis. All samples from other benign pancreaticdiseases and normal pancreas were negative. Thirty-three percent of the patients were helicobacter-positive in gastroduodenal specimens. Surprisingly,H. bilis was identified in 60% of the positive gastro-duodenal samples. All gallbladder and ductus cho-ledochus specimens were negative for helicobacter.Bacteroides PCR-assay was negative for all pancreaticsamples.CONCLUSION: Helicobacter DNA commonly detectedin pancreatic cancer suggests a possible role of theemerging pathogens in the development of chronicpancreatitis and pancreatic cancer.

  5. Ribosomal DNA is active in different B chromosome variants of the grasshopper Eyprepocnemis plorans.

    Science.gov (United States)

    Ruíz-Estévez, Mercedes; López-León, M Dolores; Cabrero, Josefa; Camacho, Juan Pedro M

    2013-09-01

    B chromosomes are considered to be genetically inert elements. However, some of them are able to show nucleolus organizer region (NOR) activity, as detected by both cytological and molecular means. The grasshopper Eyprepocnemis plorans shows a B chromosome polymorphism characterized by the existence of many B variants. One of them, B24, shows NOR activity in about half of B-carrying males in the Torrox population. Molecular data have suggested the recent origin for B chromosomes in this species, and on this basis it would be expected that NOR activity was widespread among the different B variants. Here we test this hypothesis in four different B chromosome variants (B1, B2, B5, and B24) from 11 natural populations of the grasshopper E. plorans covering the south and east of the Iberian Peninsula plus the Balearic Islands. We used two different approaches: (1) the cytological observation of nucleoli attached to the distal region of the B chromosome (where the rDNA is located), and (2) the molecular detection of the rDNA transcripts carrying an adenine insertion characteristic of B chromosome ITS2 sequences. The results showed NOR expression not only for B24 but also for the B1 and B2 variants. However, the level of B-NOR expression in these latter variants, measured by the proportion of cells showing nucleoli attached to the B chromosomes, was much lower than that previously reported for B24. This suggests the possibility that structural or genetic background conditions are enhancing the expressivity of the rDNA in the B24 variant.

  6. Authentication of ruta graveolens and its adulterant using internal transcribed spacer (its) sequences of nuclear ribosomal DNA

    International Nuclear Information System (INIS)

    Ruta graveolens L. (Rutaceae) is commonly known as 'Sudab' which is well known for hippocratic medicine and is commonly used in indigenous health-care system in India. Euphorbia dracunculoides Lam. (Euphorbiaceae) in raw drug trading has almost similar morphology to R. graveolens in dried state, is being sold locally or used clinically as an adulterant of R. graveolens (genuine) at a relatively low price under the same name 'Sudab' which has ultimately reduced the efficacy and quality of this herb. The internal transcribed spacer (ITS) sequence of nuclear ribosomal DNA gene of genuine and adulterant were sequenced and analyzed to assess species admixture in raw drug trading of genuine herbal drug. The BLAST search results of ITS sequence of genuine sample of 'Sudab' i.e., R. graveolens showed 99% similarity to the sequence of R. graveolens, however, E. dracunculoides showed 100% similarity to the species of Euphorbia and did not show any similarity with R. graveolens. The sequence alignment of both species was entirely different to each other. Phylogenetic analysis based on ITS sequence of adulterant sample i.e., E. dracunculoides together with sequences of Euphorbia species available in the GenBank has also clearly showed its nesting within the Euphorbia tree. The generated ITS sequences of both samples in the present study may be referred hereafter as species-specific DNA barcode signature, which can be used in authenticating and validating the exact species identities to discriminate the genuine sample of 'Sudab' from its adulterants if any available to guarantee the quality and purity of this drug in the herbal drug market. (author)

  7. Bacterial Diversity Studies Using the 16S rRNA Gene Provide a Powerful Research-Based Curriculum for Molecular Biology Laboratory

    Directory of Open Access Journals (Sweden)

    Sarah M. Boomer

    2009-12-01

    Full Text Available We have developed a ten-week curriculum for molecular biology that uses 16S ribosomal RNA genes to characterize and compare novel bacteria from hot spring communities in Yellowstone National Park. The 16S rRNA approach bypasses selective culture-based methods. Our molecular biology course offered the opportunity for students to learn broadly applicable methods while contributing to a long-term research project. Specifically, students isolated and characterized clones that contained novel 16S rRNA inserts using restriction enzyme, DNA sequencing, and computer-based phylogenetic methods. In both classes, students retrieved novel bacterial 16S rRNA genes, several of which were most similar to Green Nonsulfur bacterial isolates. During class, we evaluated student performance and mastery of skills and concepts using quizzes, formal lab notebooks, and a broad project assignment. For this report, we also assessed student performance alongside data quality and discussed the significance, our goal being to improve both research and teaching methods.

  8. Bacterial Diversity Studies Using the 16S rRNA Gene Provide a Powerful Research-Based Curriculum for Molecular Biology Laboratory

    Directory of Open Access Journals (Sweden)

    Bryan E. Dutton

    2002-12-01

    Full Text Available We have developed a ten-week curriculum for molecular biology that uses 16S ribosomal RNA genes to characterize and compare novel bacteria from hot spring communities in Yellowstone National Park. The 16S rRNA approach bypasses selective culture-based methods. Our molecular biology course offered the opportunity for students to learn broadly applicable methods while contributing to a long-term research project. Specifically, students isolated and characterized clones that contained novel 16S rRNA inserts using restriction enzyme, DNA sequencing, and computer-based phylogenetic methods. In both classes, students retrieved novel bacterial 16S rRNA genes, several of which were most similar to Green Nonsulfur bacterial isolates. During class, we evaluated student performance and mastery of skills and concepts using quizzes, formal lab notebooks, and a broad project assignment. For this report, we also assessed student performance alongside data quality and discussed the significance, our goal being to improve both research and teaching methods.

  9. Phylogenetic relationship of Podocopida (Ostracoda: Podocopa) based on 18S ribosomal DNA sequences

    Institute of Scientific and Technical Information of China (English)

    YU Na; ZHAO Meiying; CHEN Liqiao; YANG Pin

    2006-01-01

    Nucleotide sequences from 18S rDNA of 11 ostracodes, which represent four suborders and six superfamilies ofpodocopidan, were determined. The phylogenetic relationships were analyzed based on three kinds of methods (maximum-likelihood, maximum-parsimony,and neighbor-joining), and the three topologies gained were basically similar. The results have showed that (1) a monophyletic Podocopida was supported strongly; (2) the phylogenetic relationships of four suborders were (Darwinulocopina plus (Bairdiocopina plus (Cytherocopina plus Cypridocopina))), which indicated that a close relationship between Cytherocopina and Cypridocopina, and Darwinulocopina had separated early from the main podocopinan; (3) Cypridocopinan formed a monophyletic group, among which the phylogenetic relationship of three superfamilies was (Cypridoidea plus (Macrocypridoidea plus Pontocypridoidea)).

  10. Evaluation of PCR-generated chimeras, mutations, and heteroduplexes with 16S rRNA gene-based cloning.

    Science.gov (United States)

    Qiu, X; Wu, L; Huang, H; McDonel, P E; Palumbo, A V; Tiedje, J M; Zhou, J

    2001-02-01

    To evaluate PCR-generated artifacts (i.e., chimeras, mutations, and heteroduplexes) with the 16S ribosomal DNA (rDNA)-based cloning approach, a model community of four species was constructed from alpha, beta, and gamma subdivisions of the division Proteobacteria as well as gram-positive bacterium, all of which could be distinguished by HhaI restriction digestion patterns. The overall PCR artifacts were significantly different among the three Taq DNA polymerases examined: 20% for Z-Taq, with the highest processitivity; 15% for LA-Taq, with the highest fidelity and intermediate processitivity; and 7% for the conventionally used DNA polymerase, AmpliTaq. In contrast to the theoretical prediction, the frequency of chimeras for both Z-Taq (8.7%) and LA-Taq (6.2%) was higher than that for AmpliTaq (2.5%). The frequencies of chimeras and of heteroduplexes for Z-Taq were almost three times higher than those of AmpliTaq. The total PCR artifacts increased as PCR cycles and template concentrations increased and decreased as elongation time increased. Generally the frequency of chimeras was lower than that of mutations but higher than that of heteroduplexes. The total PCR artifacts as well as the frequency of heteroduplexes increased as the species diversity increased. PCR artifacts were significantly reduced by using AmpliTaq and fewer PCR cycles (fewer than 20 cycles), and the heteroduplexes could be effectively removed from PCR products prior to cloning by polyacrylamide gel purification or T7 endonuclease I digestion. Based upon these results, an optimal approach is proposed to minimize PCR artifacts in 16S rDNA-based microbial community studies.

  11. Directed gene copy number amplification in Pichia pastoris by vector integration into the ribosomal DNA locus.

    Science.gov (United States)

    Marx, Hans; Mecklenbräuker, Astrid; Gasser, Brigitte; Sauer, Michael; Mattanovich, Diethard

    2009-12-01

    The yeast Pichia pastoris is a widely used host organism for heterologous protein production. One of the basic steps for strain improvement is to ensure a sufficient level of transcription of the heterologous gene, based on promoter strength and gene copy number. To date, high-copy-number integrants of P. pastoris are achievable only by screening of random events or by cloning of gene concatemers. Methods for rapid and reliable multicopy integration of the expression cassette are therefore desirable. Here we present such a method based on vector integration into the rDNA locus and post-transformational vector amplification by repeated selection on increased antibiotic concentrations. Data are presented for two exemplary products: human serum albumin, which is secreted into the supernatant, and human superoxide dismutase, which is accumulated in the cytoplasm of the cells. The striking picture evolving is that intracellular protein production is tightly correlated with gene copy number, while use of the secretory pathway introduces a high clonal variability and the correlation with gene copy number is valid only for low gene copy numbers. PMID:19799640

  12. Phylogeny and biogeography of Alyssum (Brassicaceae) based on nuclear ribosomal ITS DNA sequences

    Indian Academy of Sciences (India)

    Yan Li; Yan Kong; Zhe Zhang; Yanqiang Yin; Bin Liu; Guanghui Lv; Xiyong Wang

    2014-08-01

    The genus Alyssum consists of about 195 species native to Europe, Asia and northern Africa. All species were assigned to six sections. Previous molecular phylogeny studies indicate that Alyssum is polyphyletic. However, the divergence time and dispersal of the genus are not well studied. In this study, the phylogenetic relationships within the genus Alyssum were studied with nrDNA ITS sequences obtained from five sections. The divergence time was estimated by fossil calibration and the biogeography was examined by spread analysis. The phylogeny indicated two main lineages: lineage 1 includes the section of Alyssum, Gamosepalum and Psilonema; lineage 2 includes the section of Odontarrhena, Meniocus and Clypeola. The phylogenetic relationship was not congruent with the previous sectional classifications. The age of Alyssum was dated to the upper Miocene. Molecular data suggested the diversification of Alyssum in Mediterranean areas and wide-ranging distribution such as North Africa, eastward into Central Asia and immigration into North America. Climatic aridification and arid/semiarid areas established in the Pliocene/Pleistocene could have provided favourable conditions for the migration and diversification of Alyssum.

  13. 一株微生物采油菌的16S rDNA鉴定和绿色荧光蛋白分子标记%Identification through 16S rDNA Sequence Analysis and Marking with Green Fluorescent Protein of an Isolated Strain for Microbial Enhanced Oil Recovery

    Institute of Scientific and Technical Information of China (English)

    王欲晓; 庄文昌; 王靖

    2011-01-01

    A strain(named YX) isolated from Shengli Oil Field,capable of producing polysaccharides for Microbial Enhanced Oil Recovery(MEOR) ,has been identified as a member of Enterobacter sp.through 16SrDNA sequence analysis.Recombinant plasmid of pET-30a(+) -EGFP has been transferred into natural strain YX using cold CaCl2 method,and green fluorescent expressed by engineered strain YX containing green fluorescent protein(GFP) gene has been observed and monitored.This study provides a new approach that can track and monitor the dynamic data of a goal strain for enhanced oil recovery.%筛选到一株高效生产多糖的YX菌,油田先导试验证明该菌可以用于微生物调剖提高原油采收率(Microbial Enhanced Oil Recovery,MEOR).经16SrDNA分析鉴定,YX菌属于肠内杆菌属(Enterobacter.),为跟踪监测其动态信息,构建表达绿色荧光蛋白(green fluorescent protein,GFP)的重组质粒pET-30a(+)-EGFP,利用CaCl2法将其转化至YX菌,利用荧光显微镜可以观察到重组YX(GFP)工程菌的绿色荧光.结果表明YX菌可以被绿色荧光蛋白基因标记,用于微生物采油研究.

  14. Phylogeographical studies of Ascaris spp. based on ribosomal and mitochondrial DNA sequences.

    Directory of Open Access Journals (Sweden)

    Serena Cavallero

    Full Text Available BACKGROUND: The taxonomic distinctiveness of Ascaris lumbricoides and A. suum, two of the world's most significant nematodes, still represents a much-debated scientific issue. Previous studies have described two different scenarios in transmission patterns, explained by two hypotheses: (1 separated host-specific transmission cycles in highly endemic regions, (2 a single pool of infection shared by humans and pigs in non-endemic regions. Recently, A. suum has been suggested as an important cause of human ascariasis in endemic areas such as China, where cross-infections and hybridization have also been reported. The main aims of the present study were to investigate the molecular epidemiology of human and pig Ascaris from non-endemic regions and, with reference to existing data, to infer the phylogenetic and phylogeographic relationships among the samples. METHODOLOGY: 151 Ascaris worms from pigs and humans were characterized using PCR-RFLP on nuclear ITS rDNA. Representative geographical sub-samples were also analysed by sequencing a portion of the mitochondrial cox1 gene, to infer the extent of variability at population level. Sequence data were compared to GenBank sequences from endemic and non-endemic regions. PRINCIPAL FINDINGS: No fixed differences between human and pig Ascaris were evident, with the exception of the Slovak population, which displays significant genetic differentiation. The RFLP analysis confirmed pig as a source of human infection in non-endemic regions and as a corridor for the promulgation of hybrid genotypes. Epidemiology and host-affiliation seem not to be relevant in shaping molecular variance. Phylogenetic and phylogeographical analyses described a complex scenario, involving multiple hosts, sporadic contact between forms and an ancestral taxon referable to A. suum. CONCLUSIONS/SIGNIFICANCE: These results suggest the existence of homogenizing gene flow between the two taxa, which appear to be variants of a single

  15. Interplay of ribosomal DNA loci in nucleolar dominance: dominant NORs are up-regulated by chromatin dynamics in the wheat-rye system.

    Directory of Open Access Journals (Sweden)

    Manuela Silva

    Full Text Available BACKGROUND: Chromatin organizational and topological plasticity, and its functions in gene expression regulation, have been strongly revealed by the analysis of nucleolar dominance in hybrids and polyploids where one parental set of ribosomal RNA (rDNA genes that are clustered in nucleolar organizing regions (NORs, is rendered silent by epigenetic pathways and heterochromatization. However, information on the behaviour of dominant NORs is very sparse and needed for an integrative knowledge of differential gene transcription levels and chromatin specific domain interactions. METHODOLOGY/PRINCIPAL FINDINGS: Using molecular and cytological approaches in a wheat-rye addition line (wheat genome plus the rye nucleolar chromosome pair 1R, we investigated transcriptional activity and chromatin topology of the wheat dominant NORs in a nucleolar dominance situation. Herein we report dominant NORs up-regulation in the addition line through quantitative real-time PCR and silver-staining technique. Accompanying this modification in wheat rDNA trascription level, we also disclose that perinucleolar knobs of ribosomal chromatin are almost transcriptionally silent due to the residual detection of BrUTP incorporation in these domains, contrary to the marked labelling of intranucleolar condensed rDNA. Further, by comparative confocal analysis of nuclei probed to wheat and rye NORs, we found that in the wheat-rye addition line there is a significant decrease in the number of wheat-origin perinucleolar rDNA knobs, corresponding to a diminution of the rDNA heterochromatic fraction of the dominant (wheat NORs. CONCLUSIONS/SIGNIFICANCE: We demonstrate that inter-specific interactions leading to wheat-origin NOR dominance results not only on the silencing of rye origin NOR loci, but dominant NORs are also modified in their transcriptional activity and interphase organization. The results show a cross-talk between wheat and rye NORs, mediated by ribosomal chromatin

  16. The ribosome biogenesis factor Nol11 is required for optimal rDNA transcription and craniofacial development in Xenopus.

    Directory of Open Access Journals (Sweden)

    John N Griffin

    2015-03-01

    Full Text Available The production of ribosomes is ubiquitous and fundamental to life. As such, it is surprising that defects in ribosome biogenesis underlie a growing number of symptomatically distinct inherited disorders, collectively called ribosomopathies. We previously determined that the nucleolar protein, NOL11, is essential for optimal pre-rRNA transcription and processing in human tissue culture cells. However, the role of NOL11 in the development of a multicellular organism remains unknown. Here, we reveal a critical function for NOL11 in vertebrate ribosome biogenesis and craniofacial development. Nol11 is strongly expressed in the developing cranial neural crest (CNC of both amphibians and mammals, and knockdown of Xenopus nol11 results in impaired pre-rRNA transcription and processing, increased apoptosis, and abnormal development of the craniofacial cartilages. Inhibition of p53 rescues this skeletal phenotype, but not the underlying ribosome biogenesis defect, demonstrating an evolutionarily conserved control mechanism through which ribosome-impaired craniofacial cells are removed. Excessive activation of this mechanism impairs craniofacial development. Together, our findings reveal a novel requirement for Nol11 in craniofacial development, present the first frog model of a ribosomopathy, and provide further insight into the clinically important relationship between specific ribosome biogenesis proteins and craniofacial cell survival.

  17. Assessment of phylogenetic relationship of rare plant species collected from Saudi Arabia using internal transcribed spacer sequences of nuclear ribosomal DNA.

    Science.gov (United States)

    Al-Qurainy, F; Khan, S; Nadeem, M; Tarroum, M; Alaklabi, A

    2013-01-01

    The rare and endangered plants of any country are important genetic resources that often require urgent conservation measures. Assessment of phylogenetic relationships and evaluation of genetic diversity is very important prior to implementation of conservation strategies for saving rare and endangered plant species. We used internal transcribed spacer sequences of nuclear ribosomal DNA for the evaluation of sequence identity from the available taxa in the GenBank database by using the Basic Local Alignment Search Tool (BLAST). Two rare plant species viz, Heliotropium strigosum claded with H. pilosum (98% branch support) and Pancratium tortuosum claded with P. tenuifolium (61% branch support) clearly. However, some species, viz Scadoxus multiflorus, Commiphora myrrha and Senecio hadiensis showed close relationships with more than one species. We conclude that nuclear ribosomal internal transcribed spacer sequences are useful markers for phylogenetic study of these rare plant species in Saudi Arabia.

  18. 棘阿米巴土壤分离株CB/S1内共生细菌的16SrDNA序列分析%Sequence Analysis of 16S rDNA Gene of Endosymbiont of Acanthamoeba sp.CB/S1 Isolated from Soil

    Institute of Scientific and Technical Information of China (English)

    玄英花; 崔春权; 郑善子

    2011-01-01

    The endosymbiont of Acanthamoeba sp. CB/S1 was identified by orcein-carmine staining and 16S rDNA sequence analysis. The endosymbiont bacteria were rod-shaped and darkly stained, and irregularly localized within the cytoplasm. The length of the 16S rDNA was 1534 bp and its DNA sequence was closely related to those of Candidatus A moebophilus asiaticus and A canthamoeba sp. KA/E21 with 98% homology. Phylogenetic analysis showed that the endosymbiont of CB/S1,the endosymbiont of KA/E21, Candidatus Amoebophilus asiaticus, the endosymbiont of Ixodes scapularis , and the endosymbiont of Encarsia pergandiella constitute a monophyletic lineage in phylogenetic tree.%用地衣红-卡红染色进行共生菌的形态观察,鉴定棘阿米巴CB/S1内共生细菌.克隆内共生细菌的16S rDNA基因,进行基因序列分析.结果 表明,经地衣红-卡红染色棘阿米巴CB/S1内共生细菌呈黑色和棒状,在胞质内不规则分布.棘阿米巴CB/S1内共生细菌的16S rDNA基因长1 534 bp,与类亚洲嗜阿米巴杆菌(Candidatus Amoebophilus asiaticus 5a2)和韩国棘阿米巴分离株 KA/E21内共生细菌的16S rDNA基因的同源性均为98%.进化树分析表明,棘阿米巴CB/S1内共生细菌与韩国棘阿米巴KA/E21内共生细菌、类亚洲嗜阿米巴杆菌、黑脚硬蜱内共生细菌和伯恩蚜小蜂内共生细菌等细菌构成单系.

  19. Absence of Helicobacter pylori high tetracycline resistant 16S rDNA AGA926-928TTC genotype in gastric biopsy specimens from dyspeptic patients of a city in the interior of São Paulo, Brazil

    Directory of Open Access Journals (Sweden)

    Suzuki Rodrigo

    2012-05-01

    Full Text Available Abstract Background Treatment effectiveness of Helicobacter pylori varies regionally and is decreasing worldwide, principally as a result of antibiotic resistant bacterium. Tetracycline is generally included in second line H. pylori eradication regimens. In Brazil, a high level of tetracycline resistance (TetR is mainly associated with AGA926-928TTC 16 S rDNA nucleotide substitutions. As H. pylori culture is fastidious, we investigated the primary occurrence of H. pylori 16 S rDNA high level TetR genotype using a molecular approach directly on gastric biopsies of dyspeptic patients attending consecutively at Hospital das Clinicas of Marilia, São Paulo, Brazil. Methods Gastric biopsy specimens of 68 peptic ulcer disease (PUD and 327 chronic gastritis (CG patients with a positive histological diagnosis of H. pylori were investigated for TetR 16 S rDNA genotype through a molecular assay based on amplification of a 16 S rDNA 545 bp fragment by polymerase chain reaction and HinfI restriction fragment length polymorphism (PCR/RFLP. Through this assay, AGA926-928TTC 16 S rDNA TetR genotype resulted in a three DNA fragment restriction pattern (281, 227 and 37 bp and its absence originated two DNA fragments (264 and 281 bp due to a 16 S rDNA conserved Hinf I restriction site. Results The 545 bp 16 S rDNA PCR fragment was amplified from 90% of gastric biopsies from histological H. pylori positive patients. HinfI RFLP revealed absence of the AGA926–928TTC H. pylori genotype and PCR products of two patients showed absence of the conserved 16 S rDNA HinfI restriction site. BLASTN sequence analysis of four amplicons (two conserved and two with an unpredicted HinfI restriction pattern revealed a 99% homology to H. pylori 16 S rDNA from African, North and South American bacterial isolates. A nucleotide substitution abolished the conserved HinfI restriction site in the two PCR fragments with unpredicted HinfI RFLP, resulting in an

  20. Molecular detection and sequence analysis on 16S ribosomal DNA of phytoplasma associated with mulberry yellow dwarf disease occurring in Anhui%安徽桑黄花型萎缩病植原体16S rDNA序列分析及分子检测

    Institute of Scientific and Technical Information of China (English)

    卢全有

    2010-01-01

    @@ 桑黄花型萎缩病(Mulbeny yellow dwarf diSease,MYD)是桑树上的主要病害,属国内植物重要的检疫性病害,曾对我国的蚕桑生产造成重大损 失.桑萎缩病是国际上首先被确定为由植原体引起的病害之一,由菱蚊叶蝉专化性传播[1].

  1. Interaction between the yeast mitochondrial and nuclear genomes influences the abundance of novel transcripts derived from the spacer region of the nuclear ribosomal DNA repeat.

    OpenAIRE

    Parikh, V S; Conrad-Webb, H; Docherty, R; Butow, R A

    1989-01-01

    We have identified stable transcripts from the so-called nontranscribed spacer region (NTS) of the nuclear ribosomal DNA repeat in certain respiration-deficient strains of Saccharomyces cerevisiae. These RNAs, which are transcribed from the same strand as is the 37S rRNA precursor, are 500 to 800 nucleotides long and extend from the 5' end of the 5S rRNA gene to three major termination sites about 1,780, 1,830, and 1,870 nucleotides from the 3' end of the 26S rRNA gene. A survey of various wi...

  2. Phylogenetic Relationships of Two Earth Tiger Tarantulas, Haplopelma lividum and H. longipes (Araneae, Theraphosidae, within the Infraorder Mygalomorph Using 28S Ribosomal DNA Sequences

    Directory of Open Access Journals (Sweden)

    Arin Ngamniyom

    2014-01-01

    Full Text Available Haplopelma lividum and H. longipes (Araneae: Mygalomorphae: Theraphosidae are tarantulas that are distributed throughout Southeast Asia and are important carnivorous predators in ecological systems. The present study aimed to examine the phylogenetic relationships between Mygalomorph spiders using 28S ribosomal DNA sequences. The molecular results supported the placement of both species within a common theraphosid taxon. However, when considering relationships between Haplopelma spp. and related genera, H. schmidti, H. lividum and H. longipes were not monophyletic, suggesting that molecular data are incongruent with phylogenies based on morphological characteristics. These results provide molecular data to help elucidate the phylogenetic relationships between theraphosid tarantulas.

  3. Single-step co-integration of multiple expressible heterologous genes into the ribosomal DNA of the methylotrophic yeast Hansenula polymorpha.

    Science.gov (United States)

    Klabunde, J; Diesel, A; Waschk, D; Gellissen, G; Hollenberg, C P; Suckow, M

    2002-05-01

    We have investigated the methylotrophic yeast Hansenula polymorpha as a host for the co-integration and expression of multiple heterologous genes using an rDNA integration approach. The ribosomal DNA (rDNA) of H. polymorpha was found to consist of a single rDNA cluster of about 50-60 repeats of an 8-kb unit located on chromosome II. A 2.4-kb segment of H. polymorpha rDNA encompassing parts of the 25S, the complete 5S and the non-transcribed spacer region between 25S and 18S rDNA was isolated and inserted into conventional integrative H. polymorpha plasmids harboring the Saccharomyces- cerevisiae-derived URA3 gene for selection. These rDNA plasmids integrated homologously into the rDNA repeats of a H. polymorpha (odc1) host as several independent clusters. Anticipating that this mode of multiple-cluster integration could be used for the simultaneous integration of several distinct rDNA plasmids, the host strain was co-transformed with a mixture of up to three different plasmids, all bearing the same URA3 selection marker. Transformations indeed resulted in mitotically stable strains harboring one, two, or all three plasmids integrated into the rDNA. The overall copy number of the plasmids integrated did not exceed the number of rDNA repeats present in the untransformed host strain, irrespective of the number of different plasmids involved. Strains harboring different plasmids co-expressed the introduced genes, resulting in functional proteins. Thus, this approach provides a new and attractive tool for the rapid generation of recombinant strains that simultaneously co-produce several proteins in desired stoichiometric ratios. PMID:12021801

  4. The utility of internally transcribed spacer 2 DNA sequences of the nuclear ribosomal gene for distinguishing sibling species of Trichogramma

    NARCIS (Netherlands)

    Stouthamer, R.; Hu, J.; Kan, van F.J.P.M.; Platner, G.R.; Pinto, J.D.

    1999-01-01

    The usefulness of the internally transcribed spacer 2 (ITS2) of the nuclear ribosomal gene complex is tested for providing taxonomic characters to identify Trichogramma species. The ITS2 sequences of a group of sibling species of the T. deion/T. pretiosum complexes were determined. A simple and prec

  5. Microvariation artifacts introduced by PCR and cloning of closely related 16S rRNA gene sequences

    NARCIS (Netherlands)

    Speksnijder, A.G.C.L.; Kowalchuk, G.A.; Jong, S. de; Kline, E.; Stephen, J.R.; Laanbroek, H.J.

    2001-01-01

    A defined template mixture of seven closely related 16S-rDNA clones was used in a PCR-cloning experiment to assess and track sources of artifactual sequence variation in 16S rDNA clone libraries. At least 14% of the recovered clones contained aberrations. Artifact sources were polymerase errors, a m

  6. Microvariation Artifacts Introduced by PCR and Cloning of Closely Related 16S rRNA Gene Sequences

    NARCIS (Netherlands)

    Speksnijder, A.G.C.L.; Kowalchuk, G.A.; Jong, de S.; Kline, E.; Stephen, J.R.; Laanbroek, H.J.

    2001-01-01

    A defined template mixture of seven closely related 16S-rDNA clones was used in a PCR-cloning experiment to assess and track sources of artifactual sequence variation in 16S rDNA clone libraries. At least 14% of the recovered clones contained aberrations. Artifact sources were polymerase errors, a m

  7. 山羊奇异变形杆菌的分离鉴定及16SrDNA和ZapA基因的PCR-RFLP分析%Isolation and identification of Proteus mirabilis from goat and the analysis of 16S rDNA and ZapA gene by PCR-RFLP

    Institute of Scientific and Technical Information of China (English)

    王豪举; 倪莉; 杨红军; 赵俊; 徐宗可; 徐强; 徐丽敏

    2011-01-01

    Five strains of pathogen were isolated from the infected goats. Swarming behaviour assays, biochemical, animal and antibiotic resistance tests were carried out to identify its properties. Then 16S rDNA and ZapA were cloned and sequenced and both 16S rDNA and ZapA were analyzed with PCR-PFLP after digestion by specific restriction enzymes. The data showed the field strains had the swarming behaviour,which were sensitive to amikacin and for- turn,the LDs0 in mice was from 2. 500 0× 10^7 CFU/mL to 4. 445 3× 10^7CFU/mL. The DNA sequencing showed 99. 5%-99.8% similarity with Proteus mirabilis for 16S rDNA and 95. 5% for ZapA gene; the segments from PCRRFLP analysis displayed no disparity with reference strain in number and size. The results indicate that the field strains are a member of Proteus rnirabilis with no polymorphism.%从发病山羊分离到5株病原菌,对分离株进行游散行为分析,生化试验、动物试验、药敏试验及16SrDNA和ZapA基因克隆测序,选用限制性内切酶对分离株16SrDNA和ZapA基因进行PCR-RFLP分析。结果表明分离株出现游散生长现象,对丁胺卡那霉素和复达欣敏感,小鼠LD5。为2.5000×10 ^7CFU/mL-4.4453×10^7CFU/mL;分离株16SrDNA与奇异变形杆菌的同源率为99.5%~99.8%,ZapA基N与奇异变形杆菌的同源率为99.5%;PCR—RFLP分析发现,分离株酶切片段数目和大小与标准株相同。结果表明分离株是奇异变形杆菌,多态性较为单一。

  8. Molecular Identification of Ptychodera flava (Hemichordata: Enteropneusta): Reconsideration in Light of Nucleotide Polymorphism in the 18S Ribosomal RNA Gene.

    Science.gov (United States)

    Urata, Makoto

    2015-06-01

    Seven nuclear and mitochondrial DNA markers were examined in 12 specimens of Ptychodera flava, a model acorn worm used in molecular biology, collected in Japan from three local populations with different modes of living. A comparison of intraspecific results did not show genetically isolated populations despite the species' enclave habitats and asexual reproduction. Moreover, both the nuclear 18S ribosomal RNA gene and mitochondrial 16S ribosomal RNA gene sequences were identical to those from Moorea in French Polynesia, nearly 10,000 kilometers away from Japan. I also provide the first definitive information regarding polymorphisms in 18S ribosomal RNA gene, the external transcribed spacer (ETS), internal transcribed spacers (ITS), and mitochondrial cytochrome c oxidase subunit 1 (mtCO1) sequence in hemichordates using newly designed primer sets, and I show both high larval vagility and certain criteria for the molecular identification of this species.

  9. Lyme disease caused by Borrelia burgdorferi with two homeologous 16S rRNA genes: a case report.

    Science.gov (United States)

    Lee, Sin Hang

    2016-01-01

    Lyme disease (LD), the most common tick-borne disease in North America, is believed to be caused exclusively by Borrelia burgdorferi sensu stricto and is usually diagnosed by clinical evaluation and serologic assays. As reported previously in a peer-reviewed article, a 13-year-old boy living in the Northeast of the USA was initially diagnosed with LD based on evaluation of his clinical presentations and on serologic test results. The patient was treated with a course of oral doxycycline for 28 days, and the symptoms resolved. A year later, the boy developed a series of unusual symptoms and did not attend school for 1 year. A LD specialist reviewed the case and found the serologic test band patterns nondiagnostic of LD. The boy was admitted to a psychiatric hospital. After discharge from the psychiatric hospital, a polymerase chain reaction test performed in a winter month when the boy was 16 years old showed a low density of B. burgdorferi sensu lato in the blood of the patient, confirmed by partial 16S rRNA (ribosomal RNA) gene sequencing. Subsequent DNA sequencing analysis presented in this report demonstrated that the spirochete isolate was a novel strain of B. burgdorferi with two homeologous 16S rRNA genes, which has never been reported in the world literature. This case report shows that direct DNA sequencing is a valuable tool for reliable molecular diagnosis of Lyme and related borrelioses, as well as for studies of the diversity of the causative agents of LD because LD patients infected by a rare or novel borrelial variant may produce an antibody pattern that can be different from the pattern characteristic of an infection caused by a typical B. burgdorferi sensu stricto strain.

  10. Lyme disease caused by Borrelia burgdorferi with two homeologous 16S rRNA genes: a case report

    Science.gov (United States)

    Lee, Sin Hang

    2016-01-01

    Lyme disease (LD), the most common tick-borne disease in North America, is believed to be caused exclusively by Borrelia burgdorferi sensu stricto and is usually diagnosed by clinical evaluation and serologic assays. As reported previously in a peer-reviewed article, a 13-year-old boy living in the Northeast of the USA was initially diagnosed with LD based on evaluation of his clinical presentations and on serologic test results. The patient was treated with a course of oral doxycycline for 28 days, and the symptoms resolved. A year later, the boy developed a series of unusual symptoms and did not attend school for 1 year. A LD specialist reviewed the case and found the serologic test band patterns nondiagnostic of LD. The boy was admitted to a psychiatric hospital. After discharge from the psychiatric hospital, a polymerase chain reaction test performed in a winter month when the boy was 16 years old showed a low density of B. burgdorferi sensu lato in the blood of the patient, confirmed by partial 16S rRNA (ribosomal RNA) gene sequencing. Subsequent DNA sequencing analysis presented in this report demonstrated that the spirochete isolate was a novel strain of B. burgdorferi with two homeologous 16S rRNA genes, which has never been reported in the world literature. This case report shows that direct DNA sequencing is a valuable tool for reliable molecular diagnosis of Lyme and related borrelioses, as well as for studies of the diversity of the causative agents of LD because LD patients infected by a rare or novel borrelial variant may produce an antibody pattern that can be different from the pattern characteristic of an infection caused by a typical B. burgdorferi sensu stricto strain. PMID:27186082

  11. Comparison of two approaches for the classification of 16S rRNA gene sequences.

    Science.gov (United States)

    Chatellier, Sonia; Mugnier, Nathalie; Allard, Françoise; Bonnaud, Bertrand; Collin, Valérie; van Belkum, Alex; Veyrieras, Jean-Baptiste; Emler, Stefan

    2014-10-01

    The use of 16S rRNA gene sequences for microbial identification in clinical microbiology is accepted widely, and requires databases and algorithms. We compared a new research database containing curated 16S rRNA gene sequences in combination with the lca (lowest common ancestor) algorithm (RDB-LCA) to a commercially available 16S rDNA Centroid approach. We used 1025 bacterial isolates characterized by biochemistry, matrix-assisted laser desorption/ionization time-of-flight MS and 16S rDNA sequencing. Nearly 80 % of isolates were identified unambiguously at the species level by both classification platforms used. The remaining isolates were mostly identified correctly at the genus level due to the limited resolution of 16S rDNA sequencing. Discrepancies between both 16S rDNA platforms were due to differences in database content and the algorithm used, and could amount to up to 10.5 %. Up to 1.4 % of the analyses were found to be inconclusive. It is important to realize that despite the overall good performance of the pipelines for analysis, some inconclusive results remain that require additional in-depth analysis performed using supplementary methods.

  12. Variability in triactinomyxon production from Tubifex tubifex populations from the same mitochondrial DNA lineage infected with Myxobolus cerebralis, the causative agent of whirling disease in salmonids

    Science.gov (United States)

    Rasmussen, C.; Zickovich, J.; Winton, J.R.; Kerans, B.L.

    2008-01-01

    Myxobolus cerebralis, the causative agent of whirling disease, infects both salmonid fish and an aquatic oligochaete, Tubifex tubifex. Although M. cerebralis has been detected in river drainages throughout the United States, disease severity among wild fish populations has been highly variable. Tubifex tubifex populations have been genetically characterized using sequences from the 16S mitochondrial DNA (mtDNA) gene, the 18S ribosomal RNA gene, the internal transcribed spacer region 1 (ITS1), and randomly amplified polymorphic DNA (RAPD). Our earlier work indicated that large differences in compatibility between the parasite and populations of T. tubifex may play a substantial role in the distribution of whirling disease and resulting mortality in different watersheds. In the present study, we examined 4 laboratory populations of T. tubifex belonging to 16S mtDNA lineage III and 1 population belonging to 16S mtDNA lineage I for triactinomyxon (TAM) production after infection with M. cerebralis myxospores. All 4 16S mtDNA lineage III populations produced TAMs, but statistically significant differences in TAM production were observed. Most individuals in the 16S mtDNA lineage III-infected populations produced TAMs. The 16S mtDNA lineage I population produced few TAMs. Further genetic characterization of the 16S mtDNA lineage III populations with RAPD markers indicated that populations producing similar levels of TAMs had more genetic similarity. ?? American Society of Parasitologists 2008.

  13. 嗜麦芽寡氧单胞菌临床株与环境株的16S rRNA基因序列及系统发育分析%16S rRNA gene and phylogenetic analysis of clinical and environmental Stenotrophomonas maltophilia isolates

    Institute of Scientific and Technical Information of China (English)

    罗玮; 毕春霞; 闫志勇; 辛晓妮; 苏维奇; 朱元祺

    2011-01-01

    Objective To compare 16S rRNA gene sequences of clinical and environmental isolates of S.mcdtophilia, construct phylogenetic tree and analyze evolutionary relationship. Methods 16S rRNA of three clinical isolates and one environmental isolate of S.maltophilia were amplified by PCR and sequenced. The 16S rRNA gene sequences of the above isolates and other 32 S.maltophilia isolates with different origins selected from GenBank were analyzed and phylogenetic tree was constructed. Results The phylogenetic analysis demonstrated most of the investigated isolates could be divided into three clusters depending on their sources. Gene sequences analysis indicated there could be key sequences on the high variable regions that were potential for distinguishing between clinical and environmental isolates. Conclusion Results of this study indicate the genotypic and phenotypic diversity of S.maltophilia. Most of the clinical and environmental S.maltophilia can be distinguished according to their 16S ribosomal DNA gene sequences.%目的:比较嗜麦芽寡氧单胞菌临床株与环境株16S rRNA基因序列,构建系统发育树,分析其进化关系.方法:对选取的3株嗜麦芽寡养单胞菌临床株和1株环境株的16S rRNA基因进行PCR扩增并测序.将上述及从GenBank中挑选出的其他32株不同来源的嗜麦芽寡养单胞菌的16S rRNA基因序列进行对比分析.并绘制系统发育树.结果:系统发育分析表明大部分菌株可根据来源分为3个簇,序列分析显示某些高度可变区可能存在可区分临床株与环境株的关键序列.结论:嗜麦芽寡养单胞菌基因型及表现型具有多样性:大部分嗜麦芽寡氧单胞菌临床株与环境株可根据16S rRNA基因序列进行鉴别.

  14. ATM-dependent E2F1 accumulation in the nucleolus is an indicator of ribosomal stress in early response to DNA damage.

    Science.gov (United States)

    Jin, Ya-Qiong; An, Guo-Shun; Ni, Ju-Hua; Li, Shu-Yan; Jia, Hong-Ti

    2014-01-01

    The nucleolus plays a major role in ribosome biogenesis. Most genotoxic agents disrupt nucleolar structure and function, which results in the stabilization/activation of p53, inducing cell cycle arrest or apoptosis. Likewise, transcription factor E2F1 as a DNA damage responsive protein also plays roles in cell cycle arrest, DNA repair, or apoptosis in response to DNA damage through transcriptional response and protein-protein interaction. Furthermore, E2F1 is known to be involved in regulating rRNA transcription. However, how E2F1 displays in coordinating DNA damage and nucleolar stress is unclear. In this study, we demonstrate that ATM-dependent E2F1 accumulation in the nucleolus is a characteristic feature of nucleolar stress in early response to DNA damage. We found that at the early stage of DNA damage, E2F1 accumulation in the nucleolus was an ATM-dependent and a common event in p53-suficient and -deficient cells. Increased nucleolar E2F1 was sequestered by the nucleolar protein p14ARF, which repressed E2F1-dependent rRNA transcription initiation, and was coupled with S phase. Our data indicate that early accumulation of E2F1 in the nucleolus is an indicator for nucleolar stress and a component of ATM pathway, which presumably buffers elevation of E2F1 in the nucleoplasm and coordinates the diversifying mechanisms of E2F1 acts in cell cycle progression and apoptosis in early response to DNA damage.

  15. Diversity and distribution of subterranean bacteria in groundwater at Oklo in Gabon, Africa, as determined by 16S rRNA gene sequencing.

    Science.gov (United States)

    Pedersen, K; Arlinger, J; Hallbeck, L; Pettersson, C

    1996-06-01

    This paper describes how ground water was sampled, DNA extracted, amplified and cloned and how information available in the ribosomal 16S rRNA gene was used for mapping diversity and distribution of subterranean bacteria in groundwater at the Bangombé site in the Oklo region. The results showed that this site was inhabited by a diversified population of bacteria. Each borehole was dominated by species that did not dominate in any of the other boreholes; a result that probably reflects documented differences in the geochemical environment. Two of the sequences obtained were identified at genus level to represent Acinetobacter and Zoogloea, but most of the 44 sequences found were only distantly related to species in the DNA database. The deepest borehole, BAX01 (105 m), had the highest number of bacteria and also total organic carbon (TOC). This borehole harboured only Proteobacteria beta group sequences while sequences related to Proteobacteria beta, gamma and delta groups and Gram-positive bacteria were found in the other four boreholes. Two of the boreholes, BAX02 (34 m) and BAX04 (10 m) had many 16S rRNA gene sequences in common and also had similar counts of bacteria, content of TOC, pH and equal conductivity, suggesting a hydraulic connection between them.

  16. 基于PCR-DGGE指纹图谱川纹笛鲷及圆白鲳消化道壁优势菌群结构比较分析%COMPARISON OF THE PREDOMINANT BACTERIAL COMMUNITY STRUCTURE IN THE GASTROINTESTINAL WALL BETWEEN LUTJANUS SEBAE AND EPHIPPUS ORBIS BASED ON 16S rDNA PCR-DGGE FINGERPRINT

    Institute of Scientific and Technical Information of China (English)

    周志刚; 石鹏君; 姚斌; 何夙旭; 苏永全; 丁兆坤

    2007-01-01

    本文采用免培养的16S rDNA 梯度凝胶电泳技术(DGGE)对集约化海水网箱养殖川纹笛鲷Lutjanus sebae及圆白鲳Ephippus orbis消化道壁优势菌群结构进行了比较分析.研究结果显示川纹笛鲷及圆白鲳消化道壁存在着大量细菌群落,对DGGE指纹图谱聚类分析表明两种鱼肠道壁及胃壁菌群组成相似度高于50%,其中二者肠道壁细菌组成相似性最高(67%),这些可能与两种鱼养殖在同一水域、摄食相同饵料相关,另外通过软件对DGGE指纹带谱相对丰度分析表明同种鱼肠道壁及胃壁具有相同最大优势菌群.同时,两种鱼消化道壁之间在细菌多样性及相对丰度上亦存在明显区别,圆白鲳消化道壁细菌多样性要高于川纹笛鲷,这可能归因于川纹笛鲷与圆白鲳在天然环境中栖息地的差异性.本研究通过首次建立不同海水鱼消化道壁16S rDNA-DGGE指纹图谱及比较分析,为澄清海水鱼消化道壁微生物区系奠定基础.

  17. Molecular Identification of Bamboo Planthoppers (Hemiptera: Delphacidae) Based on Mitochondrial 16S rDNA Gene Sequences%利用16SrDNA基因序列进行害竹飞虱(半翅目:飞虱科)的分子鉴定

    Institute of Scientific and Technical Information of China (English)

    侯晓晖; 陈祥盛

    2013-01-01

    Approximately 480 base pairs of mitochondrial 16S rDNA gene were sequenced for 15 species of Delphao idae. Of 480 bp mitochondrial 16S rDNA gene sequences, the percentage of A +T was about 77. 5% , and 190 nu-cleotide sites were substituted (about 39. 6% ). The genetic distance of outgroup and ingroup, intergenus, interspe-cies and intraspecies were 0. 317, 0. 209, 0. 132 and 0. 013 respectively. The molecular phylogenetic trees constructed by parsimony method and neighbor-joining method suggest that the ingroup and outgroup are independent evolutionary branches. The genus and species formed monophyletic groups respectively, so accuracy identification is possible through the research of sequences. These results are identical with that of morphology.%采用DNA测序技术测定了中国飞虱科5属10种15个地理种群的线粒体16S rDNA基因长约480 bp片段的序列,分析了其序列组成及变异特征.所获序列中,A+T约占77.5%,其中,190个核苷酸位点发生了变异(约占39.6%).利用MEGA 4.0软件计算遗传距离,外群与内群的遗传距离平均值(0.317)最高,内群各属间和各属内遗传距离平均值(分别为0.209和0.132)次之,而种内不同地理种群间的遗传距离平均值(0.013)最低.构建了10种飞虱科昆虫的MP和NJ分子系统树,结果显示:各属飞虱基本上形成单系群;各种飞虱各自不同地理种群均聚为一支,构成一单系群,可以很好的区分不同种类的飞虱.上述结果与形态学研究结果非常吻合.

  18. Effects of anti-C23 (nucleolin) antibody on transcription of ribosomal DNA in Chironomus salivary gland cells

    Energy Technology Data Exchange (ETDEWEB)

    Egyhazi, E.; Pigon, A. (Karolinska Institutet, Stockholm (Sweden)); Chang, Jinhong; Ghaffari, S.H.; Dreesen, T.D.; Wellman, S.E.; Case, S.T.; Olson, M.O.J. (Univ. of Mississippi Medical Center, Jackson (USA))

    1988-10-01

    Protein C23 (also called nucleolin or 100-kDa nucleolar protein) is a major nucleolar phosphoprotein involved in ribosome biogenesis. To determine the effects of protein C23 on preribosomal RNA (pre-rRNA) synthesis anti-C23 antiserum was microinjected into nuclei of Chironomus tentans salivary glands. Transcription was measured by incubation of the glands with {sup 32}P-labeled RNA precursors followed by microdissection of nucleoli, RNA extraction, and electrophoretic analyses. Injection of the anti-C23 antibody caused a 2- to 3.5-fold stimulation of {sup 32}P incorporation into 38 S pre-rRNA. No stimulation was observed in salivary glands injected with preimmune serum or antiserum preabsorbed with protein C23. The stimulatory effect was selective for pre-rRNA as indicated by the lack of stimulation of {sup 32}P incorporation into extranucleolar RNA. Injection of the antiserum produced little or no effect on pre-RNA processing as measured by the relative amounts of {sup 32}P-labeled intermediate cleavage products of pre-rRNA in stimulated versus control glands. These results suggest that protein C23 not only is involved in ribosome assembly but also plays a role in regulating the transcription of the preribosomal RNA.

  19. Sequence analysis of hypervariable regions (V3, V6) of respiratory pathogens 16S rRNA gene and exploratory study of it in liquid chip%呼吸道感染致病菌16S rRNA基因V3、V6可变区序列分析及在液态芯片中应用的探索性研究

    Institute of Scientific and Technical Information of China (English)

    陈愉生; 张伟; 王毅; 伍严安; 沈晓娜; 胡辛兰; 李鸿茹; 黄丽萍

    2014-01-01

    Objective To discuss application value of hypervariable regions (V3,V6) of respiratory pathogens 16S ribosomal RNA (rRNA) gene in liquid chip system.Methods According to respiratory pathogens 16S rRNA gene sequences from GenBank,the primers and the probes were designed and liquid chip system was established.52 DNA samples from sputum of patients with respiratory infections in Fujian provincial hospital were detected by liquid chip system.Comparing with sequencing technology,the sensitivity and specificity were analyzed.Results There were differences in hypervariable regions (V3,V6) of respiratory pathogens 16S rRNA genes.It took only 3.5 hours for liquid chip system detection.Probe of hypervariable regions V6 of Psudomonas aeruginosa 16S rRNA gene could detect > 102/μl DNA samples,threshold,the sensitivity was 100.0% and specificity was 100.0%.The sensitivity of probe of hypervariable regions V3 of Staphylococcus aureus 16S rRNA gene was 66.7%,and specificity was 98.0%.The sensitivity of probe of hypervariable regions V6 of Staphylococcus aureus 16S rRNA gene was 0.0%.Conclusions The differences in hypervariable regions(V3,V6) of respiratory pathogens 16S rRNA genes can be applied to etiology diagnosis,but not for all respiratory pathogens.%目的 探讨呼吸道感染致病菌16S rRNA基因V3、V6可变区在液态芯片系统的应用价值.方法 通过GenBank公布的呼吸道感染致病菌16S rRNA基因序列,设计并合成探针及引物,建立液态芯片检测系统,检测福建省立医院收集的52例呼吸道感染痰标本抽提的DNA,与测序结果比对,分析其灵敏度和特异度.结果 呼吸道感染致病菌16S rRNA基因V3、V6区均存在差异,应用液态芯片可在3.5h得到检测结果,铜绿假单胞菌16S rRNA V6探针,可检测浓度大于102/μl标本,检测灵敏度为100.0%,特异度为100.0%;金黄色葡萄球菌16S rRNA V3探针灵敏度为66.7%,特异度为98.0%;金黄色葡萄球菌16S rRNA V6

  20. Stenostomum cf. leucops (Platyhelminthes in Thailand: a surface observation using scanning electron microscopy and phylogenetic analysis based on 18S ribosomal DNA sequences

    Directory of Open Access Journals (Sweden)

    Arin Ngamniyom

    2016-02-01

    Full Text Available The genus Stenostomum contains small turbellaria that are widely distributed in freshwater environments worldwide. However, there are only rare reports or studies of this genus from Thailand. Therefore, the objective of this study was to report S. cf. leucops in Thailand collected from Pathum Thani Province. The worm morphology and surface topography using scanning electron microscopy were determined. Moreover, the phylogenetic tree of S. cf. leucops was analysed with 17 flatworms based on the 18S ribosomal DNA sequences. The phylogenetic relationship shared a common ancestry of Catenulida species, and S. cf. leucops displayed a monophyletic pattern within Stenostomum spp. The results of the morphological and molecular data are discussed. These results may increase the knowledge of freshwater microturbellarians in Thailand.

  1. Detection and discrimination of Loa loa, Mansonella perstans and Wuchereria bancrofti by PCR-RFLP and nested-PCR of ribosomal DNA ITS1 region.

    Science.gov (United States)

    Jiménez, Maribel; González, Luis Miguel; Carranza, Cristina; Bailo, Begoña; Pérez-Ayala, Ana; Muro, Antonio; Pérez-Arellano, José Luis; Gárate, Teresa

    2011-01-01

    The ribosomal deoxyribonucleic acid (DNA) internal transcribed spacer region (ITS1) of two filarial nematodes, Loa loa and Mansonella perstans, was amplified and further sequenced to develop an species-specific polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) protocol for the differentiation of both species from Wuchereria bancrofti, three filarial nematodes with blood circulating microfilariae. The ITS1-PCR product digested with the restriction endonuclease Ase I generated an specific diagnostic pattern for each of the three species. Moreover, three new specific nested-PCRs, targeting the ITS1 region, for differential detection of L. loa, M. perstans and W. bancrofti were developed and used when the ITS1-PCR products were insufficient for the Ase I enzymatic digestion. These filarial species-specific molecular protocols were evaluated in forty blood samples from African adult immigrants attending in the Hospital Insular of Gran Canaria, Canarias, Spain. PMID:20599994

  2. mtDNA ribosomal gene phylogeny of sea hares in the genus Aplysia (Gastropoda, Opisthobranchia, Anaspidea): Implications for comparative neurobiology

    Energy Technology Data Exchange (ETDEWEB)

    Medina, Monica; Collins, Timothy M.; Walsh, Patrick J.

    2000-08-10

    Sea hares within the genus Aplysia are important neurobiological model organisms, and as studies based on different Aplysia species appear in the literature, a phylogenetic framework has become essential. We present a phylogenetic hypothesis for this genus, based on portions of two mitochondrial genes (12S and 16S). In addition, we reconstruct the evolution of several behavioral characters of interest to neurobiologists in order to illustrate the potential benefits of a phylogeny for the genus Aplysia. These benefits include the determination of ancestral traits, the direction and timing of evolution of characters, prediction of the distribution of traits, and identification of cases of independent acquisition of traits within lineages. This last benefit may prove especially useful in understanding the linkage between behaviors and their underlying neurological basis.

  3. mtDNA ribosomal gene phylogeny of sea hares in the genus Aplysia (Gastropoda, Opisthobranchia, Anaspidea): implications for comparative neurobiology.

    Science.gov (United States)

    Medina, M; Collins, T M; Walsh, P J

    2001-01-01

    Sea hares within the genus Aplysia are important neurobiological model organisms; as more studies based on different Aplysia species are appearing in the literature, a phylogenetic framework has become essential. We present a phylogenetic hypothesis for this genus, based on portions of two mitochondrial genes (12S and 16S). In addition, we reconstruct the evolution of several behavioral characters of interest to neurobiologists to illustrate the potential benefits of a phylogeny for the genus Aplysia. These benefits include determination of ancestral traits, direction and timing of evolution of characters, prediction of the distribution of traits, and identification of cases of independent acquisition of traits within lineages. This last benefit may prove especially useful in understanding the linkage between behaviors and their underlying neurological bases. PMID:12116938

  4. 16S rRNA gene pyrosequencing reveals shift in patient faecal microbiota during high-dose chemotherapy as conditioning regimen for bone marrow transplantation.

    Science.gov (United States)

    Montassier, Emmanuel; Batard, Eric; Massart, Sébastien; Gastinne, Thomas; Carton, Thomas; Caillon, Jocelyne; Le Fresne, Sophie; Caroff, Nathalie; Hardouin, Jean Benoit; Moreau, Philippe; Potel, Gilles; Le Vacon, Françoise; de La Cochetière, Marie France

    2014-04-01

    Gastrointestinal disturbances are a side-effect frequently associated with haematological malignancies due to the intensive cytotoxic treatment given in connection with bone marrow transplantation (BMT). However, intestinal microbiota changes during chemotherapy remain poorly described, probably due to the use of culture-based and low-resolution molecular methods in previous studies. The objective of our study was to apply a next generation DNA sequencing technology to analyse chemotherapy-induced changes in faecal microbiota. We included eight patients with non-Hodgkin's lymphoma undergoing one course of BMT conditioning chemotherapy. We collected a prechemotherapy faecal sample, the day before chemotherapy was initiated, and a postchemotherapy sample, collected 1 week after the initiation of chemotherapy. Total DNA was extracted from faecal samples, denaturing high-performance liquid chromatography based on amplification of the V6 to V8 region of the 16S ribosomal RNA (rRNA) gene, and 454-pyrosequencing of the 16 S rRNA gene, using PCR primers targeting the V5 and V6 hypervariable 16S rRNA gene regions were performed. Raw sequence data were screened, trimmed, and filtered using the QIIME pipeline. We observed a steep reduction in alpha diversity and significant differences in the composition of the intestinal microbiota in response to chemotherapy. Chemotherapy was associated with a drastic drop in Faecalibacterium and accompanied by an increase of Escherichia. The chemotherapy-induced shift in the intestinal microbiota could induce severe side effects in immunocompromised cancer patients. Our study is a first step in identifying patients at risk for gastrointestinal disturbances and to promote strategies to prevent this drastic shift in intestinal microbiota. PMID:24402367

  5. 16S rRNA gene-based metagenomic analysis reveals differences in bacteria-derived extracellular vesicles in the urine of pregnant and non-pregnant women.

    Science.gov (United States)

    Yoo, Jae Young; Rho, Mina; You, Young-Ah; Kwon, Eun Jin; Kim, Min-Hye; Kym, Sungmin; Jee, Young-Koo; Kim, Yoon-Keun; Kim, Young Ju

    2016-02-05

    Recent evidence has indicated that bacteria-derived extracellular vesicles (EVs) are important for host-microbe communication. The aims of the present study were to evaluate whether bacteria-derived EVs are excreted via the urinary tract and to compare the composition of bacteria-derived EVs in the urine of pregnant and non-pregnant women. Seventy-three non-pregnant and seventy-four pregnant women were enrolled from Dankook University and Ewha Womans University hospitals. DNA was extracted from urine EVs after EV isolation using the differential centrifugation method. 16S ribosomal RNA (16S rRNA) gene sequencing was performed using high-throughput 454 pyrosequencing after amplification of the V1-V3 region of the 16S rDNA. The composition of 13 taxa differed significantly between the pregnant and non-pregnant women. At the genus level, Bacillus spp. EVs were more significantly enriched in the urine of the pregnant women than in that of the non-pregnant women (45.61% vs 0.12%, respectively). However, Pseudomonas spp. EVs were more dominant in non-pregnant women than in pregnant women (13.2% vs 4.09%, respectively). Regarding the compositional difference between pregnant women with normal and preterm delivery, EVs derived from Ureaplasma spp. and the family Veillonellaceae (including Megasphaera spp.) were more abundant in the urine of preterm-delivered women than in that of women with normal deliveries. Taken together, these data showed that Bacillus spp. EVs predominate in the urine of pregnant women, whereas Pseudomonas spp. EVs predominate in the urine of non-pregnant women; this suggests that Bacillus spp. EVs might have an important role in the maintenance of pregnancy.

  6. 16S rRNA gene-based metagenomic analysis reveals differences in bacteria-derived extracellular vesicles in the urine of pregnant and non-pregnant women

    Science.gov (United States)

    Yoo, Jae Young; Rho, Mina; You, Young-Ah; Kwon, Eun Jin; Kim, Min-Hye; Kym, Sungmin; Jee, Young-Koo; Kim, Yoon-Keun; Kim, Young Ju

    2016-01-01

    Recent evidence has indicated that bacteria-derived extracellular vesicles (EVs) are important for host–microbe communication. The aims of the present study were to evaluate whether bacteria-derived EVs are excreted via the urinary tract and to compare the composition of bacteria-derived EVs in the urine of pregnant and non-pregnant women. Seventy-three non-pregnant and seventy-four pregnant women were enrolled from Dankook University and Ewha Womans University hospitals. DNA was extracted from urine EVs after EV isolation using the differential centrifugation method. 16S ribosomal RNA (16S rRNA) gene sequencing was performed using high-throughput 454 pyrosequencing after amplification of the V1–V3 region of the 16S rDNA. The composition of 13 taxa differed significantly between the pregnant and non-pregnant women. At the genus level, Bacillus spp. EVs were more significantly enriched in the urine of the pregnant women than in that of the non-pregnant women (45.61% vs 0.12%, respectively). However, Pseudomonas spp. EVs were more dominant in non-pregnant women than in pregnant women (13.2% vs 4.09%, respectively). Regarding the compositional difference between pregnant women with normal and preterm delivery, EVs derived from Ureaplasma spp. and the family Veillonellaceae (including Megasphaera spp.) were more abundant in the urine of preterm-delivered women than in that of women with normal deliveries. Taken together, these data showed that Bacillus spp. EVs predominate in the urine of pregnant women, whereas Pseudomonas spp. EVs predominate in the urine of non-pregnant women; this suggests that Bacillus spp. EVs might have an important role in the maintenance of pregnancy. PMID:26846451

  7. 16S rRNA gene-based metagenomic analysis reveals differences in bacteria-derived extracellular vesicles in the urine of pregnant and non-pregnant women.

    Science.gov (United States)

    Yoo, Jae Young; Rho, Mina; You, Young-Ah; Kwon, Eun Jin; Kim, Min-Hye; Kym, Sungmin; Jee, Young-Koo; Kim, Yoon-Keun; Kim, Young Ju

    2016-01-01

    Recent evidence has indicated that bacteria-derived extracellular vesicles (EVs) are important for host-microbe communication. The aims of the present study were to evaluate whether bacteria-derived EVs are excreted via the urinary tract and to compare the composition of bacteria-derived EVs in the urine of pregnant and non-pregnant women. Seventy-three non-pregnant and seventy-four pregnant women were enrolled from Dankook University and Ewha Womans University hospitals. DNA was extracted from urine EVs after EV isolation using the differential centrifugation method. 16S ribosomal RNA (16S rRNA) gene sequencing was performed using high-throughput 454 pyrosequencing after amplification of the V1-V3 region of the 16S rDNA. The composition of 13 taxa differed significantly between the pregnant and non-pregnant women. At the genus level, Bacillus spp. EVs were more significantly enriched in the urine of the pregnant women than in that of the non-pregnant women (45.61% vs 0.12%, respectively). However, Pseudomonas spp. EVs were more dominant in non-pregnant women than in pregnant women (13.2% vs 4.09%, respectively). Regarding the compositional difference between pregnant women with normal and preterm delivery, EVs derived from Ureaplasma spp. and the family Veillonellaceae (including Megasphaera spp.) were more abundant in the urine of preterm-delivered women than in that of women with normal deliveries. Taken together, these data showed that Bacillus spp. EVs predominate in the urine of pregnant women, whereas Pseudomonas spp. EVs predominate in the urine of non-pregnant women; this suggests that Bacillus spp. EVs might have an important role in the maintenance of pregnancy. PMID:26846451

  8. IDENTIFICATION OF ACTIVE BACTERIAL COMMUNITIES IN A MODEL DRINKING WATER BIOFILM SYSTEM USING 16S RRNA-BASED CLONE LIBRARIES

    Science.gov (United States)

    Recent phylogenetic studies have used DNA as the target molecule for the development of environmental 16S rDNA clone libraries. As DNA may persist in the environment, DNA-based libraries cannot be used to identify metabolically active bacteria in water systems. In this study, a...

  9. TaxCollector: Modifying Current 16S rRNA Databases for the Rapid Classification at Six Taxonomic Levels

    Directory of Open Access Journals (Sweden)

    Eric W. Triplett

    2010-07-01

    Full Text Available The high level of conservation of 16S ribosomal RNA gene (16S rRNA in all Prokaryotes makes this gene an ideal tool for the rapid identification and classification of these microorganisms. Databases such as the Ribosomal Database Project II (RDP-II and the Greengenes Project offer access to sets of ribosomal RNA sequence databases useful in identification of microbes in a culture-independent analysis of microbial communities. However, these databases do not contain all of the taxonomic levels attached to the published names of the bacterial and archaeal sequences. TaxCollector is a set of scripts developed in Python language that attaches taxonomic information to all 16S rRNA sequences in the RDP-II and Greengenes databases. These modified databases are referred to as TaxCollector databases, which when used in conjunction with BLAST allow for rapid classification of sequences from any environmental or clinical source at six different taxonomic levels, from domain to species. The TaxCollector database prepared from the RDP-II database is an important component of a new 16S rRNA pipeline called PANGEA. The usefulness of TaxCollector databases is demonstrated with two very different datasets obtained using samples from a clinical setting and an agricultural soil. The six TaxCollector scripts are freely available on http://taxcollector.sourceforge.net and on http://www.microgator.org.

  10. Surface topography of the Bacillus stearothermophilus ribosome

    International Nuclear Information System (INIS)

    The surface topography of the intact 70S ribosome and free 30S and 50S subunits from Bacillus stearothermophilus strain 2,184 was investigated by lactoperoxidase-catalyzed iodination. Two-dimensional polyacrylamide gel electrophoresis was employed to separate ribosomal proteins for analysis of their reactivity. Free 50S subunits incorporated about 18% more 125I than did 50S subunits derived from 70S ribosomes, whereas free 30S subunits and 30S subunits derived from 70S ribosomes incorporated similar amounts of 125I. Iodinated 70S ribosomes and subunits retained 62-78% of the protein synthesis activity of untreated particles and sedimentation profiles showed no gross conformational changes due to iodination. The proteins most reactive to enzymatic iodination were S4, S7, S10 and Sa of the small subunit and L2, L4, L5/9, L6 and L36 of the large subunit. Proteins S2, S3, S7, S13, Sa, L5/9, L10, L11 and L24/25 were labeled substantially more in the free subunits than in the 70S ribosome. Other proteins, including S5, S9, S12, S15/16, S18 and L36 were more extensively iodinated in the 70S ribosome than in the free subunits. The locations of tyrosine residues in some homologus ribosomal proteins from B. stearothermophilus and E. coli are compared. (orig.)

  11. The Characterization of Novel Tissue Microbiota Using an Optimized 16S Metagenomic Sequencing Pipeline.

    Directory of Open Access Journals (Sweden)

    Jérôme Lluch

    Full Text Available Substantial progress in high-throughput metagenomic sequencing methodologies has enabled the characterisation of bacteria from various origins (for example gut and skin. However, the recently-discovered bacterial microbiota present within animal internal tissues has remained unexplored due to technical difficulties associated with these challenging samples.We have optimized a specific 16S rDNA-targeted metagenomics sequencing (16S metabarcoding pipeline based on the Illumina MiSeq technology for the analysis of bacterial DNA in human and animal tissues. This was successfully achieved in various mouse tissues despite the high abundance of eukaryotic DNA and PCR inhibitors in these samples. We extensively tested this pipeline on mock communities, negative controls, positive controls and tissues and demonstrated the presence of novel tissue specific bacterial DNA profiles in a variety of organs (including brain, muscle, adipose tissue, liver and heart.The high throughput and excellent reproducibility of the method ensured exhaustive and precise coverage of the 16S rDNA bacterial variants present in mouse tissues. This optimized 16S metagenomic sequencing pipeline will allow the scientific community to catalogue the bacterial DNA profiles of different tissues and will provide a database to analyse host/bacterial interactions in relation to homeostasis and disease.

  12. Veronica: Chemical characters for the support of phylogenetic relationships based on nuclear ribosomal and plastid DNA sequence data

    DEFF Research Database (Denmark)

    Albach, Dirk C.; Jensen, Søren Rosendal; Özgökce, Fevzi;

    2005-01-01

    Molecular phylogenetic analyses have revealed many relationships in Veronica (Plantaginaceae) never anticipated before. However, phytochemical characters show good congruence with DNA-based analyses. We have analysed a combined data set of 49 species and subspecies derived from the nuclear...

  13. RiboFR-Seq: a novel approach to linking 16S rRNA amplicon profiles to metagenomes.

    Science.gov (United States)

    Zhang, Yanming; Ji, Peifeng; Wang, Jinfeng; Zhao, Fangqing

    2016-06-01

    16S rRNA amplicon analysis and shotgun metagenome sequencing are two main culture-independent strategies to explore the genetic landscape of various microbial communities. Recently, numerous studies have employed these two approaches together, but downstream data analyses were performed separately, which always generated incongruent or conflict signals on both taxonomic and functional classifications. Here we propose a novel approach, RiboFR-Seq (Ribosomal RNA gene flanking region sequencing), for capturing both ribosomal RNA variable regions and their flanking protein-coding genes simultaneously. Through extensive testing on clonal bacterial strain, salivary microbiome and bacterial epibionts of marine kelp, we demonstrated that RiboFR-Seq could detect the vast majority of bacteria not only in well-studied microbiomes but also in novel communities with limited reference genomes. Combined with classical amplicon sequencing and shotgun metagenome sequencing, RiboFR-Seq can link the annotations of 16S rRNA and metagenomic contigs to make a consensus classification. By recognizing almost all 16S rRNA copies, the RiboFR-seq approach can effectively reduce the taxonomic abundance bias resulted from 16S rRNA copy number variation. We believe that RiboFR-Seq, which provides an integrated view of 16S rRNA profiles and metagenomes, will help us better understand diverse microbial communities. PMID:26984526

  14. The DNA virus white spot syndrome virus uses an internal ribosome entry site for translation of the highly expressed nonstructural protein ICP35.

    Science.gov (United States)

    Kang, Shih-Ting; Wang, Han-Ching; Yang, Yi-Ting; Kou, Guang-Hsiung; Lo, Chu-Fang

    2013-12-01

    Although shrimp white spot syndrome virus (WSSV) is a large double-stranded DNA virus (∼300 kbp), it expresses many polycistronic mRNAs that are likely to use internal ribosome entry site (IRES) elements for translation. A polycistronic mRNA encodes the gene of the highly expressed nonstructural protein ICP35, and here we use a dual-luciferase assay to demonstrate that this protein is translated cap independently by an IRES element located in the 5' untranslated region of icp35. A deletion analysis of this region showed that IRES activity was due to stem-loops VII and VIII. A promoterless assay, a reverse transcription-PCR together with quantitative real-time PCR analysis, and a stable stem-loop insertion upstream of the Renilla luciferase open reading frame were used, respectively, to rule out the possibility that cryptic promoter activity, abnormal splicing, or read-through was contributing to the IRES activity. In addition, a Northern blot analysis was used to confirm that only a single bicistronic mRNA was expressed. The importance of ICP35 to viral replication was demonstrated in a double-stranded RNA (dsRNA) interference knockdown experiment in which the mortality of the icp35 dsRNA group was significantly reduced. Tunicamycin was used to show that the α subunit of eukaryotic initiation factor 2 is required for icp35 IRES activity. We also found that the intercalating drug quinacrine significantly inhibited icp35 IRES activity in vitro and reduced the mortality rate and viral copy number in WSSV-challenged shrimp. Lastly, in Sf9 insect cells, we found that knockdown of the gene for the Spodoptera frugiperda 40S ribosomal protein RPS10 decreased icp35 IRES-regulated firefly luciferase activity but had no effect on cap-dependent translation. PMID:24089551

  15. Isolation and phylogenetic relationship of orchid-mycorrhiza from Spathoglottis plicata of Papua using mitochondrial ribosomal large subunit (mt-Ls DNA

    Directory of Open Access Journals (Sweden)

    SUPENI SUFAATI

    2012-04-01

    Full Text Available Sufaati S, Agustini V, Suharno. 2012. Isolation and phylogenetic relationship of orchid-mycorrhiza from Spathoglottis plicata of Papua using mitochondrial ribosomal large subunit (mt-Ls DNA. Biodiversitas 13: 59-64. All terrestrial mycorrhiza have mutual symbiotic with mycorrhizal fungi in order to gain nutrient from surrounding environment. This study was done to isolate and to identify mycorrhiza orchid that associates with Spathoglottis plicata and were collected from Cagar Alam Pegunungan Cycloops (CAPC, Jayapura. Isolation of mycorrhizal orchid came after the modified method of Manoch and Lohsomboon (1991. The result showed that based on the morphological characteristic, there was presumably 14 isolations. However, only 2 isolations have been known, namely Rhizoctonia sp. and Tulasnella sp., while the rest were not identified yet. Among them, the DNA of the 11 isolations were able to be extracted for further analysis. The constructed phylogenetic tree performed that those species could be grouped into 4 major clusters. Two species, Rhizoctonia sp. and Tulasnella sp. were in different clusters.

  16. Characterization of Trichuris trichiura from humans and T. suis from pigs in China using internal transcribed spacers of nuclear ribosomal DNA.

    Science.gov (United States)

    Liu, G H; Zhou, W; Nisbet, A J; Xu, M J; Zhou, D H; Zhao, G H; Wang, S K; Song, H Q; Lin, R Q; Zhu, X Q

    2014-03-01

    Trichuris trichiura and Trichuris suis parasitize (at the adult stage) the caeca of humans and pigs, respectively, causing trichuriasis. Despite these parasites being of human and animal health significance, causing considerable socio-economic losses globally, little is known of the molecular characteristics of T. trichiura and T. suis from China. In the present study, the entire first and second internal transcribed spacer (ITS-1 and ITS-2) regions of nuclear ribosomal DNA (rDNA) of T. trichiura and T. suis from China were amplified by polymerase chain reaction (PCR), the representative amplicons were cloned and sequenced, and sequence variation in the ITS rDNA was examined. The ITS rDNA sequences for the T. trichiura and T. suis samples were 1222-1267 bp and 1339-1353 bp in length, respectively. Sequence analysis revealed that the ITS-1, 5.8S and ITS-2 rDNAs of both whipworms were 600-627 bp and 655-661 bp, 154 bp, and 468-486 bp and 530-538 bp in size, respectively. Sequence variation in ITS rDNA within and among T. trichiura and T. suis was examined. Excluding nucleotide variations in the simple sequence repeats, the intra-species sequence variation in the ITS-1 was 0.2-1.7% within T. trichiura, and 0-1.5% within T. suis. For ITS-2 rDNA, the intra-species sequence variation was 0-1.3% within T. trichiura and 0.2-1.7% within T. suis. The inter-species sequence differences between the two whipworms were 60.7-65.3% for ITS-1 and 59.3-61.5% for ITS-2. These results demonstrated that the ITS rDNA sequences provide additional genetic markers for the characterization and differentiation of the two whipworms. These data should be useful for studying the epidemiology and population genetics of T. trichiura and T. suis, as well as for the diagnosis of trichuriasis in humans and pigs.

  17. Direct 16S rRNA-seq from bacterial communities: a PCR-independent approach to simultaneously assess microbial diversity and functional activity potential of each taxon

    Science.gov (United States)

    Rosselli, Riccardo; Romoli, Ottavia; Vitulo, Nicola; Vezzi, Alessandro; Campanaro, Stefano; de Pascale, Fabio; Schiavon, Riccardo; Tiarca, Maurizio; Poletto, Fabio; Concheri, Giuseppe; Valle, Giorgio; Squartini, Andrea

    2016-01-01

    The analysis of environmental microbial communities has largely relied on a PCR-dependent amplification of genes entailing species identity as 16S rRNA. This approach is susceptible to biases depending on the level of primer matching in different species. Moreover, possible yet-to-discover taxa whose rRNA could differ enough from known ones would not be revealed. DNA-based methods moreover do not provide information on the actual physiological relevance of each taxon within an environment and are affected by the variable number of rRNA operons in different genomes. To overcome these drawbacks we propose an approach of direct sequencing of 16S ribosomal RNA without any primer- or PCR-dependent step. The method was tested on a microbial community developing in an anammox bioreactor sampled at different time-points. A conventional PCR-based amplicon pyrosequencing was run in parallel. The community resulting from direct rRNA sequencing was highly consistent with the known biochemical processes operative in the reactor. As direct rRNA-seq is based not only on taxon abundance but also on physiological activity, no comparison between its results and those from PCR-based approaches can be applied. The novel principle is in this respect proposed not as an alternative but rather as a complementary methodology in microbial community studies. PMID:27577787

  18. Direct 16S rRNA-seq from bacterial communities: a PCR-independent approach to simultaneously assess microbial diversity and functional activity potential of each taxon.

    Science.gov (United States)

    Rosselli, Riccardo; Romoli, Ottavia; Vitulo, Nicola; Vezzi, Alessandro; Campanaro, Stefano; de Pascale, Fabio; Schiavon, Riccardo; Tiarca, Maurizio; Poletto, Fabio; Concheri, Giuseppe; Valle, Giorgio; Squartini, Andrea

    2016-01-01

    The analysis of environmental microbial communities has largely relied on a PCR-dependent amplification of genes entailing species identity as 16S rRNA. This approach is susceptible to biases depending on the level of primer matching in different species. Moreover, possible yet-to-discover taxa whose rRNA could differ enough from known ones would not be revealed. DNA-based methods moreover do not provide information on the actual physiological relevance of each taxon within an environment and are affected by the variable number of rRNA operons in different genomes. To overcome these drawbacks we propose an approach of direct sequencing of 16S ribosomal RNA without any primer- or PCR-dependent step. The method was tested on a microbial community developing in an anammox bioreactor sampled at different time-points. A conventional PCR-based amplicon pyrosequencing was run in parallel. The community resulting from direct rRNA sequencing was highly consistent with the known biochemical processes operative in the reactor. As direct rRNA-seq is based not only on taxon abundance but also on physiological activity, no comparison between its results and those from PCR-based approaches can be applied. The novel principle is in this respect proposed not as an alternative but rather as a complementary methodology in microbial community studies. PMID:27577787

  19. Genetic diversity and molecular evolution of Naga King Chili inferred from internal transcribed spacer sequence of nuclear ribosomal DNA.

    Science.gov (United States)

    Kehie, Mechuselie; Kumaria, Suman; Devi, Khumuckcham Sangeeta; Tandon, Pramod

    2016-02-01

    Sequences of the Internal Transcribed Spacer (ITS1-5.8S-ITS2) of nuclear ribosomal DNAs were explored to study the genetic diversity and molecular evolution of Naga King Chili. Our study indicated the occurrence of nucleotide polymorphism and haplotypic diversity in the ITS regions. The present study demonstrated that the variability of ITS1 with respect to nucleotide diversity and sequence polymorphism exceeded that of ITS2. Sequence analysis of 5.8S gene revealed a much conserved region in all the accessions of Naga King Chili. However, strong phylogenetic information of this species is the distinct 13 bp deletion in the 5.8S gene which discriminated Naga King Chili from the rest of the Capsicum sp. Neutrality test results implied a neutral variation, and population seems to be evolving at drift-mutation equilibrium and free from directed selection pressure. Furthermore, mismatch analysis showed multimodal curve indicating a demographic equilibrium. Phylogenetic relationships revealed by Median Joining Network (MJN) analysis denoted a clear discrimination of Naga King Chili from its closest sister species (Capsicum chinense and Capsicum frutescens). The absence of star-like network of haplotypes suggested an ancient population expansion of this chili. PMID:26862481

  20. Resolution of phylogenetic relationships of the major subfamilies of the Delphacidae (Homoptera: Fulgoroidea) using the mitochondrial ribosomal DNA

    Institute of Scientific and Technical Information of China (English)

    EDDY DIJKSTRA; MICHEL A. SLOTMAN; RORY J. POST

    2006-01-01

    Delphacid relationships from the genus level to the subfamily have been completely resolved (among those taxa examined) using sequence data from the 3' end of the 12S gene. Monophyly of the non-asiracine subfamilies was strongly supported and the asiracine Ugyops was placed in the most basal position of the tree. Support levels for monophyly of the Delphacini increased after weighting transversions more heavily than transitions and after removing the cixiid outgroup from the dataset. Among the Delphacini,Conomelus and Megamelus were more closely related to each other than either was to Chloriona. These results are in agreement with the tree based on morphological characters. However, in contrast to morphological data our results strongly supported a sister group relationship between the Stenocraninae and the Kelisiinae. Although the 12S gene fragment gave some information about the species relationships within Chloriona, neither this fragment nor the 5' end of the 16S gene appear to be very useful for this level. Molecular evolutionary patterns provided evidence that there has been a shift in base composition from T to A during the early evolution of the non-Asiracinae. The non-Asiracinae also had comparatively fast substitution rates and these two observations are possibly correlated. In the 'modern' delphacid Chloriona, the AT content was comparatively low in regions free of constraints but this was not the case for 'non-modern' delphacids. The tRNA for valine has been translocated elsewhere, probably before the Delphacidae and Cixiidae diverged from each other.

  1. PCR Conditions for 16S Primers for Analysis of Microbes in the Colon of Rats.

    Science.gov (United States)

    Guillen, I A; Camacho, H; Tuero, A D; Bacardí, D; Palenzuela, D O; Aguilera, A; Silva, J A; Estrada, R; Gell, O; Suárez, J; Ancizar, J; Brown, E; Colarte, A B; Castro, J; Novoa, L I

    2016-09-01

    The study of the composition of the intestinal flora is important to the health of the host, playing a key role in maintaining intestinal homeostasis and the evolution of the immune system. For these studies, various universal primers of the 16S rDNA gene are used in microbial taxonomy. Here, we report an evaluation of 5 universal primers to explore the presence of microbial DNA in colon biopsies preserved in RNAlater solution. The DNA extracted was used for the amplification of PCR products containing the variable (V) regions of the microbial 16S rDNA gene. The PCR products were studied by restriction fragment length polymorphism (RFLP) analysis and DNA sequence, whose percent of homology with microbial sequences reported in GenBank was verified using bioinformatics tools. The presence of microbes in the colon of rats was quantified by the quantitative PCR (qPCR) technique. We obtained microbial DNA from rat, useful for PCR analysis with the universal primers for the bacteria 16S rDNA. The sequences of PCR products obtained from a colon biopsy of the animal showed homology with the classes bacilli (Lactobacillus spp) and proteobacteria, normally represented in the colon of rats. The proposed methodology allowed the attainment of DNA of bacteria with the quality and integrity for use in qPCR, sequencing, and PCR-RFLP analysis. The selected universal primers provided knowledge of the abundance of microorganisms and the formation of a preliminary test of bacterial diversity in rat colon biopsies.

  2. Development of a dual-internal-reference technique to improve accuracy when determining bacterial 16S rRNA:16S rRNA gene ratio with application to Escherichia coli liquid and aerosol samples.

    Science.gov (United States)

    Zhen, Huajun; Krumins, Valdis; Fennell, Donna E; Mainelis, Gediminas

    2015-10-01

    Accurate enumeration of rRNA content in microbial cells, e.g. by using the 16S rRNA:16S rRNA gene ratio, is critical to properly understand its relationship to microbial activities. However, few studies have considered possible methodological artifacts that may contribute to the variability of rRNA analysis results. In this study, a technique utilizing genomic DNA and 16S rRNA from an exogenous species (Pseudomonas fluorescens) as dual internal references was developed to improve accuracy when determining the 16S rRNA:16S rRNA gene ratio of a target organism, Escherichia coli. This technique was able to adequately control the variability in sample processing and analysis procedures due to nucleic acid (DNA and RNA) losses, inefficient reverse transcription of RNA, and inefficient PCR amplification. The measured 16S rRNA:16S rRNA gene ratio of E. coli increased by 2-3 fold when E. coli 16S rRNA gene and 16S rRNA quantities were normalized to the sample-specific fractional recoveries of reference (P. fluorescens) 16S rRNA gene and 16S rRNA, respectively. In addition, the intra-sample variation of this ratio, represented by coefficients of variation from replicate samples, decreased significantly after normalization. This technique was applied to investigate the temporal variation of 16S rRNA:16S rRNA gene ratio of E. coli during its non-steady-state growth in a complex liquid medium, and to E. coli aerosols when exposed to particle-free air after their collection on a filter. The 16S rRNA:16S rRNA gene ratio of E. coli increased significantly during its early exponential phase of growth; when E. coli aerosols were exposed to extended filtration stress after sample collection, the ratio also increased. In contrast, no significant temporal trend in E. coli 16S rRNA:16S rRNA gene ratio was observed when the determined ratios were not normalized based on the recoveries of dual references. The developed technique could be widely applied in studies of relationship between

  3. Introducing W.A.T.E.R.S.: a Workflow for the Alignment, Taxonomy, and Ecology of Ribosomal Sequences

    Directory of Open Access Journals (Sweden)

    Ludäscher Bertram

    2010-06-01

    Full Text Available Abstract Background For more than two decades microbiologists have used a highly conserved microbial gene as a phylogenetic marker for bacteria and archaea. The small-subunit ribosomal RNA gene, also known as 16 S rRNA, is encoded by ribosomal DNA, 16 S rDNA, and has provided a powerful comparative tool to microbial ecologists. Over time, the microbial ecology field has matured from small-scale studies in a select number of environments to massive collections of sequence data that are paired with dozens of corresponding collection variables. As the complexity of data and tool sets have grown, the need for flexible automation and maintenance of the core processes of 16 S rDNA sequence analysis has increased correspondingly. Results We present WATERS, an integrated approach for 16 S rDNA analysis that bundles a suite of publicly available 16 S rDNA analysis software tools into a single software package. The "toolkit" includes sequence alignment, chimera removal, OTU determination, taxonomy assignment, phylogentic tree construction as well as a host of ecological analysis and visualization tools. WATERS employs a flexible, collection-oriented 'workflow' approach using the open-source Kepler system as a platform. Conclusions By packaging available software tools into a single automated workflow, WATERS simplifies 16 S rDNA analyses, especially for those without specialized bioinformatics, programming expertise. In addition, WATERS, like some of the newer comprehensive rRNA analysis tools, allows researchers to minimize the time dedicated to carrying out tedious informatics steps and to focus their attention instead on the biological interpretation of the results. One advantage of WATERS over other comprehensive tools is that the use of the Kepler workflow system facilitates result interpretation and reproducibility via a data provenance sub-system. Furthermore, new "actors" can be added to the workflow as desired and we see WATERS as an initial seed

  4. Cisplatin Targeting of Bacterial Ribosomal RNA Hairpins

    Directory of Open Access Journals (Sweden)

    Gayani N. P. Dedduwa-Mudalige

    2015-09-01

    Full Text Available Cisplatin is a clinically important chemotherapeutic agent known to target purine bases in nucleic acids. In addition to major deoxyribonucleic acid (DNA intrastrand cross-links, cisplatin also forms stable adducts with many types of ribonucleic acid (RNA including siRNA, spliceosomal RNAs, tRNA, and rRNA. All of these RNAs play vital roles in the cell, such as catalysis of protein synthesis by rRNA, and therefore serve as potential drug targets. This work focused on platination of two highly conserved RNA hairpins from E. coli ribosomes, namely pseudouridine-modified helix 69 from 23S rRNA and the 790 loop of helix 24 from 16S rRNA. RNase T1 probing, MALDI mass spectrometry, and dimethyl sulfate mapping revealed platination at GpG sites. Chemical probing results also showed platination-induced RNA structural changes. These findings reveal solvent and structural accessibility of sites within bacterial RNA secondary structures that are functionally significant and therefore viable targets for cisplatin as well as other classes of small molecules. Identifying target preferences at the nucleotide level, as well as determining cisplatin-induced RNA conformational changes, is important for the design of more potent drug molecules. Furthermore, the knowledge gained through studies of RNA-targeting by cisplatin is applicable to a broad range of organisms from bacteria to human.

  5. 16S rRNA甲基化介导的氨基糖苷类耐药%Resistance mechanism against aminoglycosides mediated by 16S rRNA methylation

    Institute of Scientific and Technical Information of China (English)

    张晓文

    2012-01-01

    Aminoglycosid.es have been used for the treatment of a broad range of life -threatening Gram-positive and Grarrmeg-ative bacterial infections. These agents bind to the A site of the 16S rRNA of the bacterial 30S ribosomal subunit and subsequently block its growth through interference with its protein synthesis . 16S rRNA methylation is capable of conferring an extraordinarily high level of resistance against most of the clinically important aminoglycosides . Previous research has shown that this phenomenon is media -ted by some 16S rRNA methylase. Because of the clinical importance of these enzymes , further global dissemination of 16S rRNA methylase genes among pathogenic bacilli will be a cause of great concern in the near future . This article presents an overview on the action mechanism, origin, classification and genetic environment of 16S rRNA methylase.%氨基糖苷类抗生素在治疗革兰阳性和阴性细菌引起的感染中起着重要的作用,可通过与细菌30S核糖体亚基的16S rRNA的A位点结合而阻碍蛋白质的合成.16S rRNA甲基化作用可导致细菌对氨基糖苷类药物高水平耐药,大量研究显示这一现象是由一类16S rRNA甲基化酶所介导的.由于16S rRNA甲基化酶在临床上的重要性,为引起医务人员的重视,文中将从此类酶的作用机制、起源、分类以及基因环境等方面作一综述.

  6. Bacterial metabarcoding by 16S rRNA gene ion torrent amplicon sequencing.

    Science.gov (United States)

    Fantini, Elio; Gianese, Giulio; Giuliano, Giovanni; Fiore, Alessia

    2015-01-01

    Ion Torrent is a next generation sequencing technology based on the detection of hydrogen ions produced during DNA chain elongation; this technology allows analyzing and characterizing genomes, genes, and species. Here, we describe an Ion Torrent procedure applied to the metagenomic analysis of 16S rRNA gene amplicons to study the bacterial diversity in food and environmental samples. PMID:25343859

  7. Effects of 16S rRNA gene mutations on tetracycline resistance in Helicobacter pylori

    NARCIS (Netherlands)

    M.M. Gerrits (Monique); M. Berning; A.H.M. van Vliet (Arnoud); E.J. Kuipers (Ernst); J.G. Kusters (Johannes)

    2003-01-01

    textabstractThe triple-base-pair 16S rDNA mutation AGA(926-928)-->TTC mediates high-level tetracycline resistance in Helicobacter pylori. In contrast, single- and double-base-pair mutations mediated only low-level tetracycline resistance and decreased growth rates in the presence o

  8. Bacterial metabarcoding by 16S rRNA gene ion torrent amplicon sequencing.

    Science.gov (United States)

    Fantini, Elio; Gianese, Giulio; Giuliano, Giovanni; Fiore, Alessia

    2015-01-01

    Ion Torrent is a next generation sequencing technology based on the detection of hydrogen ions produced during DNA chain elongation; this technology allows analyzing and characterizing genomes, genes, and species. Here, we describe an Ion Torrent procedure applied to the metagenomic analysis of 16S rRNA gene amplicons to study the bacterial diversity in food and environmental samples.

  9. 松材线虫rDNA的测序和PCR—SSCP分析%SEQUENCING AND PCR-SSCP ANALYSIS OF RIBOSOMAL DNA OF Bursaphelenchus NEMATODES

    Institute of Scientific and Technical Information of China (English)

    张立海; 廖金铃; 冯志新

    2001-01-01

    To overcome limitations in the morphological identification of Bursaphelenchus species, a molecular approach was used. The internal transcribed spacer 1 (ITS1) of the nuclear ribosomal DNA (rDNA) region was amplified and sequenced. A pairwise comparison of this sequence data revealed that the differences in the ITS1 region (approximately 308 bp) between four B. xylophilus isolates were slight (only 1 bp), but there are marked differences (up to 7 bp) in this region between the B. mucronatus isolates from China (Guangdong) and France.The data also revealed that the differences in the ITS1 region between the two Bursaphelenchus species range from 32-39 bp. Based on these data, the method of extracting the genomic DNA of the individual pinewood nematode and PCR-SSCP (single-strand conformation polymorphism) analysis were employed for the unequivocal differentiation of the Bursaphelenchus variant from B. xylophilus and B. mucronatus. These methods should provide a valuable tool for sensitive and accurate identification of individual worm of B. xylophilus.%本文为克服形态鉴定的不足,用分子生物学的方法鉴别松材线虫。线虫核糖体DNA(rDNA)的内部转录间隔区(ITS1)区(约308 bp)的测序结果显示:松材线虫种内区别很小,不超过1 bp;拟松材线虫种内区别较大,最大达7 bp;这2种线虫的种间区别为32~39 bp。根据以上测序结果,本文结合单条线虫DNA的提取技术,对14个松材线虫和拟松材线虫样本进行了单链构象多态性(PCR—SSCP)分析,结果表明PCR-SSCP分析技术可明确区分这2种线虫,该技术可为单条松材线虫的鉴定提供一套灵敏而可靠的方法。

  10. Phylogenetic utility of ribosomal genes for reconstructing the phylogeny of five Chinese satyrine tribes (Lepidoptera, Nymphalidae

    Directory of Open Access Journals (Sweden)

    Mingsheng Yang

    2015-03-01

    Full Text Available Satyrinae is one of twelve subfamilies of the butterfly family Nymphalidae, which currently includes nine tribes. However, phylogenetic relationships among them remain largely unresolved, though different researches have been conducted based on both morphological and molecular data. However, ribosomal genes have never been used in tribe level phylogenetic analyses of Satyrinae. In this study we investigate for the first time the phylogenetic relationships among the tribes Elymniini, Amathusiini, Zetherini and Melanitini which are indicated to be a monophyletic group, and the Satyrini, using two ribosomal genes (28s rDNA and 16s rDNA and four protein-coding genes (EF-1α, COI, COII and Cytb. We mainly aim to assess the phylogenetic informativeness of the ribosomal genes as well as clarify the relationships among different tribes. Our results show the two ribosomal genes generally have the same high phylogenetic informativeness compared with EF-1α; and we infer the 28s rDNA would show better informativeness if the 28s rDNA sequence data for each sampling taxon are obtained in this study. The placement of the monotypic genus Callarge Leech in Zetherini is confirmed for the first time based on molecular evidence. In addition, our maximum likelihood (ML and Bayesian inference (BI trees consistently show that the involved Satyrinae including the Amathusiini is monophyletic with high support values. Although the relationships among the five tribes are identical among ML and BI analyses and are mostly strongly-supported in BI analysis, those in ML analysis are lowly- or moderately- supported. Therefore, the relationships among the related five tribes recovered herein need further verification based on more sampling taxa.

  11. Characterization of the nuclear ribosomal DNA units and phylogeny of Beta L. wild forms and cultivated beets.

    Science.gov (United States)

    Santoni, S; Bervillé, A

    1992-03-01

    The nuclear rDNA units of species belonging to the genus Beta were characterized using heterologous probes of flax (entire unit and 25S) and sunflower (6.1-kb Eco fragment containing the 18S, the entire intergenic spacer (IGS) and a small piece of the 25S). The physical maps of one species from each section of the genus was constructed by localization of the EcoRI, BamHI, HindIII, KpnI and SacI restriction sites. For each species a single individual was used to obtain total DNA. The major unit length is 11 kb, but variant length units at 10.4, 10.7 and 11.3 kb were found as minor forms. However, some individuals carried the 10.4-kb or the 10.7-kb variant length unit as the major form. For the variant length units of one species the restriction sites were conserved, so that the variation in length occurred in the IGS. The EcoRI fragment corresponding to the intergenic spacer appeared to be the best indicator of variation. The variable sequence in the IGS sometimes generated new restriction sites for the Corollinae and mainly, did so, for the Vulgares relative to the Procumbentes. The variable sites were able, to differentiate the three sections and species within the sections. Corollinae species belong to two different groups according to the absence or the presence of the BamHI (B4) site. The Vulgares species contain several unit types. We proposed that all the unit types derived from a unique unit, V-11-2.3, by unequal crossing-overs or conversion. We also supposed a homogenization mechanism because we found individuals homogeneous for every unit type. Among the cultivated beets, all the root beets contain only one rDNA unit type, V-11-2.9. Thus, we supposed that the common unit type of cultivated beets either brings a physiological advantage or is strictly linked to a favorable allele. It is likely that the rDNA unit of B. maritima were eliminated from sugar beet by the breeding process since they were not recovered. Whatever the process, we deduced that all the

  12. Characterization of the nuclear ribosomal DNA units and phylogeny of Beta L. wild forms and cultivated beets.

    Science.gov (United States)

    Santoni, S; Bervillé, A

    1992-03-01

    The nuclear rDNA units of species belonging to the genus Beta were characterized using heterologous probes of flax (entire unit and 25S) and sunflower (6.1-kb Eco fragment containing the 18S, the entire intergenic spacer (IGS) and a small piece of the 25S). The physical maps of one species from each section of the genus was constructed by localization of the EcoRI, BamHI, HindIII, KpnI and SacI restriction sites. For each species a single individual was used to obtain total DNA. The major unit length is 11 kb, but variant length units at 10.4, 10.7 and 11.3 kb were found as minor forms. However, some individuals carried the 10.4-kb or the 10.7-kb variant length unit as the major form. For the variant length units of one species the restriction sites were conserved, so that the variation in length occurred in the IGS. The EcoRI fragment corresponding to the intergenic spacer appeared to be the best indicator of variation. The variable sequence in the IGS sometimes generated new restriction sites for the Corollinae and mainly, did so, for the Vulgares relative to the Procumbentes. The variable sites were able, to differentiate the three sections and species within the sections. Corollinae species belong to two different groups according to the absence or the presence of the BamHI (B4) site. The Vulgares species contain several unit types. We proposed that all the unit types derived from a unique unit, V-11-2.3, by unequal crossing-overs or conversion. We also supposed a homogenization mechanism because we found individuals homogeneous for every unit type. Among the cultivated beets, all the root beets contain only one rDNA unit type, V-11-2.9. Thus, we supposed that the common unit type of cultivated beets either brings a physiological advantage or is strictly linked to a favorable allele. It is likely that the rDNA unit of B. maritima were eliminated from sugar beet by the breeding process since they were not recovered. Whatever the process, we deduced that all the

  13. 16S rRNA is Exchangeable in Escherichia coli%外源16S rRNA在大肠杆菌中的可替换性研究

    Institute of Scientific and Technical Information of China (English)

    李晓丹; 杨瑾; 曹慧; 崔中利

    2007-01-01

    16S rRNA对于构建功能性核糖体是十分重要的,人们普遍将其作为原核生物进化中保守的系统发育标志.为了进一步研究16S rRNA的进化,本文将Escherichia coli中最后一个拷贝的16S rRNA基因替换为Bacillus subtilis的16S rRNA 基因,得到了菌株SQ110BSX.菌株SQ110BSX的代时与出发菌株SQ110基本一致,但是SQ110BSX表现出冷敏感性,而且rRNA/蛋白比值为SQ110的148%.实验结果表明,菌株SQ110BSX中的核糖体效率明显下降.由于E.coli和B.subtilis在遗传距离上较远,两者的可替换性证明了16S rRNA的高度保守性.%16S rRNA plays an important role in the functional construction of ribosomes and is considered to be a conserved phylogenic marker of prokaryotic evolution.To elucidate the evolution of 16S rRNA, we succeeded in replacing the 16S rRNA gene of an E.coli strain with all rrn operons deleted with the 16S rRNA gene of Bacillus subtilis.We found that manipulated strain SQ110BSX showed similar characteristics with the starting E.coli strain SQ110 in terms of generation time.Strain SQ110BSX was cold sensitive, and the rRNA/protein ratio of it increased to 148% of the starting strain.These results indicate that ribosome efficiency has decreased.In view of the phylogenic distance between E.coli and B.subtilis, 16S rRNA was demonstrated to have a highly exchangeable property between these two species of different evolution status.

  14. Nonisotopic single-strand conformation polymorphism analysis of sequence variability in ribosomal DNA expansion segments within the genus Trichinella (Nematoda: Adenophorea).

    Science.gov (United States)

    Gasser, Robin B; Hu, Min; Abs El-Osta, Youssef G; Zarlenga, Dante S; Pozio, Edoardo

    2004-10-01

    A nonisotopic single-strand conformation polymorphism (SSCP) approach was employed to 'fingerprint' sequence variability in the expansion segment 5 (ES5) of domain IV and the D3 domain of nuclear ribosomal DNA within and/or among isolates and individual muscle (first-stage) larvae representing all currently recognized species/genotypes of Trichinella. In addition, phylogenetic analyses of the D3 sequence data set, employing three different tree-building algorithms, examined the relationships among all of them. These analyses showed strong support that the encapsulated species T. spiralis and T. nelsoni formed a group to the exclusion of the other encapsulated species T. britovi and its related genotypes Trichinella T8 and T9 and T. murrelli, and T. nativa and Trichinella T6, and strong support that T. nativa and Trichinella T6 grouped together. Also, these eight encapsulated members grouped to the exclusion of the nonencapsulated species T. papuae and T. zimbabwensis and the three representatives of T. pseudospiralis investigated. The findings showed that nonencapsulated species constitute a complex group which is distinct from the encapsulated species and supported the current hypothesis that encapsulated Trichinella group external to the nonencapsulated forms, in accordance with independent biological and biochemical data sets. PMID:15490459

  15. Ribo HRM--detection of inter- and intra-species polymorphisms within ribosomal DNA by high resolution melting analysis supported by application of artificial allelic standards.

    Science.gov (United States)

    Masny, Aleksander; Jagiełło, Agata; Płucienniczak, Grażyna; Golab, Elzbieta

    2012-09-01

    Ribo HRM, a single-tube PCR and high resolution melting (HRM) assay for detection of polymorphisms in the large subunit ribosomal DNA expansion segment V, was developed on a Trichinella model. Four Trichinella species: T. spiralis (isolates ISS3 and ISS160), T. nativa (isolates ISS10 and ISS70), T. britovi (isolates ISS2 and ISS392) and T. pseudospiralis (isolates ISS13 and ISS1348) were genotyped. Cloned allelic variants of the expansion segment V were used as standards to prepare reference HRM curves characteristic for single sequences and mixtures of several cloned sequences imitating allelic composition detected in Trichinella isolates. Using the primer pair Tsr1 and Trich1bi, it was possible to amplify a fragment of the ESV and detect PCR products obtained from the genomic DNA of pools of larvae belonging to the four investigated species: T. pseudospiralis, T. spiralis, T. britovi and T. nativa, in a single tube Real-Time PCR reaction. Differences in the shape of the HRM curves of Trichinella isolates suggested the presence of differences between examined isolates of T. nativa, T. britovi and T. pseudospiralis species. No differences were observed between T. spiralis isolates. The presence of polymorphisms within the amplified ESV sequence fragment of T. nativa T. britovi and T. pseudospiralis was confirmed by sequencing of the cloned PCR products. Novel sequences were discovered and deposited in GenBank (GenBank IDs: JN971020-JN971027, JN120902.1, JN120903.1, JN120904.1, JN120906.1, JN120905.1). Screening the ESV region of Trichinella for polymorphism is possible using the genotyping assay Ribo HRM at the current state of its development. The Ribo HRM assay could be useful in phylogenetic studies of the Trichinella genus. PMID:22766326

  16. PFR²: a curated database of planktonic foraminifera 18S ribosomal DNA as a resource for studies of plankton ecology, biogeography and evolution.

    Science.gov (United States)

    Morard, Raphaël; Darling, Kate F; Mahé, Frédéric; Audic, Stéphane; Ujiié, Yurika; Weiner, Agnes K M; André, Aurore; Seears, Heidi A; Wade, Christopher M; Quillévéré, Frédéric; Douady, Christophe J; Escarguel, Gilles; de Garidel-Thoron, Thibault; Siccha, Michael; Kucera, Michal; de Vargas, Colomban

    2015-11-01

    Planktonic foraminifera (Rhizaria) are ubiquitous marine pelagic protists producing calcareous shells with conspicuous morphology. They play an important role in the marine carbon cycle, and their exceptional fossil record serves as the basis for biochronostratigraphy and past climate reconstructions. A major worldwide sampling effort over the last two decades has resulted in the establishment of multiple large collections of cryopreserved individual planktonic foraminifera samples. Thousands of 18S rDNA partial sequences have been generated, representing all major known morphological taxa across their worldwide oceanic range. This comprehensive data coverage provides an opportunity to assess patterns of molecular ecology and evolution in a holistic way for an entire group of planktonic protists. We combined all available published and unpublished genetic data to build PFR(2), the Planktonic foraminifera Ribosomal Reference database. The first version of the database includes 3322 reference 18S rDNA sequences belonging to 32 of the 47 known morphospecies of extant planktonic foraminifera, collected from 460 oceanic stations. All sequences have been rigorously taxonomically curated using a six-rank annotation system fully resolved to the morphological species level and linked to a series of metadata. The PFR(2) website, available at http://pfr2.sb-roscoff.fr, allows downloading the entire database or specific sections, as well as the identification of new planktonic foraminiferal sequences. Its novel, fully documented curation process integrates advances in morphological and molecular taxonomy. It allows for an increase in its taxonomic resolution and assures that integrity is maintained by including a complete contingency tracking of annotations and assuring that the annotations remain internally consistent. PMID:25828689

  17. Phylogeny of the sundews, Drosera (Droseraceae), based on chloroplast rbcL and nuclear 18S ribosomal DNA Sequences.

    Science.gov (United States)

    Rivadavia, Fernando; Kondo, Katsuhiko; Kato, Masahiro; Hasebe, Mitsuyasu

    2003-01-01

    The sundew genus Drosera consists of carnivorous plants with active flypaper traps and includes nearly 150 species distributed mainly in Australia, Africa, and South America, with some Northern Hemisphere species. In addition to confused intrageneric classification of Drosera, the intergeneric relationships among the Drosera and two other genera in the Droseraceae with snap traps, Dionaea and Aldrovanda, are problematic. We conducted phylogenetic analyses of DNA sequences of the chloroplast rbcL gene for 59 species of Drosera, covering all sections except one. These analyses revealed that five of 11 sections, including three monotypic sections, are polyphyletic. Combined rbcL and 18S rDNA sequence data were used to infer phylogenetic relationships among Drosera, Dionaea, and Aldrovanda. This analysis revealed that all Drosera species form a clade sister to a clade including Dionaea and Aldrovanda, suggesting that the snap traps of Aldrovanda and Dionaea are homologous despite their morphological differences. MacClade reconstructions indicated that multiple episodes of aneuploidy occurred in a clade that includes mainly Australian species, while the chromosome numbers in the other clades are not as variable. Drosera regia, which is native to South Africa, and most species native to Australia, were clustered basally, suggesting that Drosera originated in Africa or Australia. The rbcL tree indicates that Australian species expanded their distribution to South America and then to Africa. Expansion of distribution to the Northern Hemisphere from the Southern Hemispere occurred in a few different lineages. PMID:21659087

  18. 硬软蒺藜rDNA-ITS基因序列的测定和比较%Fingerprinting of Nucleotide Sequences of Ribosomal DNA Internal Transcribed Spacer in Tribulus terrestris L. and Atriplex centralasiatica Iljin

    Institute of Scientific and Technical Information of China (English)

    张素军; 瞿伟菁; 李进

    2006-01-01

    用CTAB法提取总DNA,合成位于18 S rDNA和26S rDNA上的两条各20bp的引物,通过PCR扩增ITS的全序列,对PCR产物直接测序,分别获得了硬蒺藜(Tribulus terrestris L.)和软蒺藜(Atriples centralasiatica Iljin)的核糖体RNA基因-rDNA内转录间隔区(ribosomal DNA internal transcribed spacer,rDNA-ITS)的序列643 bp和607bp,其碱基总差异率为36.16%,其中,ITS1的碱基差异率为55.81%;5.8 S的碱基差异率为6.59%;ITS2的碱基差异率为56.77%.这种差异,以及基因序列本身,为硬软蒺藜的区别和种质资源鉴定提供了分子依据.

  19. Analysis of the microbiome: Advantages of whole genome shotgun versus 16S amplicon sequencing.

    Science.gov (United States)

    Ranjan, Ravi; Rani, Asha; Metwally, Ahmed; McGee, Halvor S; Perkins, David L

    2016-01-22

    The human microbiome has emerged as a major player in regulating human health and disease. Translational studies of the microbiome have the potential to indicate clinical applications such as fecal transplants and probiotics. However, one major issue is accurate identification of microbes constituting the microbiota. Studies of the microbiome have frequently utilized sequencing of the conserved 16S ribosomal RNA (rRNA) gene. We present a comparative study of an alternative approach using whole genome shotgun sequencing (WGS). In the present study, we analyzed the human fecal microbiome compiling a total of 194.1 × 10(6) reads from a single sample using multiple sequencing methods and platforms. Specifically, after establishing the reproducibility of our methods with extensive multiplexing, we compared: 1) The 16S rRNA amplicon versus the WGS method, 2) the Illumina HiSeq versus MiSeq platforms, 3) the analysis of reads versus de novo assembled contigs, and 4) the effect of shorter versus longer reads. Our study demonstrates that whole genome shotgun sequencing has multiple advantages compared with the 16S amplicon method including enhanced detection of bacterial species, increased detection of diversity and increased prediction of genes. In addition, increased length, either due to longer reads or the assembly of contigs, improved the accuracy of species detection.

  20. Identification of nucleosome assembly protein 1 (NAP1) as an interacting partner of plant ribosomal protein S6 (RPS6) and a positive regulator of rDNA transcription

    International Nuclear Information System (INIS)

    The ribosomal protein S6 (RPS6) is a downstream component of the signaling mediated by the target of rapamycin (TOR) kinase that acts as a central regulator of the key metabolic processes, such as protein translation and ribosome biogenesis, in response to various environmental cues. In our previous study, we identified a novel role of plant RPS6, which negatively regulates rDNA transcription, forming a complex with a plant-specific histone deacetylase, AtHD2B. Here we report that the Arabidopsis RPS6 interacts additionally with a histone chaperone, nucleosome assembly protein 1(AtNAP1;1). The interaction does not appear to preclude the association of RPS6 with AtHD2B, as the AtNAP1 was also able to interact with AtHD2B as well as with an RPS6-AtHD2B fusion protein in the BiFC assay and pulldown experiment. Similar to a positive effect of the ribosomal S6 kinase 1 (AtS6K1) on rDNA transcription observed in this study, overexpression or down regulation of the AtNAP1;1 resulted in concomitant increase and decrease, respectively, in rDNA transcription suggesting a positive regulatory role played by AtNAP1 in plant rDNA transcription, possibly through derepression of the negative effect of the RPS6-AtHD2B complex. - Highlights: • Nucleosome assembly protein 1 (AtNAP1) interacts with RPS6 as well as with AtHD2B. • rDNA transcription is regulated S6K1. • Overexpression or down regulation of AtNAP1 results in concomitant increase or decrease in rDNA transcription

  1. Identification of nucleosome assembly protein 1 (NAP1) as an interacting partner of plant ribosomal protein S6 (RPS6) and a positive regulator of rDNA transcription

    Energy Technology Data Exchange (ETDEWEB)

    Son, Ora [Department of Biological Science, Sookmyung Women' s University, Seoul 140-742 (Korea, Republic of); Kim, Sunghan [Department of Biological Science, Sookmyung Women' s University, Seoul 140-742 (Korea, Republic of); Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of); Shin, Yun-jeong [Department of Biological Science, Sookmyung Women' s University, Seoul 140-742 (Korea, Republic of); Kim, Woo-Young [College of Pharmacy, Sookmyung Women' s University, Seoul 140-742 (Korea, Republic of); Koh, Hee-Jong, E-mail: heejkoh@snu.ac.kr [Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of); Cheon, Choong-Ill, E-mail: ccheon@sookmyung.ac.kr [Department of Biological Science, Sookmyung Women' s University, Seoul 140-742 (Korea, Republic of)

    2015-09-18

    The ribosomal protein S6 (RPS6) is a downstream component of the signaling mediated by the target of rapamycin (TOR) kinase that acts as a central regulator of the key metabolic processes, such as protein translation and ribosome biogenesis, in response to various environmental cues. In our previous study, we identified a novel role of plant RPS6, which negatively regulates rDNA transcription, forming a complex with a plant-specific histone deacetylase, AtHD2B. Here we report that the Arabidopsis RPS6 interacts additionally with a histone chaperone, nucleosome assembly protein 1(AtNAP1;1). The interaction does not appear to preclude the association of RPS6 with AtHD2B, as the AtNAP1 was also able to interact with AtHD2B as well as with an RPS6-AtHD2B fusion protein in the BiFC assay and pulldown experiment. Similar to a positive effect of the ribosomal S6 kinase 1 (AtS6K1) on rDNA transcription observed in this study, overexpression or down regulation of the AtNAP1;1 resulted in concomitant increase and decrease, respectively, in rDNA transcription suggesting a positive regulatory role played by AtNAP1 in plant rDNA transcription, possibly through derepression of the negative effect of the RPS6-AtHD2B complex. - Highlights: • Nucleosome assembly protein 1 (AtNAP1) interacts with RPS6 as well as with AtHD2B. • rDNA transcription is regulated S6K1. • Overexpression or down regulation of AtNAP1 results in concomitant increase or decrease in rDNA transcription.

  2. Diagnostic Utility of Broad Range Bacterial 16S rRNA Gene PCR with Degradation of Human and Free Bacterial DNA in Bloodstream Infection Is More Sensitive Than an In-House Developed PCR without Degradation of Human and Free Bacterial DNA

    Directory of Open Access Journals (Sweden)

    Petra Rogina

    2014-01-01

    Full Text Available We compared a commercial broad range 16S rRNA gene PCR assay (SepsiTest to an in-house developed assay (IHP. We assessed whether CD64 index, a biomarker of bacterial infection, can be used to exclude patients with a low probability of systemic bacterial infection. From January to March 2010, 23 patients with suspected sepsis were enrolled. CD64 index, procalcitonin, and C-reactive protein were measured on admission. Broad range 16S rRNA gene PCR was performed from whole blood (SepsiTest or blood plasma (IHP and compared to blood culture results. Blood samples spiked with Staphylococcus aureus were used to assess sensitivity of the molecular assays in vitro. CD64 index was lower in patients where possible sepsis was excluded than in patients with microbiologically confirmed sepsis (P=0.004. SepsiTest identified more relevant pathogens than blood cultures (P=0.008; in three patients (13% results from blood culture and SepsiTest were congruent, whereas in four cases (17.4% relevant pathogens were detected by SepsiTest only. In vitro spiking experiments suggested equal sensitivity of SepsiTest and IHP. A diagnostic algorithm using CD64 index as a decision maker to perform SepsiTest shows improved detection of pathogens in patients with suspected blood stream infection and may enable earlier targeted antibiotic therapy.

  3. Isolation of temperature-sensitive mutants of 16 S rRNA in Escherichia coli

    DEFF Research Database (Denmark)

    Triman, K; Becker, E; Dammel, C;

    1989-01-01

    Temperature-sensitive mutants have been isolated following hydroxylamine mutagenesis of a plasmid containing Escherichia coli rRNA genes carrying selectable markers for spectinomycin resistance (U1192 in 16 S rRNA) and erythromycin resistance (G2058 in 23 S rRNA). These antibiotic resistance...... alleles, originally identified by Morgan and co-workers, enable us to follow expression of cloned rRNA genes in vivo. Recessive mutations causing the loss of expression of the cloned 16 S rRNA gene were identified by the loss of the ability of cells to survive on media containing spectinomycin....... The mutations were localized by in vitro restriction fragment replacement followed by in vivo marker rescue and were identified by DNA sequence analysis. We report here seven single-base alterations in 16 S rRNA (A146, U153, A350, A359, A538, A1292 and U1293), five of which produce temperature...

  4. Characterization of ancient DNA supports long-term survival of Haloarchaea.

    Science.gov (United States)

    Sankaranarayanan, Krithivasan; Lowenstein, Tim K; Timofeeff, Michael N; Schubert, Brian A; Lum, J Koji

    2014-07-01

    Bacteria and archaea isolated from crystals of halite 10(4) to 10(8) years old suggest long-term survival of halophilic microorganisms, but the results are controversial. Independent verification of the authenticity of reputed living prokaryotes in ancient salt is required because of the high potential for environmental and laboratory contamination. Low success rates of prokaryote cultivation from ancient halite, however, hamper direct replication experiments. In such cases, culture-independent approaches that use the polymerase chain reaction (PCR) and sequencing of 16S ribosomal DNA are a robust alternative. Here, we use amplification, cloning, and sequencing of 16S ribosomal DNA to investigate the authenticity of halophilic archaea cultured from subsurface halite, Death Valley, California, 22,000 to 34,000 years old. We recovered 16S ribosomal DNA sequences that are identical, or nearly so (>99%), to two strains, Natronomonas DV462A and Halorubrum DV427, which were previously isolated from the same halite interval. These results provide the best independent support to date for the long-term survival of halophilic archaea in ancient halite. PCR-based approaches are sensitive to small amounts of DNA and could allow investigation of even older halites, 10(6) to 10(8) years old, from which microbial cultures have been reported. Such studies of microbial life in ancient salt are particularly important as we search for microbial signatures in similar deposits on Mars and elsewhere in the Solar System. PMID:24977469

  5. Isolation of a genomic DNA for Jatropha curcas ribosome inactivating protein and its tobacco transformation%麻风树核糖体失活蛋白的基因组DNA分离及其转化烟草分析

    Institute of Scientific and Technical Information of China (English)

    罗言云; 魏琴; 黄明星; 徐莺; 陈放

    2006-01-01

    Genomic DNA for Jatropha curcas ribosome inactivating protein (JRIP) was cloned from total DNA of its leaves by polymerase chain reaction (PCR). The no intron character was confirmed. The plant expression vector pBI121-JRIP was constructed by inserting the JRIP gene into pBI121 plasmid. The recombinant Agrobacterium EHA105 strain harboring pBI121-JRIP was constructed by conducting pBI121-JRIP to strain EHA 105. PCR and Southern blotting were carried out, and the results proved that the JRIP gene was integrated into tobacco genome. It might provide a new material for disease resistance tobacco species breeding.

  6. Identification to the species level of Lactobacillus isolated in probiotic prospecting studies of human, animal or food origin by 16S-23S rRNA restriction profiling

    Directory of Open Access Journals (Sweden)

    Neumann Elisabeth

    2005-03-01

    Full Text Available Abstract Background The accurate identification of Lactobacillus and other co-isolated bacteria during microbial ecological studies of ecosystems such as the human or animal intestinal tracts and food products is a hard task by phenotypic methods requiring additional tests such as protein and/or lipids profiling. Results Bacteria isolated in different probiotic prospecting studies, using de Man, Rogosa and Sharpe medium (MRS, were typed at species level by PCR amplification of 16S-23S rRNA intergenic spacers using universal primers that anneal within 16S and 23S genes, followed by restriction digestion analyses of PCR products. The set of enzymes chosen differentiates most species of Lactobacillus genus and also co-isolated bacteria such as Enterococcus, Streptococcus, Weissella, Staphylococcus, and Escherichia species. The in silico predictions of restriction patterns generated by the Lactobacillus shorter spacers digested with 11 restriction enzymes with 6 bp specificities allowed us to distinguish almost all isolates at the species level but not at the subspecies one. Simultaneous theoretical digestions of the three spacers (long, medium and short with the same set of enzymes provided more complex patterns and allowed us to distinguish the species without purifying and cloning of PCR products. Conclusion Lactobacillus isolates and several other strains of bacteria co-isolated on MRS medium from gastrointestinal ecosystem and fermented food products could be identified using DNA fingerprints generated by restriction endonucleases. The methodology based on amplified ribosomal DNA restriction analysis (ARDRA is easier, faster and more accurate than the current methodologies based on fermentation profiles, used in most laboratories for the purpose of identification of these bacteria in different prospecting studies.

  7. 16S rRNA基因测序技术在肝脓疡细菌鉴定中的作用%Usefulness of 16S rRNA Gene Sequencing for Identification of Bacteria from Pyogenic Liver Abscess

    Institute of Scientific and Technical Information of China (English)

    宋伦圭

    2014-01-01

    目的:评价16S核糖体RNA (rRNA)基因测序在肝脓疡中细菌鉴定中的应用价值。方法2012年1月-2013年12月间共20例肝脓疡行经皮置管引流的患者,分别行脓液培养,血培养和16S rRNA基因测序。利用454 GS Junior System对脓液基因组DNA行PCR和16S rRNA基因测序。脓液培养,血液培养和16S rRNA 基因测序结果进行分别评价。结果脓液和血液培养阳性的患者分别是9例(45%)和4例(20%)。16S rRNA基因测序细菌鉴定率为90%,明显高于传统的培养方法。结论16S rRNA基因测序方法较传统的培养方法能更准确和有效对肝脓疡进行细菌鉴定。%Background/Aims To evaluate the usefulness of 16S ribosomal RNA (rRNA) gene sequencing for an accurate and better identification of bacteria from pyogenic liver abscess (PLA). Methodology 20 patients with PLA were included who underwent percutaneous catheter drainage, abscess culture, blood culture and 16S rRNA gene sequencing for isolates from January 2012 to December 2013. Genomic DNAs of abscess fluids were subjected to PCR and sequencing of 16S rRNA gene by on a 454 GS Junior System. The results were evaluated between abscess cultures, blood and 16S rRNA gene sequencing for isolates. Results Abscess and blood cultures were positive in 9 (45%) and 4 (20%) patients, respectively. The 16S rRNA gene sequencing showed with 90% identification of bacteria a significantly greater identification than conventional cultured methods. Conclusion This study showed a greater usefulness of 16S rRNA gene sequencing than conventional cultured methods for accurate and better identification of bacteria from PLA.

  8. Analysis of bacterial community structure in Saba-Narezushi (Narezushi of Mackerel) by 16S rRNA gene clone library.

    Science.gov (United States)

    Matsui, Hiroki; Tsuchiya, Rie; Isobe, Yuka; Narita, Miyo

    2013-08-01

    Narezushi, a derivation of sushi, is a traditional Japanese food made by fermenting salted fish meat and cooked rice together. In this study, the microbial diversity of saba-narezushi (narezushi of mackerel, Scomber japonicus) was analyzed by the 16S ribosomal RNA gene clone library method. Chemical composition was also analyzed to compare with different kinds of narezushi. The chemical composition of the narezushi was similar to those obtained from samma-narezushi. Ninety-four clones were randomly selected and DNA sequences of cloned fragments (approx. 890 bp) were analyzed. The DNA sequences obtained were phylogenetically analyzed. The expected operational taxonomy units (OTUs) by Chao1 estimates and Shannon-Wiener index (H') at 97% identity threshold were 48 and 1.822, respectively. The sequence similarity of the cloned fragment was equal to or higher than 98% of the sequence of cultivated bacterial species in the public database. Most of the clones (85%) belonged to lactic acid bacteria (LAB). Lactobacillus curvatus was the most abundant species followed by Lactococcus piscium and Leuconostoc gasicomitatum, suggesting that these bacteria play important roles in the fermentation of saba-narezushi. PMID:24425983

  9. Single-molecule long-read 16S sequencing to characterize the lung microbiome from mechanically ventilated patients with suspected pneumonia.

    Science.gov (United States)

    Toma, Ian; Siegel, Marc O; Keiser, John; Yakovleva, Anna; Kim, Alvin; Davenport, Lionel; Devaney, Joseph; Hoffman, Eric P; Alsubail, Rami; Crandall, Keith A; Castro-Nallar, Eduardo; Pérez-Losada, Marcos; Hilton, Sarah K; Chawla, Lakhmir S; McCaffrey, Timothy A; Simon, Gary L

    2014-11-01

    In critically ill patients, the development of pneumonia results in significant morbidity and mortality and additional health care costs. The accurate and rapid identification of the microbial pathogens in patients with pulmonary infections might lead to targeted antimicrobial therapy with potentially fewer adverse effects and lower costs. Major advances in next-generation sequencing (NGS) allow culture-independent identification of pathogens. The present study used NGS of essentially full-length PCR-amplified 16S ribosomal DNA from the bronchial aspirates of intubated patients with suspected pneumonia. The results from 61 patients demonstrated that sufficient DNA was obtained from 72% of samples, 44% of which (27 samples) yielded PCR amplimers suitable for NGS. Out of the 27 sequenced samples, only 20 had bacterial culture growth, while the microbiological and NGS identification of bacteria coincided in 17 (85%) of these samples. Despite the lack of bacterial growth in 7 samples that yielded amplimers and were sequenced, the NGS identified a number of bacterial species in these samples. Overall, a significant diversity of bacterial species was identified from the same genus as the predominant cultured pathogens. The numbers of NGS-identifiable bacterial genera were consistently higher than identified by standard microbiological methods. As technical advances reduce the processing and sequencing times, NGS-based methods will ultimately be able to provide clinicians with rapid, precise, culture-independent identification of bacterial, fungal, and viral pathogens and their antimicrobial sensitivity profiles. PMID:25143582

  10. Molecular characterisation of three regions of the nuclear ribosomal DNA unit and the mitochondrial cox1 gene of Sarcocystis fusiformis from water buffaloes (Bubalus bubalis) in Egypt.

    Science.gov (United States)

    Gjerde, Bjørn; Hilali, Mosaad; Mawgood, Sahar Abdel

    2015-09-01

    A total of 33 macroscopically visible (3-11 × 1-5 mm) sarcocysts of Sarcocystis fusiformis were excised from the oesophagus of 12 freshly slaughtered water buffalos in Giza, Egypt. Genomic DNA was extracted from the sarcocysts, and all isolates were characterised at the mitochondrial cytochrome c oxidase subunit I (cox1) gene through PCR amplification and direct sequencing, whereas a few selected isolates were characterised at the 18S and 28S ribosomal (r) RNA genes and the internal transcribed spacer 1 (ITS1) region of the nuclear rDNA unit following cloning. Among the 33 cox1 sequences (1,038-bp long), there was a total of 13 haplotypes, differing from each other by one to seven substitutions and sharing an identity of 99.3-99.9 %. In comparison, the sequence identity was 98.8-99.0 % among eight complete 18S rRNA gene sequences (1,873-1,879-bp long), 98.1-100 % among 28 complete ITS1 sequences (853-864-bp long) and 97.4-99.6 % among five partial 28S rRNA gene sequences (1,607-1,622 bp). At the three nuclear loci, the intraspecific (and intra-isolate) sequence variation was due to both substitutions and indels, which necessitated cloning of the PCR products before sequencing. Some additional clones of the 18S and 28S rRNA genes were highly divergent from the more typical clones, but the true nature of these aberrant clones could not be determined. Sequence comparisons and phylogenetic analyses based on either 18S rRNA gene or cox1 nucleotide sequences, placed S. fusiformis closest to Sarcocystis cafferi from the African buffalo, but only the analyses based on cox1 data separated the two taxa clearly from each other and showed that they were separate species (monophyletic clusters and 93 % sequence identity at cox1 versus interleaved sequences and 98.7-99.1 % sequence identity at the 18S rRNA gene). Two cats experimentally infected with sarcocysts of S. fusiformis started shedding small numbers of sporocysts 8-10 days post-infection (dpi) and were euthanized 15

  11. Engineering the rRNA decoding site of eukaryotic cytosolic ribosomes in bacteria

    OpenAIRE

    Hobbie, S N; Kalapala, S K; Akshay, S.; Bruell, C M; S. Schmidt; Dabow, S; Vasella, A; Sander, P; Böttger, E C

    2007-01-01

    Structural and genetic studies on prokaryotic ribosomes have provided important insights into fundamental aspects of protein synthesis and translational control and its interaction with ribosomal drugs. Comparable mechanistic studies in eukaryotes are mainly hampered by the absence of both high-resolution crystal structures and efficient genetic models. To study the interaction of aminoglycoside antibiotics with selected eukaryotic ribosomes, we replaced the bacterial drug binding site in 16S...

  12. International interlaboratory study comparing single organism 16S rRNA gene sequencing data: Beyond consensus sequence comparisons.

    Science.gov (United States)

    Olson, Nathan D; Lund, Steven P; Zook, Justin M; Rojas-Cornejo, Fabiola; Beck, Brian; Foy, Carole; Huggett, Jim; Whale, Alexandra S; Sui, Zhiwei; Baoutina, Anna; Dobeson, Michael; Partis, Lina; Morrow, Jayne B

    2015-03-01

    This study presents the results from an interlaboratory sequencing study for which we developed a novel high-resolution method for comparing data from different sequencing platforms for a multi-copy, paralogous gene. The combination of PCR amplification and 16S ribosomal RNA gene (16S rRNA) sequencing has revolutionized bacteriology by enabling rapid identification, frequently without the need for culture. To assess variability between laboratories in sequencing 16S rRNA, six laboratories sequenced the gene encoding the 16S rRNA from Escherichia coli O157:H7 strain EDL933 and Listeria monocytogenes serovar 4b strain NCTC11994. Participants performed sequencing methods and protocols available in their laboratories: Sanger sequencing, Roche 454 pyrosequencing(®), or Ion Torrent PGM(®). The sequencing data were evaluated on three levels: (1) identity of biologically conserved position, (2) ratio of 16S rRNA gene copies featuring identified variants, and (3) the collection of variant combinations in a set of 16S rRNA gene copies. The same set of biologically conserved positions was identified for each sequencing method. Analytical methods using Bayesian and maximum likelihood statistics were developed to estimate variant copy ratios, which describe the ratio of nucleotides at each identified biologically variable position, as well as the likely set of variant combinations present in 16S rRNA gene copies. Our results indicate that estimated variant copy ratios at biologically variable positions were only reproducible for high throughput sequencing methods. Furthermore, the likely variant combination set was only reproducible with increased sequencing depth and longer read lengths. We also demonstrate novel methods for evaluating variable positions when comparing multi-copy gene sequence data from multiple laboratories generated using multiple sequencing technologies.

  13. International interlaboratory study comparing single organism 16S rRNA gene sequencing data: Beyond consensus sequence comparisons

    Directory of Open Access Journals (Sweden)

    Nathan D. Olson

    2015-03-01

    Full Text Available This study presents the results from an interlaboratory sequencing study for which we developed a novel high-resolution method for comparing data from different sequencing platforms for a multi-copy, paralogous gene. The combination of PCR amplification and 16S ribosomal RNA gene (16S rRNA sequencing has revolutionized bacteriology by enabling rapid identification, frequently without the need for culture. To assess variability between laboratories in sequencing 16S rRNA, six laboratories sequenced the gene encoding the 16S rRNA from Escherichia coli O157:H7 strain EDL933 and Listeria monocytogenes serovar 4b strain NCTC11994. Participants performed sequencing methods and protocols available in their laboratories: Sanger sequencing, Roche 454 pyrosequencing®, or Ion Torrent PGM®. The sequencing data were evaluated on three levels: (1 identity of biologically conserved position, (2 ratio of 16S rRNA gene copies featuring identified variants, and (3 the collection of variant combinations in a set of 16S rRNA gene copies. The same set of biologically conserved positions was identified for each sequencing method. Analytical methods using Bayesian and maximum likelihood statistics were developed to estimate variant copy ratios, which describe the ratio of nucleotides at each identified biologically variable position, as well as the likely set of variant combinations present in 16S rRNA gene copies. Our results indicate that estimated variant copy ratios at biologically variable positions were only reproducible for high throughput sequencing methods. Furthermore, the likely variant combination set was only reproducible with increased sequencing depth and longer read lengths. We also demonstrate novel methods for evaluating variable positions when comparing multi-copy gene sequence data from multiple laboratories generated using multiple sequencing technologies.

  14. Utilización del patrón de restricción del DNA codificante para el RNA Ribosomal de la subunidad pequeña para la caracterización de Apicomplexa

    Directory of Open Access Journals (Sweden)

    López Adelaida

    1996-12-01

    Full Text Available Los Apicomplexos constituyen un phylum de protozoarios que se caracterizan por ser parásitos obligados de una gran variedad de huéspedes vertebrados e invertebrados. Hoy en día hay fuertes polémicas en tomo a su clasificación taxonómica, sus relaciones filogenéticas, y los patrones de coevolución con sus hospederos. El gen que codifica para el ARN ribosomal de la subunidad pequeña (ARN-SURp se utiliza como marcador molecular para resolver estas inquietudes. A partir del ADN de las especies de la familia Sarcocystidae (Sarcocystis cruzi, Sarcocystis sp. de Didelphis marsupialis y Sarcocystis sp. de Columbina talpacoti y Toxoplasma gondii, y de especies de la familia Plasmodiidae (Plasmodium de Anolis chloris, P. simium, y P. falciparumi, se amplificó por PCR el gen que codifica para el ARN de la subunidad ribosomal pequeña (ARN- SURp usando los iniciadores P5-P3, 0009-2134 Y566R-567R. Se compararon
    los patrones de restricción Hind III, Eco RI, Sau 3AI y Alw 261 del DNA ribosomal. La prueba de riboprini mostró que además de discriminar entre familias permite caracterizar diferencias a nivel de género y especie.Apicomplexa is a Protozoa phylum in which all members are obliged parasites of a wide range of vertebrate and invertebrate hosts. There is an ongoing controversy on
    systematics, phylogenetic relationships and parasite - host coevolution patterns. The SSU ribosomal gen has been used as a molecular marker in order to solve these issues.
    From DNA of the species of the Sarcocystidae family (Sarcocystis cruzi, Sarcocystis sp. from Didelphis marsupialis, Sarcocystis sp. from Columbina talpacoti and Toxoplasma
    gondii, and from the species of the Plasmodiidae family (Plasmodium from Anolis ehloris, P. simium, and P. falciparum, the SSU ribosomal DNA fragemnt was
    amplified by PCR, using the pair of primers P5-P3, 0009-2134 and 566R-567R. Hind III, Eco RI, Sau 3AI and Alw 261 restriction pattems were compared

  15. Effects of 16S rRNA gene mutations on tetracycline resistance in Helicobacter pylori

    OpenAIRE

    Gerrits, Monique; Berning, M.; Vliet, Arnoud; Kuipers, Ernst; Kusters, Johannes

    2003-01-01

    textabstractThe triple-base-pair 16S rDNA mutation AGA(926-928)-->TTC mediates high-level tetracycline resistance in Helicobacter pylori. In contrast, single- and double-base-pair mutations mediated only low-level tetracycline resistance and decreased growth rates in the presence of tetracycline, explaining the preference for the TTC mutation in tetracycline-resistant H. pylori isolates.

  16. Multi-site-specific 16S rRNA methyltransferase RsmF from Thermus thermophilus

    DEFF Research Database (Denmark)

    Demirci, Hasan; Larsen, Line H G; Hansen, Trine;

    2010-01-01

    Cells devote a significant effort toward the production of multiple modified nucleotides in rRNAs, which fine tune the ribosome function. Here, we report that two methyltransferases, RsmB and RsmF, are responsible for all four 5-methylcytidine (m(5)C) modifications in 16S rRNA of Thermus...... thermophilus. Like Escherichia coli RsmB, T. thermophilus RsmB produces m(5)C967. In contrast to E. coli RsmF, which introduces a single m(5)C1407 modification, T. thermophilus RsmF modifies three positions, generating m(5)C1400 and m(5)C1404 in addition to m(5)C1407. These three residues are clustered near...

  17. Complete ecological isolation and cryptic diversity in Polynucleobacter bacteria not resolved by 16S rRNA gene sequences.

    Science.gov (United States)

    Hahn, Martin W; Jezberová, Jitka; Koll, Ulrike; Saueressig-Beck, Tanja; Schmidt, Johanna

    2016-07-01

    Transplantation experiments and genome comparisons were used to determine if lineages of planktonic Polynucleobacter almost indistinguishable by their 16S ribosomal RNA (rRNA) sequences differ distinctively in their ecophysiological and genomic traits. The results of three transplantation experiments differing in complexity of biotic interactions revealed complete ecological isolation between some of the lineages. This pattern fits well to the previously detected environmental distribution of lineages along chemical gradients, as well as to differences in gene content putatively providing adaptation to chemically distinct habitats. Patterns of distribution of iron transporter genes across 209 Polynucleobacter strains obtained from freshwater systems and representing a broad pH spectrum further emphasize differences in habitat-specific adaptations. Genome comparisons of six strains sharing ⩾99% 16S rRNA similarities suggested that each strain represents a distinct species. Comparison of sequence diversity among genomes with sequence diversity among 240 cultivated Polynucleobacter strains indicated a large cryptic species complex not resolvable by 16S rRNA sequences. The revealed ecological isolation and cryptic diversity in Polynucleobacter bacteria is crucial in the interpretation of diversity studies on freshwater bacterioplankton based on ribosomal sequences.

  18. Oral microbiome profiles: 16S rRNA pyrosequencing and microarray assay comparison.

    Directory of Open Access Journals (Sweden)

    Jiyoung Ahn

    Full Text Available OBJECTIVES: The human oral microbiome is potentially related to diverse health conditions and high-throughput technology provides the possibility of surveying microbial community structure at high resolution. We compared two oral microbiome survey methods: broad-based microbiome identification by 16S rRNA gene sequencing and targeted characterization of microbes by custom DNA microarray. METHODS: Oral wash samples were collected from 20 individuals at Memorial Sloan-Kettering Cancer Center. 16S rRNA gene survey was performed by 454 pyrosequencing of the V3-V5 region (450 bp. Targeted identification by DNA microarray was carried out with the Human Oral Microbe Identification Microarray (HOMIM. Correlations and relative abundance were compared at phylum and genus level, between 16S rRNA sequence read ratio and HOMIM hybridization intensity. RESULTS: The major phyla, Firmicutes, Proteobacteria, Bacteroidetes, Actinobacteria, and Fusobacteria were identified with high correlation by the two methods (r = 0.70∼0.86. 16S rRNA gene pyrosequencing identified 77 genera and HOMIM identified 49, with 37 genera detected by both methods; more than 98% of classified bacteria were assigned in these 37 genera. Concordance by the two assays (presence/absence and correlations were high for common genera (Streptococcus, Veillonella, Leptotrichia, Prevotella, and Haemophilus; Correlation = 0.70-0.84. CONCLUSION: Microbiome community profiles assessed by 16S rRNA pyrosequencing and HOMIM were highly correlated at the phylum level and, when comparing the more commonly detected taxa, also at the genus level. Both methods are currently suitable for high-throughput epidemiologic investigations relating identified and more common oral microbial taxa to disease risk; yet, pyrosequencing may provide a broader spectrum of taxa identification, a distinct sequence-read record, and greater detection sensitivity.

  19. RPG: the Ribosomal Protein Gene database

    OpenAIRE

    Nakao, Akihiro; Yoshihama, Maki; Kenmochi, Naoya

    2004-01-01

    RPG (http://ribosome.miyazaki-med.ac.jp/) is a new database that provides detailed information about ribosomal protein (RP) genes. It contains data from humans and other organisms, including Drosophila melanogaster, Caenorhabditis elegans, Saccharo myces cerevisiae, Methanococcus jannaschii and Escherichia coli. Users can search the database by gene name and organism. Each record includes sequences (genomic, cDNA and amino acid sequences), intron/exon structures, genomic locations and informa...