Phylogenetic placement of unculturedCeanothusmicrosymbionts using 16S rRNA gene sequences

1999 ◽  
Vol 77 (9) ◽  
pp. 1208-1213 ◽  
Author(s):  
Nancy J Ritchie ◽  
David D Myrold
Keyword(s):  
16S Rdna ◽  
Phylogenetic Trees ◽  
Full Length ◽  
Likelihood Method ◽  
Rrna Gene ◽  
Consensus Sequences ◽  
Rdna Sequences ◽  
16S Rdna Sequences ◽  
Polymerase Chain ◽  
Ceanothus Americanus

Full-length 16S rDNA sequences were amplified directly from the nodules of Ceanothus americanus L. and Ceanothus thyrsiflorus Eschsch. using the polymerase chain reaction. Sequences were determined using an automated sequencer, compared against those in GenBank, and assembled into consensus sequences. The sequences were aligned with other full-length Frankia 16S rDNA sequences available from the data base. Phylogenetic trees were obtained using three different algorithms: neighbor joining, parsimony, and the maximum-likelihood method. All three methods showed that these Ceanothus L. microsymbionts were most closely related to the microsymbiont associated with Dryas drummondii Richardson ex Hook. Lvs. rather than Frankia isolated from the Elaeagnaceae.Key words: Frankia, Ceanothus, 16S rDNA.

scholarly journals Erigeron Witches'-Broom Phytoplasma in Brazil Represents New Subgroup VII-B in 16S rRNA Gene Group VII, the Ash Yellows Phytoplasma Group

Plant Disease ◽  
2002 ◽  
Vol 86 (10) ◽  
pp. 1142-1148 ◽  
Author(s):  
Thereza S. L. Barros ◽  
Robert E. Davis ◽  
Renato O. Resende ◽  
Ellen L. Dally
Keyword(s):  
16S Rdna ◽  
Fragment Length Polymorphism ◽  
Rflp Analysis ◽  
Rrna Gene ◽  
Chain Reaction ◽  
Gene Group ◽  
Rdna Sequences ◽  
16S Rdna Sequences ◽  
Polymerase Chain ◽  
Restriction Fragment Length

A previously undescribed phytoplasma, Erigeron witches'-broom phytoplasma, was detected in diseased plants of Erigeron sp. and Catharanthus roseus exhibiting symptoms of witches'-broom and chlorosis in the state of São Paulo, Brazil. On the basis of restriction fragment length polymorphism (RFLP) analysis of 16S rDNA amplified in the polymerase chain reaction (PCR), Erigeron witches'-broom phytoplasma was classified in group 16SrVII (ash yellows phytoplasma group), new subgroup VII-B. Phylogenetic analysis of 16S rDNA sequences indicated that this phytoplasma represents a new lineage that is distinct from that of described strains of ash yellows phytoplasma. Erigeron witches'-broom phytoplasma is the first member of the ash yellows phytoplasma group to be recorded in Brazil.

Systematic position of Dinidoridae within the superfamily Pentatomoidea (Hemiptera: Heteroptera) revealed by the Bayesian phylogenetic analysis of the mitochondrial 12S and 16S rDNA sequences

Zootaxa ◽  
2012 ◽  
Vol 3423 (1) ◽  
pp. 61 ◽  
Author(s):  
JERZY A. LIS ◽  
PAWEŁ LIS ◽  
DARIUSZ J. ZIAJA ◽  
ANNA KOCOREK
Keyword(s):  
16S Rdna ◽  
Phylogenetic Trees ◽  
Taxonomic Status ◽  
Sister Group ◽  
Systematic Position ◽  
Bayesian Phylogenetic Analysis ◽  
Rdna Sequences ◽  
16S Rdna Sequences ◽  
Molecular Affinity ◽  
The Moment

Mitochondrial 12S and 16S rDNA sequences of five species of Dinidoridae Stål, 1868, a largely Paleotropical family, and 16 other shield bugs (Pentatomoidea) were studied. This was the first molecular examination of the systematic position of this family within the superfamily Pentatomoidea using more than a single dinidorid species. Phylogenetic trees obtained from the Bayesian inference of 12S and 16S sequences of these mitochondrial DNA, identified Dinidoridae as the monophylum and a sister group to the Tessaratomidae. Moreover, results of the study suggested a close molecular affinity of the genus Eumenotes to representatives of the subfamily Dinidorinae, which contradicts all previous morphological analyses that placed it within the subfamily Megymeninae. We suggest restoring taxonomic status of the tribe Eumenotini and removing it from the synonymy of Megymenini, leaving the genus with no subfamilial assignment for the moment.

scholarly journals Phenotypic characterization of Astragalus glycyphyllos symbionts and their phylogeny based on the 16S rDNA sequences and RFLP of 16S rRNA gene

2014 ◽  
Vol 105 (6) ◽  
pp. 1033-1048 ◽  
Author(s):  
Sebastian Gnat ◽  
Magdalena Wójcik ◽  
Sylwia Wdowiak-Wróbel ◽  
Michał Kalita ◽  
Aneta Ptaszyńska ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
16S Rdna ◽  
Phenotypic Characterization ◽  
Rrna Gene ◽  
Rdna Sequences ◽  
16S Rdna Sequences ◽  
Astragalus Glycyphyllos Symbionts

scholarly journals Phylogenetic Analysis of Nonthermophilic Members of the Kingdom Crenarchaeota and Their Diversity and Abundance in Soils

1998 ◽  
Vol 64 (11) ◽  
pp. 4333-4339 ◽  
Author(s):  
Daniel H. Buckley ◽  
Joseph R. Graber ◽  
Thomas M. Schmidt
Keyword(s):  
16S Rrna ◽  
16S Rdna ◽  
Phylogenetic Analyses ◽  
Pcr Primers ◽  
Soil Samples ◽  
Molecular Techniques ◽  
Rrna Gene ◽  
Rdna Sequences ◽  
16S Rdna Sequences ◽  
Long Term Ecological Research

ABSTRACT Within the last several years, molecular techniques have uncovered numerous 16S rRNA gene (rDNA) sequences which represent a unique and globally distributed lineage of the kingdom Crenarchaeotathat is phylogenetically distinct from currently characterized crenarchaeotal species. rDNA sequences of members of this novel crenarchaeotal group have been recovered from low- to moderate-temperature environments (−1.5 to 32°C), in contrast to the high-temperature environments (temperature, >80°C) required for growth of the currently recognized crenarchaeotal species. We determined the diversity and abundance of the nonthermophilic members of the Crenarchaeota in soil samples taken from cultivated and uncultivated fields located at the Kellogg Biological Station’s Long-Term Ecological Research site (Hickory Corners, Mich.). Clones were generated from 16S rDNA that was amplified by using broad-specificity archaeal PCR primers. Twelve crenarchaeotal sequences were identified, and the phylogenetic relationships between these sequences and previously described crenarchaeotal 16S rDNA sequences were determined. Phylogenetic analyses included nonthermophilic crenarchaeotal sequences found in public databases and revealed that the nonthermophilic Crenarchaeota group is composed of at least four distinct phylogenetic clusters. A 16S rRNA-targeted oligonucleotide probe specific for all known nonthermophilic crenarchaeotal sequences was designed and used to determine their abundance in soil samples. The nonthermophilicCrenarchaeota accounted for as much as 1.42% ± 0.42% of the 16S rRNA in the soils analyzed.

scholarly journals TaxaSE: Exploiting evolutionary conservation within 16S rDNA sequences for enhanced taxonomic annotation

2017 ◽  
Author(s):  
Ali Z Ijaz ◽  
Thomas Jeffries ◽  
Christopher Quince ◽  
Kelly Hamonts ◽  
Brajesh Singh
Keyword(s):  
16S Rdna ◽  
Sequence Similarity ◽  
Marker Gene ◽  
Evolutionary Conservation ◽  
Rrna Gene ◽  
Similarity Metric ◽  
Rdna Sequences ◽  
Fine Grain ◽  
16S Rdna Sequences ◽  
Taxonomic Annotation

Amplicon based taxonomic analysis, which determines the presence of microbial taxa in different environments on the basis of marker gene annotations, often uses percentage identity as the main metric to determine sequence similarity against databases. These data are then used to study the distribution of biodiversity as well as response of microbial communities to environmental conditions. However the 16S rRNA gene displays varying degrees of sequence conservation along its length and percentage identity does not fully utilize this information. Additionally, the prevalent usage of Operational Taxonomic Unit, or OTUs is not without its own issues and may lead to a reduction in annotation capability of the system. Hence a novel approach to taxonomic annotation is needed. Here we introduce a new taxonomic annotation pipeline, TaxaSE, which utilizes Shannon entropy to quantify evolutionary conservation within 16S rDNA sequences for enhanced taxonomic annotations. Furthermore, the system is capable of annotation of individual sequences in order to improve fine grain taxonomic annotations. We present both in-silico comparison of the new similarity metric with percentage identity, as well as comparison with the popular QIIME pipeline. The results demonstrate the new similarity metric achieves better performance especially at lower taxa levels. Furthermore, the pipeline is able to extract more fine grain taxonomic annotations compared to QIIME. These exhibit not only the effectiveness of the new pipeline but also highlight the need to shift away from both percentage identity and OTU based approaches for ecological projects.

scholarly journals First Report of a Group 16SrI-B Phytoplasma Associated with Gardenia jasminoides in China

Plant Disease ◽  
2012 ◽  
Vol 96 (10) ◽  
pp. 1576-1576 ◽  
Author(s):  
X. C. Sun ◽  
W. J. Zhao
Keyword(s):  
16S Rdna ◽  
Nested Pcr ◽  
Consensus Sequence ◽  
Rrna Gene ◽  
Reference Pattern ◽  
Green Belt ◽  
First Report ◽  
Rdna Sequences ◽  
Gardenia Jasminoides ◽  
16S Rdna Sequences

Gardenia jasminoides J. Ellis, (also known as common gardenia, cape jasmine, or cape jessamine) is a fragrant flowering evergreen tropical plant, a favorite in gardens worldwide. G. jasminoides were found with small, seriously yellowed leaves, stunted growth, and witches'-broom in a green belt on the Southwest University campus in October 2011. The incidence was lower than 2%. In another green belt, G. jasminoides with only slightly yellowing leaves were found. The incidence was about 5%. Five months later, most seriously yellowed leaves withered. However, no withered leaf was observed among the slightly yellowing leaves. Leaf samples from each symptomatic plant, together with asymptomatic plants from the same belt, were collected for total DNA extraction using a modified cetyltrimethylammoniumbromide method (1). The resulting DNA extracts were analyzed by a nested PCR assay using the phytoplasma 16S rRNA gene primer pairs R16mF2/R16mR1 followed by R16F2n/R16R2 (2). DNA fragments of 1.2 kb that corresponded to 16S rDNA were amplified only from the DNA samples of the five plants with the symptoms mentioned above. The purified nested PCR products were cloned in pGEM-T Easy Vector (Promega) and then sequenced. The resulting 16S rDNA sequences were found to be identical (GenBank Accession No. JQ675713). The consensus sequence was analyzed by the iPhyClassifier online tool ( http://plantpathology.ba.ars.usda.gov/cgi-bin/resource/iphyclassifier.cgi ) and found to share 99.4% similarity with the 16S rDNA sequence of the ‘Candidatus Phytoplasma asteris’ reference strain (GenBank Accession No. M30790) that belongs to the 16SrI-B subgroup (3). The virtual RFLP pattern of the G. jasminoides phytoplasma 16S rDNA gene sequence showed maximum similarity to the reference pattern of NC005303 (similarity coefficient of 1.0). The phylogenetic tree based on the 16S rDNA sequences of phytoplasmas belonging to group 16SrI and other distinct phytoplasma groups also showed that our sequences clustered with members of subgroup 16SrI-B. Subsequently, the presence of the phytoplasmas in symptomatic plants was also confirmed by transmission electron microscopy. Taken together, the phytoplasma was classified as a member of subgroup 16SrI-B. To our knowledge, this is the first report of a subgroup 16SrI-B phytoplasma associated with diseased G. jasminoides in China. G. jasminoides yellowing is often considered to result from nutrient deficiency (especially iron compounds). However, our findings showed that a phytoplasma can cause G. jasminoides yellowing, which should be considered in the control of leaves yellowing. References: (1) E. Angelini et al. Vitis 40:79, 2001. (2) D. E. Gundersen and I.-M. Lee. Phytopathol. Mediterr. 35:144, 1996. (3) Y. Zhao, et al. Int. J. Syst. Evol. Microbiol. 59:2582, 2009.

scholarly journals Effects of 16S rDNA sampling on estimates of endosymbiont lineages in sucking lice

2015 ◽  
Author(s):  
Julie M Allen ◽  
J Gordon Burleigh ◽  
Jessica E Light ◽  
David L Reed
Keyword(s):  
16S Rdna ◽  
Phylogenetic Trees ◽  
Sampling Strategies ◽  
Host Group ◽  
Rdna Sequences ◽  
Endosymbiotic Bacteria ◽  
16S Rdna Sequences ◽  
Evolutionary Inference ◽  
Sucking Lice ◽  
Diversity Sampling

Co-evolution between insects and their endosymbiotic bacteria can be detected by constructing and comparing their phylogenetic trees. Even though taxon sampling can greatly affect phylogenetic and co-evolutionary inference, most hypotheses of endosymbiont relationships and estimates of the number of endosymbiont lineages within a host group have used only a small percentage of 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. We found that sampling of 16S rDNA sequences affected the estimates of endosymbiont diversity in sucking lice until we reached a threshold of genetic diversity. Sampling by maximizing the diversity of 16S rDNA sequences was more efficient than simply randomly sampling available 16S rDNA sequences. Although simulation results support the finding of multiple endosymbiont lineages in sucking lice, the bootstrap results suggest that there is still uncertainty in estimates of the number of endosymbiont origins inferred from 16S rDNA alone.

scholarly journals In Situ Detection of Novel Bacterial Endosymbionts of Acanthamoeba spp. Phylogenetically Related to Members of the Order Rickettsiales

1999 ◽  
Vol 65 (1) ◽  
pp. 206-212 ◽  
Author(s):  
Thomas R. Fritsche ◽  
Matthias Horn ◽  
Seyedreza Seyedirashti ◽  
Romesh K. Gautom ◽  
Karl-Heinz Schleifer ◽  
...  
Keyword(s):  
16S Rdna ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Rrna Gene ◽  
Oligonucleotide Probes ◽  
Gram Negative ◽  
Rdna Sequences ◽  
16S Rdna Sequences ◽  
Bacterial Endosymbionts

ABSTRACT Acanthamoebae are ubiquitous soil and water bactivores which may serve as amplification vehicles for a variety of pathogenic facultative bacteria and as hosts to other, presently uncultured bacterial endosymbionts. The spectrum of uncultured endosymbionts includes gram-negative rods and gram-variable cocci, the latter recently shown to be members of the Chlamydiales. We report here the isolation from corneal scrapings of two Acanthamoebastrains that harbor gram-negative rod endosymbionts that could not be cultured by standard techniques. These bacteria were phylogenetically characterized following amplification and sequencing of the near-full-length 16S rRNA gene. We used two fluorescently labelled oligonucleotide probes targeting signature regions within the retrieved sequences to detect these organisms in situ. Phylogenetic analyses demonstrated that they displayed 99.6% sequence similarity and formed an independent and well-separated lineage within theRickettsiales branch of the alpha subdivision of theProteobacteria. Nearest relatives included members of the genus Rickettsia, with sequence similarities of approximately 85 to 86%, suggesting that these symbionts are representatives of a new genus and, perhaps, family. Distance matrix, parsimony, and maximum-likelihood tree-generating methods all consistently supported deep branching of the 16S rDNA sequences within the Rickettsiales. The oligonucleotide probes displayed at least three mismatches to all other available 16S rDNA sequences, and they both readily permitted the unambiguous detection of rod-shaped bacteria within intact acanthamoebae by confocal laser-scanning microscopy. Considering the long-standing relationship of mostRickettsiales with arthropods, the finding of a related lineage of endosymbionts in protozoan hosts was unexpected and may have implications for the preadaptation and/or recruitment of rickettsia-like bacteria to metazoan hosts.

scholarly journals Further refinement of the phylogeny of the Halobacteriaceae based on the full-length RNA polymerase subunit B′ (rpoB′) gene

2010 ◽  
Vol 60 (10) ◽  
pp. 2398-2408 ◽  
Author(s):  
Hiroaki Minegishi ◽  
Masahiro Kamekura ◽  
Takashi Itoh ◽  
Akinobu Echigo ◽  
Ron Usami ◽  
...  
Keyword(s):  
Rna Polymerase ◽  
Phylogenetic Trees ◽  
Gene Tree ◽  
Amino Acid Sequences ◽  
Full Length ◽  
Likelihood Method ◽  
Sequence Length ◽  
Rrna Gene ◽  
B Subunit ◽  
Protein Tree

A considerable number of species of the Halobacteriaceae possess multiple copies of the 16S rRNA gene that exhibit more than 5 % divergence, complicating phylogenetic interpretations. Two additional problems have been pointed out: (i) the genera Haloterrigena and Natrinema show a very close relationship, with some species being shown to overlap in phylogenetic trees reconstructed by the neighbour-joining method, and (ii) alkaliphilic and neutrophilic species of the genus Natrialba form definitely separate clusters in neighbour-joining trees, suggesting that these two clusters could be separated into two genera. In an attempt to solve these problems, the RNA polymerase B′ subunit has been used as an additional target molecule for phylogenetic analysis, using partial sequences of 1305 bp. In this work, a primer set was designed that consistently amplified the full-length RNA polymerase B′ subunit gene (rpoB′) (1827–1842 bp) from 85 strains in 27 genera of the Halobacteriaceae. Differences in sequence length were found within the first 15 to 31 nt, and their downstream sequences (1812 bp) were aligned unambiguously without any gaps or deletions. Phylogenetic trees reconstructed from nucleotide sequences and deduced amino acid sequences by the maximum-likelihood method demonstrated that multiple species/strains in most genera individually formed cohesive clusters. Two discrepancies were observed: (i) the two species of Natronolimnobius were placed in definitely different positions, in that Natronolimnobius innermongolicus was placed in the Haloterrigena/Natrinema cluster, while Natronolimnobius baerhuensis was closely related to Halostagnicola larsenii, and (ii) Natronorubrum tibetense was segregated from the three other Natronorubrum species in the protein tree, while all four species formed a cluster in the gene tree, although supported by a bootstrap value of less than 50 %. The six Haloterrigena species/strains and the five species of Natrinema formed a large cluster in both trees, with Halopiger xanaduensis and Nln. innermongolicus located in the cluster in the protein tree and Nln. innermongolicus in the gene tree. Hpg. xanaduensis broke into the cluster of the genus Halobiforma, instead of the Haloterrigena/Natrinema cluster, in the gene tree. The six Natrialba species formed a tight cluster with two subclusters, of neutrophilic species and alkaliphilic species, in both trees. Overall, our data strongly suggest that (i) Nln. innermongolicus is a member of Haloterrigena/Natrinema, (ii) Nrr. tibetense might represent a new genus and (iii) the two genera Haloterrigena and Natrinema might constitute a single genus. As more and more novel species and genera are proposed in the family Halobacteriaceae, the full sequence of the rpoB′ gene may provide a supplementary tool for determining the phylogenetic position of new isolates.

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