16S ribosomal RNA Dotaz Zobrazit nápovědu
A highly divergent 16S rRNA gene was found in one of the five ribosomal operons present in a species complex currently circumscribed as Scytonema hyalinum (Nostocales, Cyanobacteria) using clone libraries. If 16S rRNA sequence macroheterogeneity among ribosomal operons due to insertions, deletions or truncation is excluded, the sequence heterogeneity observed in S. hyalinum was the highest observed in any prokaryotic species thus far (7.3-9.0%). The secondary structure of the 16S rRNA molecules encoded by the two divergent operons was nearly identical, indicating possible functionality. The 23S rRNA gene was examined for a few strains in this complex, and it was also found to be highly divergent from the gene in Type 2 operons (8.7%), and likewise had nearly identical secondary structure between the Type 1 and Type 2 operons. Furthermore, the 16S-23S ITS showed marked differences consistent between operons among numerous strains. Both operons have promoter sequences that satisfy consensus requirements for functional prokaryotic transcription initiation. Horizontal gene transfer from another unknown heterocytous cyanobacterium is considered the most likely explanation for the origin of this molecule, but does not explain the ultimate origin of this sequence, which is very divergent from all 16S rRNA sequences found thus far in cyanobacteria. The divergent sequence is highly conserved among numerous strains of S. hyalinum, suggesting adaptive advantage and selective constraint of the divergent sequence.
- MeSH
- bakteriální RNA chemie genetika MeSH
- DNA bakterií genetika izolace a purifikace MeSH
- fylogeneze MeSH
- konformace nukleové kyseliny MeSH
- operon * MeSH
- promotorové oblasti (genetika) MeSH
- ribozomy metabolismus MeSH
- RNA ribozomální 16S chemie genetika MeSH
- sinice klasifikace genetika MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Environmental DNA and metabarcoding allow the identification of a mixture of species and launch a new era in bio- and eco-assessment. Many steps are required to obtain taxonomically assigned matrices from raw data. For most of these, a plethora of tools are available; each tool's execution parameters need to be tailored to reflect each experiment's idiosyncrasy. Adding to this complexity, the computation capacity of high-performance computing systems is frequently required for such analyses. To address the difficulties, bioinformatic pipelines need to combine state-of-the art technologies and algorithms with an easy to get-set-use framework, allowing researchers to tune each study. Software containerization technologies ease the sharing and running of software packages across operating systems; thus, they strongly facilitate pipeline development and usage. Likewise programming languages specialized for big data pipelines incorporate features like roll-back checkpoints and on-demand partial pipeline execution. FINDINGS: PEMA is a containerized assembly of key metabarcoding analysis tools that requires low effort in setting up, running, and customizing to researchers' needs. Based on third-party tools, PEMA performs read pre-processing, (molecular) operational taxonomic unit clustering, amplicon sequence variant inference, and taxonomy assignment for 16S and 18S ribosomal RNA, as well as ITS and COI marker gene data. Owing to its simplified parameterization and checkpoint support, PEMA allows users to explore alternative algorithms for specific steps of the pipeline without the need of a complete re-execution. PEMA was evaluated against both mock communities and previously published datasets and achieved results of comparable quality. CONCLUSIONS: A high-performance computing-based approach was used to develop PEMA; however, it can be used in personal computers as well. PEMA's time-efficient performance and good results will allow it to be used for accurate environmental DNA metabarcoding analysis, thus enhancing the applicability of next-generation biodiversity assessment studies.
- MeSH
- Archaea MeSH
- Bacteria MeSH
- environmentální DNA chemie genetika MeSH
- houby MeSH
- metagenomika metody normy MeSH
- referenční standardy MeSH
- respirační komplex IV genetika MeSH
- RNA ribozomální 16S genetika MeSH
- RNA ribozomální 18S genetika MeSH
- rostliny MeSH
- senzitivita a specificita MeSH
- software MeSH
- taxonomické DNA čárové kódování metody normy MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Frameshifting of mRNA during translation provides a strategy to expand the coding repertoire of cells and viruses. How and where in the elongation cycle +1-frameshifting occurs remains poorly understood. We describe seven ~3.5-Å-resolution cryo-EM structures of 70S ribosome complexes, allowing visualization of elongation and translocation by the GTPase elongation factor G (EF-G). Four structures with a + 1-frameshifting-prone mRNA reveal that frameshifting takes place during translocation of tRNA and mRNA. Prior to EF-G binding, the pre-translocation complex features an in-frame tRNA-mRNA pairing in the A site. In the partially translocated structure with EF-G•GDPCP, the tRNA shifts to the +1-frame near the P site, rendering the freed mRNA base to bulge between the P and E sites and to stack on the 16S rRNA nucleotide G926. The ribosome remains frameshifted in the nearly post-translocation state. Our findings demonstrate that the ribosome and EF-G cooperate to induce +1 frameshifting during tRNA-mRNA translocation.
- MeSH
- biokatalýza MeSH
- elektronová kryomikroskopie MeSH
- elongace translace peptidového řetězce genetika MeSH
- elongační faktor G chemie genetika metabolismus MeSH
- Escherichia coli genetika metabolismus MeSH
- konformace nukleové kyseliny MeSH
- konformace proteinů MeSH
- messenger RNA chemie genetika metabolismus MeSH
- molekulární modely MeSH
- posun čtecího rámce na ribozómech genetika MeSH
- proteiny z Escherichia coli chemie genetika metabolismus MeSH
- ribozomy genetika metabolismus ultrastruktura MeSH
- RNA ribozomální 16S chemie genetika metabolismus MeSH
- RNA transferová chemie genetika metabolismus MeSH
- tRNA-methyltransferasy genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
The role of 16S rRNA has been and largely remains crucial for the identification of microbial organisms. Although 16S rRNA could certainly be described as one of the most studied sequences ever, the current view of it remains somewhat ambiguous. While some consider 16S rRNA to be a variable marker with resolution power down to the strain level, others consider them to be living fossils that carry information about the origin of domains of cellular life. We show that 16S rRNA is clearly an evolutionarily very rigid sequence, making it a largely unique and irreplaceable marker, but its applicability beyond the genus level is highly limited. Interestingly, it seems that the evolutionary rigidity is not driven by functional constraints of the sequence (RNA-protein interactions), but rather results from the characteristics of the host organism. Our results suggest that, at least in some lineages, Horizontal Gene Transfer (HGT) within genera plays an important role for the evolutionary non-dynamics (stasis) of 16S rRNA. Such genera exhibit an apparent lack of diversification at the 16S rRNA level in comparison to the rest of a genome. However, why it is limited specifically and solely to 16S rRNA remains enigmatic.
- MeSH
- biologická evoluce * MeSH
- fylogeneze MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční analýza DNA MeSH
- Publikační typ
- časopisecké články MeSH
The Asian citrus psyllid Diaphorina citri (Hemiptera: Psylloidea) is a serious pest of citrus species worldwide because it transmits Candidatus Liberibacter spp. (Alphaproteobacteria: Rhizobiales), the causative agents of the incurable citrus disease, huanglongbing or greening disease. Diaphorina citri possesses a specialized organ called a bacteriome, which harbors vertically transmitted intracellular mutualists, Ca. Carsonella ruddii (Gammaproteobacteria: Oceanospirillales) and Ca. Profftella armatura (Gammaproteobacteria: Betaproteobacteriales). Whereas Carsonella is a typical nutritional symbiont, Profftella is an unprecedented type of toxin-producing defensive symbiont, unusually sharing organelle-like features with nutritional symbionts. Additionally, many D. citri strains are infected with Wolbachia, which manipulate reproduction in various arthropod hosts. In the present study, in an effort to obtain insights into the evolution of symbioses between Diaphorina and bacteria, microbiomes of psyllids closely related to D. citri were investigated. Bacterial populations of Diaphorina cf. continua and Diaphorina lycii were analyzed using Illumina sequencing of 16S rRNA gene amplicons and compared with data obtained from D. citri. The analysis revealed that all three Diaphorina spp. harbor Profftella as well as Carsonella lineages, implying that Profftella is widespread within the genus Diaphorina. Moreover, the analysis identified Ca. Liberibacter europaeus and Diplorickettsia sp. (Gammaproteobacteria: Diplorickettsiales) in D. cf. continua, and a total of four Wolbachia (Alphaproteobacteria: Rickettsiales) lineages in the three psyllid species. These results provide deeper insights into the interactions among insects, bacteria, and plants, which would eventually help to better manage horticulture.
- MeSH
- Bacteria klasifikace izolace a purifikace MeSH
- bakteriální RNA analýza MeSH
- Hemiptera mikrobiologie MeSH
- RNA ribozomální 16S analýza MeSH
- symbióza MeSH
- Wolbachia izolace a purifikace MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Francie MeSH
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.
- MeSH
- Burkholderiaceae genetika izolace a purifikace MeSH
- DNA bakterií genetika MeSH
- ekologie MeSH
- ekosystém MeSH
- fylogeneze MeSH
- genomika * MeSH
- plankton genetika izolace a purifikace MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční analýza DNA MeSH
- sladká voda mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
In this study, we addressed differences in the development of gut microbiota in 4 successive batches of commercially hatched broiler parent chickens. When planning this study, we expected to find a batch with compromised performance which would allow identification of microbiota of suboptimal composition. Microbiota composition was determined only by sequencing the V3/V4 region of 16S rRNA genes in samples collected from chickens 5 to 18 wk of age. In a total, 100 and 160 samples originating from the ileum or cecum were processed, respectively. In one of the flocks with suboptimal performance we identified an increased abundance of Helicobacter brantae forming over 80% of ileal microbiota in individual chickens. Moreover, we also tested samples of 53-wk-old hens from the same genetic line in which egg production decreased. In this case, cecal microbiota was enriched for Fusobacterium mortiferum forming over 30% of total cecal microbiota. Although none of the identified unusual microbiota members have been well recognized as pathogenic, they may represent new opportunistic pathogens of chickens worth of further investigation. Analysis of gut microbiota composition by next generation sequencing thus proved as a useful and unbiased alternative to bacterial culture, especially in the cases of unspecific symptoms like decrease in flock performance.
- MeSH
- Bacteria klasifikace izolace a purifikace MeSH
- bakteriální RNA analýza MeSH
- cékum mikrobiologie MeSH
- Fusobacterium izolace a purifikace MeSH
- Helicobacter izolace a purifikace MeSH
- ileum mikrobiologie MeSH
- kur domácí mikrobiologie MeSH
- RNA ribozomální 16S analýza MeSH
- sekvenční analýza RNA veterinární MeSH
- střevní mikroflóra * MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Electronic waste is an evolving source of harmful pollutants in our surrounding environments and considered to be perilous as it contains toxic metals such as chromium, cadmium, lead, mercury, zinc, and nickel in huge quantities. Heavy metals are harmful contaminants and accumulated in the environment due to various anthropogenic activities. The present study was conducted to isolate and characterize different heavy metal tolerant bacterial species, based on molecular techniques from soil contaminated by electronic waste. The contaminated soil samples were analyzed for various physicochemical properties such as pH, electrical conductivity, soil moisture, water holding capacity, organic carbon, organic matter, available phosphorus, total nitrogen, and potassium using standard procedures. The soil samples were found to contain a higher amount of different heavy metals such as copper, chromium, lead, iron, cadmium, and nickel. Serial dilution and spread plate techniques have been used for bacterial isolation. The identification and molecular characterization of isolated bacterial species were done by biochemical tests and 16S rRNA gene sequencing technique. The 16S rRNA sequencing analysis confirmed the presence of different bacterial species as, Micrococcus aloeverae, Kocuria turfanensis, Bacillus licheniformis, Bacillus jeotgali, Bacillus velezensis, and Bacillus haikouensis. The findings indicated that the e-waste dumping sites are the storehouse of elite bacterial species. The present research study offers a platform for systematic analysis of e-waste sites by microbial profiling that may help in the innovation of novel microorganisms of scientific importance and better biotechnological potential.
- MeSH
- Bacteria klasifikace účinky léků genetika izolace a purifikace MeSH
- DNA bakterií MeSH
- elektronický odpad analýza MeSH
- genom bakteriální MeSH
- látky znečišťující půdu analýza MeSH
- monitorování životního prostředí MeSH
- půda chemie MeSH
- půdní mikrobiologie * MeSH
- RNA ribozomální 16S genetika MeSH
- těžké kovy toxicita MeSH
- Publikační typ
- časopisecké články MeSH
The 16S-23S ribosomal internal transcribed spacer (ITS1) is often used as a subspecies or strain-specific molecular marker for various kinds of bacteria. However, the presence of different copies of ITS1 within a single genome has been reported. Such mosaicism may influence correct typing of many bacteria and therefore knowledge about exact configuration of this region in a particular genome is essential. In order to screen the variability of ITS1 among and within Pseudomonas syringae genomes, an oligonucleotide microarray targeting different configurations of ITS1 was developed. The microarray revealed seven distinct variants in 13 pathovars tested and detected mosaicism within the genomes of P. syringae pv. coronafaciens, pisi, syringae and tabaci. In addition, the findings presented here challenge the using of rRNA analysis for pathovar and strain determination.
- MeSH
- DNA bakterií genetika MeSH
- fylogeneze MeSH
- genetická variace MeSH
- mezerníky ribozomální DNA genetika MeSH
- molekulární sekvence - údaje MeSH
- nemoci rostlin mikrobiologie MeSH
- Pseudomonas syringae klasifikace genetika izolace a purifikace MeSH
- RNA ribozomální 16S genetika MeSH
- RNA ribozomální 23S genetika MeSH
- rostliny mikrobiologie MeSH
- sekvence nukleotidů MeSH
- sekvenční analýza hybridizací s uspořádaným souborem oligonukleotidů metody MeSH
- sekvenční seřazení MeSH
- techniky typizace bakterií MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH