105 research outputs found
Quail Genomics: a knowledgebase for Northern bobwhite
<p>Abstract</p> <p>Background</p> <p>The Quail Genomics knowledgebase (<url>http://www.quailgenomics.info</url>) has been initiated to share and develop functional genomic data for Northern bobwhite (<it>Colinus virginianus</it>). This web-based platform has been designed to allow researchers to perform analysis and curate genomic information for this non-model species that has little supporting information in GenBank.</p> <p>Description</p> <p>A multi-tissue, normalized cDNA library generated for Northern bobwhite was sequenced using 454 Life Sciences next generation sequencing. The Quail Genomics knowledgebase represents the 478,142 raw ESTs generated from the sequencing effort in addition to assembled nucleotide and protein sequences including 21,980 unigenes annotated with meta-data. A normalized MySQL relational database was established to provide comprehensive search parameters where meta-data can be retrieved using functional and structural information annotation such as gene name, pathways and protein domain. Additionally, blast hit cutoff levels and microarray expression data are available for batch searches. A Gene Ontology (GO) browser from Amigo is locally hosted providing 8,825 unigenes that are putative orthologs to chicken genes. In an effort to address over abundance of Northern bobwhite unigenes (71,384) caused by non-overlapping contigs and singletons, we have built a pipeline that generates scaffolds/supercontigs by aligning partial sequence fragments against the indexed protein database of chicken to build longer sequences that can be visualized in a web browser. </p> <p>Conclusion</p> <p>Our effort provides a central repository for storage and a platform for functional interrogation of the Northern bobwhite sequences providing comprehensive GO annotations, meta-data and a scaffold building pipeline. The Quail Genomics knowledgebase will be integrated with Japanese quail (<it>Coturnix coturnix</it>) data in future builds and incorporate a broader platform for these avian species. </p
The role of acyl-coenzyme A carboxylase complex in lipstatin biosynthesis of Streptomyces toxytricini
Streptomyces toxytricini produces lipstatin, a specific inhibitor of pancreatic lipase, which is derived from two fatty acid moieties with eight and 14 carbon atoms. The pccB gene locus in 10.6 kb fragment of S. toxytricini chromosomal DNA contains three genes for acyl-coenzyme A carboxylase (ACCase) complex accA3, pccB, and pccE that are presumed to be involved in secondary metabolism. The pccB gene encoding a β subunit of ACCase [carboxyltransferase (CT)] was identified upstream of pccE gene for a small protein of ε subunit. The accA3 encoding the α subunit of ACCase [biotin carboxylase (BC)] was also identified downstream of pccB gene. When the pccB and pccE genes were inactivated by homologous recombination, the lipstatin production was reduced as much as 80%. In contrast, the accumulation of another compound, tetradeca-5.8-dienoic acid (the major lipstatin precursor), was 4.5-fold increased in disruptant compared with wild-type. It implies that PccB of S. toxytricini is involved in the activation of octanoic acid to hexylmalonic acid for lipstatin biosynthesis
Analysis of synonymous codon usage in Hepatitis A virus
<p>Abstract</p> <p>Background</p> <p>Hepatitis A virus is the causative agent of type A viral hepatitis, which causes occasional acute hepatitis. Nevertheless, little information about synonymous codon usage pattern of HAV genome in the process of its evolution is available. In this study, the key genetic determinants of codon usage in HAV were examined.</p> <p>Results</p> <p>The overall extent of codon usage bias in HAV is high in <it>Picornaviridae</it>. And the patterns of synonymous codon usage are quite different in HAV genomes from different location. The base composition is closely correlated with codon usage bias. Furthermore, the most important determinant that results in such a high codon bias in HAV is mutation pressure rather than natural selection.</p> <p>Conclusions</p> <p>HAV presents a higher codon usage bias than other members of <it>Picornaviridae</it>. Compositional constraint is a significant element that influences the variation of synonymous codon usage in HAV genome. Besides, mutation pressure is supposed to be the major factor shaping the hyperendemic codon usage pattern of HAV.</p
The dpsA Gene of Streptomyces coelicolor: Induction of Expression from a Single Promoter in Response to Environmental Stress or during Development
The DpsA protein plays a dual role in Streptomyces coelicolor, both as part of the stress response and contributing to nucleoid condensation during sporulation. Promoter mapping experiments indicated that dpsA is transcribed from a single, sigB-like dependent promoter. Expression studies implicate SigH and SigB as the sigma factors responsible for dpsA expression while the contribution of other SigB-like factors is indirect by means of controlling sigH expression. The promoter is massively induced in response to osmotic stress, in part due to its sensitivity to changes in DNA supercoiling. In addition, we determined that WhiB is required for dpsA expression, particularly during development. Gel retardation experiments revealed direct interaction between apoWhiB and the dpsA promoter region, providing the first evidence for a direct WhiB target in S. coelicolor
Characterization of a putative NsrR homologue in Streptomyces venezuelae reveals a new member of the Rrf2 superfamily
Members of the Rrf2 superfamily of transcription factors are widespread in bacteria but their functions are largely unexplored. The few that have been characterized in detail sense nitric oxide (NsrR), iron limitation (RirA), cysteine availability (CymR) and the iron sulfur (Fe-S) cluster status of the cell (IscR). In this study we combined ChIP-seq with in vitro biochemistry to characterize a putative NsrR homologue in the model organism Streptomyces venezuelae. ChIP seq analysis revealed that rather than regulating the nitrosative stress response like NsrR, Sven6563 binds to a different, much larger regulon of genes with a diverse range of functions, including a range of regulators, genes required for glutamine synthesis, NADH/NAD(P)H metabolism, as well as general DNA/RNA and amino acid/protein turn over. Our biochemical experiments further show that Sven6563 has a [2Fe-2S] cluster and that the switch between oxidized and reduced cluster controls its DNA binding activity in vitro. To our knowledge, both the sensing domain and the target gene regulon are novel for an Rrf2 protein, suggesting Sven6563 represents a new member of the Rrf2 superfamily. Given the redox sensitivity of its Fe-S cluster we have tentatively named the protein RsrR for Redox sensitive response Regulator
A randomised controlled trial to compare opt-in and opt-out parental consent for childhood vaccine safety surveillance using data linkage: study protocol
Extent: 10p.Background: The Vaccine Assessment using Linked Data (VALiD) trial compared opt-in and opt-out parental consent for a population-based childhood vaccine safety surveillance program using data linkage. A subsequent telephone interview of all households enrolled in the trial elicited parental intent regarding the return or non-return of reply forms for opt-in and opt-out consent. This paper describes the rationale for the trial and provides an overview of the design and methods. Methods/Design: Single-centre, single-blind, randomised controlled trial (RCT) stratified by firstborn status. Mothers who gave birth at one tertiary South Australian hospital were randomised at six weeks post-partum to receive an opt-in or opt-out reply form, along with information explaining data linkage. The primary outcome at 10 weeks post-partum was parental participation in each arm, as indicated by the respective return or non-return of a reply form (or via telephone or email response). A subsequent telephone interview at 10 weeks post-partum elicited parental intent regarding the return or non-return of the reply form, and attitudes and knowledge about data linkage, vaccine safety, consent preferences and vaccination practices. Enrolment began in July 2009 and 1,129 households were recruited in a three-month period. Analysis has not yet been undertaken. The participation rate and selection bias for each method of consent will be compared when the data are analysed. Discussion: The VALiD RCT represents the first trial of opt-in versus opt-out consent for a data linkage study that assesses consent preferences and intent compared with actual opting in or opting out behaviour, and socioeconomic factors. The limitations to generalisability are discussed.Jesia G Berry, Philip Ryan, Annette J Braunack-Mayer, Katherine M Duszynski, Vicki Xafis, Michael S Gold, the Vaccine Assessment Using Linked Data (VALiD) Working Grou
Novel Two-Component Systems Implied in Antibiotic Production in Streptomyces coelicolor
The abundance of two-component systems (TCSs) in Streptomyces coelicolor A3(2) genome indicates their importance in the physiology of this soil bacteria. Currently, several TCSs have been related to antibiotic regulation, and the purpose in this study was the characterization of five TCSs, selected by sequence homology with the well-known absA1A2 system, that could also be associated with this important process. Null mutants of the five TCSs were obtained and two mutants (ΔSCO1744/1745 and ΔSCO4596/4597/4598) showed significant differences in both antibiotic production and morphological differentiation, and have been renamed as abr (antibiotic regulator). No detectable changes in antibiotic production were found in the mutants in the systems that include the ORFs SCO3638/3639, SCO3640/3641 and SCO2165/2166 in any of the culture conditions assayed. The system SCO1744/1745 (AbrA1/A2) was involved in negative regulation of antibiotic production, and acted also as a negative regulator of the morphological differentiation. By contrast, the system SCO4596/4597/4598 (AbrC1/C2/C3), composed of two histidine kinases and one response regulator, had positive effects on both morphological development and antibiotic production. Microarray analyses of the ΔabrC1/C2/C3 and wild-type transcriptomes revealed downregulation of actII-ORF4 and cdaR genes, the actinorhodin and calcium-dependent antibiotic pathway-specific regulators respectively. These results demonstrated the involvement of these new two-component systems in antibiotic production and morphological differentiation by different approaches. One is a pleiotropic negative regulator: abrA1/A2. The other one is a positive regulator composed of three elements, two histidine kinases and one response regulator: abrC1/C2/C3
Going against the herd: psychological and cultural factors underlying the 'vaccination confidence gap'
By far the most common strategy used in the attempt to modify negative attitudes toward vaccination is to appeal to evidence-based reasoning. We argue, however, that focusing on science comprehension is inconsistent with one of the key facts of cognitive psychology: Humans are biased information processors and often engage in motivated reasoning. On this basis, we hypothesised that negative attitudes can be explained primarily by factors unrelated to the empirical evidence for vaccination; including some shared attitudes that also attract people to complementary and alternative medicine (CAM). In particular, we tested psychosocial factors associated with CAM endorsement in past research; including aspects of spirituality, intuitive (vs analytic) thinking styles, and the personality trait of openness to experience. These relationships were tested in a cross-sectional, stratified CATI survey (N = 1256, 624 Females). Whilst educational level and thinking style did not predict vaccination rejection, psychosocial factors including: preferring CAM to conventional medicine (OR .49, 95% CI .36 .83, 95% CI .71 to vaccination. Furthermore, for 9 of the 12 CAMs surveyed, utilisation in the last 12 months was associated with lower levels of vaccination endorsement. From this we suggest that vaccination scepticism appears to be the outcome of a particular cultural and psychological orientation leading to unwillingness to engage with the scientific evidence. Vaccination compliance might be increased either by building general confidence and understanding of evidence-based medicine, or by appealing to features usually associated with CAM, e.g.–.66), endorsement of spirituality as a source of knowledge (OR–.96), and openness (OR .86, 95% CI .74–.99), all predicted negative attitudes‘strengthening your natural resistance to disease’
LAL Regulators SCO0877 and SCO7173 as Pleiotropic Modulators of Phosphate Starvation Response and Actinorhodin Biosynthesis in Streptomyces coelicolor
LAL regulators (Large ATP-binding regulators of the LuxR family) constitute a poorly studied family of transcriptional regulators. Several regulators of this class have been identified in antibiotic and other secondary metabolite gene clusters from actinomycetes, thus they have been considered pathway-specific regulators. In this study we have obtained two disruption mutants of LAL genes from S. coelicolor (Δ0877 and Δ7173). Both mutants were deficient in the production of the polyketide antibiotic actinorhodin, and antibiotic production was restored upon gene complementation of the mutants. The use of whole-genome DNA microarrays and quantitative PCRs enabled the analysis of the transcriptome of both mutants in comparison with the wild type. Our results indicate that the LAL regulators under study act globally affecting various cellular processes, and amongst them the phosphate starvation response and the biosynthesis of the blue-pigmented antibiotic actinorhodin. Both regulators act as negative modulators of the expression of the two-component phoRP system and as positive regulators of actinorhodin biosynthesis. To our knowledge this is the first characterization of LAL regulators with wide implications in Streptomyces metabolism
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