scholarly journals Genome-Wide Transcriptional Changes in Streptococcus gordonii in Response to Competence Signaling Peptide

2007 ◽  
Vol 189 (21) ◽  
pp. 7799-7807 ◽  
Author(s):  
M. M. Vickerman ◽  
S. Iobst ◽  
A. M. Jesionowski ◽  
S. R. Gill
Keyword(s):  
Transcriptional Response ◽  
Streptococcus Gordonii ◽  
Direct Repeats ◽  
Multispecies Biofilm ◽  
Genome Wide ◽  
A Genome ◽  
Tooth Surfaces ◽  
Transcriptional Changes ◽  
Species Specific ◽  
Regulatory Sites

ABSTRACT Streptococcus gordonii is a primary colonizer of the multispecies biofilm on tooth surfaces forming dental plaque and a potential agent of endocarditis. The recent completion of the genome sequence of the naturally competent strain Challis allowed the design of a spotted oligonucleotide microarray to examine a genome-wide response of this organism to environmental stimuli such as signal peptides. Based on temporal responses to synthetic competence signaling peptide (CSP) as indicated by transformation frequencies, the S. gordonii transcriptome was analyzed at various time points after CSP exposure. Microarray analysis identified 35 candidate early genes and 127 candidate late genes that were up-regulated at 5 and 15 min, respectively; these genes were often grouped in clusters. Results supported published findings on S. gordonii competence, showing up-regulation of 12 of 16 genes that have been reported to affect transformation frequencies in this species. Comparison of CSP-induced S. gordonii transcriptomes to results published for Streptococcus pneumoniae strains identified both conserved and species-specific genes. Putative intergenic regulatory sites, such as the conserved combox sequence thought to be a binding site for competence sigma factor, were found preceding S. gordonii late responsive genes. In contrast, S. gordonii early CSP-responsive genes were not preceded by the direct repeats found in S. pneumoniae. These studies provide the first insights into a genome-wide transcriptional response of an oral commensal organism. They offer an extensive analysis of transcriptional changes that accompany competence in S. gordonii and form a basis for future intra- and interspecies comparative analyses of this ecologically important phenotype.

scholarly journals KLF4 binding is involved in the organization and regulation of 3D enhancer networks during acquisition and maintenance of pluripotency

2018 ◽  
Author(s):  
Dafne Campigli Di Giammartino ◽  
Andreas Kloetgen ◽  
Alexander Polyzos ◽  
Yiyuan Liu ◽  
Daleum Kim ◽  
...  
Keyword(s):  
Cell Fate ◽  
Binding Sites ◽  
Target Gene ◽  
Embryonic Fibroblasts ◽  
Molecular Events ◽  
Genome Wide ◽  
A Genome ◽  
Integrative View ◽  
Transcriptional Changes ◽  
Complex Activities

SUMMARYCell fate transitions are accompanied by global transcriptional, epigenetic and topological changes driven by transcription factors (TFs), as is strikingly exemplified by reprogramming somatic cells to pluripotent stem cells (PSCs) via expression of OCT4, KLF4, SOX2 and cMYC. How TFs orchestrate the complex molecular changes around their target gene loci in a temporal manner remains incompletely understood. Here, using KLF4 as a paradigm, we provide the first TF-centric view of chromatin reorganization and its association to 3D enhancer rewiring and transcriptional changes of linked genes during reprogramming of mouse embryonic fibroblasts (MEFs) to PSCs. Inducible depletion of KLF factors in PSCs caused a genome-wide decrease in the connectivity of enhancers, while disruption of individual KLF4 binding sites from PSC-specific enhancers was sufficient to impair enhancer-promoter contacts and reduce expression of associated genes. Our study provides an integrative view of the complex activities of a lineage-specifying TF during a controlled cell fate transition and offers novel insights into the order and nature of molecular events that follow TF binding.

scholarly journals Integrative analysis of epigenetics data identifies gene-specific regulatory elements

2019 ◽  
Author(s):  
Florian Schmidt ◽  
Alexander Marx ◽  
Marie Hebel ◽  
Martin Wegner ◽  
Nina Baumgarten ◽  
...  
Keyword(s):  
Transcriptional Regulation ◽  
Cell Types ◽  
Regulatory Elements ◽  
Chromatin Accessibility ◽  
Genome Wide ◽  
A Genome ◽  
Gene Level ◽  
Regulatory Landscape ◽  
Regulatory Sites ◽  
Validation Experiments

AbstractUnderstanding the complexity of transcriptional regulation is a major goal of computational biology. Because experimental linkage of regulatory sites to genes is challenging, computational methods considering epigenomics data have been proposed to create tissue-specific regulatory maps. However, we showed that these approaches are not well suited to account for the variations of the regulatory landscape between cell-types. To overcome these drawbacks, we developed a new method called STITCHIT, that identifies and links putative regulatory sites to genes. Within STITCHIT, we consider the chromatin accessibility signal of all samples jointly to identify regions exhibiting a signal variation related to the expression of a distinct gene. STITCHIToutperforms previous approaches in various validation experiments and was used with a genome-wide CRISPR-Cas9 screen to prioritize novel doxorubicin-resistance genes and their associated non-coding regulatory regions. We believe that our work paves the way for a more refined understanding of transcriptional regulation at the gene-level.

Genotypic variation of gene expression during the soybean innate immunity response

2014 ◽  
Vol 12 (S1) ◽  
pp. S27-S30 ◽  
Author(s):  
Oswaldo Valdés-López ◽  
Saad M. Khan ◽  
Robert J. Schmitz ◽  
Shiqi Cui ◽  
Jing Qiu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Innate Immunity ◽  
Plant Species ◽  
Genotypic Variation ◽  
Additive Effects ◽  
Molecular Pattern ◽  
Genome Wide ◽  
A Genome ◽  
Immunity Response ◽  
Species Specific

Microbe-associated molecular pattern (MAMP)-triggered immunity (MTI) is an important component of the plant innate immunity response to invading pathogens. Although several MTI responses can be measured in different plant species, their magnitude is probably plant species specific and even cultivar specific. In this study, a genome-wide transcriptome analysis of two soybean parental lines and two progeny lines treated for 30 min with the MAMPs flg22 and chitin was carried out. This analysis revealed a clear variation in gene expression, under both untreated and flg22+chitin-treated conditions. In addition, genes with potential additive and non-additive effects were identified in the two progeny lines, with several of these genes having a potential function in the control of innate immunity. The data presented herein represent the basis for further functional analysis that can lead to a better understanding of the soybean innate immunity response.

scholarly journals Genome-wide transcriptional profiling uncovers a similar oligodendrocyte-related transcriptional response to acute and chronic alcohol drinking in the amygdala

2021 ◽  
Author(s):  
Sharvari Narendra ◽  
Claudia Klengel ◽  
Bilal Hamzeh ◽  
Drasti Patel ◽  
Joy Otten ◽  
...  
Keyword(s):  
Gene Expression ◽  
Alcohol Drinking ◽  
Brain Area ◽  
Transcriptional Profiling ◽  
Expression Patterns ◽  
Transcriptional Response ◽  
Histone Deacetylation ◽  
Regulatory Pathways ◽  
Genome Wide ◽  
A Genome

AbstractAlcohol intake progressively increases after prolonged consumption of alcohol, but relatively few new therapeutics targeting development of alcohol use disorder (AUD) have been validated. Here, we conducted a genome-wide RNA-sequencing (RNA-seq) analysis in mice exposed to different modes (acute vs chronic) of ethanol drinking. We focused on transcriptional profiles in the amygdala including the central and basolateral subnuclei, a brain area previously implicated in alcohol drinking and seeking, demonstrating distinct gene expression patterns and canonical pathways induced by both acute and chronic intake. Surprisingly, both drinking modes triggered similar transcriptional changes, including up-regulation of ribosome-related/translational pathways and myelination pathways, and down-regulation of chromatin binding and histone modification. Notably, multiple genes that were significantly regulated in mouse amygdala with alcohol drinking, including Atp2b1, Slc4a7, Nfkb1, Nts, and Hdac2, among others had previously been associated with human AUD via GWAS or other genomic studies. In addition, analyses of hub genes and upstream regulatory pathways predicted that voluntary ethanol consumption affects epigenetic changes via histone deacetylation pathways, oligodendrocyte and myelin function, and oligodendrocyte-related transcriptional factor, Sox17.Overall, our results suggest that the transcriptional landscape in the central and basolateral subnuclei of the amygdala is sensitive to voluntary alcohol drinking. They provide a unique resource of gene expression data for future translational studies examining transcriptional mechanisms underlying the development of AUD due to alcohol consumption.

scholarly journals Phylogenomics for Chagas Disease Vectors of the Rhodnius Genus (Hemiptera, Triatominae): What We Learn From Mito-Nuclear Conflicts and Recommendations

2022 ◽  
Vol 9 ◽  
Author(s):  
Jonathan Filée ◽  
Marie Merle ◽  
Héloïse Bastide ◽  
Florence Mougel ◽  
Jean-Michel Bérenger ◽  
...  
Keyword(s):  
Molecular Data ◽  
Mitochondrial Genes ◽  
Valid Species ◽  
Close Relative ◽  
Protein Coding ◽  
Genome Wide ◽  
A Genome ◽  
Chagas Disease Vectors ◽  
Tree Topologies ◽  
Species Specific

We provide in this study a very large DNA dataset on Rhodnius species including 36 samples representing 16 valid species of the three Rhodnius groups, pictipes, prolixus and pallescens. Samples were sequenced at low-depth with whole-genome shotgun sequencing (Illumina technology). Using phylogenomics including 15 mitochondrial genes (13.3 kb), partial nuclear rDNA (5.2 kb) and 51 nuclear protein-coding genes (36.3 kb), we resolve sticking points in the Rhodnius phylogeny. At the species level, we confirmed the species-specific status of R. montenegrensis and R. marabaensis and we agree with the synonymy of R. taquarussuensis with R. neglectus. We also invite to revisit the species-specific status of R. milesi that is more likely R. nasutus. We proposed to define a robustus species complex that comprises the four close relative species: R. marabaensis, R. montenegrensis, R. prolixus and R. robustus. As Psammolestes tertius was included in the Rhodnius clade, we strongly recommend reclassifying this species as R. tertius. At the Rhodnius group level, molecular data consistently supports the clustering of the pictipes and pallescens groups, more related to each other than they are to the prolixus group. Moreover, comparing mitochondrial and nuclear tree topologies, our results demonstrated that various introgression events occurred in all the three Rhodnius groups, in laboratory strains but also in wild specimens. We demonstrated that introgressions occurred frequently in the prolixus group, involving the related species of the robustus complex but also the pairwise R. nasutus and R. neglectus. A genome wide analysis highlighted an introgression event in the pictipes group between R. stali and R. brethesi and suggested a complex gene flow between the three species of the pallescens group, R. colombiensis, R. pallescens and R. ecuadoriensis. The molecular data supports also a sylvatic distribution of R. prolixus in Brazil (Pará state) and the monophyly of R. robustus. As we detected extensive introgression events and selective pressure on mitochondrial genes, we strongly recommend performing separate mitochondrial and nuclear phylogenies and to take advantages of mito-nuclear conflicts in order to have a comprehensive evolutionary vision of this genus.

scholarly journals Regulatory divergence in wound-responsive gene expression in domesticated and wild tomato

2017 ◽  
Author(s):  
Ming-Jung Liu ◽  
Koichi Sugimoto ◽  
Sahra Uygun ◽  
Nicholas Panchy ◽  
Michael S. Campbell ◽  
...  
Keyword(s):  
Gene Expression ◽  
Stress Response ◽  
Transcriptional Response ◽  
Regulatory Elements ◽  
Expression Divergence ◽  
Solanum Pennellii ◽  
Responsive Gene ◽  
Mechanistic Basis ◽  
Species Specific ◽  
Regulatory Sites

ABSTRACTBackgroundThe evolution of cis- and trans-regulatory components of transcription is central to how stress response and tolerance differ across species. However, it remains largely unknown how divergence in TF binding specificity and cis-regulatory sites contribute to the divergence of stress-responsive gene expression between wild and domesticated species.ResultsUsing tomato as model, we analyzed the transcriptional profile of wound-responsive genes in wild Solanum pennellii and domesticated S. lycopersicum. We found that extensive expression divergence of wound-responsive genes is associated with speciation. To assess the degree of trans-regulatory divergence between these two species, 342 and 267 putative cis-regulatory elements (pCREs) in S. lycopersicum and S. pennellii, respectively, were identified that were predictive of wound-induced gene expression. We found that 35-66% of pCREs were conserved across species, suggesting that the remaining proportion (34-65%) of pCREs are species specific. This finding indicates a substantially higher degree of trans-regulatory divergence between these two plant species, which diverged ∼3-7 million years ago, compared to that observed in mouse and human, which diverged ∼100 million years ago. In addition, differences in pCRE sites were significantly associated with differences in wound-responsive gene expression between wild and domesticated tomato orthologs, suggesting the presence of substantial cis-regulatory divergence.ConclusionsOur study provides new insights into the mechanistic basis of how the transcriptional response to wounding is regulated and, importantly, the contribution of cis- and trans-regulatory components to variation in wound-responsive gene expression during species domestication.

scholarly journals Environmental temperatures shape thermal physiology as well as diversification and genome-wide substitution rates in lizards

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Joan Garcia-Porta ◽  
Iker Irisarri ◽  
Martin Kirchner ◽  
Ariel Rodríguez ◽  
Sebastian Kirchhof ◽  
...  
Keyword(s):  
Climatic Conditions ◽  
Evaporative Water ◽  
Substitution Rates ◽  
Preferred Temperature ◽  
Genome Wide ◽  
A Genome ◽  
Physiological Adaptations ◽  
Preferred Temperatures ◽  
Maximum Temperatures ◽  
Species Specific

Abstract Climatic conditions changing over time and space shape the evolution of organisms at multiple levels, including temperate lizards in the family Lacertidae. Here we reconstruct a dated phylogenetic tree of 262 lacertid species based on a supermatrix relying on novel phylogenomic datasets and fossil calibrations. Diversification of lacertids was accompanied by an increasing disparity among occupied bioclimatic niches, especially in the last 10 Ma, during a period of progressive global cooling. Temperate species also underwent a genome-wide slowdown in molecular substitution rates compared to tropical and desert-adapted lacertids. Evaporative water loss and preferred temperature are correlated with bioclimatic parameters, indicating physiological adaptations to climate. Tropical, but also some populations of cool-adapted species experience maximum temperatures close to their preferred temperatures. We hypothesize these species-specific physiological preferences may constitute a handicap to prevail under rapid global warming, and contribute to explaining local lizard extinctions in cool and humid climates.

Growth on mannitol-rich media elicits a genome-wide transcriptional response in Burkholderia multivorans that impacts on multiple virulence traits in an exopolysaccharide-independent manner

Microbiology ◽  
2014 ◽  
Vol 160 (1) ◽  
pp. 187-197 ◽  
Author(s):  
Carmen C. Denman ◽  
Matthew T. Robinson ◽  
Andrea M. Sass ◽  
Eshwar Mahenthiralingam ◽  
Alan R. Brown
Keyword(s):  
Burkholderia Cepacia ◽  
Stress Proteins ◽  
Galleria Mellonella ◽  
Transcriptional Response ◽  
Gene Clusters ◽  
Infection Model ◽  
Burkholderia Multivorans ◽  
Genome Wide ◽  
Rich Media ◽  
A Genome

In common with other members of the Burkholderia cepacia complex (BCC), Burkholderia multivorans is capable of producing exopolysaccharide (EPS) when grown on certain mannitol-rich media. The significance of the resulting mucoid phenotype and the genome-wide response to mannitol has never been characterized despite its clinical relevance following the approval of a dried-powder preparation of mannitol as an inhaled osmolyte therapy for cystic fibrosis (CF) patients. In the present study we defined the transcriptional response of B. multivorans ATCC 17616, a model genome-sequenced strain of environmental origin, to growth on mannitol-rich yeast extract media (MYEM). EPS-dependent and -independent impact of MYEM on virulence-associated traits was assessed in both strain ATCC 17616 and the CF isolate B. multivorans C1576. Our studies revealed a significant transcriptional response to MYEM encompassing approximately 23 % of predicted genes within the genome. Strikingly, this transcriptional response identified that EPS induction occurs in ATCC 17616 without the upregulation of the bce-I and bce-II EPS gene clusters, despite their pivotal role in EPS biosynthesis. Of approximately 20 differentially expressed putative virulence factors, 16 exhibited upregulation including flagella, ornibactin, oxidative stress proteins and phospholipases. MYEM-grown B. multivorans also exhibited enhanced motility, biofilm formation and epithelial cell invasion. In contrast to these potential virulence enhancements, MYEM-grown B. multivorans C1576 showed attenuated virulence in the Galleria mellonella infection model. All of the observed phenotypic responses occurred independently of EPS production, highlighting the profound impact that mannitol-based growth has on the physiology and virulence of B. multivorans.

scholarly journals Chromatin reprogramming in breast cancer

2018 ◽  
Vol 25 (7) ◽  
pp. R385-R404 ◽  
Author(s):  
Erin E Swinstead ◽  
Ville Paakinaho ◽  
Gordon L Hager
Keyword(s):  
Breast Cancer ◽  
Steroid Receptors ◽  
Transcriptional Response ◽  
Population Based ◽  
Cancer Proliferation ◽  
Enhancer Activity ◽  
Chromatin Dynamics ◽  
Genome Wide ◽  
A Genome ◽  
Chromatin Reprogramming

Reprogramming of the chromatin landscape is a critical component to the transcriptional response in breast cancer. Effects of sex hormones such as estrogens and progesterone have been well described to have a critical impact on breast cancer proliferation. However, the complex network of the chromatin landscape, enhancer regions and mode of function of steroid receptors (SRs) and other transcription factors (TFs), is an intricate web of signaling and functional processes that is still largely misunderstood at the mechanistic level. In this review, we describe what is currently known about the dynamic interplay between TFs with chromatin and the reprogramming of enhancer elements. Emphasis has been placed on characterizing the different modes of action of TFs in regulating enhancer activity, specifically, how different SRs target enhancer regions to reprogram chromatin in breast cancer cells. In addition, we discuss current techniques employed to study enhancer function at a genome-wide level. Further, we have noted recent advances in live cell imaging technology. These single-cell approaches enable the coupling of population-based assays with real-time studies to address many unsolved questions about SRs and chromatin dynamics in breast cancer.

scholarly journals Genome accessibility dynamics in response to phosphate limitation is controlled by the PHR1 family of transcription factors in Arabidopsis

2021 ◽  
Vol 118 (33) ◽  
pp. e2107558118
Author(s):  
Alfonso Carlos Barragán-Rosillo ◽  
Carlos Alberto Peralta-Alvarez ◽  
Jonathan Odilón Ojeda-Rivera ◽  
Rodrigo G. Arzate-Mejía ◽  
Félix Recillas-Targa ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Transcriptional Activation ◽  
Transcriptional Response ◽  
Phosphate Starvation ◽  
Chromatin Accessibility ◽  
Phosphate Limitation ◽  
Root Cells ◽  
Genome Wide ◽  
A Genome ◽  
Pi Starvation

As phosphorus is one of the most limiting nutrients in many natural and agricultural ecosystems, plants have evolved strategies that cope with its scarcity. Genetic approaches have facilitated the identification of several molecular elements that regulate the phosphate (Pi) starvation response (PSR) of plants, including the master regulator of the transcriptional response to phosphate starvation PHOSPHATE STARVATION RESPONSE1 (PHR1). However, the chromatin modifications underlying the plant transcriptional response to phosphate scarcity remain largely unknown. Here, we present a detailed analysis of changes in chromatin accessibility during phosphate starvation in Arabidopsis thaliana root cells. Root cells undergo a genome-wide remodeling of chromatin accessibility in response to Pi starvation that is often associated with changes in the transcription of neighboring genes. Analysis of chromatin accessibility in the phr1 phl2 double mutant revealed that the transcription factors PHR1 and PHL2 play a key role in remodeling chromatin accessibility in response to Pi limitation. We also discovered that PHR1 and PHL2 play an important role in determining chromatin accessibility and the associated transcription of many genes under optimal Pi conditions, including genes involved in the PSR. We propose that a set of transcription factors directly activated by PHR1 in Pi-starved root cells trigger a second wave of epigenetic changes required for the transcriptional activation of the complete set of low-Pi–responsive genes.

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