Global Gene Expression of Listeria monocytogenes to Salt Stress

2012 ◽  
Vol 75 (5) ◽  
pp. 906-912 ◽  
Author(s):  
DONGRYEOUL BAE ◽  
CONNIE LIU ◽  
TING ZHANG ◽  
MARCUS JONES ◽  
SCOTT N. PETERSON ◽  
...  
Keyword(s):  
Gene Expression ◽  
Salt Stress ◽  
Listeria Monocytogenes ◽  
Cell Growth ◽  
Expression Profiles ◽  
Brain Heart Infusion ◽  
Global Gene Expression ◽  
Phosphotransferase System ◽  
Transcript Levels ◽  
Qrt Pcr

Outbreaks of listeriosis caused by the ingestion of Listeria-contaminated ready-to-eat foods have been reported worldwide. Many ready-to-eat foods, such as deli meat products, contain high amounts of salt, which can disrupt the maintenance of osmotic balance within bacterial cells. To understand how Listeria monocytogenes adapts to salt stress, we examined the growth and global gene expression profiles of L. monocytogenes strain F2365 under salt stress using oligonucleotide probe-based DNA array and quantitative real-time PCR (qRT-PCR) analyses. The growth of L. monocytogenes in brain heart infusion (BHI) medium with various concentrations of NaCl (2.5, 5, and 10%) was significantly inhibited (P < 0.01) when compared with growth in BHI with no NaCl supplementation. Microarray data indicated that growth in BHI medium with 1.2% NaCl upregulated 4 genes and down-regulated 24 genes in L. monocytogenes, which was confirmed by qRT-PCR. The transcript levels of genes involved in the uptake of glycine betaine/l-proline were increased, whereas genes associated with a putative phosphoenolpyruvate-dependent sugar phosphotransferase system (PTS), metabolic enzymes, and virulence factor were down-regulated. Specifically, the expression levels of PTS transport genes were shown to be dependent on NaCl concentration. To further examine whether the down-regulation of PTS genes is related to decreased cell growth, the transcript levels of genes encoding components of enzyme II, involved in the uptake of various sugars used as the primary carbon source in bacteria, were also measured using qRT-PCR. Our results suggest that the decreased transcript levels of PTS genes may be caused by salt stress or reduced cell growth through salt stress. Here, we report global transcriptional profiles of L. monocytogenes in response to salt stress, contributing to an improved understanding of osmotolerance in this bacterium.

Global analysis of gene expression in an rpoN mutant of Listeria monocytogenes

Microbiology ◽  
2004 ◽  
Vol 150 (5) ◽  
pp. 1581-1590 ◽  
Author(s):  
Safia Arous ◽  
Carmen Buchrieser ◽  
Patrice Folio ◽  
Philippe Glaser ◽  
Abdelkader Namane ◽  
...  
Keyword(s):  
Gene Expression ◽  
Listeria Monocytogenes ◽  
Carbohydrate Metabolism ◽  
Global Analysis ◽  
Global Gene Expression ◽  
Mutant Gene ◽  
Wild Type ◽  
Phosphotransferase System ◽  
Two Dimensional Gel Electrophoresis ◽  
Catabolite Regulation

The role of the alternative σ 54 factor, encoded by the rpoN gene, was investigated in Listeria monocytogenes by comparing the global gene expression of the wild-type EGDe strain and an rpoN mutant. Gene expression, using whole-genome macroarrays, and protein content, using two-dimensional gel electrophoresis, were analysed. Seventy-seven genes and nine proteins, whose expression was modulated in the rpoN mutant as compared to the wild-type strain, were identified. Most of the modifications were related to carbohydrate metabolism and in particular to pyruvate metabolism. However, under the conditions studied, only the mptACD operon was shown to be directly controlled by σ 54. Therefore, the remaining modifications seem to be due to indirect effects. In parallel, an in silico analysis suggests that σ 54 may directly control the expression of four different phosphotransferase system (PTS) operons, including mptACD. PTS activity is known to have a direct effect on the pyruvate pool and on catabolite regulation. These results suggest that σ 54 is mainly involved in the control of carbohydrate metabolism in L. monocytogenes via direct regulation of PTS activity, alteration of the pyruvate pool and modulation of carbon catabolite regulation.

scholarly journals Identification of Listeria monocytogenes Genes Contributing to Intracellular Replication by Expression Profiling and Mutant Screening

2006 ◽  
Vol 188 (2) ◽  
pp. 556-568 ◽  
Author(s):  
Biju Joseph ◽  
Karin Przybilla ◽  
Claudia Stühler ◽  
Kristina Schauer ◽  
Jörg Slaghuis ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Stress Proteins ◽  
Carbon Sources ◽  
Brain Heart Infusion ◽  
Nitrogen Sources ◽  
Pentose Phosphate ◽  
Intracellular Growth ◽  
Cell Infection ◽  
Phosphotransferase System ◽  
Isoleucine Leucine

ABSTRACT A successful transition of Listeria monocytogenes from the extracellular to the intracellular environment requires a precise adaptation response to conditions encountered in the host milieu. Although many key steps in the intracellular lifestyle of this gram-positive pathogen are well characterized, our knowledge about the factors required for cytosolic proliferation is still rather limited. We used DNA microarray and real-time reverse transcriptase PCR analyses to investigate the transcriptional profile of intracellular L. monocytogenes following epithelial cell infection. Approximately 19% of the genes were differentially expressed by at least 1.6-fold relative to their level of transcription when grown in brain heart infusion medium, including genes encoding transporter proteins essential for the uptake of carbon and nitrogen sources, factors involved in anabolic pathways, stress proteins, transcriptional regulators, and proteins of unknown function. To validate the biological relevance of the intracellular gene expression profile, a random mutant library of L. monocytogenes was constructed by insertion-duplication mutagenesis and screened for intracellular-growth-deficient strains. By interfacing the results of both approaches, we provide evidence that L. monocytogenes can use alternative carbon sources like phosphorylated glucose and glycerol and nitrogen sources like ethanolamine during replication in epithelial cells and that the pentose phosphate cycle, but not glycolysis, is the predominant pathway of sugar metabolism in the host environment. Additionally, we show that the synthesis of arginine, isoleucine, leucine, and valine, as well as a species-specific phosphoenolpyruvate-dependent phosphotransferase system, play a major role in the intracellular growth of L. monocytogenes.

scholarly journals 1446. Dynamics of Enterococcus faecalis Cardiolipin Synthase Gene Expression Reveal Compensatory Roles in Daptomycin Resistance

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S726-S726
Author(s):  
April Nguyen ◽  
Vinathi Polamraju ◽  
Truc T Tran ◽  
Diana Panesso-Botero ◽  
Ayesha Khan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Research Study ◽  
Expression Profiles ◽  
Scientific Research ◽  
Bacterial Survival ◽  
Acridine Orange Staining ◽  
Qrt Pcr ◽  
Study Investigator ◽  
Study Gene Expression ◽  
Cardiolipin Synthase

Abstract Background Daptomycin (DAP) is a lipopeptide antibiotic targeting membrane anionic phospholipids (APLs) at the division septum, and resistance (DAP-R) has been linked to mutations in genes encoding i) the LiaFSR stress response system or its effector LiaX, and ii) cardiolipin synthase (Cls). Activation of the E. faecalis (Efs) LiaFSR response is associated with DAP-R and redistribution of APL microdomains away from the septum, and cardiolipin is predicted to be a major component of these APL microdomains. Efs harbors two putative cls genes, cls1 and cls2. While changes in Cls1 have been implicated in DAP-R, the exact roles of each enzyme in resistance are unknown. We aim to characterize the contributions of Cls1 and Cls2 in the development of DAP-R. Methods cls1 and cls2 were deleted individually and in tandem from DAP-S Efs OG117 and DAP-R Efs OG117∆liaX (a DAP-R derivative strain with an activated LiaFSR response). Mutants were characterized by DAP minimum inhibitory concentration (MIC) using E-test on Mueller-Hinton II agar and localization of APL microdomains with 10-N-nonyl-acridine orange staining. Quantitative PCR (qRT-PCR) was used to study gene expression profiles of cls1 and cls2 in Efs OG117∆liaX relative to Efs OG117 across the cell growth cycle. Results qRT-PCR revealed differential expression profiles of cls1 and cls2 associated with DAP-R. cls1 was highly upregulated in stationary phase concurrent with a decrease in cls2 expression. However, independent deletion of cls1 or cls2 in the DAP-R background resulted in no significant changes in DAP MICs or localization of APL microdomains (remaining non-septal). Further studies revealed that cls2 expression is upregulated upon deletion of cls1 in both the DAP-S and DAP-R background, suggesting a potential compensatory role for Cls2. Double deletion of both cls genes in the DAP-R strain decreased DAP MIC and restored the septal localization of APL microdomains. Conclusion Cls1 is the major and predominant enzyme involved in cell membrane adaptation associated with the development of DAP-R in E. faecalis. However, we describe a novel compensatory and overlapping role for cardiolipin synthases to ensure bacterial survival upon attack from antimicrobial peptides and related antibiotics. Disclosures Cesar A. Arias, MD, MSc, PhD, FIDSA, Entasis Therapeutics (Scientific Research Study Investigator)MeMed (Scientific Research Study Investigator)Merck (Grant/Research Support)

scholarly journals Granulosa cells from human primordial and primary follicles show differential global gene expression profiles

2018 ◽  
Vol 33 (4) ◽  
pp. 666-679 ◽  
Author(s):  
E H Ernst ◽  
S Franks ◽  
K Hardy ◽  
P Villesen ◽  
K Lykke-Hartmann
Keyword(s):  
Gene Expression ◽  
Granulosa Cells ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Global Gene Expression

scholarly journals Dynamical consequences of regional heterogeneity in the brain’s transcriptional landscape

2020 ◽  
Author(s):  
Gustavo Deco ◽  
Kevin Aquino ◽  
Aurina Arnatkevičiūtė ◽  
Stuart Oldham ◽  
Kristina Sabaroedin ◽  
...  
Keyword(s):  
Gene Expression ◽  
Large Scale ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Global Gene Expression ◽  
Brain Regions ◽  
Biophysical Model ◽  
Neuronal Dynamics ◽  
Regional Heterogeneity ◽  
Magnetic Resonance Imaging Mri

AbstractBrain regions vary in their molecular and cellular composition, but how this heterogeneity shapes neuronal dynamics is unclear. Here, we investigate the dynamical consequences of regional heterogeneity using a biophysical model of whole-brain functional magnetic resonance imaging (MRI) dynamics in humans. We show that models in which transcriptional variations in excitatory and inhibitory receptor (E:I) gene expression constrain regional heterogeneity more accurately reproduce the spatiotemporal structure of empirical functional connectivity estimates than do models constrained by global gene expression profiles and MRI-derived estimates of myeloarchitecture. We further show that regional heterogeneity is essential for yielding both ignition-like dynamics, which are thought to support conscious processing, and a wide variance of regional activity timescales, which supports a broad dynamical range. We thus identify a key role for E:I heterogeneity in generating complex neuronal dynamics and demonstrate the viability of using transcriptional data to constrain models of large-scale brain function.

scholarly journals Comparative gene expression profiling of mouse ovaries upon stimulation with natural equine chorionic gonadotropin (N-eCG) and tethered recombinant-eCG (R-eCG)

2020 ◽  
Author(s):  
Kwan-Sik Min ◽  
Jong-Ju Park ◽  
So-Yun Lee ◽  
Munkhzaya Byambaragchaa ◽  
Myung-Hwa Kang
Keyword(s):  
Gene Expression ◽  
Chorionic Gonadotropin ◽  
Expression Profiles ◽  
Expression System ◽  
Laboratory Animals ◽  
Metabolic Clearance ◽  
Qrt Pcr ◽  
Significant Difference ◽  
Equine Chorionic Gonadotropin

Abstract Background: Equine chorionic gonadotropin (eCG) induces super-ovulation in laboratory animals. Notwithstanding its extensive usage, limited information is available regarding the differences between the in vivo effects of natural eCG (N-eCG) and recombinant eCG (R-eCG). This study aimed to investigate the gene expression profiles of mouse ovaries upon stimulation with N-eCG and R-eCG produced from CHO-suspension (CHO-S) cells. R-eCG gene was constructed and transfected into CHO-S cells and quantified. Subsequently, we determined the metabolic clearance rate (MCR) of N-eCG and R-eCG up to 24 h after intravenous administration through the mice tail vein and identified differentially expressed genes in both ovarian tissues, via quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC).Results: R-eCG was markedly expressed initially after transfection and maintained until recovery on day 9. Glycan chains were substantially modified in R-eCG protein produced from CHO-S cells and eliminated through PNGase F treatment. The MCR was higher for R-eCG than for N-eCG, and no significant difference was observed after 60 min. Notwithstanding their low concentrations, R-eCG and N-eCG were detected in the blood at 24h post-injection. Microarray analysis of ovarian tissue revealed that 20 of 12,816 genes assessed therein were significantly up-regulated and 43 genes were down-regulated by >2-fold in the group that received R-eCG (63 [0.49%] differentially regulated genes in total). The microarray results were concurrent with and hence validated by those of RT-PCR, qRT-PCR, and IHC analyses.Conclusions: The present results indicate that R-eCG can be adequately produced through a cell-based expression system through post-translational modification of eCG and can induce ovulation in vivo. These results provide novel insights into the molecular mechanisms underlying the up- or down-regulation of specific ovarian genes and the production of R-eCG with enhanced biological activity in vivo.

scholarly journals Identification and validation of miRNA reference genes in poplar under pathogen stress

2021 ◽  
Author(s):  
Lichun Zhang ◽  
Xiaoqian Yang ◽  
Yiyi Yin ◽  
Jinxing Wang ◽  
Yanwei Wang
Keyword(s):  
Gene Expression ◽  
Reference Gene ◽  
Small Rna ◽  
Reference Genes ◽  
Expression Profiles ◽  
Small Rna Sequencing ◽  
Rna Seq ◽  
Internal Standards ◽  
Qrt Pcr ◽  
Canker Pathogen

Abstract Quantitative real time polymerase chain reaction (qRT-PCR) is a common method to analyze gene expression. Due to differences in RNA quantity, quality, and reverse transcription efficiency between qRT-PCR samples, reference genes are used as internal standards to normalize gene expression. However, few universal genes especially miRNAs have been identified as reference so far. Therefore, it is essential to identify reference genes that can be used across various experimental conditions, stress treatments, or tissues. In this study, 14 microRNAs (miRNAs) and 5.8S rRNA were assessed for expression stability in poplar trees infected with canker pathogen. Using three reference gene analysis programs, we found that miR156g and miR156a exhibited stable expression throughout the infection process. miR156g and miR156a were then tested as internal standards to measure the expression of miR1447 and miR171c, and the results were compared to small RNA sequencing (RNA-seq) data. We found that when miR156a was used as the reference gene, the expression of miR1447 and miR171c were consistent with the small RNA-seq expression profiles. Therefore, miR156a was the most stable miRNAs examined in this study, and could be used as a reference gene in poplar under canker pathogen stress, which should enable comprehensive comparisons of miRNAs expression and avoid the bias caused by different lenth between detected miRNAs and traditional referece genes. The present study has expanded the miRNA reference genes available for gene expression studies in trees under biotic stress.

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