scholarly journals Cyanobacterial viruses exhibit diurnal rhythms during infection

2019 ◽  
Vol 116 (28) ◽  
pp. 14077-14082 ◽  
Author(s):  
Riyue Liu ◽  
Yaxin Liu ◽  
Yue Chen ◽  
Yuanchao Zhan ◽  
Qinglu Zeng
Keyword(s):  
Gene Expression ◽  
Light Exposure ◽  
Population Level ◽  
Transcript Abundance ◽  
Mechanistic Explanation ◽  
Underlying Mechanism ◽  
Laboratory Culture ◽  
Culture Conditions ◽  
Host Cells ◽  
Diurnal Rhythms

As an adaptation to the daily light–dark (diel) cycle, cyanobacteria exhibit diurnal rhythms of gene expression and cell cycle. The light–dark cycle also affects the life cycle of viruses (cyanophages) that infect the unicellular picocyanobacteriaProchlorococcusandSynechococcus, which are the major primary producers in the oceans. For example, the adsorption of some cyanophages to the host cells depends on light, and the burst sizes of cyanophages are positively correlated to the length of light exposure during infection. Recent metatranscriptomic studies revealed transcriptional rhythms of field cyanophage populations. However, the underlying mechanism remains to be determined, as cyanophage laboratory cultures have not been shown to exhibit diurnal transcriptional rhythms. Here, we studied variation in infection patterns and gene expression ofProchlorococcusphages in laboratory culture conditions as a function of light. We found three distinct diel-dependent life history traits in dark conditions (diel traits): no adsorption (cyanophage P-HM2), adsorption but no replication (cyanophage P-SSM2), and replication (cyanophage P-SSP7). Under light–dark cycles, each cyanophage exhibited rhythmic transcript abundance, and cyanophages P-HM2 and P-SSM2 also exhibited rhythmic adsorption patterns. Finally, we show evidence to link the diurnal transcriptional rhythm of cyanophages to the photosynthetic activity of the host, thus providing a mechanistic explanation for the field observations of cyanophage transcriptional rhythms. Our study identifies that cultured viruses can exhibit diurnal rhythms during infection, which might impact cyanophage population-level dynamics in the oceans.

279 DIFFERENCES IN TRANSCRIPT ABUNDANCE BETWEEN MALE AND FEMALE BOVINE BLASTOCYSTS PRODUCED IN VITRO USING SEXED SEMEN

2007 ◽  
Vol 19 (1) ◽  
pp. 255
Author(s):  
D. Rizos ◽  
P. Lonergan ◽  
D. Rath ◽  
J. De la Fuente ◽  
M. Wade ◽  
...  
Keyword(s):  
Gene Expression ◽  
Relative Abundance ◽  
Dna Methyltransferase ◽  
High Sensitivity ◽  
Transcript Abundance ◽  
Culture Conditions ◽  
Interferon Tau ◽  
Fluid Medium ◽  
Male And Female

There is considerable evidence in the literature indicating that, depending on the culture environment, male pre-implantation embryos develop faster than females, with, for example, a higher proportion of early developing blastocysts being male. The aim of this study was to examine gender-related differences in gene expression in bovine blastocysts produced in vitro following IVF with sex-sorted, frozen–thawed semen. For blastocyst production, immature cumulus–oocyte complexes (COCs) recovered from the ovaries of slaughtered heifers were matured in vitro for 24 h. Matured COCs were randomly split into 2 groups and inseminated with frozen–thawed sperm sorted flow cytometrically for gender. Presumptive zygotes were cultured for 7 days in synthetic oviduct fluid medium. In a preliminary experiment, blastocysts (XX: n = 61; XY: n = 47) were recovered on Day 8 post-insemination and individually snap frozen in liquid nitrogen for verification of the sorting procedure. Sexing was performed with PCR using both male-specific (BRY4.a) and bovine satellite primers. The proportion of female and male blastocysts obtained with X- and Y-chromosome-bearing sperm was 87.2 and 80.3%, respectively. In a subsequent 5 replicates, Day 8 blastocysts were snap frozen in groups of 10 for analysis of mRNA relative abundance. These developmentally important genes were selected based on microarray analysis because they showed a high sensitivity to suboptimal in vitro culture conditions (data not shown). There was no difference in the relative abundance of desmocollin II (DcII), Na/K-ATPase alpha1 subunit (Na/K), ubiquitin-activating enzyme E2 (Ube2), fibroblast growth factor 4 (FGF4), and DNA methyltransferase 1 (Dnmt1) between male and female blastocysts. X-inactive specific transcript (Xist), interferon-tau (IFN), and a Sry-related HMG box transcriptoinal factor (Sox17) were significantly up-regulated in female blastocysts, whereas DNA methyltransferase 3a (Dnmt3a), DNA methyltransferase 3b (Dnmt3b), sarcosine oxidase (Sox), and the transcription factor Oct-4 were significantly up-regulated in males. In conclusion, differences in gene expression between male and female embryos exist and may be related to the well-described differences in the kinetics of development.

scholarly journals Investigating the expression of F10 and G11 xylanases in Aspergillus niger A09 with qPCR

2016 ◽  
Vol 62 (9) ◽  
pp. 744-752
Author(s):  
Shixiu Cui ◽  
Tianwen Wang ◽  
Hong Hu ◽  
Liangwei Liu ◽  
Andong Song ◽  
...  
Keyword(s):  
Gene Expression ◽  
Aspergillus Niger ◽  
Culture Media ◽  
Xylanase Activity ◽  
Nitrogen Sources ◽  
Transcript Abundance ◽  
Culture Conditions ◽  
Clear Understanding ◽  
Carbon And Nitrogen Sources ◽  
Carbon And Nitrogen

There exist significant differences between the 2 main types of xylanases, family F10 and G11. A clear understanding of the expression pattern of microbial F10 and G11 under different culture conditions would facilitate better production and industrial application of xylanase. In this study, the fungal xylanase producer Aspergillus niger A09 was systematically investigated in terms of induced expression of xylanase F10 and G11. Results showed that carbon and nitrogen sources could influence xylanase F10 and G11 transcript abundance, with G11 more susceptible to changes in culture media composition. The most favorable carbon and nitrogen sources for high G11 and low F10 production by A. niger A09 were xylan (2%) and (NH4)2C2O4 (0.3%), respectively. Following cultivation at 33 °C for 60 h, the highest xylanase activity (1132 IU per gram of wet mycelia) was observed. On the basis of differential gene expression of F10 and G11, as well as their different properties, we deduced that the F10 protein initially targeted xylan and hydrolyzed it into fragments including xylose, after which xylose acted as the inducer of F10 and G11 gene expression. These speculations also accounted for our failure to identify conditions favoring the high production of F10 but a low production of G11.

scholarly journals Gene network expression of whole blood leukocytes in dairy cows with different milk yield at dry-off

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260745
Author(s):  
Luca Cattaneo ◽  
Matteo Mezzetti ◽  
Vincenzo Lopreiato ◽  
Fiorenzo Piccioli-Cappelli ◽  
Erminio Trevisi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Inflammatory Response ◽  
Dairy Cows ◽  
Milk Yield ◽  
Whole Blood ◽  
Mixed Model ◽  
Transcript Abundance ◽  
Underlying Mechanism ◽  
Blood Leukocytes ◽  
Blood Leukocyte

Dairy cows at dry-off undergo several management and physiological changes, resulting in alterations in plasma biomarkers of inflammation, oxidative stress, and immune system. High milk yield at the end of lactation exacerbates these responses. The underlying mechanism of these changes has yet to be elucidated. We hypothesized altered leukocyte gene expression after dry-off and different responses in cows with different milk yield. Thirteen Holstein dairy cows were sampled at the turn of dry-off to investigated whole blood leukocyte gene expression and were grouped according to the average milk yield during the last week of lactation: low (< 15 kg/d) and high milk yield (> 15 kg/d). Blood samples were collected in PAXgene tubes (Preanalytix, Hombrechtikon, Switzerland) at -7, 7, and 34 days from dry-off (DFD) to measure mRNA abundance of 37 genes. Normalized gene abundance data were subjected to MIXED model ANOVA (SAS Institute Inc., Cary, NC). Compared with -7 DFD, at 7 DFD RNA abundance of lipoxygenase genes (ALOX5, ALOX15) and myeloperoxidase (MPO) increased, and that of the antioxidant gene (SOD2) decreased. Meanwhile, genes related to recognition and immune mediation (CD16, MYD88, TLR2), migration and cell adhesion (CX3CR1, ITGAL, ITGB2, TLN1), and the antimicrobial gene MMP9 were downregulated at 7 or 34 DFD, whereas the antimicrobial IDO1 gene was upregulated. Compared with low-producing cows, cows with high milk yield at dry-off cows had upregulated expression of the pro-inflammatory cytokines IL8 and IL18 and a greater reduction in transcript abundance of the toll-like receptor (TLR) recognition-related gene TLR2. Overall, the dry-off confirmed to be a phase of intense changes, triggering an inflammatory response and somewhat suppressing leukocyte immune function. In cows with high milk yield during the week before dry-off, the inflammatory response was exacerbated.

scholarly journals Regulation of Expression of the Borrelia burgdorferi β3-Chain Integrin Ligand, P66, in Ticks and in Culture

2003 ◽  
Vol 71 (2) ◽  
pp. 1001-1007 ◽  
Author(s):  
Carla Cugini ◽  
Melisa Medrano ◽  
Tom G. Schwan ◽  
Jenifer Coburn
Keyword(s):  
Gene Expression ◽  
Borrelia Burgdorferi ◽  
In Vitro Culture ◽  
Laboratory Culture ◽  
Culture Conditions ◽  
Infection Cycle ◽  
Regulation Of Expression ◽  
Integrin Ligand

ABSTRACT Borrelia burgdorferi is maintained in an infection cycle between mammalian and arthropod hosts. Appropriate gene expression by B. burgdorferi at different stages of this cycle is probably essential for transmission and establishment of infection. The B. burgdorferi β3 integrin ligand P66 is expressed by the bacteria in mammals, laboratory culture, and engorged but not unfed ticks. No in vitro culture conditions in which P66 expression reflected that in the unfed tick were found, suggesting that there are aspects of B. burgdorferi-tick interaction that remain unexplored.

Establishing Standard Protocols for Bacterial Culture in Biological Research in Canisters (BRIC) Hardware

2020 ◽  
Vol 4 (2) ◽  
pp. 58-69 ◽  
Author(s):  
Patricia Fajardo-Cavazos ◽  
Wayne L. Nicholson
Keyword(s):  
Gene Expression ◽  
Bacterial Culture ◽  
Culture Conditions ◽  
Media Culture ◽  
Ground Control ◽  
Biological Research ◽  
Confounding Factors ◽  
Cross Experiment ◽  
Spaceflight Experiments ◽  
Control Samples

AbstractThe NASA GeneLab Data System (GLDS) was recently developed to facilitate cross-experiment comparisons in order to understand the response of microorganisms to the human spaceflight environment. However, prior spaceflight experiments have been conducted using a wide variety of different hardware, media, culture conditions, and procedures. Such confounding factors could potentially mask true differences in gene expression between spaceflight and ground control samples. In an attempt to mitigate such confounding factors, we describe here the development of a standardized set of hardware, media, and protocols for liquid cultivation of microbes in Biological Research in Canisters (BRIC) spaceflight hardware, using the model bacteria Bacillus subtilis strain 168 and Staphylococcus aureus strain UAMS-1 as examples.

Mechanical culture conditions effect gene expression

2001 ◽  
Author(s):  
J. Love ◽  
T. Hammond ◽  
P. Allen ◽  
L. Cubano ◽  
T. Baker ◽  
...  
Keyword(s):  
Gene Expression ◽  
Culture Conditions ◽  
Effect Gene

scholarly journals Time-resolved transcriptional profiling of Trichinella-infected murine myocytes helps to elucidate host–pathogen interactions in the muscle stage

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Xiaoxiang Hu ◽  
Xiaolei Liu ◽  
Chen Li ◽  
Yulu Zhang ◽  
Chengyao Li ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Biology ◽  
Trichinella Spiralis ◽  
Expression Patterns ◽  
Muscle Cells ◽  
Host Cells ◽  
Initial Reaction ◽  
Global Changes ◽  
Mammalian Skeletal Muscle ◽  
Time Resolved

Abstract Background Parasites of the genus Trichinella are the pathogenic agents of trichinellosis, which is a widespread and severe foodborne parasitic disease. Trichinella spiralis resides primarily in mammalian skeletal muscle cells. After invading the cells of the host organism, T. spiralis must elude or invalidate the host’s innate and adaptive immune responses to survive. It is necessary to characterize the pathogenesis of trichinellosis to help to prevent the occurrence and further progression of this disease. The aims of this study were to elucidate the mechanisms of nurse cell formation, pathogenesis and immune evasion of T. spiralis, to provide valuable information for further research investigating the basic cell biology of Trichinella-infected muscle cells and the interaction between T. spiralis and its host. Methods We performed transcriptome profiling by RNA sequencing to identify global changes at 1, 3, 7, 10 and 15 days post-infection (dpi) in gene expression in the diaphragm after the parasite entered and persisted within the murine myocytes; the mice were infected by intravenous injection of newborn larvae. Gene expression analysis was based on the alignment results. Differentially expressed genes (DEGs) were identified based on their expression levels in various samples, and functional annotation and enrichment analysis were performed. Results The most extensive and dynamic gene expression responses in host diaphragms were observed during early infection (1 dpi). The number of DEGs and genes annotated in the Kyoto Encyclopedia of Genes and Genomes and Gene Ontology databases decreased significantly in the infected mice compared to the uninfected mice at 3 and 7 dpi, suddenly increased sharply at 10 dpi, and then decreased to a lower level at 15 dpi, similar to that observed at 3 and 7 dpi. The massive initial reaction of the murine muscle cells to Trichinella infection steadied in the later stages of infection, with little additional changes detected for the remaining duration of the studied process. Although there were hundreds of DEGs at each time point, only 11 genes were consistently up- or downregulated at all 5 time points. Conclusions The gene expression patterns identified in this study can be employed to characterize the coordinated response of T. spiralis-infected myocytes in a time-resolved manner. This comprehensive dataset presents a distinct and sensitive picture of the interaction between host and parasite during intracellular infection, which can help to elucidate how pathogens evade host defenses and coordinate the biological functions of host cells to survive in the mammalian environment.

scholarly journals SARS-CoV-2 Entry: At the Crossroads of CD147 and ACE2

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1434
Author(s):  
Claudio Fenizia ◽  
Silvia Galbiati ◽  
Claudia Vanetti ◽  
Riccardo Vago ◽  
Mario Clerici ◽  
...  
Keyword(s):  
Underlying Mechanism ◽  
Membrane Receptors ◽  
Host Cells ◽  
Viral Agent ◽  
Blocking Antibody ◽  
Angiotensin Converting Enzyme 2 ◽  
Host Membrane ◽  
B Virus ◽  
Immunodeficiency Virus

In late 2019, the betacoronavirus SARS-CoV-2 was identified as the viral agent responsible for the coronavirus disease 2019 (COVID-19) pandemic. Coronaviruses Spike proteins are responsible for their ability to interact with host membrane receptors and different proteins have been identified as SARS-CoV-2 interactors, among which Angiotensin-converting enzyme 2 (ACE2), and Basigin2/EMMPRIN/CD147 (CD147). CD147 plays an important role in human immunodeficiency virus type 1, hepatitis C virus, hepatitis B virus, Kaposi’s sarcoma-associated herpesvirus, and severe acute respiratory syndrome coronavirus infections. In particular, SARS-CoV recognizes the CD147 receptor expressed on the surface of host cells by its nucleocapsid protein binding to cyclophilin A (CyPA), a ligand for CD147. However, the involvement of CD147 in SARS-CoV-2 infection is still debated. Interference with both the function (blocking antibody) and the expression (knock down) of CD147 showed that this receptor partakes in SARS-CoV-2 infection and provided additional clues on the underlying mechanism: CD147 binding to CyPA does not play a role; CD147 regulates ACE2 levels and both receptors are affected by virus infection. Altogether, these findings suggest that CD147 is involved in SARS-CoV-2 tropism and represents a possible therapeutic target to challenge COVID-19.

scholarly journals “Limiting access to iron decreases infection of Atlantic salmon SHK-1 cells with bacterium Piscirickettsia salmonis”

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Rodrigo Díaz ◽  
José Troncoso ◽  
Eva Jakob ◽  
Stanko Skugor
Keyword(s):  
Gene Expression ◽  
Iron Deficiency ◽  
Atlantic Salmon ◽  
Bacterial Load ◽  
Host Cells ◽  
Immune Gene ◽  
Immune Signaling ◽  
Immune Effector ◽  
Infected Cells ◽  
Piscirickettsia Salmonis

Abstract Background Vertebrate hosts limit the availability of iron to microbial pathogens in order to nutritionally starve the invaders. The impact of iron deficiency induced by the iron chelator deferoxamine mesylate (DFO) was investigated in Atlantic salmon SHK-1 cells infected with the facultative intracellular bacterium Piscirickettsia salmonis. Results Effects of the DFO treatment and P. salmonis on SHK-1 cells were gaged by assessing cytopathic effects, bacterial load and activity, and gene expression profiles of eight immune biomarkers at 4- and 7-days post infection (dpi) in the control group, groups receiving single treatments (DFO or P. salmonis) and their combination. The chelator appears to be well-tolerated by host cells, while it had a negative impact on the number of bacterial cells and associated cytotoxicity. DFO alone had minor effects on gene expression of SHK-1 cells, including an early activation of IL-1β at 4 dpi. In contrast to few moderate changes induced by single treatments (either infection or chelator), most genes had highest upregulation in the infected groups receiving DFO. The mildest induction of hepcidin-1 (antimicrobial peptide precursor and regulator of iron homeostasis) was observed in cells exposed to DFO alone, followed by P. salmonis infected cells while the addition of DFO to infected cells further increased the mRNA abundance of this gene. Transcripts encoding TNF-α (immune signaling) and iNOS (immune effector) showed sustained increase at both time points in this group while cathelicidin-1 (immune effector) and IL-8 (immune signaling) were upregulated at 7 dpi. The stimulation of protective gene responses seen in infected cultures supplemented with DFO coincided with the reduction of bacterial load and activity (judged by the expression of P. salmonis 16S rRNA), and damage to cultured host cells. Conclusion The absence of immune gene activation under normal iron conditions suggests modulation of host responses by P. salmonis. The negative effect of iron deficiency on bacteria likely allowed host cells to respond in a more protective manner to the infection, further decreasing its progression. Presented findings encourage in vivo exploration of iron chelators as a promising strategy against piscirickettsiosis.

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