scholarly journals Gene Expression in Parthenogenic Maize Proembryos

Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 964
Author(s):  
Irina Volokhina ◽  
Yury Gusev ◽  
Yelizaveta Moiseeva ◽  
Olga Gutorova ◽  
Vladimir Fadeev ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
High Frequency ◽  
Maize Line ◽  
Triggering Mechanism ◽  
Maize Hybrids ◽  
Modern Maize ◽  
First Time

Angiosperm plants reproduce both sexually and asexually (by apomixis). In apomictic plants, the embryo and endosperm develop without fertilization. Modern maize seems to have a broken apomixis-triggering mechanism, which still works in Tripsacum and in Tripsacum–maize hybrids. For the first time, maize lines characterized by pronounced and inheritable high-frequency maternal parthenogenesis were generated 40 years ago, but there are no data on gene expression in parthenogenic maize proembryos. Here we examined for the first time gene expression in parthenogenic proembryos isolated from unpollinated embryo sacs (ESs) of a parthenogenic maize line (AT-4). The DNA-methylation genes (dmt103, dmt105) and the genes coding for the chromatin-modifying enzymes (chr106, hdt104, hon101) were expressed much higher in parthenogenic proembryos than in unpollinated ESs. The expression of the fertilization-independent endosperm (fie1) genes was found for the first time in parthenogenic proembryos and unpollinated ESs. In parthenogenic proembryos, the Zm_fie2 gene was expressed up to two times higher than it was expressed in unpollinated ESs.

scholarly journals Sleep deprivation and diet affect human GH gene expression in transgenic mice in vivo

2020 ◽  
Vol 9 (12) ◽  
pp. 1135-1147
Author(s):  
Jessica S Jarmasz ◽  
Yan Jin ◽  
Hana Vakili ◽  
Peter A Cattini
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Sleep Deprivation ◽  
Chow Diet ◽  
Negative Effects ◽  
Production Studies ◽  
First Time ◽  
Rna Levels

Human (h) growth hormone (GH) production studies are largely limited to effects on secretion. How pituitary hGH gene (hGH-N/GH1) expression is regulated is important in our understanding of the role hGH plays in physiology and disease. Here we assess for the first time the effect of sleep deprivation (SD) and high-fat diet (HFD) on hGH-N expression in vivo using partially humanized 171hGH/CS transgenic (TG) mice, and attempted to elucidate a role for DNA methylation. Activation of hGH-N expression requires interactions between promoter and upstream locus control region (LCR) sequences including pituitary-specific hypersensitive site (HS) I/II. Both SD and diet affect hGH secretion, but the effect of SD on hGH-N expression is unknown. Mice fed a HFD or regular chow diet for 3 days underwent SD (or no SD) for 6 h at Zeitgeber time (ZT) 3. Serum and pituitaries were assessed over 24 h at 6-h intervals beginning at ZT 14. SD and HFD caused significant changes in serum corticosterone and insulin, as well as hGH and circadian clock-related gene RNA levels. No clear association between DNA methylation and the negative effects of SD or diet on hGH RNA levels was observed. However, a correlation with increased methylation at a CpG (cytosine paired with a guanine) in a putative E-box within the hGH LCR HS II was suggested in situ. Methylation at this site also increased BMAL1/CLOCK-related nuclear protein binding in vitro. These observations support an effect of SD on hGH synthesis at the level of gene expression.

scholarly journals Occupational exposure to pesticides is associated with differential DNA methylation

2018 ◽  
Vol 75 (6) ◽  
pp. 427-435 ◽  
Author(s):  
Diana A van der Plaat ◽  
Kim de Jong ◽  
Maaike de Vries ◽  
Cleo C van Diemen ◽  
Ivana Nedeljković ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Occupational Exposure ◽  
Airway Obstruction ◽  
Pesticide Exposure ◽  
Airway Disease ◽  
Disease Pathogenesis ◽  
Genome Wide ◽  
Wide Range ◽  
First Time

ObjectivesOccupational pesticide exposure is associated with a wide range of diseases, including lung diseases, but it is largely unknown how pesticides influence airway disease pathogenesis. A potential mechanism might be through epigenetic mechanisms, like DNA methylation. Therefore, we assessed associations between occupational exposure to pesticides and genome-wide DNA methylation sites.Methods1561 subjects of LifeLines were included with either no (n=1392), low (n=108) or high (n=61) exposure to any type of pesticides (estimated based on current or last held job). Blood DNA methylation levels were measured using Illumina 450K arrays. Associations between pesticide exposure and 420 938 methylation sites (CpGs) were assessed using robust linear regression adjusted for appropriate confounders. In addition, we performed genome-wide stratified and interaction analyses by gender, smoking and airway obstruction status, and assessed associations between gene expression and methylation for genome-wide significant CpGs (n=2802).ResultsIn total for all analyses, high pesticide exposure was genome-wide significantly (false discovery rate P<0.05) associated with differential DNA methylation of 31 CpGs annotated to 29 genes. Twenty of these CpGs were found in subjects with airway obstruction. Several of the identified genes, for example, RYR1, ALLC, PTPRN2, LRRC3B, PAX2 and VTRNA2-1, are genes previously linked to either pesticide exposure or lung-related diseases. Seven out of 31 CpGs were associated with gene expression levels.ConclusionsWe show for the first time that occupational exposure to pesticides is genome-wide associated with differential DNA methylation. Further research should reveal whether this differential methylation plays a role in the airway disease pathogenesis induced by pesticides.

scholarly journals Prognostic Significance of Gene Expression and DNA Methylation Markers in Circulating Tumor Cells and Paired Plasma Derived Exosomes in Metastatic Castration Resistant Prostate Cancer

Cancers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 780
Author(s):  
Martha Zavridou ◽  
Areti Strati ◽  
Evangelos Bournakis ◽  
Stavroula Smilkou ◽  
Victoria Tserpeli ◽  
...  
Keyword(s):  
Gene Expression ◽  
Prostate Cancer ◽  
Dna Methylation ◽  
Tumor Cells ◽  
Liquid Biopsy ◽  
Prognostic Significance ◽  
Comparison Study ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant ◽  
First Time

Liquid biopsy, based on the analysis of circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA), provides non-invasive real-time monitoring of tumor evolution and therapeutic efficacy. We performed for the first time a direct comparison study on gene expression and DNA methylation markers in CTCs and paired plasma-derived exosomes and evaluated their prognostic significance in metastatic castration resistant prostate cancer. This prospective liquid biopsy (LB) study was based on a group of 62 metastatic castration resistant prostate cancer (mCRPC) patients and 10 healthy donors (HD) as controls. Identical blood draws were used to: (a) enumerate CTC and tumor-derived extracellular vesicles (tdEVs) using CellSearch (CS) and (b) analyze CTCs and paired plasma-derived exosomes at the gene expression and DNA methylation level. CTCs were enumerated using CellSearch in 57/62 patients, with values ranging from 5 to 854 cells/7.5 mL PB. Our results revealed for the first time a significantly higher positivity of gene expression markers (CK-8, CK-18, TWIST1, PSMA, AR-FL, AR-V7, AR-567 and PD-L1 mRNA) in EpCAM-positive CTCs compared to plasma-derived exosomes. GSTP1, RASSF1A and SCHLAFEN were methylated both in CTC and exosomes. In CTCs, Kaplan–Meier analysis revealed that CK-19 (p = 0.009), PSMA (p = 0.001), TWIST1 (p = 0.001) expression and GSTP1 (p = 0.001) methylation were correlated with OS, while in exosomes GSTP1 (p = 0.007) and RASSF1A (p = 0.001) methylation was correlated with OS. Our direct comparison study of CTCs and exosomes at gene expression and DNA methylation level, revealed for the first time a significantly higher positivity in EpCAM-positive CTCs compared to plasma-derived exosomes. Future perspective of this study should be the evaluation of clinical utility of molecular biomarkers in CTCs and exosomes on independent multicentric cohorts with mCRPC patients.

scholarly journals Reconstructing Promoter Activity From Lux Bioluminescent Reporters

2017 ◽  
Author(s):  
Mudassar Iqbal ◽  
Neil Doherty ◽  
Anna M.L. Page ◽  
Saara N.A. Qazi ◽  
Ishan Ajmera ◽  
...  
Keyword(s):  
Gene Expression ◽  
High Frequency ◽  
Promoter Activity ◽  
Light Output ◽  
Bacterial Cells ◽  
Correct Interpretation ◽  
Enzyme Dynamics ◽  
First Time ◽  
Non Destructive ◽  
Modelling Approach

AbstractThe bacterial Lux system is used as a gene expression reporter. It is fast, sensitive and non-destructive, enabling high frequency measurements. Originally developed for bacterial cells, it has been adapted for eukaryotic cells, and can be used for whole cell biosensors, or in real time with live animals without the need for slaughter. However, correct interpretation of bioluminescent data is limited: the bioluminescence is different from gene expression because of nonlinear molecular and enzyme dynamics of the Lux system. We have developed a modelling approach that, for the first time, allows users of Lux assays to infer gene transcription levels from the light output. We show examples where a decrease in bioluminescence would be better interpreted as a switching off of the promoter, or where an increase in bioluminescence would be better interpreted as a longer period of gene expression. This approach could benefit all users of Lux technology.

Directed De Novo DNA Methylation of a Genomic Locus Leads to Heritable Transcriptional Repression.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 343-343
Author(s):  
Kevin G. Ford ◽  
Paul J. Hurd ◽  
Andrew J. Bannister ◽  
Tony Kouzarides ◽  
Alexander E. Smith
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Transcriptional Repression ◽  
Cytosine Methylation ◽  
De Novo ◽  
Genomic Locus ◽  
Repressive Chromatin ◽  
First Time ◽  
Dna Cytosine Methylation ◽  
De Novo Methylation

Abstract The ability to impose exogenous targeted epigenetic changes in the genome represents an attractive goal in gene therapy for the heritable repression of target genes, while potentially enabling the generation and subsequent study of the downstream effects of de novo epigenetic events, which are known to occur in disease. Here we demonstrate the ability of zinc-finger peptides to deliver DNA cytosine methylation in vivo to a genomic target promoter, when expressed as fusions with a mutant prokaryotic DNA cytosine methyltransferase enzyme, thus mimicking cellular de novo methylation events. We show for the first time targeted gene silencing in response to directed DNA cytosine methylation via initiation of a repressive chromatin signature at a targeted genomic locus, characterised by elevation of histone H3K9Me2 and reduction of H3K4Me3 levels at that region. This transcriptional repression is maintained in the absence of sustained targeted methyltransferase action, confirming epigenetic maintenance by the cells own machinery. The inherited DNA methylation pattern is restricted to specific target sites, suggesting that the establishment of repressive chromatin structure does not drive further de novo DNA methylation in this system. Therefore, we demonstrate for the first time, targeted DNA methyltransferases as potential tools for the exogenous and heritable control of gene expression at the chromosomal level, while providing the clearest and most direct confirmation to date of the functional and mechanistic consequences of de novo DNA methylation in the cell. This work represents an important step towards the longer term goal of controlling gene expression through the inheritance of a repressive DNA state, as well as providing a valuable tool for studying spatial and temporal issues associated with ‘genuine’ de novo methylation, on transcription and chromatin structure.

scholarly journals Epigenetic MRI: Noninvasive Imaging of DNA Methylation in the Brain

2021 ◽  
Author(s):  
Fan Lam ◽  
James Chu ◽  
Ji Sun Choi ◽  
Chang Cao ◽  
T. Kevin Hitchens ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Magnetic Resonance ◽  
Brain Function ◽  
Major Gene ◽  
Noninvasive Imaging ◽  
Intact Brain ◽  
Genetic Mechanisms ◽  
Methyl Cytosine ◽  
First Time

It has been recognized that an integration of neuronal and genetic mechanisms supports brain function, regulates behaviour, and underpins response to environmental or disease stimuli. Several different technologies are available for imaging and studying neuronal activity in living brains, such as functional magnetic resonance imaging (fMRI), and have been translated to humans. However, the tools available to measure gene expression are destructive. Here we present a method, called epigenetic MRI (eMRI), that overcomes this limitation. eMRI achieves for the first time direct and noninvasive imaging of DNA methylation, a major gene expression regulator, in intact brains. eMRI exploits the methionine metabolic pathways that are responsible for DNA methylation to label the methyl-cytosine in brain genomic DNA through carbon-13 enriched diets. It then uses a novel carbon-13 magnetic resonance spectroscopic imaging (13C-MRSI) method to map the spatial distribution of labeled DNA. We demonstrated successful 13C labeling of brain DNA through diet using mass spectrometry, and robust and specific detection of labeled DNA using 13C-MRSI. We used eMRI and a biomedical piglet model to produce the first DNA methylation map of an intact brain hemisphere. With both noninvasive labeling and imaging, we expect eMRI to be readily translated to humans and thus enable many new investigations into the epigenetic basis of brain function, behavior, and disease.

DNA Methylation Inhibites ANXA1 Gene Expression in Nasopharyngeal Carcinoma Cell Lines*

2009 ◽  
Vol 36 (10) ◽  
pp. 1319-1326 ◽  
Author(s):  
Shuang-Xiang TAN ◽  
Rui-Cheng HU ◽  
Ai-Guo DAI ◽  
Cen-E TANG ◽  
Hong YI ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Nasopharyngeal Carcinoma ◽  
Cell Lines ◽  
Carcinoma Cell ◽  
Nasopharyngeal Carcinoma Cell ◽  
Carcinoma Cell Lines
Sign in / Sign up

Export Citation Format

Share Document