scholarly journals 5-Azacytidine: A Promoter of Epigenetic Changes in the Quest to Improve Plant Somatic Embryogenesis

2018 ◽  
Vol 19 (10) ◽  
pp. 3182 ◽  
Author(s):  
Pedro Osorio-Montalvo ◽  
Luis Sáenz-Carbonell ◽  
Clelia De-la-Peña
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Somatic Embryogenesis ◽  
Regulation Of Gene Expression ◽  
Culture Conditions ◽  
Short Time ◽  
Time Frames ◽  
Different Sources

Somatic embryogenesis (SE) is a widely studied process due to its biotechnological potential to generate large quantities of plants in short time frames and from different sources of explants. The success of SE depends on many factors, such as the nature of the explant, the microenvironment generated by in vitro culture conditions, and the regulation of gene expression, among others. Epigenetics has recently been identified as an important factor influencing SE outcome. DNA methylation is one of the most studied epigenetic mechanisms due to its essential role in gene expression, and its participation in SE is crucial. DNA methylation levels can be modified through the use of drugs such as 5-Azacytidine (5-AzaC), an inhibitor of DNA methylation, which has been used during SE protocols. The balance between hypomethylation and hypermethylation seems to be the key to SE success. Here, we discuss the most prominent recent research on the role of 5-AzaC in the regulation of DNA methylation, highlighting its importance during the SE process. Also, the molecular implications that this inhibitor might have for the increase or decrease in the embryogenic potential of various explants are reviewed.

scholarly journals The impact of Piscirickettsia Salmonis infection on genome-wide DNA methylation profile in Atlantic Salmon

2021 ◽  
Author(s):  
Robert Mukiibi ◽  
Carolina Peñaloza ◽  
Alejandro Gutierrez ◽  
José M. Yáñez ◽  
Ross D. Houston ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Atlantic Salmon ◽  
Negative Correlation ◽  
Regulation Of Gene Expression ◽  
Head Kidney ◽  
Epigenetic Mechanism ◽  
Piscirickettsia Salmonis ◽  
The Impact

Salmon rickettsial septicaemia (SRS), caused by the intracellular bacteria Piscirickettsia Salmonis, generates significant mortalities to farmed Atlantic salmon, particularly in Chile. Due to its economic importance, a wealth of research has focussed on the biological mechanisms underlying pathogenicity of P. salmonis, the host response, and genetic variation in host resistance. DNA methylation is a fundamental epigenetic mechanism that influences almost every biological process via the regulation of gene expression and plays a key role in the response of an organism to stimuli. In the current study, the role of head kidney and liver DNA methylation in the response to P. salmonis infection was investigated in a commercial Atlantic salmon population. A total of 66 salmon were profiled using reduced representation bisulphite sequencing (RRBS), with head kidney and liver methylomes compared between infected animals (3 and 9 days post infection) and uninfected controls. These included groups of salmon with divergent (high or low) breeding values for resistance to P. salmonis infection, to examine the influence of genetic resistance. Head kidney and liver showed organ-specific global methylation patterns, but with similar distribution of methylation across gene features. Integration of methylation with RNA-Seq data revealed that methylation levels predominantly showed a negative correlation with gene expression, although positive correlations were also observed. Methylation within the first exon showed the strongest negative correlation with gene expression. A total of 911 and 813 differentially methylated CpG sites were identified between infected and control samples in the head kidney at 3 and 9 days respectively, whereas only 30 and 44 sites were differentially methylated in the liver. Differential methylation in the head kidney was associated with immunological processes such as actin cytoskeleton regulation, phagocytosis, endocytosis and pathogen associated pattern receptor signaling. We also identified 113 and 48 differentially methylated sites between resistant and susceptible fish in the head kidney and liver respectively. Our results contribute to the growing understanding of the role of methylation in regulation of gene expression and response to infectious diseases, and in particular reveal key immunological functions regulated by methylation in Atlantic salmon in response to P. salmonis.

scholarly journals DNA Methylation and Chromatin: Role(s) of Methyl-CpG-Binding Protein ZBTB38

2018 ◽  
Vol 11 ◽  
pp. 251686571881111 ◽  
Author(s):  
Maud de Dieuleveult ◽  
Benoit Miotto
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Transcription Factors ◽  
Dna Sequences ◽  
Mammalian Cells ◽  
Expression Patterns ◽  
Control Of Gene Expression ◽  
Methylated Dna

DNA methylation plays an essential role in the control of gene expression during early stages of development as well as in disease. Although many transcription factors are sensitive to this modification of the DNA, we still do not clearly understand how it contributes to the establishment of proper gene expression patterns. We discuss here the recent findings regarding the biological and molecular function(s) of the transcription factor ZBTB38 that binds methylated DNA sequences in vitro and in cells. We speculate how these findings may help understand the role of DNA methylation and DNA methylation–sensitive transcription factors in mammalian cells.

scholarly journals The role of epigenetic regulation in adaptive phenotypic plasticity of plants

2021 ◽  
Vol 78 (5) ◽  
pp. 347-359
Author(s):  
E.L. Kordyum ◽  
◽  
D.V. Dubyna ◽  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Phenotypic Plasticity ◽  
Epigenetic Regulation ◽  
Molecular Mechanisms ◽  
Regulation Of Gene Expression ◽  
Model Species ◽  
Wide Range ◽  
Adaptive Phenotypic Plasticity

In recent decades, knowledge about the role of epigenetic regulation of gene expression in plant responses to external stimuli and in adaptation of plants to adverse environmental fluctuations have extended significantly. DNA methylation is considered as the main molecular mechanism that provides genomic information and contributes to the understanding of the molecular basis of phenotypic variations based on epigenetic modifications. Unfortunately, the vast majority of research in this area has been performed on the model species Arabidopsis thaliana. The development of the methylation-sensitive amplified polymorphism (MSAP) method has made it possible to implement the large-scale detection of DNA methylation alterations in wild non-model and agricultural plants with large and highly repetitive genomes in natural and manipulated habitats. The article presents current information on DNA methylation in species of natural communities and crops and its importance in plant development and adaptive phenotypic plasticity, along with brief reviews of current ideas about adaptive phenotypic plasticity and epigenetic regulation of gene expression. The great potential of further studies of the epigenetic role in phenotypic plasticity of a wide range of non-model species in natural populations and agrocenoses for understanding the molecular mechanisms of plant existence in the changing environment in onto- and phylogeny, directly related to the key tasks of forecasting the effects of global warming and crop selection, is emphasized. Specific taxa of the Ukrainian flora, which, in authors’ opinion, are promising and interesting for this type of research, are recommended.

scholarly journals Nucleosome assembly and disassembly pathways

2020 ◽  
Author(s):  
A. Hatakeyama ◽  
R. Retureau ◽  
M. Pasi ◽  
B. Hartmann ◽  
C. Nogues ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Sequence ◽  
Base Pair ◽  
Regulation Of Gene Expression ◽  
Detailed Comparison ◽  
Nucleosome Assembly ◽  
Nucleosome Dynamics ◽  
Intermediate States

AbstractNucleosome assembly and disassembly play a central role in the regulation of gene expression. Here we use PhAST (Photochemical Analysis of Structural Transitions) to monitor at the base pair level, structural alterations induced all along DNA upon histone binding or release. By offering the first consistent, detailed comparison of nucleosome assembly and disassembly in vitro, we are able to reveal similarities and differences between the two processes. We identify multiple intermediate states characterised by specific PhAST signatures; revealing a complexity that goes beyond the known sequential events involving (H3-H4)2 tetramer and H2A-H2B heterodimers. Such signatures localise and quantify the extent of the asymmetry of DNA/histone interactions with respect to the nucleosome dyad. This asymmetry is therefore defined by the localisation and amplitude of the signals. The localisation of the signal is consistent between assembly and disassembly and dictated by the DNA sequence. However, the amplitude component of this asymmetry not only evolves during the assembly and disassembly but does so differently between the two processes.Understanding the regulation of gene expression requires a complete knowledge of nucleosome dynamics. Our unexpected observation of differences between assembly and disassembly opens up new avenues to define the role of the DNA sequence in these processes. Overall, we provide new insights into how the intrinsic properties of DNA are integrated into a holistic mechanism that controls chromatin structure.Statement of SignificanceThis manuscript addresses the question of nucleosome dissociation compares with association. We used PhAST which is a non-intrusive photochemical technique to follow nucleosome dynamics at base pair resolution. We observed structural asymmetry during nucleosome turnover. We also showed for the first time that the process of nucleosome dissociation is not a reversal of association. This asymmetry favours intermediate states involved in chromatin organisation suggesting novel models for the role of nucleosome turnover in the epigenetic regulation of gene expression.

scholarly journals Regulation of gene expression in endothelial cells: the role of human follicular fluid

2005 ◽  
Vol 34 (1) ◽  
pp. 37-46 ◽  
Author(s):  
R Gruemmer ◽  
L Klein-Hitpaß ◽  
J Neulen
Keyword(s):  
Gene Expression ◽  
Endothelial Cells ◽  
Granulosa Cells ◽  
Follicular Fluid ◽  
Regulation Of Gene Expression ◽  
Angiogenic Factors ◽  
Human Follicular Fluid ◽  
Angiopoietin 2

A precise regulation of angiogenesis is a prerequisite for an adequate maturation of ovarian follicles. Despite the production of vascular endothelial growth factor (VEGF) by granulosa cells in antral follicles, angiogenesis is restricted to the theca cell layer. The maturing follicle remains avascular before ovulation, implying regulatory mechanisms which prevent premature follicular vascularization. In order to investigate the role of follicular fluid and of granulosa cells in the regulation of endothelial gene expression, human umbilical vein endothelial cells (HUVECs) were incubated in vitro with media conditioned with human follicular fluid obtained from individual patients undergoing oocyte retrieval for in vitro fertilization procedures or with culture medium conditioned by human granulosa cells respectively. Using microarray technology, the gene expression pattern was compared between untreated monolayers of HUVECs and HUVECs treated either with follicular fluid or with granulosa cell conditioned media. We identified a total of 15 genes that were significantly up-regulated and 11 genes that were significantly down-regulated in endothelial cells treated with follicular fluid at least 2.5-fold in more than 70% of comparisons. Up-regulated genes involved in angiogenesis were the anti-angiogenic factors gro-beta (16.5-fold), angiopoietin-2 (3.9-fold), alpha-2-macroglobulin (24.3-fold) and the pro-angiogenic factors E-selectin (5.3-fold) and vascular cell adhesion molecule-1 (VCAM-1) (4.4-fold), whereas a significant down-regulation of the pro-angiogenic genes fibulin-5 (3.5-fold) and elastin (14.9-fold) could be observed. Culturing of HUVECs with conditioned medium from cultured human luteinized granulosa cells demonstrated a similar regulatory pattern of gene expression for fibulin-5, elastin, gro-beta, and E-selectin. The gene regulation in endothelial cells by follicular fluid could be confirmed by RT-PCR for gro-beta, angiopoietin-2, elastin, fibulin-5, and E-selectin. The present work reveals that compounds secreted by granulosa cells lead to the expression of anti-angiogenic factors on the transcript level in endothelial cells and thus could help to explain the temporal and spatial discrepancy between the high expression of VEGF and the restricted angiogenesis in the preovulatory follicle.

scholarly journals DNA Methylation, Epigenetics, and Evolution in Vertebrates: Facts and Challenges

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Annalisa Varriale
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Environmental Influence ◽  
Epigenetic Modification ◽  
Regulation Of Gene Expression ◽  
Entire Genome ◽  
Phenotypic Differences ◽  
Methylation Patterns ◽  
And Control

DNA methylation is a key epigenetic modification in the vertebrate genomes known to be involved in biological processes such as regulation of gene expression, DNA structure and control of transposable elements. Despite increasing knowledge about DNA methylation, we still lack a complete understanding of its specific functions and correlation with environment and gene expression in diverse organisms. To understand how global DNA methylation levels changed under environmental influence during vertebrate evolution, we analyzed its distribution pattern along the whole genome in mammals, reptiles and fishes showing that it is correlated with temperature, independently on phylogenetic inheritance. Other studies in mammals and plants have evidenced that environmental stimuli can promote epigenetic changes that, in turn, might generate localized changes in DNA sequence resulting in phenotypic effects. All these observations suggest that environment can affect the epigenome of vertebrates by generating hugely different methylation patterns that could, possibly, reflect in phenotypic differences. We are at the first steps towards the understanding of mechanisms that underlie the role of environment in molding the entire genome over evolutionary times. The next challenge will be to map similarities and differences of DNA methylation in vertebrates and to associate them with environmental adaptation and evolution.

Epigenetic regulation mechanisms of microRNA expression

2017 ◽  
Vol 8 (5-6) ◽  
pp. 203-212 ◽  
Author(s):  
Sara Morales ◽  
Mariano Monzo ◽  
Alfons Navarro
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Cell Proliferation ◽  
Epigenetic Regulation ◽  
Regulation Of Gene Expression ◽  
Transcriptional Level ◽  
Regulate Gene Expression ◽  
Regulation Mechanisms ◽  
Regulate Gene

AbstractMicroRNAs (miRNAs) are single-stranded RNAs of 18–25 nucleotides that regulate gene expression at the post-transcriptional level. They are involved in many physiological and pathological processes, including cell proliferation, apoptosis, development and carcinogenesis. Because of the central role of miRNAs in the regulation of gene expression, their expression needs to be tightly controlled. Here, we summarize the different mechanisms of epigenetic regulation of miRNAs, with a particular focus on DNA methylation and histone modification.

scholarly journals FOXA1 plays a role in regulating secretoglobin 1a1 expression in the absence of CCAAT/enhancer binding protein activities in lung in vivo

2011 ◽  
Vol 300 (3) ◽  
pp. L441-L452 ◽  
Author(s):  
Taketomo Kido ◽  
Takeshi Tomita ◽  
Minoru Okamoto ◽  
Yan Cai ◽  
Yoshimi Matsumoto ◽  
...  
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Regulation Of Gene Expression ◽  
Dominant Negative ◽  
Clara Cell ◽  
Small Molecular Weight ◽  
Dominant Negative Form

Secretoglobin (SCGB) 1A1, also called Clara cell secretor protein (CCSP) or Clara cell-specific 10-kDa protein (CC10), is a small molecular weight secreted protein mainly expressed in lung, with anti-inflammatory/immunomodulatory properties. Previous in vitro studies demonstrated that CCAAT/enhancer-binding proteins (C/EBPs) are the major transcription factors for the regulation of Scbg1a1 gene expression, whereas FOXA1 had a minimum effect on the transcription. To determine the in vivo role of C/EBPs in the regulation of SCGB1A1 expression, experiments were performed in which A-C/EBP, a dominant-negative form of C/EBP that interferes with DNA binding activities of all C/EBPs, was specifically expressed in lung. Surprisingly, despite the in vitro findings, expression of SCGB1A1 mRNA was not decreased in vivo in the absence of C/EBPs. This may be due to a compensatory role assumed by FOXA1 in the regulation of Scgb1a1 gene expression in lung in the absence of active C/EBPs. This disconnect between in vitro and in vivo results underscores the importance of studies using animal models to determine the role of specific transcription factors in the regulation of gene expression in intact multicellular complex organs such as lung.

scholarly journals DNA methylation of genes in adipose tissue

2010 ◽  
Vol 70 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Katherine E. Pinnick ◽  
Fredrik Karpe
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Adipose Tissue ◽  
Body Fat ◽  
White Adipose Tissue ◽  
Regional Differences ◽  
Protein Modification ◽  
Regulation Of Gene Expression ◽  
Lower Body

Body fat distribution plays an important role in determining metabolic health. Whereas central obesity is closely associated with the development of CVD and type 2 diabetes, lower body fat appears to be protective and is paradoxically associated with improved metabolic and cardiovascular profiles. Physiological studies have demonstrated that fatty acid handling differs between white adipose tissue depots, with lower body white adipose tissue acting as a more efficient site for long-term lipid storage. The regulatory mechanisms governing these regional differences in function remain to be elucidated. Although the local microenvironment is likely to be a contributing factor, recent findings point towards the tissues being intrinsically distinct at the level of the adipocyte precursor cells (pre-adipocytes). The multi-potent pre-adipocytes are capable of generating cells of the mesenchymal lineage, including adipocytes. Regional differences in the adipogenic and replicative potential of these cells, as well as metabolic and biochemical activity, have been reported. Intriguingly, the genetic and metabolic characteristics of these cells can be retained through multiple generations when the cells are cultured in vitro. The rapidly emerging field of epigenetics may hold the key for explaining regional differences in white adipose tissue gene expression and function. Epigenetics describes the regulation of gene expression that occurs independently of changes in DNA sequence, for instance, DNA methylation or histone protein modification. In this review, we will discuss the contribution of DNA methylation to the determination of cells of adipogenic fate as well as the role DNA methylation may play during adipocyte terminal differentiation.

scholarly journals DNA methylation and regulation of gene expression: Guardian of our health

The Nucleus ◽  
2021 ◽  
Author(s):  
Gaurab Aditya Dhar ◽  
Shagnik Saha ◽  
Parama Mitra ◽  
Ronita Nag Chaudhuri
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Regulation Of Gene Expression
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