scholarly journals Epigenetic machinery is functionally conserved in cephalopods

2021 ◽  
Author(s):  
Filippo Macchi ◽  
Eric Edsinger ◽  
Kirsten C Sadler
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Methylation Pattern ◽  
Model Organisms ◽  
Specific Gene ◽  
Molecular Approaches ◽  
Maintenance Factors ◽  
Epigenetic Machinery ◽  
Static Pattern ◽  
Identify Gene Expression

Epigenetic regulatory mechanisms are divergent across the animal kingdom, yet little is known about the epigenome in non-model organisms. Unique features of cephalopods make them attractive for investigating behavioral, sensory, developmental and regenerative processes, but using molecular approaches in such studies is hindered by the lack of knowledge about genome organization and gene regulation in these animals. We combined bioinformatic and molecular analysis of Octopus bimaculoides to identify gene expression signatures for 12 adult tissues and a hatchling, and investigate the presence and pattern of DNA methylation and histone methylation marks across tissues. This revealed a dynamic gene expression profile encoding several epigenetic regulators, including DNA methylation maintenance factors that were highly conserved and functional in cephalopods, as shown by detection of 5-methyl-cytosine in multiple tissues of octopus, squid and bobtail squid. WGBS of octopus brain and RRBS from a hatchling revealed that less than 10% of CpGs are methylated, highlighting a non-random distribution in the genome of all tissues, with enrichment in the bodies of a subset of 14,000 genes and absence from transposons. Each DNA methylation pattern encompassed genes with distinct functions and, strikingly, many of these genes showed similar expression levels across tissues. In contrast to the static pattern of DNA methylation, the histone marks H3K27me3, H3K9me3 and H3K4me3 were detected at different levels in diverse cephalopod tissues. This suggests the methylome and histone code cooperate to regulate tissue specific gene expression in a way that may be unique to cephalopods.

scholarly journals Evolutionary History of DNA Methylation Related Genes in Bivalvia: New Insights From Mytilus galloprovincialis

2021 ◽  
Vol 9 ◽  
Author(s):  
Marco Gerdol ◽  
Claudia La Vecchia ◽  
Maria Strazzullo ◽  
Pasquale De Luca ◽  
Stefania Gorbi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Mytilus Galloprovincialis ◽  
Adult Life ◽  
Dna Methyltransferases ◽  
Methylation Pattern ◽  
Epigenetic Mechanism ◽  
Specific Gene ◽  
Fundamental Information ◽  
Genome Activity

DNA methylation is an essential epigenetic mechanism influencing gene expression in all organisms. In metazoans, the pattern of DNA methylation changes during embryogenesis and adult life. Consequently, differentiated cells develop a stable and unique DNA methylation pattern that finely regulates mRNA transcription during development and determines tissue-specific gene expression. Currently, DNA methylation remains poorly investigated in mollusks and completely unexplored in Mytilus galloprovincialis. To shed light on this process in this ecologically and economically important bivalve, we screened its genome, detecting sequences homologous to DNA methyltransferases (DNMTs), methyl-CpG-binding domain (MBD) proteins and Ten-eleven translocation methylcytosine dioxygenase (TET) previously described in other organisms. We characterized the gene architecture and protein domains of the mussel sequences and studied their phylogenetic relationships with the ortholog sequences from other bivalve species. We then comparatively investigated their expression levels across different adult tissues in mussel and other bivalves, using previously published transcriptome datasets. This study provides the first insights on DNA methylation regulators in M. galloprovincialis, which may provide fundamental information to better understand the complex role played by this mechanism in regulating genome activity in bivalves.

Examination of the dynamics of global DNA methylation pattern establishment during spermatogenesiss

2007 ◽  
Vol 30 (4) ◽  
pp. 90
Author(s):  
Kirsten Niles ◽  
Sophie La Salle ◽  
Christopher Oakes ◽  
Jacquetta Trasler
Keyword(s):  
Dna Methylation ◽  
Germ Cell ◽  
Germ Cells ◽  
Epigenetic Modification ◽  
Methylation Pattern ◽  
Chromosome 9 ◽  
Specific Gene ◽  
Global Methylation ◽  
Dna Methylation Pattern ◽  
Methylation Patterns

Background: DNA methylation is an epigenetic modification involved in gene expression, genome stability, and genomic imprinting. In the male, methylation patterns are initially erased in primordial germ cells (PGCs) as they enter the gonadal ridge; methylation patterns are then acquired on CpG dinucleotides during gametogenesis. Correct pattern establishment is essential for normal spermatogenesis. To date, the characterization and timing of methylation pattern acquisition in PGCs has been described using a limited number of specific gene loci. This study aimed to describe DNA methylation pattern establishment dynamics during male gametogenesis through global methylation profiling techniques in a mouse model. Methods: Using a chromosome based approach, primers were designed for 24 regions spanning chromosome 9; intergenic, non-repeat, non-CpG island sequences were chosen for study based on previous evidence that these types of sequences are targets for testis-specific methylation events. The percent methylation was determined in each region by quantitative analysis of DNA methylation using real-time PCR (qAMP). The germ cell-specific pattern was determined by comparing methylation between spermatozoa and liver. To examine methylation in developing germ cells, spermatogonia from 2 day- and 6 day-old Oct4-GFP (green fluorescent protein) mice were isolated using fluorescence activated cell sorting. Results: As compared to liver, four loci were hypomethylated and five loci were hypermethylated in spermatozoa, supporting previous results indicating a unique methylation pattern in male germ cells. Only one region was hypomethylated and no regions were hypermethylated in day 6 spermatogonia as compared to mature spermatozoa, signifying that the bulk of DNA methylation is established prior to type A spermatogonia. The methylation in day 2 spermatogonia, germ cells that are just commencing mitosis, revealed differences of 15-20% compared to day 6 spermatogonia at five regions indicating that the most crucial phase of DNA methylation acquisition occurs prenatally. Conclusion: Together, these studies provide further evidence that germ cell methylation patterns differ from those in somatic tissues and suggest that much of methylation at intergenic sites is acquired during prenatal germ cell development. (Supported by CIHR)

scholarly journals Curcumin from Turmeric Rhizome: A Potential Modulator of DNA Methylation Machinery in Breast Cancer Inhibition

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 332
Author(s):  
Krystyna Fabianowska-Majewska ◽  
Agnieszka Kaufman-Szymczyk ◽  
Aldona Szymanska-Kolba ◽  
Jagoda Jakubik ◽  
Grzegorz Majewski ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Dna Methylation ◽  
Curcuma Longa ◽  
Cancer Chemoprevention ◽  
Methylation Pattern ◽  
Dna Demethylation ◽  
Perennial Herb ◽  
Epigenetic Events ◽  
Epigenetic Machinery ◽  
Breast Cancer Inhibition

One of the most systematically studied bioactive nutraceuticals for its benefits in the management of various diseases is the turmeric-derived compounds: curcumin. Turmeric obtained from the rhizome of a perennial herb Curcuma longa L. is a condiment commonly used in our diet. Curcumin is well known for its potential role in inhibiting cancer by targeting epigenetic machinery, with DNA methylation at the forefront. The dynamic DNA methylation processes serve as an adaptive mechanism to a wide variety of environmental factors, including diet. Every healthy tissue has a precise DNA methylation pattern that changes during cancer development, forming a cancer-specific design. Hypermethylation of tumor suppressor genes, global DNA demethylation, and promoter hypomethylation of oncogenes and prometastatic genes are hallmarks of nearly all types of cancer, including breast cancer. Curcumin has been shown to modulate epigenetic events that are dysregulated in cancer cells and possess the potential to prevent cancer or enhance the effects of conventional anti-cancer therapy. Although mechanisms underlying curcumin-mediated changes in the epigenome remain to be fully elucidated, the mode of action targeting both hypermethylated and hypomethylated genes in cancer is promising for cancer chemoprevention. This review provides a comprehensive discussion of potential epigenetic mechanisms of curcumin in reversing altered patterns of DNA methylation in breast cancer that is the most commonly diagnosed cancer and the leading cause of cancer death among females worldwide. Insight into the other bioactive components of turmeric rhizome as potential epigenetic modifiers has been indicated as well.

scholarly journals Genome-wide variation in DNA methylation linked to developmental stage and chromosomal suppression of recombination in white-throated sparrows

2020 ◽  
Author(s):  
Dan Sun ◽  
Thomas S. Layman ◽  
Hyeonsoo Jeong ◽  
Paramita Chatterjee ◽  
Kathleen Grogan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Chromosome Pair ◽  
Dna Methyltransferases ◽  
Model Organisms ◽  
Phenotypic Traits ◽  
Zonotrichia Albicollis ◽  
Single Nucleotide ◽  
Genome Wide ◽  
Nucleotide Resolution

ABSTRACTDNA methylation is known to play critical roles in key biological processes. Most of our knowledge on regulatory impacts of DNA methylation has come from laboratory-bred model organisms, which may not exhibit the full extent of variation found in wild populations. Here, we investigated naturally-occurring variation in DNA methylation in a wild avian species, the white-throated sparrow (Zonotrichia albicollis). This species offers exceptional opportunities for studying the link between genetic differentiation and phenotypic traits because of a non-recombining chromosome pair linked to both plumage and behavioral phenotypes. Using novel single-nucleotide resolution methylation maps and gene expression data, we show that DNA methylation and the expression of DNA methyltransferases are significantly higher in adults than in nestlings. Genes for which DNA methylation varied between nestlings and adults were implicated in development and cell differentiation and were located throughout the genome. In contrast, differential methylation between plumage morphs was localized to the non-recombining chromosome pair. One subset of CpGs on the non-recombining chromosome was extremely hypomethylated and localized to transposable elements. Changes in methylation predicted changes in gene expression for both chromosomes. In summary, we demonstrate changes in genome-wide DNA methylation that are associated with development and with specific functional categories of genes in white-throated sparrows. Moreover, we observe substantial DNA methylation reprogramming associated with the suppression of recombination, with implications for genome integrity and gene expression divergence. These results offer an unprecedented view of ongoing epigenetic reprogramming in a wild population.

scholarly journals Methylation pattern polymorphism of cyp19a in Nile tilapia and hybrids

2018 ◽  
Vol 13 (1) ◽  
pp. 327-334 ◽  
Author(s):  
Xiaowu Chen ◽  
Yonghua Zhao ◽  
Yudong He ◽  
Jinliang Zhao
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Methylation Level ◽  
Molecular Mechanisms ◽  
Methylation Pattern ◽  
Male Ratio ◽  
Sex Development ◽  
Pattern Polymorphism ◽  
Fish Hybrids

AbstractSkewed sex development is prevalent in fish hybrids. However, the histological observation and molecular mechanisms remain elusive. In this study, we showed that the interspecific hybrids of the two fish species, Oreochromis niloticus and Oreochromis aureus, had a male ratio of 98.02%. Microscopic examination revealed that the gonads of both male and female hybrids were developmentally retarded. Compared with the ovaries, the testes of both O. niloticus and hybrids showed higher DNA methylation level in two selected regions in the promoter of cyp19a, the gonadal aromatase gene that converts androgens into estrogens, cyp19a showed higher level gene expression in the ovary than in the testis in both O. niloticus and hybrid tilapia. Methylation and gene expression level of cyp19a were negative correlation between the testis and ovary. Gene transcription was suppressed by the methylation of the cyp19a promoter in vitro. While there is no obvious difference of the methylation level in testis or ovary between O. niloticus and hybrids. Thus, the DNA methylation of the promoter of cyp19a may be an essential component of the sex maintenance, but not a determinant of high male ratio and developmental retardation of gonads in tilapia hybrids.

DNA methylation versus gene expression

Development ◽  
1984 ◽  
Vol 83 (Supplement) ◽  
pp. 31-40
Author(s):  
Adrian P. Bird
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Cell Division ◽  
Methylation Pattern ◽  
Current Evidence ◽  
Evolutionary Perspective ◽  
Cell Type ◽  
Versus Gene ◽  
Daughter Cells ◽  
The Relationship

Vertebrate DNA is methylated at a high proportion of cytosine residues in the sequence CpG, and it has been suggested that the distribution of methylated and non-methylated CpGs in a given cell type influences the pattern of gene expression in those cells. Since a DNA methylation pattern is normally transmitted faithfully to daughter cells via cell division, this idea suggests an origin for stable, clonally inherited patterns of gene expression. This article discusses some of the current evidence for a relationship between DNA methylation and gene expression. Although the evidence is incomplete, it appears already that the relationship is variable: transcription of some genes is repressed by the presence of 5-methylcytosine at certain CpGs, and may be controlled by methylation, while transcription of other genes is indifferent to methylation. In attempting to explain this variability it is helpful to adopt an evolutionary perspective.

scholarly journals Impact of Transposable Elements on Methylation and Gene Expression across Natural Accessions of Brachypodium distachyon

2020 ◽  
Vol 12 (11) ◽  
pp. 1994-2001 ◽  
Author(s):  
Michele Wyler ◽  
Christoph Stritt ◽  
Jean-Claude Walser ◽  
Célia Baroux ◽  
Anne C Roulin
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Transposable Elements ◽  
Brachypodium Distachyon ◽  
Large Fraction ◽  
Expression Patterns ◽  
Specific Gene ◽  
Differential Gene ◽  
The Relationship ◽  
Silent State

Abstract Transposable elements (TEs) constitute a large fraction of plant genomes and are mostly present in a transcriptionally silent state through repressive epigenetic modifications, such as DNA methylation. TE silencing is believed to influence the regulation of adjacent genes, possibly as DNA methylation spreads away from the TE. Whether this is a general principle or a context-dependent phenomenon is still under debate, pressing for studying the relationship between TEs, DNA methylation, and nearby gene expression in additional plant species. Here, we used the grass Brachypodium distachyon as a model and produced DNA methylation and transcriptome profiles for 11 natural accessions. In contrast to what is observed in Arabidopsis thaliana, we found that TEs have a limited impact on methylation spreading and that only few TE families are associated with a low expression of their adjacent genes. Interestingly, we found that a subset of TE insertion polymorphisms is associated with differential gene expression across accessions. Thus, although not having a global impact on gene expression, distinct TE insertions may contribute to specific gene expression patterns in B. distachyon.

scholarly journals CRISPR-mediated modification of DNA methylation pattern in the new era of cancer therapy

Epigenomics ◽  
2020 ◽  
Vol 12 (20) ◽  
pp. 1845-1859
Author(s):  
Faezeh Maroufi ◽  
Amirhosein Maali ◽  
Meghdad Abdollahpour-Alitappeh ◽  
Mohammad Hossein Ahmadi ◽  
Mehdi Azad
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Cancer Progression ◽  
Methylation Pattern ◽  
Epigenetic Therapy ◽  
Special Importance ◽  
New Era ◽  
Major Mechanism ◽  
Aberrant Dna Methylation ◽  
Normal Status

In the last 2 decades, a wide variety of studies have been conducted on epigenetics and its role in various cancers. A major mechanism of epigenetic regulation is DNA methylation, including aberrant DNA methylation variations such as hypermethylation and hypomethylation in the promoters of critical genes, which are commonly detected in tumors and mark the early stages of cancer development. Therefore, epigenetic therapy has been of special importance in the last decade for cancer treatment. In epigenetic therapy, all efforts are made to modulate gene expression to the normal status. Importantly, recent studies have shown that epigenetic therapy is focusing on the new gene editing technology, CRISPR-Cas9. This tool was found to be able to effectively modulate gene expression and alter almost any sequence in the genome of cells, resulting in events such as a change in acetylation, methylation, or histone modifications. Of note, the CRISPR-Cas9 system can be used for the treatment of cancers caused by epigenetic alterations. The CRISPR-Cas9 system has greater advantages than other available methods, including potent activity, easy design and high velocity as well as the ability to target any DNA or RNA site. In this review, we described epigenetic modulators, which can be used in the CRISPR-Cas9 system, as well as their functions in gene expression alterations that lead to cancer initiation and progression. In addition, we surveyed various species of CRISPR-dead Cas9 (dCas9) systems, a mutant version of Cas9 with no endonuclease activity. Such systems are applicable in epigenetic therapy for gene expression modulation through chemical group editing on nucleosomes and chromatin remodeling, which finally return the cell to the normal status and prevent cancer progression.

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