scholarly journals Genome-wide DNA methylation alterations of Alternanthera philoxeroides in natural and manipulated habitats: implications for epigenetic regulation of rapid responses to environmental fluctuation and phenotypic variation

2010 ◽  
Vol 33 (11) ◽  
pp. 1820-1827 ◽  
Author(s):  
LEXUAN GAO ◽  
YUPENG GENG ◽  
BO LI ◽  
JIAKUAN CHEN ◽  
JI YANG
Keyword(s):  
Dna Methylation ◽  
Epigenetic Regulation ◽  
Phenotypic Variation ◽  
Alternanthera Philoxeroides ◽  
Environmental Fluctuation ◽  
Rapid Responses ◽  
Genome Wide

scholarly journals DNA hypermethylation associated with upregulated gene expression in prostate cancer demonstrates the diversity of epigenetic regulation

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Ieva Rauluseviciute ◽  
Finn Drabløs ◽  
Morten Beck Rye
Keyword(s):  
Gene Expression ◽  
Prostate Cancer ◽  
Dna Methylation ◽  
Epigenetic Regulation ◽  
Normal Tissue ◽  
Expression Profiles ◽  
Expression Data ◽  
Dna Hypermethylation ◽  
Genome Wide ◽  
A Genome

Abstract Background Prostate cancer (PCa) has the highest incidence rates of cancers in men in western countries. Unlike several other types of cancer, PCa has few genetic drivers, which has led researchers to look for additional epigenetic and transcriptomic contributors to PCa development and progression. Especially datasets on DNA methylation, the most commonly studied epigenetic marker, have recently been measured and analysed in several PCa patient cohorts. DNA methylation is most commonly associated with downregulation of gene expression. However, positive associations of DNA methylation to gene expression have also been reported, suggesting a more diverse mechanism of epigenetic regulation. Such additional complexity could have important implications for understanding prostate cancer development but has not been studied at a genome-wide scale. Results In this study, we have compared three sets of genome-wide single-site DNA methylation data from 870 PCa and normal tissue samples with multi-cohort gene expression data from 1117 samples, including 532 samples where DNA methylation and gene expression have been measured on the exact same samples. Genes were classified according to their corresponding methylation and expression profiles. A large group of hypermethylated genes was robustly associated with increased gene expression (UPUP group) in all three methylation datasets. These genes demonstrated distinct patterns of correlation between DNA methylation and gene expression compared to the genes showing the canonical negative association between methylation and expression (UPDOWN group). This indicates a more diversified role of DNA methylation in regulating gene expression than previously appreciated. Moreover, UPUP and UPDOWN genes were associated with different compartments — UPUP genes were related to the structures in nucleus, while UPDOWN genes were linked to extracellular features. Conclusion We identified a robust association between hypermethylation and upregulation of gene expression when comparing samples from prostate cancer and normal tissue. These results challenge the classical view where DNA methylation is always associated with suppression of gene expression, which underlines the importance of considering corresponding expression data when assessing the downstream regulatory effect of DNA methylation.

1 Whole-genome bisulfite sequencing of bovine gametes and invivo-produced pre-implantation embryos

2019 ◽  
Vol 31 (1) ◽  
pp. 126
Author(s):  
J. E. Duan ◽  
Z. Jiang ◽  
F. Alqahtani ◽  
I. Mandoiu ◽  
H. Dong ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Single Cell ◽  
Epigenetic Regulation ◽  
Bisulfite Sequencing ◽  
Whole Genome ◽  
Differentially Methylated Regions ◽  
Whole Genome Bisulfite Sequencing ◽  
Cpg Sites ◽  
Genome Wide ◽  
Genome Bisulfite Sequencing

Dynamic changes in DNA methylation are crucial in the epigenetic regulation of mammalian embryogenesis. Global DNA methylation studies in the bovine, however, remain mostly at the immunostaining level. We adopted the single-cell whole-genome bisulfite sequencing method to characterise stage-specific genome-wide DNA methylation in bovine sperm, individual oocytes derived invivo and invitro, and invivo-developed embryos at the 2-, 4-, 8-, and 16-cell stages. This method allowed us to theoretically cover all CpG sites in the genome using a limited number of cells from single embryos. Pools of 20 sperm were selected from a bull with proven fertility. Single oocytes (n=6) and embryos (n=4 per stage) were collected from Holstein cows (n=10). Single-cell whole-genome bisulfite sequencing libraries were prepared and sequenced using the Illumina HiSEqn 4000 platform (Illumina, San Diego, CA, USA). Sequencing reads were filtered and aligned to the bovine reference genome (UMD 3.1.1) using Bismark (Krueger and Andrews 2011Bioinformatics27, 1571-1572, DOI: 10.1093/bioinformatics/btr167).A 300-bp tile-based method was applied to bin the genome into consecutive windows to facilitate comparison across samples. The DNA methylation level was calculated as the fraction of read counts of the total number of cytosines (methylated) in the total read counts of reported cytosines and thymines (methylated and unmethylated), only if more than 3 CpG sites were covered in this tile. Gamete-specific differentially methylated regions were identified when DNA methylation levels were greater than 75% in one type of gamete and less than 25% in the other with false discovery rate-corrected Fisher’s exact test P-values of less than 0.05. The major wave of genome-wide DNA demethylation was complete at the 8-cell stage when de novo methylation became prominent. Sperm and oocytes had numerous differentially methylated regions that were enriched in intergenic regions. Differentially methylated regions were also identified between invivo- and invitro-matured oocytes. Moreover, X chromosome methylation followed the global dynamic patterns. Virtually no (less than 1.5%) DNA methylation was found in mitochondrial DNA. Finally, using our RNA sequencing data generated from the same developmental stages (Jiang et al. 2014 BMC Genomics 15, 756; DOI: 10.1186/1471-2164-15-756), we revealed an inverse correlation between gene expression and promoter methylation. Our study provides the first fully comprehensive analysis of the global dynamics of DNA methylation in bovine gametes and single early embryos using single-cell whole-genome bisulfite sequencing. These data provide insights into the critical features of the methylome of bovine embryos and serve as an important reference for embryos produced by assisted reproduction, such as IVF and cloning, and a model for human early embryo epigenetic regulation.

scholarly journals Genome-wide sampling suggests island divergence accompanied by cryptic epigenetic plasticity in Canada lynx

2018 ◽  
Author(s):  
J.B. Johnson ◽  
D.L. Murray ◽  
A.B.A. Shafer
Keyword(s):  
Dna Methylation ◽  
Gene Flow ◽  
Genetic Differentiation ◽  
Genetic Markers ◽  
Phenotypic Variation ◽  
Lynx Canadensis ◽  
Functional Plasticity ◽  
Canada Lynx ◽  
Last Glaciation ◽  
Genome Wide

ABSTRACTDetermining the molecular signatures of adaptive differentiation is a fundamental component of evolutionary biology. A key challenge remains for identifying such signatures in wild organisms, particularly between populations of highly mobile species that undergo substantial gene flow. The Canada lynx (Lynx canadensis) is one species where mainland populations appear largely undifferentiated at traditional genetic markers, despite inhabiting diverse environments and displaying phenotypic variation. Here, we used high-throughput sequencing to investigate both neutral genetic structure and epigenetic differentiation across the distributional range of Canada lynx. Using a customized bioinformatics pipeline we scored both neutral SNPs and methylated nucleotides across the lynx genome. Newfoundland lynx were identified as the most differentiated population at neutral genetic markers, with diffusion approximations of allele frequencies indicating that divergence from the panmictic mainland occurred at the end of the last glaciation, with minimal contemporary admixture. In contrast, epigenetic structure revealed hidden levels of differentiation across the range coincident with environmental determinants including winter conditions, particularly in the peripheral Newfoundland and Alaskan populations. Several biological pathways related to morphology were differentially methylated between populations, with Newfoundland being disproportionately methylated for genes that could explain the observed island dwarfism. Our results indicate that epigenetic modifications, specifically DNA methylation, are powerful markers to investigate population differentiation and functional plasticity in wild and non-model systems.SIGNIFICANCEPopulations experiencing high rates of gene flow often appear undifferentiated at neutral genetic markers, despite often extensive environmental and phenotypic variation. We examined genome-wide genetic differentiation and DNA methylation between three interconnected regions and one insular population of Canada lynx (Lynx canadensis) to determine if epigenetic modifications characterized climatic associations and functional molecular plasticity. Demographic approximations indicated divergence of Newfoundland during the last glaciation, while cryptic epigenetic structure identified putatively functional differentiation that might explain island dwarfism. Our study suggests that DNA methylation is a useful marker for differentiating wild populations, particularly when faced with functional plasticity and low genetic differentiation.

scholarly journals Epigenetic modifications and their role in the development and disease progression of type 2 diabetes

2021 ◽  
Vol 8 (2) ◽  
pp. 948
Author(s):  
Abhijeet Roy
Keyword(s):  
Type 2 Diabetes ◽  
Dna Methylation ◽  
Epigenetic Regulation ◽  
Association Studies ◽  
Normal Subjects ◽  
Genome Wide Association Studies ◽  
Non Coding Rna ◽  
Genome Wide ◽  
Methylation Patterns

Type 2 Diabetes is one of the major public health issues and a complex metabolic disorder strongly associated with genetic predisposition influenced by environmental factors and epigenetic regulation. This review paper illustrated the role of epigenetics in the pathogenesis, progression, and detection of Type 2 Diabetes. A review study was performed for the articles published in English from 2000-2019 using Pub Med, and Google Scholar databases. Main underlining mechanisms of Type 2 Diabetes were identified; insulin resistance in the peripheral tissue, and disintegrate insulin secretion. Genome Wide Association Studies suggested that epigenetic regulation such as DNA methylation, Histone modification, Non-coding RNA, microRNA is strongly related with the development of Type 2 Diabetes. Altered DNA methylation patterns in pancreatic islets, skeletal muscle, adipose tissue, from diabetic subjects compare to normal subjects was also found. Other risk factors like; obesity, age, gender, impaired glucose tolerance, periconception and intrauterine environment may also have been linked with the possibilities of epigenetic changes. Epigenetics plays a crucial role by modifying the gene expression and establish a relationship between the environment and genetic factors. Understanding the epigenetic mechanisms contributing to the development of Type 2 Diabetes is still limited.

Integrated Genetic and Epigenetic Analysis of Childhood Acute Lymphoblastic Leukemia Reveals a Synergistic Role for Structural and Epigenetic Lesions In Determining Disease Phenotype

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 537-537
Author(s):  
Maria E. Figueroa ◽  
Shann-Ching Chen ◽  
Anna K. Andersson ◽  
Wei Liu ◽  
Cheng Cheng ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Acute Lymphoblastic Leukemia ◽  
Epigenetic Regulation ◽  
Lymphoblastic Leukemia ◽  
Genetic Alterations ◽  
Aberrant Methylation ◽  
Disease Phenotype ◽  
Genome Wide ◽  
Epigenetic Analysis

Abstract Abstract 537 Acute lymphoblastic leukemia (ALL), the commonest childhood malignancy, is characterized by recurring gross and submicroscopic structural genetic alterations that contribute to leukemogenesis. Disordered epigenetic regulation is a hallmark of many tumors, and while analysis of DNA methylation of limited numbers of genes or ALL samples suggests epigenetic alterations may also be important, a large-scale integrative genome-wide analysis evaluating DNA methylation in ALL has not been performed. Here, we report an integrated epigenomic, transcriptional and genetic analysis of 167 childhood ALL cases, comprising B-progenitor ALL with hyperdiploidy (N=26), ETV6-RUNX1 (N=27), TCF3-PBX1 (N=9), BCR-ABL1 (N=19), rearrangement of MLL (MLLr) (N=20), rearrangement of CRLF2 (N=11, CRLF2r), deletion of ERG (N=11), miscellaneous or normal karyotype (N=14), and T-lineage ALL (N=30), including 4 MLLr cases and 8 cases with early T-cell precursor immunophenotype. Genome-wide profiling of structural DNA alterations was performed for all cases using Affymetrix 500K and SNP 6.0 arrays. Affymetrix U133A gene expression profiling data was available for 154 cases. Genome-wide methylation profiling was performed using the HELP microarray assay, which measures methylation at approximately 50,000 CpGs distributed among 22,722 Refseq promoters. Methylation data was compared to that of normal pro-B (CD34+CD19+sIg-), pre-B (CD34-CD19+sIg-) and mature B (CD34-CD19+sIg+) cells FACS-sorted from bone marrow of 6 healthy individuals. Unsupervised hierarchical clustering of the top 4043 most variable methylation probesets identified 9 B-ALL clusters with significant correlation to specific genetic lesions including ETV6-RUNX1, MLLr, BCR-ABL1, CRLF2r, TCF3-PBX1 and ERG deletion. T-ALLs and hyperdiploid B-ALLs also defined specific DNA methylation clusters. Supervised analysis including limma and ANOVA identified distinct DNA methylation signatures for each subtype. Notably, the strength of these signatures was subtype dependent, with more differentially methylated genes observed in ALL cases with genetic alterations targeting transcriptional regulators (e.g. ETV6-RUNX1 and MLLr) and fewer genes in cases with alterations deregulating cytokine receptor signaling (e.g. CRLF2r). Aberrant DNA methylation affected specific and distinct biological processes in the various leukemia subtypes implicating epigenetic regulation of these pathways in the pathogenesis of these different forms of ALL (e.g. TGFB and TNF in ERG deleted leukemias; telomere and centriole regulation in BCR-ABL1 ALL). Aberrantly methylated genes were also enriched for binding sites of known or suspected oncogenic transcription factors that might represent cooperative influences in establishing the phenotype of the various B-ALL subtypes. Most importantly, an integrated analysis of methylation and gene expression of these ALL subtypes demonstrated striking inversely correlated expression of the corresponding gene transcripts. The methylation signatures of each subtype exhibited only partial overlap with those of normal B cells, indicating that the signatures do not simply reflect stage of lymphoid maturation. In a separate approach, we discovered that 81 genes showed consistent aberrant methylation across all ALL subtypes, including the tumor suppressor PDZD2, HOXA5, HOXA6 and MSH2. Inverse correlation with expression was confirmed in 66% of these genes. These data suggest the existence of a common epigenetic pathway underlying the malignant transformation of lymphoid precursor cells. Integrative genetic and epigenetic analysis revealed hypermethylation of genes on trisomic chromosomes that do not show increased expression, suggesting that epigenetic silencing may control genes within amplified regions and explain why only selected genes are overexpressed. Finally, analysis of individual genes targeted by recurring copy number alterations in ALL revealed a subset of genes also targeted by abnormal methylation, with corresponding changes in gene expression (e.g. ERG, GAB1), suggesting that such genes are inactivated far more frequently than suggested by genetic analyses alone. Collectively, the data support a key role of epigenetic gene regulation in the pathogenesis of ALL, and point towards a scenario where genetic and epigenetic lesions cooperatively determine disease phenotype. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Experimental DNA Demethylation Associates with Changes in Growth and Gene Expression of Oak Tree Seedlings

2020 ◽  
Vol 10 (3) ◽  
pp. 1019-1028 ◽  
Author(s):  
Luke Browne ◽  
Alayna Mead ◽  
Courtney Horn ◽  
Kevin Chang ◽  
Zeynep A. Celikkol ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Phenotypic Variation ◽  
Foliar Application ◽  
Substantial Reduction ◽  
Dna Demethylation ◽  
Soil Microbiome ◽  
Relative Reduction ◽  
Tree Seedlings ◽  
Genome Wide

Epigenetic modifications such as DNA methylation, where methyl groups are added to cytosine base pairs, have the potential to impact phenotypic variation and gene expression, and could influence plant response to changing environments. One way to test this impact is through the application of chemical demethylation agents, such as 5-Azacytidine, which inhibit DNA methylation and lead to a partial reduction in DNA methylation across the genome. In this study, we treated 5-month-old seedlings of the tree, Quercus lobata, with foliar application of 5-Azacytidine to test whether a reduction in genome-wide methylation would cause differential gene expression and change phenotypic development. First, we demonstrate that demethylation treatment led to 3–6% absolute reductions and 6.7–43.2% relative reductions in genome-wide methylation across CG, CHG, and CHH sequence contexts, with CHH showing the strongest relative reduction. Seedlings treated with 5-Azacytidine showed a substantial reduction in new growth, which was less than half that of control seedlings. We tested whether this result could be due to impact of the treatment on the soil microbiome and found minimal differences in the soil microbiome between two groups, although with limited sample size. We found no significant differences in leaf fluctuating asymmetry (i.e., deviations from bilateral symmetry), which has been found in other studies. Nonetheless, treated seedlings showed differential expression of a total of 23 genes. Overall, this study provides initial evidence that DNA methylation is involved in gene expression and phenotypic variation in seedlings and suggests that removal of DNA methylation affects plant development.

scholarly journals Genome-Wide Mapping of Cytosine Methylation Revealed Dynamic DNA Methylation Patterns Associated with Sporophyte Development of Saccharina japonica

2021 ◽  
Vol 22 (18) ◽  
pp. 9877
Author(s):  
Xiaoqi Yang ◽  
Xiuliang Wang ◽  
Jianting Yao ◽  
Delin Duan
Keyword(s):  
Dna Methylation ◽  
Epigenetic Regulation ◽  
Cytosine Methylation ◽  
Saccharina Japonica ◽  
Transcript Abundance ◽  
Methylation Pattern ◽  
Brown Macroalgae ◽  
Global Methylation ◽  
Genome Wide ◽  
Sporophyte Development

Cytosine methylation plays vital roles in regulating gene expression and plant development. However, the function of DNA methylation in the development of macroalgae remains unclear. Through the genome-wide bisulfite sequencing of cytosine methylation in holdfast, stipe and blade, we obtained the complete 5-mC methylation landscape of Saccharina japonica sporophyte. Our results revealed that the total DNA methylation level of sporophyte was less than 0.9%, and the content of CHH contexts was dominant. Moreover, the distribution of CHH methylation within the genes exhibited exon-enriched characteristics. Profiling of DNA methylation in three parts revealed the diverse methylation pattern of sporophyte development. These pivotal DMRs were involved in cell motility, cell cycle and cell wall/membrane biogenesis. In comparison with stipe and blade, hypermethylation of mannuronate C5-epimerase in holdfast decreased the transcript abundance, which affected the synthesis of alginate, the key component of cell walls. Additionally, 5-mC modification participated in the regulation of blade and holdfast development by the glutamate content respectively via glutamine synthetase and amidophosphoribosyl transferase, which may act as the epigenetic regulation signal. Overall, our study revealed the global methylation characteristics of the well-defined holdfast, stipe and blade, and provided evidence for epigenetic regulation of sporophyte development in brown macroalgae.

scholarly journals Genome-Wide DNA Methylation and Hydroxymethylation Changes Revealed Epigenetic Regulation of Neuromodulation and Myelination in Yak Hypothalamus

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhixin Chai ◽  
Zhijuan Wu ◽  
Qiumei Ji ◽  
Jikun Wang ◽  
Jiabo Wang ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Epigenetic Regulation ◽  
Bisulfite Sequencing ◽  
Brain Regions ◽  
Cattle Genome ◽  
Biological Functions ◽  
Reduced Representation ◽  
Genome Wide ◽  
Reduced Representation Bisulfite Sequencing ◽  
The Brain

Both 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) are important epigenetic modifications in neurodevelopment. However, there is little research examining the genome-wide patterns of 5mC and 5hmC in brain regions of animals under natural high-altitude conditions. We used oxidative reduced representation bisulfite sequencing (oxRRBS) to determine the 5mC and 5hmC sites in the brain, brainstem, cerebellum, and hypothalamus of yak and cattle. We reported the first map of genome-wide DNA methylation and hydroxymethylation in the brain, brainstem, cerebellum, and hypothalamus of yak (living at high altitudes) and cattle. Overall, we found striking differences in 5mC and 5hmC between the hypothalamus and other brain regions in both yak and cattle. Genome-wide profiling revealed that 5mC level decreased and 5hmC level increased in the hypothalamus than in other regions. Furthermore, we identified differentially methylated regions (DMRs) and differentially hydroxymethylated regions (DhMRs), most of which overlapped with each other. Interestingly, transcriptome results for these brain regions also showed distinctive gene levels in the hypothalamus. Finally, differentially expressed genes (DEGs) regulated by DMRs and DhMRs may play important roles in neuromodulation and myelination. Overall, our results suggested that mediation of 5mC and 5hmC on epigenetic regulation may broadly impact the development of hypothalamus and its biological functions.

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