scholarly journals FASTmC: a suite of predictive models for non-reference-based estimations of DNA methylation

2015 ◽  
Author(s):  
Adam J Bewick ◽  
Brigitte T Hofmeister ◽  
Kevin J Lee ◽  
Xiaoyu Zhang ◽  
Dave W Hall ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Predictive Models ◽  
Time Course ◽  
Bisulfite Sequencing ◽  
Reference Genome ◽  
Cost Effective ◽  
Genome Bisulfite Sequencing ◽  
Context Specific ◽  
Diversity Studies ◽  
Reference Cost

We describe a suite of predictive models, coined FASTmC, for non-reference, cost-effective exploration and comparative analysis of context-specific DNA methylation levels. Accurate estimations of true DNA methylation levels can be obtained from as few as several thousand short-reads generated from whole genome bisulfite sequencing. These models make high-resolution time course or developmental, and large diversity studies practical regardless of species, genome size and availability of a reference genome.

scholarly journals Whole-Genome Bisulfite Sequencing Reveals a Role for DNA Methylation in Variants from Callus Culture of Pineapple (Ananas comosus L.)

Genes ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 877 ◽  
Author(s):  
Wenqiu Lin ◽  
Xi’ou Xiao ◽  
Hongna Zhang ◽  
Yunhe Li ◽  
Shenghui Liu ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Callus Culture ◽  
Bisulfite Sequencing ◽  
Ananas Comosus ◽  
Whole Genome ◽  
Phenotypic Differences ◽  
Whole Genome Bisulfite Sequencing ◽  
Somaclonal Variations ◽  
Genome Bisulfite Sequencing ◽  
Context Specific

DNA methylation changes can occur in some loci during callus culture, resulting in somaclonal variations (SVs). In the present study, we applied whole genome bisulfite sequencing to analyze context-specific DNA methylation changes in the pineapple genome between the cutting seedings and 5 SV plants. In general, SV plants exhibited methylation patterns analogous to those of cutting seedlings (CK). A total of 27.98% of the genomic cytosines of CK were methylcytosines, which was higher than that of 5 SV plants. Moreover, mCG and mCHG was hypermethylated, whereas mCHH was hypomethylated among the 5 SV plants genomic when compared with the CK. Most of the variation of DNA methylation was distributed in gene bodies, thus suggesting that phenotypic differences are probably perturbed by genes methylated from callus culture. In addition, the methylated genes were highly enriched for the Gene Ontology (GO) categories of binding and catalytic activity, cell part and organelle, cellular process, abiotic stimulus, and DNA modification. These results suggest that methylation mediates these pathways in the callus culture of pineapple. The results also suggested that the callus culture induced DNA methylation may result in the SV.

scholarly journals Benchmarking DNA Methylation Assays for Marine Invertebrates

2020 ◽  
Author(s):  
Groves Dixon ◽  
Mikhail Matz
Keyword(s):  
Dna Methylation ◽  
Bisulfite Sequencing ◽  
Restriction Site ◽  
Marine Invertebrates ◽  
Cost Effective ◽  
Whole Genome ◽  
Ecological Research ◽  
Chromatin Modifications ◽  
Whole Genome Bisulfite Sequencing ◽  
Genome Bisulfite Sequencing

AbstractInterrogation of chromatin modifications, such as DNA methylation, has potential to improve forecasting and conservation of marine ecosystems. The standard method for assaying DNA methylation (Whole Genome Bisulfite Sequencing), however, is too costly to apply at the scales required for ecological research. Here we evaluate different methods for measuring DNA methylation for ecological epigenetics. We compare Whole Genome Bisulfite Sequencing (WGBS) with Methylated CpG Binding Domain Sequencing (MBD-seq), and a modified version of MethylRAD we term methylation-dependent Restriction site-Associated DNA sequencing (mdRAD). We evaluate these three assays in measuring variation in methylation across the genome, between genotypes, and between polyp types in the reef-building coral Acropora millepora. We find that all three assays measure absolute methylation levels similarly, with tight correlations for methylation of gene bodies (gbM), as well as exons and 1Kb windows. Correlations for differential gbM between genotypes were weaker, but still concurrent across assays. We detected little to no reproducible differences in gbM between polyp types. We conclude that MBD-seq and mdRAD are reliable cost-effective alternatives to WGBS. Moreover, the considerably lower sequencing effort required for mdRAD to produce comparable methylation estimates makes it particularly useful for ecological epigenetics.

scholarly journals Low-pass whole genome bisulfite sequencing of neonatal dried blood spots identifies a role for RUNX1 in Down syndrome DNA methylation profiles

2020 ◽  
Author(s):  
Benjamin I Laufer ◽  
Hyeyeon Hwang ◽  
Julia M Jianu ◽  
Charles E Mordaunt ◽  
Ian F Korf ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Down Syndrome ◽  
Early Life ◽  
Trisomy 21 ◽  
Bisulfite Sequencing ◽  
Dried Blood Spots ◽  
Whole Genome ◽  
Genome Wide ◽  
Low Pass ◽  
Genome Bisulfite Sequencing

Abstract Neonatal dried blood spots (NDBS) are a widely banked sample source that enables retrospective investigation into early life molecular events. Here, we performed low-pass whole genome bisulfite sequencing (WGBS) of 86 NDBS DNA to examine early life Down syndrome (DS) DNA methylation profiles. DS represents an example of genetics shaping epigenetics, as multiple array-based studies have demonstrated that trisomy 21 is characterized by genome-wide alterations to DNA methylation. By assaying over 24 million CpG sites, thousands of genome-wide significant (q < 0.05) differentially methylated regions (DMRs) that distinguished DS from typical development and idiopathic developmental delay were identified. Machine learning feature selection refined these DMRs to 22 loci. The DS DMRs mapped to genes involved in neurodevelopment, metabolism, and transcriptional regulation. Based on comparisons with previous DS methylation studies and reference epigenomes, the hypermethylated DS DMRs were significantly (q < 0.05) enriched across tissues while the hypomethylated DS DMRs were significantly (q < 0.05) enriched for blood-specific chromatin states. A ~28 kb block of hypermethylation was observed on chromosome 21 in the RUNX1 locus, which encodes a hematopoietic transcription factor whose binding motif was the most significantly enriched (q < 0.05) overall and specifically within the hypomethylated DMRs. Finally, we also identified DMRs that distinguished DS NDBS based on the presence or absence of congenital heart disease (CHD). Together, these results not only demonstrate the utility of low-pass WGBS on NDBS samples for epigenome-wide association studies, but also provide new insights into the early life mechanisms of epigenomic dysregulation resulting from trisomy 21.

164 Genome-wide DNA Methylation Profiling in in Utero Heat-stressed Pigs as Measured by Whole-genome Bisulfite Sequencing

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 87-88
Author(s):  
Luiz F Brito ◽  
Jacob M Maskal ◽  
Shi-Yi Chen ◽  
Hinayah R Oliveira ◽  
Jason R Graham ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Heat Stress ◽  
Cellular Response ◽  
Bisulfite Sequencing ◽  
Cholesterol Biosynthesis ◽  
In Utero ◽  
Whole Genome ◽  
Whole Genome Bisulfite Sequencing ◽  
Differentially Methylated Genes ◽  
Genome Bisulfite Sequencing

Abstract In utero heat stress (IUHS) has several postnatal consequences in pigs that compromise health, increase stress response, and reduce performance. These phenotypes may be caused by epigenetic modifications such as DNA methylation, which are heritable molecular modifications that impact gene expression and phenotypic outcomes without changing the DNA sequence. Therefore, we aimed to compare the DNA methylation profiles between in-utero thermoneutral (IUTN) and IUHS pigs to identify differentially methylated regions. Twenty-four pregnant gilts were evenly assigned to either a thermoneutral (17.5 ± 2.1°C) or heat stress (cycling 26 to 36°C) chamber from d 0 to 59 of gestation, followed by thermoneutral conditions (20.9 ± 2.3°C) for the rest of gestation and until the piglets were weaned. At 105 d of age, 10 IUTN and 10 IUHS piglets were euthanized and Longissimus dorsi muscle samples were collected and used to perform whole-genome bisulfite sequencing (WGBS). Purified genomic DNA was fragmented and bisulfite conversion was performed. Illumina platforms were used to sequence WGBS libraries. All pigs had similar proportions of methylation at CpG sites. Two-hundred-sixty-eight genomic regions were differentially methylated between IUTN and IUHS pigs. These identified regions are located across all pig chromosomes and ranged from 2 (SSC18) to 40 (SSC10). Eighty-five unique differentially-methylated genes were identified. These genes have been reported to be involved in key biological processes such as transcriptional repressor activity and tRNA processing (e.g., SKOR2,TRMT6, TSEN2), cellular response to heat stress (e.g.,CCAR2), placental vascularization (e.g.,FZD5), central nervous system (e.g.,VEPH1), cholesterol biosynthesis (e.g., CYB5R1), insulin receptor substrate (e.g.,IRS2), synaptic transmission (e.g.,RIMBP2), neurotrophic factor receptor activity (e.g.,LIFR), immune response (e.g., CD84), DNA repair (e.g., CHD1L), and cell proliferation and endocrine signaling (e.g., SSTR1, CYB5R1). These findings contribute to a better understanding of the epigenomic mechanisms underlying postnatal consequences of IUHS in pigs.

scholarly journals Efficient and accurate determination of genome-wide DNA methylation patterns in Arabidopsis thaliana with enzymatic methyl sequencing

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Suhua Feng ◽  
Zhenhui Zhong ◽  
Ming Wang ◽  
Steven E. Jacobsen
Keyword(s):  
Dna Methylation ◽  
Bisulfite Sequencing ◽  
Accurate Determination ◽  
Gc Content ◽  
Epigenetic Mark ◽  
Whole Genome ◽  
Whole Genome Bisulfite Sequencing ◽  
Genome Wide ◽  
A Genome ◽  
Genome Bisulfite Sequencing

Abstract Background 5′ methylation of cytosines in DNA molecules is an important epigenetic mark in eukaryotes. Bisulfite sequencing is the gold standard of DNA methylation detection, and whole-genome bisulfite sequencing (WGBS) has been widely used to detect methylation at single-nucleotide resolution on a genome-wide scale. However, sodium bisulfite is known to severely degrade DNA, which, in combination with biases introduced during PCR amplification, leads to unbalanced base representation in the final sequencing libraries. Enzymatic conversion of unmethylated cytosines to uracils can achieve the same end product for sequencing as does bisulfite treatment and does not affect the integrity of the DNA; enzymatic methylation sequencing may, thus, provide advantages over bisulfite sequencing. Results Using an enzymatic methyl-seq (EM-seq) technique to selectively deaminate unmethylated cytosines to uracils, we generated and sequenced libraries based on different amounts of Arabidopsis input DNA and different numbers of PCR cycles, and compared these data to results from traditional whole-genome bisulfite sequencing. We found that EM-seq libraries were more consistent between replicates and had higher mapping and lower duplication rates, lower background noise, higher average coverage, and higher coverage of total cytosines. Differential methylation region (DMR) analysis showed that WGBS tended to over-estimate methylation levels especially in CHG and CHH contexts, whereas EM-seq detected higher CG methylation levels in certain highly methylated areas. These phenomena can be mostly explained by a correlation of WGBS methylation estimation with GC content and methylated cytosine density. We used EM-seq to compare methylation between leaves and flowers, and found that CHG methylation level is greatly elevated in flowers, especially in pericentromeric regions. Conclusion We suggest that EM-seq is a more accurate and reliable approach than WGBS to detect methylation. Compared to WGBS, the results of EM-seq are less affected by differences in library preparation conditions or by the skewed base composition in the converted DNA. It may therefore be more desirable to use EM-seq in methylation studies.

scholarly journals How to Design a Whole-Genome Bisulfite Sequencing Experiment

Epigenomes ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 21 ◽  
Author(s):  
Claudius Grehl ◽  
Markus Kuhlmann ◽  
Claude Becker ◽  
Bruno Glaser ◽  
Ivo Grosse
Keyword(s):  
Dna Methylation ◽  
Bisulfite Sequencing ◽  
Alternative Methods ◽  
Transcriptional Gene Silencing ◽  
Whole Genome ◽  
Reduced Representation ◽  
Genome Region ◽  
Whole Genome Bisulfite Sequencing ◽  
Sequencing Experiment ◽  
Genome Bisulfite Sequencing

Aside from post-translational histone modifications and small RNA populations, the epigenome of an organism is defined by the level and spectrum of DNA methylation. Methyl groups can be covalently bound to the carbon-5 of cytosines or the carbon-6 of adenine bases. DNA methylation can be found in both prokaryotes and eukaryotes. In the latter, dynamic variation is shown across species, along development, and by cell type. DNA methylation usually leads to a lower binding affinity of DNA-interacting proteins and often results in a lower expression rate of the subsequent genome region, a process also referred to as transcriptional gene silencing. We give an overview of the current state of research facilitating the planning and implementation of whole-genome bisulfite-sequencing (WGBS) experiments. We refrain from discussing alternative methods for DNA methylation analysis, such as reduced representation bisulfite sequencing (rrBS) and methylated DNA immunoprecipitation sequencing (MeDIPSeq), which have value in specific experimental contexts but are generally disadvantageous compared to WGBS.

scholarly journals DNA methylation estimation using methylation-sensitive restriction enzyme bisulfite sequencing (MREBS)

2017 ◽  
Author(s):  
Giancarlo Bonora ◽  
Liudmilla Rubbi ◽  
Marco Morselli ◽  
Constantinos Chronis ◽  
Kathrin Plath ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Restriction Enzyme ◽  
Large Scale ◽  
Bisulfite Sequencing ◽  
Multiple Regression Model ◽  
Reduced Representation ◽  
A Genome ◽  
Genome Bisulfite Sequencing ◽  
Methylation Sensitive Restriction Enzyme ◽  
Wide Scale

ABSTRACTWhole-genome bisulfite sequencing (WGBS) and reduced representation bisulfite sequencing (RRBS) are widely used for measuring DNA methylation levels on a genome-wide scale(1). Both methods have limitations: WGBS is expensive and prohibitive for most large-scale projects; RRBS only interrogates 6-12% of the CpGs in the human genome(16,19). Here, we introduce methylation-sensitive restriction enzyme bisulfite sequencing (MREBS) which has the reduced sequencing requirements of RRBS, but significantly expands the coverage of CpG sites in the genome. We built a multiple regression model that combines the two features of MREBS: the bisulfite conversion ratios of single cytosines (as in WGBS and RRBS) as well as the number of reads that cover each locus (as in MRE-seq(12)). This combined approach allowed us to estimate differential methylation across 60% of the genome using read count data alone, and where counts were sufficiently high in both samples (about 1.5% of the genome), our estimates were significantly improved by the single CpG conversion information. We show that differential DNA methylation values based on MREBS data correlate well with those based on WGBS and RRBS. This newly developed technique combines the sequencing cost of RRBS and DNA methylation estimates on a portion of the genome similar to WGBS, making it ideal for large-scale projects of mammalian genomes.

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