Bisulfite Sequencing Research Articles

Decoding the Root Lignification Mechanism of Angelica sinensis through Genome-wide Methylation Analysis.

Angelica sinensis is a traditional Chinese herbal medicine with significant economic and medicinal value. However, early bolting and flowering can occur during the second year of the vegetative growth period, rendering the roots unviable for medicinal use and resulting in substantial economic losses. Consequently, the growing interest in studying the molecular mechanisms underlying early bolting or increased root lignification in A. sinensis. Here, we conducted whole-genome bisulfite sequencing and observed an increase in whole-genome DNA methylation levels on chromosomes after bolting in A. sinensis. Comparative analysis revealed methylation patterns in the upstream, gene body, and downstream regions in the context of CG, CHG, and CHH, suggesting a possible association between CHH-type methylation of promoters and phenylpropanoid biosynthesis. Furthermore, joint analysis of transcriptomic and methylomics data revealed a positive correlation between DNA methylation and gene expression. We identified the hyperDMR gene in the CHH background within the promoter region; this gene is also a key gene (AsCOMT1), exhibiting dual catalytic activity and facilitating the synthesis of both ferulic acid and lignin. Enzyme kinetic analysis demonstrated that AsCOMT1 preferentially catalyzes the synthesis of lignin monomer precursors. These findings highlight the important regulatory role of DNA methylation in bolting and the synthesis of secondary metabolites in A. sinensis, providing valuable insights into the underlying molecular mechanisms. Therefore, as DNA methylation plays an important regulatory role in A. sinensis bolting and secondary metabolite synthesis, it has potential significance in the analysis of the underlying molecular mechanism.

204 Changes in DNA methylation 5 days after exposure to acute heat stress in beef cattle skeletal muscle

Abstract The objective of this study was to investigate the effects of acute heat stress on the skeletal muscle epigenome using reduced representation bisulfite sequencing (RRBS). March-born crossbred (5/8 Red Angus, 3/8 Simmental) steers (n = 14; average body weight = 308.7 kg) were exposed to heat stress (HS) conditions of 35°C + 35% relative humidity (Temperature Humidity Index = 81) for 12h/d for 2 d (48 h). Longissimus dorsi samples were collected via biopsy and flash-frozen in liquid nitrogen immediately following the HS period at 48 h and from the contralateral longissimus dorsi 5 d later. DNA was isolated and underwent RRBS using 150 bp paired-end reads at an achieved average depth of 15.3 million reads/sample. Reads were trimmed and mapped to a bisulfite-converted bovine genome (ARSUCD1.2). Methylation calls were extracted and used to identify differentially methylated regions (DMRs) with methylkit in R comparing samples collected 5 d post-HS to those taken immediately post-48 h of HS. Differentially methylated regions (1,000 bp) had q < 0.05 and at least a 15% difference in methylation. There were 1,015 DMRs in genes. Hypomethylated DMRs 5 d post-HS included IGF1R, IGF2, IGF2BP1, IGFBP4, IGF2R, IKBKB, and IL34. Hypermethylated DMRs 5 d post-HS included FGF5, FGFR1, and FGFR3. There were 81 DMRs in putative promoter regions (2000 bp 5’ of a gene). MYLK2, SIGIRR, and 25 other genes had hypomethylated promoter regions. Genes that contained DMRs were used as input for DAVID to explore KEGG pathways. Enriched pathways (P < 0.1) included multiple hormone pathways, MAPK, PI3K-Akt, HIF-1, and VEGF. Hypomethylation of IGF-related genes and hypermethylation of FGF-related genes suggests impaired growth capacity post-HS, as does the enrichment of MAPK and PI3K-Akt pathways. Hypomethylation of SIGIRR’s promoter region, IL34 and IKBKB, indicates enhanced anti-inflammatory activity given their known regulation of inflammatory cytokine production. This, coupled with enrichment of the HIF-1 and VEGF pathways, suggests regulatory dampening of HS-induced oxidative stress. These findings reveal key regulatory changes in muscle growth, inflammatory response, and oxidative stress activity for cattle recovering from acute HS. Previous cattle skeletal muscle RNA studies predicted that HS altered metabolism, inflammation, and oxidative stress pathways, similar to the methylation results of this study. Overall, evidence suggests growth dysregulation, which may help explain observed HS-induced poor growth due to HS, as well as subsequent anti-inflammatory activity during recovery from HS.

438 DNA methylation patterns and transcriptional regulation during pig fetal skeletal muscle development

Abstract Fetal development is controlled by a complex cascade of highly regulated and coordinated gene expression patterns. Epigenetic mechanisms have important roles in regulating development and differentiation. Among such mechanisms, DNA methylation exhibits context-specific associations with gene expression and has been shown to be highly dynamic during developmental processes. We performed whole-genome bisulfite sequencing (WGBS) to assess DNA methylation in pig longissimus dorsi muscle at 41- and 70-d gestation (dg), as well as RNA- and small RNA-sequencing to identify coordinated changes in methylation and expression between myogenic stages. We identified 45,739 differentially methylated regions (DMRs) between stages, and the majority (n = 34,232) were hypomethylated at 70 vs. 41 dg. Developmental DMRs exhibited feature-specific enrichment in gene regulatory regions, as well as in regions proximal to micro-RNAs (miRNAs) that have known roles in myogenesis. Integration of methylation and transcriptomic data revealed strong associations between differential gene methylation and transcript abundance. We surveyed myogenic regulatory factor (MRF) genes to determine if differential methylation was present in expected genomic regions. Within the MYF5 and MYF6 locus, MYF5 was significantly promoter-hypermethylated at 70 dg, whereas MYF6 was significantly hypomethylated upstream of its transcription start site. MYF5 is the earliest MRF to be expressed and primarily functions in myoblast proliferation and determination, while MYF6 functions in muscle cell differentiation. Thus, these patterns were consistent with expected downregulation of MYF5 and upregulation of MYF6 as muscle development progresses and demonstrate that differential methylation is evident at myogenic transcription factors. Differential miRNA methylation was significantly negatively correlated with abundance, and dynamic expression of assayed miRNAs persisted postnatally. Motif analysis revealed significant enrichment of myogenic regulatory factor motifs among hypomethylated regions, suggesting that DNA hypomethylation may function to increase accessibility of muscle-specific transcription factors. We also show that developmental DMRs are enriched for GWAS SNPs associated with muscle physiology and meat quality traits, demonstrating the potential for epigenetic processes to influence phenotypic diversity. Our results enhance understanding of DNA methylation dynamics in pig fetal skeletal muscle and reveal putative cis-regulatory elements governed by epigenetic processes during porcine myogenesis.

STUB1-mediated K63-linked ubiquitination of UHRF1 promotes the progression of cholangiocarcinoma by maintaining DNA hypermethylation of PLA2G2A

BackgroundCholangiocarcinoma (CCA) is a highly malignant tumor characterized by a lack of effective targeted therapeutic strategies. The protein UHRF1 plays a pivotal role in the preservation of DNA methylation and works synergistically with DNMT1. Posttranscriptional modifications (PTMs), such as ubiquitination, play indispensable roles in facilitating this process. Nevertheless, the specific PTMs that regulate UHRF1 in CCA remain unidentified.MethodsWe confirmed the interaction between STUB1 and UHRF1 through mass spectrometry analysis. Furthermore, we investigated the underlying mechanisms of the STUB1-UHRF1/DNMT1 axis via co-IP experiments, denaturing IP ubiquitination experiments, nuclear‒cytoplasmic separation and immunofluorescence experiments. The downstream PLA2G2A gene, regulated by the STUB1-UHRF1/DNMT1 axis, was identified via RNA-seq. The negative regulatory mechanism of PLA2G2A was explored via bisulfite sequencing PCR (BSP) experiments to assess changes in promoter methylation. The roles of PLA2G2A and STUB1 in the proliferation, invasion, and migration of CCA cells were assessed using the CCK-8 assay, colony formation assay, Transwell assay, wound healing assay and xenograft mouse model. We evaluated the effects of STUB1/UHRF1 on cholangiocarcinoma by utilizing a primary CCA mouse model.ResultsThis study revealed that STUB1 interacts with UHRF1, resulting in an increase in the K63-linked ubiquitination of UHRF1. Consequently, this facilitates the nuclear translocation of UHRF1 and enhances its binding affinity with DNMT1. The STUB1-UHRF1/DNMT1 axis led to increased DNA methylation of the PLA2G2A promoter, subsequently repressing its expression. Increased STUB1 expression in CCA was inversely correlated with tumor progression and overall survival. Conversely, PLA2G2A functions as a tumor suppressor in CCA by inhibiting cell proliferation, invasion and migration.ConclusionsThese findings suggest that the STUB1-mediated ubiquitination of UHRF1 plays a pivotal role in tumor progression by epigenetically silencing PLA2G2A, underscoring the potential of STUB1 as both a prognostic biomarker and therapeutic target for CCA.Graphical

Epigenetic silencing of ZIC4 unveils a potential tumor suppressor role in pediatric choroid plexus carcinoma

Zic family member ZIC4 is a transcription factor that has been shown to be silenced in several cancers. However, understanding the regulation and function of ZIC4 in pediatric choroid plexus tumors (CPTs) remained limited. This study employed data mining and bioinformatics analysis to investigate the DNA methylation status of ZIC4 in CPTs and its correlation with patient survival. Our results unveiled ZIC4 methylation as a segregating factor, dividing CPT cohorts into two clusters, with hyper-methylation linked to adverse prognosis. Hyper-methylation of ZIC4 was confirmed in a choroid plexus carcinoma-derived cell line (CCHE-45) by bisulfite sequencing. Furthermore, our study demonstrated that demethylating agent and a histone methyltransferase inhibitor could reverse ZIC4 silencing. RNA sequencing and proteomic analysis showed that ZIC4 over-expression influenced genes and proteins involved in immune response, antigen processing and presentation, endoplasmic reticulum stress, and metabolism. Functionally, re-expressing ZIC4 negatively impacted cell proliferation and migration. Ultimately, these findings underscore ZIC4 hyper-methylation as a prognostic marker in CPTs and shed light on potential mechanisms underlying its tumor suppressor role in CPC. This insight paves the way for novel therapeutic targets in treating aggressive CPTs.

Decreased plasma gelsolin fosters a fibrotic tumor microenvironment and promotes chemoradiotherapy resistance in esophageal squamous cell carcinoma

BackgroundStromal fibrosis is highly associated with therapeutic resistance and poor survival in esophageal squamous cell carcinoma (ESCC) patients. Low expression of plasma gelsolin (pGSN), a serum abundant protein, has been found to correlate with inflammation and fibrosis. Here, we evaluated pGSN expression in patients with different stages of cancer and therapeutic responses, and delineated the molecular mechanisms involved to gain insight into therapeutic strategies for ESCC.MethodsCirculating pGSN level in ESCC patients was determined by enzyme-linked immunosorbent assay analysis, and the tissue microarray of tumors was analyzed by immunohistochemistry staining. Cell-based studies were performed to investigate cancer behaviors and molecular mechanisms, and mouse models were used to examine the pGSN-induced tumor suppressive effects in vivo.ResultsCirculating pGSN expression is distinctively decreased during ESCC progression, and low pGSN expression correlates with poor therapeutic responses and poor survival. Methylation-specific PCR analysis confirmed that decreased pGSN expression is partly attributed to the hypermethylation of the GSN promoter, the gene encoding pGSN. Importantly, cell-based immunoprecipitation and protein stability assays demonstrated that pGSN competes with oncogenic tenascin-C (TNC) for the binding and degradation of integrin αvβ3, revealing that decreased pGSN expression leads to the promotion of oncogenic signaling transduction in cancer cells and fibroblasts. Furthermore, overexpression of pGSN caused the attenuation of TNC expression and inactivation of cancer-associated fibroblast (CAF), thereby leading to tumor growth inhibition in mice.ConclusionsOur results demonstrated that GSN methylation causes decreased secretion of pGSN, leading to integrin dysregulation, oncogenic TNC activation, and CAF formation. These findings highlight the role of pGSN in therapeutic resistance and the fibrotic tumor microenvironment of ESCC.

The molecular significance of BRCA1 promoter methylation in peripheral blood cells in women with breast cancer in West Algeria

IntroductionEpigenetic alterations, in particular DNA methylation, are the most important mechanism that silences tumor suppressor genes during carcinogenesis. Methylation of the BRCA1 promoter in peripheral blood is associated with an increased risk of breast cancer. In the present study, we aimed, for the first time in western Algeria, to investigate the role of BRCA1 CpG promoter methylation in peripheral blood cells (PBCs) among breast cancer patients, as a potential biomarker for detecting breast cancer risk at an early age.Material and methodsThe methylation profile of the BRCA1 gene promoter and its frequency in PBCs, derived from 39 breast cancer patients, was explored by methylation-specific PCR (MSPCR). The association between methylation profiles and clinicopathological features was evaluated with SPSS statistics software to estimate a convenient biomarker for early detection of breast cancer.ResultsMSPCR results demonstrated that the methylation frequency of the BRCA1 gene promoter detected in PBCs is significantly higher than in other populations. It was observed in 23 of 39 (58.97%) breast cancer patients.ConclusionsOur study showed that the methylation of the BRCA1 gene promoter detected in PBCs’ DNA could have potential utility in clinical diagnostics as a new biomarker for breast cancer risk in Algerian women and for early detection.

The NRF2-KEAP1 pathway and epigenetic control in colorectal cancer: A promising prognostic and predictive biomarker

In colorectal cancer (CRC), important genes in the NRF2/KEAP1 pathway may undergo methylation, yet the exact genes that control this pathway in CRC are not entirely understood. Targeting the NRF2/KEAP1 pathway could be a valuable therapeutic strategy for colorectal cancer. Our research examined the methylation and expression of the KEAP1 gene in precancerous lesions and colorectal cancer, as well as investigated this pathway in the HT-29 cell line for potential CRC treatment. In this study, 208 frozen colorectal tissue samples were analysed, including 34 tumours, 60 precancerous lesions with adjacent normal tissues, and 20 normal tissue samples. The methylation-specific PCR and quantitative PCR were used to examine KEAP1 gene promoter methylation, and NRF2 and KEAP1 gene expressions, respectively. Furthermore, the HT 29 cell line was treated with 5-Azacytidine, followed by quantitative real-time PCR to evaluate post-demethylation KEAP1 and NRF2 mRNA expression. Unlike NRF2, our research revealed a notable reduction in KEAP1 gene expression in CRC tissues compared to adjacent normal tissues (p=0.02). Intriguingly, treating the HT-29 cell line with 5-Azacytidine led to a significant increase in KEAP1 gene expression compared to untreated cells (P=0.03), with no significant alteration observed in NRF2 gene expression. Examination of CpG islands within the KEAP1 gene promoter indicated extensive hypermethylation in 58.8% of tumour tissues compared to adjacent normal samples. These findings indicate that decreased KEAP1 gene expression resulting from promoter hypermethylation could interfere with the NRF2/KEAP1 pathway, a crucial mechanism in colorectal carcinogenesis. The study proposes that KEAP1 may play a significant role in the progression of CRC and could potentially serve as a biomarker for diagnosing and monitoring therapy in CRC

Maternal folic acid over-supplementation impairs cardiac function in mice offspring by inhibiting SOD1 expression.

Folic acid (FA) supplementation during pregnancy aims to protect foetal development. However, maternal over-supplementation of FA has been demonstrated to cause metabolic dysfunction and increase the risk of autism, retinoblastoma, and respiratory illness in the offspring. Moreover, FA supplementation reduces the risk of congenital heart disease. However, little is known about its possible adverse effects on cardiac health resulting from maternal over-supplementation. In this study, we assessed the detrimental effects of maternal FA over-supplementation on the cardiac health of the offspring. Eight-week-old C57BL/6J pregnant mice were randomly divided into control and over-supplemented groups. The offspring cardiac function was assessed using echocardiography. Cardiac fibrosis was assessed in the left ventricular myocardium by histological analysis. Proteomic, protein, RNA, and DNA methylation analyses were performed by liquid chromatography-tandem mass spectrometry, western blotting, real-time quantitative PCR, and bisulfite sequencing, respectively. We found that maternal periconceptional FA over-supplementation impaired cardiac function with the decreased left ventricular ejection fraction in the offspring. Biochemical indices and tissue staining further confirmed impaired cardiac function in offspring caused by maternal FA over-supplementation. The combined proteomic, RNA expression, and DNA methylation analyses suggested that key genes involved in cardiac function were inhibited at the transcriptional level possibly due to increased DNA methylation. Among these, superoxide dismutase 1 was downregulated, and reactive oxygen species (ROS) levels increased in the mouse heart. Inhibition of ROS generation using the antioxidant N-acetylcysteine rescued the impaired cardiac function resulting from maternal FA over-supplementation. Our study revealed that over-supplementation with FA during mouse pregnancy is detrimental to cardiac function with the decreased left ventricular ejection fraction in the offspring and provides insights into the mechanisms underlying the association between maternal FA status and health outcomes in the offspring.

The group of hypermethylated long noncoding RNA genes is associated with different types of metastasis in ovarian cancer

Background: Ovarian tumors are characterized by asymptomatic progression until their late stages, when at the time of diagnosis the patient already has extensive metastatic disease. In addition to lymphogenous and hematogenous metastasis in ovarian cancer, there are peritoneal dissemination and metastasis to the greater omentum with ascites; moreover, peritoneal carcinomatosis is the predominant route of metastasizing of ovarian cancer. Epigenetic factors, such as gene methylation, regulatory microRNAs and long non-coding RNAs (lncRNAs), contribute to progression of this cancer. Our previous bioinformatic and experimental studies have identified 13 genes of lncRNAs (GAS5, HOTAIR, LINC00472, LINC00886, MAFG-DT, PLUT/PDX1-AS1, SNHG1, SNHG6, SNHG12, SNHG17, TINCR, TP53TG1, TUG1) hypermethylated in the ovarian neoplasms. Aim: To evaluate the clinical significance of methylation levels of 13 lncRNA genes (GAS5, HOTAIR, LINC00472, LINC00886, MAFG-DT, PLUT/PDX1-AS1, SNHG1, SNHG6, SNHG12, SNHG17, TINCR, TP53TG1, TUG1) associated with various types of ovarian cancer metastasis, including lymphogenous, peritoneal, omental, and distant metastases. Methods: The methylation levels of lncRNA genes GAS5, HOTAIR, LINC00472, LINC00886, MAFG-DT, PLUT/PDX1-AS1, SNHG1, SNHG6, SNHG12, SNHG17, TINCR, TP53TG1, TUG1 were analyzed by quantitative real-time methylation-specific polymerase chain reaction. We tested 122 duplicate samples of ovarian neoplasms, including 104 malignancies and 18 borderline tumors, as well as 45 peritoneal macro metastases, collected in the N.N. Blokhin National Medical Research Center of Oncology in 2020 to 2023. The study included 21 samples of primary tumor from patients with lymphogenous metastases, 45 samples from patients with peritoneal dissemination, 61 from those with omental metastases, 49 from patients with ascites, and 9 with distant metastases. Results: The tumor samples from the patients with lymphatic nodes metastases showed a significant increase in the methylation level of two lncRNA genes: SNHG6 (p = 0.044) and SNHG12 (p = 0.006). Peritoneal dissemination was associated with hypermethylation of four lncRNA genes: GAS5, HOTAIR, LINC00472 (p 0.05), and most significantly TINCR (p = 0.001). GAS5, HOTAIR, LINC00886 (p 0.05) and most significantly LINC00472 (p 0.001) hypermethylation was typical for omental metastasis, and that of LINC00472 and LINC00886, with ascites (p 0.05). Peritoneal macroscopic metastases demonstrated increased methylation of MAFG-DT (p 0.001) and TP53TG1 (p 0.001) and desmethylation of LINC00886 (p = 0.003) and SNHG12 (p = 0.002), compared to their primary tumors. Conclusion: We performed the analysis of clinical significance of 13 hypermethylated lncRNA genes in ovarian cancer and were the first to show that 10 genes (GAS5, HOTAIR, LINC00472, LINC00886, MAFG-DT, SNHG6, SNHG12, TINCR, TP53TG1, TUG1) were associated with various types of ovarian tumor metastasis. Also, we were able to determine certain panels of lncRNA, which, if demonstrate abnormal methylation, were specific for lymphogenous and peritoneal metastasis of ovarian tumors.

Genome-wide analysis of DNA methylation and transcriptional changes associated with overwintering memory in Brassica rapa L. grown in the field

BackgroundWinter rapeseed, the sole overwintering oilseed crop in northern China, emphasizes winter resilience, yet epigenetic regulatory mechanisms governing overwintering memory remain poorly understood.ResultsIn this study, the root collar tissues from the robust cold-resistant variety Longyou-7 were sampled during the pre-winter period (S1), overwintering periods (S2–S5), and re-greening period (S6), to analyze overall genomic DNA methylation levels using high-performance liquid chromatography (HPLC). The result showed that DNA methylation level exceeded 80% in the S1 stage. Throughout the overwintering periods, methylation levels displayed a decreasing trend in S3, followed by an increase in S5, and a pronounced decrease in S6. Consequently, S1, S3, S5, and S6 periods were chosen for whole-genome bisulfite sequencing analyses to elucidate the overwintering memory mechanisms of Longyou-7. The result revealed that DNA methylation primarily occurs in the CG context in Longyou-7. However, methylation of mC sites is most prevalent in the CHH type, gradually decreasing during overwintering periods. Analysis of methylation patterns in specific genomic regions of Longyou-7 showed that the highest methylation levels in the intergenic region. Moreover, mC sites in repeats and transposon elements are distributed differently across the three contexts. Subsequently, differentially methylated regions and promoters of Longyou-7 were identified during various periods compared to the S1 stage, followed by joint analysis with transcriptome sequencing. Functional enrichment analysis highlighted the involvement of most overlapping genes in the MAPK signaling pathway, plant hormone signal transduction, and starch and sucrose metabolism pathways. Changes in candidate gene expression within these three pathways correlated closely with DNA methylation levels.ConclusionsOur findings underscored the critical role of DNA methylation in regulating the expression of overwintering memory genes in winter rapeseed. These results offer a comprehensive insights into the epigenetic regulatory mechanisms governing winter rapeseed's overwintering memory, while identified overwintering memory genes served as crucial genetic resources for multifaceted breeding of winter-resistant varieties.Graphical

Discovery and validation of colorectal cancer tissue-specific methylation markers: a dual-center retrospective cohort study

Background and purposeEarly detection, diagnosis, and treatment of colorectal cancer and its precancerous lesions can significantly improve patients’ survival rates. The purpose of this research is to identify methylation markers specific to colorectal cancer tissues and validate their diagnostic capability in colorectal cancer and precancerous changes by measuring the level of DNA methylation in stool samples.MethodWe analyzed samples from six cancer tissues and adjacent normal tissues and fecal samples from 758 participants, including 62 patients with interfering diseases. Bioinformatics databases were used to screen for candidate biomarkers for CRC, and quantitative methylation-specific PCR methods were applied for identification. The methylation levels of the candidate biomarkers in fecal and tissue samples were measured. Logistic regression and random forest models were built and validated using fecal sample data from one of the centers, and the independent or combined diagnostic value of the candidate biomarkers in fecal samples for CRC and precancerous lesions was analyzed. Finally, the diagnostic capability and stability of the model were validated at another medical center.ResultsThis study identified two colorectal cancer CpG sites with tissue specificity. These two biomarkers have certain diagnostic power when used individually, but their diagnostic value for colorectal cancer and colorectal adenoma is more significant when they are used in combination.ConclusionThe results indicate that a DNA methylation biomarker combined diagnostic model based on two CpG sites, cg13096260 and cg12587766, has the potential for screening and diagnosing precancerous lesions and colorectal cancer. Additionally, compared to traditional diagnostic models, machine learning algorithms perform better but may yield more false-positive results, necessitating further investigation.

D4Z4 Hypomethylation in Human Germ Cells.

Expression of the double homeobox 4 (DUX4) transcription factor is highly regulated in early embryogenesis and is subsequently epigenetically silenced. Ectopic expression of DUX4 due to hypomethylation of the D4Z4 repeat array on permissive chromosome 4q35 alleles is associated with facioscapulohumeral muscular dystrophy (FSHD). In peripheral blood samples from 188 healthy individuals, D4Z4 methylation was highly variable, ranging from 19% to 76%, and was not affected by age. In 48 FSHD2 patients, D4Z4 methylation varied from 3% to 30%. Given that DUX4 is one of the earliest transcribed genes after fertilization, the D4Z4 array is expected to be unmethylated in mature germ cells. Deep bisulfite sequencing of 188 mainly normozoospermic sperm samples revealed an average methylation of 2.5% (range 0.3-22%). Overall, the vast majority (78%) of individual sperm cells displayed no methylation at all. In contrast, only 19 (17.5%) of 109 individual germinal vesicle (GV) oocytes displayed D4Z4 methylation <2.5%. However, it is not unexpected that immature GV oocytes which are not usable for assisted reproduction are endowed with D4Z4 (up to 74%) hypermethylation and/or abnormal (PEG3 and GTL2) imprints. Although not significant, it is interesting to note that the pregnancy rate after assisted reproduction was higher for donors of sperm samples and oocytes with <2.5% methylation.

Early moderate prenatal alcohol exposure and maternal diet impact offspring DNA methylation across species.

Alcohol consumption in pregnancy can affect genome regulation in the developing offspring but results have been contradictory. We employed a physiologically relevant murine model of short-term moderate prenatal alcohol exposure (PAE) resembling common patterns of alcohol consumption in pregnancy in humans. Early moderate PAE was sufficient to affect site-specific DNA methylation in newborn pups without altering behavioural outcomes in adult littermates. Whole-genome bisulfite sequencing of neonatal brain and liver revealed stochastic influence on DNA methylation that was mostly tissue-specific, with some perturbations likely originating as early as gastrulation. DNA methylation differences were enriched in non-coding genomic regions with regulatory potential indicative of broad effects of alcohol on genome regulation. Replication studies in human cohorts with fetal alcohol spectrum disorder suggested some effects were metastable at genes linked to disease-relevant traits including facial morphology, intelligence, educational attainment, autism, and schizophrenia. In our murine model, a maternal diet high in folate and choline protected against some of the damaging effects of early moderate PAE on DNA methylation. Our studies demonstrate that early moderate exposure is sufficient to affect fetal genome regulation even in the absence of overt phenotypic changes and highlight a role for preventative maternal dietary interventions.

De novo Whole-Genome Assembly of the 10-Gigabase Fokienia Hodginsii Genome to Reveal Differential Epigenetic Events Between Callus and Xylem.

Fokienia hodginsii (F. hodginsii), belonging to the genus Fokienia of the Cupressaceae. F. hodginsii has significant application value due to its wood properties and great research value in evolutionary studies as a gymnosperm. However, the genome of F. hodginsii remains unknown due to the large size of gymnosperms genome. Pacific Bioscience sequencing, Hi-C mapping, whole-genome Bisulfite Sequencing (BS-Seq), long-read isoform sequencing (Iso-Seq), direct RNA sequencing (DRS), quantitative proteomics, and metabonomics analysis are employed to facilitate genome assembly, gene annotation, and investigation into epigenetic mechanisms. In this study, the 10G F. hodginsii genome is assembled into 11 chromosomes. Furthermore, 50521 protein-coding genes are annotated and determined that 65% of F. hodginsii genome comprises repetitive sequences. It is discovered that transposable element (TE)-including introns is associated with higher expression. The DNA methylome of F. hodginsii reveals that xylem has a higher DNA methylation level compared to callus. Moreover, DRS reveals the significant alterations in RNA full-length ratio, which potentially associated with poly(A) length (PAL) and alternative polyadenylation (APA). Finally, the morphology measurement and metabonomics analysis revealed the difference of 14 cultivars. In summary, the genomes and epigenetics datasets provide a molecular basis for callus formation in the gymnosperm family.

Personality vulnerability to depression, resilience, and depressive symptoms: epigenetic markers among perinatal women.

We examined differences in DNA methylation patterns in the NR3C1 and FKBP5 genes in relation to personality vulnerability to depression, resilience, and perinatal depressive symptoms, whilst also considering possible moderating effects of childhood traumatic events. N = 160 perinatal women were assessed at late pregnancy and 1 year postpartum for personality vulnerability to depression, resilience, depressive symptoms, and childhood traumatic events with self-reported questionnaires. NR3C1 and FKBP5 methylation markers were analyzed via sodium bisulfite sequencing. Associations of methylation markers with the above mentioned variables were tested using multivariable regressions. NR3C1 methylation at CpGs 1, 4 and average methylation sites were negatively associated with resilience; NR3C1 methylation at CpG 2 was positively associated with postpartum depressive symptoms; methylation at CpG 4 was positively associated with prenatal depressive symptoms. The interaction between current distress due to interpersonal traumatic events and NR3C1 CpG sites in relation to personality vulnerability was significant on CpG sites 3 and 4, whereas the interaction between current distress due to total traumatic events and NR3C1 in relation to personality vulnerability was significant on CpG site 2. FKBP5 showed no significant associations with the outcomes. This study identified associations between NR3C1 methylation and resilience as well as perinatal depressive symptoms. Interestingly, an interaction between early trauma and personality vulnerability was noted. Our findings on these specific DNA methylation markers may, if replicated and integrated into risk prediction models, contribute to early diagnosis of mothers at risk, targeted health promotion, and early interventions.

Reduced representation bisulfite sequencing (RRBS) analysis reveals variation in distribution and levels of DNA methylation in white birch (Betula papyrifera) exposed to nickel.

Research in understanding the role of genetics and epigenetics in plant adaptations to environmental stressors such as metals is still in its infancy. The objective of the present study is to assess the effect of nickel on DNA methylation level and distribution in white birch (Betula papyrifera Marshall) using reduced representation bisulfite sequencing (RRBS). The distribution of methylated C sites of each sample revealed that the level of methylation was much higher in CG context varying between 54% and 65%, followed by CHG (24%-31.5%), and then CHH with the methylation rate between 3.3% and 5.2%. The analysis of differentially methylated regions (DMR) revealed that nickel induced both hypermethylation and hypomethylation when compared to water. Detailed analysis showed for the first time that nickel induced a higher level of hypermethylation compared to controls, while potassium triggers a higher level of hypomethylation compared to nickel. Surprisingly, the analysis of the distribution of DMRs revealed that 38%-42% were located in gene bodies, 20%-24% in exon, 19%-20% in intron, 16%-17% in promoters, and 0.03%-0.04% in transcription start site. RRBS was successful in detecting and mapping DMR in plants exposed to nickel.

Zuogui Pills Improve the Learning and Memory Ability of Brain-Aging Mice through the Estrogen Receptor ERα Methylation Pathway.

Sex hormones are important factors in maintaining brain function and acting as brain protectors. Recent research suggests that neuronal damage in brain aging may be linked to the methylation of the estrogen receptor α (ERα). However, the mechanism of Zuogui Pills (ZGW) in brain-aging ERα DNA methylation and neuronal repair remains unknown. D-galactose-induced ovary removal mice were used as a model of aging. Changes in estrous cycle were detected in mice by vaginal cell smear. Animal behavior tests, including the Morris water maze (MWM) and new object recognition (NOR) test, were conducted. Hematoxylin-eosin (HE) and Nissl-staining were carried out to assess hippocampal neurogenesis. Enzyme-linked immunosorbent assay (ELISA) was performed for 5- methylcytosine methylation levels, and immunohistochemistry (IHC) and western blotting (WB) experiments were performed to assess ERα/DNA methyltransferase 1 (DNMT1) expression after ZGW treatment. Finally, bisulfite sequencing PCR (BSP) analysis was performed to identify methylated differentially expressed estrogen receptor 1 (ESR1) gene in D-gal-induced senescent neurons before and after ZGW treatment. We found that ERα methylation was involved in the delayed brain ageing process of ZGW. Mechanistically, ZGW can improve the learning and memory ability of brain-aging mice, reduce the expression of 5-methylcytosine (5-mc) in serum, increase the amount of ERα, inhibit the expression of DNMT1, and significantly reduce methylated expression of the ESRI gene. Our data suggested that ZGW slowed down D-gal-induced brain aging in mice, and these results showed that ZGW is beneficial for aging. It may be used for neuronal protection in aging.

Unravelling DNA methylation dynamics during developmental stages in Quercus ilex subsp. ballota [Desf.] Samp.

BackgroundDNA methylation is a critical factor influencing plant growth, adaptability, and phenotypic plasticity. While extensively studied in model and crop species, it remains relatively unexplored in holm oak and other non-domesticated forest trees. This study conducts a comprehensive in-silico mining of DNA methyltransferase and demethylase genes within the holm oak genome to enhance our understanding of this essential process in these understudied species. The expression levels of these genes in adult and seedling leaves, as well as embryos, were analysed using quantitative real-time PCR (qRT-PCR). Global DNA methylation patterns were assessed through methylation-sensitive amplified polymorphism (MSAP) techniques. Furthermore, specific methylated genomic sequences were identified via MSAP sequencing (MSAP-Seq).ResultA total of 13 DNA methyltransferase and three demethylase genes were revealed in the holm oak genome. Expression levels of these genes varied significantly between organs and developmental stages. MSAP analyses revealed a predominance of epigenetic over genetic variation among organs and developmental stages, with significantly higher global DNA methylation levels observed in adult leaves. Embryos exhibited frequent demethylation events, while de novo methylation was prevalent in seedling leaves. Approximately 35% of the genomic sequences identified by MSAP-Seq were methylated, predominantly affecting nuclear genes and intergenic regions, as opposed to repetitive sequences and chloroplast genes. Methylation was found to be more pronounced in the exonic regions of nuclear genes compared to their promoter and intronic regions. The methylated genes were predominantly associated with crucial biological processes such as photosynthesis, ATP synthesis-coupled electron transport, and defence response.ConclusionThis study opens a new research direction in analysing variability in holm oak by evaluating the epigenetic events and mechanisms based on DNA methylation. It sheds light on the enzymatic machinery governing DNA (de)methylation, and the changes in the expression levels of methylases and demethylases in different organs along the developmental stages. The expression level was correlated with the DNA methylation pattern observed, showing the prevalence of de novo methylation and demethylation events in seedlings and embryos, respectively. Several methylated genes involved in the regulation of transposable element silencing, lipid biosynthesis, growth and development, and response to biotic and abiotic stresses are highlighted. MSAP-seq integrated with whole genome bisulphite sequencing and advanced sequencing technologies, such as PacBio or Nanopore, will bring light on epigenetic mechanisms regulating the expression of specific genes and its correlation with the phenotypic variability and the differences in the response to environmental cues, especially those related to climate change.

DMAP2: A Pipeline for Analysis of Whole-Genome-Scale DNA Methylation Sequencing Data.

DNA methylation is well-established as a major epigenetic mechanism that can control gene expression and is involved in both normal development and disease. Analysis of high-throughput-sequencing-based DNA methylation data is a step toward understanding the relationship between disease and phenotype. Analysis of CpG methylation at single-base resolution is routinely done by bisulfite sequencing, in which methylated Cs remain as C while unmethylated Cs are converted to U, subsequently seen as T nucleotides. Sequence reads are aligned to the reference genome using mapping tools that accept the C-T ambiguity. Then, various statistical packages are used to identify differences in methylation between (groups of) samples. We have previously developed the Differential Methylation Analysis Pipeline (DMAP) as an efficient, fast, and flexible tool for this work, both for whole-genome bisulfite sequencing (WGBS) and reduced-representation bisulfite sequencing (RRBS). The protocol described here includes a series of scripts that simplify the use of DMAP tools and that can accommodate the wider range of input formats now in use to perform analysis of whole-genome-scale DNA methylation sequencing data in various biological and clinical contexts. © 2024 The Author(s). Current Protocols published by Wiley Periodicals LLC. Basic Protocol: DMAP2 workflow for whole-genome bisulfite sequencing (WGBS) and reduced-representation bisulfite sequencing (RRBS).