Project description:We first demonstrate that non-genetically determined inter-individual differentially methylated regions (iiDMRs) can be temporally stable for at least two years. Then, we show that iiDMRS are associated with concomitant changes in chromatin state as measured by inter-individual differences in the levels of the histone variant H2A.Z. However, the correlation of promoter iiDMRs with gene expression is negligible and this correlation is not improved even by integrating H2A.Z information. We find that most promoter epialleles, whether genetically or non-genetically determined, are associated with low levels of transcriptional activity, depleted for house keeping genes, and either depleted for H3K4me3/enriched for H3K27me3, or lacking both these marks in human embryonic stem cells. These findings validate in an independent cohort. Interestingly, the key features of iiDMRs are reminiscent of those previously observed for promoters that undergo hyper-methylation in various cancers, in vitro cell culture, and human chronological ageing. H2A.z ChIP-seq, RNA-seq, and DNA methylation data (submitted separately) were collected for five normal individuals. T21/T22 and T31/T32 are monozygotic twins.
Project description:Inter-individual epigenetic variation, due to genetic, environmental or random influences, is observed in many eukaryotic species. In mammals, however, the molecular nature of epiallelic variation has been poorly defined, partly due to the restricted focus on DNA methylation. Here we report the first genome-scale investigation of mammalian epialleles that integrates genomic, methylomic, transcriptomic and histone state information.First, in a small sample set, we demonstrate that non-genetically determined inter-individual differentially methylated regions (iiDMRs) can be temporally stable over at least 2 years. Then, we show that iiDMRs are associated with changes in chromatin state as measured by inter-individual differences in histone variant H2A.Z levels. However, the correlation of promoter iiDMRs with gene expression is negligible and not improved by integrating H2A.Z information. We find that most promoter epialleles, whether genetically or non-genetically determined, are associated with low levels of transcriptional activity, depleted for housekeeping genes, and either depleted for H3K4me3/enriched for H3K27me3 or lacking both these marks in human embryonic stem cells. The preferential enrichment of iiDMRs at regions of relative transcriptional inactivity validates in a larger independent cohort, and is reminiscent of observations previously made for promoters that undergo hypermethylation in various cancers, in vitro cell culture and ageing.Our work identifies potential key features of epiallelic variation in humans, including temporal stability of non-genetically determined epialleles, and concomitant perturbations of chromatin state. Furthermore, our work suggests a novel mechanistic link among inter-individual epialleles observed in the context of normal variation, cancer and ageing.
Project description:We first demonstrate that non-genetically determined inter-individual differentially methylated regions (iiDMRs) can be temporally stable for at least two years. Then, we show that iiDMRS are associated with concomitant changes in chromatin state as measured by inter-individual differences in the levels of the histone variant H2A.Z. However, the correlation of promoter iiDMRs with gene expression is negligible and this correlation is not improved even by integrating H2A.Z information. We find that most promoter epialleles, whether genetically or non-genetically determined, are associated with low levels of transcriptional activity, depleted for house keeping genes, and either depleted for H3K4me3/enriched for H3K27me3, or lacking both these marks in human embryonic stem cells. These findings validate in an independent cohort. Interestingly, the key features of iiDMRs are reminiscent of those previously observed for promoters that undergo hyper-methylation in various cancers, in vitro cell culture, and human chronological ageing. DNA Methylation, H2A.z ChIP-seq, RNA-seq (submitted) separately were collected for five normal individuals (samples with "T" prefixes). T21/T22 and T31/T32 are monozygotic twins. Further DNA methylation data was collected from and additional two pairs of MZ twins with technical replication (samples with "C" prefixes - the three digits are pair number, individual number, and replicate number). Bisulphite converted DNA was hybridised to the Illumina Infinium 450k Human Methylation Beadchip
Project description:We first demonstrate that non-genetically determined inter-individual differentially methylated regions (iiDMRs) can be temporally stable for at least two years. Then, we show that iiDMRS are associated with concomitant changes in chromatin state as measured by inter-individual differences in the levels of the histone variant H2A.Z. However, the correlation of promoter iiDMRs with gene expression is negligible and this correlation is not improved even by integrating H2A.Z information. We find that most promoter epialleles, whether genetically or non-genetically determined, are associated with low levels of transcriptional activity, depleted for house keeping genes, and either depleted for H3K4me3/enriched for H3K27me3, or lacking both these marks in human embryonic stem cells. These findings validate in an independent cohort. Interestingly, the key features of iiDMRs are reminiscent of those previously observed for promoters that undergo hyper-methylation in various cancers, in vitro cell culture, and human chronological ageing.
Project description:We first demonstrate that non-genetically determined inter-individual differentially methylated regions (iiDMRs) can be temporally stable for at least two years. Then, we show that iiDMRS are associated with concomitant changes in chromatin state as measured by inter-individual differences in the levels of the histone variant H2A.Z. However, the correlation of promoter iiDMRs with gene expression is negligible and this correlation is not improved even by integrating H2A.Z information. We find that most promoter epialleles, whether genetically or non-genetically determined, are associated with low levels of transcriptional activity, depleted for house keeping genes, and either depleted for H3K4me3/enriched for H3K27me3, or lacking both these marks in human embryonic stem cells. These findings validate in an independent cohort. Interestingly, the key features of iiDMRs are reminiscent of those previously observed for promoters that undergo hyper-methylation in various cancers, in vitro cell culture, and human chronological ageing.
Project description:Urea can serve as nitrogen source for coral holobionts and plays a cruscial role in coral calcification, although the degradation of urea by coral symbionts is not fully understood. In this study, we investigated the urea utilized pathway and the responses of the Symbiodiniaceae family to urea under high temperature conditions. Genome screening revealed that all Symbiodiniaceae species contain the urease (URE) and DUR2 subunit of urea amidolyase (UAD) system. However, only three speciesCladocopium goreaui, Cladopium c92, and Symbiodinium pilosum possess a complete UAD system, including both DUR1 and DUR2. Phylogentic analyses revealed that the UAD system in Symbiodiniaceae clusters more closely with symbiotic bacteria, indicating that horizontal gene transfer of UAD system has occured in coral symbionts. Physiology analysis showed that the symbiodiniacean species Cladocopium goreaui, which containing both URE and UAD, grew better under urea than ammonium conditions, as indicated by higher maximum specific growth rates. Furthermore, most genes of Symbiodiniaceae involved in urea utilization appeared to be stable under various conditions such as heat stress (HS), low light density, and nitrogen deficiency, wheras in ammonium and nitrate transporters were significantly regulated. These relatively stable molecular regulatory properties support sustained urea absorption by Symbiodiniaceae, as evidenced by an increase in δ15N2-urea absorption and the decreases in δ5N-NO3-, and δ15N-NH4+ from cultural environment to Symbiodiniaceae under HS conditions. Token together, this study reveals two distinct urea utilization systems in coral ecosystem and highlights the importance of the urea cycle in coral symbionts when facing fluctuating nitrogen environment in future warming ocean.
Project description:Here we report a novel role for H2A.Z.2 (H2AFV) as a mediator of cell proliferation and sensitivity to targeted therapies in malignant melanoma. While both H2A.Z.1 and H2A.Z.2 are highly expressed in metastatic melanoma and correlate with decreased patient survival, only H2A.Z.2 deficiency results in impaired cellular proliferation of melanoma cells, which occurs via a G1/S arrest. Integrated gene expression and ChIP-seq analyses revealed that H2A.Z.2 positively regulates E2F target genes, and that such genes acquire a distinct H2A.Z occupancy signature over the promoter and gene body in metastatic melanoma cells. We further identified the BET family member BRD2 as an H2A.Z-interacting protein in melanoma cells, and demonstrate that H2A.Z.2 silencing cooperates with BET inhibition to induce cell death. Mononucleosomes from SK-mel147 (wt and stably expressing eGFP-H2A. eGFP-H2A.Z.1 and eGFP-H2A.Z.2) and melanocytes were isolated for ChIP with H2A.Z antibody or GFP trap beads (Chromotek).
Project description:Immunocytochemical studies revealed that dG9a moves into nucleus after cycle 8 and appears to regulate gene expression by di-methylating H3K9 from cycle 8 to cycle 11. To determine which genes are regulated by dG9a during cycles 8-11, we examined mRNA levels by performing RNA-sequence analysis using early embryos (0-2 h after egg laying) of dG9a null mutant and wild type as a control mRNA profiles of about 0-2h-old embryos of wild type (CantonS) and dG9a-depleted (dG9aRG5) strain
Project description:Background: Microorganisms are the major cause of food spoilage during storage, processing and distribution. Pseudomonas fluorescens is a typical spoilage bacterium that contributes to a large extent to the spoilage process of proteinaceous food. RpoS is considered an important global regulator involved in stress survival and virulence in many pathogens. Our previous work revealed that RpoS contributed to the spoilage activities of P. fluorescens by regulating resistance to different stress conditions, extracellular acylated homoserine lactone (AHL) levels, extracellular protease and total volatile basic nitrogen (TVB-N) production. However, RpoS-dependent genes in P. fluorescens remained undefined. Results: RNA-seq transcriptomics analysis combined with quantitative proteomics analysis basing on multiplexed isobaric tandem mass tag (TMT) labeling was performed for the P. fluorescens wild-type strain UK4 and its derivative carrying a rpoS mutation. A total of 375 differentially expressed genes (DEGs) and 212 differentially expressed proteins (DEPs) were identified in these two backgrounds. The DGEs were further verified by qRT-PCR tests, and the genes directly regulated by RpoS were confirmed by 5’-RACE-PCR sequencing. The combining transcriptome and proteome analysis revealed a role of this regulator in several cellular processes, including polysaccharide metabolism, intracellular secretion and extracellular structures, cell well biogenesis, stress responses, ammonia and biogenic amine production, which may contribute to biofilm formation, stress resistance and spoilage activities of P. fluorescens. Moreover, in this work we indeed observed that RpoS contributed to the production of the macrocolony biofilm’s matrix.