Gene bodies of vertebrates and flowering plants are occupied by histone variant H3.3 and DNA methylation. The origin and significance of these profiles remain largely unknown. The profiles of enrichments in DNA methylation and H3.3 over gene bodies are correlated and both depend similarly on gene transcription levels. This suggests a mechanistic link between H3.3 and gene body methylation. We engineered H3.3 knockdown in Arabidopsis and observed transcription reduction that predominantly affected genes responsive to environmental cues. When H3.3 levels were reduced, gene bodies showed a loss of DNA methylation correlated with transcription levels. To study the origin of changes in DNA methylation profiles when H3.3 levels are reduced, we examined genome wide distributions of several histone H3 marks, H2A.Z, linker histone H1 and nucleosome densities. We observed that in absence of H3.3, H1 distribution increased in gene bodies. This depends on levels of gene transcription. We propose that H3.3 prevents recruitment of H1, which in turn promotes chromatin folding and antagonizes access to DNA methyltransferases responsible for gene body methylation. Thus, gene body methylation is likely shaped by H3.3 dynamics in relation with transcriptional activity. Overall design: Examination of transcription in WT and H3.3 knock down samples by RNA-Seq
The histone H3 variant H3.3 regulates gene body DNA methylation in Arabidopsis thaliana.
Subject
View SamplesThe conserved multi-subunit Ccr4-Not complex regulates gene expression in diverse ways. In this work, we characterize the suppression of temperature sensitivity associated with a mutation in the gene encoding the scaffold subunit of the Ccr4-Not complex, NOT1, by the deletion of SPT3.
A SAGA-independent function of SPT3 mediates transcriptional deregulation in a mutant of the Ccr4-not complex in Saccharomyces cerevisiae.
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View SamplesTranscriptional analysis of multiple brain regions in Parkinson's disease supports the involvement of specific protein processing, energy metabolism, and signaling pathways, and suggests novel disease mechanisms.
Transcriptional analysis of multiple brain regions in Parkinson's disease supports the involvement of specific protein processing, energy metabolism, and signaling pathways, and suggests novel disease mechanisms.
Sex, Age, Disease, Disease stage
View SamplesPost mortem tissue was dissected from two groups of age and gender matched groups of Parkinson and Control subjects
Transcriptional analysis of multiple brain regions in Parkinson's disease supports the involvement of specific protein processing, energy metabolism, and signaling pathways, and suggests novel disease mechanisms.
Sex, Age, Disease, Disease stage
View SamplesPost mortem tissue was dissected from two groups of age and gender matched groups of Parkinson and Control subjects
Transcriptional analysis of multiple brain regions in Parkinson's disease supports the involvement of specific protein processing, energy metabolism, and signaling pathways, and suggests novel disease mechanisms.
Sex, Age, Disease, Disease stage
View SamplesPost mortem tissue was dissected from two groups of age and gender matched groups of Parkinson and Control subjects
Transcriptional analysis of multiple brain regions in Parkinson's disease supports the involvement of specific protein processing, energy metabolism, and signaling pathways, and suggests novel disease mechanisms.
Sex, Age, Disease, Disease stage
View SamplesObjectives: To identify similarities and differences in gene expression data in the MEK/ERK and PI3K pathways and to determine how histone modification affects these same pathways.
Regulation of gene expression by PI3K in mouse growth plate chondrocytes.
No sample metadata fields
View SamplesPositive selection occurs in the thymic cortex, but critical maturation events occur later in the medulla. We defined the precise stage at which T cells acquire competence to proliferate and emigrate. Transcriptome analysis of late gene changes suggested roles for NF-B and interferon signaling. Mice lacking the IKK kinase TAK1, showed normal positive selection, but a specific block in functional maturation. NF-B signaling provided protection from TNF, and was required for proliferation and emigration. Alternatively, the interferon signature was independent of NF-B, and IFNR deficient thymocytes showed reduced STAT1 levels and phenotypic abnormality, but were competent to proliferate. Thus, both NF-B and tonic IFN signals are involved in the final maturation of thymocytes into nave T cells.
Late stages of T cell maturation in the thymus involve NF-κB and tonic type I interferon signaling.
Specimen part
View SamplesThe function and retention/reprogramming of epigenetic marks during the germline-to-embryo transition is a key issue in developmental and cellular biology, with relevance to stem cell programming and trans-generational inheritance. In zebrafish, DNAme patterns are programmed in transcriptionally-quiescent early cleavage embryos; paternally-inherited patterns are maintained, whereas maternal patterns are reprogrammed to match the paternal pattern. Here we show that a 'placeholder' nucleosome, containing the histone H2A variant H2A.Z(FV) and H3K4me1, occupies virtually all regions lacking DNAme in both sperm and cleavage embryos – residing at promoters encoding housekeeping and early embryonic transcription factors. Upon genome-wide transcriptional onset, genes with the Placeholder become either active H3K4me3-marked or silent H3K4me3/K27me3-marked (bivalent). Importantly, functional perturbation causing Placeholder loss confers DNAme acquisition, whereas acquisition/expansion of Placeholder confers DNA hypomethylation and improper gene activation. Thus, during transcriptionally quiescent stages (gamete-zygote-cleavage), an H2A.Z(FV)/H3K4me1-containing Placeholder nucleosome deters DNAme, poising parental genes for either gene-specific activation or facultative repression. Overall design: Transcript abundance was analyzed for zebrafish sperm, and cleavage stage embryos that were either wild type or mutant for the anp32e gene.
Placeholder Nucleosomes Underlie Germline-to-Embryo DNA Methylation Reprogramming.
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View SamplesEpithelial cells provide an initial line of defense against damage and pathogens in barrier tissues such as the skin; however this balance is disrupted in obesity and metabolic disease. Skin gamma delta T cells recognize epithelial damage and release cytokines and growth factors that facilitate wound repair. To determine the impact of obesity and metabolic disease on skin gamma delta T cells, we isolated skin gamma delta T cells from 10-week old C57BLKS/J lean db/+ and obese db/db animals for further study. Due to a deficiency in the leptin receptor (db), homozygous db/db animals do not process satiety signals, continually eat and develop severe obesity and metabolic disease. Skin gamma delta T cells isolated from these animals were compared for changes in mRNA expression using microarray. We have determined that obesity and metabolic disease negatively impacts homeostasis and functionality of skin gamma delta T cells, rendering host defense mechanisms vulnerable to injury and infection.
Gammadelta T cells are reduced and rendered unresponsive by hyperglycemia and chronic TNFalpha in mouse models of obesity and metabolic disease.
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