Intronic Non-CG DNA Hydroxymethylation and Alternative mRNA Splicing in Honey Bees
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ABSTRACT: Honey bee non-CG DNA hydroxymethylation is enriched in the introns, which supplements previous findings that honey bee CG DNA methylation is enriched in exons. Bisulfite sequencing combined with Pvu-Seq to distinguish 5-methylcytosine from 5-hydroxymethylcytosine and RNA-Seq
Project description:Plants of different ploidy levels are separated by a strong postzygotic hybridization barrier that is established in the endosperm. Deregulated parent-of-origin specific genes are causal for the response to interploidy hybridizations, revealing an epigenetic basis of this phenomenon. In this study we present evidence that paternal hypomethylation can bypass the interploidy hybridization barrier by alleviating the requirement of the epigenetic Polycomb Repressive Complex 2 (PRC2) in the endosperm. Bypass of the barrier is mediated by suppressed expression of imprinted genes. We show that hypomethylated pollen causes redistribution of CHG methylation to PRC2 target genes, revealing that different epigenetic modifications can functionally substitute for each other. Our work presents a method and the underlying mechanism for the generation of viable triploids, providing an impressive example for the potential of epigenome manipulations for plant breeding. Examination of DNA methylation in Arabidopsis endosperm, embryo, and pollen, and gene expression in seeds
Project description:This SuperSeries is composed of the following subset Series: GSE31344: smRNA sequencing of queen and virgin queen of two ants: Camponotus floridanus and Harpegnathos saltator GSE31346: Transcriptome sequencing of queen and virgin queen of two ants: Camponotus floridanus and Harpegnathos saltator GSE31576: Single base resolution methylome of two ants: Camponotus floridanus and Harpegnathos saltator Refer to individual Series
Project description:Methylation of chromosomal DNA in animals and plants is a fundamental mechanism of epigenetic regulation, and the maize genome, with its diverse complement of transposons and repeats, is a paradigm for transgenerational mechanisms such as paramutation and imprinting. We have determined the genome-wide cytosine methylation map of two maize inbred lines, B73 and Mo17, at high coverage and at single nucleotide resolution. Transposon methylation is highest in CG (65%) and CHG (50%) contexts (where H = A, C or T), while methylation in CHH (5%) contexts is guided by 24nt small interfering RNA (siRNA), and not by 21-22nt siRNA. We have found that CG (8%) methylation seems to deter insertion of Mutator transposons into exons, while CHH and CHG methylation at splice donor and acceptor sites strongly inhibits RNA splicing. Methylation differences between parents are inherited in recombinant inbred lines, but methylation switches, guided by siRNA, are widespread and persist for up to 8 generations. These differences influence splicing, and recurrent switching suggest that paramutation is much more common than previously supposed, and may contribute to heterosis. Our results provide a comprehensive high resolution resource for maize genome methylation, as well as a map of recurrent transgenerational epigenetic shifts (paramutation) in the two most commonly used inbred maize lines. Genome-wide cytosine methylation map in 2 maize strains by bisulfite sequencing, and RNA and small RNA profiles in the same tissue using Illumina platform.
Project description:This is a total RNA-seq data set of two inbred lines of maize, B73 and Mo17, extracted from experiment E-GEOD-39232 (https://www.ebi.ac.uk/arrayexpress/experiments/E-GEOD-39232/). E-GEOD-39232 is a larger study which also studied the expression of small RNAs and genome-wide cytosine methylation pattern in the two cultivars using high-throughput sequencing methods. For total RNA-seq, three biological replicates were used per cultivar. E-GEOD-39232 was originally submitted to NCBI Gene Expression Omnibus under accession number GSE39232 (http://www.ncbi.nlm.nih.gov/projects/geo/query/acc.cgi?acc=GSE39232) and later imported to ArrayExpress as E-GEOD-39232.
Project description:We investigated the ascomycete truffle Tuber melanosporum exploits DNA methylation and transcription to cope with the more than 45,000 repeated elements that are present in its genome. Whole-genome bisulfite sequencing and RNA-sequencing, were performed on different developmental stages of this symbiotic hypogeous fungus -fruitbody (FB), free-living mycelium (FLM), and ectomycorrhiza. Examination of DNA methylation and transcription of truffle in its free living mycelium (FLM), fruit body (FB), and ectomycorrhizal root tips (ECM)
Project description:We employed RNA-seq to transcriptionally profile a pure population of hand-dissected polyploid TGCs from embryonic day 9.5. These data provide a set of polyploid-specific TGCs transcripts that will aid in the understanding of TGCs differentiation and endoreplication. TGCs were micro-dissected from day E9.5 nine implantation sites from C57BL/6J mice. The portion of the TGCs in direct contact with the spongiotrophoblast layer and the labyrinth layer were manually removed to avoid collecting any polyploid cells from the former or multi-nucleated syncytiotrophoblast cells from the latter.
Project description:RNA-seq is a sensitive and accurate technique to compare steady state levels of RNA between different cellular states. However, as it does not provide an account of transcriptional activity per se, other technologies are needed to more precisely determine acute transcriptional responses. Here, we have developed an easy, sensitive and accurate novel method, iRNA-seq, for genome-wide assessment of transcriptional activity based on analysis of intron coverage from total RNA-seq data. To test our method, we have performed total RNA-seq and RNA polymerase II (RNAPII) ChIP-seq profiling of the acute transcriptional response of human adipocytes to TNFM-NM-1 treatment and analyzed these using iRNA-seq in addition to different publically availbale dataset. Comparison of the results derived from iRNA-seq analyses with results derived using current methods for genome-wide determination of transcriptional activity, i.e. Global Run-On (GRO)-seq and RNA polymerase II (RNAPII) ChIP-seq, demonstrate that iRNA-seq provides very similar results in terms of number of regulated genes and their fold change. However, unlike the current methods that are all very labor-intensive and demanding in terms of sample material and technologies, iRNA-seq is cheap and easy and requires very little sample material. In conclusion, iRNA-seq offers an attractive novel alternative to current methods for determination of changes in transcriptional activity at a genome-wide level. Genome-wide assesment of the acute transcriptional response to TNFa in human SGBS adiposytes using total RNA-seq data end RNAPII ChIP-seq
Project description:Transcriptional profiling of brain tissue of was performed by RNA-SEQ in females and males. The sex specific expressed and spliced genes were examined comparing drone and worker honeybees. Examination of mRNA profiles in heads of male and female honeybees pupae were compared.
Project description:Notch signalling plays crucial roles in mediating cell fate choices in all metazoans largely by specifying the transcriptional output of one cell in response to a neighbouring cell. The DNA-binding protein RBPJ is the principle effector of this pathway in mammals and together with the transcription factor moiety of Notch (NICD) it regulates the expression of target genes. The prevalent view presumes that RBPJ statically occupies consensus binding sites while exchanging repressors for activators in response to NICD. We present the first specific RBPJ chromatin immunoprecipitation and high-throughput sequencing study in mammalian cells. To dissect the mode of transcriptional regulation by RBPJ and identify its direct targets, whole genome binding profiles were generated for RBPJ, its coactivator p300, NICD and the histone H3 modifications H3K4me3, H3K4me1 and H3K27ac in myogenic cells under active or inhibitory Notch signalling conditions. Our results demonstrate dynamic binding of RBPJ in response to Notch activation at essentially all sites co-occupied by NICD. Additionally, we identify a distinct set of sites where RBPJ recruits neither NICD nor p300, and binds DNA statically, irrespective of Notch activity. These findings significantly modify our views on how RBPJ and Notch signalling mediate their activities and consequently impact on cell fate decisions. ChIP (chromatin immunoprecipitation) is followed by deep sequencing to generate genome-wide patterns of RBP-J binding in mouse C2C12 cells under various conditions. Cells were either Notch activated by exposure to immobilized ligand or by overexpression of NICDGFP, or Notch inhibited by treatment with DAPT. Notch activation and inhibition treatments were applied for 6h and 24h. In addition to RBP-J, p300 and NICDGFP were profiled by ChIP-Seq and gene expression was assessed by RNA-Seq.