Similar Datasets
Project description:Transposable elements (TEs) are ubiquitous in genomes. Many of these TEs remain active and are an important fraction of the transcriptomes with potential effects on the host genomes. The functional impact of TEs is well known for model organisms, however, in transcriptomes analysis of non-model organisms, this information is ignored due to the difficulty in identifying and quantifying TEs. Here we develop ExplorATE, a pipeline that allows the identification and quantification of active TEs in non-model organisms that can be easily implemented within the R environment. Based on simulated data, we show that our pipeline accurately identifies and quantifies TEs, over-performing the commonly used tools in model organisms. We show the implementation of ExplorATE using real data for RNA-seq samples from different tissues (liver, ovary, and brain) of Liolaemus parthenos, the only parthenogenetic lizard known to date in the entire clade Iguanidae (pleurodonta). Our results show that a significant fraction of the transcriptome contains repeats, however many of these are co-expressed with genes. The implementation of our pipeline in real data allowed the identification of the most abundant transposon families in each tissue. The ERV2, CR1, and SINE3 families were particularly abundant in the liver. A test data set is provided in the ExplorATE package.
2021-07-30 | GSE173261 | GEO
Project description:The tetrapod-restricted KRAB-containing zinc finger proteins (KRAB-ZFPs) are essential early embryonic controllers of transposable elements (TEs), which they repress via their cofactor KAP1 and associated effectors through histone and DNA methylation, a process thought to result in irreversible silencing. Using a target-centered functional screen, we matched several murine TEs with their cognate KRAB-ZFP. This revealed an unexpected level of granularity in their interactions, with KRAB-ZFPs recognizing TEs from more than one subfamily, TEs recruiting more than one KRAB-ZFP, and spatially and temporally differential KRAB-ZFP-mediated regulation of TEs and nearby genes. Most importantly, we discovered that the KRAB/KAP1 system controls TEs in adult tissues, in cell culture and in vivo, where they partner up to regulate the expression of cellular genes. Therefore, TEs and KRAB-ZFPs establish widely active transcription networks that regulate not only development but probably also many physiological events. Given the high degree of species-specificity of both TEs and KRAB-ZFPs, these results have important implications for studying and understanding the biology of higher vertebrates, including humans. Analysis of transcriptional profiles of KAP1 or ZFP932/Gm15446 KO cells or tissues, and ZFP932 and Gm15446 ChIPseq in murine ES and C2C12 cells.
2016-03-15 | E-GEOD-74278 | biostudies-arrayexpress
Project description:Chromatin accessibility is a hallmark of active regulatory function in the genome and variation of chromatin accessibility across individuals has been shown to contribute to complex traits and disease susceptibility. However, the mechanisms responsible for chromatin variation among different individuals and how this variation contributes to phenotypic diversity remain poorly understood. We examined chromatin accessibility variation in liver tissue from seven strains of adult mice that have phenotypic diversity in response to a high-fat/high-sucrose diet. Remarkably, nearly 40% of the loci with the greatest degree of chromatin variability across the strains are associated with transposable elements (TEs), with evolutionarily younger TEs being particularly enriched for regions of chromatin variation. We found that evolutionary younger and older TEs have differential chromatin accessibility profiles and are enriched for binding sites of different transcription factors, indicating the role of TEs in the evolution of regulatory networks in the liver. We also demonstrate that TE polymorphisms and epigenetic regulation of TEs contribute to regulatory variation across different strains through providing binding sites for liver transcription factors. Intriguingly, variable chromatin loci that are associated with liver metabolism are primarily TE-associated. We demonstrate that TEs contribute to regulatory variation in liver and have downstream effects on metabolism. Our data reveal TEs as a novel and important contributor to regulatory and phenotypic variation in the liver and suggest that regulatory variation at TEs is a major contributor to phenotypic variation in populations. Examination of chromatin accessibility with FAIRE-seq in livers of male mice (A/J, AKR/J, BALB/cJ, C57BL/6J, C3H/HeJ, CBA/J, DBA/2J, BXH2/TyJ, and BXH19/TyJ) fed a high-fat, high-sucrose diet.
2016-07-14 | E-GEOD-75770 | biostudies-arrayexpress
Project description:The diversity of small RNA-directed DNA methylation (RdDM) mechanisms have been underestimated due to the nearly complete transcriptional silencing of transposable elements (TEs) in the wild-type reference strains of Arabidopsis thaliana. In plants mutant for the SWI/SNF histone remodeler DDM1, TEs are globally activated due to loss of genome wide heterochromatin condensation. Transcriptionally activated TEs go through additional non-canonical forms of RdDM that are dependent on RNA Polymerase II expression. However, the global targets of the non-canonical RdDM pathway have not been explored. In an attempt to identify and contrast the targets of canonical and expression-dependent non-canonical RdDM, we performed MethylC-seq of genome-wide DNA methylation patterns from several RdDM mutants in either the TE-silent or the TE-active (ddm1) contexts. Arabidopsis wildtype and twenty RdDM pathway mutants
2016-07-22 | E-GEOD-79746 | biostudies-arrayexpress
Project description:The LIM domain and tumour suppressor protein Testin (Tes) is downregulated in a variety of human tumours and tumour cell lines. Depending on its conformation, Tes localises to stress fibres and focal adhesions where it forms protein complexes with other members of the actin cytoskeleton, such as zyxin and VASP, and thereby influences cellular processes like cell migration, adhesion or spreading. Tes is a modular protein and Tes variants lacking specific domains, localize to different locations in cells. To better understand the molecular basis of its function, we utilized an interaction proteomics approach combined with pathway analysis. This revealed proteins present in complexes in which Tes participates as a function of its modular structure as well as novel Tes interaction partners. We demonstrate that Tes interacts with a short isoform of the glucocorticoid receptor (GR), independently of the conventional full length GRα, a transcription factor important in regulating cellular metabolism and immune function. Tes also interacts with the focal adhesion protein and GR-coactivator Hic-5. In addition, we found that upon overexpression, Tes and Hic-5 induce opposite effects on cell spreading on a fibronectin matrix.
2018-10-26 | PXD005058 | Pride
Project description:Transposable elements (TEs) sequence capture
| PRJEB11704 | ENA
Project description:Polycomb Repressive Complex 2 (PRC2) maintains transcriptionally silent genes in a repressed state via deposition of histone H3 K27 trimethyl (me3) marks. PRC2 has also been implicated in silencing transposable elements (TEs) yet how PRC2 is targeted to TEs remains unclear. To address this question, we performed tandem affinity purification combined with mass spectrometry and identified proteins that physically interact with the Paramecium Enhancer-of-zeste Ezl1 enzyme, which catalyzes H3K9me3 and H3K27me3 deposition at TEs. We show that the Paramecium PRC2 core complex comprises four subunits, each required in vivo for catalytic activity. We also identify PRC2 cofactors, including the RNA interference (RNAi) effector Ptiwi09, which are necessary to target H3K9me3 and H3K27me3 to TEs. We find that the physical interaction between PRC2 and the RNAi pathway is mediated by a RING finger protein and that small RNA recruitment of PRC2 to TEs is analogous to the small RNA recruitment of H3K9 methylation SU(VAR)3-9 enzymes.
2022-04-06 | PXD031335 | Pride
Project description:Transposable elements (TEs) are often the primary determinant of genome size differences among eukaryotes. In plants, the proliferation of TEs is countered through epigenetic silencing mechanisms that prevent transposition. Recent studies using the model plant Arabidopsis thaliana have revealed that methylated TE insertions are often associated with reduced expression of nearby genes, and these insertions may be subject to purifying selection due to their effect on nearby genes. Less is known about the genome-wide patterns of epigenetic silencing of TEs in other plant species. Here, we compare the 24-nt siRNA complement from Arabidopsis thaliana and a closely related congener with a two- to three-fold higher TE copy number, A. lyrata. We show that TEs, and particularly siRNA-targeted TEs, are associated with reduced gene expression within both species and also with gene expression differences between orthologs. In addition, A. lyrata TEs are targeted by a lower fraction of uniquely matching siRNAs, which are associated with more effective silencing of TE expression. Overall, our results suggest that the efficacy of RNA-directed DNA methylation silencing is lower in A. lyrata, a finding that may shed light on the causes of differential TE proliferation among species. 4 A. lyrata mRNA-seq samples
2011-02-11 | E-GEOD-24571 | biostudies-arrayexpress