Conserved generation of short products at piRNA loci
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
SUBMITTER: Philipp Berninger
PROVIDER: E-GEOD-26160 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Publications
Conserved generation of short products at piRNA loci.
Berninger Philipp P Jaskiewicz Lukasz L Khorshid Mohsen M Zavolan Mihaela M
BMC genomics 20110119
<h4>Background</h4>The piRNA pathway operates in animal germ lines to ensure genome integrity through retrotransposon silencing. The Piwi protein-associated small RNAs (piRNAs) guide Piwi proteins to retrotransposon transcripts, which are degraded and thereby post-transcriptionally silenced through a ping-pong amplification process. Cleavage of the retrotransposon transcript defines at the same time the 5' end of a secondary piRNA that will in turn guide a Piwi protein to a primary piRNA precurs ...[more]
Similar Datasets
Project description:Homologous recombination is the key process that generates genetic diversity and drives evolution. SPO11 protein triggers recombination by introducing DNA double stranded breaks at discreet areas of the genome called recombination hotspots. The hotspot locations are largely determined by the DNA binding specificity of the PRDM9 protein in human, mice and most other mammals. In budding yeast Saccharomyces cerevisae, which lacks a Prdm9 gene, meiotic breaks are formed opportunistically in the regions of accessible chromatin, primarily at gene promoters. The genome-wide distribution of hotspots in this organism can be altered by tethering Spo11 protein to Gal4 recognition sequences in the strain expressing Spo11 attached to the DNA binding domain of the Gal4 transcription factor. To establish whether similar re-targeting of meiotic breaks can be achieved in PRDM9-containing organisms we have generated a Gal4BD-Spo11 mouse that expresses SPO11 protein joined to the DNA binding domain of yeast Gal4. We have mapped the genome-wide distribution of the recombination initiation sites in the Gal4BD-Spo11 mice. More than two hundred of the hotspots in these mice were novel and were likely defined by Gal4BD, as the Gal4 consensus motif was clustered around the centers in these hotspots. Surprisingly, meiotic DNA breaks in the Gal4BD-Spo11 mice were significantly depleted near the ends of chromosomes. The effect is particularly striking at the pseudoautosomal region of the X and Y chromosomes – normally the hottest region in the genome. Our data suggest that specific, yet-unidentified factors influence the initiation of meiotic recombination at subtelomeric chromosomal regions. Detection of meiotic double strand breaks in mice with a hypomorphic Spo11 allele.
2013-09-11 | E-GEOD-48493 | biostudies-arrayexpress
Project description:Our experimental design includes samples at different time points during the first wave of spermatogenesis. Each time point corresponds to specific cell content in the testis. First time point is post natal day (PND) 7, when only somatic cells and spermatogonia are present in the testis. Thereafter additional cell types are present in selected samples in chronological order: PND 14 contains early spermatocytes, PND 17 late spermatocytes, PND 21 round spermatids and finally PND 28 elongating spermatids. Our results highlight differentially expressed genes and gene isoforms, which are important for correct sperm development and male fertility. In addition, functional analysis suggests a highly controlled gene expression pattern during the first wave of spermatogenesis. Transcriptome sequencing of the mouse testes at PND 7, 14, 17, 21 and 28 for analysis of differences in gene expression pattern during the first wave of spermatogenesis. In total 10 samples were analysed, replicates for each time point.
2013-04-29 | E-GEOD-39970 | biostudies-arrayexpress
Project description:Meiotic DNA double stranded breaks (DSBs) initiate genetic recombination in discrete areas of the genome called recombination hotspots. Although DSBs can be directly mapped using ChIP-Seq and antibody against ssDNA-associated proteins, genome-wide mapping of recombination hotspots in mammals is still a challenge due to the low frequency of recombination, high heterogeneity of the germ cell population and the relatively low efficiency of ChIP. To overcome these limitations we have developed a novel method, single-stranded DNA (ssDNA) sequencing (SSDS), that specifically detects protein-bound single-stranded DNA at DSB ends. SSDS consists of a computational framework for the specific detection of ssDNA-derived reads in a sequencing library and a new library preparation procedure for the enrichment of fragments originating from ssDNA. When applied to mapping meiotic DSBs, the use of SSDS reduces the non-specific dsDNA background more than ten-fold. Our method can be extended to other systems where the identification of ssDNA or DSBs is desired. Development and validation of the method, SSDS, for the specific detection of ssDNA-derived and dsDNA-derived fragments in sequencing libraries and enrichment of ssDNA-derived fragments. SSDS was used to detect meiotic DSBs in 9R/13R mice.
2012-02-21 | E-GEOD-34592 | biostudies-arrayexpress
Project description:DNA methylation occurs in both CG and non-CG sequence contexts. Non-CG methylation is abundant in plants, and is mediated by CHROMOMETHYLASE (CMT) and DOMAINS REARRANGED METHYLTRANSFERASE (DRM) proteins; however its roles remain poorly understood. Here we characterize the roles of non-CG methylation in Arabidopsis thaliana. We show that a poorly characterized methyltransferase, CMT2, is a functional methyltransferase in vitro and in vivo. CMT2 specifically binds histone H3 lysine 9 (H3K9) dimethylation and methylates non-CG cytosines at sites that are also regulated by H3K9 dimethylation. By generating different combinations of non-CG methylation mutants, we reveal the contributions and redundancies between each methyltransferase in DNA methylation patterning and in regulating transposable elements (TEs) and protein-coding genes. We also demonstrate extensive dependencies of small RNA accumulation and H3K9 methylation patterning on non-CG methylation, suggesting self-reinforcing mechanisms between these epigenetic factors. The results suggest that non-CG methylation patterns are critical in shaping the histone modification and small non-coding RNA landscapes. Eighteen mRNA-seq samples, five smRNA-seq samples, five bisulfite-seq samples, twenty ChIP-seq samples. Bisulfite-seq data for cmt2-7 single mutants, cmt3 single mutants, drm1/2 double mutants, drm1/2 cmt3 triple mutants are deposited in GSE39901. Processed wiggle format files for all datasets can be downloaded at http://genomes.mcdb.ucla.edu/AthBSseq/
2013-12-15 | E-GEOD-51304 | biostudies-arrayexpress
Project description:In order to study molecular changes in the stroma from tissue samples it is recommended to separate tumor tissue from stromal tissue. This is particularly relevant to mouse tumor xenograft models where tumor, particularly metastatic tumors, can be small and difficult to separate from the host tissue. In our research we compared qualitatively the ability of high-throughput mRNA sequencing, RNA-Seq, and microarrays to detect tumor (human) and stromal (mouse) expression from mixed tumor-stromal samples in terms of the genes and pathways that are involved in cross-alignment (RNA-Seq) and cross-hybridization (microarrays). Human samples consisted of total RNA obtained from MDA-MB-231 human breast carcinoma cell line and isolated from three independent cultures of sub-confluent MDA-MB-231 cell lines in exponential phase of growth. Mouse samples were obtained from NOD scid gamma mice, and normal lung tissue was harvested from three independent age-matched mice.
2012-12-14 | E-GEOD-40890 | biostudies-arrayexpress
Project description:Transposable elements (TEs) have been active in the mammalian genome for hundreds of millions of years and each TE has had a distinct period of transpositional activity, followed by inactivation. Mice carrying reporter transgenes can be used to model transcriptional silencing at TEs. A mutagenesis screen for modifiers of epigenetic gene silencing produced a line with a null mutation in Trim33. Heterozygous mutants displayed increased expression of the reporter transgene. ChIP-seq of Trim33 in testis revealed 9,109 peaks, mostly at promoters, across the mouse genome. Trim33 was enriched at many RLTR10B elements that are among the youngest retrotransposons in the mouse genome. RNA-seq revealed that testis of mice haploinsufficient for Trim33 had altered expression of a small group of genes. The gene with the most significant increase, Nmnat3, was found to be transcribed from an upstream RLTR10B element. We show that Trim33 is involved in repressing RLTR10B elements in mouse testis. Examination of Trim33 binding using ChIP sequencing and the result of Trim33 haploinsufficiency using RNA sequencing, in mouse testis
2015-11-06 | E-GEOD-68617 | biostudies-arrayexpress
Project description:Taf7l (a paralogue of Taf7) and Trf2 (a TBP-related protein) are components of the core promoter complex required for gene/tissue-specific transcription of protein-coding genes by RNA polymerase II. Previous studies reported that Taf7l knockout mice exhibit structurally abnormal sperm, reduced sperm count, weakened motility and compromised fertility. Here we find that continued backcrossing of Taf7l-/Y mice from N5 to N9 produced KO males that are essentially sterile. Genome-wide expression profiling by mRNA-seq analysis of wild type (WT) and Taf7l-/Y (KO) testes revealed that Taf7l ablation impairs the expression of many post-meiotic spermatogenic specific as well as metabolic genes. Importantly, histological analysis of testes revealed that Taf7l-/Y mice develop post-meiotic arrest at the first stage of spermiogenesis, phenotypically similar to Trf2-/- mice, but distinct from Taf4b-/- mice. Indeed, we find that Taf7l and Trf2 co-regulate post-meiotic genes, but none of Taf4b-regulated germ stem cell genes in testes. Genome-wide ChIP-seq studies indicate that TAF7L binds to promoters of activated post-meiotic genes in testis. Moreover, biochemical studies show that TAF7L associates with TRF2 both in vitro and in testis suggesting that TAF7L likely cooperates directly with TRF2 at promoters of a subset of post-meiotic genes to regulate spermiogenesis. Our findings thus provide a new mechanism for cell-type specific transcriptional control involving an interaction between a ‘non-prototypic’ core promoter recognition factor (Trf2) and an orphan TAF subunit (Taf7l) in mammalian testis-specific gene transcription. Genome-wide mapping of TAF7L and Pol II in testis tissue, and mRNA-seq expression profiling wild type and Taf7l knockout testis.
2013-09-29 | E-GEOD-50807 | biostudies-arrayexpress
Project description:The relationship between epigenetic marks on chromatin and the regulation of DNA replication is poorly understood. Mutation of the H3K27 methyltransferase genes, ARABIDOPSIS TRITHORAX-RELATED PROTEIN5 (ATXR5) and ATXR6, result in re-replication (repeated origin firing within the same cell cycle). Here we show that mutations that reduce DNA methylation act to suppress the re-replication phenotype of atxr5 atxr6 mutants. This suggests that DNA methylation, a mark enriched at the same heterochromatic regions that re-replicate in atxr5/6 mutants, is required for aberrant re-replication. In contrast, RNA sequencing analyses suggest that ATXR5/6 and DNA methylation cooperatively transcriptionally silence transposable elements (TEs). Hence our results suggest a complex relationship between ATXR5/6 and DNA methylation in the regulation of DNA replication and transcription of TEs. DNA-seq: One gram of mature rosette leaves were collected from 3-4-week-old plants, chopped in 0.5 ml of filtered Galbraith buffer, and stained with propidium iodide. A BD FACS Aria II in the UCLA Jonsson Comprehensive Cancer Center (JCCC) Flow Cytometry Core Facility was used to sort the nuclei. For sequencing, 7,000-9,000 8C nuclei of each sample were collected, and purified DNA with Picopure purification kit (Arcturus) following manufacturer instructions. RNA-seq: RNA-seq experiments were performed in two biological replicates for each genotype. 0.1g of tissue was ground in Trizol. Total RNA were treated with DNaseI (Roche), and cleaned up with phenol-chlorophorm and precipitated with ethanol. Libraries were generated and sequenced following manufacturer instructions (Illumina). BS-seq: 0.5-1g of mature rosette leaves were collected, and genomic DNA was extracted using Plant DNeasey mini purification kit (Qiagen). Libraries were generated as previously described (Feng et al., Methods Mol Biol. 2011;733:223-38.).
2012-08-07 | E-GEOD-38286 | biostudies-arrayexpress
Project description:We examined the role of PELP1 in E2-ER-mediated transcription in the hippocampus under conditions of GCI by perfroming global transcriptome analysis. E2-treated FLOX and PELP1 FBKO mice were subjected to GCI followed by 24 h reperfusion and the isolated RNA was utilized for RNA-seq analysis. Our results demonstrated that PELP1 is needed for optimal activation of E2-regulated genes following GCI. Total RNA was isolated from the hippocampus of ovariectomized FLOX and PELP1 FBKO mice (implanted with E2 mini pumps) that were subjected to GCI followed by 24 h reperfusion. Illumina TruSeq RNA Sample Preparation was performed following manufacturer's protocol. Samples were run on an Illumina HiSeq 2000 in duplicate. The combined raw reads were aligned to UCSC hg19 and genes were annotated by Tophat. Genes were annotated and quantified by HTSeq-DESeq pipeline.
2015-12-07 | E-GEOD-72136 | biostudies-arrayexpress
Project description:We have studied the regulatory potential of MYST1-(MOF)-containing MSL and NSL complexes in mouse embryonic stem cells (ESCs) and neuronal progenitors. We find that both complexes influence transcription by binding to promoters as well as TSS-distal enhancer regions. In contrast to flies, the MSL complex is not enriched on the X chromosome yet it is crucial for mammalian X chromosome regulation as it specifically regulates Tsix ncRNA, the major repressor of Xist lncRNA. MSL depletion leads to severely decreased Tsix expression, reduced REX1 recruitment, and consequently accumulation of Xist RNA in ESCs. The NSL complex provides additional, Tsix-independent repression of Xist by maintaining pluripotency. MSL and NSL complexes therefore act synergistically by using distinct pathways to ensure a fail-safe mechanism for the repression of X inactivation in ESCs. We have performed ChIP-seq of KANSL3, MCRS1, MOF, MSL1 and MSL2 in mouse ESCs, and KANSL3, MOF and MSL2 in NPCs, in duplicate and normalised against their inputs. We have also performed RNA-seq following knockdown of Kansl3, Mof, Msl1 and Msl2 mouse embryonic stem cells in triplicate. NB: Kansl3 and Mof knockdown-RNAseq are analyzed against their own scrambled controls, and Msl1 and Msl2 against another scrambled control triplicate.
2014-06-03 | E-GEOD-57698 | biostudies-arrayexpress