Filters
Technology
Platform
Mus musculus
30 Downloadable Samples
Illumina Genome Analyzer IIx
Description
Vertebrate ancestors had only cone-like photoreceptors. The duplex retina evolved in jawless vertebrates with the advent of highly photosensitive rod-like photoreceptors. Despite cones being the arbiters of high-resolution color vision, rods emerged as the dominant photoreceptor in mammals during a nocturnal phase early in their evolution. We investigated the evolutionary and developmental origins of rods in two divergent vertebrate retinae. In mice, we discovered genetic and epigenetic vestiges of short wavelength cones in developing rods and cell lineage tracing validated the genesis of rods from S-cones. Curiously, rods did not derive from S-cones in zebrafish. Our study illuminates several questions regarding the evolution of duplex retina and supports the hypothesis that, in mammals, the S-cone lineage was recruited via the Maf-family transcription factor NRL to augment rod photoreceptors. We propose that this developmental mechanism allowed the adaptive exploitation of scotopic niches during the nocturnal bottleneck early in mammalian evolution. Overall design: GFP positive cells from Nrlp-GFP or Nrlp-GFP;Nrl-KO mouse retinas at post-natal ages P2, P4, P6, P10, P14, and P28 were isolated by flow sorting by FACSAria II (Becton Dickinson). Total RNA was extracted by Trizol LS (Life Technologies) and analyzed by 2100 Bioanalyzer (Agilent Technologies Genomics). High quality of total RNA (RIN: >7.0) was subjected to sequencing library construction using 20 ng of total RNA as input. Libraries were constructed using a stranded modification of the Illumina TruSeq mRNA (Brooks, et al. Meth Mol Biol 2012). Each library was single-end sequenced in an independent lane of a GAIIx at a length of 76 bases. Fastq files were generated from reads passing chastity filter.
Publication Title
Recruitment of Rod Photoreceptors from Short-Wavelength-Sensitive Cones during the Evolution of Nocturnal Vision in Mammals.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples- Drosophila melanogaster
- 4 Downloadable Samples
- Illumina HiSeq 2000
Description
mRNA expression levels were determined by NGS for wildtype larvae as well as for larvae lacking HP1a [Su(var)205^04/Su(var)205^05 transheterozygotes]. Overall design: RNA samples from wildtype (OR) and HP1a mutant third instar larvae were examined, using duplicate biological samples and Illumina NGS.
Publication Title
Enrichment of HP1a on Drosophila chromosome 4 genes creates an alternate chromatin structure critical for regulation in this heterochromatic domain.
Sample Metadata Fields
Subject
View Samples- Drosophila melanogaster
- 8 Downloadable Samples
Affymetrix Drosophila Genome 2.0 Array (drosophila2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Sequence-specific targeting of dosage compensation in Drosophila favors an active chromatin context.
Sample Metadata Fields
Cell line
View Samples- Drosophila melanogaster
- 8 Downloadable Samples
- Affymetrix Drosophila Genome 2.0 Array (drosophila2)
Description
The Drosophila MSL complex mediates dosage compensation by increasing transcription of the single X chromosome in males approximately two-fold. This is accomplished through recognition of the X chromosome and subsequent acetylation of histone H4K16 on X-linked genes. Initial binding to the X is thought to occur at a subset of sites. However, the consensus sequence motif of entry sites (MSL recognition element or MRE) is only slightly enriched on the X (~2 fold), and only a fraction of them is utilized by the MSL complex. Here we ask whether chromatin context could distinguish between utilized and non-utilized copies of the motif, by comparing their relative enrichment for histone modifications and chromosomal proteins mapped in the NHGRI modENCODE project. Through a comparative analysis of the chromatin features in male S2 cells, which contain MSL complex, and female Kc cells, which lack the complex, we find that the presence of active chromatin modifications, together with an elevated local GC content in surrounding sequence, has strong predictive value for functional MSL entry sites, independent of MSL binding. We tested these sites for function in Kc cells by RNAi knockdown of Sxl, resulting in induction of MSL complex. We show that ectopic MSL expression in Kc cells leads to H4K16 acetylation around these sites, and a relative increase in X chromosome transcription. Collectively, our results support a model in which a pre-existing active chromatin environment, coincident with H3K36me3, contributes to MSL entry site selection. The consequences of MSL targeting of the male X chromosome include increase in nucleosome lability, enrichment for H4K16 acetylation and JIL-1 kinase, and depletion of linker histone H1 on active X-linked genes. Our finding serves as a model to understand how chromatin and local sequence features are involved in the selection of functional protein binding sites in the genome.
Publication Title
Sequence-specific targeting of dosage compensation in Drosophila favors an active chromatin context.
Sample Metadata Fields
Cell line
View Samples- Drosophila melanogaster
- 3 Downloadable Samples
- Illumina Genome Analyzer II
Description
MSL (Male-specific lethal) complex increases transcription on the single X chromosome of Drosophila males in order to equalize expression of X-linked genes between males (XY) and females (XX). The increase in transcript levels correlates with MSL- dependent acetylation of histone H4 at K16 within the bodies of active genes, but identification of the transcriptional step affected has not been possible. In this study, we use global run-on sequencing (GRO-seq) to examine the specific effect of MSL complex on RNA Polymerase II (RNAP II) on a genome-wide level. Results indicate that MSL complex enhances transcription by facilitating the progression of RNAP II across the bodies of active X-linked genes. Improving transcriptional output downstream of typical gene-specific control may explain how dosage compensation can be imposed on the diverse set of genes along an entire chromosome. Overall design: Global Run-On Sequencing (GRO-Seq) reads, i.e., RNA-Seq of nascent RNA transcripts, from D. Melanogaster SL2 cells. Two biological replicates were analyzed.
Publication Title
Comprehensive analysis of the chromatin landscape in Drosophila melanogaster.
Sample Metadata Fields
Subject
View Samples- Gallus gallus
- 9 Downloadable Samples
- Affymetrix Chicken Genome Array (chicken)
Description
A model of tumor metastasis based on v-src transformed immortalized cell lines was developed. The model consists of highly metastatic PR9692 cell line and a derived clone PR9692-E9 which has lost the metastatic abilities. Introduction of exogenous EGR1 gene into the non-metastasizing PR9692-E9 cells completely restores the metastatic potential. Revealed changes in gene expression provide insight into the molecular mechanisms contolling metastatic behavior of sarcoma cells.
Publication Title
The transcription factor EGR1 regulates metastatic potential of v-src transformed sarcoma cells.
Sample Metadata Fields
Cell line
View Samples- Gallus gallus
- 4 Downloadable Samples
- Affymetrix Chicken Genome Array (chicken)
Description
Metastatic progression is the leading cause of cancer mortality yet we have an incomplete view of the genetic events governing this process. An investigation was undertaken to explore the role of homeodemain only protein X (HOPX) in metastatic propensity and to identify other genes that may participate in metastasis development. The transcription factor HOPX was assessed for its possible involvement in metastasis formation using a knock-down induced by plasmid-delivered shRNAs. We used our original model system of chicken v-src-transformed tumour cell line PR9692 and its subclone (PR9692-E9) that have lost the ability to induce metastases after inoculation into syngeneic chickens without any significant change in primary tumour formation. We found that also a PR9692 cell line with decreased expression of HOPX gene (PR9692-shHOPX) lost its metastatic capacity in vivo (in chickens) and displayed a reduced cell migration in vitro. We compared the gene expression profiles of control (PR9692-shMOCK) and PR9692-shHOPX cells using oligonucleotide microarrays, assuming that genes with differential expression might be associated with metastasis. The data were compared with a previous study showing differences in gene expression between the PR9692 and PR9692-E9 cells. Bioinformatics was applied to identify gene expression patterns associated with metastasis. 234 genes were identified to show at least 2-fold change in both pairs of cell lines. The results were validated with real-time quantitative RT-PCR and the differential expression was confirmed for several genes. We were also able to demonstrate a significant change at protein level in case of three selected genes (NCAM, FOXG1, ITGA4). shRNA mediated knockdown of one of the identified HOPX regulated genes (integrin alpha 4) in the PR9692 cell line itself showed a marked inhibition of metastasis formation.
Publication Title
Downregulation of HOPX controls metastatic behavior in sarcoma cells and identifies genes associated with metastasis.
Sample Metadata Fields
Cell line
View Samples- Homo sapiens
- 6 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
Argonautes, a family of highly evolutionarily conserved proteins, are the central platform for small RNA-mediated gene regulatory mechanisms which occur mainly in the cytoplasm. To understand a potential role of Argonaute 1 (Ago1) protein in the nucleus of mammalian cells in regulating gene transcription and epigenetics, we performed integrated analyses of Ago1 ChIP-sequencing (GSE40536) and gene expression profiling in cells depleted of Ago1. For gene expression profiling, we knocked down the expression of Ago1 by siRNA in PC-3 cells and compared gene expression profiles in the cells depleted of Ago1 and cells receiving control treatments. We found that Ago1 depletion resulted in more downregulated genes which were enriched in gene responsible for promoting cell cycle progression, DNA replication and repair, and response to endogenous stimuli. Integrated analyses of Ago1-chromosomal interactions and gene expression changes in response to Ago1 depletion reveal a significant correlation between Ago1-bound genes and genes altered by Ago1 depletion. These genes are significantly enriched in cancer-related pathways. Our data suggests a nuclear function of Ago1 in regulating gene transcription.
Publication Title
Ago1 Interacts with RNA polymerase II and binds to the promoters of actively transcribed genes in human cancer cells.
Sample Metadata Fields
Cell line, Treatment
View Samples- Homo sapiens
- 34 Downloadable Samples
- Illumina humanRef-8 v2.0 expression beadchip
Description
Here we present a strategy to adapt hESCs to high-throughput screening (HTS) conditions, resulting in an assay suitable for the discovery of small molecules that drive hESC self-renewal or differentiation. Use of this new assay has led to the identification of several currently marketed drugs and natural compounds promoting short-term hESC maintenance and compounds directing early lineage choice. Global gene expression analysis upon drug treatment reveals overlapping and novel pathways correlated to hESC self-renewal and differentiation. Our results demonstrate feasibility of hESC-based HTS and enhance the available repertoire of chemical compounds for manipulating hESC fate.
Publication Title
High-throughput screening assay for the identification of compounds regulating self-renewal and differentiation in human embryonic stem cells.
Sample Metadata Fields
No sample metadata fields
View Samples
GSE42214- Triticum aestivum
- 12 Downloadable Samples
- Affymetrix Wheat Genome Array (wheat)
Description
Three wheat genotypes were exposed to water stress and root tissue collected for expression analysis
Publication Title
Introgression of novel traits from a wild wheat relative improves drought adaptation in wheat.
Sample Metadata Fields
Specimen part
View Samples