A fundamental challenge in genomics is to map DNA sequence variants onto changes in gene expression. Gene expression is regulated by cis-regulatory elements (CREs, i.e., enhancers, promoters, and silencers) and the trans factors (e.g., transcription factors) that act upon them. A powerful approach to dissecting cis and trans effects is to compare F1 hybrids with F0 homozygotes. Using this approach and taking advantage of the high frequency of polymorphisms in wild-derived inbred Cast/EiJ mice relative to the reference strain C57BL/6J, we conducted allele-specific mRNA-seq analysis in the adult mouse retina, a disease-relevant neural tissue. We found that cis effects account for the bulk of gene regulatory divergence in the retina. Many CREs contained functional (i.e., activating or silencing) cis-regulatory variants mapping onto altered expression of genes, including genes associated with retinal disease. By comparing our retinal data with previously published liver data, we found that most of the cis effects identified were tissue-specific. Lastly, by comparing reciprocal F1 hybrids, we identified evidence of imprinting in the retina for the first time. Our study provides a framework and resource for mapping cis-regulatory variants onto changes in gene expression, and underscores the importance of studying cis-regulatory variants in the context of retinal disease. Overall design: Retinas from four classes of 8 week old male mice were collected: F0 C57BL/6J (B6), F0 Cast/EiJ (Cast), F1 B6xCast, and F1 CastxB6. Three replicates per class were generated. Each replicate consisted of a pool of 6-8 retinas. The mRNA-seq was conducted with paired-end 2x101 sequencing on the Illumina HiSeq 2000 platform. One lane of sequencing was run for all twelve samples. An additional lane of sequencing was run for the six F1 samples.
Hybrid mice reveal parent-of-origin and Cis- and trans-regulatory effects in the retina.
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View SamplesPurpose: Avian photoreceptors are a diverse class of neurons, comprised of four single cones, the two members of the double cone, and rods. Many distinctive features of photoreceptor subtypes, including spectral tuning, oil droplet size and pigmentation, synaptic targets and spatial patterning, have been well characterized, but the molecular mechanisms underlying these attributes have not been explored. Furthermore, the signaling events and transcriptional regulators driving the differentiation of these diverse photoreceptors are currently unknown. Methods: To identify genes specifically expressed in distinct chicken (Gallus gallus) photoreceptor subtypes, we developed fluorescent reporters that label photoreceptor subpopulations, isolated these subpopulations using fluorescence-activated cell sorting, subjected them to next-generation sequencing, and conducted differential expression analysis. Results: We identified hundreds of differentially expressed genes from photoreceptor subpopulations labeled with rhodopsin, red opsin, green opsin, and violet opsin reporters. These genes are involved in a variety of processes, including phototransduction, transcriptional regulation, cell adhesion, maintenance of intra- and extra-cellular structure, and metabolism. Of particular note are a variety of differentially expressed transcription factors, which may drive and maintain photoreceptor diversity, and cell adhesion molecules that may mediate spatial patterning of photoreceptors and act to establish retinal circuitry. Conclusions: These analyses provide a framework for future studies that will dissect the role of these various factors in the differentiation of avian photoreceptor subtypes. Overall design: mRNA expression profiling of 5 pairs of photoreceptor subtypes isolated from chicken retinal explants, 3 replicates per sample
Transcriptome profiling of developing photoreceptor subtypes reveals candidate genes involved in avian photoreceptor diversification.
Specimen part, Subject
View SamplesThe polyadenosine RNA binding proteins (Pabs) represent one class of RNA binding proteins that play critical roles in gene expression. This class includes the well-studied nuclear and cytoplasmic Pabs, PABPN1 and PABPC1, respectively, as well as the newly characterized nuclear Pab, zinc finger CCCH-type containing #14, or ZC3H14. ZC3H14 was recently linked to a form of intellectual disability, suggesting a critical role for ZC3H14 in neurons; however, the post-transcriptional function of ZC3H14 is unknown. In this study, we performed a microarray analysis of cells depleted of ZC3H14 or PABPN1 in MCF-7 breast cancer cells. These results revealed that PABPN1 significantly affected ~17% of expressed transcripts as compared to ZC3H14, which affected ~1% of expressed transcripts, suggesting that ZC3H14 has specific mRNA targets. The differentially expressed mRNAs identified in this analysis not only provide information about the classes and types of transcripts that are regulated by these proteins, but also represent a set of transcripts that could be directly bound by ZC3H14 and/or PABPN1.
The Polyadenosine RNA-binding Protein, Zinc Finger Cys3His Protein 14 (ZC3H14), Regulates the Pre-mRNA Processing of a Key ATP Synthase Subunit mRNA.
Cell line
View SamplesThe sensation of light is initiated in photoreceptor cells by the photoisomerization of a chromophore molecule from 11-cis to all-trans retinal. Continuous visual perception requires recycling of the spent chromophore back to the 11-cis form through the visual cycle, a series of reactions in the retinal pigmented epithelium (RPE). Light-driven chromophore consumption by photoreceptors is greater in daytime compared to night time, suggesting that correspondingly higher activity of the visual cycle may be required. On the other hand, as rod photoreceptors are saturated in bright light, the continuous turnover of their chromophore through the visual cycle during daytime would unnecessarily utilize precious energy and produce toxic byproducts. Here, we sought to determine whether the recycling of chromophore and the dark adaptation of rods is regulated by the circadian clock and light exposure. We demonstrate that in melatonin-proficient C3H/f+/+ mice, rod dark adaptation is slower during the day or after light exposure. This surprising daytime downregulation of the RPE visual cycle was further demonstrated by gene analysis, which revealed light-driven reduction in the expression of Rpe65, which encodes a key enzyme of the RPE visual cycle. In contrast, rods in melatonin-deficient strains (C57BL6/J and 129/Sv) were not affected by this daily visual cycle modulation. Our results demonstrate that the circadian clock and light exposure regulate the recycling of chromophore in the RPE visual cycle. This daily modulation of rod dark adaptation is mediated by melatonin and could potentially protect the retina from light-induced damage during the day. Overall design: mRNA-seq of murine eyes (lens removed) in objective day (OD) vs. subjective day (SD) conditions (2 biological replicates per condition). Each biological replicate consisted of 4 eyes (from 1 female and 1 male).
Circadian and light-driven regulation of rod dark adaptation.
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View SamplesMicroarray experiments were performed using FAC-sorted young photoreceptors to analyze their transcriptome in comparison to remaining retinal cells at same developmental stage and retinal progenitors.
Increased integration of transplanted CD73-positive photoreceptor precursors into adult mouse retina.
Specimen part
View SamplesOur study demonstrated that e-cigarettes, both with and without nicotine, induced sex-dependent gene expression change. This RNA-seq study examined the expression profiles of brain frontal cortex samples from mice exposed to classic tobacco flavored bluâ„¢ e-cigarettes during gestation and lactation. Overall design: Brains were extracted and sectioned from ~1-month-old male and female offspring the week following exposure, RNA was isolated and purified from frontal cotrex tissues, and gene expression profiles were analyzed by RNA Sequencing.
Microglia Activation and Gene Expression Alteration of Neurotrophins in the Hippocampus Following Early-Life Exposure to E-Cigarette Aerosols in a Murine Model.
Sex, Specimen part, Cell line, Subject
View SamplesThe BM-derived CD45+/Sca1+ cells are haematopoietic stem/progenitor cells that have the ability to circulate and migrate and engraft to the muscle tissue, and therefore they are of particular interest. Notably, these cells retain their haematopoietic potential, as revealed both by in vitro and in vivo assays; but they also acquire myogenic potential, as shown by their ability to participate in muscle regeneration. Whether, this latter remarkable ability is the result of the reprogramming of the BM-CD45+/Sca1+ cells and the activation of a myogenic molecular program within these cells, remains controversial. This study aims to clarify this aspect of the process, investigating the role of the muscle microenviroment and key myogenic transcription factors.
Bone marrow-derived hematopoietic cells undergo myogenic differentiation following a Pax-7 independent pathway.
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View SamplesOpi10 is the S. pombe homolog of human Hikeshi, which imports Hsp70s into the nucei during the heat shock.
The Schizosaccharomyces pombe Hikeshi/Opi10 protein has similar biochemical functions to its human homolog but acts in different physiological contexts.
No sample metadata fields
View SamplesTemporal changes of the expression levels of the complete human transcriptome during the first 24 hours following infection of IFN-pre-treated macrophages. This approach has allowed us to identify genes involved in the IFN signaling that have an impact on HIV-1 infection of macrophages
TRAF6 and IRF7 control HIV replication in macrophages.
Specimen part, Time
View SamplesThe aim of this study was to investigate the molecular mechanisms implicated in this mouse model of nemaline myopathy, and to further compare the molecular disease response in different skeletal muscles. For this purpose, snap frozen skeletla muscle specimens from wild type and transgenic for alpha tropomyosin slow mice were studied. Five different muscle types were used (diaphragm, plantaris, extensor digitorum longus, tibialis anterior, gastrocnemus). Mice were sacrificed between 7 and 10 months. RNA pools from 3-5 animals were created and each pool was hybridized to a U74Av2 Affymetrix GeneChip. Datasets from 36 GeneChips were included in this study.
Skeletal muscle repair in a mouse model of nemaline myopathy.
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