Temporal ChIP-on-Chip of RNA-Polymerase-II to detect novel gene activation events during photoreceptor maturation
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE19999 | GEO | 2010/02/09
SECONDARY ACCESSION(S): PRJNA120167
REPOSITORIES: GEO
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Project description: Not available
| S-EPMC2822553 | biostudies-literature
Project description:The rd1 mouse retina is a well-studied model of retinal degeneration where rod photoreceptors undergo cell death beginning at postnatal day P10 until P21. This period coincides with photoreceptor terminal differentiation in a normal retina. We have used the rd1 retina as a model to investigate early molecular defects in developing rod photoreceptors prior to the onset of degeneration. Using a microarray approach, we performed gene profiling comparing rd1 and wild type retinas at four time points starting at P2, prior to any obvious biochemical or morphological differences, and concluding at P8, prior to the initiation of cell death. We have identified genes that are differentially regulated in the rd1 retina at early time points, which may give insights into developmental defects that precede photoreceptor cell death. This is the first report of PRA1 expression in the retina. Our data support the hypothesis that PRA1 plays an important role in vesicular trafficking between the Golgi and cilia in differentiating and mature rod photoreceptors. Retinal samples were harvested from both rd1/le and wt animals at postnatal days 2, 4, 6, and 8 for microarray. Each sample included 8-14 retinas and experiments were performed in quadruplicate. Ten micrograms of total RNA was used for cDNA systhesis in target molecule production.
2012-11-02 | E-GEOD-41821 | biostudies-arrayexpress
Project description:The rd1 mouse retina is a well-studied model of retinal degeneration where rod photoreceptors undergo cell death beginning at postnatal day P10 until P21. This period coincides with photoreceptor terminal differentiation in a normal retina. We have used the rd1 retina as a model to investigate early molecular defects in developing rod photoreceptors prior to the onset of degeneration. Using a microarray approach, we performed gene profiling comparing rd1 and wild type retinas at four time points starting at P2, prior to any obvious biochemical or morphological differences, and concluding at P8, prior to the initiation of cell death. We have identified genes that are differentially regulated in the rd1 retina at early time points, which may give insights into developmental defects that precede photoreceptor cell death. This is the first report of PRA1 expression in the retina. Our data support the hypothesis that PRA1 plays an important role in vesicular trafficking between the Golgi and cilia in differentiating and mature rod photoreceptors.
2012-11-02 | GSE41821 | GEO
Project description:To enrich mouse rod and cone photoreceptors for mass spectrometric analysis, we optimized our previously established trituration-based fluorescence-activated cell sorting (FACS) strategy (see Lux et al., 2024 for details; PMID: 38481472). For quantitative mass spectrometry, we utilized an ion mobility-enhanced version of a data-independent acquisition (DIA) workflow with alternating low and elevated energy (referred to as UDMSE). Label-free protein quantification of rod and cone photoreceptor in comparison with retina samples revealed an enrichment of photoreceptor-specific proteins. More importantly, established photoreceptor markers were significantly enriched in the respective photoreceptor samples, which confirms the quality and specificity of our proteome resource. Among the proteins highly enriched in the cone photoreceptor samples, we identified Mpp6/Pals2, a protein uncharacterized in photoreceptors so far, and established it as a novel pan-cone photoreceptor marker by immunocytochemistry. As an example of the use of our resource for the characterization of retina- and photoreceptor-specific protein isoforms, we assessed the expression of the two known isoforms of Mpp6/Pals2, the canonical Pals2β and the 14 aa shorter splice variant Pals2α. We confidently identified a tryptic peptide that only occurs upon splicing, indicating the expression of the non-canonical Pals2α in cone photoreceptors. In summary, our proteome resource provides comprehensive details on the protein (isoform) composition of mouse rod and cone photoreceptors, making it a valuable research tool for the study of retina biology and pathology.
2025-12-08 | PXD066755 | Pride
Project description:Purpose: 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. mRNA expression profiling of 5 pairs of photoreceptor subtypes isolated from chicken retinal explants, 3 replicates per sample
2014-09-01 | E-GEOD-59850 | biostudies-arrayexpress
Project description: Not available
| S-EPMC8051094 | biostudies-literature
Project description:Purpose: To investigate the gene regulatory networks during photoreceptor differentiation. Special aims: To generate gene expression profiles of purified photoreceptors at distinct developmental stages and from different genetic backgrounds. Background: Rod photoreceptor genesis spans a broad temporal window during retinal development. It starts as early as E12.5 and peaks at P0-P2. At E16.5, there are some early born rods but the peak of rod genesis does not occur. At P2, the majority of rod photoreceptors are born. At P6, rod specific structural/functional genes begin to express. At P10, Outer segments morphogenesis is taking place. At 4 weeks, retinal development is complete and retina is functional. Nrl is a rod specific transcription factor and one of the earliest markers of rod photoreceptors. Nrl promoter drives the expression of GFP exclusively to rod photoreceptors shortly after they exit cell cycle. In the Nrl-knockout background, the expression of GFP is detected in S-opsin positive cells, which suggested a cell fate transformation from rods to cones in the absence of Nrl. Design: GFP positive photoreceptors from the WT-Gfp or Nrl-knockout-Gfp retina were enriched (purified) by FACS at five distinct developmental stages (E16, P2, P6, P10, and 4 weeks). Total RNA was extracted by Trizol reagent. Around 50 ng of total RNA was used for linear amplification and biotin labeling followed Nugen kit protocol. Fragmented cDNA was hybridized on Affymetrix mouse genomic expression array 430 2.0 and then scanned with the standard protocol. Four replicates were performed for each time point. Conclusion: By comparing the gene expression profiles from different developmental stages, we can obtain novel insights into molecular events underlying photoreceptor differentiation. Keywords: Transcription factor, development, photoreceptor, retina, neuron, differentiation, gene regulation, microarray, gene profiling, cell type comparison
2006-02-28 | GSE4051 | GEO
Project description:Cone photoreceptors are specialised sensory retinal neurons responsible for photopic vision, colour perception and visual acuity. Retinal degenerative diseases are a heterogeneous group of eye diseases in which the most severe vision loss typically arises from cone photoreceptor dysfunction or degeneration. Establishing a method to purify cone photoreceptors from retinal tissue can accelerate the identification of key molecular determinants that underlie cone photoreceptor development, survival and function. The work herein describes a new method to purify enhanced green fluorescent protein (EGFP)-labelled cone photoreceptors from adult retina of Tg(3.2TαCP:EGFP) zebrafish. Electropherograms confirmed downstream isolation of high-quality RNA with RNA integrity number (RIN) >7.6 and RNA concentration >5.7 ng/µl obtained from both populations. Reverse Transcriptase-PCR (RT-PCR) confirmed that the EGFP-positive cell populations express known genetic markers of cone photoreceptors that were not expressed in the EGFP-negative cell population. This work is an important step towards the identification of cone photoreceptor-enriched genes, protein and signalling networks responsible for their development, survival and function. In addition, this advancement facilitates the identification of novel candidate genes for inherited human blindness. In order to analyse and sort samples by flow cytometry, values for FSC and SSC were displayed in a logarithmic scale, as this is normally the default starting display. This allowed for the identification of different sub-populations of cells present in the retina, which were mixed with unwanted cell debris and cell fragments. Since there were multiple cell populations, different levels of auto-fluorescence were thus successfully detected. It was therefore important to change the strategy and display side scatter and fluorescence characteristics of control and EGFP samples, which ultimately allowed the identification of the extremely well-defined population of EGFP-cone photoreceptors. This improved sorting process minimised RNA degradation. The purified EGFP+ cone photoreceptors represent ~5% of the original dissociated population, which is consistent with humans, wherein the total number of cones (6 million) in the retina is approximately 20 times the one of rods (120 million) (Williamson and Cummins 1983). This work allows high-quality RNA to be obtained from sorted-adult cone photoreceptors. RNA integrity is assessed via 28S and 18S rRNA (Imbeaud et al 2005), and our electropherogram results demonstrate production of high-quality RNA with two clearly visible ribosomal peaks (28S and 18S) from EGFP-sorted cones. In addition, the RNA Integrity Number (RIN), an algorithm for assigning integrity values to RNA based on 28S to 18S rRNA ratios (Sambrook et al 1989; Imbeaud et al 2005; Schroeder et al 2006), had a value of 7.6, higher than the minimum-required 7.0. RNA yields of 5.7 ng/µl were relatively high and sufficient for downstream profiling. RT-PCR confirmed expression of the cone specific gene gnat2, and promoter fragment TαC, but not the retinal pigment epithelium specific gene rpe65 in flow cytometry-sorted GFP-positive photoreceptors (GFP+ cells). rpe65 was neither present in flow cytometry-sorted GFP-negative cones (GFP- cells) as this gene is only expressed in the retinal pigment epithelium (RPE). This study therefore permits the identification of cone photoreceptor-enriched genes, protein and signalling networks responsible for their development, survival and function. In addition, this advancement facilitates the identification of novel candidate genes for inherited human blindness.
2017-10-31 | GSE86155 | GEO
Project description:Mouse rod photoreceptors isolated from retinas of Prkaa2 rod photoreceptor specific knockout mice were processed for phosphoproteomics to elucidate downstream kinase targets. Prkaa2 is an isoform of the catalytic subunit of AMP-activated protein kinase (AMPK), an essential nutrient-sensing enzyme responsible for maintaining many metabolic processes.
2024-06-16 | PXD045669 | Pride
Project description:This data set provides most accurate absolute quantification of outer segment proteins of rod photoreceptors of retina.
2022-12-12 | MSV000090885 | MassIVE