In this study we used genetic approaches and transcriptome profiling to unravel the complex interaction of different developmental pathways required for chloroplast development in plants. The recently described snowy cotyledon 3 (sco3) mutant as well as the Phytochrome B (phyb) mutant revealed, in the double mutant, a complex suppressive or additive genetically linked regulation of chloroplast development, flowering time and transcription regulation.
No associated publication
Age, Specimen part
View SamplesAim: To identify the genes and non-coding RNAs (ncRNAs) involved in the neuroprotective actions of a dietary anti-oxidant (saffron) and of photobiomodulation.
Gene and noncoding RNA regulation underlying photoreceptor protection: microarray study of dietary antioxidant saffron and photobiomodulation in rat retina.
Specimen part
View SamplesThe retinas of simian primates include a specialized, cone-rich, macula which regards the central visual field and mediates high acuity and colour vision. A prominent feature of the macula is the fovea centralis - a 1 mm-wide, avascular depression in the inner retinal surface that corresponds with a local absence of rods and a peak spatial density of cones in the outer photoreceptor layer. The arrangement of macular photoreceptors, and their specialized midget circuits, are the neural substrate for high resolution vision in primates. Macular-specific photoreceptor loss and abnormal blood vessel growth within the macula are the major causes of untreatable vision loss worldwide. However, the genes that regulate specialization of the macula, and the causes of its vulnerability to degeneration, remain obscure. Microarrays were used to compare gene expression between macula and non-macular regions during a critical phase of human retinal vascular development.
Differential expression of anti-angiogenic factors and guidance genes in the developing macula.
Specimen part
View SamplesPURPOSE: Hyperoxia is toxic to photoreceptors, and this toxicity may be important in the progress of retinal dystrophies. This microarray study examines gene expression induced in the C57BL/6J mouse retina by hyperoxia over the 14-day period during which photoreceptors first resist, then succumb to, hyperoxia. METHODS: Young adult C57BL/6J mice were exposed to hyperoxia (75% oxygen) for up to 14 days. On day 0 (control), day 3, day 7, and day 14, retinal RNA was extracted and processed on Affymetrix GeneChip Mouse Genome 430 2.0 arrays. Microarray data were analyzed using GCOS Version 1.4 and GeneSpring Version 7.3.1. RESULTS: The overall numbers of hyperoxia-regulated genes increased monotonically with exposure. Within that increase, however, a distinctive temporal pattern was apparent. At 3 days exposure, there was prominent upregulation of genes associated with neuroprotection. By day 14, these early-responsive genes were downregulated, and genes related to cell death were strongly expressed. At day 7, the regulation of these genes was mixed, indicating a possible transition period from stability at day 3 to degeneration at day 14. CONCLUSIONS: Microarray analysis of the response of the retina to prolonged hyperoxia demonstrated a temporal pattern involving early neuroprotection and later cell death, and provided insight into the mechanisms involved in the two phases of response. As hyperoxia is a consistent feature of the late stages of photoreceptor degenerations, understanding the mechanisms of oxygen toxicity may be important therapeutically.
Gene regulation induced in the C57BL/6J mouse retina by hyperoxia: a temporal microarray study.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
A unique H2A histone variant occupies the transcriptional start site of active genes.
Sex, Age, Specimen part
View SamplesChromatin performs numerous functions during cellular differentiation, and therefore it must be capable of adopting a multitude of different structures. How these various structures are established is poorly understood, but we propose that specific histone H2A variants will have a key role in remodelling chromatin during differentiation. Structurally, we show here that the gain of just a single acidic amino acid residue has generated a new mouse H2A.Bbd-like histone variant, H2A.Lap1, and that when incorporated into nucleosomal arrays imparts on them unique biophysical properties that are distinct from arrays containing either H2A or human H2A.Bbd. Functionally, we identify H2A.Lap1 as a novel chromatin component of active genes that are expressed during spermatogenesis, and in combination with H2A.Z create a unique chromatin landscape at the start site of transcription. During round spermatid differentiation, H2A.Lap1 dramatically loads onto the inactive X chromosome enabling a subset of its genes to be transcriptionally activated.
A unique H2A histone variant occupies the transcriptional start site of active genes.
Sex, Age, Specimen part
View SamplesIgG cytoplasmic tail interferes with the induction of antigen-response genes
Enhancement and suppression of signaling by the conserved tail of IgG memory-type B cell antigen receptors.
No sample metadata fields
View SamplesBackground information:
No associated publication
Specimen part, Treatment, Subject
View SamplesGene expression profiling analysis reveals ?-3 polyunsaturated fatty acids attenuates a high fat diet induced fatty liver
No associated publication
No sample metadata fields
View SamplesEndothelial cells comprise a key component of the inflammatory response. HUVEC (human umbilical vein endothelial cells) were stimulated with interleukin-1 for 0, 0.5, 1, 2.5 and 6 hours, and analyzed using Affymetrix U133A microarrays, in order to obtain a comprehensive overview of the immediate early to early gene expression profiles. HUVEC were isolated and cultured on gelatine-coated cell culture dishes in M199 medium supplemented with 20% FCS, antibiotics, ECGS (endothelial cell growth supplement) and Heparin as described by Zhang et al., Blood 1996;88:3880-3886. HUVEC were stimulated with 100 U/ml human IL-1 (Biosource) for various periods of time, and total RNA isolated using the RNeasy kit (Qiagen) according to the manufacturer's instructions. Hybridization to one set of human U133A GeneChips (Affymetrix, Santa Clara, CA) and scanning of the arrays was carried out according to manufacturers protocols (https://www.affymetrix.com). Briefly, 5 g of total RNA was used to generate double-stranded cDNA by reverse transcription using a cDNA synthesis kit (Superscript Choice System; Life Technologies, Inc., Rockville, MD) that uses an oligo(dT)24 primer containing a T7 RNA polymerase promoter 3' to the polyT (Geneset, La Jolla, CA), followed by second-strand synthesis. Labeled cRNA was prepared from the double-stranded cDNA by in vitro transcription using T7 RNA polymerase in the presence of biotin-11-CTP and biotin-16-UTP (Enzo, Farmington, NY). The labeled cRNA was purified over RNeasy columns (Qiagen, Valencia, CA). Fifteen g of cRNA was fragmented at 94C for 35 minutes in 40 mmol/L of Tris-acetate, pH 8.1, 100 mmol/L of potassium acetate, and 30 mmol/L of magnesium acetate. The cRNA was then used to prepare 300 l of hybridization cocktail (100 mmol/L MES, 1 mol/L NaCl, 20 mmol/L ethylenediaminetetraacetic acid, 0.01% Tween 20) containing 0.1 mg/ml of herring sperm DNA (Promega, Madison, WI) and 500 g/ml of acetylated bovine serum albumin (Life Technologies, Inc.). Before hybridization, the cocktails were heated to 94C for 5 minutes, equilibrated at 45C for 5 minutes, and then clarified by centrifugation (16,000 x g) at room temperature for 5 minutes. Aliquots of this hybridization cocktail containing 15 g of fragmented cRNA were hybridized to HU133A arrays (Affymetrix, Santa Clara, CA) at 45C for 16 hours in a rotisserie oven at 60 rpm. The arrays were washed using non-stringent buffer (6xSSPE: 0.9 M sodium chloride, 0.06 M sodium phosphate, 6 mM EDTA pH 7.4) at 25C, followed by stringent buffer (100 mmol/L MES, pH 6.7, 0.1 mol/L NaCl, 0.01% Tween 20) at 50C. The arrays were stained with streptavidin-phycoerythrin (Molecular Probes, Eugene, OR), washed with 6xSSPE, incubated with biotinylated anti-streptavidin IgG, stained again with streptavidin-phycoerythrin, and washed again with 6xSSPE. The arrays were scanned using the GeneArray scanner (Affymetrix). Image analysis was performed with GeneChip software (Affymetrix, MAS 5.0). Normalization was performed by global scaling, with the arrays scaled to an average intensity of 500.
Deciphering regulatory patterns of inflammatory gene expression from interleukin-1-stimulated human endothelial cells.
No sample metadata fields
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