After ovulation, somatic cells of the ovarian follicle (theca and granulosa cells) become the small and large luteal cells of the corpus luteum. Aside from known cell type-specific receptors and steroidogenic enzymes, little is known about the differences in the gene expression profiles of these four cell types. Analysis of the RNA present in each bovine cell type using Affymetrix microarrays yielded new cell-specific genetic markers, functional insight into the behavior of each cell type via Gene Ontology Annotations and Ingenuity Pathway Analysis, and evidence of small and large luteal cell lineages using Principle Component Analysis. Enriched expression of select genes for each cell type was validated by qPCR. This expression analysis offers insight into the lineage and differentiation process that transforms somatic follicular cells into luteal cells.
Gene expression profiling of bovine ovarian follicular and luteal cells provides insight into cellular identities and functions.
No sample metadata fields
View SamplesPlant cells contain different O-acetylserine(thiol)lyase (OASTL) enzymes involved in Cys biosynthesis and located in different subcellular compartments. These enzymes are made up of a complex variety of isoforms resulting in different subcellular Cys pools. To unravel the contribution of cytosolic Cys to plant metabolism, we characterized the knockout oas-a1.1 and osa-a1.2 mutants, deficient in the most abundant cytosolic OASTL isoform in Arabidposis thaliana. Total intracellular Cys and glutathione concentrations were reduced, and the glutathione redox state was shifted in favour of its oxidized form. Interestingly, the capability of the mutants to chelate heavy metals did not differ from that of the wild type, but the mutants have an enhanced sensitivity to Cd. With the aim of establishing the metabolic network most influenced by the cytosolic Cys pool, we used the ATH1 GeneChip for evaluation of differentially expressed genes in the oas-a1.1 mutant grown under non-stress conditions. The transcriptomic footprints of mutant plants had predicted functions associated with various physiological responses that are dependent on reactive oxygen species and suggested that the mutant was oxidatively stressed. To further elucidate the specific function(s) of the OAS-A1 isoform in the adaptation response to cadmium we extended the trasncriptome experiment to the wild type and oas-a1.1 mutant plants exposed to Cd. The comparison of transcriptomic profiles showed a higher proportion of genes with altered expression in the mutant than in the wild type, highlighting up-regulated genes identified as of the general oxidative stress response rather than metal-responsive genes.
Knocking out cytosolic cysteine synthesis compromises the antioxidant capacity of the cytosol to maintain discrete concentrations of hydrogen peroxide in Arabidopsis.
Specimen part
View SamplesIn bacteria, the biosynthesis of cysteine is accomplished by two enzymes that are encoged by the cysK and cysM genes. CysM is also able to incorporate thiosulfate to produce S-sulfocysteine. In plant cells, the biosynthesis of cysteine occurs in the cytosol, mitochondria and chloroplasts. Chloroplasts contain two O-acetylserine(thiol)lyase homologs, which are encoded by the OAS-B and CS26 genes. An in vitro enzymatic analysis of the recombinant CS26 protein demonstrated that this isoform possesses S-sulfocysteine synthase activity and lacks O-acetylserine(thiol)lyase activity. In vivo functional analysis of this enzyme in knockout mutants demonstrated that mutation of cs26 suppressed the S-sulfocysteine synthase activity that was detected in wild type; furthermore, the mutants exhibited a growth phenotype, but penetrance depended on the light regime. The cs26 mutant plants also had reductions in chlorophyll content and photosynthetic activity (neither of which were observed in oas-b mutants), as well as elevated glutathione levels. However, cs26 leaves were not able to properly detoxify ROS, which accumulated to high levels under long-day growth conditions. The transcriptional profile of the cs26 mutant revealed that the mutation had a pleiotropic effect on many cellular and metabolic processes. Our finding reveals that S-sulfocysteine and the activity of S-sulfocysteine synthase play an important role in chloroplast function and are essential for light-dependent redox regulation within the chloroplast.
Arabidopsis S-sulfocysteine synthase activity is essential for chloroplast function and long-day light-dependent redox control.
No sample metadata fields
View SamplesHere we show using RNA-seq that cleavage by RNase E direct entry pervades in both the degradation and processing of RNA. We also give further evidence that direct entry is facilitated by cooperative interaction with segments in addition to the ones in which cleavage occurs. Overall design: RNA-seq profiles were compared between a temperature-sensitive mutant of rne and its congenic wild-type incubated at a non-permissive temperature. RNA seq profiles were also compared between samples before and after incubation with a 5''-sensing mutant of RNase E in vitro.
Direct entry by RNase E is a major pathway for the degradation and processing of RNA in Escherichia coli.
Cell line, Subject
View SamplesThe use of low quality RNA samples in whole-genome gene expression profiling remains controversial. It is unclear if transcript degradation in low quality RNA samples occurs uniformly, in which case the effects of degradation can be normalized, or whether different transcripts are degraded at different rates, potentially biasing measurements of expression levels. This concern has rendered the use of low quality RNA samples in whole-genome expression profiling problematic. Yet, low quality samples are at times the sole means of addressing specific questions – e.g., samples collected in the course of fieldwork.
RNA-seq: impact of RNA degradation on transcript quantification.
No sample metadata fields
View SamplesDeafness due to the terminal loss of inner ear hair cells is one of the most common sensory diseases. However, non-mammalian animals (e.g. birds, amphibian and fish) regenerate damaged hair cells. In order to better understand the reasons underpinning such regeneration disparities in vertebrates, we set out to define the changes in gene expression associated with the regeneration of hair cells in the zebrafish lateral line at high resolution. We performed RNA-Seq analyses on regenerating support cells purified by fluorescence activated cell sorting (FACS). The zebrafish lateral line provides an experimentally accessible system to define the complex signaling events triggered by injury and regeneration, because these cells can be acutely killed by exposure to neomycin, after which they regenerate rapidly. Lateral line hair cells are located in the center of a mechanosensory organ known as the neuromast and are surrounded by inner support cells and an outer ring of mantle cells. Tg(sqET20) larvae express GFP strongly in mantle cells and to a lesser degree in inner support cells. We isolated GFP positive and GFP negative cells from 5 days post fertilization (dpf) Tg(sqET20) larvae at 1, 3 and 5 hours post neomycin treatment, as well as from a non-treated control. Overall design: Transgenic zebrafish Tg(sqET20) larvae at 5 days post fertilization were exposed to neomycin, dissociated, and FACS sorted into GFP positive and GFP negative populations at 1, 3, and 5 hours following treatment, along with a mock treated 1 hr control. The experiment was performed in triplicate, for a total of 24 samples.
Gene-expression analysis of hair cell regeneration in the zebrafish lateral line.
No sample metadata fields
View SamplesCysteine occupies a central position in plant metabolism due to its biochemical functions. Arabidopsis thaliana cells contain different O-acetylserine(thiol)lyase (OASTL) enzymes that catalyze the biosynthesis of cysteine. Because they are localized in the cytosol, plastids and mitochondria, this results in multiple subcellular cysteine pools. Much progress has been made on the most abundant OASTL enzymes; however, information on the less abundant OASTL-like proteins has been scarce. To unequivocally establish the enzymatic reaction catalyzed by the minor cytosolic OASTL isoform CS-LIKE (AT5G28030), we expressed this enzyme in bacteria and characterized the purified recombinant protein. Our results demonstrate that CS-LIKE catalyzes the desulfuration of L-cysteine to sulfide plus ammonia and pyruvate. Thus, CS-LIKE is a novel L-cysteine desulfhydrase (EC 4.4.1.1), and we propose to designate it DES1. The impact and functionality of DES1 in cysteine metabolism was revealed by the phenotype of the T-DNA insertion mutants des1-1 and des1-2. Mutation of the DES1 gene leads to premature leaf senescence, as demonstrated by the increased expression of senescence-associated genes and transcription factors. Also, the absence of DES1 significantly reduces the total cysteine desulfuration activity in leaves, and there is a concomitant increase in the total cysteine content. As a consequence, the expression levels of sulfur-responsive genes are de-regulated, and the mutant plants show enhanced antioxidant defenses and tolerance to conditions that promote oxidative stress. Our results suggest that DES1 from Arabidopsis is an L-cysteine desulfhydrase involved in maintaining cysteine homeostasis, mainly at late developmental stages or under environmental perturbations.
Cysteine homeostasis plays an essential role in plant immunity.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Sleep is not just for the brain: transcriptional responses to sleep in peripheral tissues.
Specimen part, Treatment, Time
View SamplesMolecular profiles in sleep and sleep deprivation in peripheral tissues using microarrays
Sleep is not just for the brain: transcriptional responses to sleep in peripheral tissues.
Specimen part, Treatment, Time
View SamplesMolecular profiles in sleep and sleep deprivation in peripheral tissues using microarrays
Sleep is not just for the brain: transcriptional responses to sleep in peripheral tissues.
Specimen part, Treatment, Time
View Samples