Cumulus cells and mural granulosa cells (MGCs) are spatially and functionally distinct cell types in antral follicles: cumulus cells contact the oocyte and most MGCs contact the basal lamina. For transcriptomic analyses, both cell types were collected from small and large antral follicles, before and after stimulation of immature mice with eCG, respectively. Both cell types underwent dramatic transcriptomic changes and the differences between them became greater with follicular growth. Although cumulus cells of both stages of follicular development are competent to undergo expansion in vitro, they were otherwise remarkably dissimilar with transcriptomic changes quantitatively equivalent to those of MGCs. Gene Ontology (GO) analysis showed that cumulus cells of small follicles were enriched in transcripts generally associated with catalytic components of metabolic processes while those from large follicles were involved in regulation of metabolism, cell differentiation, and adhesion. Upon contrasting cumulus cells versus MGCs, cumulus cells were enriched in transcripts associated with metabolism and cell proliferation while MGCs were enriched for transcripts involved in cell signaling and differentiation.
Transcriptomic diversification of developing cumulus and mural granulosa cells in mouse ovarian follicles.
Specimen part
View SamplesOocyte-derived paracrine factors and estrogens cooperate to regulate the function and development of mouse cumulus cells.
Cooperative effects of 17β-estradiol and oocyte-derived paracrine factors on the transcriptome of mouse cumulus cells.
Sex, Specimen part, Treatment
View SamplesThere is massive destruction of transcripts during maturation of mouse oocytes. The objective of this project was to identify and characterize the transcripts that are degraded versus those that are stable during the transcriptionally silent germinal vesicle (GV)-stage to metaphase II (MII)-stage transition using the microarray approach. A system for oocyte transcript amplification using both internal and 3-poly(A) priming was utilized to minimize the impact of complex variations in transcript polyadenylation prevalent during this transition. Transcripts were identified and quantified using Affymetrix Mouse Genome 430 v2.0 GeneChip. The significantly changed and stable transcripts were analyzed using Ingenuity Pathways Analysis and GenMAPP/MAPPFinder to characterize the biological themes underlying global changes in oocyte transcripts during maturation. It was concluded that the destruction of transcripts during the GV to MII transition is a selective rather than promiscuous process in mouse oocytes. In general, transcripts involved in processes that are associated with meiotic arrest at the GV-stage and the progression of oocyte maturation, such as oxidative phosphorylation, energy production, and protein synthesis and metabolism, were dramatically degraded. In contrast, transcripts encoding participants in signaling pathways essential for maintaining the unique characteristics of the MII-arrested oocyte, such as those involved in protein kinase pathways, were the most prominent among those stables.
Selective degradation of transcripts during meiotic maturation of mouse oocytes.
No sample metadata fields
View SamplesMouse oocytes control cumulus cell metabolic processes that are deficient in the oocytes themselves and this delegation is necessary for oocyte development. Oocyte-derived bone morphogenetic factor 15 (BMP15) and growth differentiation factor 9 (GDF9) appear to be key regulators of follicular development. The effect of these factors on cumulus cell function before the preovulatory surge of luteinizing hormone (LH) was assessed by analysis of the transcriptomes of cumulus cells from wildtype (WT), Bmp15-/-, and Bmp15-/- Gdf9+/- double mutant (DM) mice using microarray analysis. The biological themes associated with the most highly-affected transcripts were identified using bioinformatic approaches, IPA and GenMAPP/MAPPFinder. There were 5,332, 7,640, and 2,651 transcripts identified to be significantly changed in the comparisons of Bmp15-/- vs. WT, DM vs. WT, and DM vs. Bmp15-/- respectively by the criteria of FC (fold change) p <0.01. Among theses changed transcripts, 744 were commonly changed in all three pair-wise comparisons, and hence were considered to be the most highly affected transcripts by mutation of Bmp15 and Gdf9. IPA Analyses revealed that metabolism was the major theme associated with the most highly-changed transcripts: glycolysis and sterol biosynthesis were the two most significantly affected pathways. Most of the transcripts encoding enzymes for sterol biosynthesis were down-regulated in both mutant cumulus cells and in WT cumulus cell after oocytectomy. Similarly, there was a reduction of de novo-synthesized cholesterol in these cumulus cells. This suggests that oocytes regulate cumulus cell metabolism, particularly sterol biosynthesis, by promoting the expression of corresponding transcripts. Furthermore, in WT-mice, Mvk, Pmvk, Fdps, Sqle, Cyp51, Sc4mol, and Ebp, which encode enzymes in the sterol biosynthetic pathway, were found to be expressed robustly in cumulus cells, but expression was barely detectable in oocytes. Levels of de novo-synthesized cholesterol were significantly higher in cumulusenclosed oocytes than denuded oocytes. These results indicate that mouse oocytes are deficient in their ability to synthesize cholesterol and require cumulus cells to provide them with products of the sterol biosynthetic pathway. Oocyte-derived BMP15 and GDF9 may promote this metabolic pathway in cumulus cells as compensation for their own deficiencies.
Oocyte regulation of metabolic cooperativity between mouse cumulus cells and oocytes: BMP15 and GDF9 control cholesterol biosynthesis in cumulus cells.
No sample metadata fields
View SamplesWe isolated mutants in Arabidopsis with enhanced ambient temperature response. Microarray analysis was performed to understand the extent to which ambient temperature transcriptome is perturbed in the mutants in comparison with the WT at non inductive 12 C and after shift to inductive 27 C for 2 h and 24 h.
H2A.Z-containing nucleosomes mediate the thermosensory response in Arabidopsis.
Specimen part
View SamplesThrough post-transcriptional regulation of gene expression, miRNAs affect numerous regulatory pathways including those crucial for maintaining metabolic balance. Here we demonstrate that a neuronal-specific inhibition of miRNA maturation in adult mice leads to a rapid development of severe obesity, which is equally rapidly reversed. Development of obesity was associated with increased food intake and efficiency, and decreased locomotor activity. The ensuing decrease in body weight resembled a catabolic state with lowered O2-consumption and respiratory-exchange ratio. Brain transcriptome analyses in obese mice identified several obesity-related pathways including leptin, somatostatin, and nemo-like kinase signaling, as well as genes involved in feeding and appetite (e.g. Pmch, Neurotensin). A cluster of genes involved in synaptic plasticity was specifically enriched in post-obese mice that did not appear in obese mice. While other studies have identified a role for miRNAs in obesity our model is unique in that it allows for the study of processes involved in reversing obesity.
A neuron-specific deletion of the microRNA-processing enzyme DICER induces severe but transient obesity in mice.
Specimen part, Time
View SamplesResponse to photoperiod in Arabidopsis wildtype, co, and ft mutant plants.
Integration of spatial and temporal information during floral induction in Arabidopsis.
Specimen part
View SamplesPlants are sessile organisms and therefore must sense and respond to changes of their surrounding conditions such as ambient temperature, which vary diurnally and seasonally. It is not yet clear how plants sense temperature and integrate this information into their development. We have previously shown that H2A.Z-nucleosomes are evicted in response to warmer temperatures. It is not clear however, whether the link between transcriptional responsiveness and changes in H2A.Z binding in context of temperature shifts is a global trend that can be seen throughout the genome, or the phenomenon is specific to a specialised set of temperature-responsive genes. In addition to the role of H2A.Z-nucleosome dynamics in the transcriptional response to temperature, it was shown that genes strongly misregulated in the h2a.z mutant are enriched for gene categories involved in response to multiple environmental cues. This suggests that H2A.Z could be implicated in the transcriptional response to various environmental inputs, raising the question: What brings the specificity of H2A.Z dynamics in response to temperature? To address this question we have profiled H2A.Z-nucleosome occupancy genome wide (using ChIP-seq) during a time course after temperature variation and compared its dynamics to transcriptional changes. We identified a fast, targeted and transient eviction of H2A.Z associated with transcriptional activation in response to temperature for a few hundreds genes. This eviction is associated with a reduction of the stability of the nucleosome. Moreover the genes with a fast H2A.Z eviction were strongly enriched in heat shock elements in their promoter and we observed a strong association between HSF1 binding and H2AZ eviction at warm temperature. These results highlight the importance of the interplay between transcription factors and chromatin to allow a controlled and dynamics response to temperature. Overall design: RNA-seq were generated in duplicate for seedlings shifted to warm temperature
Transcriptional Regulation of the Ambient Temperature Response by H2A.Z Nucleosomes and HSF1 Transcription Factors in Arabidopsis.
Subject
View SamplesPlants are sessile organisms and therefore must sense and respond to changes of their surrounding conditions such as ambient temperature, which vary diurnally and seasonally. It is not yet clear how plants sense temperature and integrate this information into their development. We have previously shown that H2A.Z-nucleosomes are evicted in response to warmer temperatures. It is not clear however, whether the link between transcriptional responsiveness and changes in H2A.Z binding in context of temperature shifts is a global trend that can be seen throughout the genome, or the phenomenon is specific to a specialised set of temperature-responsive genes. In addition to the role of H2A.Z-nucleosome dynamics in the transcriptional response to temperature, it was shown that genes strongly misregulated in the h2a.z mutant are enriched for gene categories involved in response to multiple environmental cues. This suggests that H2A.Z could be implicated in the transcriptional response to various environmental inputs, raising the question: What brings the specificity of H2A.Z dynamics in response to temperature? To address this question we have profiled H2A.Z-nucleosome occupancy genome wide (using ChIP-seq) during a time course after temperature variation and compared its dynamics to transcriptional changes. We identified a fast, targeted and transient eviction of H2A.Z associated with transcriptional activation in response to temperature for a few hundreds genes. This eviction is associated with a reduction of the stability of the nucleosome. Moreover the genes with a fast H2A.Z eviction were strongly enriched in heat shock elements in their promoter and we observed a strong association between HSF1 binding and H2AZ eviction at warm temperature. These results highlight the importance of the interplay between transcription factors and chromatin to allow a controlled and dynamics response to temperature. Overall design: RNA-seq were generated in duplicate for seedlings shifted to warm temperature
Transcriptional Regulation of the Ambient Temperature Response by H2A.Z Nucleosomes and HSF1 Transcription Factors in Arabidopsis.
Subject
View SamplesEnvironmental factors shape the phenotypes of multicellular organisms. The production of stomata—the epidermal pores required for gas exchange in plants—is highly plastic, and provides a powerful platform to address environmental influence on cell differentiation [1-3]. Rising temperatures are already impacting plant growth, a trend expected to worsen in the near future [4]. High temperature inhibits stomatal production but the underlying mechanism is not known [5]. Here, we show that elevated temperature suppresses the expression of SPEECHLESS (SPCH), the bHLH transcription factor that serves as the master regulator of stomatal lineage initiation [6,7]. Our genetic and expression analyses indicate that the suppression of SPCH and stomatal production is mediated by the bHLH transcription factor PHYTOCHROME-INTERACTING FACTOR 4 (PIF4), a core component of high temperature signaling [8]. Importantly, we demonstrate that upon exposure to high temperature, PIF4 accumulates in the stomatal precursors and binds to the promoter of SPCH. In addition, we find SPCH feeds back negatively to the PIF4 gene. We propose a model where the high temperature-activated PIF4 binds and represses SPCH expression to restrict stomatal production at high temperature. Our work identifies a molecular link connecting high temperature signaling and stomatal development, and reveals a direct mechanism by which production of a specific cell lineage can be controlled by a broadly-expressed environmental signaling factor. Overall design: Gene expression profiles following 12 hr Dex-induction of control and ML1p:SPCH1-4A-expressing Arabidopsis plants grown in liquid culture. Four replicates per line at 0 and 12 hr.
Direct Control of SPEECHLESS by PIF4 in the High-Temperature Response of Stomatal Development.
Age, Subject
View Samples