Cellular differentiation is associated with changes in transcript populations. Accurate quantification of transcriptomes during development can thus provide global insights into differentiation processes including the fundamental specification and differentiation events operating during plant embryogenesis. However, multiple technical challenges have limited the ability to obtain high quality early embryonic transcriptomes, namely the low amount of RNA obtainable and contamination from surrounding endosperm and seed-coat tissues. We compared the performance of three low-input mRNA sequencing (mRNA-seq) library preparation kits on 0.1 to 5 nanograms (ng) of total RNA isolated from Arabidopsis thaliana (Arabidopsis) embryos and identified a low-cost method with superior performance. This mRNA-seq method was then used to profile the transcriptomes of Arabidopsis embryos across eight developmental stages. By comprehensively comparing embryonic and post-embryonic transcriptomes, we found that embryonic transcriptomes do not resemble any other plant tissue we analyzed. Moreover, transcriptome clustering analyses revealed the presence of four distinct phases of embryogenesis which are enriched in specific biological processes. We also compared zygotic embryo transcriptomes with publicly available somatic embryo transcriptomes. Strikingly, we found little resemblance between zygotic embryos and somatic embryos derived from late-staged zygotic embryos suggesting that somatic and zygotic embryo transcriptomes are distinct from each other. In addition to the biological insights gained from our systematic characterization of the Arabidopsis embryonic transcriptome, we provide a data-rich resource for the community to explore. Overall design: mRNA-seq libraries were generated from three biological replicates of 50 Col-0 (wild type) embryos at eight different developmental stages (i.e. 8-cell/16-cell to mature green). Additionally, mRNA-seq libraries were prepared from total RNA isolated from 50 bent-cotyledon staged embryos and then diluted to 5, 1, 0.5 or 0.1 nanograms prior to library construction with three different library preparation methods.
The embryonic transcriptome of Arabidopsis thaliana.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
RNA-stabilized whole blood samples but not peripheral blood mononuclear cells can be stored for prolonged time periods prior to transcriptome analysis.
Sex, Age, Specimen part, Time
View SamplesAnalysis of effect of long-term cryopreservation on peripheral blood mononuclear cells at gene expression level. The hypothesis tested in the present study was that long-term cryopreservation has an influence on the transcriptome profile of peripheral blood mononuclear cells. Results indicated remarkable changes in expression patterns upon cryopreservation of PBMCs, with decreasing signal intensities over time.
RNA-stabilized whole blood samples but not peripheral blood mononuclear cells can be stored for prolonged time periods prior to transcriptome analysis.
Sex, Age, Specimen part, Time
View SamplesAnalysis of cryopreservation effects on peripheral blood mononuclear cells at gene expression level. The hypothesis tested in the present study was that cryopreservation has an influence on the transcriptome profile of peripheral blood mononuclear cells. Results indicated remarkable changes in expression patterns upon cryopreservation of PBMCs, with a strong loss of signal intensities to background levels for several transcripts.
RNA-stabilized whole blood samples but not peripheral blood mononuclear cells can be stored for prolonged time periods prior to transcriptome analysis.
Age, Specimen part
View SamplesAnalysis of long-term freezing on the stability of transcriptome profiles in PAXgene stabilized whole blood samples. In the present study it was tested if long-term freezing of PAXgene RNA tubes (up to one year) has an influence on the transcriptome profile of peripheral whole blood samples. Results indicated that gene expression profiles of whole blood samples stabilized with PAXgene RNA tubes remain stable for at least 1 year.
RNA-stabilized whole blood samples but not peripheral blood mononuclear cells can be stored for prolonged time periods prior to transcriptome analysis.
Sex, Age, Specimen part, Time
View SamplesIn mouse, spermatogonial stem/progenitor cells are the progenitor cell which develop to mature sperms through a series of mitotic and meiotic divisions and differentiation. Gfra1 is an established surface marker for mouse spermatogonial stem/progenitor cells. In this study, we used a transcriptomic approach to investigate the effect of aging on Gfra1-positive and -negative populations of mouse male germ cells.
Age affects gene expression in mouse spermatogonial stem/progenitor cells.
Sex, Age
View SamplesMutations in the poly(A) ribonuclease (PARN) gene cause telomere diseases including familial idiopathic pulmonary fibrosis (IPF) and dyskeratosis congenita (DC)1,2, but how PARN deficiency impacts telomere maintenance is unclear. Here, using somatic cells and induced pluripotent stem (iPS) cells from DC patients with PARN mutations, we show that PARN is required for the 3' end maturation of the telomerase RNA component (TERC). Patient cells as well as immortalized cells in which PARN is disrupted show decreased levels of TERC. Deep sequencing of TERC RNA 3' termini reveals that PARN is required for removal of posttranscriptionally acquired oligo(A) tails that target nuclear RNAs for degradation. Diminished TERC levels and the increased oligo(A) forms of TERC are normalized by restoring PARN, which is limiting for TERC maturation in cells. Our results reveal a novel role for PARN in the biogenesis of TERC, and provide a mechanism linking PARN mutations to telomere diseases. Overall design: mRNA sequencing of fibroblasts, induced pluripotent stem cells, and 293 cell line.
Poly(A)-specific ribonuclease (PARN) mediates 3'-end maturation of the telomerase RNA component.
No sample metadata fields
View SamplesThe fungal pathogen Ustilago maydis establishes a biotrophic relationship with its host plant maize. Hallmarks of the disease are large plant tumors in which fungal proliferation occurs. Plants have developed various defense pathways to cope with pathogens. We used microarrays to detail the global programme of gene expression during the infection process of Ustilago maydis in its host plant to get insights into the defense programs and the metabolic reprogramming needed to supply the fungus with nutrients.
Ustilago maydis infection strongly alters organic nitrogen allocation in maize and stimulates productivity of systemic source leaves.
Specimen part
View SamplesMicroRNAs are endogenously expressed small non-coding RNAs that regulate gene expression on the posttranscriptional level. The miR-17-92 cluster (encoding miR-17, -18a, -19a/b, -20a and miR-92a) is highly expressed in tumor cells and is up-regulated by ischemia. Whereas miR-92a was recently identified as negative regulator of angiogenesis, the specific functions of the other members of the cluster are less clear. Here we demonstrate that overexpression of miR-17, -18a, -19a and -20a significantly inhibited 3D spheroid sprouting in vitro, whereas inhibition of miR-17, -18a and -20a augmented endothelial cell (EC) sprout formation. Inhibition of miR-17 and miR-20a in vivo using antagomirs significantly increased the number of perfused vessels in matrigel plugs, whereas antagomirs, that specifically target miR-18a and miR-19a were less effective. However, systemic inhibition of miR-17/20 did not affect tumor angiogenesis. Further mechanistic studies showed that miR-17/20 targets several pro-angiogenic genes. Specifically, Janus kinase 1 (Jak1) was shown to be a direct target of miR-17. In summary, we show that miR-17/20 exhibit a cell intrinsic anti-angiogenic activity in ECs. Inhibition of miR-17/20 specifically augmented neovascularization of matrigel plugs, but did not affect tumor angiogenesis indicating a context-dependent regulation of angiogenesis by miR-17/20 in vivo.
Members of the microRNA-17-92 cluster exhibit a cell-intrinsic antiangiogenic function in endothelial cells.
Specimen part
View SamplesThe routine workflow for invasive cancer diagnostics is based on biopsy processing by formalin fixation and subsequent paraffin embedding. Formalin-fixed paraffin-embedded (FFPE) tissue samples are easy to handle, stable and particularly suitable for morphologic evaluation, immunohistochemistry and in situ hybridization. However, it has become a paradigm that these samples cannot be used for genome-wide expression analysis with microarrays. To oppose this view, we present a pilot microarray study using FFPE core needle biopsies from breast cancers as RNA source. We found that microarray probes interrogating sequences near the poly-A-tail of the transcribed genes were well suitable to measure RNA levels in FFPE core needle biopsies. For the ER and the HER2 gene, we observed strong correlations between RNA levels measured in these probe sets and protein expression determined by immunohistochemistry (p = 0.000003 and p = 0.0022). Further, we have identified a signature of 364 genes that correlated with ER protein status and a signature of 528 genes that correlated with HER2 protein status. Many of these genes (ER: 60%) could be confirmed by analysis of an independent publicly available data set. Finally, a hierarchical clustering of the biopsies with respect to three recently reported gene expression grade signatures resulted in widely stable low and high expression grade clusters that correlated with the pathological tumor grade. These findings support the notion that clinically relevant information can be gained from microarray based gene expression profiling of FFPE cancer biopsies. This opens new opportunities for the integration of gene expression analysis into the workflow of invasive cancer diagnostics as well as translational research in the setting of clinical studies.
Genome-wide gene expression profiling of formalin-fixed paraffin-embedded breast cancer core biopsies using microarrays.
Disease stage
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