The wheat gene Lr34 (Yr18/Pm38/Sr57/Ltn1) encodes a putative ABCG-type of transporter and is a unique source of disease resistance providing durable and partial resistance against multiple fungal pathogens. Lr34 has been found to be functional as a transgene in barley.
The wheat resistance gene Lr34 results in the constitutive induction of multiple defense pathways in transgenic barley.
Specimen part
View SamplesPlant defenses against pathogens and insects are regulated differentially by cross-communicating signaling pathways in which salicylic acid (SA), jasmonic acid (JA) and ethylene (ET) play key roles. To understand how plants integrate pathogen- and insect-induced signals into specific defense responses, we monitored the dynamics of SA, JA, and ET signaling in Arabidopsis after attack by a set of microbial pathogens and herbivorous insects with different modes of attack. Arabidopsis plants were exposed to a pathogenic leaf bacterium (Pseudomonas syringae pv. tomato), a pathogenic leaf fungus (Alternaria brassicicola), tissue-chewing caterpillars (Pieris rapae), cell-content-feeding thrips (Frankliniella occidentalis), or phloem-feeding aphids (Myzus persicae). Monitoring the signal signature in each plant-attacker combination showed that the kinetics of SA, JA, and ET production varies greatly in both quantity and timing. Analysis of global gene expression profiles demonstrated that the signal signature characteristic of each Arabidopsis-attacker combination is orchestrated into a surprisingly complex set of transcriptional alterations in which, in all cases, stress-related genes are overrepresented. Comparison of the transcript profiles revealed that consistent changes induced by pathogens and insects with very different modes of attack can show considerable overlap. Of all consistent changes induced by A. brassicicola, P. rapae, and F. occidentalis, more than 50% were also induced consistently by P. syringae. Notably, although these four attackers all stimulated JA biosynthesis, the majority of the changes in JA-responsive gene expression were attacker-specific. All together our study shows that SA, JA, and ET play a primary role in the orchestration of the plant's defense response, but other regulatory mechanisms, such as pathway cross-talk or additional attacker-induced signals, eventually shape the highly complex attacker-specific defense response.
Signal signature and transcriptome changes of Arabidopsis during pathogen and insect attack.
No sample metadata fields
View SamplesThe mycotoxin deoxynivalenol (DON) is a secondary metabolite from Fusarium species and is frequently present on wheat and other cereals. The main effects of DON are a reduction of the feed intake and reduced weight gain of broilers. At the molecular level DON binds to the 60S ribosomal subunit and inhibits subsequently protein synthesis at the translational level. It has been suggested that cells and tissues with high protein turnover rate, like the liver and small intestine, are most affected by DON. However, little is known about other effects of DON e.g. at the transcriptional level. Therefore we decided to perform a microarray analysis, which allows us the investigation of thousands of transcripts in one experiment.
Fusarium mycotoxin-contaminated wheat containing deoxynivalenol alters the gene expression in the liver and the jejunum of broilers.
Age, Specimen part, Treatment
View SamplesPtf1a was identified as the essential transcription factor which controls pancreatic exocrine enzyme expression. With lineage tracing eperiments Ptf1a was recognized as an important pancreatic progenitor transcription factor and Ptf1a null mice do not develop a pancreas.
RNA profiling and chromatin immunoprecipitation-sequencing reveal that PTF1a stabilizes pancreas progenitor identity via the control of MNX1/HLXB9 and a network of other transcription factors.
Specimen part
View SamplesTime course of early development of peripheral nerve, from embryonic day 9.5 to postnatal day 0.
Efficient isolation and gene expression profiling of small numbers of neural crest stem cells and developing Schwann cells.
No sample metadata fields
View SamplesPrevious in vitro studies in our lab have shown that CD24, a cell surface receptor, actively regulates lipid accumulation in adipocytes. But how CD24 regulates this process remains unknown. In order to answer this question, we initially tested to determine if CD24 regulates lipid accumulation by regulating glucose uptake in adipocytes in vitro. We observed that instead, CD24 caused the dysregulation of the expression of 134 genes as determined by DNA microarray analysis. We then validated the expression of select four genes, when CD24 is knocked down during the different stages of adipogenesis in 3T3-L1 pre-adipocytes in vitro. To further confirm the role of these genes, we then determined the expression patterns of these four genes in primary cells undergoing adipogenesis that were isolated from the epididymal and inguinal white adipose tissue depots of CD24 knockout mice. Surprisingly, we found that these genes were dysregulated in the inguinal but not the epididymal depot in vitro. Overall, the data presented here suggests that CD24 is necessary for select gene expression, but not glucose uptake, during adipogenesis in vitro.
CD24 is required for regulating gene expression, but not glucose uptake, during adipogenesis.
Cell line
View SamplesAims: To map histone modifications with unprecedented resolution both globally and locus-specifically, and to link modification patterns to gene expression. Materials & methods: Using correlations between quantitative mass spectrometry and chromatin immunoprecipitation/microarray analyses, we have mapped histone post-translational modifications in fission yeast (Schizosaccharomyces pombe). Results: Acetylations at lysine 9, 18 and 27 of histone H3 give the best positive correlations with gene expression in this organism. Using clustering analysis and gene ontology search tools, we identified promoter histone modification patterns that characterize several classes of gene function. For example, gene promoters of genes involved in cytokinesis have high H3K36me2 and low H3K4me2, whereas the converse pattern is found ar promoters of gene involved in positive regulation of the cell cycle. We detected acetylation of H4 preferentially at lysine 16 followed by lysine 12, 8 and 5. Our analysis shows that this H4 acetylation bias in the coding regions is dependent upon gene length and linked to gene expression. Our analysis also reveals a role for H3K36 methylation at gene promoters where it functions in a crosstalk between the histone methyltransferase Set2KMT3 and the histone deacetylase Clr6, which removes H3K27ac leading to repression of transcription. Conclusion: Histone modification patterns could be linked to gene expression in fission yeast.
Genome-wide mapping of histone modifications and mass spectrometry reveal H4 acetylation bias and H3K36 methylation at gene promoters in fission yeast.
No sample metadata fields
View SamplesEpidemiological studies provide strong evidence that consumption of cruciferous vegetables, such as broccoli, can significantly reduce the risk of developing cancers. Sulforaphane (SFN), a phytochemical derived from cruciferous vegetables, induces anti-proliferative and pro-apoptotic responses in prostate cancer cells, but not in normal prostate cells. The mechanisms responsible for these specific chemopreventive properties remain unclear. We utilized RNA sequencing to test the hypothesis that SFN modifies the expression of genes that are critical in prostate cancer progression. Normal prostate epithelial cells, and androgen-dependent and androgen-independent prostate cancer cells were treated with 15 µM SFN and the transcriptome was determined at 6 and 24 hour time points. SFN altered the expression of ~3,000 genes in each cell line and the response was highly dynamic over time. SFN influenced the expression of genes in functional groups and pathways that are critical in cancer including cell cycle, apoptosis and angiogenesis, but the specific effects of SFN differed depending on the state of cancer progression. Network analysis suggested that a transcription factor that is overexpressed in many cancers, Specificity protein 1 (Sp1), is a major mediator of SFN-induced changes in gene expression. Nuclear Sp1 protein was significantly decreased by 24 hour SFN treatment in prostate cancer cells, while a related transcription factor, Sp3 protein was only modestly decreased in androgen-independent prostate cancer cells. Overall, the data show that SFN significantly affects gene expression in normal and cancer cells, with key targets in chemopreventive processes, making it a promising dietary anti-cancer agent. Overall design: Examination of how the transcriptome of normal and prostate cancer cells is altered by treatment with sulforaphane
Transcriptome analysis reveals a dynamic and differential transcriptional response to sulforaphane in normal and prostate cancer cells and suggests a role for Sp1 in chemoprevention.
Specimen part, Subject, Time
View SamplesIdentifying the effect of the co-regulator Hic-5 (TGFB1I1) and TGFB on the transcriptional profile of WPMY human prostate fibroblast cells with view to further elucidating the broader biological role of Hic-5 and TGFB on fibroblast.
VDR activity is differentially affected by Hic-5 in prostate cancer and stromal cells.
Specimen part, Cell line, Treatment
View SamplesIdentifying the effect of the co-chaperone SGTA on global androgen receptor transcriptional activity in C4-2B prostate cancer cells with view to further elucidating the broader biological role of SGTA on other signaling pathways within prostate cancer cells
Knockdown of the cochaperone SGTA results in the suppression of androgen and PI3K/Akt signaling and inhibition of prostate cancer cell proliferation.
Specimen part, Treatment
View Samples