Ustilago maydis is a basidiomycete fungus that causes smut disease in maize. Most prominent symptoms of the disease are plant tumors, which can be induced by U. maydis on all aerial parts of the plant. We identified two linked genes, pit1 and pit2, which are specifically expressed during plant colonization. Deletion mutants for either pit1 or pit2 are unable to induce tumor development and elicit plant defense responses.
Two linked genes encoding a secreted effector and a membrane protein are essential for Ustilago maydis-induced tumour formation.
Specimen part, Disease, Disease stage
View SamplesAnthocyanin induction in plant is considered a general defense response against biotic and abiotic stresses. The infection by Ustilago maydis, the corn smut pathogen, is accompanied with anthocyanin induction in leaf tissue. We revealed that anthocyanin is intentionally induced by the virulence promoting secreted effector protein Tin2. Tin2 protein functions inside plant cells where it interacts with cytoplasmic maize protein kinase ZmTTK1. Tin2 masks an ubiquitin-proteasome degradation motif in ZmTTK1 leading to a more stable active kinase. Active ZmTTK1 controls transcriptional activation of genes in the anthocyanin biosynthesis pathway rerouting phenylalanine away from lignin biosynthesis.
A secreted Ustilago maydis effector promotes virulence by targeting anthocyanin biosynthesis in maize.
Specimen part
View SamplesMany of the genes coding for secreted protein effectors are arranged in gene clusters in the genome of the biotrophic plant pathogen Ustilago maydis. The largest of these gene clusters, cluster 19A, encodes 24 secreted effectors. Deletion of the entire cluster results in severe attenuation of virulence. The generation and analysis strains carrying sub-deletions identified 9 genes significantly contributing to tumor formation after seedling infection. As the individual contributions of these genes to tumor formation were small, we studied the response of maize plants to the whole cluster mutant as well as to several individual mutants by array analysis. This revealed distinct plant responses, demonstrating that the respective effectors have discrete plant targets. Many of the genes coding for secreted protein effectors are arranged in gene clusters in the genome of the biotrophic plant pathogen Ustilago maydis. The largest of these gene clusters, cluster 19A, encodes 24 secreted effectors. Deletion of the entire cluster results in severe attenuation of virulence. The generation and analysis strains carrying sub-deletions identified 9 genes significantly contributing to tumor formation after seedling infection. As the individual contributions of these genes to tumor formation were small, we studied the response of maize plants to the whole cluster mutant as well as to several individual mutants by array analysis. This revealed distinct plant responses, demonstrating that the respective effectors have discrete plant targets.
Characterization of the largest effector gene cluster of Ustilago maydis.
Specimen part, Treatment
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 SamplesThe basidiomycete Ustilago maydis causes smut disease in maize. Colonization of the host plant is initiated by direct penetration of cuticle and cell wall of maize epidermis cells. The invading hyphae are surrounded by the plant plasma membrane and proliferate within the plant tissue. We identified a novel secreted protein, termed Pep1. Disruption mutants of pep1 are not affected in saprophytic growth and develop normal infection structures. However, pep1 mutants fail to penetrate the epidermal cell wall and elicit a strong plant defense response. Using Affymetrix maize arrays we identified about 110 plant genes which are differentially regulated in pep1 and wild type infections during the penetration stage.
Pep1, a secreted effector protein of Ustilago maydis, is required for successful invasion of plant cells.
No sample metadata fields
View SamplesThe hemibiotrophic fungal pathogen Colletotrichum graminicola is the causal agent of anthracnose disease on maize stalks and leaves. After the formation of appressoria the host cell wall is penetrated by the conversion of appressorial turgor pressure into forceful ejection of a penetration peg. Subsequently, C. graminicola establishes biotrophic hyphae in the penetrated epidermis cell at around 36 hours post inoculation (hpi) until a switch of hyphal morphology and lifestyle takes place during the colonization of neighboring host cells at around 72 hpi. During the ensuing necrotrophic growth, dark necrotic lesions are formed that are visible as anthracnose symptoms. We used microarrays to detail the global programme of gene expression during the infection process of Colletotrichum graminicola in its host plant to get insight into the defense response of this compatible interaction and into the metabolic reprogramming needed to supply the fungus with nutrients.
Common Motifs in the Response of Cereal Primary Metabolism to Fungal Pathogens are not Based on Similar Transcriptional Reprogramming.
Time
View SamplesIn this study, a genetically repressed VEGF mouse model was used to analyze uterus transcriptome at G2.5 (gestation day 2.5) by Solexa/ Illumina’s digital gene expression (DGE) system. 831 uterus-specific and 2398 VEGF regulated genes were identified. Gene ontology analysis indicated that genes actively involved in uterus development were members of collagen biosynthesis, cell proliferation and cell apoptosis. Uterus-specific genes were enriched in activities of phosphatidyl inositol phosphate kinase, histone H3-K36 demethylation and protein acetylation. Among VEGF regulated genes, up-regulated genes were associated with RNA polymerase III activity while down-regulated genes were strongly associated with muscle development.Comparable numbers of antisense RNA transcripts were also identified. Expression levels of the antisense RNAs were found tightly correlated with their sense expression levels, an indication of possibly non-specific transcripts generated around the active promoters and enhancers. The antisense RNAs with exceptionally high or low expression levels and the antisense RNAs under VEGF regulation were also identified. These transcripts may be important candidates in regulation of uterus development. This study provides a global survey on genes and antisense transcripts regulated by VEGF in the pre-implantation stage. Results will contribute to the further studies of candidate genes and pathways in regulating implantation process and related diseases. Overall design: Uteri mRNA profiles of G2.5 VEGF-normal (Dox+) and VEGF-repression (Dox-) were generated by Solexa/ Illumina’s digital gene expression (DGE) system.
Transcriptional profiling of mouse uterus at pre-implantation stage under VEGF repression.
Specimen part, Cell line, Subject
View SamplesCutaneous lupus erythematosus (CLE) is a disfiguring disease that can exist as an independent entity or as a manifestation of systemic lupus erythematosus (SLE) where up to 70% of patients experience lesions during their disease course. Subacute CLE (sCLE) is an inflammatory lesion with associated erythema in papulosquamous or annular formations. Typically, sCLE does not scar but depigmentation can occur. Importantly, sCLE is associated with a higher progression to SLE. Discoid lesions (DLE) are often circular and frequently lead to alopecia and scar formation. sCLE lesions have a higher propensity for photoprovocation and a more robust inflammatory infiltrate following ultraviolet (UV) B exposure. The pathogenic mechanisms which govern the differences between DLE and sCLE remain poorly defined, and this is reflected by the refractory nature of cutaneous lesions to usual lupus therapies. In this study, we evaluated the transcriptional profiles of 26 DLE and 23 sCLE biopsies and compared them to control skin and to each other in order to develop a comprehensive understanding of the similarities and differences between these two clinical subtypes.
Enhanced Inflammasome Activity in Systemic Lupus Erythematosus Is Mediated via Type I Interferon-Induced Up-Regulation of Interferon Regulatory Factor 1.
Specimen part, Disease, Disease stage
View SamplesPurpose: The ability of adult zebrafish tissues to undergo dedifferentiation provides an opportunity to probe the molecular underpinnings of cell identity and reprogramming. Zebafish muscle regeneration utilizes dedifferentiation to reprogram mature multinucleated myocytes into dedifferentiated myoblast that re-enter the cell cycle. A unique advantage of this system is that the regenerating cell mass is large and fairly homogenous, facilitating genomics approaches to uncovering the underlying biology. Methods: To better understand cellular reprogramming of mature myocytes, we temporally analyzed the changing transcriptome leading up to the proliferative switch. RNA was obtained after Laser Micro-dissection (LMD) of Control, 9 hour post-injury (HPI) or 18 HPI using Trizol and micro column purification. Illumina''s TruSeq Stranded mRNA Library Prep Kit and 0.1 - 4 µg total mRNA from pooled purified RNA samples were used for performing ribosomal-depletion (Ribo-Zero Gold rRNA Removal Kit, Illumina) and library preparation. Sequencing was performed by the UM DNA Sequencing Core, using an Illumina Hi-Seq 2000 (50-cycle, single end read) platform. Results: Clustering and functional annotation of differentially expressed genes highlighted the importance of catabolic and phagocytic processes upregulation at 9 and 18 hours post injury (hpi). Furthermore, genes encoding principle regulators of chromatin states were actively re-regulated during the reprogramming process. Utilizing the accessibility of these tissues in the zebrafish model, kKnockdown experiments enabled in vivo validation and phenotypic analysis of candidate genes and pathways for their roles in genomic and cellular reprogramming. Additionally, we found that despite of their low expression levels, lncRNAs were highly represented in gene clusters with dynamic, “switch-like” expression profiles, and that miRNA processing was also found important for reprogramming Conclusions: We conclude that reprogramming of a “post-mitotic” myocyte into a dedifferentiated myoblast requires both heritable yet nuanced epigenetic alterations and molecular switches that involve transcription factors, miRNA and lncRNA, while maintaining the lineage restriction of the cell of origin. Overall design: Early time points post injury (9 & 18 hours) mRNA and lncRNA profiles of Zebrafish lateral eye muscle (EOM) were generated by deep sequencing, in quadruplicate, using Illumina Hi-seq.
Temporally distinct transcriptional regulation of myocyte dedifferentiation and Myofiber growth during muscle regeneration.
No sample metadata fields
View SamplesPcG protein complex PRC2 is a methyltransferase specific for histone H3 lysine27, and H3K27me3 is essential for stable transcription silencing. Less well known but quantitatively much more important is the genome-wide role of PRC2 that dimethylates ~70% of total H3K27. Here we show that H3K27me2 occurs in inverse proportion to transcriptional activity in genes and intergenic regions and its loss results in global transcriptional derepression proportionally greatest in previously silent or weakly transcribed regions. H3K27me2 levels are controlled by opposing roaming activities of PRC2 and the H3K27 demethylase dUTX. Unexpectedly, we find an equally pervasive distribution of histone H2A ubiquitylated at lysine 118 (H2AK118ub), attributed to the RING1 subunit of PRC1-type complexes. Overall design: Examination of global changes in transcription genome-wide when E(z) is inactivated by monitoring total RNA from E(z) temperature-sensitive cells at 25°C and 31°C in duplicate
Genome-wide activities of Polycomb complexes control pervasive transcription.
Cell line, Subject
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