Gray leaf spot (GLS) disease of maize can be caused by either of two sibling fungal species Cercospora zeina or Cercospora zeae-maydis. These species differ in geographical distribution, for example to date only C. zeina is associated with GLS in African countries, such as South Africa. Maize inbred line B73, which is susceptible to GLS, was planted in the field, and subjected to natural infection with C. zeina. Samples were collected from lower leaves with substantial GLS lesions and younger upper leaves of the same plants with very few immature GLS lesions. The first aim of the experiment was to determine which maize genes are induced in response to C. zeina infection. The second aim was to identify C. zeina genes expressed in planta during a compatible interaction. The third aim was to determine whether the C. zeina cercosporin biosynthetic (CTB) genes are expressed in planta. C. zeina fails to produce cercosporin in vitro in contrast to C. zeae-maydis. Cercosporin is a phytotoxin that is thought to play a role in pathogenicity of several Cercospora spp., however its role in the pathogenicity strategy of C. zeina is currently under investigation. Overall design: To collect material that reflected a difference between C. zeina infected B73 leaves and control B73 leaf material, samples were collected from two lower GLS infected leaves (second and third leaf internode below ear), and two upper leaves with minimal GLS symptoms (second and third internode above ear), respectively. The two lower leaves from each plant were pooled prior to RNA extraction, and the two upper leaves from each plant were pooled prior to RNA extraction. Upper and lower leaf samples from three maize B73 plants were subjected to RNA sequencing individually. The three maize plants were selected randomly as one plant per row from three rows of ten B73 plants each.
Complementation of CTB7 in the Maize Pathogen Cercospora zeina Overcomes the Lack of In Vitro Cercosporin Production.
Specimen part, Subject
View SamplesMalaria infection triggers vigorous host immune responses; however, the parasite ligands, host receptors and the signaling pathways responsible for these reactions remain unknown or controversial. Malaria parasites primarily reside within red blood cells (RBCs), thereby hiding themselves from direct contact and recognition by host immune cells. Host responses to malaria infection are very different from those elicited by bacterial and viral infections and the host receptors recognizing parasite ligands have been elusive. Here we investigated mouse genome-wide transcriptional responses to infections with two strains of Plasmodium yoelii (N67 and N67C) and discovered differences in innate response pathways corresponding to strain-specific disease phenotypes. Using in vitro RNAi gene knockdown and knockout mice, we demonstrated that a strong IFN-I response triggered by RNA Polymerase III and melanoma differentiation-associated protein 5 (MDA5), not Toll-like receptors (TLRs), binding of parasite DNA/RNA contributed to a decline of parasitemia in N67-infected mice. We showed that conventional dendritic cells were the major sources of early IFN-I, and that surface expression of phosphatidylserine (PS) on infected RBC (iRBC) might promote their phagocytic uptake, leading to the release of parasite ligands and the IFN-I response in N67 infection. In contrast, an elevated inflammatory response mediated by CD14/TLR and p38 signaling played a role in disease severity and early host death in N67C-infected mice. In addition to identifying cytosolic DNA/RNA sensors and signaling pathways previously unrecognized in malaria infection, our study demonstrates the importance of parasite genetic backgrounds in malaria pathology and provides important information for studying human malaria pathogenesis.
Strain-specific innate immune signaling pathways determine malaria parasitemia dynamics and host mortality.
Sex, Specimen part
View SamplesBackground: Maize plants developed typical gray leaf spot disease (GLS) symptoms initiating at the lower leaves and progressing to upper leaves through the season. Leaf material was collected at 77 days after planting, at which stage there were a large number of GLS disease necrotic lesions on lower leaves (8% surface area on average determined by digital image analysis), but very few lesions and only at chlorotic stage on leaves above the ear (average of 0.2% lesion surface area). Method:To collect material that reflected a difference between C.zeina infected B73 leaves and control B73 leaf material, samples were collected from two lower GLS infected leaves (second and third leaf internode below ear) , and two upper leaves with minimal GLS symptoms (second and third internode above ear), respectively. The two lower leaves from each plant were pooled prior to RNA extraction, and the two upper leaves from each plant were pooled prior to RNA extraction. Upper and lower leaf samples from three maize B73 plants were subjected to RNA sequencing individually. The three maize plants were selected randomly as one plant per row from three rows of ten B73 plants each. Result: A systems genetics strategy revealed regions on the maize genome underlying co-expression of genes in susceptible and resistance responses, including a set of 100 genes common to the susceptible response of sub-tropical and temperate maize. Overall design: To collect material that reflected a difference between C.zeina infected B73 leaves and control B73 leaf material, samples were collected from two lower GLS infected leaves (second and third leaf internode below ear) , and two upper leaves with minimal GLS symptoms (second and third internode above ear), respectively. The two lower leaves from each plant were pooled prior to RNA extraction, and the two upper leaves from each plant were pooled prior to RNA extraction. Upper and lower leaf samples from three maize B73 plants were subjected to RNA sequencing individually. The three maize plants were selected randomly as one plant per row from three rows of ten B73 plants each.
Systems genetics reveals a transcriptional network associated with susceptibility in the maize-grey leaf spot pathosystem.
Subject
View SamplesAffymetrix microarray data was generated from MCF7 breast cancer cells treated in vitro with siRNAs against 78 transcription factors and signalling molecules.
Cell cycle gene networks are associated with melanoma prognosis.
Cell line
View SamplesAffymetrix microarray data were generated from A375 melanoma cells treated in vitro with siRNAs against 45 transcription factors and signalling molecules.
Cell cycle gene networks are associated with melanoma prognosis.
Cell line
View SamplesTo understand the fruit changes and mechanisms involved in the compatible grapevine-virus interaction, we analyzed the berry transcriptome in two stages of development (veraison and ripening) in the red wine cultivar Cabernet Sauvignon infected with Grapevine leaf-roll-associated virus-3 (GLRaV-3). Analysis of global gene expression patterns indicate incomplete berry maturation in infected berries as compared to uninfected fruit suggesting viral infection interrupts the normal berry maturation process.
Compatible GLRaV-3 viral infections affect berry ripening decreasing sugar accumulation and anthocyanin biosynthesis in Vitis vinifera.
Age, Specimen part
View SamplesThe intestine is composed of an epithelial layer, containing rapidly proliferating cells that mature into two distinct anatomic regions, the small and the large intestine. Although previous studies have identified stem cells as the cell-of-origin for the whole intestine, no studies have compared stem cells derived from the small and large intestine. Here, we report intrinsic differences between these two populations of cells. Primary epithelial cells isolated from human fetal small and large intestine and expanded with Wnt agonist, R-spondin 2, displayed differential expression of stem cell markers and separate hierarchical clustering of gene expression involved in differentiation, proliferation and disease pathways. Using a three-dimensional in vitro differentiation assay, single cells derived from small and large intestine formed distinct organoid architecture with cellular hierarchy similar to that found in primary tissue. Our characterization of human fetal intestinal stem cells defies the classical definition proposed by most where small and large intestine are repopulated by an identical epithelial stem cell and raises the question of the importance of intrinsic and extrinsic cues in the development of intestinal diseases.
Distinct human stem cell populations in small and large intestine.
Specimen part
View SamplesRecent studies have identified intracellular metabolism as a fundamental determinant of macrophage function. In obesity, proinflammatory macrophages accumulate in adipose tissue and trigger chronic low-grade inflammation, that promotes the development of systemic insulin resistance, yet changes in their intracellular energy metabolism are currently unknown. We therefore set out to study metabolic signatures of adipose tissue macrophages (ATMs) in lean and obese conditions. F4/80-positive ATMs were isolated from obese vs lean mice. High-fat feeding of wild-type mice and myeloid-specific Hif1-/- mice was used to examine the role of hypoxia-inducible factor-1 (HIF-1) in ATMs part of obese adipose tissue. In vitro, bone marrow-derived macrophages were co-cultured with adipose tissue explants to examine adipose tissue-induced changes in macrophage phenotypes. Transcriptome analysis, real-time flux measurements, ELISA and several other approaches were used to determine the metabolic signatures and inflammatory status of macrophages. In addition, various metabolic routes were inhibited to determine their relevance for cytokine production. Transcriptome analysis and extracellular flux measurements of mouse ATMs revealed unique metabolic rewiring in obesity characterised by both increased glycolysis and oxidative phosphorylation. Similar metabolic activation of CD14+ cells in obese individuals was associated with diabetes outcome. These changes were not observed in peritoneal macrophages from obese vs lean mice and did not resemble metabolic rewiring in M1-primed macrophages. Instead, metabolic activation of macrophages was dose-dependently induced by a set of adipose tissue-derived factors that could not be reduced to leptin or lactate. Using metabolic inhibitors, we identified various metabolic routes, including fatty acid oxidation, glycolysis and glutaminolysis, that contributed to cytokine release by ATMs in lean adipose tissue. Glycolysis appeared to be the main contributor to the proinflammatory trait of macrophages in obese adipose tissue. HIF-1, a key regulator of glycolysis, nonetheless appeared to play no critical role in proinflammatory activation of ATMs during early stages of obesity. Our results reveal unique metabolic activation of ATMs in obesity that promotes inflammatory cytokine release. Further understanding of metabolic programming in ATMs will most likely lead to novel therapeutic targets to curtail inflammatory responses in obesity.
Unique metabolic activation of adipose tissue macrophages in obesity promotes inflammatory responses.
Sex, Specimen part
View SamplesOverexpression of a grapevine C-repeat binding factor (CBF) gene, VvCBF4 in cv. Freedom was found to improve freezing survival in non-cold-acclimated vines.
The Vitis vinifera C-repeat binding protein 4 (VvCBF4) transcriptional factor enhances freezing tolerance in wine grape.
Specimen part
View SamplesTo elucidate the effect of heat stress and the following recovery on grapevines and identify some regulated genes representing the classical heat stress response and thermotolerance mechanisms, transcript abundance of grapevine (Vitis vinifera L.) were quantified using the Affymetrix Grape Genome oligonucleotide microarray (15,700 transcripts), followed by quantitive Real-Time PCR validation for some transcript profiles. The treatment: heat stress(5h) and the following recovery (18.5h), sampling were conducted at two time respectively. ****[PLEXdb(http://www.plexdb.org) has submitted this series at GEO on behalf of the original contributor, Lijun Wang. The equivalent experiment is VV40 at PLEXdb.]
Transcriptomic analysis of grape (Vitis vinifera L.) leaves during and after recovery from heat stress.
Specimen part
View Samples