Transcription profiling of maize to identify gene expression changes after chilling for 28 hours (acclimation phase)
ABSTRACT: The aim of this study was to identify alarm (fast) and acclimation phase (delayed) changes in the gene expression pattern in leaves of maize (CM 109 genotype) subjected to moderate chilling for 28 hours.
Project description:Mating is a complex process that causes many behavioral and physiological changes, but the factors triggering these changes and the underlying molecular processes are not well characterized. Honey bee queens provide a convenient system for dissecting these factors (e.g., physical manipulation, insemination volume, insemination substance) via instrumental insemination. We examined the effects of carbon dioxide (CO2), a commonly used anesthetic in instrumental insemination that causes changes similar to those observed after mating, and physical manipulation, which presumably mimics the act of copulation, on the brain transcriptional changes in honey bee queens. We found significant gene overlap between our study and previous mating studies in honey bee queens and Drosophila. This suggests that molecular pathways regulating the mating process are conserved across different mating regimes of honey bees as well as across insect orders.
Project description:Identification of the régulation pathways implied in adventitious root formation control in Arabidopsis etiolated seedlings. 2 mutants : a null allele and a weak allele of the ARGONAUTE gene. 4 repetitions in 2 pools for each sample.
Project description:Hypoxia results in the changes in expression of many genes, the majority of which are mediated via the transcriptional activity of the hypoxia inducible factor (HIF) complex. However, other mechanisms of gene regulation by hypoxia are likely and include control of mRNA stability, regulation of mRNA translation and regulation mediated by micrornas. The aim of this study is to identify microRNAs which expression is regulated by hypoxia. We chose the breast cancer line MCF7 for study as we had previously characterised the expression of the components of the HIF system in that cell line and undertaken an extensive study of the gene expression profile in response to hypoxia, a prolyl hydroxylase inhibitor dimethyloxalylglycine and HIF-1a isoform manipulations (Eldvidge. G.P. et al. (2006) JBC, vol. 281, 22, 15215-15226).
Project description:Responses to social cues, such as pheromones, can be modified by genotype, physiology, or environmental context. Honey bee queens produce a pheromone (queen mandibular pheromone; QMP) which regulates many aspects of worker bee behavior and physiology. Forager honey bees are less responsive to QMP than young nurse bees engaged in brood care, suggesting that physiological changes associated with behavioral maturation may modulate response to this pheromone. Since cGMP is a major regulator of behavioral maturation in honey bee workers, we examined its role in modulating worker responses to QMP. Treatment with a cGMP analog, 8-Br-cGMP, resulted in significant reductions in both behavioral and physiological responses to QMP in young caged workers. Treatment significantly reduced attraction to QMP (the retinue response) and inhibited the QMP-mediated increase in vitellogenin levels in the fat bodies of worker bees. Genome-wide analysis of brain gene expression patterns demonstrated that cGMP has a larger effect on expression levels than QMP, and that QMP has specific effects in the presence of cGMP, suggesting that some responses to QMP may be dependent on an individual bees physiological state. Several functional gene categories were significantly differentially expressed, including genes involved in regulating GTPase activity, phototransduction, immunity, and carboxylic acid transmembrane transporter activity. Overall, our data suggest that cGMP-mediated processes play a large role in modulating responses to queen pheromone in honey bees, at the behavioral, physiological and molecular levels.
Project description:IL-1R associated kinase-4 (IRAK4) is a key enzyme required for activation of the common Toll-like Receptor (TLR) signaling cascade, which results in the transcription of inflammatory and immunity genes. IRAK-4 deficiency has recently been described as a rare form of innate immunodeficiency. Patients present with pyogenic bacterial infections and bacteraemia, particularly with Gram+ Streptococcus pneumoniae, and isolated PBMC from these patients fail to produce inflammatory cytokines in response to TLR agonists. We embarked on this study for several purposes: (1) to identify defective gene response resulting from IRAK4-deficiency that are responsible for the patients' susceptibility to infection by particular bacteria (2) to identify genetic responses that confer relatively normal immunity in these patients despite having a defect in such a critical component of the innate immune system (3) to gain understanding of the transcriptional regulation of inflammatory genes (4) to gain insight into TLR signal transduction pathways, in particular, the role of IRAK4 in the TLR2 and TLR4 pathways initiated by Gram+ and Gram- bacterial components respectively. Transcriptional responses to TNF-alpha, IL-1beta, peptidoglycan or lipopolysaccharide (TLR2/4 agonists) were evaluated at 4 hrs in peripheral blood monocytes (PBM) from the patient bearing the IRAK4 Q293X mutation compared to PBM from 5 healthy individuals.
Project description:Persons with Chronic Granulomatous Disease, are susceptible to a narrow range of infections resulting from the failure of cells to generate toxic reactive oxygen species (ROS) required for phagocytice oxidative killing of microorganisms. For unknown reasons, many inflammatory conditions (inflammatory bowel disease, periodontal inflammation, granulomatous obstruction of the urinary and gastrointestinal tract and “sterile” inflammation of the lungs and other organs) are also associated with the disease. The goal of this study is to investigate the role of ROS in the regulation of inflammatory and immunity genes induced by Toll-like Receptors (TLRs). Transcriptional responses to peptidoglycan or lipopolysaccharide (TLR2/4 agonists) were evaluated at 4 and 24 hrs in peripheral blood monocytes (PBM) from three males with CGD compared to PBM from 5 healthy individuals.
Project description:Human bronchial epithelial cells (16HBE14O-) were stimulated with the commensal bacterium S. salivarius K12, or the pathogens S. aureus, P. aeruginosa, or S. enteritidis (subtype Typhimurium) for 1 hour.
Project description:The objective of the study was to discover new functions of chemokine CXCL9/MIG, a cationic chemokine that has antimicrobial properties. Human monocytic cell line, THP-1 cells were stimulated 4 hours with chemokine MIG or CCL2/MCP-1 (a chemokine that is not positively charged and has no antimicrobial activity). By using a 21,000 oligo-based DNA human microarray we analyzed gene expression profiles induced by MIG and by MCP-1. The gene expression profile induced by MIG was >85% different from that induced by MCP-1. MIG increased transcription of genes encoding various chemokines (including CCL3/MIP-1alpha, CCL4/MIP-1beta, CCL2/MCP-1 and CXCL8/IL-8), cytokines (TNF-alpha), indicating that MIG has an immunomodulatory effect on THP-1 cells. Additionally, MIG strongly up-regulated a set of genes identified as having tumor suppressor functions, including BTG2, BTG1, P21, IGFBP3, DSCR1 and genes encoding markers for mature leukocyte differentiation (PLAU, LPL, PLAUR etc). In parallel, MIG down-regulated the expression of oncogenes (MYC), and genes related to cell proliferation and cell cycle progression. This gene profile strongly suggested that the chemokine MIG had anti-proliferative activity and might induce THP-1 cells to undergo terminal differentiation.
Project description:The objective of the study was to evaluate transcriptional response of endotoxin-stimulated human monocytic cells in presence or absence of host defense peptide LL-37 at low physiologically relevant concentrations. Human monocytic cells THP-1 were stimulated with LPS (10ng/ml) in presence or absence of LL-37 (5 ug/ml), as well as with the peptide alone, for 4 hours. The trends of LPS-induced altered gene expression in presence of the peptide were further validated by quantitative real-time PCR.
Project description:This experiment evaluates quick (alarm) response to chilling in chilling-sensitive maize plants.<br>Maize inbred line cm109 were grown in optimal conditions until third leaf was fully developed. <br>At this stage plants were divided into three experimental variants: k0 - control plants, frozen<br>at the beginning of daylight, k4 - control plants kept in the same conditions and frozen after 4 hours<br>since beginning of daylight, c4 - plants kept in 14 deg. C for 4 hours since "dawn". At the mentioned<br>moments, leaves were harvested and frozen in liquid nitrogen for RNA isolation.