ABSTRACT: The MAK-1 pathway is the least characterized MAP kinase pathway in Neurospora. Microarray analyses were carried out to identify genes with altered expression in Δmak-1 as compared to wild type strains. Mycelial mats of wild type and Δmak-1 strains were grown in constant light (LL) at 25C for 2 and 6 days, respectively, in 1X Vogel’s, 2% glucose, 0.5% Arginine HCl, pH 6.0. A cork borer was used to cut plugs to inoculate 75mL of the same liquid media and cultures were grown in LL at 25C for 24h, transferred to constant darkness (DD) 25C for 24 h before being harvested and total RNA extracted. One-condition experiment of the Δmak-1 mutant strain compared to the wild type strain. Cy3 and Cy5 dye swaps were performed.
Project description:Poplar (Populus trichocarpa, clone Nisqually-1) plants were grown in a Conviron PGR 15 growth chamber using precise control of temperature, light, and humidity. Diurnal (driven) conditions included 12L:12D light cycles and 25C/12C thermocycles in three different combinations. These were: photocycles (LDHH), 12 hrs. light (L)/12 hrs. dark (D) at a constant temperature (25C; HH); photo/thermocycles (LDHC): 12 hrs. light (L) /12 hrs. dark (D) with a high day temperature (25C) and a low night temperature (12C); and thermocycles (LLHC): continuous light (LL) with 12 hrs. high/12 hrs. low temperature (25C, day; 12C, night). Light intensity and relative humidity were 700 micromol m-2s-2 and 50%, respectively. Three-month-old poplar plants were entrained for at least one week under the respective condition prior to initiation of each experiment. Leaves and stems from individual poplar plants were collected every four hours for 48 hrs in driven (diurnal) conditions followed by a two day freerun spacer under continuous light/temperature followed by two additional days of sampling under the same continuous free run condition.
Project description:The effect of light during the development of freezing tolerance was studied in winter wheat (Triticum aestivum L. var. Mv Emese) and spring wheat variety Nadro. Ten-day-old plants were cold hardened at 5°C for 12 days either under normal (250 mmol m-2 s-1) or low light (20 mmol m-2 s-1) conditions. Samples of Emese (E) and Nadro (N) plants grown at 18°C under normal (NL) and low (LL) light fluences were compared to each other in a simple loop design and E-NL vs. E-LL; N-NL vs. N-LL; E-NL vs. NLL and E-LL vs. N-LL comparisons were made.
Project description:Chickens divergently selected for either high abdominal fat content (fat genotype) or low abdominal fat content (lean genotype) at Station Recherches Avicoles, Institut National de la Recherche Agronomique Nouzilly, France were used to profile abdominal fat gene expression at 7 weeks of age. The fat line (FL) and lean line (LL) chickens differ in various phenotypic and metabolic measurements, including abdominal fatness, plasma glycemia and triiodothyronine (T3). The FL and LL chickens represent unique models for characterizing biomedical and agricultural traits. Massively parallel RNA sequencing (RNA-Seq) was completed on an Illumina HiSeq 2000 System for transcription analysis of FL and LL abdominal fat. Statistical analysis was completed using CLC Genomics Workbench software. A total of 1,703 genes were differentially expressed in the FL versus LL adipose tissue [FDR<0.05 and fold change (FL/LL) > 1.2]. The differentially expressed genes include metabolic enzymes, acute phase proteins, growth factors, coagulation factors, immune factors, vasoregulators and transcription factors involved in various pathways. Several of the functional genes identified are also positional candidate genes within quantitative trait loci (QTL) in an F2 population created from an intercross of the FL and LL lines. Keywords: Divergently selected chickens, fatness, transcriptional profiling, differentially expressed genes Abdominal fat mRNA profiles of fat line (FL) and lean line (LL) chickens at 7 weeks of age were generated by deep sequencing (on an Illumina HiSeq 2000 system) employing several sequencing schemes to determine depth of coverage from 1, 4, and 8 multiplexed libraries per sequencing lane. Transcriptional analysis was completed by averaging short paired-end sequence reads (101 bp) for each bird across three sequencing depths.
Project description:Aspergillus fumigatus contributes to invasive and allergic pulmonary disease in immunocompromised individuals. The pulmonary mucus of cystic fibrosis (CF) patients displays elevated levels of the pleiotropic cathelicidin antimicrobial peptide LL-37 and the aim of this work was to assess the effect of LL-37 on the growth A. fumigatus. Exposure of A. fumigatus conidia to high concentrations of intact LL-37 (100 μg/ml) for 24 hours had a positive effect on growth (277.45 ± 22.59% (p < 0.01)) whereas scrambled LL-37 (76.45 ± 7.46%) did not. Exposure of 24 hour pre-formed mycelium to 5 μg/ml LL-37 for 48 hours increased hyphal wet weight significantly (4.37 ± 0.23 g, p < 0.001) compared to the control (2.67 ± 0.05 g). Amino acid leakage from mycelium was observed in the presence of LL-37 and gliotoxin secretion was increased at 24 hours from LL-37 exposed hyphae (169.1 ± 6.36 ng/mg hyphae, p < 0.05) compared to the control (102 ± 18.81 ng/mg hyphae). Quantitative proteomic analysis of 24 hour LL-37 treated hyphae revealed an increase in the abundance of proteins associated with growth (eIF-5A (16.3 fold increased), tissue degradation (aspartic endopeptidase (4.7 fold increased)) and allergic reactions (Asp F13 (10 fold increased)). By 48 hours there was an increase in proteins indicative of cellular stress (glutathione peroxidase (9 fold increased)), growth (eIF-5A (6 fold increased), and virulence (ribonuclease mitogillin (3.7 fold increased). These results indicate that LL-37 stimulates A. fumigatus growth and this may result in increased fungal growth and secretion of toxins in the lungs of CF patients.
Project description:Arabidopsis (Arabidopsis thaliana) leaf was exposed to excess light for 30 min and 2 hours or to 24 µM DBMIB for 30 min and 2 hours. Expression levels relative to low light (LL) were determined
Project description:Background: The incidence of alcohol and tobacco co-abuse is as high as 80%. The molecular mechanism underlying this comorbidity is virtually unknown but interactions between these drugs have important implications for the development of, and recovery from drug dependence. Methods: We investigated the effects of chronic tobacco and alcohol abuse and the interaction of the two behaviours on global gene expression in the human nucleus accumbens using cDNA microarrays and 20 alcoholic and control cases, with and without smoking comorbidity. Changes in gene expression were established by two-way ANOVA. Unsupervised hierarchical clustering was utilized to probe the strength of the data sets. Results: Subjecting the data sets derived from microarray gene expression screening to unsupervised hierarchical clustering tied the cases into distinct groups. When considering all alcohol-responsive genes, alcoholics were separated from non alcoholics with the exception of one control case. All smokers were distinguished from non smokers based on similarity in expression of smoking-sensitive genes. In the nucleus accumbens, alcohol-responsive genes were associated with transcription, lipid metabolism and signalling. Smoking-sensitive genes were predominantly assigned to functional groups concerned with RNA processing and the endoplasmic reticulum. Both drugs influenced the expression of genes involved in matrix remodelling, proliferation and cell morphogenesis. Additionally, a gene set encoding proteins involved in the canonical pathway ‘regulation of the actin cytoskeleton’ was induced in response to alcohol and tobacco co-abuse and included. Conclusions: The region-specific modulation of alcohol-sensitive gene expression by smoking may have important consequences for alcohol-induced aberrations within the mesolimbic dopaminergic system. The data set contained individual RNA samples extracted from the nucleus accumbens from 5 non smoking non drinking control case, 5 non smoking alcoholics, 5 non drinking smokers, and 5 smoking alcoholics. An aliquot if each sample was combined to generate a reference pool. Each sample was amplified individually and labelled with Cy3 in the process, the reference samples was amplified and labelled with Cy5. Each sample was hybridised competitively against the reference sample to 1 array.
Project description:To identify the respective roles of light and ROS in the photoinhibition process and detect a possible light-driven tolerance to oxidative stress, we compared the transcriptomic responses of Synechococcus sp. WH7803 acclimated to low (LL) or high light (HL) to oxidative stress, induced by hydrogen peroxide (H202) or methylviologen (MV). Cultures were acclimated during many generations to continuous low light (LL, 18 ?mol photons m-2 s-1, hereafter LL cells) and high light (HL, 250 ?mol photons m-2 s-1, hereafter HL cells) provided by Sylvania Daylight 58W/154 fluorescent bulbs. For all stress experiments performed in this study, exponentially growing cultures (1 to 3 x 107 cells mL-1), were split into subcultures and submitted to oxidative stress by addition of H2O2 or MV and harvested when PSII quantum yield fell to half of the initial value. For H2O2 experiments, this level of PSII photoinactivation was reached 2 h after submitting LL and HL cultures to 750 µM and 25 µM respectively. Because of the large divergence in dose and kinetics responses to MV between LL- and HL cells, it was not possible to find MV concentrations leading to 50 % decrease of quantum yield at the same time for both light acclimations. Thus, array analyses for MV were performed on HL and LL cultures incubated at the same MV concentration (50 µM) but harvested once PSII quantum yield was halved, i.e. after 1 and 3.5 h of stress respectively. All hybridizations were performed on 4 independent biological replicates and using as reference sample a pool of RNA from all samples investigated in this study. Pairwise comparison were performed to analyze the stress induced by either H2O2 or MV on both LL- and HL cultures (i.e. LL-Ct vs. LL+MV, LL-Ct vs. LL+H2O2, HL-Ct vs. HL+MV, HL-Ct vs. HL+H2O2) as well as to compare the steady state acclimation to different light conditions (i.e. LL-Ct vs. HL-Ct).