Gene expression assessed by microarrays in smoothhead sculpin, sailfin sculpin and Pacific Staghorn sculpin exposed to hypoxia over time
ABSTRACT: Transcriptional responses to hypoxia were assessed in three species of marine fish (smoothhead sculpin [Artedius lateralis], sailfin sculpin [Nautichthys oculafasciatus] and Pacific staghorn sculpin [Leptocottus armatus]) all of which have previously been shown to share the same level of hypoxia tolerance. To determine if there is convergence in mechanisms underlying phenotypic convergence of hypoxia tolerance, each species was exposed to short-term (8 hours) and long-term (72 hours) hypoxia. Specifically, liver was sampled and mRNA was extracted from each species at normoxia, 3hr, 8hr, 24hr, 48hr and 72hr of hypoxia.
Project description:Transcriptional responses to hypoxia were compared between a hypoxia tolerant fish (tidepool sculpin; Oligocottus maculosus) and a hypoxia intolerant fish (silverspotted sculpin; Blepsias cirrhosus). To determine if, and how, transcriptional plasticity is associated with differences in hypoxia tolerance, each species was subjected to a hypoxic time-course and liver was sampled at normoxia, 3hr, 8hr, 24hr, 48hr and 72hr of hypoxia. The hypoxic level for each species was scaled to the species' own tolerance level (relative exposure) in order to elicit similar tissue level hypoxia between the two sculpin species. Each species was also subjected to a single environmental O2 tension (absolute exposure) and sampled at 24 hrs of hypoxia.
Project description:We hypothesize that the culture media collected from macrophages exposed to intermittent hypoxia will induce a greater pro-inflammatory gene profile in naïve cultured macrophages than will culture media collected from macrophages exposed to sustained hypoxia. We will evaluate gene expression using microarray analysis of RNA collected from RAW 264.7 macrophages cultured for 24 hours in DMEM media obtained from 1) cells cultured with intermittent hypoxia (2 minute cycles: 90 seconds at 40 Torr and 30 seconds at 8 Torr), 2) media exposed to intermittent hypoxia, 3) cells cultured with sustained hypoxia (8 Torr), 4) media exposed to sustained hypoxia and 4) standard tissue culture conditions (fresh DMEM media; reference).
Project description:We hypothesize that cultured macrophages directly exposed intermittent hypoxia will have a greater change in expression in genes related to inflammatory response than macrophages exposed to sustained hypoxia. We will evaluate gene expression using microarray analysis of RNA collected from RAW 264.7 macrophages cultured under the following environmental conditions: 1) 4 hours of intermittent hypoxia (2 minute cycles: 90 seconds at 40 Torr and 30 seconds at 8 Torr), 2) 4 hours of sustained hypoxia (8 Torr), and 3 ) standard tissue culture conditions (141 Torr; reference).
Project description:The goals of these studies are to explore the mechanisms that may account for evolutionary divergence of adaptive osmotic physiologies among taxa that occupy different osmotic niches. In a common-garden environment, we track genome expression responses to hyper-osmotic (brackish water) challenge during a time-course of acclimation, and contrast these responses between species. We seek to identify mechanisms that facilitate osmotic acclimation that are evolutionarily conserved between basal and derived physiologies, and also to identify mechanisms that are uniquely derived in alternate osmotic environments.
Project description:The goals of these studies are to explore the mechanisms that enable extreme physiological plasticity and that may account for evolutionary divergence of adaptive osmotic physiologies among taxa that occupy different osmotic niches. In a common-garden environment, we track physiological and genome expression responses to hypo-osmotic (freshwater) challenge during a time-course of acclimation, and contrast these responses within and between species. We seek to identify mechanisms that facilitate osmotic acclimation that are evolutionarily conserved between basal and derived physiologies, and identify mechanisms that are uniquely derived to enable the extreme osmotic plasticity exhibited by F. heteroclitus. Importantly, previous studies using a comparable experimental design have identified physiological changes and genome expression responses that are adaptive for populations of F. heteroclitus that live in fresh water. As such, this enables us to test whether mechanisms of adaptive micro-evolutionary divergence across osmotic gradients within F. heteroclitus are shared with the mechanisms that account for patterns of macro-evolutionary divergence between F. heteroclitus and F. majalis that we identify in this study. That is, are the targets of micro-evolutionary fine-tuning the same or different as the targets of macro-evolutionary divergence across osmotic boundaries? Population comparisons include between populations from Chesapeake Bay (CB), coastal Virginia (VA), and coastal Georgia (GA).
Project description:To examine changes in tyrosine kinase activity in prostate cancer tumors developing resistance to androgen deprivation therapy and to compare these to changes in tyrosine kinase activity occuring in cell lines exposed to oxygen deficiency (hypoxia)
Project description:Transcription profile of Escherichia coli cells in mono-species pure planktonic cultures was compared to that of E. coli cells in E. coli-Stenotrophomonas maltophilia dual-species planktonic cultures E. coli cells were separated from dual-species planktonic cultures before total RNA extraction to eliminate possible cross hybridization from S. maltophilia transcripts. The separation method was developed by combining the use of reagent RNAlater and immuno-magnetic separation. Pure E. coli planktonic cultures were processed with the same separation protocol before RNA extraction. Two condition experiments: E. coli mono-species pure planktonic culture vs E. coli in mixed-species planktonic cultures. Two biological replicates with independently grown and harvested planktonic cultures. Each biological replicate has two technical replicates of hybridization on microarray slides. Each slide has three built-in replicates for each probe.
Project description:In humans and other species, Longlong-term hypoxia (LTH) during pregnancy can lead to intrauterine growth restriction with reduced body/brain weight, dysregulation of cerebral blood flow (CBF), and other problems in humans and rodents. In contrast, sheep appear to undergo relatively successful acclimatization, not demonstrating any of the above-mentioned problems except at extremely high altitude. To identify the signal transduction genetic pathways and those critical molecules, which may be involved in acclimatization to high altitude LTH, we conducted microarray with advanced bioinformatic analysis on carotid arteries (CA) from the normoxic near-term ovine fetus at sea-level and those acclimatized to high altitude for 110+ days during gestation. In response to LTH acclimatization, in fetal CA we identified, mRNA from 38 genes upregulated (> 2 fFold; (P < 0.05) and 9 genes downregulated (> 2-f Fold; (P < 0.05). The major genes with upregulated mRNA were SLC1A3, Insulin-like growth factor (IGF) binding protein 3, IGF type 2 receptor, transforming growth factor (TGF) Beta-3, and genes involved in the AKT and BCL2 signal transduction networks. The majority of genes with upregulated mRNA have a common motif for Pbx/Knotted homeobox in the promoter region, and Sox family binding sites in the 3’ un -translated region (UTR). Genes with downregulated mRNA included those involved in the P53 pathway and 5-lipoxygenase activating proteins. The promoter region of all genes with downregulated mRNA, had a common 49 bp region, with a binding site for DOT6 and TOD6, components of the RPD3 histone deacetylase complex RPD3C(L). We also identified miRNA complementary to a number of the altered genes. Thus, the present study identified molecules in the ovine fetus, which may help it to play a role in the acclimatizatione successfully response to high-altitude associated LTH. In these series of experiments we examined changes in gene expression in sheep carotids. Pregnant sheep and non-pregnant adult sheep were exposed to 110 days of hypoxia at 3801 meters of altitude. Carotid arteries from fetuses from non-pregnant adult from sea-level controls and those from high-altitude were compared by Agilent ovine custom array
Project description:Transcription profile of Escherichia coli cells in mono-species pure biofilms was compared to that of E. coli cells in E. coli-Stenotrophomonas maltophilia dual-species biofilms. E. coli cells were separated from dual-species biofilms before total RNA extraction to eliminate possible cross hybridization from S. maltophilia transcripts. The separation method was developed by combining the use of reagent RNAlater and immuno-magnetic separation. Pure E. coli biofilms were processed with the same separation protocol before RNA extraction. Two condition experiments: E. coli mono-species biofilm vs E. coli in mixed-species biofilm. Two biological replicates with independently grown and harvested biofilms. Each biological replicate has two or three technical replicates of hybridization on microarray slides. Each slide has three built-in replicates for each probe.
Project description:Hypoxia imposes stress on filamentous fungi that require oxygen to proliferate. Global transcription analysis of Aspergillus oryzae grown under hypoxic conditions found that the expression of about 50% of 4,244 affected genes was either induced or repressed more than 2-fold. A comparison of these genes with the hypoxically-regulated genes of A. nidulans (Masuo et al., Mol. Gen. Genet. 2010, 284:415-424) based on their predicted amino acid sequences classified them as bi-directional best hit (BBH), one-way best hit (extra homolog: EH) and no-hit (non-syntenic genes: NSG) genes. Clustering analysis of the BBH genes indicated that A. oryzae and A. nidulans down-regulated global translation and transcription under hypoxic conditions, respectively. Under hypoxic conditions, both fungi up-regulated genes for alcohol fermentation and the γ-aminobutyrate shunt of the tricarboxylate cycle, whereas A. oryzae up-regulated the glyoxylate pathway, indicating that both fungi eliminate NADH accumulation under hypoxic conditions. The A. oryzae NS genes included specific genes for secondary and nitric oxide metabolism under hypoxic conditions. This comparative transcriptomic analysis discovered common and strain-specific responses to hypoxia in hypoxic Aspergillus species. We transferred A. oryzae cells from normoxic to hypoxic conditions for 6 h, and then back to normoxic conditions to examine the effect of hypoxia on gene expression. Total RNA was prepared for DNA microarray analysis from the cells after 1, 3, and 6 h of exposure to hypoxia, followed by 1, 3, and 6 h of reoxygenation.