Project description:Gene expression profiling of corals exposed to control (ambient seawater) or 50 ppb copper for 24 hours Two-condition experiment, Control vs 50ppb. Biological replicates: 5 genotypes paired in control vs 50ppb, each genotype collected from different location on reef. One replicate per array.
Project description:On August 22 – 25, 2017, 3 colonies of Montipora capitata with a diameter of ~ 24 cm were collected from the inner lagoon surrounding the Hawaii Institute of Marine Biology (HIMB). The corals were acclimated in outdoor flow-through tanks at HIMB that were supplied with ambient seawater and covered with shade-cloth to mimic PAR levels on the reef. Each colony was split in half with a hammer and chisel to produce two colonies of identical genotype, so that each genotype would experience both ambient and increased temperatures. On August 28 - 29, the corals were equally divided among the experimental tanks, at ambient (n=3) or increased (n=3) temperature. Throughout the temperature treatment, corals were randomly rotated among tanks to minimize potential tank effects. On September 1, the temperature in the increased temperature tanks was turned up 2°C per day, 1°C at 0900 and 1°C at 1400, for four days, reaching an average temperature of 30 °C. The ambient tanks averaged 25 °C. On September 26, the heaters were turned off and the temperature returned to ambient levels by Sept. 29.
Project description:The study of macroalgae capacity to acclimate and recover in environments contaminated with Cu and Cd could prove a promising way to understand the tolerance mechanisms of these seaweeds against different pollutants. This study used as a model organism Gracilaria tenuistipitata (Rhodophyta), a macroalga with economic and ecological importance. The partial transcriptome of G. tenuistipitata was profiled using cDNA microarrays in the sixth day of exposition to EC50 metals. Genes involved in Cu and Cd chronic stress belonging to various functional categories suffered shallow modifications. This possibly indicates that G. tenuistipitata would be in the acclimatization process. In addition, the expression of nine stress genes accompanied by analysis of the photosynthetic rate of seaweed to both metals in three different time frames was analyzed. Genetic variation linked to the mechanism of resistance of the algae, determined from EC50 culture conditions established for two metals, occurred in the early hours of treatment. It was found that G. tenuistipitata was able to accumulate these two metals and to resist and acclimate to the negative effects produced by these elements. The temporal analysis from the nine specific genes showed some specific transcriptional responses of the G. tenuistipitata, exposed to Cu and Cd. Three-condition experiment, control cells cultivated in seawater enriched with von Stosch solution vs. copper and cadmium (indepedent) treated cells. Biological replicates: 4 control, 2 copper treated, 2 cadmium treated. All independently grown and harvested. Four replicates per array.
Project description:To identify genes which are differentially expressed in Corynebacterium glutamicum in the absence of copper, we performed DNA microarray analyses of cells cultivated under copper starvation conditions compared to copper sufficiency.
Project description:Copper-limiting growth conditions were thought to cause an induction of genes possibly involved in copper uptake and sorting. This rationale in mind, we performed microarray analyses on B. japonicum cells grown in three variations of the BVM minimal medium. Variant 1 contained 2 μM CuSO4 (copper excess). Variant 2 was prepared in HCl-treated glassware without any copper added (copper starvation). The residual copper concentration in this copper-starvation medium was analyzed by GF-AAS and determined to be 5 nM. Variant 3 (extreme copper limitation) was prepared like variant 2 but with the addition of 10 μM BCS and 1 mM ascorbic acid where BCS chelates Cu(I) selectively, and ascorbic acid reduces any Cu(II) to Cu(I). Changes in the transcription profiles were recorded by the pairwise comparison of cells grown in variant 2 vs. 1, and variant 3 vs. 2. Only a small set of genes were differentially up- or down-regulated when copper-starved cells were compared with cells grown in copper excess. Most notably, five genes located adjacent to each other on the B. japonicum genome displayed an increased expression: bll4882 to bll4878. The five genes were named pcuA, pcuB, pcuC, pcuD, and pcuE (mnemonic of proteins for Cu trafficking). The genes with decreased expression are either of unknown function or – not surprisingly – play a role in copper resistance. Extreme copper limitation (variant 3 vs. 2) did not further enhance the expression of the five pcu genes. Instead, another cluster of adjacent genes was strongly up-regulated: bll0889 to bll0883, which code for unidentified transport functions. Incidentally, the list also includes the copper chaperone ScoI. Taken together, copper-limiting growth conditions have led to the de-repression of genes potentially involved in copper acquisition.
Project description:Copper and iron are essential micronutrients for most living organisms because they participate as cofactors in biological processes including respiration, photosynthesis and oxidative stress protection. In many eukaryotic organisms, including yeast and mammals, copper and iron homeostases are highly interconnected; however such interdependence is not well established in higher plants. Here we propose that COPT2, a high-affinity copper transport protein, functions under copper and iron deficiencies in Arabidopsis thaliana. COPT2 is a plasma membrane protein that functions in copper acquisition and distribution. Characterization of the COPT2 expression pattern indicates a synergic response to copper and iron limitation in roots. We have characterized a knockout of COPT2, copt2-1, that leads to increased resistance to simultaneous copper and iron deficiencies, measured as reduced leaf chlorosis and improved maintenance of the photosynthetic apparatus. We propose that COPT2 expression could play a dual role under Fe deficiency. First, COPT2 participates in the attenuation of copper deficiency responses driven by iron limitation maybe aimed to minimize further iron consume. On the other hand, global expression analyses of copt2-1 mutants versus wild type Arabidopsis plants indicate that low phosphate responses are increased in copt2-1 plants. In this sense, COPT2 function under Fe deficiency counteracts low phosphate responses. These results open up new biotechnological approaches to fight iron deficiency in crops.
Project description:Transcriptional analysis of the effects of natural environmental variation across the vertical distribution of Mytilus californianus within a single mussel bed Keywords: Environmental Response 30 Biological replicates from plots sampled at 3 different verticle tide heights above the MLLW at Strawberry Hill Oregon. 15 mussels were sampled after a mid-day emmersion event and 15 mussels were sampled after a 1 hour recovery at ambient seawater temperatures. 1 replicate per array, compared using a common reference sample. 50 Biological replicates for 5 plots sampled at 2 different verticle tide heights above the MLLW at Boiler Bay Oregon. 25 mussels were sampled after a mid-day emmersion event and 25 mussels were sampled after a 1 hour recovery at ambient seawater temperatures. Pooled RNA from 5 biological replicates from each plot per array, compared using a common reference sample.
Project description:Copper-limiting growth conditions were thought to cause an induction of genes possibly involved in copper uptake and sorting. This rationale in mind, we performed microarray analyses on B. japonicum cells grown in three variations of the BVM minimal medium. Variant 1 contained 2 M-NM-<M CuSO4 (copper excess). Variant 2 was prepared in HCl-treated glassware without any copper added (copper starvation). The residual copper concentration in this copper-starvation medium was analyzed by GF-AAS and determined to be 5 nM. Variant 3 (extreme copper limitation) was prepared like variant 2 but with the addition of 10 M-NM-<M BCS and 1 mM ascorbic acid where BCS chelates Cu(I) selectively, and ascorbic acid reduces any Cu(II) to Cu(I). Changes in the transcription profiles were recorded by the pairwise comparison of cells grown in variant 2 vs. 1, and variant 3 vs. 2. Only a small set of genes were differentially up- or down-regulated when copper-starved cells were compared with cells grown in copper excess. Most notably, five genes located adjacent to each other on the B. japonicum genome displayed an increased expression: bll4882 to bll4878. The five genes were named pcuA, pcuB, pcuC, pcuD, and pcuE (mnemonic of proteins for Cu trafficking). The genes with decreased expression are either of unknown function or M-bM-^@M-^S not surprisingly M-bM-^@M-^S play a role in copper resistance. Extreme copper limitation (variant 3 vs. 2) did not further enhance the expression of the five pcu genes. Instead, another cluster of adjacent genes was strongly up-regulated: bll0889 to bll0883, which code for unidentified transport functions. Incidentally, the list also includes the copper chaperone ScoI. Taken together, copper-limiting growth conditions have led to the de-repression of genes potentially involved in copper acquisition. Microarray-based transcriptome analysis of B. japonicum 110spc4 wild-type cells grown under normal, copper-limiting and copper excess conditions