Project description:The two major methods for growing C. elegans are liquid and plate culture. Differences in oxygenation and other environmental variables could affect many experimentally relevant biological processes, such as metabolism, cellular structure, and gene regulation. Worms on solid support move with deliberate sinusoidal movements, while worms in liquid thrash rapidly and almost constantly, often appearing elongated. We investigated differential gene expression under these two commonly used growth conditions. Embryos were isolated from adults grown on plates. After hatching, animals were placed either on plates or in liquid under standard conditions, and grown until young adulthood, approximately 48 hours later. RNA was isolated independently from each growth, differentially labeled with a fluorescent dye, and mixed directly for comparative hybridization to NimbleGen DNA microarrays, which contained probes designed to measure expression from all predicted C. elegans coding genes. The experiment was performed in triplicate. Analysis of the expression data yielded surprisingly few genes with differential expression, about 1%. Overall, 176 genes were downregulated significantly (p<0.01; Student's t) in liquid culture relative to plates, but of these only 102 genes were down two-fold or more. A total of 121 genes were upregulated (p<0.01. Student's t) in liquid; of these, RNA corresponding to 50 increased by at least two-fold. Surprisingly few genes directly associated with a stress response were differentially regulated in this experiment. However, the single gene most strongly upregulated in liquid is nnt-1, which encodes a mitochondrial NADP transhydrogenase, which protects against oxidative stress (Arkbladt et al., 2005 PMID: 15890626). Other molecules associated with reducing oxidation are also upregulated in liquid culture, including thioredoxin, and two glutathione-S-transferases. As a class, however, the group of genes most differentially regulated encode collagens. A total of 12 collagen genes were downregulated in liquid culture relative to plates, while none are upregulated. Other genes affected include those encoding proteins involved in ubiquitin-mediated proteolysis, Ras signaling, transcriptional regulation, ribosome function, and multiple membrane-associated proteins. The limited changes in relative RNA levels under different culture conditions provide increased confidence in comparisons made between worms grown in liquid and solid culture, and more generally between datasets obtained in different labs under slightly different culture conditions. Knowing which genes are most responsive to different culture conditions inform us about how environment affects the animal, and should be of interest for comparison to other stress and longevity global datasets. Total RNA was extracted from young adult hermaphrodite C. elegans grown either in s-basal liquid cultures or nematode growth medium plates under standard conditions.

Project description:The two major methods for growing C. elegans are liquid and plate culture. Differences in oxygenation and other environmental variables could affect many experimentally relevant biological processes, such as metabolism, cellular structure, and gene regulation. Worms on solid support move with deliberate sinusoidal movements, while worms in liquid thrash rapidly and almost constantly, often appearing elongated. We investigated differential gene expression under these two commonly used growth conditions. Embryos were isolated from adults grown on plates. After hatching, animals were placed either on plates or in liquid under standard conditions, and grown until young adulthood, approximately 48 hours later. RNA was isolated independently from each growth, differentially labeled with a fluorescent dye, and mixed directly for comparative hybridization to NimbleGen DNA microarrays, which contained probes designed to measure expression from all predicted C. elegans coding genes. The experiment was performed in triplicate. Analysis of the expression data yielded surprisingly few genes with differential expression, about 1%. Overall, 176 genes were downregulated significantly (p<0.01; Student's t) in liquid culture relative to plates, but of these only 102 genes were down two-fold or more. A total of 121 genes were upregulated (p<0.01. Student's t) in liquid; of these, RNA corresponding to 50 increased by at least two-fold. Surprisingly few genes directly associated with a stress response were differentially regulated in this experiment. However, the single gene most strongly upregulated in liquid is nnt-1, which encodes a mitochondrial NADP transhydrogenase, which protects against oxidative stress (Arkbladt et al., 2005 PMID: 15890626). Other molecules associated with reducing oxidation are also upregulated in liquid culture, including thioredoxin, and two glutathione-S-transferases. As a class, however, the group of genes most differentially regulated encode collagens. A total of 12 collagen genes were downregulated in liquid culture relative to plates, while none are upregulated. Other genes affected include those encoding proteins involved in ubiquitin-mediated proteolysis, Ras signaling, transcriptional regulation, ribosome function, and multiple membrane-associated proteins. The limited changes in relative RNA levels under different culture conditions provide increased confidence in comparisons made between worms grown in liquid and solid culture, and more generally between datasets obtained in different labs under slightly different culture conditions. Knowing which genes are most responsive to different culture conditions inform us about how environment affects the animal, and should be of interest for comparison to other stress and longevity global datasets.

Project description:Shewanella oneidensis is an important model organism for bioremediation studies because of its diverse respiratory capabilities. In recent years, biofilm development of S. oneidensis has been extensively studied because it is essential to reduce solid metals. As a special form of biofilm, however, pellicles are largely overlooked. The goal of this work was to understand requirements of S. oneidensis pellicle formation and the molecular basis of pellicle formation. We demonstrated that successful pellicle formation and survival was likely to require the threshold level of cell density and higher concentration of oxygen. Proteinase K and EDTA were potent pellicle disrupter. DNA microarray experiments were used to study the gene expression profile of young air–liquid interface pellicle relative to planktonic cells, which indicated that the air–liquid interface pellicle was more metabolically active than the planktonic cells. Most notably, consistently up-regulation of iron or heme uptake and transportation proteins was observed in the S. oneidensis MR-1 pellicle. However, neither the hmuT nor hugA heme transport mutant was defective in pellicle formation. An examination of the influence of several metal cations on the anti-pellicle activity of EDTA showed that Ca (II), Mn(II), Cu(II), and Zn(II) fully protected S. oneidensis MR-1 pellicle against EDTA treatment while additional of iron enabled the initiation of pellicle formation but maturation was significantly impaired. Collectively, iron was less important than other metals with respect to pellicle formation in S. oneidensis. A fresh colony grown overnight on a LB plate was used to inoculate 50 ml LB and incubated in a shaker (200 rpm) to an OD600 of 0.8 at the room temperature. This culture was then diluted 500-fold with fresh LB, resulting in the starting cultures. Aliquots of 30ml starting cultures were transferred to 50-ml Pyrex beakers and allowed to develop pellicles at the room temperature. When a complete but thin (young pellicle) at the interface were formed (about 30h hours), planktonic culture and pellicle were separated and applied to centrifugation at 8000 rpm for 3 min at room temperature. 3 parallel starting cultures were used and 3 samlpes of pellicle cells or planktonic cells were collected at 30h. RNA from the pellicle cells was fluorescently labeled with Cy3, and that from the planktonic was labeled with Cy5.

			Action	DRS
	Andrew_Sue_Ecoli_E10_C1.raw	Raw
	Andrew_Sue_Ecoli_E11_C1.raw	Raw
	Andrew_Sue_Ecoli_E12_C1.raw	Raw
	Andrew_Sue_Ecoli_E16_C1.raw	Raw
	Andrew_Sue_Ecoli_E17_C1.raw	Raw

Dataset Information

Comparison between the proteome of Escherichia coli single colony and during liquid culture

Dataset's files

Publications

Liquid chromatography mass spectrometry-based proteomics of <i>Escherichia coli</i> single colony.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets