Project description:Changes in gene expression are thought to be required for maintaining tissue's proper function under cold stress, but little is known about the role of each tissue in setting the cold tolerance ability in fish. Oreochromis niloticus and Danio rerio are two tropical fishes; they differ in their abilities of cold tolerance. In this study, both fishes were exposed to graded cold temperatures, ranging from 28°C to 18°C and 10°C, and the transcriptomes of 8 tissues at each tempeature were sequenced and compared. By characterizing tissue-based gene expression variation between the two fishes we identified some key tissue specific biological processes, which provide a better understating of the typical biological functions of tissues in physiological fitness under cold stress.
Project description:In this study we used the Affymetrix Barley 1 GeneChip to investigate transcriptome responses of barley cv. Morex to low temperature, including triplicated measurements of cold, freeze/thaw cycles and de-acclimation over 33 days. Experiment Overall Design: Plants were grown at 20ºC for seven days and subject to a symmetrical cycle of acclimation, cold, freeze-thaw, and deacclimation. Chilling began by decreasing the temperature overnight from 20ºC to 4ºC at a rate of 1.3ºCâ¢h-1 and maintaining temperatures of 4 ºC in the day and 2ºC at night for 5 days. Freeze-thaw cycling lasted 12 days with day temperatures of 4ºC and night temperatures gradually decreasing from -2ºC the first night to -4ºC for three nights and -10ºC for four nights, then recovering to -4ºC for three nights and -2ºC for one night. This treatment was designed to allow daily freeze-thaw cycling and protein synthesis. Chilling conditions (4ºC day, 2ºC night) were resumed for five days, followed by deacclimation with increasing temperature to 20ºC overnight and maintaining for three days. Sampling was done at four different times, each at the 11th hour of light to avoid circadian effects: 1) before chilling treatment, 2) five days after initiation of chilling treatment, 3) eight days into freeze-thaw treatment and 4) three days into de-acclimation.
Project description:Three week old seedlings of rice cultivar Jumli Marshi (spp. Japonica) was exposed to cold (+4C) temperatures for varying time periods. Tissue samples were collected in replicates. Microarray data analysis was then performed on the extracted totalRNA from the samples.
Project description:In this study we used the Affymetrix Barley 1 GeneChip to investigate transcriptome responses of barley cv. Dicktoo to low temperature, including triplicated measurements of cold, freeze/thaw cycles and de-acclimation over 33 days. Experiment Overall Design: Plants were grown at 20ºC for seven days and subject to a symmetrical cycle of acclimation, cold, freeze-thaw, and deacclimation. Chilling began by decreasing the temperature overnight from 20ºC to 4ºC at a rate of 1.3ºC�h-1 and maintaining temperatures of 4 ºC in the day and 2ºC at night for 5 days. Freeze-thaw cycling lasted 12 days with day temperatures of 4ºC and night temperatures gradually decreasing from -2ºC the first night to -4ºC for three nights and -10ºC for four nights, then recovering to -4ºC for three nights and -2ºC for one night. This treatment was designed to allow daily freeze-thaw cycling and protein synthesis. Chilling conditions (4ºC day, 2ºC night) were resumed for five days, followed by deacclimation with increasing temperature to 20ºC overnight and maintaining for three days. Sampling was done at four different times, each at the 11th hour of light to avoid circadian effects: 1) before chilling treatment, 2) five days after initiation of chilling treatment, 3) eight days into freeze-thaw treatment and 4) three days into de-acclimation.
Project description:Purpose: We aimed to provide a basis for the adaptive mechanism and a rich resource for the discovery and identification of novel genes involved in the cold stress response in Solenopsis japonica. Retinal transcriptome profiling (RNA-seq) to microarray and quantitative reverse transcription polymerase chain reaction (qRT–PCR) methods and to evaluate protocols for optimal high-throughput data analysis Methods: Solenopsis japonica was reared at lab condition, and incubated at 2 different temperature for 24h (9, and 25℃) under dark conditions. RNA was extracted using Trizol reagent and Illumina sequencing was performed at Macrogen. Illumina short reads were quality-filtered and Illumina-based de novo transcriptome assembly was performed. Differential Gene Expression Analysis was studied for different tempearture conditions. Results: Totally 89,657 unigenes was obtained which overall 43,375 were annotated with gene descriptions, gene ontology terms, and metabolic pathways. 86 GO functional sub-groups and 25 EggNOG terms resulted. DEGs with FC≥2 and FC≤-2, P-value<0.05 were screened and were compared at two different temperatures. We found 138 DEG down regulated and 271 DEG up regulated when the S. japonica incubated at 9 ℃ and compared with 25℃ treated group. Comparing transcriptome profiles for differential gene expression resulted various DE proteins and genes, including cytochrome P450, NADH dehydrogenase subunit 1, cuticle protein and HSP which have previously been reported to be involved in cold and high temperature resistance. GO analysis revealed that antioxidant activity up-regulated under high temperature stress. Conclusions: we compared the transcriptomes of S. japonica under normal room temperature and low-temperature using RNA-Seq technology based on the high-throughput sequencing. Comparative transcriptome analysis identified many genes and a large number of changes were discovered in metabolic pathway through the GO and KEGG enrichment analysis. Our data will facilitate further molecular investigations and genomic research. Many low-temperature significantly up-regulated genes were first identified in this study. These newly found genes may be important and necessary to S. japonica overwintering and its behavior for adaptation in new environment.
Project description:Arctic Mesorhizobium strain N33 was isolated from nodules of the Oxytropis arctobia in Canada’s eastern Arctic. This symbiotic bacterium can grow from 0 to 30°C, is one of the best known cold-adapted rhizobia, and can fix nitrogen at ~10°C. Here, the key molecular mechanisms of cold adaptation were investigated by determining changes in transcript profiles when cells were treated under eight different temperature conditions, including both sustained and transient cold treatments compared with cells grown at room temperature.
Project description:The cold shock response of B. subtilis was defined after 0.5 hr and 2 hr cold shock using RNA sequencing. We identified novel RNAs (including non-coding RNAs) that play a role during growth at low temperatures. Deletion of the cold induced protein YplP results in a cold sensitive phenotype, and a comparative RNA sequencing analysis suggests that YplP induces pftAB expression after prolonged incubation at low temperatures, thereby optimizing pyruvate transport under cold shock conditions.
Project description:In this study we used the Affymetrix Barley 1 GeneChip to investigate transcriptome responses of barley cv. Morex to low temperature, including triplicated measurements of cold, freeze/thaw cycles and de-acclimation over 33 days. Keywords: stress response
Project description:N6-methyldeoxyadenosine (6mA) is a newly-discovered DNA modification that plays a role in regulating plant adaptation to abiotic stresses. However, the changes and molecular regulatory mechanisms of N6-methyldeoxyadenosine under cold stress in plants remain uncertain. Here, we found the global level of 6mA in both Arabidopsis and rice are raised after cold treatment. Genome-wide profiling of 6mA revealed that 6mA peaks are primarily distributed within gene body regions under both normal and low-temperature conditions. Additionally, genes that were up-methylated were enriched in various biological processes, while down-methylated genes did not exhibit any significant enrichment. Association analysis showed that 6mA was positively correlated with gene expression level and 6mA-containing genes displayed a significantly higher expression level than non-6mA-containing genes. Joint analysis of the 6mA methylome and transcriptome of Arabidopsis and rice revealed that the fluctuations in 6mA levels caused by exposure to cold did not correlate with the changes of transcript levels in response to low temperatures. Moreover, we found that 6mA modified orthologous genes exhibit high expression levels. However, upon cold treatment, only a small amount of differentially 6mA-methylated orthologous genes were shared between Arabidopsis and rice. In sum, this study profiled the changes of 6mA in response to cold temperature and has unlocked the potential of this DNA modification in regulating the expression of stress-related genes.