White Mars
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REPOSITORIES: ENA
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Project description:Effect of season and winter lattitude on gene expression in Antarctic krill.
2012-11-01 | E-MEXP-3453 | biostudies-arrayexpress
Project description:BACKGROUND: Polar environments are characterized by extreme seasonal changes in day length, light intensity and spectrum, the extent of sea ice during the winter, and food availability. A key species of the Southern Ocean ecosystem, the Antarctic krill (Euphausia superba) has evolved rhythmic physiological and behavioral mechanisms to adapt to daily and seasonal changes. The molecular organization of the clockwork underlying these biological rhythms is, nevertheless, still only partially understood. METHODOLOGY/PRINCIPAL FINDINGS:The genome sequence of the Antarctic krill is not yet available. A normalized cDNA library was produced and pyrosequenced in the attempt to identify large numbers of transcripts. All available E. superba sequences were then assembled to create the most complete existing oligonucleotide microarray platform with a total of 32,217 probes. Gene expression signatures of specimens collected in the Ross Sea at five different time points over a 24-hour cycle were defined, and 1,308 genes differentially expressed were identified. Of the corresponding transcripts, 609 showed a significant sinusoidal expression pattern; about 40% of these exibithed a 24-hour periodicity while the other 60% was characterized by a shorter (about 12-hour) rhythm. We assigned the differentially expressed genes to functional categories and noticed that those concerning translation, proteolysis, energy and metabolic process, redox regulation, visual transduction and stress response, which are most likely related to daily environmental changes, were significantly enriched. Two transcripts of peroxiredoxin, thought to represent the ancestral timekeeping system that evolved about 2.5 billion years ago, were also identified as were two isoforms of the EsRh1 opsin and two novel arrestin1 sequences involved in the visual transduction cascade. CONCLUSIONS: Our work represents the first characterization of the krill diurnal transcriptome under natural conditions and provides a first insight into the genetic regulation of physiological changes, which occur around the clock during an Antarctic summer day
2013-07-23 | GSE42292 | GEO
Project description:The sea-ice dwelling diatom Fragilariopsis Cylindrus was cultured for 4 months under dark or light exposed conditions to mimic the effects of Antarctic winter growth conditions. Cells were harvested periodically and LFQ proteomics used to investigate the molecular mechanisms of dark survival.
2019-04-23 | PXD007098 | Pride
Project description:The experiment aimed to investigate seasonal and regional differences in gene expression in Antarctic krill in three different latitudinal regions of the Southern Ocean with variable photoperiodic conditions: South Georgia (54°S), South Orkneys/Bransfield Strait (60°S-63°S) and Lazarev Sea (62°S -66°S). An RNAseq approach was used to test for (1) seasonal differences in gene expression between summer and winter krill from each region, and (2) regional differences in gene expression between the three different regional krill samples from each season. The RNAseq data was analysed with the goal to identify potential seasonal target genes with regulatory functions in the seasonal life cycle of Antarctic krill, focussing on genes related to regulation, reproduction, development and visual perception.
2020-08-12 | E-MTAB-7467 | biostudies-arrayexpress
Project description:BACKGROUND: Polar environments are characterized by extreme seasonal changes in day length, light intensity and spectrum, the extent of sea ice during the winter, and food availability. A key species of the Southern Ocean ecosystem, the Antarctic krill (Euphausia superba) has evolved rhythmic physiological and behavioral mechanisms to adapt to daily and seasonal changes. The molecular organization of the clockwork underlying these biological rhythms is, nevertheless, still only partially understood. METHODOLOGY/PRINCIPAL FINDINGS:The genome sequence of the Antarctic krill is not yet available. A normalized cDNA library was produced and pyrosequenced in the attempt to identify large numbers of transcripts. All available E. superba sequences were then assembled to create the most complete existing oligonucleotide microarray platform with a total of 32,217 probes. Gene expression signatures of specimens collected in the Ross Sea at five different time points over a 24-hour cycle were defined, and 1,308 genes differentially expressed were identified. Of the corresponding transcripts, 609 showed a significant sinusoidal expression pattern; about 40% of these exibithed a 24-hour periodicity while the other 60% was characterized by a shorter (about 12-hour) rhythm. We assigned the differentially expressed genes to functional categories and noticed that those concerning translation, proteolysis, energy and metabolic process, redox regulation, visual transduction and stress response, which are most likely related to daily environmental changes, were significantly enriched. Two transcripts of peroxiredoxin, thought to represent the ancestral timekeeping system that evolved about 2.5 billion years ago, were also identified as were two isoforms of the EsRh1 opsin and two novel arrestin1 sequences involved in the visual transduction cascade. CONCLUSIONS: Our work represents the first characterization of the krill diurnal transcriptome under natural conditions and provides a first insight into the genetic regulation of physiological changes, which occur around the clock during an Antarctic summer day Gene expression profiling was carried out in krill fished at different times throughout the 24 hours cycle (local times: 01:00, 06:00, 10:00, 15:00, and 18:00) with the M-bM-^@M-^XM-bM-^@M-^XKrill 1.1M-bM-^@M-^YM-bM-^@M-^Y custom platform (Agilent). We analyzed four different biological replicates for each time point for a total of 20 microarray experiments.
2013-07-23 | E-GEOD-42292 | biostudies-arrayexpress
Project description:Because of severe abiotic limitations, Antarctic soils represent simplified ecosystems, where microorganisms are the principle drivers of nutrient cycling. This relative simplicity makes these ecosystems particularly vulnerable to perturbations, like global warming, and the Antarctic Peninsula is among the most rapidly warming regions on the planet. However, the consequences of the ongoing warming of Antarctica on microorganisms and the processes they mediate are unknown. Here, using 16S rRNA gene pyrosequencing and qPCR, we report a number of highly consistent changes in microbial community structure and abundance across very disparate sub-Antarctic and Antarctic environments following three years of experimental field warming (+ 0.5-2°C). Specifically, we found significant increases in the abundance of fungi and bacteria and in the Alphaproteobacteria-to-Acidobacteria ratio. These alterations were linked to a significant increase in soil respiration. Furthermore, the shifts toward generalist or opportunistic bacterial communities following warming weakened the linkage between bacterial diversity and functional diversity. Warming also increased the abundance of some organisms related to the N-cycle, detected as an increase in the relative abundance of nitrogenase genes via GeoChip microarray analyses. Our results demonstrate that soil microorganisms across a range of sub-Antarctic and Antarctic environments can respond consistently and rapidly to increasing temperatures, thereby potentially disrupting soil functioning.
2010-12-30 | GSE22825 | GEO
Project description:Tea (Camellia sinensis (L.) O. Kuntze) is an important non-alcoholic commercial beverage crop. Tea tree is a perennial plant, and winter dormancy is its part of biological adaptation to environmental changes. We recently discovered a novel tea tree cultivar that can generate tender shoots in winter, but the regulatory mechanism of this ever-growing tender shoot development in winter is not clear. In this study, we conducted a proteomic analysis for identification of key genes and proteins differentially expressed between the winter and spring tender shoots, to explore the putative regulatory mechanisms and physiological basis of its ever-growing character during winter.
2022-02-23 | PXD008958 | Pride
Project description:Metagenome collected from Antarctic marine bacterioplankton in winter
| PRJNA30011 | ENA
Project description:Trans-10, Cis-12 conjugated linoleic acid (t10c12 CLA) causes fat loss in mouse white adipose tissue (WAT). The early transcriptome changes in WAT were analyzed using high-density microarrays to better characterize the signaling pathways responding to t10c12 CLA. Their gene expression responses between 4 to 24 hr after treatment showed a common set of early gene expression changes indicative of an integrated stress response (ISR). Keywords: control/treatment time course
2008-01-11 | GSE8679 | GEO
Project description:Recently, intensive global climate change has become a major factor impacting plant survival during the winter. Freezing cold temperatures during the winter and abnormal temperature fluctuations during the winter and early spring are the most harmful ambient factors threatening tea plant winter survival and currently cause marked economic losses in tea production. In this study, by simulating natural climate change, we established cold acclimation (CA) and rapid cold stress (after CA) conditions to comprehensively investigate the transcriptome changes involved in CA and rapid cold stress. Electrolyte leakage (EL) rate and expression profile clustering analyses confirmed that the experimental design was valid. Comparative transcription analysis identified many differentially expressed genes (DEGs) involved in both processes. Time course and pathway enrichment analyses further revealed the physiological changes that occur during the initial period of CA and the cell wall changes that occur throughout the entire CA process; these changes play crucial roles in increasing freezing tolerance during this process. Compared with CA, different cold response mechanisms were rapidly activated under cold stress; however, the subsequent accumulation of reactive oxygen species, which affect multiple aspects, caused by freezing cold could be the harshest factor impairing tea leaves. Moreover, we investigated 60 DEGs shared by both processes and highlighted the importance of KCSs, HXXXD-type acyl-transferase family proteins, NAC080, SWEETs and ENOs in the responses to various cold conditions. These results greatly improve our knowledge of cold response mechanisms in tea plants and provide meaningful information for functional studies investigating cold tolerance-related genes.
2017-09-29 | GSE104390 | GEO