Project description:Transcriptional profiling of populations in the clam Ruditapes decussatus determined differentiation in gene-expression along parallel temperature gradients and between races of the Atlantic Ocean and West Mediterranean sea.
Project description:Sulfate-reducing bacteria (SRB) are ubiquitously distributed across various biospheres and play key roles in global sulfur and carbon cycles. However, few deep-sea SRB have been cultivated and studied in situ, limiting our understanding of the true metabolism of SRB in the deep biosphere. Here, we firstly clarified the high abundance of SRB in deep-sea sediments via the operational taxonomic units (OTU) sequencing analysis. We have successfully isolated a sulfate-reducing bacterium (strain zrk46) from a cold seep sediment, by using an enriched medium supplemented with sulfate. Our genomic, physiological and phylogenetic analyses indicate that strain zrk46 is a novel species, which we propose be named: Pseudodesulfovibrio serpens. Based on the combined results from growth assays and proteomic analyses, we found that supplementation with sulfate (SO42-), thiosulfate (S2O32-), or sulfite (SO32-) promoted the growth of strain zrk46 by facilitating energy production through the dissimilatory sulfate reduction with the auxiliary functions of heterodisulfide reductases, ferredoxins, and nitrate reduction associated proteins, which were coupled to the oxidation of environmental organic matter in both laboratory and deep-sea in situ conditions. Moreover, metatranscriptomic results have also confirmed the dissimilatory sulfate reduction of deep-sea SRB in in situ environment, which might be coupled to the methane oxidation of anaerobic methanotrophic archaea (ANME-2). Overall, these findings expand our understanding of deep-sea SRB, while highlighting their importance for deep-sea sulfur and carbon cycles.
Project description:Physiological and gene expression studies of deep-sea bacteria under pressure conditions similar to those experienced in their natural habitat are critical to understand growth kinetics and metabolic adaptations to in situ conditions. The Epslilonproteobacterium, Nautilia sp. strain PV1, was isolated from hydrothermal fluids released from an active deep-sea hydrothermal vent at 9°N on the East Pacific Rise. Using a high pressure/high temperature continuous culture system we established that strain PV-1 has the shortest generation time of all known piezophilic microorganisms and we investigated its protein expression pattern in response to different hydrostatic pressures. Proteomic analyses of strain PV-1 grown at 200 Bars and 5 Bars showed that pressure adaptation is not restricted only to stress response or homeoviscous adaptation, but that it is more diversified and protein specific, with a fine and variegated regulation of enzymes involved even in the same metabolic pathway. As previously reported, proteins synthesis, motility, transport and energy metabolism are all affected by pressure, although to different extents. In strain PV-1, low pressure condition seems to activate the synthesis of phage-related proteins and an overexpression of enzymes involved in central carbon metabolism.
Project description:Analysis of gene expression changes of Mesorhizobium alhagi CCNWXJ12-2 under high salt stress. Mesorhizobium alhagi CCNWXJ12-2 is isolated from Alhagi sparsifolia in northwest of China.
Project description:We genotyped 45 new samples from 4 populations of Northwest India and combined it with previously published data to characterize the population structure of modern Northwest Indian populations in the context of their geographic neighbors across South Asia and West Eurasia.
Project description:The goal of this study was to determine how decreased mitochondrial citrate export influences gene expression in Drosophila larvae. RNA was isolated from Drosopohila sea mutants, which exhibiti decreased mitochondrial citrate transport activity, and a genetically-matched control strain during mid-L3 development.
