Project description:Metabolomics Analysis of a novel freshwater cyanobacterium, Synechococcus elongatus PCC 11802 isolated by us from Powai Lake, Mumbai, India. PCC 11802 cells were grown under ambient and 1% CO2 conditions and metabolomics data was collected in three biological replicates and two technical replicates (n=6). The study aims to find metabolomics changes in this cyanobacterium at elevated CO2 levels.
Project description:The function of cvpA, a bacterial gene predicted to encode an inner membrane protein, is largely unknown. Early studies in E. coli linked cvpA to Colicin V secretion and recent work revealed that it is required for robust intestinal colonization by diverse enteric pathogens. In enterohemorrhagic E. coli (EHEC), cvpA is required for resistance to the bile salt deoxycholate (DOC). Here, we carried out genome-scale transposon-insertion mutagenesis and spontaneous suppressor analysis to uncover cvpA’s genetic interactions and identify common pathways that rescue the sensitivity of a ∆cvpA EHEC mutant to DOC. These screens demonstrated that mutations predicted to activate the σE-mediated extracytoplasmic stress response bypass the ∆cvpA mutant’s susceptibility to DOC. Consistent with this idea, we found that deletions in rseA and msbB and direct overexpression of rpoE restored DOC resistance to the ∆cvpA mutant. Analysis of the distribution of CvpA homologs revealed that this inner membrane protein is conserved across diverse bacterial phyla, in both enteric and non-enteric bacteria that are not exposed to bile. Together, our findings suggest that CvpA plays a role in cell envelope homeostasis in response to DOC and similar stress stimuli in diverse bacteria.
Project description:Gymnocypris przewalskii przewalskii is distributed in Qinghai Lake, the largest inland saltwater lake in China. It is the only Cyprinidae fish in the Qinghai Lake water system and has extremely strong adaptability to the ecological environment with high salinity. G. p. przewalskii originates from the freshwater species Gymnocypris eckloni eckloni in the Yellow River and has a freshwater subspecies, Gymnocypris przewalskii ganzihonensis, distributed in the Ganzi River. Therefore, G. p. przewalskii is considered an ideal material for studying the high salt adaptation of plateau fish. Previous studies have characterized the evolutionary basis of highland adaptation in G. p. przewalskii; however, its adaptability to highly saline aquatic environments remains elusive. In the current study, we performed physiological, histological, genomic and transcriptomic analyses to investigate the phenotypical adaptation of G. p. przewalskii to a high saline environment and the underlying genomic and regulatory bases.
Project description:Illumina high-throughput sequencing was used to analyse the intestinal bacteria of these two species during different wintering periods at Shengjin Lake. We tested whether contact time enhances the trans-species spread of gut bacteria. Our results indicate that although intestinal microflora of hooded crane and the bean goose were different, direct or indirect contact in the mixed-species flock caused the spread of gut bacteria trans-species, and a very high proportion of common pathogens among these two hosts.
Project description:To study long-term elevated CO2 and enriched N deposition interactive effects on microbial community and soil ecoprocess, here we investigated soil microbial community in a grassland ecosystem subjected to ambient CO2 (aCO2, 368 ppm), elevated CO2 (eCO2, 560 ppm), ambient nitrogen deposition (aN) or elevated nitrogen deposition (eN) treatments for a decade. There exist antagonistic CO2×N interactions on microbial functional genes associated with C, N, P S cycling processes. More strong antagonistic CO2×N interactions are observed on C degradation genes than other genes. Remarkably antagonistic CO2×N interactions on soil microbial communities could enhance soil C accumulation.
Project description:Transcripts of the gill epithelium from three different stocks of Atlantic salmon (Salmo salar) migrating from freshwater river to lake (Saimaa stock, SS), brackish water (Neva stock, NS) or seawater (Teno stock, TS) were compared at three successive developmental stages (parr, smolt and postsmolt) using the 16K GRASP cDNA microarray platform.
Project description:To study whether and how soil nitrogen conditions affect the ecological effects of long-term elevated CO2 on microbial community and soil ecoprocess, here we investigated soil microbial community in a grassland ecosystem subjected to ambient CO2 (aCO2, 368 ppm), elevated CO2 (eCO2, 560 ppm), ambient nitrogen deposition (aN) or elevated nitrogen deposition (eN) treatments for a decade. Under the aN condition, a majority of microbial function genes, as measured by GeoChip 4.0, were increased in relative abundance or remained unchanged by eCO2. Under the eN condition, most of functional genes associated with carbon, nitrogen and sulfur cycling, energy processes, organic remediation and stress responses were decreased or remained unchanged by eCO2, while genes associated with antibiotics and metal resistance were increased. The eCO2 effects on fungi and archaea were largely similar under both nitrogen conditions, but differed substantially for bacteria. Coupling of microbial carbon or nitrogen cycling genes, represented by positive percentage and density of gene interaction in association networks, was higher under the aN condition. In accordance, changes of soil CO2 flux, net N mineralization, ammonification and nitrification was higher under the aN condition. Collectively, these results demonstrated that eCO2 effects are contingent on nitrogen conditions, underscoring the difficulty toward predictive modeling of soil ecosystem and ecoprocesses under future climate scenarios and necessitating more detailed studies.
Project description:To study whether and how soil nitrogen conditions affect the ecological effects of long-term elevated CO2 on microbial community and soil ecoprocess, here we investigated soil microbial community in a grassland ecosystem subjected to ambient CO2 (aCO2, 368 ppm), elevated CO2 (eCO2, 560 ppm), ambient nitrogen deposition (aN) or elevated nitrogen deposition (eN) treatments for a decade. Under the aN condition, a majority of microbial function genes, as measured by GeoChip 4.0, were increased in relative abundance or remained unchanged by eCO2. Under the eN condition, most of functional genes associated with carbon, nitrogen and sulfur cycling, energy processes, organic remediation and stress responses were decreased or remained unchanged by eCO2, while genes associated with antibiotics and metal resistance were increased. The eCO2 effects on fungi and archaea were largely similar under both nitrogen conditions, but differed substantially for bacteria. Coupling of microbial carbon or nitrogen cycling genes, represented by positive percentage and density of gene interaction in association networks, was higher under the aN condition. In accordance, changes of soil CO2 flux, net N mineralization, ammonification and nitrification was higher under the aN condition. Collectively, these results demonstrated that eCO2 effects are contingent on nitrogen conditions, underscoring the difficulty toward predictive modeling of soil ecosystem and ecoprocesses under future climate scenarios and necessitating more detailed studies. Fourty eight samples were collected for four different carbon and nitrogen treatment levels (aCaN,eCaN,aCeN and eCeN) ; Twelve replicates in every elevation
Project description:Cryptomonas sp. was grown under phototrophic conditions, glucose supplemented phototrophic conditions and 3 different dissolved organic carbon (DOC) concentrations: 1.5, 30 and 90 mg C l−1. The objective was to study the adaptations that make Cryptomonas sp. thrive under high DOC conditions.
Project description:We examined adaptive morphological divergence and epigenetic variation in genetically impoverished asexual populations of a freshwater snail, Potamopyrgus antipodarum from distinct environments. These populations exhibit environment-specific adaptive divergence in shell shape and significant genome wide DNA methylation differences among differentially adapted lake and fast water flow river populations. The epigenetic variation correlated with adaptive phenotypic variation in rapidly adapting asexual animal populations. This provides one of the first examples of environmentally-driven differences in epigenetics that associates with adaptive phenotypic divergence.