Project description:Crab is one of the major source for V. parahaemolyticus outbreak among aquatic products in Northeast Asian due to improperly cooking and wound infection by mishandling. However, there is no report on whole genome sequence of V. parahaemolyticus isolated from contaminated crab, thus no information is available for major virulence factors about V. parahaemolyticus obtained from crab. Therefore, the analysis of transcriptome of isolated V. parahaemolyticus from crab products are necessary to investigate potential risk of foodborne illness by contaminated products.
Project description:Chemical modifications to the tails of histone proteins act as gene regulators that play a pivotal role in adaptive responses to environmental stress. Determining the short and long term kinetics of histone marks is essential for understanding their functions in adaptation. We used Caenorhabditis elegans as a model organism to study the histone modification kinetics in response to environmental stress, taking advantage of their ability to live in both terrestrial and aquatic environments. We investigated the multigenerational genome-wide dynamics of five histone marks (H3K4me3, H3K27me3, H4K20me1, H3K36me1, and H3K9me3) by maintaining P0 animals on terrestrial (agar plates), F1 in aquatic cultures, and F2 back on terrestrial environments. We determined the distributions of histone marks in the gene promoter regions and found that H4K20me1, H3K36me1, and H3K9me3 showed up to eleven-fold differences in density, whereas H3K4me3 and H3K27me3 remained highly constant during adaptation from terrestrial to aquatic environments. Furthermore, we predicted that up to five combinations of histone marks can co-occupy single gene promoters and confirmed the colocalization of these histone marks by structured illumination microscopy. The co-occupancy increases with environment changes and different co-occupancy patterns contribute to variances in gene expressions and thereby presents a supporting evidence for the histone code hypothesis.
Project description:Study abstract: Axolotl salamanders (Ambystoma mexicanum) remain aquatic in their natural state, during which biomechanical forces on their diarthrodial limb joints are likely reduced relative to salamanders living on land. However, even as sexually mature adults, these amphibians can be induced to metamorphose into a weight-bearing terrestrial stage by environmental stress or the exogenous administration of thyroxine hormone. In some respects, this aquatic to terrestrial transition of axolotl salamanders through metamorphosis may model developmental and changing biomechanical skeletal forces in mammals during the prenatal to postnatal transition at birth and in the early postnatal period. To assess differences in the appendicular skeleton as a function of metamorphosis, anatomical and gene expression parameters were compared in skeletal tissues between aquatic and terrestrial axolotls that were the same age and genetically full siblings. The length of long bones and area of cuboidal bones in the appendicular skeleton, as well as the cellularity of cartilaginous and interzone tissues of femorotibial joints were generally higher in aquatic axolotls compared to their metamorphosed terrestrial siblings. A comparison of steady state mRNA transcripts encoding aggrecan core protein (ACAN), type II collagen (COL2A1), and growth and differentiation factor 5 (GDF5) in femorotibial cartilaginous and interzone tissues did not reveal any significant differences between aquatic and terrestrial axolotls. RNAseq samples: Total RNA was isolated from whole body tissue samples of Mexican axolotl salamanders (Ambystoma mexicanum) at the following developmental stages: Embryo at the tail bud stage, newly hatched larva, larva at the limb bud stage, juvenile at 8.5 centimeters, and adult using variations of guanidinium-based protocols. RNA quantity, purity, and integrity of both the individual samples and the resulting pool were determined with an Agilent 2100 Bioanalyzer using the Eukaryotic Total RNA nano series II analysis kit. The pooled RNA sample was poly-A selected and used for Illumina random priming directional library prep. Four lanes were sequenced only on one end providing single end reads and 4 lanes were sequenced at both ends giving paired-end reads. The library was sequenced on an Illumina HiSeq 2000 for 75bp reads producing 147,248,512 single end reads and 2 x 153,254,667 paired-end reads.
Project description:<p>Aquatic insects are well-adapted to freshwater environments, but metabolic mechanisms of such adaptations, particularly to primary environmental factors (e.g., hypoxia, water pressure, dark light and abundant microbes), are poorly known. Most firefly species (Coleoptera: Lampyridae) are terrestrial, but the larvae of a few species are aquatic. We generated 24 global metabolomic profiles of larvae and adults of <em>Aquatica leii</em> (freshwater) and <em>Lychnuris praetexta</em> (terrestrial) to identify freshwater adaptation-related metabolites (AARMs). We identified 110 differentially abundant metabolites (DAMs) in <em>A. leii</em> (adults vs aquatic larvae) and 183 DAMs in <em>L. praetexta</em> (adults vs terrestrial larvae). Furthermore, 100 DAMs specific to aquatic <em>A. leii</em> larvae were screened as AARMs via interspecific comparisons (<em>A. leii</em> vs <em>L. praetexta</em>), which were primarily involved in antioxidant activity, immune response, energy production and metabolism, and chitin biosynthesis. They were assigned to six categories/superclasses (e.g., lipids and lipid-like molecules, organic acids and derivatives, and organoheterocyclic compound). Finally, ten metabolic pathways shared between KEGG terms specific to aquatic fireflies and enriched by AARMs were screened as aquatic adaptation-related pathways (AARPs). These AARPs were primarily involved in energy metabolism, xenobiotic biodegradation, protection of oxidative/immune damage, oxidative stress response and sense function (e.g., glycine, serine and threonine metabolism, drug metabolism-cytochrome P450 and taste transduction), and certain aspects of morphology (e.g., steroid hormone biosynthesis). These results provide evidence suggesting that abundance changes in metabolomes contribute to freshwater adaptation of fireflies. The metabolites identified here may be vital targets for future work to determine the mechanism of freshwater adaptation in insects.</p>
Project description:During the evolution of life on Earth, the conquest of land by plants played a pivotal role producing a boost in land biomass, a substantial drop in atmospheric CO2, an increase in oxygen and the emergence of new terrestrial habitats facilitating land colonization by animals. Therefore, the characterization of the molecular mechanisms that allowed plant terrestralization is a cornerstone in evolutionary studies. Viridiplantae or the green lineage is divided into two clades Chlorophyta or green microalgae and Streptophyta that in turn splits into Embryophyta or land plants and Charophyta. The latest are mainly considered aquatic algae although some facultative terrestrial species has been identified. Charophyta are generally accepted as the extant algal species most closely related to current land plants and, therefore, they are used in evolutionary studies on plant terrestralization. High light irradiance was one of the major stressors that ancestral charophytic algae needed to overcome during the transition from aquatic to terrestrial environments. In this study, we have chosen the facultative terrestrial early charophytic alga Klebsormidium nitens to perform an integrative transcriptomic and metabolomic analysis under high light in order to unveil key mechanisms involved in the early steps of plants terrestralization. We found a fast chloroplast retrograde signaling possibly mediated by reactive oxygen species and the inositol polyphosphate 1-phosphatase (SAL1) and 3′-phosphoadenosine-5′-phosphate (PAP) pathways inducing gene expression and accumulation of specific metabolites. Systems used by both Chlorophyta and Embryophyta were activated such as the xanthophyll cycle with an accumulation of zeaxanthin and protein folding and repair mechanisms constituted by NADPH-dependent thioredoxin reductases, thioredoxin-disulfide reductases and peroxiredoxins. Similarly, cyclic electron flow, specifically the pathway dependent on Proton Gradient Regulation 5, was strongly activated under high light. We detected a simultaneous co-activation of the non-photochemical quenching mechanisms based on LHC-like Stress Related protein and the photosystem II subunit S that are specific to Chlorophyta and Embryophyta respectively. Exclusive Embryophyta systems for the synthesis, sensing and response to the phytohormone auxin were also activated under high light in Klebsormidium leading to an increase in auxin content with the concomitant accumulation of amino acids such as tryptophan, histidine and phenylalanine.
Project description:Marine is one of the most important resources of microorganisms, including bacteria, actinomycetes, and fungi. As marine and terrestrial environments differ a lot in many aspects it is not surprising that the species and characteristics of microorganisms living there are very different. Interestingly, many marine microorganisms can find their congeners of the same species from terrestrial resources. The aim of this work is to evaluate the intraspecies differences between marine and terrestrial actinomycetes on metabolic level and to uncover the mechanism responsible for the differences. To address this, we carried out comparative metabolomics study on Nesterenkonia flava strains isolated from marine and terrestrial environments. The results showed that marine strains were clearly distinguished from their terrestrial congeners on the principal components analysis (PCA) scores plot of intracellular metabolites. The markers responsible for the discrimination of marine and terrestrial strains were figured out using loading plot from partial least squares discrimination analysis (PLS-DA). Pathway analysis based on PLS-DA, univariate analysis, and correlation analysis of metabolites showed that the major differential metabolites between the terrestrial N. flava and the marine ones were involved in osmotic regulation, redox balancing, and energy metabolism. Together, these insights provide clues as to how the previous living environment of microbes affect their current metabolic performances under laboratory cultivation conditions.
Project description:Background: The Scylla paramamosain is a very important aquaculture crustacean species in the southeast coastal areas of China including Shantou. For the past few years, mud crab cultured in Niutianyang of Shantou suffered from serious diseases, especially the bacterial diseases (such as Vibrio parahaemolyticus). In eukaryotes, small RNAs can regulate gene expression in post-transcription to act on host-pathogen interaction system. Aims: V.parahaemolyticus isolated from Shantou Niutianyang crab culture area was injected to S.paramamosains to carry out an essential analysis on global miRNA expression in diverse tissues between two groups by the Illumina Solex deep sequencing technology. Methodology:To examine the relationship between mud crab miRNA expression and the bacterial pathogen, we collected mixed two pools of equal amounts of RNA from 7 different mud crab tissues (mesenteron, heart, liver, gill, brain, muscle and blood) and sequencing by Illumine/Solexa deep sequencing technology under normal conditions and during infection with V.parahaemolyticus. The high throughput sequencing resulted in 19,144,358 and 18,559,070 raw reads corresponding to 17,496,577 and 16,888,096 high-quality mappable reads for the normal and infected mixed pools, respectively. Stem-loop RT-qPCRs were used to confirm the microRNAs expression in different tissues of two pools. The results show that miRNAs might play a key role in regulating gene expression during mud crab S.paramamosain infection with V.parahaemolyticus. Conclusions: We identified a large number of miRNAs during the mud crab Scylla paramamosain infection with V.parahaemolyticus, some of which are differentially expressed between the treatments and the controls. The study provides an opportunity for further understanding of small RNA function in the regulation of molecular response and gives us clues for further studies of the mechanisms of V.parahaemolyticus infection in mud crab.