Integrated Metabonomic-Proteomic Analysis of an Insect-Bacterial Symbiotic System

The health of animals, including humans, is dependent on their resident microbiota, but the complexity of the microbial communities makes these associations difficult to study in most animals. Exceptionally, the microbiology of the pea aphid Acyrthosiphon pisum is dominated by a single bacterium Buchnera aphidicola (B. aphidicola). A 1H NMR-based metabonomic strategy was applied to investigate metabolic profiles of aphids fed on a low essential amino acid diet and treated by antibiotic to eliminate B. aphidicola. In addition, differential gel electrophoresis (DIGE) with mass spectrometry was utilized to determine the alterations of proteins induced by these treatments. We found that these perturbations resulted in significant changes to the abundance of 15 metabolites and 238 proteins. Ten (67%) of the metabolites with altered abundance were amino acids, with nonessential amino acids increased and essential amino acids decreased by both perturbations. Over-represented proteins in the perturbed treatments included catabolic enzymes with roles in amino acid degradation and glycolysis, various cuticular proteins, and a C-type lectin and regucalcin with candidate defensive roles. This analysis demonstrates the central role of essential amino acid production in the relationship and identifies candidate proteins and processes underpinning the function and persistence of the association

Global metabolic responses of the lenok (Brachymystax lenok) to thermal stress

High temperature is a powerful stressor for fish living in natural and artificial environments, especially for cold water species. Understanding the impact of thermal stress on physiological processes of fish is crucial for better cultivation and fisheries management. However, the metabolic mechanism of cold water fish to thermal stress is still not completely clear. In this study, a NMR-based metabonomic strategy in combination with high throughput RNA-Seq was employed to investigate global metabolic changes of plasma and liver in a typical cold water fish species lenok (Brachymystax lenok) subjected to a sub-lethal high temperature. Our results showed that thermal stress caused multiple dynamic metabolic alterations of the lenok with prolonged stress, including repression of energy metabolism, shifts in lipid metabolism, alterations in amino acid metabolism, changes in choline and nucleotide metabolisms. Specifically, thermal stress induced an activation of glutamate metabolism, indicating that glutamate could be an important biomarker associated with thermal stress. Evidence from Hsp 70 gene expression, blood biochemistry and histology confirmed that high temperature exposure had negative effects on health of the lenok. These findings imply that thermal stress has a severe adverse effect on fish health and demonstrate that the integrated analyses combining NMR-based metabonomics and transcriptome strategy is a powerful approach to enhance our understanding of metabolic mechanisms of fish to thermal stress.</p

A Novel Candidate Gene Associated With Body Weight in the Pacific White Shrimp Litopenaeus vannamei

Improvements of growth traits are always the focus in selective breeding programs for the Pacific white shrimp Litopenaeus vannamei (L. vannamei). Identification of growth-related genes or markers can contribute to the application of modern breeding technologies, and thus accelerate the genetic improvement of growth traits. The aim of this study was to identify the genes and molecular markers associated with the growth traits of L. vannamei. A population of 200 individuals was genotyped using 2b-RAD techniques for genome-wide linkage disequilibrium (LD) analysis and genome-wide association study (GWAS). The results showed that the LD decayed fast in the studied population, which suggest that it is feasible to fine map the growth-related genes with GWAS in L. vannamei. One gene designated as LvSRC, encoding the class C scavenger receptor (SRC), was identified as a growth-related candidate gene by GWAS. Further targeted sequencing of the candidate gene in another population of 322 shrimps revealed that several non-synonymous mutations within LvSRC were significantly associated with the body weight (P &lt; 0.01), and the most significant marker (SRC_24) located in the candidate gene could explain 13% of phenotypic variance. The current results provide not only molecular markers for genetic improvement in L. vannamei, but also new insights for understanding the growth regulation mechanism in penaeid shrimp

Ultrathin Few-Layer GeP Nanosheets via Lithiation-Assisted Chemical Exfoliation and Their Application in Sodium Storage

2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Ultrathin few-layer materials have attracted intensive research attention because of their distinctive and unique properties. Few-layer GeP (FL-GP) is potentially interesting for application in electronics and optoelectronics because of its appropriate band gap and good stability under ambient conditions. Nevertheless, it is a challenge to achieve ultrathin few-layer or single layer GeP from exfoliation of bulk crystals. Here, a lithiation-assisted chemical exfoliation technique is employed to achieve FL-GP, in which the interlayer spacing can be efficiently enlarged after a preliminary lithium ion intercalation, allowing the bulk crystal to be readily exfoliated in a following ultrasonication. As a result, ultrathin FL-GP is obtained. In a demonstration, the FL-GP/reduced graphene oxide (rGO) demonstrates remarkable sodium storage performance. The FL-GP with a two-dimensional structure shortens the ion transport pathways and alleviates the volume variation during sodiation. Meanwhile, the rGO in the composite improves the conductivity of the whole electrode. The as-prepared FL-GP/rGO electrode exhibits a high capacity of 504.2 mAh g−1 at 100 mA g−1, remarkable rate performance, and superior cycling stability in the half cells. FL-GP/rGO//Na3V2(PO4)3 full cells are also assembled and demonstrated satisfactory electrochemical performance, indicating potential application of the as-prepared anode materials

Metabonomics uncovers a reversible proatherogenic lipid profile during infliximab therapy of inflammatory bowel disease

Background: One-third of inflammatory bowel disease (IBD) patients show no response to infliximab (IFX) induction therapy, and approximately half of patients responding become unresponsive over time. Thus, identification of potential treatment response biomarkers are of great clinical significance. This study employs spectroscopy-based metabolic profiling of serum from patients with IBD treated with IFX and healthy subjects (1) to substantiate the use of spectroscopy as a semi-invasive diagnostic tool, (2) to identify potential biomarkers of treatment response and (3) to characterise the metabolic changes during management of patients with tumour necrosis factor-α inhibitors.Methods: Successive serum samples collected during IFX induction treatment (weeks 0, 2, 6 and 14) from 87 IBD patients and 37 controls were analysed by 1H nuclear magnetic resonance (NMR) spectroscopy. Data were analysed with principal components analysis and orthogonal projection to latent structures discriminant analysis using SIMCA-P+ v12 and MATLAB.Results: Metabolic profiles were significantly different between active ulcerative colitis and controls, active Crohn's disease and controls, and quiescent Crohn's disease and controls. Metabolites holding differential power belonged primarily to lipids and phospholipids with proatherogenic characteristics and metabolites in the pyruvate metabolism, suggestive of an intense inflammation-driven energy demand. IBD patients not responding to IFX were identified as a potentially distinct group based on their metabolic profile, although no applicable response biomarkers could be singled out in the current setting.Conclusion: 1H NMR spectroscopy of serum samples is a powerful semi-invasive diagnostic tool in flaring IBD. With its use, we provide unique insights into the metabolic changes taking place during induction treatment with IFX. Of distinct clinical relevance is the identification of a reversible proatherogenic lipid profile in IBD patients with active disease, which partially explains the increased risk of cardiovascular disease associated with IBD

Three-Dimensional Porous Cobalt Phosphide Nanocubes Encapsulated in a Graphene Aerogel as an Advanced Anode with High Coulombic Efficiency for High-Energy Lithium-Ion Batteries

An ingeniously designed porous structure can synergistically optimize the desired properties and maximize the advantages of a material as an electrode for a high-performance energy storage system. The active material with a porous nanostructure could reduce the ion diffusion path and buffer the strain caused by the volume changes during cycling. Furthermore, combining the active material with a three-dimensional (3D) graphene aerogel (GA) matrix is an ideal way to maintain the structural integrity, improve the conductivity, and overcome the aggregation problem of the nanomaterials. Herein, we adopted a facile template-based strategy to derive a composite of 3D hierarchically porous cobalt phosphide nanocubes with a graphene aerogel (CoP@GA). The as-prepared CoP@GA features porous cobalt phosphide nanocubes that are firmly encapsulated and uniformly distributed in the well-defined graphene aerogel skeleton. Benefiting from the hierarchical porosity, structural integrity, and conductive network, the CoP@GA electrode manifests an ultrahigh initial Coulombic efficiency (88.6%), outstanding lithium storage performance in terms of excellent cycling performance (805.3 mAh·g-1 after 200 cycles at 200 mA·g-1), superior high-energy performance (351.8 mAh·g-1 after 4000 cycles at 10 A·g-1), and exceptional rate capability. Moreover, this synthesis protocol could be an instructive precedent for fabricating transition-metal-phosphide-based 3D porous composites with excellent electrochemical performances

Three-Dimensional Porous Cobalt Phosphide Nanocubes Encapsulated in a Graphene Aerogel as an Advanced Anode with High Coulombic Efficiency for High-Energy Lithium-Ion Batteries

An ingeniously designed porous structure can synergistically optimize the desired properties and maximize the advantages of a material as an electrode for a high-performance energy storage system. The active material with a porous nanostructure could reduce the ion diffusion path and buffer the strain caused by the volume changes during cycling. Furthermore, combining the active material with a three-dimensional (3D) graphene aerogel (GA) matrix is an ideal way to maintain the structural integrity, improve the conductivity, and overcome the aggregation problem of the nanomaterials. Herein, we adopted a facile template-based strategy to derive a composite of 3D hierarchically porous cobalt phosphide nanocubes with a graphene aerogel (CoP@GA). The as-prepared CoP@GA features porous cobalt phosphide nanocubes that are firmly encapsulated and uniformly distributed in the well-defined graphene aerogel skeleton. Benefiting from the hierarchical porosity, structural integrity, and conductive network, the CoP@GA electrode manifests an ultrahigh initial Coulombic efficiency (88.6%), outstanding lithium storage performance in terms of excellent cycling performance (805.3 mAh·g-1 after 200 cycles at 200 mA·g-1), superior high-energy performance (351.8 mAh·g-1 after 4000 cycles at 10 A·g-1), and exceptional rate capability. Moreover, this synthesis protocol could be an instructive precedent for fabricating transition-metal-phosphide-based 3D porous composites with excellent electrochemical performances

Yolk-Shell Structured FeP@C Nanoboxes as Advanced Anode Materials for Rechargeable Lithium-/Potassium-Ion Batteries

Maintaining structural stability and alleviating the intrinsic poor conductivity of conversion-type reaction anode materials are of great importance for practical application. Introducing void space and a highly conductive host to accommodate the volume changes and enhance the conductivity would be a smart design to achieve robust construction; effective electron and ion transportation, thus, lead to prolonged cycling life and excellent rate performance. Herein, uniform yolk-shell FeP@C nanoboxes (FeP@CNBs) with the inner FeP nanoparticles completely protected by a thin and self-supported carbon shell are synthesized through a phosphidation process with yolk-shell Fe 2 O 3 @CNBs as a precursor. The volumetric variation of the inner FeP nanoparticles during cycling is alleviated, and the FeP nanoparticles can expand without deforming the carbon shell, thanks to the internal void space of the unique yolk-shell structure, thus preserving the electrode microstructure. Furthermore, the presence of the highly conductive carbon shell enhances the conductivity of the whole electrode. Benefiting from the unique design of the yolk-shell structure, the FeP@CNBs manifests remarkable lithium/potassium storage performance