Oxygen tension modulates extracellular vesicles and its miRNA contents in bovine embryo culture medium

The biotechnology for in vitro embryo production is becoming increasingly popular, being applied to humans and domestic animals. Embryo development can be achieved with either 20% or 5% oxygen tension. The extracellular vesicles (EVs) are secreted by different cell types and carry bioactive materials. Our objective was to determine the secretion pattern and micro RNA (miRNA) contents of EVs released in the bovine embryo culture environment—embryo and cumulus cell monolayer—on Days 3 and 7 of in vitro culture under two different oxygen tensions: High (20%) and low (5%). The EVs were isolated from the medium and analyzed to determine size, concentration, and miRNA levels. EVs concentration in low oxygen tension increased on Day 3 and decreased on Day 7. Additionally, altered EV miRNAs derived from the embryo‐cumulus culture medium were predicted to regulate survival and proliferation‐related pathways on Days 3 and 7. Moreover, miR‐210 levels decreased in EVs isolated from the culture medium under high oxygen tension suggesting that this miRNA can be used as a marker for normoxia since it is associated with low oxygen tension. In summary, this study provides knowledge of the oxygen tension effects on EVs release and content, and potentially, on cell‐to‐cell communication during in vitro bovine embryo production.     

Temporal changes in fish diversity in lotic and lentic environments along a reservoir cascade

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Multitaxon activity profiling reveals differential microbial response to reduced seawater pH and oil pollution

There is growing concern that predicted changes to global ocean chemistry will interact with anthropogenic pollution to significantly alter marine microbial composition and function. However, knowledge of the compounding effects of climate change stressors and anthropogenic pollution is limited. Here, we used 16S and 18S rRNA (cDNA)‐based activity profiling to investigate the differential responses of selected microbial taxa to ocean acidification and oil hydrocarbon contamination under controlled laboratory conditions. Our results revealed that a lower relative abundance of sulphate‐reducing bacteria (Desulfosarcina/Desulfococcus clade) due to an adverse effect of seawater acidification and oil hydrocarbon contamination (reduced pH–oil treatment) may be coupled to changes in sediment archaeal communities. In particular, we observed a pronounced compositional shift and marked reduction in the prevalence of otherwise abundant operational taxonomic units (OTUs) belonging to the archaeal Marine Benthic Group B and Marine Hydrothermal Vent Group (MHVG) in the reduced pH–oil treatment. Conversely, the abundance of several putative hydrocarbonoclastic fungal OTUs was higher in the reduced pH–oil treatment. Sediment hydrocarbon profiling, furthermore, revealed higher concentrations of several alkanes in the reduced pH–oil treatment, corroborating the functional implications of the structural changes to microbial community composition. Collectively, our results advance the understanding of the response of a complex microbial community to the interaction between reduced pH and anthropogenic pollution. In future acidified marine environments, oil hydrocarbon contamination may alter the typical mixotrophic and k‐/r‐strategist composition of surface sediment microbiomes towards a more heterotrophic state with lower doubling rates, thereby impairing the ability of the ecosystem to recover from acute oil contamination events.     

Production and characterization of a thermostable glucoamylase from Streptosporangium sp. endophyte of maize leaves

Thermostable amylolytic enzymes are currently investigated to improve industrial processes of starch degradation. Streptosporangium sp. an endophytic actinomycete isolated from leaves of maize (Zea mays L.) showed glucoamylase production, using starch-Czapek medium, and the highest rate was obtained in the initial growth phase, after incubation for 24 h at pH 8.0. Maximum glucoamylase activity (158 U mg(-1) protein) was obtained at pH 4.5 and 70 degrees C. The isolated enzyme exhibited thermostable properties as indicated by retention of 100% of residual activity at 70 degrees C for 30 min with total inhibition at 100 degrees C. Extracellular enzyme from Streptosporangium sp. was purified by fractionated precipitation with ammonium sulphate. After 60% saturation produced 421 U mg(-1) protein, and yield was 74% with purification 2.7 fold. The enzyme produced by Streptosporangium sp. has potential for industrial applications.     

Colitis induced by proteinase-activated receptor-2 agonists is mediated by a neurogenic mechanism

Proteinase-activated receptor-2 (PAR2) activation induces colonic inflammation by an unknown mechanism. We hypothesized that PAR2 agonists administered intracolonically in mice induce inflammation via a neurogenic mechanism. Pretreatment of mice with neurokinin-1 and calcitonin-gene-related peptide (CGRP) receptor antagonists or with capsaicin showed attenuated PAR2-agonist-induced colitis. Immunohistochemistry demonstrated a differential expression of a marker for the type-1 CGRP receptor during the time course of PAR2-agonist-induced colitis, further suggesting a role for CGRP. We conclude that PAR2-agonist-induced intestinal inflammation involves the release of neuropeptides, which by acting on their receptors cause inflammation. These results implicate PAR2 as an important mediator of intestinal neurogenic inflammation.     

A new species of <Emphasis Type="Italic">Isospora</Emphasis> Schneider, 1881 (Apicomplexa: Eimeriidae) from the twist-necked turtle <Emphasis Type="Italic">Platemys platycephala</Emphasis> (Schneider) (Testudines: Chelidae) in Brazil

A new coccidian species of the genus Isospora Schneider 1881 (Apicomplexa, Eimeriidae) is reported from a single specimen of chelid turtle, Platemys platycephala (Schneider, 1792), obtained in a flooded area of the Amazonian municipality of Altamira, in Pará State, northern Brazil. The oöcysts of Isospora platemysi n. sp. are subspheroidal, 19.0–24.0 × 22.5–18.5 (22.6 × 20.8) µm in size [length/width ratio 1.0–1.1 (1.1)], with a colourless wall, 1.0–1.9 (1.4) wide, with two smooth layers; polar granule is present, oöcyst residuum and micropyle are both absent. The sporocyst is ovoidal, 10.0–12.1 × 8.0–10.0 (11.0 × 9.1) µm [length/width ratio 1.1–1.3 (1.2), with a knob-like Stieda body. Sub-Stieda body is present, rounded irregular-trapezoidal; para-Stieda body is absent. Sporocyst residuum is dispersed and composed of granules of differing sizes. This is only the fifth record of Isospora in chelonians, and the first report of a coccidian parasite of the genus Platemys.     

Differentially expressed proteins associated with drought tolerance in bananas (<Emphasis Type="Italic">Musa</Emphasis> spp.)

Bananas are one of the most important fruits in tropical and subtropical regions worldwide. Each year, banana plantations expand, but the areas available are mostly dry lands. The establishment of strategies for obtaining drought tolerant cultivars depends on understanding of biological responses at genetic, molecular and biochemical levels. Proteomics is a powerful tool for functional characterization of the response of plants to abiotic stress and little is known about drought tolerance in Musa spp. Therefore, the aim of this study was to identify proteins related to drought tolerance in two contrasting banana genotypes, Prata Anã and BRS Tropical, susceptible and tolerant to drought, respectively. Proteins were extracted from rhizomes of bananas grown under greenhouse conditions with control, irrigated and water deficit regimes. The differential protein expression pattern was established by two-dimensional (2-D) electrophoresis and spots analyzed in nano Q-Tof Micro UPLC. Twenty-three differentially expressed proteins were found in the tolerant genotype (BRS Tropical) under water deficit, with proteins involved in metabolism, defense and transport. Proteins were classified according to known function and biosynthetic pathways. Signaling proteins in response to water stress, especially for the biological function of growth and development of plants cells, were also encountered, whereas heat shock proteins played a significant role. This is the first report of proteomic analysis for drought tolerance in ‘Pome’ and ‘Silk-type’ bananas containing the ‘B’ genome. Our work provides insights into Musa spp. response to drought and data for further studies regarding molecular mechanisms, which determine how Musa spp. cells better overcome environmental perturbations.     

A gradient of gap junctional communication along the anterior-posterior axis of the developing chick limb bud.

A modification of the scrape-loading/dye transfer technique was used to study gap junctional communication along the anterior-posterior (A-P) axis of embryonic chick wing buds at an early stage of development (stage 20/21) when positional values along the A-P axis are being specified. Extensive intercellular transfer of the gap junction-permeable dye, lucifer yellow, from scrape-loaded mesenchymal cells to contiguous cells occurs in the posterior mesenchymal tissue of the wing bud adjacent to the zone of polarizing activity, which is thought to be the source of a diffusible morphogen that specifies A-P positional identity according to its local concentration. Considerably less transfer of lucifer yellow dye occurs in scrape-loaded mesenchymal tissue in the middle of the limb bud compared to posterior mesenchymal tissue, and little or no transfer of lucifer yellow is observed in the mesenchymal tissue in the anterior portion of the limb bud. No intercellular transfer of the gap junction-impermeable dye, rhodamine dextran, occurs in any region of the limb bud. These results indicate that there is a gradient of gap junctional communication along the A-P axis of the developing chick wing bud. This gradient of gap junctional communication along the A-P axis might generate a graded distribution of a relatively low molecular weight intracellular regulatory molecule involved in specifying A-P positional identities.     

Effects of Angular Leaf Spot and Rust on Leaf Gas Exchange and Yield of Common Bean (Phaseolus Vulgaris)

Isolated and interactive effects of angular leaf spot (caused by Phaeoisariopsis griseola) and rust (caused by Uromyces appendiculatus) on leaf gas exchange and yield was studied in common bean (Phaseolus vulgaris L. cv. Carioca) plants. Gas exchange was measured on 37, 44, 51, and 58 d after planting using a portable photosynthesis system. The inoculation of plants with P. griseola (P), U. appendiculatus (U), and the combination of both pathogens (P+U) caused a significant reduction of net photosynthetic rate (P _N) and yield. The reduction of stomatal conductance (g _s), P _N, and yield was higher under P and combination of P+U than under U treatment. By effect of U, the reduction on yield was higher than the reductions on gas exchange parameters. On the treatment P+U, a reduction of 23 % in P _N and a correspondent reduction of 32 % in yield was observed. The interactive effects of the pathogens on yield could be explained in part by the decreases in g _s and in P _N of diseased bean leaves. The combined effect of both diseases on yield and gas exchange parameters suggests an antagonistic interaction.     

Identification of conformational B-cell Epitopes in an antigen from its primary sequence

Background

One of the major challenges in the field of vaccine design is to predict conformational B-cell epitopes in an antigen. In the past, several methods have been developed for predicting conformational B-cell epitopes in an antigen from its tertiary structure. This is the first attempt in this area to predict conformational B-cell epitope in an antigen from its amino acid sequence.

Results

All Support vector machine (SVM) models were trained and tested on 187 non-redundant protein chains consisting of 2261 antibody interacting residues of B-cell epitopes. Models have been developed using binary profile of pattern (BPP) and physiochemical profile of patterns (PPP) and achieved a maximum MCC of 0.22 and 0.17 respectively. In this study, for the first time SVM model has been developed using composition profile of patterns (CPP) and achieved a maximum MCC of 0.73 with accuracy 86.59%. We compare our CPP based model with existing structure based methods and observed that our sequence based model is as good as structure based methods.

Conclusion

This study demonstrates that prediction of conformational B-cell epitope in an antigen is possible from is primary sequence. This study will be very useful in predicting conformational B-cell epitopes in antigens whose tertiary structures are not available. A web server CBTOPE has been developed for predicting B-cell epitope http://www.imtech.res.in/raghava/cbtope/.