Impairment of reproduction in the red flour beetle, Tribolium castaneum (Herbst) (Col., Tenebrionidae) due to larval feeding on triflumuron-treated diet

The larvae of Tribolium castaneum (Herbst) of different ages were exposed to various concentrations viz., 0.0001, 0.001 and 0.01 ppm of triflumuron up to pupation. The adults were allowed to feed on untreated diet. The preoviposition period, fecundity, egg viability and incubation period of the eggs laid were studied. Triflumuron significantly lengthened the preoviposition and incubation periods (P < 0.001). Fecundity and egg viability were also reduced (P < 0.001) due to the treatment. Both the strains were affected by the treatment.     

A novel chimeric peptide with antimicrobial activity

Beta‐lactamase‐mediated bacterial drug resistance exacerbates the prognosis of infectious diseases, which are sometimes treated with co‐administration of beta‐lactam type antibiotics and beta‐lactamase inhibitors. Antimicrobial peptides are promising broad‐spectrum alternatives to conventional antibiotics in this era of evolving bacterial resistance. Peptides based on the Ala46–Tyr51 beta‐hairpin loop of beta‐lactamase inhibitory protein (BLIP) have been previously shown to inhibit beta‐lactamase. Here, our goal was to modify this peptide for improved beta‐lactamase inhibition and cellular uptake. Motivated by the cell‐penetrating pVEC sequence, which includes a hydrophobic stretch at its N‐terminus, our approach involved the addition of LLIIL residues to the inhibitory peptide N‐terminus to facilitate uptake. Activity measurements of the peptide based on the 45–53 loop of BLIP for enhanced inhibition verified that the peptide was a competitive beta‐lactamase inhibitor with a K_i value of 58 μM. Incubation of beta‐lactam‐resistant cells with peptide decreased the number of viable cells, while it had no effect on beta‐lactamase‐free cells, indicating that this peptide had antimicrobial activity via beta‐lactamase inhibition. To elucidate the molecular mechanism by which this peptide moves across the membrane, steered molecular dynamics simulations were carried out. We propose that addition of hydrophobic residues to the N‐terminus of the peptide affords a promising strategy in the design of novel antimicrobial peptides not only against beta‐lactamase but also for other intracellular targets. Copyright © 2015 European Peptide Society and John Wiley & Sons, Ltd.     

Habitat Characteristics of the Endangered Hoolock Gibbons of Bangladesh: The Role of Plant Species Richness

Hoolock gibbons ( Hoolock hoolock ) are endangered small apes occurring in Bangladesh, India, Myanmar, and south China. All known populations have undergone declines primarily due to habitat destruction or alteration. We examined the influence of area of natural forests, area of plantations, area of agricultural land and edible plant species richness on the hoolock gibbon numbers from 22 sites in Bangladesh using multiple regression analysis. Area of natural forests and plantations were not linked to hoolock gibbon numbers, whereas area of agricultural land and edible plant species richness were both significantly linked. Higher edible plant species richness was directly related to hoolock gibbon numbers, while the area of agricultural land was inversely related. This is the first quantitative study illustrating the importance of these two variables with hoolock gibbon numbers. We also analyzed the existing habitat characteristics in two of the largest hoolock gibbon populations in Bangladesh: Lawachara (42 individuals) and Kaptai (84 individuals). Trees in Lawachara were generally smaller compared to those in Kaptai. Artocarpus , Tectona , and Dipterocarpus were the three most important genera in both sites, although Artocarpus was more important in Lawachara. Each site also had an abundant variety of tree species utilized by hoolock gibbons for food. We discuss the current context of primate conservation in Bangladesh and suggest that the current conservation priority for gibbons in the country should be protection and improvement of habitat.     

Proteome changes associated with hippocampal MRI abnormalities in the lithium pilocarpine-induced model of convulsive status epilepticus

Convulsive status epilepticus is associated with subsequent hippocampal damage and development of mesial temporal sclerosis in a subset of individuals. The lithium pilocarpine model of status epilepticus (SE) in the rat provides a model in which to investigate the molecular and pathogenic process leading to hippocampal damage. In this study, a 2-DE-based approach was used to detect proteome changes in the hippocampus, at an early stage (2 days) after SE, when increased T2 values were detectable by magnetic resonance imaging. Gel image analysis was followed by LC-MS/MS identification of protein species that differed in abundance between pilocarpine-treated and control rats. The most significantly up-regulated species in the experimental animals was identified as heat shock 27-kDa protein, in line with findings in humans and in other experimental models of epilepsy. Additional up-regulated species included dihydropyrimidinase-related protein-2, cytoskeletal proteins (alpha-tubulin and ezrin) and dihydropteridine reductase. In summary, the hippocampus of rats subject to pilocarpine-induced SE exhibits specific changes in protein abundance, which likely relate to pathogenic, neuroprotective and neurogenic responses.     

Prediction of cyclin-dependent kinase phosphorylation substrates

Protein phosphorylation, mediated by a family of enzymes called cyclin-dependent kinases (Cdks), plays a central role in the cell-division cycle of eukaryotes. Phosphorylation by Cdks directs the cell cycle by modifying the function of regulators of key processes such as DNA replication and mitotic progression. Here, we present a novel computational procedure to predict substrates of the cyclin-dependent kinase Cdc28 (Cdk1) in the Saccharomyces cerevisiae. Currently, most computational phosphorylation site prediction procedures focus solely on local sequence characteristics. In the present procedure, we model Cdk substrates based on both local and global characteristics of the substrates. Thus, we define the local sequence motifs that represent the Cdc28 phosphorylation sites and subsequently model clustering of these motifs within the protein sequences. This restraint reflects the observation that many known Cdk substrates contain multiple clustered phosphorylation sites. The present strategy defines a subset of the proteome that is highly enriched for Cdk substrates, as validated by comparing it to a set of bona fide, published, experimentally characterized Cdk substrates which was to our knowledge, comprehensive at the time of writing. To corroborate our model, we compared its predictions with three experimentally independent Cdk proteomic datasets and found significant overlap. Finally, we directly detected in vivo phosphorylation at Cdk motifs for selected putative substrates using mass spectrometry.     

IL-17-mediated regulation of innate and acquired immune response against pulmonary Mycobacterium bovis bacille Calmette-Guerin infection

IL-17 is a cytokine that induces neutrophil-mediated inflammation, but its role in protective immunity against intracellular bacterial infection remains unclear. In the present study, we demonstrate that IL-17 is an important cytokine not only in the early neutrophil-mediated inflammatory response, but also in T cell-mediated IFN-gamma production and granuloma formation in response to pulmonary infection by Mycobacterium bovis bacille Calmette-Guérin (BCG). IL-17 expression in the BCG-infected lung was detected from the first day after infection and the expression depended on IL-23. Our observations indicated that gammadelta T cells are a primary source of IL-17. Lung-infiltrating T cells of IL-17-deficient mice produced less IFN-gamma in comparison to those from wild-type mice 4 wk after BCG infection. Impaired granuloma formation was also observed in the infected lungs of IL-17-deficient mice, which is consistent with the decreased delayed-type hypersensitivity response of the infected mice against mycobacterial Ag. These data suggest that IL-17 is an important cytokine in the induction of optimal Th1 response and protective immunity against mycobacterial infection.     

Genomic Selection and Association Mapping in Rice (Oryza sativa): Effect of Trait Genetic Architecture,Training Population Composition,Marker Number and Statistical Model on Accuracy of Rice Genomic Selection in Elite,Tropical Rice Breeding Lines

Genomic Selection (GS) is a new breeding method in which genome-wide markers are used to predict the breeding value of individuals in a breeding population. GS has been shown to improve breeding efficiency in dairy cattle and several crop plant species, and here we evaluate for the first time its efficacy for breeding inbred lines of rice. We performed a genome-wide association study (GWAS) in conjunction with five-fold GS cross-validation on a population of 363 elite breeding lines from the International Rice Research Institute''s (IRRI) irrigated rice breeding program and herein report the GS results. The population was genotyped with 73,147 markers using genotyping-by-sequencing. The training population, statistical method used to build the GS model, number of markers, and trait were varied to determine their effect on prediction accuracy. For all three traits, genomic prediction models outperformed prediction based on pedigree records alone. Prediction accuracies ranged from 0.31 and 0.34 for grain yield and plant height to 0.63 for flowering time. Analyses using subsets of the full marker set suggest that using one marker every 0.2 cM is sufficient for genomic selection in this collection of rice breeding materials. RR-BLUP was the best performing statistical method for grain yield where no large effect QTL were detected by GWAS, while for flowering time, where a single very large effect QTL was detected, the non-GS multiple linear regression method outperformed GS models. For plant height, in which four mid-sized QTL were identified by GWAS, random forest produced the most consistently accurate GS models. Our results suggest that GS, informed by GWAS interpretations of genetic architecture and population structure, could become an effective tool for increasing the efficiency of rice breeding as the costs of genotyping continue to decline.     

Nematicidal Triterpenoids from Lantana camara

A new triterpene, lancamarolide ( 1 ), and seven known triterpenes, oleanonic acid ( 2 ), lantadene A ( 3 ), 11α‐hydroxy‐3‐oxours‐12‐en‐28‐oic acid ( 4 ), betulinic acid ( 5 ), lantadene B ( 6 ), and lantaninilic acid ( 7 ) were isolated from the aerial parts of Lantana camara in the course of bioassay‐guided isolation, and their nematicidal activities against Meloidogyne incognita, the root knot nematode, were carried out. Oleanonic acid was found to be the most active compound and exhibited 80% mortality after 72 h at 0.0625% concentration, which is comparable with that of the standard furadan.     

Computational Docking Study of p7 Ion Channel from HCV Genotype 3 and Genotype 4 and Its Interaction with Natural Compounds

Background

The current standard care therapy for hepatitis C virus (HCV) infection consists of two regimes, namely interferon-based and interferon-free treatments. The treatment through the combination of ribavirin and pegylated interferon is expensive, only mildly effective, and is associated with severe side effects. In 2011, two direct-acting antiviral (DAA) drugs, boceprevir and telaprevir, were licensed that have shown enhanced sustained virologic response (SVR) in phase III clinical trial, however, these interferon-free treatments are more sensitive to HCV genotype 1 infection. The variable nature of HCV, and the limited number of inhibitors developed thus aim in expanding the repertoire of available drug targets, resulting in targeting the virus assembly therapeutically.

Aim

We conducted this study to predict the 3D structure of the p7 protein from the HCV genotypes 3 and 4. Approximately 63 amino acid residues encoded in HCV render this channel sensitive to inhibitors, making p7 a promising target for novel therapies. HCV p7 protein forms a small membrane known as viroporin, and is essential for effective self-assembly of large channels that conduct cation assembly and discharge infectious virion particles.

Method

In this study, we screened drugs and flavonoids known to disrupt translation and production of HCV proteins, targeted against the active site of p7 residues of HCV genotype 3 (GT3) (isolatek3a) and HCV genotype 4a (GT4) (isolateED43). Furthermore, we conducted a quantitative structure–activity relationship and docking interaction study.

Results

The drug NB-DNJ formed the highest number of hydrogen bond interactions with both modeled p7 proteins with high interaction energy, followed by BIT225. A flavonoid screen demonstrated that Epigallocatechin gallate (EGCG), nobiletin, and quercetin, have more binding modes in GT3 than in GT4. Thus, the predicted p7 protein molecule of HCV from GT3 and GT4 provides a general avenue to target structure-based antiviral compounds.

Conclusions

We hypothesize that the inhibitors of viral p7 identified in this screen may be a new class of potent agents, but further confirmation in vitro and in vivo is essential. This structure-guided drug design for both GT3 and GT4 can lead to the identification of drug-like natural compounds, confirming p7 as a new target in the rapidly increasing era of HCV.