Prey location by Oechalia schellembergii

A total of 548 spiders (Gnaphosidae, Clubionidae, Thomisidae, Philodromidae, Salticidae, Lycosidae, Pisauridae, Linyphiidae) from three sand dune grassland sites were tested serologically for feeding on the grasshoppers, Chorthippus brunneus (Thunberg) and Myrmeleotettix maculatus (Thunberg). Lycosidae were the most commonly tested species and gave the greatest proportion of positive tests. Laboratory observations suggest that predation in the field was predominantly on first instar grasshoppers.

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Résumé Afin d'améliorer la connaissance de l'importance des prédateurs dans la biologie des populations de criquets (Orthoptères; Acrididae), les araignées de trois pelouses sur dunes de sable ont été examinées sérologiquement pour estimer leur consommation des populations sympatriques de Chorthippus brunneus Thunberg et Myrmeleotettix maculatus Thunberg. Au total, 548 araignées (Gnaphosidae, Clubionidae, Thomisidae, Philodromidae, Salticidae, Lycosidae, Pisauridae, Linyphiidae) ont été récoltées à la main ou par piège pendant la période d'éclosion des ufs de criquets. Les Lycosidae ont été le plus fréquemment observées (90,5% de toutes les récoltes) et ont donné la plus forte proportion d'individus positifs (jusqu'à 32,3%). Les expériences d'alimentation en laboratoire suggèrent que, dans la nature, les Lycosidae sont les plus actives contre les criquets du premier stade.

     

Macrophylloside, a flavone glucoside from Primula macrophylla

A new flavone glucoside macrophylloside has been isolated from the whole plant of Primula macrophylla and its structure was determined by spectroscopic methods as 2′-hydroxy-7-O-β- -glucopyranosyloxyflavone. Sitosterol glucoside was also isolated for the first time from this plant.     

Predation by three hemipterans:Tropiconabis nigrolineatus,Oechalia schellenbergii andCermatulus nasalis,onHeliothis punctiger larvae in two types of searching arenas

Three species of hemipteran predators preyed differently upon 1^st instarHeliothis punctiger Wallengren larvae.Cermatulus nasalis consumed more larvae thanOechalia schellenbergii which consumed more larvae thanTropiconabis nigrolineatus. All the species consumed significantly less 1^st instar larvae on plants than what they consumed in Petri-dishes. Fifth instar predators showed significant differences in terms of prey consumption due to sex independent of searching conditions. Only 4^th and 5^th instars ofT. nigrolineatus attacked and captured 2^nd instars ofH. punctiger larvae. The other 2 species however readily attacked and consumed 2^nd instarH. punctiger larvae. Their prey consumption was similar in Petri-dishes and on plants. Only 5^th instars ofT. nigrolineatus could subdue and capture 3^rd instarH. punctiger larvae. Second instar pentatomids captured just one 3^rd instar larva but older instars killed and ate more. Fourth instarH. punctiger larvae were immune to attacks by allT. nigrolineatus and younger pentatomids due to their defense ploys but 5^th instar pentatomids could subdue and capture them. None of the predators captured 5^th instarH. punctiger larvae except few 5^th instar females ofC. naslis andO. schellenbergii.      

Interaction of maternal environment and allelic differences in seed vigour genes determines seed performance in Brassica oleracea

Seed vigour is a key trait essential for the production of sustainable and profitable crops. The genetic basis of variation in seed vigour has recently been determined in Brassica oleracea, but the relative importance of the interaction with parental environment is unknown. We produced seeds under a range of maternal environments, including global warming scenarios. Lines were compared that had the same genetic background, but different alleles (for high and low vigour) at the quantitative trait loci responsible for determining seed vigour by altering abscisic acid (ABA) content and sensitivity. We found a consistent effect of beneficial alleles across production environments; however, environmental stress during production also had a large impact that enhanced the genetic difference in seed performance, measured as germination speed, resistance to controlled deterioration and induction of secondary dormancy. Environmental interaction with allelic differences in key genes that determine ABA content and sensitivity develops a continuity in performance from rapid germination through to failure to complete germination, and increasing depths of seed dormancy. The genetic–environmental interaction revealed provides a robust mechanism of bet‐hedging to minimize environmental risk during subsequent germination, and this could have facilitated the rapid change in seed behaviour (reduced dormancy and rapid germination) observed during crop domestication.     

Expression levels of the metalloproteinase ADAM8 critically regulate proliferation,migration and malignant signalling events in hepatoma cells

Hepatocellular carcinoma (HCC) is one of the most common metastatic tumours. Tumour growth and metastasis depend on the induction of cell proliferation and migration by various mediators. Here, we report that the A Disintegrin and Metalloproteinase (ADAM) 8 is highly expressed in murine HCC tissues as well as in murine and human hepatoma cell lines Hepa1-6 and HepG2, respectively. To establish a dose-dependent role of different ADAM8 expression levels for HCC progression, ADAM8 expression was either reduced via shRNA- or siRNA-mediated knockdown or increased by using a retroviral overexpression vector. These two complementary approaches revealed that ADAM8 expression levels correlated positively with proliferation, clonogenicity, migration and matrix invasion and negatively with apoptosis of hepatoma cells. Furthermore, the analysis of pro-migratory and proliferative signalling pathways revealed that ADAM8 expression level was positively associated with expression of β1 integrin as well as with the activation of focal adhesion kinase (FAK), mitogen-activated protein kinase (MAPK), Src kinase and Rho A GTPase. Finally, up-regulation of promigatory signalling and cell migration was also seen with a proteolytically inactive ADAM8 mutant. These findings reveal that ADAM8 is critically up-regulated in hepatoma cells contributes to cell proliferation and survival and furthermore induces pro-migratory signalling pathways independently of its proteolytic activity. By this, ADAM8 can promote cell functions most relevant for HCC growth and metastasis.     

Viral impacts on honey bee populations: A review

Honey bee is vital for pollination and ecological services, boosting crops productivity in terms of quality and quantity and production of colony products: wax, royal jelly, bee venom, honey, pollen and propolis. Honey bees are most important plant pollinators and almost one third of diet depends on bee’s pollination, worth billions of dollars. Hence the role that honey bees have in environment and their economic importance in food production, their health is of dominant significance. Honey bees can be infected by various pathogens like: viruses, bacteria, fungi, or infested by parasitic mites. At least more than 20 viruses have been identified to infect honey bees worldwide, generally from Dicistroviridae as well as Iflaviridae families, like ABPV (Acute Bee Paralysis Virus), BQCV (Black Queen Cell Virus), KBV (Kashmir Bee Virus), SBV (Sacbrood Virus), CBPV (Chronic bee paralysis virus), SBPV (Slow Bee Paralysis Virus) along with IAPV (Israeli acute paralysis virus), and DWV (Deformed Wing Virus) are prominent and cause infections harmful for honey bee colonies health. This issue about honey bee viruses demonstrates remarkably how diverse this field is, and considerable work has to be done to get a comprehensive interpretation of the bee virology.     

Extracellular biosynthesis,characterization, optimization of silver nanoparticles (AgNPs) using Bacillus mojavensis BTCB15 and its antimicrobial activity against multidrug resistant pathogens

Abstract

Biosynthesis of metal nanoparticles is an area of interest among researchers because of its eco-friendly approach. Current study focuses at biosynthesis of silver nanoparticles (AgNPs) and optimization of physico-chemical conditions to obtain mono-dispersed and stable AgNPs having antimicrobial activity. Initially Bacillus mojavensis BTCB15 produced silver nanoparticles (AgNPs) of 105?nm. Silver nanoparticles (AgNPs) were characterized by particle size analyzer, UV-Vis Spectroscopy, Fourier transforms infrared spectroscopy (FTIR), Atomic force microscopy (AFM), and X-ray diffraction (XRD). Whereas, under optimal conditions of temperature 55?°C, pH 8, addition of surfactant Tween 20, and metal ion K₂SO₄, about 104% size reduction was achieved with average size of 2.3nm. Molecular characterization revealed 98% sequence homology with Bacillus mojavensis. AgNPs exhibited antibacterial activity at concentrations ranging from 0.5 to 2.5?µg/µl against Escherichia coli BTCB03, Klebsiella pneumonia BTCB04, Acinetobacter sp. BTCB05, and Pseudomonas aeruginosa BTCB01 but none against Staphylococcus aureus BTCB02. Highest antibacterial activity was observed at 0.27?µg/µl and lowest at 0.05?µg/µl of AgNPs indicated by zone of inhibition. Conclusively, under optimum conditions, Bacillus mojavensis BTCB15 was able to produce AgNPs of 2.3?nm size and had antibacterial activity against multi drug resistant pathogens.