Workers of the primitively eusocial wasp <Emphasis Type="Italic">Ropalidia marginata</Emphasis> do not perceive their queen across a wire mesh partition

Queens of primitively eusocial wasps generally have active and behaviourally dominant queens who use physical aggression to suppress worker reproduction. Although a Ropalidia marginata queen is strikingly docile and behaviourally non-dominant, she is completely successful in maintaining reproductive monopoly. R. marginata queens must achieve such reproductive monopoly by some means other than overt physical aggression. Upon loss or removal of the queen, one of the workers (referred to as the potential queen) becomes extremely aggressive and will eventually go on to become the next queen of the colony, if the original queen is not returned. The fact that potential queens are not discernible in the presence of the queen but become obvious within minutes after removal of the queen raises the question of how workers in general and the potential queens in particular, perceive the presence or absence of their queens. Here, we have conducted experiments in which we separate half of the workers from their queen by a wire mesh screen and study their behavioural response to such separation. We demonstrate that the presence of the queen is not perceived across the wire mesh screen, which suggests that if the queen uses a pheromone to signal her presence, then that pheromone is not very volatile.     

YacG from Escherichia coli is a specific endogenous inhibitor of DNA gyrase

We assign a function for a small protein, YacG encoded by Escherichia coli genome. The NMR structure of YacG shows the presence of an unusual zinc-finger motif. YacG was predicted to be a part of DNA gyrase interactome based on protein-protein interaction network. We demonstrate that YacG inhibits all the catalytic activities of DNA gyrase by preventing its DNA binding. Topoisomerase I and IV activities remain unaltered in the presence of YacG and its action appears to be restricted only to DNA gyrase. The inhibition of the enzyme activity is due to the binding of YacG to carboxyl terminal domain of GyrB. Overexpression of YacG results in growth inhibition and alteration in DNA topology due to uncontrolled inhibition of gyrase.     

Minimizing Variability of Cascade Impaction Measurements in Inhalers and Nebulizers

The purpose of this article is to catalogue in a systematic way the available information about factors that may influence the outcome and variability of cascade impactor (CI) measurements of pharmaceutical aerosols for inhalation, such as those obtained from metered dose inhalers (MDIs), dry powder inhalers (DPIs) or products for nebulization; and to suggest ways to minimize the influence of such factors. To accomplish this task, the authors constructed a cause-and-effect Ishikawa diagram for a CI measurement and considered the influence of each root cause based on industry experience and thorough literature review. The results illustrate the intricate network of underlying causes of CI variability, with the potential for several multi-way statistical interactions. It was also found that significantly more quantitative information exists about impactor-related causes than about operator-derived influences, the contribution of drug assay methodology and product-related causes, suggesting a need for further research in those areas. The understanding and awareness of all these factors should aid in the development of optimized CI methods and appropriate quality control measures for aerodynamic particle size distribution (APSD) of pharmaceutical aerosols, in line with the current regulatory initiatives involving quality-by-design (QbD). Editorial Comment: The International Pharmaceutical Aerosol Consortium on Regulation and Science (IPAC-RS) is an international association of innovator and generic companies that develop, manufacture or market orally inhaled and nasal drug products for local and systemic treatment of a variety of debilitating diseases such as asthma, chronic obstructive pulmonary disease and diabetes. IPAC-RS is committed to advancing consensus-based, scientifically driven standards and regulations for these products, with the purpose of facilitating the availability of high-quality, safe, and efficacious drug products to patients.     

Efficacy of culture filtrates of <Emphasis Type="Italic">Metarhizium anisopliae</Emphasis> against larvae of <Emphasis Type="Italic">Anopheles stephensi</Emphasis> and <Emphasis Type="Italic">Culex quinquefasciatus</Emphasis>

Efficacy of culture filtrates of five strains of Metarhizium anisopliae isolated from insects were evaluated against Anopheles stephensi and Culex quinquefasciatus. The culture filtrates released from the strains of M. anisopliae in the YpSs and chitin broths were filtered and used for the bioassays after a growth of 7 days. Among the culture filtrates of five strains, M. anisopliae 892 was found to be more effective against both the mosquitoes. The LC(50) values of culture filtrates of M. anisopliae 892 in chitin broth was lower than the LC(50) of culture filtrates in YpSs broth against first and fourth instars of both the mosquitoes. The LC(50) values of culture filtrates were significantly different between first and fourth instars of A. stephensi (t test; P = 0.0001) and C. quinquefasciatus (t test; P = 0.02). The larvae of A. stephensi were more susceptible than C. quinquefasciatus except in two cases. This is the first report of efficacy of culture filtrates produced by M. anisopliae in chitin broth against mosquitoes and have potential as a biological control agent of mosquitoes.     

We know that the wasps 'know': cryptic successors to the queen in Ropalidia marginata

Unlike other primitively eusocial wasps, Ropalidia marginata colonies are usually headed by remarkably docile and behaviourally non-dominant queens who are nevertheless completely successful in maintaining reproductive monopoly. As in other species, loss of the queen results in one of the workers taking over as the next queen. But unlike in other species, here, the queen's successor cannot be predicted on the basis of dominance rank, other behaviours, age, body size or even ovarian development, in the presence of the former queen. But the swiftness with which one and only one individual becomes evident as the potential queen led us to suspect that there might be a designated successor to the queen known to the wasps, even though we cannot identify her in the queen's presence. Here, we present the results of experiments that support such a 'cryptic successor' hypothesis, and thereby lend credence to the idea that queen (and potential queen) pheromones act as honest signals of their fertility, in R. marginata.     

Comparative Analysis on the Effect of <Emphasis Type="Italic">Plantago</Emphasis> Species Aqueous Extracts on Tissue Trace Element Content in Rats

The interaction between iron and copper has been discussed in association with human health and diseases for many years. Ceruloplasmin, a multi-copper oxidase, is mainly involved in iron metabolism and its genetic defect, aceruloplasminemia (ACP), shows neurological disorders and diabetes associated with excessive iron accumulation, but little is known about the state of copper in the brain. Here, we investigated localization of these metals in the brains of three patients with ACP using electron microscopes equipped with an energy-dispersive x-ray analyzer. Histochemically, iron deposition was observed mainly in the basal ganglia and dentate nucleus, and to lesser degree in the cerebral cortex of the patients, whereas copper grains were not detected. X-ray microanalysis identified two types of iron-rich particles in their brains: dense bodies, namely hemosiderins, and their aggregated inclusions. A small number of hemosiderins and most inclusions contained a significant amount of copper which was enough for distinct Cu x-ray images. These copper-containing particles were observed more frequently in the putamen and dentate nucleus than the cerebral cortex. Coexistence of iron and copper was supported by good correlations in the molecular ratios between these two metals in iron-rich particles with Cu x-ray image. Iron-dependent copper accumulation in iron-rich particles may suggest that copper recycling is enhanced to meet the increased requirement of cuproproteins in iron overload brain. In conclusion, the iron-rich particles with Cu x-ray image were found in the ACP brain.     

Differential Effects of Intrauterine Growth Restriction on the Regional Neurochemical Profile of the Developing Rat Brain

Intrauterine growth restricted (IUGR) infants are at increased risk for neurodevelopmental deficits that suggest the hippocampus and cerebral cortex may be particularly vulnerable. Evaluate regional neurochemical profiles in IUGR and normally grown (NG) 7-day old rat pups using in vivo ¹H magnetic resonance (MR) spectroscopy at 9.4 T. IUGR was induced via bilateral uterine artery ligation at gestational day 19 in pregnant Sprague–Dawley dams. MR spectra were obtained from the cerebral cortex, hippocampus and striatum at P7 in IUGR (N = 12) and NG (N = 13) rats. In the cortex, IUGR resulted in lower concentrations of phosphocreatine, glutathione, taurine, total choline, total creatine (P < 0.01) and [glutamate]/[glutamine] ratio (P < 0.05). Lower taurine concentrations were observed in the hippocampus (P < 0.01) and striatum (P < 0.05). IUGR differentially affects the neurochemical profile of the P7 rat brain regions. Persistent neurochemical changes may lead to cortex-based long-term neurodevelopmental deficits in human IUGR infants.     

What signals do herbivore-induced plant volatiles provide conspecific herbivores?

Herbivore-induced plant volatiles (HIPVs) have been opined as ‘indirect or direct defenses’ of plants and are extensively studied. In contrast, HIPVs may also indicate that plant defenses have been overcome by herbivores infesting the plant; however, studies on this aspect have so far received little attention. Using the interaction of Capsicum annum (Bell pepper) with its pest Scirtothrips dorsalis (Chilli thrips) as a model system, we studied the role of HIPVs in this selected insect–plant interaction. Multiple-choice olfactometer assays with headspace volatiles collected from different growth stages of un-infested C. annum plants represented by pre-flowering (PF), flowering (FL) and fruiting stages (FR) proved FR volatiles to be highly attractive to S. dorsalis. Further, FR plants were infested with S. dorsalis adults and HIPVs released by infested plants were collected and subjected to multiple-choice olfactometer bioassays. Thrips were significantly attracted to HIPVs than to headspace volatiles of un-infested FR plants or thrips body odour. Coupled GC-EAG with S. dorsalis and HIPVs or FR plant volatile revealed specific compounds that elicited an EAG response. Individual EAG-active compounds were less attractive to thrips, however, synthetic blends of EAG-active compounds at the ratio similar to headspace samples were found to be highly attractive. However, when given a choice between synthetic blends of HIPVs and FR, thrips were significantly attracted to synthetic blend of HIPVs. Our study provides empirical data on signals HIPVs may provide to conspecific herbivores and suggests that the role of HIPVs, mostly generalized as defense, may vary based on the interaction and must be studied closely to understand their ecological functions.     

Exploring drought stress-regulated genes in senna (Cassia angustifolia Vahl.): a transcriptomic approach

Functional & Integrative Genomics - De novo assembly of reads produced by next-generation sequencing (NGS) technologies offers a rapid approach to obtain expressed gene sequences for non-model...