Transcriptome analysis and systemic RNAi response in the African sweetpotato weevil (Cylas puncticollis, Coleoptera, Brentidae

<div><p>The African sweetpotato weevil (SPW) <i>Cylas puncticollis</i> Boheman is one of the most important constraints of sweetpotato production in Sub-Saharan Africa and yet is largely an uncharacterized insect pest. Here, we report on the transcriptome analysis of SPW generated using an Illumina platform. More than 213 million sequencing reads were obtained and assembled into 89,599 contigs. This assembly was followed by a gene ontology annotation. Subsequently, a transcriptome search showed that the necessary RNAi components relevant to the three major RNAi pathways, were found to be expressed in SPW. To address the functionality of the RNAi mechanism in this species, dsRNA was injected into second instar larvae targeting <i>laccase2</i>, a gene which encodes an enzyme involved in the sclerotization of insect exoskeleton. The body of treated insects showed inhibition of sclerotization, leading eventually to death. Quantitative Real Time PCR (qPCR) confirmed this phenotype to be the result of gene silencing. Together, our results provide valuable sequence data on this important insect pest and demonstrate that a functional RNAi pathway with a strong and systemic effect is present in SPW and can further be explored as a new strategy for controlling this important pest.</p></div

Ferulic acid-4-O-sulfate rather than ferulic acid relaxes arteries and lowers blood pressure in mice

Consumption of foods rich in ferulic acid (FA) such as wholegrain cereals, or FA precursors such as chlorogenic acids in coffee, is inversely correlated with risk of cardiovascular disease and type 2 diabetes. As a result of digestion and phase II metabolism in the gut and liver, FA is converted predominantly into ferulic acid-4-O-sulfate (FA-sul), an abundant plasma metabolite. Although FA-sul may be the main metabolite, very little has been reported regarding its bioactivities. We have therefore compared the ex vivo vasorelaxing effect of FA and FA-sul (10−7 - 3.10−5 M) on isolated mouse arteries mounted in tissue myographs. FA-sul, but not FA, elicited a concentration-dependent vasorelaxation of saphenous and femoral arteries and aortae. The FA-sul mediated vasorelaxation was blunted by 1H- [1, 2, 4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a soluble guanylate cyclase (sGC) inhibitor. The role of sGC was confirmed in femoral arteries isolated from sGCα1(−/−) knockout mice. Furthermore, 4-aminopyridine, a specific inhibitor of voltage-dependent potassium channels, significantly decreased FA-sul mediated effects. In anesthetized mice, intravenous injection of FA-sul decreased mean arterial pressure, whereas FA had no effect, confirming the results obtained ex vivo. FA-sul is probably one of the major metabolites accounting for the blood pressure-lowering effects associated with FA consumption

Bumblebee resilience to climate change, through plastic and adaptive responses

peer reviewe

Capacidade de paras¡tismo de Telenomus podisi em ovos de Euschistus heros tratados com ¡nseticidas.

Conteúdo do volume 2: Ácaros; Biologia, fisiologia, morfologia; Controle biológico com bactérias entomopatogênicas; Controle biológico com fungos entomopatológicos; Controle biológico com nematoides; Controle biológico com parasitoides; Controle biológico com predadores; Ecologia e biodiversidade; Educação e etnoentomologia; Entomologia florestal; Entomologia Forense; Entomologia médica e veterinária; Entomologia molecular; Manejo integrado de pragas; Organismos geneticamente modificados; Plantas inseticidas; Polinização; Pragas quarentenárias e invasivas; Resistência de insetos a táticas de controle; Resistência de plantas a insetos; Semioquímicos e comportamento; Sistemática e taxonomia; Tecnologia de aplicação; Controle biológico com vírus entomopatogênicos; Controle químico

The genomes of two key bumblebee species with primitive eusocial organization

Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

Structural Basis for Specificity of Propeptide-Enzyme Interaction in Barley C1A Cysteine Peptidases

C1A cysteine peptidases are synthesized as inactive proenzymes. Activation takes place by proteolysis cleaving off the inhibitory propeptide. The inhibitory capacity of propeptides from barley cathepsin L and B-like peptidases towards commercial and barley cathepsins has been characterized. Differences in selectivity have been found for propeptides from L-cathepsins against their cognate and non cognate enzymes. Besides, the propeptide from barley cathepsin B was not able to inhibit bovine cathepsin B. Modelling of their three-dimensional structures suggests that most propeptide inhibitory properties can be explained from the interaction between the propeptide and the mature cathepsin structures. Their potential use as biotechnological tools is discussed

Contribution of Pollinator-Mediated Crops to Nutrients in the Human Food Supply

The contribution of nutrients from animal pollinated world crops has not previously been evaluated as a biophysical measure for the value of pollination services. This study evaluates the nutritional composition of animal-pollinated world crops. We calculated pollinator dependent and independent proportions of different nutrients of world crops, employing FAO data for crop production, USDA data for nutritional composition, and pollinator dependency data according to Klein et al. (2007). Crop plants that depend fully or partially on animal pollinators contain more than 90% of vitamin C, the whole quantity of Lycopene and almost the full quantity of the antioxidants β-cryptoxanthin and β-tocopherol, the majority of the lipid, vitamin A and related carotenoids, calcium and fluoride, and a large portion of folic acid. Ongoing pollinator decline may thus exacerbate current difficulties of providing a nutritionally adequate diet for the global human population