LuMPIS – A modified luminescence‐based mammalian interactome mapping pull‐down assay for the investigation of protein–protein interactions encoded by GC‐low ORFs

The GC content is highly variable among the genomes of different organisms. It has been shown that recombinant gene expression in mammalian cells is much more efficient when GC‐rich coding sequences of a certain protein are used. In order to study protein–protein interactions in Varicella zoster virus, a GC‐low herpesvirus, we have developed a novel luminescence‐based maltose‐binding protein pull‐down interaction screening system (LuMPIS) that is able to overcome the impaired protein expression levels of GC‐low ORFs in mammalian expression systems.     

(E)-2-Styrylchromones as potential anti-norovirus agents

Human noroviruses (NoV) are now recognized as the most frequent cause of outbreaks and sporadic cases of acute gastroenteritis. Despite the significant economic impact and considerable morbidity of norovirus disease, no drug or vaccine is currently available to treat or prevent this disease, therefore the discovery of anti-norovirus drugs is urgent.In the present work, a total of 12 structure related chromone and (E)-2-styrylchromones were evaluated for their potential anti-norovirus activity using the murine norovirus (MNV) as a surrogate model for human NoV.From the 12 compounds studied, six (E)-2-styrylchromones were found to have with interesting anti-norovirus activity. The best compounds of the series were (E)-5-hydroxy-2-styrylchromone and (E)-4′-methoxy-2-styrylchromone with an IC₅₀ ≈ 7 μM. A first insight into the mechanism of action of these compounds was possible. An interesting relationship between the anti-norovirus activity and the chemical structure was observed. The present study points out that the (E)-2-styrylchromones skeleton is an important one which deserves to be developed and further explored as new antiviral drugs against NoV.     

Genotoxic evaluation of the organophosphorous pesticide temephos

The chemical compound temephos (0,0,0',0'-tetrametyl-0,0'-thiodi-p-phenylene phosphorothioate) is an organophosphorous pesticide that has been used in Brazil since 1967 in control campaigns against the mosquito Aedes aegypti, the vector of dengue and yellow fever. We used single cell gel electrophoresis (SCGE), SOS/umu and Ames/Salmonella assays to test the toxicity and mutagenicity of temephos. Temephos was genotoxic in the SCGE assay, inducing severe DNA lesions (type IV lesions) at doses above 1.34 micro M. It was mutagenic, but not toxic, in the SOS/umu assay to Escherichia coli strain PQ37, but not to PQ35, at concentrations above 1.33 micro M, particularly when the S9 mixture was not used in the assay. Temephos was not mutagenic in the Ames assay with S. typhimurium strains TA97, TA98, TA100 and TA102, both with and without metabolic activation. However, temephos at concentrations above 3.33 micro M was mutagenic to TA98NR, YG7104 and YG7108, both with and without metabolic activation. In conclusion, temephos was genotoxic and mutagenic in all the three tests used, and in two of them at concentrations similar to those routinely used to combat Aedes aegypti.     

Correlation of the critical micelle concentrations of surfactants with their effects on a bacterial demethylase.

The activity of a sarcosine dehydrogenase isolated from a strain of Pseudomonas is enhanced by the addition of Triton X-100, Brij 35, and Tween 80, and is inhibited by deoxycholate and Sarkosyl NL-97. 2,6-Dichlorophenolindophenol, which is used as the oxidant in the dehydrogenase assay, has also been employed as an indicator in the spectrophotometric determination of the critical micelle concentrations (CMC) of both the nonionic and anionic detergents under conditions optimal for the enzyme analyses. A correlation between the activation or inhibitory activities of the surfactants and their CMC values has been established.     

Purification and molecular cloning of a new galactose-specific lectin from <Emphasis Type="Italic">Bauhinia variegata</Emphasis> seeds

A new galactose-specific lectin was purified from seeds of a Caesalpinoideae plant, Bauhinia variegata, by affinity chromatography on lactose-agarose. Protein extracts haemagglutinated rabbit and human erythrocytes (native and treated with proteolytic enzymes), showing preference for rabbit blood treated with papain and trypsin. Among various carbohydrates tested, the lectin was best inhibited by D-galactose and its derivatives, especially lactose. SDS-PAGE showed that the lectin, named BVL, has a pattern similar to other lectins isolated from the same genus, Bauhinia purpurea agglutinin (BPA). The molecular mass of BVL subunit is 32 871 Da, determined by MALDI-TOF spectrometry. DNA extracted from B. variegata young leaves and primers designed according to the B. purpurea lectin were used to generate specific fragments which were cloned and sequenced, revealing two distinct isoforms. The bvl gene sequence comprised an open reading frame of 876 base pairs which encodes a protein of 291 amino acids. The protein carried a putative signal peptide. The mature protein was predicted to have 263 amino acid residues and 28 963 Da in size.     

Stimulation of dopamine D1 receptor improves learning capacity in cooperating cleaner fish

Accurate contextual decision-making strategies are important in social environments. Specific areas in the brain are tasked to process these complex interactions and generate correct follow-up responses. The dorsolateral and dorsomedial parts of the telencephalon in the teleost fish brain are neural substrates modulated by the neurotransmitter dopamine (DA), and are part of an important neural circuitry that drives animal behaviour from the most basic actions such as learning to search for food, to properly choosing partners and managing decisions based on context. The Indo-Pacific cleaner wrasse Labroides dimidiatus is a highly social teleost fish species with a complex network of interactions with its ‘client’ reef fish. We asked if changes in DA signalling would affect individual learning ability by presenting cleaner fish two ecologically different tasks that simulated a natural situation requiring accurate decision-making. We demonstrate that there is an involvement of the DA system and D₁ receptor pathways on cleaners'' natural abilities to learn both tasks. Our results add significantly to the growing literature on the physiological mechanisms that underlie and facilitate the expression of cooperative abilities.     

Variations in the gonostyle of Nyssomyia intermedia (Lutz & Neiva) (Diptera: Psychodidae)

This paper describes sand flies similar to Nyssomyia intermedia (Lutz & Neiva) with variations in the number of spines at the gonostyle and tests the hypothesis whether these specimens belong or not to N. intermedia species. Using Principal Component Analysis and Neighbour Joining, the measurements of 15 structures of the phlebotomine with variations in number of spines were compared with measurements of 30 sand flies of N. intermedia species. Both analyses didn't cluster the specimens with variation in spines number in one group and provided evidence to the hypothesis that those sand flies belong to N. intermedia.     

Patterns of liana community diversity and structure in a tropical rainforest reserve,Ghana: effects of human disturbance

Most studies have concluded that liana diversity and structure increase with disturbance. However, a contradictory pattern has emerged recently calling for more research in the area. Liana diversity and structure were investigated in three forest types that differ in disturbance intensity (nondisturbed, moderately disturbed and heavily disturbed forest: NDF, MDF and HDF, respectively) in the Atewa Range Forest Reserve, Ghana. In each forest type, 10 square plots of 0.25 ha were demarcated. Lianas with diameter ≥1 cm located on trees with diameter ≥10 cm were enumerated. A total of 429 individuals representing 40 species, 29 genera and seventeen families were identified in the study. Shannon diversity and species richness of lianas were significantly lower in the HDF (P < 0.05). Liana density and basal area differed significantly across all forest types (P < 0.0001). The importance value index (IVI) of most liana species varied greatly across the forest types. The current study has provided evidence to support the pattern of decreasing liana diversity and structure with disturbance in some tropical forests. Further studies are recommended to gain more understanding of the factors that are responsible for the divergent liana responses to disturbance in tropical forests.     

Reducing boll weevil populations by clipping terminal buds and removing abscised fruiting bodies

Cotton pests damaging fruiting bodies (squares and young bolls) are difficult to control and their damage results in direct yield loss. Small growers, with low technological inputs, represent a large portion of cotton growers worldwide comprising more than 76 countries; they rely mainly on cultural practices to counteract pest attack in their crops. Boll weevil, Anthonomus grandis Boheman (Coleoptera: Curculionidae), oviposition involves puncturing cotton squares and young bolls, causing abscission. We examined the impact on boll weevil population of collecting abscised cotton fruiting bodies and clipping plant terminals at 50% boll maturation in the field during two cotton‐growing seasons and under field cage conditions. Greatest numbers of damaged squares occurred ca. 117 days after planting and clipped plants resulted in reduction of abscised structures and adult boll weevils compared with non‐clipped plants, irrespective of cotton variety. Damaged young bolls were found ca. 128 days after planting in 2009 and 2011, but clipping had no effect. Numbers of boll weevils found in plants of the varieties BRS 201 and BRS Rubi (both in 2009) and BRS Rubi (in 2011) were, respectively, 13‐, 17‐, and 20‐fold greater when clipping plus collecting abscised fruiting bodies were not practiced. Furthermore, the average percentage of the boll weevil parasitoid Bracon vulgaris Ashmead (Hymenoptera: Braconidae) emerging from abscised and collected structures was similar between clipped and non‐clipped plant terminals in both seasons. Clipping plant terminals did not result in yield reduction and reduced adult boll weevil production. Collecting abscised reproductive structures, clipping plant terminals, and using both practices together reduced boll weevil populations by as much as 63, 57, and 79%, respectively, in cage trials. Thus, these practices cause significant impact on boll weevil populations and are feasible of adoption, especially for smallholder cotton growers.