Effect of coconut palm proximities and Musa spp. germplasm resistance to colonization by Raoiella indica (Acari: Tenuipalpidae)

Although coconut (Cocos nucifera L.) is the predominant host for Raoiella indica Hirst (Acari: Tenuipalpidae), false spider mite infestations do occur on bananas and plantains (Musa spp. Colla). Since its introduction, the banana and plantain industries have been negatively impacted to different degrees by R. indica infestation throughout the Caribbean. Genetic resistance in the host and the proximity of natural sources of mite infestation has been suggested as two of the main factors affecting R. indica densities in Musa spp. plantations. Greenhouse experiments were established to try to determine what effect coconut palm proximities and planting densities had on R. indica populations infesting Musa spp. plants. Trials were carried out using potted Musa spp. and coconut palms plants at two different ratios. In addition, fourteen Musa spp. hybrid accessions were evaluated for their susceptibility/resistance to colonization by R. indica populations. Differences were observed for mite population buildup for both the density and germplasm accession evaluations. These results have potential implications on how this important pest can be managed on essential agricultural commodities such as bananas and plantains.     

α-Tocopherol regulates ectonucleotidase activities in synaptosomes from rats fed a high-fat diet

α-Tocopherol (α-Toc) is involved in various physiologic processes, which present antioxidant and neuroprotective properties. High-fat diets have an important role in neurodegenerative diseases and neurological disturbances. This study aimed to investigate the effects of treatment with α-Toc and the consumption of high-fat diets on ectonucleotidase activities in synaptosomes of cerebral cortex, hippocampus and striatum of rats. Animals were divided into four different groups, which received standard diet (control), high-fat saturated diet (HF), α-Toc and high-fat saturated diet plus α-Toc (α-Toc + HF). High-fat saturated diet was administered ad libitum and α-Toc by gavage using a dose of 50 mg·kg(-1). After 3 months of treatment, animals were submitted to euthanasia, and cerebral cortex, hippocampus and striatum were collected for biochemical assays. Results showed that adenosine triphosphate (ATP), adenosine diphosphate (ADP) and adenosine monophosphate (AMP) hydrolysis in the cerebral cortex, hippocampus and striatum were decreased in HF in comparison to the other groups (P < 0·05). When rats that received HF were treated with α-Toc, the activity of the ectonucleotidases was similar to the control. ATP, ADP and AMP hydrolysis in the cerebral cortex, hippocampus and striatum were increased in the α-Toc group when compared with the other groups (P < 0·05). These findings demonstrated that the HF alters the purinergic signaling in the nervous system and that the treatment with α-Toc was capable of modulating the adenine nucleotide hydrolysis in this experimental condition.     

Globotriaosylceramide is correlated with oxidative stress and inflammation in Fabry patients treated with enzyme replacement therapy

Fabry disease is an X-linked inborn error of glycosphingolipid catabolism due to deficient activity of α-galactosidase A that leads to accumulation of the enzyme substrates, mainly globotriaosylceramide (Gb3), in body fluids and lysosomes of many cell types. Some pathophysiology hypotheses are intimately linked to reactive species production and inflammation, but until this moment there is no in vivo study about it. Hence, the aim of this study was to investigate oxidative stress parameters, pro-inflammatory cytokines and Gb3 levels in Fabry patients under treatment with enzyme replacement therapy (ERT) and finally to establish a possible relation between them. We analyzed urine and blood samples of patients under ERT (n = 14) and healthy age-matched controls (n = 14). Patients presented decreased levels of antioxidant defenses, assessed by reduced glutathione (GSH), glutathione peroxidase (GPx) activity and increased superoxide dismutase/catalase (SOD/CAT) ratio in erythrocytes. Concerning to the damage to biomolecules (lipids and proteins), we found that plasma levels of malondialdehyde (MDA) and protein carbonyl groups and di-tyrosine (di-Tyr) in urine were increased in patients. The pro-inflammatory cytokines IL-6 and TNF-α were also increased in patients. Urinary Gb3 levels were positively correlated with the plasma levels of IL-6, carbonyl groups and MDA. IL-6 levels were directly correlated with di-Tyr and inversely correlated with GPx activity. This data suggest that pro-inflammatory and pro-oxidant states occur, are correlated and seem to be induced by Gb3 in Fabry patients.     

Skeletal development in the fossorial gymnophthalmids Calyptommatus sinebrachiatus and Nothobachia ablephara

The development of the cartilaginous and bony elements that form the skull and axial and appendicular skeleton is described in detail for the post-ovipositional embryonic development of the fossorial gymnophthalmid species Calyptommatus sinebrachiatus and Nothobachia ablephara. Both species have a snake-like morphology, showing an elongated body and reduced or absent limbs, as well as modifications in skull bones for burrowing, such as complex articulation surfaces and development of bony extensions that enclose and protect the brain. Similar morphological changes have originated independently in several squamate groups, including the one that led to the snake radiation. This study characterizes the patterns of chondrogenesis and osteogenesis, with special emphasis on the features associated with the burrowing habit, and may be used for future comparative analyses of the developmental patterns involved in the origin of the convergent serpentiform morphologies.     

Clustering biomolecular complexes by residue contacts similarity

Inaccuracies in computational molecular modeling methods are often counterweighed by brute-force generation of a plethora of putative solutions. These are then typically sieved via structural clustering based on similarity measures such as the root mean square deviation (RMSD) of atomic positions. Albeit widely used, these measures suffer from several theoretical and technical limitations (e.g., choice of regions for fitting) that impair their application in multicomponent systems (N > 2), large-scale studies (e.g., interactomes), and other time-critical scenarios. We present here a simple similarity measure for structural clustering based on atomic contacts--the fraction of common contacts--and compare it with the most used similarity measure of the protein docking community--interface backbone RMSD. We show that this method produces very compact clusters in remarkably short time when applied to a collection of binary and multicomponent protein-protein and protein-DNA complexes. Furthermore, it allows easy clustering of similar conformations of multicomponent symmetrical assemblies in which chain permutations can occur. Simple contact-based metrics should be applicable to other structural biology clustering problems, in particular for time-critical or large-scale endeavors.     

The methylation patterns of the IGF2 and IGF2R genes in bovine spermatozoa are not affected by flow-cytometric sex sorting

The objectives of this study were to investigate the effect of sexing by flow cytometry on the methylation patterns of the IGF2 and IGF2R genes. Frozen‐thawed, unsorted, and sex‐sorted sperm samples from four Nellore bulls were used. Each ejaculate was separated into three fractions: non‐sexed (NS), sexed for X‐sperm (SX), and sexed for Y‐sperm (SY). Sperm were isolated from the extender, cryoprotectant, and other cell types by centrifugation on a 40:70% Percoll gradient, and sperm pellets were used for genomic DNA isolation. DNA was used for analyses of the methylation patterns by bisulfite sequencing. Methylation status of the IGF2 and IGF2R genes were evaluated by sequencing 195 and 147 individual clones, respectively. No global differences in DNA methylation were found between NS, SX, and SY groups for the IGF2 (P = 0.09) or IGF2R genes (P = 0.38). Very specific methylation patterns were observed in the 25th and 26th CpG sites in the IGF2R gene. representing higher methylation in NS than in the SX and SY groups compared with the other CpG sites. Further, individual variation in methylation patterns was found among bulls. In conclusion, the sex‐sorting procedure by flow cytometry did not affect the overall DNA methylation patterns of the IGF2 and IGF2R genes, although individual variation in their methylation patterns among bulls was observed. Mol. Reprod. Dev. 79:77–84, 2012. © 2011 Wiley Periodicals, Inc.     

Arabidopsis and tobacco plants ectopically expressing the soybean antiquitin-like ALDH7 gene display enhanced tolerance to drought, salinity, and oxidative stress

Despite extensive studies in eukaryotic aldehyde dehydrogenases, functional information about the ALDH7 antiquitin-like proteins is lacking. A soybean antiquitin homologue gene, designated GmTP55, has been isolated which encodes a dehydrogenase motif-containing 55 kDa protein induced by dehydration and salt stress. GmTP55 is closely related to the stress-induced plant antiquitin-like proteins that belong to the ALDH7 family. Transgenic tobacco (Nicotiana tabacum) and Arabidopsis (Arabidopsis thaliana) plants constitutively expressing GmTP55 have been obtained in order to examine the physiological role of this enzyme under a variety of stress conditions. Ectopic expression of GmTP55 in both Arabidopsis and tobacco conferred tolerance to salinity during germination and to water deficit during plant growth. Under salt stress, the germination efficiency of both transgenic tobacco and Arabidopsis seeds was significantly higher than that of their control counterparts. Likewise, under progressive drought, the transgenic tobacco lines apparently kept the shoot turgidity to a normal level, which contrasted with the leaf wilt phenotype of control plants. The transgenic plants also exhibited an enhanced tolerance to H(2)O(2)- and paraquat-induced oxidative stress. Both GmTP55-expressing Arabidopsis and tobacco seeds germinated efficiently in medium supplemented with H(2)O(2), whereas the germination of control seeds was drastically impaired. Similarly, transgenic tobacco leaf discs treated with paraquat displayed a significant reduction in the necrotic lesions as compared with control leaves. These transgenic lines also exhibited a lower concentration of lipid peroxidation-derived reactive aldehydes under oxidative stress. These results suggest that antiquitin may be involved in adaptive responses mediated by a physiologically relevant detoxification pathway in plants.     

Expanded bed adsorption/desorption of proteins with Streamline Direct CST I adsorbent

Streamline Direct CST I is a new type of ion exchanger with multi-modal functional groups, specially designed for an expanded bed adsorption (EBA) process, which can capture directly the proteins from the high ionic strength feedstocks with a high binding capacity. In this study, an experimental study is carried out for two-component proteins (BSA and myoglobin) competitive adsorption and desorption in an expanded bed packed with Streamline Direct CST I. Based on the measurements of the single- and two-component bovine serum albumin (BSA)/myoglobin adsorption isotherm on Streamline Direct CST I, the binding and elution conditions for the whole EBA process are selected; and then frontal analysis for a longer timescale and column displacement experiments in a fixed bed (XK16/20 column) are carried out to evaluate the two-component proteins (BSA and myoglobin) competitive adsorption and displacement on Streamline Direct CST I. Finally, the feasibility of capturing both BSA and myoglobin by an expanded bed packed with Streamline Direct CST I is addressed in a Streamline 50 column packed with 300 mL Streamline Direct CST I.     

Characterization of an ecto-ATPase activity in Fonsecaea pedrosoi

In this work, we characterized an ecto-ATPase activity in intact mycelial forms of Fonsecaea pedrosoi, the primary causative agent of chromoblastomycosis. In the presence of 1 mM EDTA, fungal cells hydrolyzed adenosine-5′-triphosphate (ATP) at a rate of 84.6 ± 11.3 nmol Pi h⁻¹ mg⁻¹ mycelial dry weight. The ecto-ATPase activity was increased at about five times (498.3 ± 27.6 nmol Pi h⁻¹ mg⁻¹) in the presence of 5 mM MgCl₂, with values of V _max and apparent K _m for Mg-ATP²⁻corresponding to 541.9 ± 48.6 nmol Pi h⁻¹ mg⁻¹ cellular dry weight and 1.9 ± 0.2 mM, respectively. The Mg²⁺-stimulated ecto-ATPase activity was insensitive to inhibitors of intracellular ATPases such as vanadate (P-ATPases), bafilomycin A₁ (V-ATPases)_, and oligomycin (F-ATPases). Inhibitors of acid phosphatases (molybdate, vanadate, and fluoride) or alkaline phosphatases (levamizole) had no effect on the ecto-ATPase activity. The surface of the Mg²⁺-stimulated ATPase in F. pedrosoi was confirmed by assays in which 4,4′-diisothiocyanostylbene-2,2′-disulfonic acid (DIDS), a membrane impermeant inhibitor, and suramin, an inhibitor of ecto-ATPase and antagonist of P₂ purinoreceptors. Based on the differential expression of ecto-ATPases in the different morphological stages of F. pedrosoi, the putative role of this enzyme in fungal biology is discussed.     

Antimicrobial peptides from chilli pepper seeds causes yeast plasma membrane permeabilization and inhibits the acidification of the medium by yeast cells

During the last few years, a growing number of cysteine-rich antimicrobial peptides has been isolated from plants and particularly from seeds. It has become increasingly clear that these peptides play an important role in the protection of plants against microbial infection. In this work, proteins from chilli pepper (Capsicum annuum L.) seeds were extracted in phosphate buffer, pH 5.4 and peptides purification were performed by employing ion-exchange chromatographies on DEAE, CM-Sepharose, Sephacryl S-100 and reverse phase in HPLC. Three peptide enriched fractions, namely F1, F2 and F3, were obtained after the CM-Sepharose chromatography. The F1 fraction, mainly composed of three peptides ranging from 6 to 10 kDa, was submitted to N-terminal amino acid sequencing. The closer to 10 kDa peptide showed high sequence homology to lipid transfer proteins (LTPs) previously isolated from others seeds. F1 fraction exhibited strong fungicidal activity against Candida albicans, Saccharomyces cerevisiae and Schizosaccharomyces pombe and also promoted several morphological changes to C. albicans, including the formation of pseudohyphae, as revealed by scanning electron micrography. F1 fraction also reduced the glucose stimulated acidification of the medium mediated by H⁺-ATPase of S. cerevisiae cells in a dose-dependent manner and caused the permeabilization of yeast plasma membrane to the dye SYTOX Green, as verified by confocal laser microscopy.