Jaburetox, a natural insecticide derived from Jack Bean Urease, activates voltage-gated sodium channels to modulate insect behavior.

Jaburetox (Jbtx) is an insecticidal peptide derived from Canavalia ensiformis urease, whose mechanism of action is not completely elucidated. We employed behavioral, electromyographical and electrophysiological protocols to identify the cellular and molecular targets involved in the Jbtx entomotoxicity in cockroaches and locusts. In Nauphoeta cinerea, Jbtx (32 µg/g) altered the locomotory behaviour inducing a significative decrease in the distance travelled followed by a significant increase in stopped time (52 ±â€¯85 cm and 2573 ±â€¯89 s, p < .05, n = 40). Jbtx (8 to 32 µg/g body weight, respectively) also increased the leg and antennae grooming activities (p < .05, n = 40, respectively). Jbtx (8 to 16 µg/g) induced a maximum neuromuscular blockade of 80.72% (n = 6, p < .05) and was cardiotoxic, decreasing the cockroach heart rate. The electrophysiological profiles of both muscle and nerve of L. migratoria showed that Jbtx (2.5 × 10-7 and 2.5 × 10-3 µg/ body weight) induced a significant increase in the amplitude of nerve action potentials (n = 5, p < .05). Voltage clamp analysis of Jbtx (200 nM) applied in Xenopus laevis oocytes heterologously expressed with Nav 1.1 channels showed a significant increase in the sodium currents. In conclusion, this work revealed that the entomotoxic activity of Jbtx involves complex behavioral alterations that begins with an initial activation of voltage-gated sodium channels.

Phylogenetic positioning of the Antarctic alga Prasiola crispa (Trebouxiophyceae) using organellar genomes and their structural analysis.

Antarctica is one of the most difficult habitats for sustaining life on earth; organisms that live there have developed different strategies for survival. Among these organisms is the green alga Prasiola crispa, belonging to the class Trebouxiophyceae. The literature on P. crispa taxonomy is scarce, and many gaps in the evolutionary relationship with its closest relatives remain. The goal of this study was to analyze the evolutionary relationships between P. crispa and other green algae using plastid and mitochondrial genomes. In addition, we analyzed the synteny conservation of these genomes of P. crispa with those of closely related species. Based on the plastid genome, P. crispa grouped with Prasiolopsis sp. SAG 84.81, another Trebouxiophyceaen species from the Prasiola clade. Based on the mitochondrial genome analysis, P. crispa grouped with other Trebouxiophyceaen species but had a basal position. The structure of the P. crispa chloroplast genome had low synteny with Prasiolopsis sp. SAG 84.81, despite some conserved gene blocks. The same was observed in the mitochondrial genome compared with Coccomyxa subellipsoidea C-169. We were able to establish the phylogenetic position of P. crispa with other species of Trebouxiophyceae using its genomes. In addition, we described the plasticity of these genomes using a structural analysis. The plastid and mitochondrial genomes of P. crispa will be useful for further genetic studies, phylogenetic analysis and resource protection of P. crispa as well as for further phylogenetic analysis of Trebouxiophyceaen green algae.

HTT-DB: horizontally transferred transposable elements database.

MOTIVATION: Horizontal transfer of transposable (HTT) elements among eukaryotes was discovered in the mid-1980s. As then, >300 new cases have been described. New findings about HTT are revealing the evolutionary impact of this phenomenon on host genomes. In order to provide an up to date, interactive and expandable database for such events, we developed the HTT-DB database. RESULTS: HTT-DB allows easy access to most of HTT cases reported along with rich information about each case. Moreover, it allows the user to generate tables and graphs based on searches using Transposable elements and/or host species classification and export them in several formats. AVAILABILITY AND IMPLEMENTATION: This database is freely available on the web at http://lpa.saogabriel.unipampa.edu.br:8080/httdatabase. HTT-DB was developed based on Java and MySQL with all major browsers supported. Tools and software packages used are free for personal or non-profit projects. CONTACT: bdotto82@gmail.com or gabriel.wallau@gmail.com.

High throughput sequencing of the Angiostrongylus cantonensis genome: a parasite spreading worldwide.

Angiostrongylus cantonensis is a parasitic nematode of rodents and a leading aetiological agent of eosinophilic meningitis in humans. Definitive diagnosis is difficult, often relying on immunodiagnostic methods which utilize crude antigens. New immunodiagnostic methods based on recombinant proteins are being developed, and ideally these methods would be made available worldwide. Identification of diagnostic targets, as well as studies on the biology of the parasite, are limited by a lack of molecular information on Angiostrongylus spp. available in databases. In this study we present data collected from DNA random high-throughput sequencing together with proteomic analyses and a cDNA walking methodology to identify and obtain the nucleotide or amino acid sequences of unknown immunoreactive proteins. 28 080 putative ORFs were obtained, of which 3371 had homology to other deposited protein sequences. Using the A. cantonensis genomic sequences, 156 putative ORFs, matching peptide sequences obtained from previous proteomic studies, were considered novel, with no homology to existing sequences. Full-length coding sequences of eight antigenic target proteins were obtained. In this study we generated not only the complete nucleotide sequences of the antigenic protein targets but also a large amount of genomic data which may help facilitate future genomic, proteomic, transcriptomic or metabolomic studies on Angiostrongylus.

Venom characterization of the Brazilian Pampa snake Bothrops pubescens by top-down and bottom-up proteomics.

The envenomation from the Bothrops genus is characterized by systemic and local effects caused by the main toxin families in the venom. In Bothrops pubescens venom we were able to identify 89 protein groups belonging to 13 toxin families with the bottom-up proteomics approach and 40 unique proteoforms belonging to 6 toxin families with the top-down proteomics approach. We also identified multi-proteoform complexes of dimeric L-amino acid oxidase using native top-down mass spectrometry.

Are the Bacteria and Their Metabolites Contributing for Gut Inflammation on GSD-Ia Patients?

Recently, patients with glycogen storage disease (GSD) have been described as having gut dysbiosis, lower fecal pH, and an imbalance in SCFAs due to an increase in acetate and propionate levels. Here, we report the fecal measurement of bacterial-related metabolites formic, acetic, lactic, propionic, and succinic acid, a key metabolite of both host and microbiota, on a previously described cohort of 24 patients (GSD Ia = 15, GSD Ib = 5, 1 GSD III = 1 and GSD IX = 3) and 16 healthy controls, with similar sex and age, using the high-performance liquid chromatography technique. The succinic acid levels were higher in the GSD patients than in the controls (patients = 38.02; controls = 27.53; p = 0.045), without differences between the groups for other metabolites. Fecal pH present inverse correlation with lactic acid (R = -0.54; p = 0.0085), while OTUs were inversely correlated with both lactic (R = -0.46; p = 0.026) and formic (R = -0.54; p = 0.026) acids. Using two distinct metrics of diversity, borderline significance was obtained for propionic acid, affecting the microbial structure on Euclidean basis in 8% (r2 = 0.081; p = 0.079), and for lactic acid, affecting 6% of microbial structure using Bray-Curtis distance (r2 = 0.065; p = 0.060). No correlation was found between SCFAs and total carbohydrate consumption among the participants or uncooked cornstarch consumption among the patients.

Molecular characterization of ovine zygomycosis in central western Brazil.

Zygomycosis is an important granulomatous disease that affects humans and animals, particularly sheep in tropical regions. Rhinofacial and nasopharyngeal zygomycosis were described in sheep in association with Conidiobolus spp. The present study characterized 5 samples of Conidiobolus isolated from 3 herds with clinical disease in Mato Grosso State, Brazil. The clinical and pathological findings were similar to nasopharyngeal zygomycosis. Based on morphological features, isolates were classified as Conidiobolus spp., and molecular phylogenetic analyses based on 18S ribosomal DNA grouped all isolates in a Conidiobolus lamprauges cluster. The current report describes the molecular characterization of ovine nasopharyngeal zygomycosis associated with C. lamprauges.

HTT-DB: new features and updates.

Horizontal Transfer (HT) of genetic material between species is a common phenomenon among Bacteria and Archaea species and several databases are available for information retrieval and data mining. However, little attention has been given to this phenomenon among eukaryotic species mainly due to the lower proportion of these events. In the last years, a vertiginous amount of new HT events involving eukaryotic species was reported in the literature, highlighting the need of a common repository to keep the scientific community up to date and describe overall trends. Recently, we published the first HT database focused on HT of transposable elements among eukaryotes: the Horizontal Transposon Transfer DataBase (http://lpa.saogabriel.unipampa.edu.br: 8080/httdatabase/). Here, we present new features and updates of this unique database: (i) its expansion to include virus-host exchange of genetic material, which we called Horizontal Virus Transfer (HVT) and (ii) the availability of a web server for HT detection, where we implemented the online version of vertical and horizontal inheritance consistence analysis (VHICA), an R package developed for HT detection. These improvements will help researchers to navigate through known HVT cases, take data-informed decision and export figures based on keywords searches. Moreover, the availability of the VHICA as an online tool will make this software easily reachable even for researchers with no or little computation knowledge as well as foster our capability to detect new HT events in a wide variety of taxa. (Database URL: http://lpa.saogabriel.unipampa.edu.br:8080/httdatabase/).

Proteomic survey of the pathogenic Mycoplasma hyopneumoniae strain 7448 and identification of novel post-translationally modified and antigenic proteins.

Mycoplasma hyopneumoniae is an important pathogen for pigs, being the causative agent of enzootic pneumonia. Recently, the genome sequences of three strains, J, 7448 and 232 have been reported. Here, we describe the results of a proteomic analysis, based on two-dimensional gel electrophoresis of soluble protein extracts, immunoblot and mass spectrometry, which was carried out aiming the identification of gene products and antigenic proteins from the M. hyopneumoniae pathogenic strain 7448. A preliminary M. hyopneumoniae proteome map in two pH ranges (3-10 and 4-7) was produced. A total of 31 different coding DNA sequences (CDSs), including three hypothetical ones, were experimentally verified with the identification of the corresponding protein products by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. According to the Clusters of Orthologous Groups (COG) functional classification, the identified proteins were assigned to the groups of metabolism (13), cellular processes (5) and information and storage processing (4). Nine of the identified proteins were not classifiable by COG, including some related to cytoadherence and possibly involved in pathogenicity. Moreover, at least five highly antigenic proteins of M. hyopneumoniae were identified by immunoblots, including four novel ones (a heat shock protein 70, an elongation factor Tu, a pyruvate dehydrogenase E1-beta subunit and the P76 membrane protein). The now available proteome map is expected to serve as a reference for comparative analyses between M. hyopneumoniae pathogenic and non-pathogenic strains, and for methabolic studies based on cells cultured under modified conditions.

Bothriurus bonariensis scorpion venom activates voltage-dependent sodium channels in insect and mammalian nervous systems.

Animal venoms have been widely recognized as a major source of biologically active molecules. Bothriurus bonariensis, popularly known as black scorpion, is the arthropod responsible for the highest number of accidents involving scorpion sting in Southern Brazil. Here we reported the first attempt to investigate the neurobiology of B. bonariensis venom (BBV) in the insect and mammalian nervous system. BBV (32 µg/g) induced a slow neuromuscular blockade in the in vivo cockroach nerve-muscle preparations (70 ± 4%, n = 6, p < 0.001), provoking repetitive twitches and significantly decreasing the frequency of spontaneous leg action potentials (SNCAPs) from 82 ± 3 min(-1) to 36 ± 1.3 min(-1) (n = 6, p < 0.05), without affecting the amplitude. When tested in primary cultures of rat hippocampal cells, BBV induced a massive increase of Ca(2+) influx (250 ± 1% peak increase, n = 3, p < 0.0001). The disturbance of calcium homeostasis induced by BBV on the mammalian central nervous system was not accompanied by cellular death and was prevented by the co-treatment of the hippocampal cells with tetrodotoxin, a selective sodium channel blocker. The results suggest that the biological activity of BBV is mostly related to a modulation of sodium channels function. Our biological activity survey suggests that BBV may have a promising insecticidal and therapeutic potential.

Central and peripheral neurotoxicity induced by the Jack Bean Urease (JBU) in Nauphoeta cinerea cockroaches.

BACKGROUND: Ureases of Canavalia ensiformis are natural insecticides with a still elusive entomotoxic mode of action. We have investigated the mechanisms involved in the neurotoxicity induced by Jack Bean Urease (JBU) in Nauphoeta cinerea (Olivier). METHODS: To carry out this study we have employed biochemical and neurophysiological analysis of different cockroach organ systems. RESULTS AND CONCLUSIONS: The injection of the insects with JBU (0.75-6µg/g animal), although not lethal within 24h, caused significant inhibition of the brain acetylcholinesterase activity (60±5%, p<0.05, n=6). JBU (1.5µg/200µL), acetylcholine (0.3µg/200µL) or neostigmine (0.22µg/200µL), induced a positive cardiac chronotropism (∼25%) in the cockroaches (p<0.05, n=9). JBU (6µg/g) increased the insects' grooming activity (137±7%), similarly to octopamine (15µg/g) (p<0.05, n=30, respectively). Pretreating the insects with phentolamine (0.1µg/g) prevented the JBU- or octopamine-induced increase of grooming activity. JBU (6µg/g) caused 65±9% neuromuscular blockade in the cockroaches, an effect prevented by bicuculline (5µg/g) (p<0.05, n=6). JBU (6µg/g) decreased the frequency whilst increasing the amplitude of the spontaneous neural compound action potentials (1425±52.60min-1, controls 1.102±0.032mV, p<0.05, n=6, respectively). Altogether the results indicate that JBU induces behavioral alterations in Nauphoeta cinerea cockroaches probably by interfering with the cholinergic neurotransmission. The neuromuscular blocking activity of JBU suggests an interplay between acetylcholine and GABA signaling. GENERAL SIGNIFICANCE: The search for novel natural molecules with insecticide potential has become a necessity more than an alternative. Understanding the mode of action of candidate molecules is a crucial step towards the development of new bioinsecticides. The present study focused on the neurotoxicity of Canavalia ensiformis urease, a natural insecticide, in cockroaches and revealed interferences on the cholinergic, octopaminergic and GABA-ergic pathways as part of its entomotoxic mode of action.

Draft Plastid and Mitochondrial Genome Sequences from Antarctic Alga Prasiola crispa.

The organelle genomes of the Antarctic alga Prasiola crispa (Lightfoot) Kützing have been sequenced. The plastid and mitochondrial genomes have a total length of 196,502 bp and 89,819 bp, respectively. These genomes have 19 putative photosynthesis-related genes and 17 oxidative metabolism-related genes, respectively.

Proteomic analysis identifies differentially expressed proteins after red propolis treatment in Hep-2 cells.

Here we investigated alterations in the protein profile of Hep-2 treated with red propolis using two-dimensional electrophoresis associated to mass spectrometry and apoptotic rates of cells treated with and without red propolis extracts through TUNEL and Annexin-V assays. A total of 325 spots were manually excised from the two-dimensional gel electrophoresis and 177 proteins were identified using LC-MS-MS. Among all proteins identified that presented differential expression, most were down-regulated in presence of red propolis extract at a concentration of 120 µg/mL (IC50): GRP78, PRDX2, LDHB, VIM and TUBA1A. Only two up-regulated proteins were identified in this study in the non-cytotoxic (6 µg/mL) red propolis treated group: RPLP0 and RAD23B. TUNEL staining assay showed a markedly increase in the mid- to late-stage apoptosis of Hep-2 cells induced by red propolis at concentrations of 60 and 120 µg/mL when compared with non-treated cells. The increase of late apoptosis was confirmed by in situ Annexin-V analysis in which red propolis extract induced late apoptosis in a dose-dependent manner. The differences in tumor cell protein profiles warrant further investigations including isolation of major bioactive compounds of red propolis in different cell lines using proteomics and molecular tests to validate the protein expression here observed.

Evidence of alternative splicing of the chi2 chitinase gene from Metarhizium anisopliae.

Metarhizium anisopliae is a filamentous fungus used in the biological control of arthropods and produces several chitinases in order to break the host cuticle chitin fibers. Chitinase function during fungal cell development and/or infection processes is also an important aspect when analyzing the life cycle of entomopathogens. The expression profile analysis of the endochitinase chi2 gene acquired by RT-PCR experiments indicated the presence of two different transcripts, suggesting the occurrence of alternative splicing in the chi2 gene. The presence of two transcripts, characterized by the removal or retention of the second 72 bp intron, was further confirmed by DNA sequencing, Northern blot and qRT-PCR. Furthermore, we detected the synthesis of two different proteins from the transcripts by two-dimensional Western blot and mass spectrometry analyses. This is the first reported occurrence of alternative splicing in M. anisopliae.

The Metarhizium anisopliae trp1 gene: cloning and regulatory analysis.

The trp1 gene from the entomopathogenic fungus Metarhizium anisopliae, cloned by heterologous hybridization with the plasmid carrying the trpC gene from Aspergillus nidulans, was sequence characterized. The predicted translation product has the conserved catalytic domains of glutamine amidotransferase (G domain), indoleglycerolphosphate synthase (C domain), and phosphoribosyl anthranilate isomerase (F domain) organized as NH2-G-C-F-COOH. The ORF is interrupted by a single intron of 60 nt that is position conserved in relation to trp genes from Ascomycetes and length conserved in relation to Basidiomycetes species. RT-PCR analysis suggests constitutive expression of trp1 gene in M. anisopliae.

Molecular analysis of an integrative conjugative element, ICEH, present in the chromosome of different strains of Mycoplasma hyopneumoniae

Diversification of bacterial species and pathotypes is largely caused by lateral gene transfer (LGT) of diverse mobile DNA elements such as plasmids, phages, transposons and genomic islands. Thus, acquisition of new phenotypes by LGT is very important for bacterial evolution and relationship with hosts. This paper reports a 23 kb region containing fourteen CDSs with similarity to the previous described Integrative Conjugal Element of Mycoplasma fermentans (ICEF). This element, named ICEH, is present as one copy at distinct integration sites in the chromosome of 7448 and 232 pathogenic strains and is absent in the type strain J (non-pathogenic). Notable differences in the nucleotide composition of the insertion sites were detected, and could be correlated to a lack of specificity of the ICEH integrase. Although present in strains of the same organism, the ICEH elements are more divergent than the typical similarity between other chromosomal locus of Mycoplasma hyopneunomiae, suggesting an accelerated evolution of these constins or an ongoing process of degeneration, while maintaining conservation of the tra genes. An extrachromosomal form of this element had been detected in the 7448 strain, suggesting a possible involvement in its mobilization and transference of CDSs to new hosts.