Repertoire, Genealogy and Genomic Organization of Cruzipain and Homologous Genes in Trypanosoma cruzi, T. cruzi-Like and Other Trypanosome Species

Trypanosoma cruzi, the agent of Chagas disease, is a complex of genetically diverse isolates highly phylogenetically related to T. cruzi-like species, Trypanosoma cruzi marinkellei and Trypanosoma dionisii, all sharing morphology of blood and culture forms and development within cells. However, they differ in hosts, vectors and pathogenicity: T. cruzi is a human pathogen infective to virtually all mammals whilst the other two species are non-pathogenic and bat restricted. Previous studies suggest that variations in expression levels and genetic diversity of cruzipain, the major isoform of cathepsin L-like (CATL) enzymes of T. cruzi, correlate with levels of cellular invasion, differentiation, virulence and pathogenicity of distinct strains. In this study, we compared 80 sequences of genes encoding cruzipain from 25 T. cruzi isolates representative of all discrete typing units (DTUs TcI-TcVI) and the new genotype Tcbat and 10 sequences of homologous genes from other species. The catalytic domain repertoires diverged according to DTUs and trypanosome species. Relatively homogeneous sequences are found within and among isolates of the same DTU except TcV and TcVI, which displayed sequences unique or identical to those of TcII and TcIII, supporting their origin from the hybridization between these two DTUs. In network genealogies, sequences from T. cruzi clustered tightly together and closer to T. c. marinkellei than to T. dionisii and largely differed from homologues of T. rangeli and T. b. brucei. Here, analysis of isolates representative of the overall biological and genetic diversity of T. cruzi and closest T. cruzi-like species evidenced DTU- and species-specific polymorphisms corroborating phylogenetic relationships inferred with other genes. Comparison of both phylogenetically close and distant trypanosomes is valuable to understand host-parasite interactions, virulence and pathogenicity. Our findings corroborate cruzipain as valuable target for drugs, vaccine, diagnostic and genotyping approaches.

SOCIAL MONOGAMY AND BIPARENTAL CARE OF THE NEOTROPICAL SOUTHERN BAMBOO RAT (KANNABATEOMYS AMBLYONYX)

We analyzed social patterns indicative of the mating system and parental care in a population of the southern bamboo rat (Kannabateomys amblyonyx). This arboreal rodent feeds exclusively on bamboo stems and leaves. We conducted fieldwork from August 2003 to October 2004 in southern Brazil (30 degrees 20`-30 degrees 27`S, 50 degrees 50`-51 degrees 05`W), in patches of introduced Chinese bamboo (Bambusa tuldoides). We captured 18 individuals, 7 of which were adults that received radiotransmitters and were followed from 1 to 12 months. Another 5 animals (adults or subadults) received colored collars. We observed paternal care, delayed juvenile dispersal, and reduced degree of sexual dimorphism, all of which are traits typical of social monogamy. Mated males showed a direct parental behavioral repertoire similar to that of females (with the obvious exception of nursing), including grooming, huddling, and food provisioning. Potential monogamy in this species seems to be a flexible strategy linked to low density of bamboo patches. Females were confined to widely spaced., small home ranges, decreasing the possibility of male defense of and access to > 1 female. The arboreal habits of the species possibly increase the risk of inexperienced young falling from trees or else being depreciated when moving exposed through branches. This risk is probably reduced by the extensive biparental care observed, including the providing of low-energy plant food to young in the nest.

DivIVA-Mediated Polar Localization of ComN, a Posttranscriptional Regulator of Bacillus subtilis

ComN (YrzD) is a small, 98-amino-acid protein recently shown to be involved in the posttranscriptional control of the late competence comE operon in Bacillus subtilis. We show here that ComN localizes to the division site and cell poles in a DivIVA-dependent fashion. Yeast two-hybrid and glutathione S-transferase pulldown experiments showed that ComN interacts directly with DivIVA. ComN is not essential for the polar assembly of the core competence DNA uptake machinery. Nevertheless, polar localization of ComN should play some role in competence acquisition because delocalization of ComN leads to a small reduction in competence efficiency. We found that ComN promotes the accumulation of its target comE mRNA to septal and polar sites. Thus, we speculate that localized translation of ComE proteins may be required for efficient competence development. Our results underscore the versatility of DivIVA as a promoter of the differentiation of bacterial poles and demonstrate that the repertoire of polarly localized molecules in B. subtilis is broad, including a regulator of gene expression and its target mRNA. Moreover, our findings suggest that mRNA localization may play a role in the subcellular organization of bacteria.

Mating behaviour, nympho-imaginal development and description of a new Mesabolivar species (Araneae: Pholcidae) from the Brazilian dry forest

A new species of Mesabolivar is described from Brazilian forests: Mesabolivar delclaroi. The mating behaviour, postembryonic development, number of egg sacs and eggs, birth rate, number of instars, developmental time until adulthood, sex ratio and size of cephalothorax (per instar) were recorded. The sexual behaviour was described and categorized into four steps: courtship, pre-copulation, copulation and post-copulation. After hatching, individuals presented five instars until maturity. The mean number of eggs (42 +/- 16.6) and live births (31.5 +/- 3.4) of the first egg sac were significantly greater than that of a second one (23.8 +/- 3.8, and 19.25 +/- 3.9, respectively). The developmental time from birth to adulthood (130.8 +/- 9.6 days) did not differ significantly between egg sacs produced (128.61 +/- 11.1). The size of the cephalothorax did not differ among adults or between sexes. The sex ratio revealed a shift in favour of females (4: 3).

Using the Social Skills Inventory in the Diagnosis of Social Anxiety Disorder

This study aimed to assess the relationship between clinical and behavioral manifestations of the Social Anxiety Disorder (SAD) and verify the discriminative validity of the Social Skills Inventory (SSI-Del-Prette) in the diagnosis of this disorder. The participants were 1,006 undergraduates, aged between 17 and 35 years old, both genders. Subsequently, 86 participants were randomly selected from the initial sample and grouped as SAD cases and non-SAD cases through systematic clinical evaluation. The results indicated that the more elaborate the repertoire of social skills of an individual is, the lower his/her likelihood of meeting the screening criteria of diagnostic indicators for SAD. Furthermore, the SSI-Del-Prette has demonstrated to significantly distinguish individuals with and without SAD, evidencing, thus, its discriminative validity.

Preserving the B-Cell Compartment Favors Operational Tolerance in Human Renal Transplantation

Transplanted individuals in operational tolerance (OT) maintain long-term stable graft function after completely stopping immunosuppression. Understanding the mechanisms involved in OT can provide valuable information about pathways to human transplantation tolerance. Here we report that operationally tolerant individuals display quantitative and functional preservation of the B-c ell compartment in renal transplantation. OT exhibited normal numbers of circulating total B cells, naive, memory and regulatory B cells (Bregs) as well as preserved B-cell receptor repertoire, similar to healthy individuals. In addition, OT also displayed conserved capacity to activate the cluster of differentiation 40 (CD40)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in Bregs, in contrast, with chronic rejection. Rather than expansion or higher activation, we show that the preservation of the B-cell compartment favors OT. Online address: http://www.molmed.org doi: 10.2119/molmed.2011.00281

Combined snake venomics and venom gland transcriptomic analysis of Bothropoides pauloensis

Unraveling the repertoire of venom toxins of Bothropoides pauloensis was assessed by snake venomics and venom gland transcriptomic surveys. Both approaches yielded converging overall figures, pointing to metalloproteinases (similar to 37%), PLA(2)s (26-32%), and vasoactive (bradykinin-potentiating) peptides (12-17%) as the major toxin classes. The high occurrence of SVMPs, PLA(2) molecules, vasoactive peptides, along with serine proteinases, explains the local and systemic effects observed in envenomations by B. pauloensis. Minor (<3%) C-type lectin, serine proteinase, L-amino acid oxidase, nerve growth factor, and CRISP molecules were also identified in the transcriptome and the proteome. Low abundance (0.3%) EST singletons coding for vascular endothelial growth factor (svVEGF), ohanin, hyaluronidase, and 5' nucleotidase were found only in the venom gland cDNA library. At the molecular level, the transcriptomic and proteomic datasets display low compositional concordance. In particular, although there is good agreement between transcriptome and proteome in the identity of BPPs, PLA(2) molecules and L-amino acid oxidase, both datasets strongly depart in their C-type lectin and SVMP complements. These data support the view that venom composition is influenced by transcriptional and translational mechanisms and emphasize the value of combining proteomic and transcriptomic approaches to acquire a more complete understanding of the toxinological profile and natural history of the snake venom. (C) 2012 Elsevier B.V. All rights reserved.

Emoções de uma escuta musical afetam a percepção subjetiva de tempo

Este estudo verificou se emoções percebidas durante uma escuta musical influenciam a percepção temporal. Músicos e não músicos foram submetidos a tarefas de escuta de trechos musicais do repertório erudito ocidental com 20 segundos de duração cada um e tarefas de associação temporal de cada trecho ouvido a durações padrões, que variavam de 16 a 24 segundos. Os trechos musicais empregados eram representativos de uma dentre as categorias emocionais Alegria, Tristeza, Serenidade ou Medo / Raiva. Uma análise de variância mostrou que, enquanto os não músicos apresentaram subestimações temporais associadas a pelo menos um trecho musical de cada uma das categorias emocionais, os músicos subestimaram todos os trechos musicais tristes, relacionados às características de baixo arousal e valência afetiva negativa.

Stem cell therapy for type 1 diabetes mellitus: a review of recent clinical trials

Stem cell therapy is one of the most promising treatments for the near future. It is expected that this kind of therapy can ameliorate or even reverse some diseases. With regard to type 1 diabetes, studies analyzing the therapeutic effects of stem cells in humans began in 2003 in the Hospital das Clínicas of the Faculty of Medicine of Ribeirão Preto - SP USP, Brazil, and since then other centers in different countries started to randomize patients in their clinical trials. Herein we summarize recent data about beta cell regeneration, different ways of immune intervention and what is being employed in type 1 diabetic patients with regard to stem cell repertoire to promote regeneration and/or preservation of beta cell mass.

Distribution of nitrogen fixation and nitrogenase-like sequences amongst microbial genomes

Abstract Background The metabolic capacity for nitrogen fixation is known to be present in several prokaryotic species scattered across taxonomic groups. Experimental detection of nitrogen fixation in microbes requires species-specific conditions, making it difficult to obtain a comprehensive census of this trait. The recent and rapid increase in the availability of microbial genome sequences affords novel opportunities to re-examine the occurrence and distribution of nitrogen fixation genes. The current practice for computational prediction of nitrogen fixation is to use the presence of the nifH and/or nifD genes. Results Based on a careful comparison of the repertoire of nitrogen fixation genes in known diazotroph species we propose a new criterion for computational prediction of nitrogen fixation: the presence of a minimum set of six genes coding for structural and biosynthetic components, namely NifHDK and NifENB. Using this criterion, we conducted a comprehensive search in fully sequenced genomes and identified 149 diazotrophic species, including 82 known diazotrophs and 67 species not known to fix nitrogen. The taxonomic distribution of nitrogen fixation in Archaea was limited to the Euryarchaeota phylum; within the Bacteria domain we predict that nitrogen fixation occurs in 13 different phyla. Of these, seven phyla had not hitherto been known to contain species capable of nitrogen fixation. Our analyses also identified protein sequences that are similar to nitrogenase in organisms that do not meet the minimum-gene-set criteria. The existence of nitrogenase-like proteins lacking conserved co-factor ligands in both diazotrophs and non-diazotrophs suggests their potential for performing other, as yet unidentified, metabolic functions. Conclusions Our predictions expand the known phylogenetic diversity of nitrogen fixation, and suggest that this trait may be much more common in nature than it is currently thought. The diverse phylogenetic distribution of nitrogenase-like proteins indicates potential new roles for anciently duplicated and divergent members of this group of enzymes.

Identification of SL addition trans-splicing acceptor sites in the internal transcribed spacer I region of pre-rRNA in Leishmania (Leishmania) amazonensis

Trypanosomatidae is a family of early branching eukaryotes harbouring a distinctive repertoire of gene expression strategies. Functional mature messenger RNA is generated via the trans-splicing and polyadenylation processing of constitutively transcribed polycistronic units. Recently, trans-splicing of pre-small subunit ribosomal RNA in the 5' external transcribed spacer region and of precursor tRNAsec have been described. Here, we used a previously validated semi-nested reverse transcription-polymerase chain reaction strategy to investigate internal transcribed spacer (ITS) I acceptor sites in total RNA from Leishmania (Leishmania) amazonensis. Two distinct spliced leader-containing RNAs were detected indicating that trans-splicing reactions occur at two AG acceptor sites mapped in this ITS region. These data provide further evidence of the wide spectrum of RNA molecules that act as trans-splicing acceptors in trypanosomatids.

A teatralização da política: a propaganda abolicionista

Este artigo argumenta que, ao buscar modelos no repertório abolicionista estrangeiro para construir sua propaganda, os abolicionistas brasileiros viram suas possibilidades de escolha restritas pelas oportunidades políticas locais e pela tradição local católica. Contingências que impediram a simples transposição do modelo de ativismo estrangeiro e conduziram a uma atividade criativa de apropriação, em diálogo com o contexto e a tradição brasileiros. Processo que resultou numa reinvenção, uma vez que as artes, sobretudo o teatro, ganharam na propaganda abolicionista brasileira a proeminência que a religião teve na anglo-americana.

Genome sequence of Xanthomonas fuscans subsp. fuscans strain 4834-R reveals that flagellar motility is not a general feature of xanthomonads

Abstract Background Xanthomonads are plant-associated bacteria responsible for diseases on economically important crops. Xanthomonas fuscans subsp. fuscans (Xff) is one of the causal agents of common bacterial blight of bean. In this study, the complete genome sequence of strain Xff 4834-R was determined and compared to other Xanthomonas genome sequences. Results Comparative genomics analyses revealed core characteristics shared between Xff 4834-R and other xanthomonads including chemotaxis elements, two-component systems, TonB-dependent transporters, secretion systems (from T1SS to T6SS) and multiple effectors. For instance a repertoire of 29 Type 3 Effectors (T3Es) with two Transcription Activator-Like Effectors was predicted. Mobile elements were associated with major modifications in the genome structure and gene content in comparison to other Xanthomonas genomes. Notably, a deletion of 33 kbp affects flagellum biosynthesis in Xff 4834-R. The presence of a complete flagellar cluster was assessed in a collection of more than 300 strains representing different species and pathovars of Xanthomonas. Five percent of the tested strains presented a deletion in the flagellar cluster and were non-motile. Moreover, half of the Xff strains isolated from the same epidemic than 4834-R was non-motile and this ratio was conserved in the strains colonizing the next bean seed generations. Conclusions This work describes the first genome of a Xanthomonas strain pathogenic on bean and reports the existence of non-motile xanthomonads belonging to different species and pathovars. Isolation of such Xff variants from a natural epidemic may suggest that flagellar motility is not a key function for in planta fitness.