The evolution of behavioural systems: a study of grooming in rodents

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparative Chromosome Mapping of U2 snRNA and 5S rRNA Genes in Gymnotus Species (Gymnotiformes, Gymnotidae): Evolutionary Dynamics and Sex Chromosome Linkage in G. pantanal

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Modelagem matemática de tumores e estequiometria biológica

Cancer biology is a complex and expanding field of science study. Due its complexity, there is a strong motivation to integrate many fields of knowledge to study cancer biology, and biological stoichiometry can make this. Biological stoichiometry is the study of the balance of multiple chemical elements in biological systems. A key idea in biological stoichiometry is the growth rate hypothesis, which states that variation in the carbon:nitrogen:phosphorus stoichiometry of living things is associated with growth rate because of the elevated demands for phosphorusrich ribosomal RNA and other elements necessary to protein synthesis. As tumor cells has high rate proliferation, the growth rate hypothesis can be used in cancer study. In this work the dynamic of two tumors (primary and secondary) and the chemical elements carbon and nitrogen are simulate and analyzed through mathematical models that utilize as central idea biological stoichiometry. Differential equations from mathematical model are solved by numerical method Runge-Kutta fourth order

ITScan: a web-based analysis tool for Internal Transcribed Spacer (ITS) sequences

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

First detection of Leishmania spp. DNA in Brazilian bats captured strictly in urban areas

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

First genetic identification of Cryptosporidium parvum subtype IIaA14G2R1in beef cattle in Brazil

The presence of Cryptosporidium spp. in a cattle herd registered with an outbreak of diarrhea was investigated and the the molecular subtyping of Cryptosporidium parvum was characterized. Fecal samples from 85 Nellore beef cattle (Bos indicus) were collected and examined with Ziehl-Neelsen modified staining method. Fifty-four cattle (63.52%) had Cryptosporidium spp. oocysts in their feces. Fragments of genes encoding the 18S ribosomal RNA subunit and a 60-kDa glycoprotein (gp60) were amplified by nested PCR accomplished in the 11 most heavily parasitized samples, and the amplicons were sequenced. Eight of the 11 analyzed samples were positive for 18S rRNA sequences and identified monospecific infections with C. parvum. Seven samples were positive for gp60 and identified subtypes IIaA15G2R1 (6/11) and IIaA14G2R1 (1/11). This report is the first for C. parvum subtype IIaA14G2R1 in beef cattle in Brazil.

Francisella noatunensis orientalis em tilápias (Oreochromis niloticus) cultivadas em tanques-rede na bacia hidrográfica do rio Araguari-Minas Gerais

Pós-graduação em Medicina Veterinária - FMVZ 33004064022P3

Francisella noatunensis orientalis em tilápias (Oreochromis niloticus) cultivadas em tanques-rede na bacia hidrográfica do rio Araguari-Minas Gerais

Pós-graduação em Medicina Veterinária - FMVZ

Revealing archaeal diversity patterns and methane fluxes in Admiralty Bay, King George Island, and their association to Brazilian Antarctic Station activities

The study of Antarctic archaeal communities adds information on the biogeography of this group and helps understanding the dynamics of biogenic methane production in such extreme habitats. Molecular methods were combined to methane flux determinations in Martel Inlet, Admiralty Bay, to assess archaeal diversity, to obtain information about contribution of the area to atmospheric methane budget and to detect possible interferences of the Antarctic Brazilian Station Comandante Ferraz (EACF) wastewater discharge on local archaeal communities and methane emissions. Methane fluxes in Martel Inlet ranged from 3.2 to 117.9 mu mol CH(4) m(-2) d(-1), with an average of 51.3 +/- 8.5 mu mol CH(4) m(-2) d(-1) and a median of 57.6 mu mol CH(4) m(-2)d(-1). However, three negative fluxes averaging -11.3 mu mol CH(4) m(-2) d(-1) were detected in MacKellar Inlet, indicating that Admiralty Bay can be either a source or sink of atmospheric methane. Denaturing gradient gel electrophoresis (DGGE) showed that archaeal communities at EACF varied with depth and formed a group separated from the reference sites. Granulometric analysis indicated that differences observed may be mostly related to sediment type. However, an influence of wastewater input could not be discarded, since higher methane fluxes were found at CF site. suggesting stimulation of local methanogenesis. DGGE profile of the wastewater sample grouped separated from all other samples, suggesting that methanogenesis stimulation may be due to changes in environmental conditions rather than to the input of allochtonous species from the wastewater. 16S ribosomal DNA clone libraries analysis showed that all wastewater sequences were related to known methanogenic groups belonging to the hydrogenotrophic genera Methanobacterium and Methanobrevibacter and the aceticlastic genus Methanosaeta. EACF and Botany Point sediment clone libraries retrieved only groups of uncultivated Archaea, with predominance of Crenarchaeota representatives (MCG, MG1, MBG-B, MBG-C and MHVG groups). Euryarchaeota sequences found were mostly related to the LDS and RC-V groups, but MBG-D and DHVE-5 were also present. No representatives of cultivated methanogenic groups were found, but coverage estimates suggest that a higher number of clones would have to be analyzed in order to cover the greater archaeal diversity of Martel Inlet sediment. Nevertheless, the analysis of the libraries revealed groups not commonly found by other authors in Antarctic habitats and also indicated the presence of groups of uncultivated archaea previously associated to methane rich environments or to the methane cycle. (C) 2010 Elsevier Ltd. All rights reserved.

Amazonian Anthrosols Support Similar Microbial Communities that Differ Distinctly from Those Extant in Adjacent, Unmodified Soils of the Same Mineralogy

We compared the microbial community composition in soils from the Brazilian Amazon with two contrasting histories; anthrosols and their adjacent non-anthrosol soils of the same mineralogy. The anthrosols, also known as the Amazonian Dark Earths or terra preta, were managed by the indigenous pre-Colombian Indians between 500 and 8,700 years before present and are characterized by unusually high cation exchange capacity, phosphorus (P), and calcium (Ca) contents, and soil carbon pools that contain a high proportion of incompletely combusted biomass as biochar or black carbon (BC). We sampled paired anthrosol and unmodified soils from four locations in the Manaus, Brazil, region that differed in their current land use and soil type. Community DNA was extracted from sampled soils and characterized by use of denaturing gradient gel electrophoresis (DGGE) and terminal restriction fragment length polymorphism. DNA bands of interest from Bacteria and Archaea DGGE gels were cloned and sequenced. In cluster analyses of the DNA fingerprints, microbial communities from the anthrosols grouped together regardless of current land use or soil type and were distinct from those in their respective, paired adjacent soils. For the Archaea, the anthrosol communities diverged from the adjacent soils by over 90%. A greater overall richness was observed for Bacteria sequences as compared with those of the Archaea. Most of the sequences obtained were novel and matched those in databases at less than 98% similarity. Several sequences obtained only from the anthrosols grouped at 93% similarity with the Verrucomicrobia, a genus commonly found in rice paddies in the tropics. Sequences closely related to Proteobacteria and Cyanobacteria sp. were recovered only from adjacent soil samples. Sequences related to Pseudomonas, Acidobacteria, and Flexibacter sp. were recovered from both anthrosols and adjacent soils. The strong similarities among the microbial communities present in the anthrosols for both the Bacteria and Archaea suggests that the microbial community composition in these soils is controlled more strongly by their historical soil management than by soil type or current land use. The anthrosols had consistently higher concentrations of incompletely combusted organic black carbon material (BC), higher soil pH, and higher concentrations of P and Ca compared to their respective adjacent soils. Such characteristics may help to explain the longevity and distinctiveness of the anthrosols in the Amazonian landscape and guide us in recreating soils with sustained high fertility in otherwise nutrient-poor soils in modern times.

Gastrotricha: A Marine Sister for a Freshwater Puzzle

Background: Within an evolutionary framework of Gastrotricha Marinellina flagellata and Redudasys fornerise bear special interest, as they are the only Macrodasyida that inhabit freshwater ecosystems. Notwithstanding, these rare animals are poorly known; found only once (Austria and Brazil), they are currently systematised as incertae sedis. Here we report on the rediscovery of Redudasys fornerise, provide an account on morphological novelties and present a hypothesis on its phylogenetic relationship based on molecular data. Methodology/Principal Findings: Specimens were surveyed using DIC microscopy and SEM, and used to obtain the 18 S rRNA gene sequence; molecular data was analyzed cladistically in conjunction with data from 42 additional species belonging to the near complete Macrodasyida taxonomic spectrum. Morphological analysis, while providing new information on taxonomically relevant traits (adhesive tubes, protonephridia and sensorial bristles), failed to detect elements of the male system, thus stressing the parthenogenetic nature of the Brazilian species. Phylogenetic analysis, carried out with ML, MP and Bayesian approaches, yielded topologies with strong nodal support and highly congruent with each other. Among the supported groups is the previously undocumented clade showing the alliance between Redudasys fornerise and Dactylopodola agadasys; other strongly sustained clades include the densely sampled families Thaumastodermatidae and Turbanellidae and most genera. Conclusions/Significance: A reconsideration of the morphological traits of Dactylopodola agadasys in light of the new information on Redudasys fornerise makes the alliance between these two taxa very likely. As a result, we create Anandrodasys gen. nov. to contain members of the previously described D. agadasys and erect Redudasyidae fam. nov. to reflect this novel relationship between Anandrodasys and Redudasys. From an ecological perspective, the derived position of Redudasys, which is deeply nested within the Macrodasyida clade, unequivocally demonstrates that invasion of freshwater by gastrotrichs has taken place at least twice, in contrast with the single event hypothesis recently put forward.

Levels of Selenomonas species in generalized aggressive periodontitis

Goncalves LFH, Fermiano D, Feres M, Figueiredo LC, Teles FRP, Mayer MPA, Faveri M. Levels of Selenomonas species in generalized aggressive periodontitis. J Periodont Res 2012; 47: 711718. (c) 2012 John Wiley & Sons A/S Background and Objective: To compare the levels of Selenomonas sputigena and uncultivated/unrecognized Selenomonas species in subgingival biofilms from periodontally healthy subjects and from subjects with generalized aggressive periodontitis. Material and Methods: Fifteen periodontally healthy subjects and 15 subjects with generalized aggressive periodontitis were recruited and their clinical periodontal parameters were evaluated. Nine subgingival plaque samples were collected from each subject and all were individually analyzed for the levels of 10 bacterial taxa, including cultured and uncultivated/unrecognized microorganisms, using the RNA-oligonucleotide quantification technique. Between-group differences in the levels of the test taxa were determined using the MannWhitney U-test. Results: Subjects with generalized aggressive periodontitis showed significantly higher mean counts of Porphyromonas gingivalis, S. sputigena and the Mitsuokella sp. Human Oral Taxon (HOT) 131 (previously described as Selenomonas sp. oral clone CS002), while higher mean counts of Actinomyces gerencseriae and Streptococcus sanguinis were found in periodontally healthy subjects (p < 0.01). Selenomonas sp. HOT 146 was only detected in the generalized aggressive periodontitis group. In the generalized aggressive periodontitis group, the levels of P.gingivalis and S.sputigena were higher in deep sites (probing depth = 5 mm) than in shallow sites (probing depth = 3 mm) (p < 0.01). Furthermore, in subjects with generalized aggressive periodontitis, sites with probing depth of = 3 mm harbored higher levels of these two species than sites with the same probing depth in periodontally healthy subjects. There were positive correlations between probing depth and the levels of P.gingivalis (r = 0.77; p < 0.01), S.sputigena (r = 0.60; p < 0.01) and Selenomonas dianae (previously described as Selenomonas sp. oral clone EW076) (r = 0.42, p < 0.05). Conclusion: S. sputigena and Mitsuokella sp. HOT 131 may be associated with the pathogenesis of generalized aggressive periodontitis, and their role in the onset and progression of this infection should be investigated further.

Karyotype characterization reveals an up and down of 45S and 5S rDNA sites in Crotalaria (Leguminosae-Papilionoideae) species of the section Hedriocarpae subsection Macrostachyae

The genus Crotalaria is one of the largest within the family Leguminosae-Papilionoideae, with more than 600 species. However, few karyotypes have been described. In the present paper, five species belonging to the section Hedriocarpae were studied (subsection Machrostachyae), in order to better understand chromosomal evolution in Crotalaria. The results reveals that all species presented 2n = 2x = 16 with symmetrical karyotypes, and slight differences in the chromosome morphology. A secondary constriction was identified at short arm of the pair 1. The 45S rDNA was mapped in the secondary constriction and adjacent heterochromatin (NOR-heterochromatin) and a minor site was identified in C. ochroleuca. The 5S rDNA was mapped linked to 45S rDNA at chromosome 1 short arm in all species. Additional sites for 5S rDNA were identified in C. pallida, C. striata and C. mucronata. Heterochromatin blocks around the centromeres are not CMA(+) neither DAPI(+). The karyotypes of the subsection Macrostachyae are characterized by an inversion at chromosome pair one in relation to previous specialized floral species analyzed. Additional sites of 45S and 5S rDNA were assumed to be a result of transposition events by different ways. The results suggest heterochromatin differentiation and the position of ribosomal genes indicates chromosomal rearrangements during evolution. Karyotype characteristics corroborate the morphological infrageneric classification.

Mechanical loading induces the expression of a Pol I regulon at the onset of skeletal muscle hypertrophy

von Walden F, Casagrande V, Ostlund Farrants AK, Nader GA. Mechanical loading induces the expression of a Pol I regulon at the onset of skeletal muscle hypertrophy. Am J Physiol Cell Physiol 302: C1523-C1530, 2012. First published March 7, 2012; doi:10.1152/ajpcell.00460.2011.-The main goal of the present study was to investigate the regulation of ribosomal DNA (rDNA) gene transcription at the onset of skeletal muscle hypertrophy. Mice were subjected to functional overload of the plantaris by bilateral removal of the synergist muscles. Mechanical loading resulted in muscle hypertrophy with an increase in rRNA content. rDNA transcription, as determined by 45S pre-rRNA abundance, paralleled the increase in rRNA content and was consistent with the onset of the hypertrophic response. Increased transcription and protein expression of c-Myc and its downstream polymerase I (Pol I) regulon (POL1RB, TIF-1A, PAF53, TTF1, TAF1C) was also consistent with the increase in rRNA. Similarly, factors involved in rDNA transcription, such as the upstream binding factor and the Williams syndrome transcription factor, were induced by mechanical loading in a corresponding temporal fashion. Chromatin immunoprecipitation revealed that these factors, together with Pol I, were enriched at the rDNA promoter. This, in addition to an increase in histone H3 lysine 9 acetylation, demonstrates that mechanical loading regulates rRNA synthesis by inducing a gene expression program consisting of a Pol I regulon, together with accessory factors involved in transcription and chromatin remodeling at the rDNA promoter. Altogether, these data indicate that transcriptional and epigenetic mechanisms take place in the regulation of ribosome production at the onset of muscle hypertrophy.

Cwc24p Is a General Saccharomyces cerevisiae Splicing Factor Required for the Stable U2 snRNP Binding to Primary Transcripts

Splicing of primary transcripts is an essential process for the control of gene expression. Specific conserved sequences in premature transcripts are important to recruit the spliceosome machinery. The Saccharomyces cerevisiae catalytic spliceosome is composed of about 60 proteins and 5 snRNAs (U1, U2, U4/U6 and U5). Among these proteins, there are core components and regulatory factors, which might stabilize or facilitate splicing of specific substrates. Assembly of a catalytic complex depends on the dynamics of interactions between these proteins and RNAs. Cwc24p is an essential S. cerevisiae protein, originally identified as a component of the NTC complex, and later shown to affect splicing in vivo. In this work, we show that Cwc24p also affects splicing in vitro. We show that Cwc24p is important for the U2 snRNP binding to primary transcripts, co-migrates with spliceosomes, and that it interacts with Brr2p. Additionally, we show that Cwc24p is important for the stable binding of Prp19p to the spliceosome. We propose a model in which Cwc24p is required for stabilizing the U2 association with primary transcripts, and therefore, especially important for splicing of RNAs containing non- consensus branchpoint sequences.