A new member of the ribbon-helix-helix transcription factor superfamily from the plant pathogen Xanthomonas axonopodis pv. citri

XACb0070 is an uncharacterized protein coded by the two large plasmids isolated from Xanthomonas axonopodis pv. cirri, the agent of citrus canker and responsible for important economical losses in citrus world production. XACb0070 presents sequence homology only with other hypothetical proteins belonging to plant pathogens, none of which have their structure determined. The NMR-derived solution structure reveals this protein is a homodimer in which each monomer presents two domains with different structural and dynamic properties: a folded N-terminal domain with beta alpha alpha topology which mediates dimerization and a long disordered C-terminal tail. The folded domain shows high structural similarity to the ribbon-helix-helix transcriptional repressors, a family of DNA-binding proteins of conserved 3D fold but low sequence homology: indeed XACb0070 binds DNA. Primary sequence and fold comparison of XACb0070 with other proteins of the ribbon-helix-helix family together with examination of the genes in the vicinity of xacb0070 suggest the protein might be the component of a toxin-antitoxin system. (C) 2010 Elsevier Inc. All rights reserved.

Implementing stepwise solvent elution in sequential injection chromatography for fluorimetric determination of intracellular free amino acids in the microalgae Tetraselmis gracilis

The concept of sequential injection chromatography (SIC) was exploited to automate the fluorimetric determination of amino acids after pre-column derivatization with ophthaldialdehyde (OPA) in presence of 2-mercaptoethanol (2MCE) using a reverse phase monolithic C(18) stationary phase. The method is low-priced and based on five steps of isocratic elutions. The first step employs the mixture methanol: tetrahydrofuran: 10 mmol L(-1) phosphate buffer (pH 7.2) at the volumetric ratio of 8:1:91; the other steps use methanol: 10 mmol L-1 phosphate buffer (pH 7.2) at volumetric ratios of 20:80, 35:65, SO:SO and 65:35. At a flow rate of 10 mu L s(-1) a 25 mm long-column was able to separate aspartic acid (Asp), glutamic acid (Glu), asparagine (Asn), serine (Ser), glutamine (Gln), glycine (Gly), threonine (Thr), citruline (Ctr), arginine (Arg), alanine (Ala), tyrosine (Tyr), phenylalanine (Phe), ornithine (Orn) and lysine (Lys) with resolution >1.2 as well as methionine (Met) and valine (Val) with resolution of 0.6. Under these conditions isoleucine (Ile) and leucine (Leu) co-eluted. The entire cycle of amino acids derivatization, chromatographic separation and column conditioning at the end of separation lasted 25 min. At a flow rate of 40 mu L s(-1) such time was reduced to 10 min at the cost of resolution worsening for the pairs Ctr/Arg and Orn/Lys. The detection limits varied from 0.092 mu mol L(-1) for Tyr to 0.51 mu mol L(-1) for Orn. The method was successfully applied to the determination of intracellular free amino acids in the green alga Tetraselmis gracilis during a period of seven days of cultivation. Samples spiked with known amounts of amino acids resulted in recoveries between 94 and 112%. (C) 2008 Elsevier B.V. All rights reserved.

Genetic Diversity of a Brazilian Strain Collection of Xanthomonas citri subsp citri Based on the Type III Effector Protein Genes

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

Genes diferencialmente expressos em cana-de-açúcar inoculada com Xanthomonas albilineans, o agente causal da escaldadura da folha

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

First polymorphisms in JY-1 gene in cattle (Bos taurus indicus) and their association with sexual precocity and growth traits

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

Formulação de rações para poedeiras com base em aminoácidos totais e digestíveis utilizando diferentes estimativas da composição de aminoácidos em alimentos

Foram utilizadas poedeiras comerciais com 27 semanas de idade, distribuídas em delineamento inteiramente ao acaso, em esquema fatorial 3 x 3, com três repetições de seis aves por tratamento. Os fatores consistiram de três métodos de estimativa da composição de aminoácidos em ingredientes (tabelas brasileiras, equações de predição e fator para correção de aminoácido em função do teor de proteína do ingrediente) e três recomendações de aminoácidos, sendo duas de aminoácidos digestíveis e uma de aminoácidos totais. Os métodos de estimativa da composição de aminoácidos nos ingredientes afetaram apenas a conversão alimentar e a espessura de casca, que apresentaram os melhores resultados com a utilização das tabelas brasileiras. Embora as recomendações de aminoácidos tenham determinado diferenças em todos os parâmetros de desempenho, não afetaram a qualidade dos ovos. O desempenho das aves foi prejudicado pelos níveis de aminoácidos digestíveis, entretanto, ambas as recomendações promoveram desempenho semelhante e inferior ao de aminoácidos totais. O pior desempenho das aves alimentadas com as rações formuladas com aminoácidos digestíveis pode ser atribuído à deficiência em nitrogênio para a síntese de aminoácidos não-essenciais, visto que o nível protéico foi reduzido (12,5% PB), ou ainda à deficiência nos aminoácidos arginina, histidina, isoleucina, leucina e valina, cujos requerimentos mínimos não foram considerados na formulação das rações.

Digestibilidade do extrato de leveduras em frangos de corte

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

Functional alterations in endocrine pancreas of rats with different degrees of dexamethasone-induced insulin resistance

Objectives: We have analyzed the peripheral insulin and glucose sensitivity in vivo, and islet function ex vivo in rats with different degrees of insulin resistance induced by dexamethasone (DEX).Methods: Dexamethasone, in the concentrations of 0.1 (DEX 0.1), 0.5 (DEX 0.5), and 1.0 mg/kg body weight (DEX 1.0) was administered daily, intraperitoneally, to adult Wistar rats for 5 days, whereas controls received saline.Results: Dexamethasone treatment induced peripheral insulin resistance in a dose-dependent manner. At the end of the treatment, only DEX 1.0 rats showed significant increase of postabsorptive blood glucose and serum triglycerides, and nonesterified fatty acids levels. Incubation of pancreatic islets in increasing glucose concentrations (2.8-22 mM) led to an augmented insulin secretion in all DEX-treated rats. Leucine, carbachol, and high KCl concentrations induced the insulin release in DEX 0.5 and DEX 1.0, whereas arginine augmented secretion in all DEX-treated groups.Conclusions: We demonstrate that in DEX 0.5 and, especially in DEX 0.1 groups, but not in DEX 1.0, the adaptations that occurred in the endocrine pancreas are able to counteract metabolic disorders (glucose intolerance and dyslipidemia). These animal models seem to be interesting approaches for the study of degrees of subjacent effects that may mediate type 2 diabetes (DEX 1.0) and islet function alterations, without collateral effects (DEX 0.1 and DEX 0.5).

Digestibilidade aparente do triticale para a tilápia-do-nilo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Growth hormone 1 gene (GH1) polymorphisms as possible markers of the production potential of beef cattle using the Brazilian Canchim breed as a model

The growth hormone 1 gene (GH1) is a candidate gene for body weight and weight gain in cattle since it plays a fundamental role in growth regulation. We investigated the GH1 gene AluI and DdeI restriction enzyme polymorphisms, located 149 bp apart in the cattle genome, as possible markers of the production potential of Canchim crossbreed cattle, a 5/8 Charolais (Bos taurus) and 3/8 Nelore (Bos indicus) breed developed in Brazil, by evaluating the birth weight, weaning weight, yearling weight and plasma insulin-like growth factor-1 (IGF-1) concentration of 7 month to 10 months old Canchim calves (n = 204) of known genealogy and which had been genotyped for the AluI and DdeI markers. Our results showed significant effect (p < 0.05) between the homozygous DdeI+/DdeI+ polymorphism and the estimated breeding value for weaning weight (ESB-WW), while the AluI leucine homozygous (L/L) and leucine/valine (L/V) heterozygous polymorphisms showed no significant effect on the traits studied. The restriction sites of the two enzymes led to the formation of haplotypes which also exerted a significant effect (p < 0.05) on the ESB-WW, with the largest difference being 8.5 kg in favor of the homozygous L plus DdeI+/L plus DdeI+ genotype over the heterozygous L plus DdeI-/V plus DdeI+ genotype.

Characterization of a Local Renin-Angiotensin System in Rat Gingival Tissue

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

Isoenzimatic variability among five peanut cultivars

A variabilidade genética foi avaliada dentro e entre amostras de diferentes cultivares de amendoim, Arachis hypogaea L., conhecidos como Roxo, Tatu Branco, Tatu Vermelho, Tatuí Vermelho e Tatuí (sementes com película branca), fornecidos por fazendas situadas nas regiões dos municípios de Marília, Presidente Prudente e São Manuel. Para tal análise, foi utilizada a técnica de eletroforese horizontal em gel de poliacrilamida, para os sistemas da leucil-aminopeptidase (LAP), aspartato aminotransferase (ATT) e peroxidase (PER). No sistema da leucil-aminopeptidase, foram observadas três bandas enzimáticas, denominadas LAP-A, LAP-B e LAP-C. Os padrões de bandas obtidos para o sistema da aspartato-aminotransferase mostraram a existência de três bandas anódicas, AAT-A, AAT-B e AAT-C. No sistema da peroxidase (PER), foram observadas quinze bandas, sendo oito anódicas (PER-A a PER-H) e sete catódicas (PER-I a PER-P). Os sistemas enzimáticos da peroxidase e leucil-aminopeptidase não foram discriminativos para as amostras analisadas dos diferentes cultivares obtidos nas diversas regiões. O sistema da aspartato-aminotransferase apresentou um padrão composto pelas bandas AAT-B e AAT-C, que se mostrou característico e discriminativo para as amostras do cultivar Tatu Branco, procedente de Presidente Prudente, e do 'Tatuí Vermelho', proveniente de Presidente Prudente e São Manuel.

Keratinolytic activity of Streptomyces sp isolated of poultry processing plant

The keratin is not degraded by common enzyme, keratinases have the ability to degrade native keratin and others insoluble enzymes. In the present work was Studied keratinase produced by Streptomyces sp LMI-1 isolated from industrial plant of poultry processing. The enzyme degraded 87% of feathers after 120 h, it was stimulated by Ba(2+) and inhibited by Ca(2+), Mn(2+), EDTA and Hg(+). The optimum pH and temperature for the enzyme was 8.5 and 60 degrees C, respectively. The enzyme was stable after 2 hours at 50 degrees C. The culture broth analysis by thin layer chromatography showed presence of amino acids serine, methionine, proline, tyrosine and leucine after 72 hours of incubation. The microorganism showed potential for use in industrial process because of higher enzyme production and feathers degradation.

Phylogeny of leafcutter ants in the genus Atta Fabricius (Formicidae: Attini) based on mitochondrial and nuclear DNA sequences

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

Mechanisms of insulin secretion in malnutrition: modulation by amino acids in rodent models

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