The nitrate transporter family protein LjNPF8.6 controls the N-fixing nodule activity

N-fixing nodules are new organs formed on legume roots as a result of the beneficial interaction with soil bacteria, rhizobia. The nodule functioning is still a poorly characterized step of the symbiotic interaction, as only a few of the genes induced in N-fixing nodules have been functionally characterized. We present here the characterization of a member of the Lotus japonicus nitrate transporter1/peptide transporter family, LjNPF8.6. The phenotypic characterization carried out in independent L. japonicus LORE1 insertion lines indicates a positive role of LjNPF8.6 on nodule functioning, as knockout mutants display N-fixation deficiency (25%) and increased nodular superoxide content. The partially compromised nodule functioning induces two striking phenotypes: anthocyanin accumulation already displayed 4 weeks after inoculation and shoot biomass deficiency, which is detected by long-term phenotyping. LjNPF8.6 achieves nitrate uptake in Xenopus laevis oocytes at both 0.5 and 30 mm external concentrations, and a possible role as a nitrate transporter in the control of N-fixing nodule activity is discussed

Identification of the production system of beef cattle by the stable isotope analysis

O objetivo deste trabalho foi avaliar o potencial da técnica de isótopos estáveis para caracterizar sistemas de produção de carne bovina em condições tropicais. Para tanto, foram identificados isótopos estáveis de carbono e nitrogênio em músculos de bovinos não desengordurados e desengordurados. Avaliaram-se 45 bovinos criados em três sistemas de produção: a pasto, confinamento convencional e confinamento de novilhos superprecoces (n= 15 por sistema). Amostras dos músculos Trapezius cervicis, Longissimus dorsi e Semitendinosus foram coletadas para determinar a composição isotópica de δ13C e δ15N. Os dados isotópicos de δ13C e δ15N em músculos não desengordurados e desengordurados foram submetidos à análise de componentes principais (ACP) e à análise discriminante (AD). A ACP permitiu a separação dos três sistemas de produção com base nos resultados obtidos para os músculos não desengordurados e desengordurados. Obtiveram-se uma taxa de classificação correta geral de 100% e uma taxa de validação cruzada de 100% com a AD. A razão isotópica de carbono e nitrogênio em músculos não desengordurados e desengordurados permite identificar com precisão os sistemas de produção de bovinos de corte em condições tropicais.The objective of this work was to evaluate the potential of the stable isotope technique to characterize beef cattle production systems in tropical conditions. For this, carbon and nitrogen stable isotopes were identified in non-defatted and defatted bovine muscles. A total of 45 cattle were evaluated in three production systems: pasture, conventional feedlot, and young beef bull feedlot (n = 15 per system). Samples from the Trapezius cervicis, Longissimus dorsi, and Semitendinosus muscles were collected to determine the isotopic composition of δ13C and δ15N. The isotopic data of the δ13C and δ15N of non-defatted and defatted muscles were subjected to the principal component analysis (PCA) and to the discriminant analysis (DA). The PCA allowed separating the three production systems based on the results obtained for the non-defatted and defatted muscles. A correct global classification rate of 100% and a cross-validation rate of 100% were obtained with the DA. The carbon and nitrogen isotopic ratio of non-defatted and defatted muscles allows for the precise identification of beef cattle production systems in tropical conditions

Multiplex PCR identification of eight clinically relevant Candida species

Invasive fungal infections, specifically candidemia, constitute major public health problems with high mortality rates. Therefore, in the last few years, the development of novel diagnostic methods has been considered a critical issue. Herein we describe a multiplex PCR strategy allowing the identification of 8 clinically relevant yeasts of the Candida genus, namely C. albicans, C. glabrata, C. parapsilosis, C. tropicalis, C. krusei, C. guilliermondii, C. lusitaniae and C. dubliniensis. This method is based on the amplification of two fragments from the ITS1 and ITS2 regions by the combination of 2 yeast-specific and 8 species-specific primers in a single PCR reaction. Results from the identification of 231 clinical isolates are presented pointing to the high specificity of this procedure. Furthermore, several Candida isolates were identified directly from clinical specimens which also attests to the method's direct laboratory application. The results from the multiplex reactions with other microorganisms that usually co-infect patients also confirmed its high specificity in the identification of Candida species. Moreover, this method is simple and presents a sensitivity of approximately 2 cells per ml within 5 hours. Furthermore, it allows discrimination of individual Candida species within polyfungal samples. This novel method may therefore provide a clinical diagnostic procedure with direct applicability.Agostinho Carvalho was financially supported by a fellowship from Fundação para a Ciência e Tecnologia, Portugal (contract SFRH/BD/11837/2003). This study was supported by Fundação para a Ciência e Tecnologia, Portugal (POCI/SAU-ESP/61080/2004)

Genome size and ploidy of Paracoccidioides brasiliensis reveals a haploid DNA content: Flow cytometry and GP43 sequence analysis

The aim of this study was to evaluate genome size and ploidy of the dimorphic pathogenic fungus Paracoccidioides brasiliensis. The cell cycle analysis of 10 P. brasiliensis isolates by flow cytometry (FCM) revealed a genome size ranging from 26.3+/-0.1Mb (26.9+/-0.1fg) to 35.5+/-0.2Mb (36.3+/-0.2fg) per uninucleated yeast cell. The DNA content of conidia from P. brasiliensis ATCC 60855-30.2+/-0.8Mb (30.9+/-0.8fg) -showed no significant differences with the yeast form, possibly excluding the occurrence of ploidy shift during morphogenesis. The ploidy of several P. brasiliensis isolates was assessed by comparing genome sizing by FCM with the previously described average haploid size obtained from electrophoretic karyotyping. The analysis of intra-individual variability of a highly polymorphic P. brasiliensis gene, GP43, indicated that only one allele seems to be present. Overall, the results showed that all analysed isolates presented a haploid, or at least aneuploid, DNA content and no association was detected between genome size/ploidy and the clinical-epidemiological features of the studied isolates. This work provides new knowledge on P. brasiliensis genetics/genomics, important for future research in basic cellular/molecular mechanisms and for the development/design of molecular techniques in this fungus

Ultra-sonografia para predição das características da carcaça de bovinos jovens em confinamento

Considerable resources have been allocated to support research in the development of non-invasive and non-destructive techniques for carcass composition and quality evaluation. Ultrasonography is a reliable and relatively low-cost technique that can be used. In the present study, real-time ultrasonography was used to predict ribeye area (REA) and subcutaneous fat thickness (FT) in live animals as compared to carcass measurements. Animals used were 115 yearling bull calves (initial body weight, 329 kg), kept under feedlot conditions, of four genetic groups (30, ½ Angus x Nellore; 30, ½ Canchim x Nellore; 30, ½ Simmental x Nellore, and 25 Nellore), and two finishing frame sizes (small and large). Four ultrasonographic measurements were taken every 28 days until slaughter. Predictive precision of ultrasonographic measurements increased as animals approached slaughter, reaching maximum values at the last measurement (R²=0.68 and 0.82 for REA and FT, respectively). FT carcass measurements was influenced by genetic group and live measurements (P < 0.05). Frame size did not influence REA and FT, probably due to small, but distinctive differences among genetic groups.O desenvolvimento de técnicas não invasivas e não destrutivas para a avaliação da composição e qualidade de carcaça em animais tem mobilizado consideráveis recursos em pesquisa. A ultra-sonografia aparece neste contexto como uma técnica viável, confiável e de custo aceitável para esta função. No presente trabalho foi avaliada a técnica de ultra-sonografia em tempo real como ferramenta para predição da área de olho-de-lombo (AOL) e espessura da camada de gordura subcutânea (ECG) a partir de imagens tomadas em animais vivos, quando comparadas com as medições na carcaça. Foram utilizados 115 bovinos jovens (30, ½ Angus x Nellore; 30, ½ Canchim x Nellore; 30, ½ Simental x Nellore, e 25 Nellores), com peso inicial médio de 329 kg e de dois tamanhos à maturidade (pequeno e grande), no sistema de produção do novilho superprecoce. As medidas de ultra-sonografia foram realizadas a cada 28 dias totalizando quatro medições até o final do confinamento. A precisão da predição aumentou em função da proximidade da data do abate, sendo máxima na quarta medida (R²= 0,68 para AOL e 0,82 para ECG). Houve efeito de grupo genético e de medida ultra-sonográfica para ECG. O tamanho corporal não teve efeito sobre nenhuma das características estudadas

Efeitos do fornecimento de agonistas β-adrenérgicos no desempenho produtivo, características de carcaça e qualidade da carne de bovinos confinados

To enhance the efficiency of production of beef, some countries use &beta;-adrenergics, promoters of non-hormonal growth, on final phase of beef cattle. These substances are chemically and pharmacologically similar to the natural catecholamines (dopamine, noreprinephrine and eprinephrine) and promote an increase of the deposition rate of muscle tissue, with consequent decrease in the deposition of adipose tissue. The &beta;-adrenergic most used in beef cattle are ractopamine hydrochloride and zilpaterol hydrochloride. These products should only be used in confined cattle during the finishing period. According to studies, there are various effects of administration of &beta;-adrenergic for beef cattle. The main effects are increased muscle mass, with consequent increase of the carcass weight, weight gain and feed conversion. Greater carcass yield, larger loin eye area and larger diameter of the muscle fibers of the meat were also observed. In some studies, we obtained lower deposition of subcutaneous and visceral fat and lower marbling score in beef.Para aumentar a efici&ecirc;ncia da produ&ccedil;&atilde;o de carne bovina, alguns pa&iacute;ses utilizam agonistas &beta;-adren&eacute;rgicos, promotores de crescimento n&atilde;o-hormonais, na termina&ccedil;&atilde;o de bovinos de corte. Tais subst&acirc;ncias s&atilde;o semelhantes qu&iacute;mica e farmacologicamente &agrave;s catecolaminas naturais (dopamina, noreprinefrina e eprinefrina) e promovem um aumento na velocidade de deposi&ccedil;&atilde;o de tecido muscular, com consequente diminui&ccedil;&atilde;o na deposi&ccedil;&atilde;o do tecido adiposo. Os &beta;-adren&eacute;rgicos mais utilizados na bovinocultura de corte s&atilde;o cloridrato de ractopamina e cloridrato de zilpaterol. Estes produtos devem ser utilizados apenas na alimenta&ccedil;&atilde;o de bovinos confinados, durante o per&iacute;odo final de termina&ccedil;&atilde;o. Segundo estudos, s&atilde;o diversos os efeitos da administra&ccedil;&atilde;o de &beta;-adren&eacute;rgicos para bovinos. Os principais s&atilde;o aumento na produ&ccedil;&atilde;o de massa muscular, com consequente eleva&ccedil;&atilde;o no peso final da carca&ccedil;a, ganho em peso e convers&atilde;o alimentar. Tamb&eacute;m foram observados maior rendimento de carca&ccedil;a, maior &aacute;rea de olho de lombo e maior di&acirc;metro das fibras musculares da carne. Em alguns estudos, obteve-se menor deposi&ccedil;&atilde;o de gordura subcut&acirc;nea e visceral e menores escores de marmoreio na carne

Efeitos da suplementação com diferentes fontes de lipídeo na reatividade, estresse e concentrações plasmáticas de cortisol de bovinos confinados

This study aimed to evaluate the effects of diets supplemented with natural or r&uacute;men-protected lipid source on plasma cortisol concentration, animal reactivity and stress of feedlot cattle. One hundred and twenty Nellore bulls (366.9 &plusmn; 28.7), male, raised on pasture were distributed in a completely randomized design with measures repeated over time. There were three treatments: Control - without additional fat source; GDESP - with natural fat source based on cottonseed by-products; and GPROT - with r&uacute;men-protected polyunsaturated fat acid. Blood samples were collected before to boarding of animals (day 0) and after transport to the feedlot, on days 1, 3, 7 and 14. There was significant effect (p&lt;0.05) between temperament and day of analysis, as well as levels of cortisol and day of collection and treatment the animals received. On boarding day (day 0), the mean score of reactivity was lower (p&lt;0.05). On the day of landing (day 1), the animals showed less reactive (p&lt;0.05). In the following collection (days 3, 7 and 14), there was a progressive increase in mean scores for reactivity. The treatment did not influence the reactivity of animals. In relation to cortisol, the results were similar to reactivity. There was an effect (p&lt;0.05) between treatments with inclusion of protected fat and fat from natural sources, and the control group. Animals receiving lipids in the diet had lower cortisol levels compared to the control group.O objetivo deste estudo foi avaliar os efeitos da adi&ccedil;&atilde;o de lip&iacute;deos naturais e protegidos, na dieta de bovinos Nelore confinados, nas concentra&ccedil;&otilde;es plasm&aacute;ticas de cortisol e influ&ecirc;ncia sobre reatividade animal. Foram utilizados 120 bovinos (366,9 &plusmn; 28,7), machos, n&atilde;o castrados provenientes de recria em pasto. O delineamento experimental foi inteiramente casualizado com medidas repetidas no tempo, composto por tr&ecirc;s tratamentos: controle - sem fonte de lip&iacute;deo, GDESP - com fonte de lip&iacute;deo natural a base de co-produto do algod&atilde;o e GPROT - com fonte de lip&iacute;deo protegido rico em &aacute;cidos graxos poliinsaturados. Foram coletadas amostras de sangue antes do embarque dos animais (dia 0) e ap&oacute;s o transporte para o confinamento, nos dias 1, 3, 7 e 14. Houve efeito significativo (p&lt;0,05) entre o temperamento e dia da an&aacute;lise, assim como os n&iacute;veis de cortisol e dia da coleta e tratamento que os animais receberam. No dia do embarque (dia 0), a m&eacute;dia do escore de reatividade foi menor (p&lt;0,05). No dia do desembarque (dia 1), os animais se apresentaram menos reativos (p&lt;0,05). Nas coletas seguintes (dias 3, 7 e 14), houve um aumento progressivo na m&eacute;dia dos escores de reatividade. O tratamento n&atilde;o influenciou na reatividade dos animais. Em rela&ccedil;&atilde;o ao cortisol, os resultados foram semelhantes &agrave; reatividade. Houve efeito (p&lt;0,05) entre os tratamentos com inclus&atilde;o de gordura protegida e gordura de fontes naturais, e o grupo controle. Os animais que receberam lip&iacute;deos na dieta tiveram n&iacute;veis mais baixos de cortisol em rela&ccedil;&atilde;o ao grupo controle

Reactive oxygen species, ageing and the hormesis police

For more than 50 years, the free radical theory served as the paradigm guiding most investigations of ageing. However, recent studies in a variety of organisms have identified conceptual and practical limitations to this theory. Some of these limitations are related to the recent discovery that caloric restriction and other experimental manipulations promote longevity by inducing hormesis effects in association with increased reactive oxygen species (ROS). The beneficial role of ROS in lifespan extension is consistent with the essential role of these molecules in cell signalling. However, the identity of specific forms of ROS that promote longevity remains unclear. In this article, we argue that in several model systems, hydrogen peroxide plays a crucial role in the induction of hormesis.The authors wish to thank Molly Burhans for preparing the figures. This work was supported by Fundacao para a Ciencia e Tecnologia (FCT) and COMPETE/QREN/EU (PTDC/BIA-MIC/114116/2009), a grant from the Roswell Park Alliance Foundation and by a National Cancer Institute Support Grant (P30CA016056) to Roswell Park Cancer Institute. Authors have no conflict of interest to declare