Inheritance of resistance to Puccinia psidii G. Winter in a eucalyptus interspecific hybrid progeny evaluated under conditions of natural infection

A ferrugem, causada pelo fungo Puccinia psidii, é atualmente a mais importante doença do eucalipto. Esta doença está amplamente disseminada pelo Brasil e causa sérios danos em viveiros e plantações. A identificação de germoplasma resistente aliado ao conhecimento da base genética da resistência são os requerimentos primordiais para o sucesso de programas de melhoramento visando à produção de cultivares resistentes. Estudos anteriores sobre a herança da resistência em condições controladas sugerem tanto uma herança monogênica como a participação de pelo menos 2 genes conferindo resistência à doença. O objetivo deste estudo foi avaliar a resistência a P. psidii, em condições de campo em quatorze progênies obtidas a partir de cruzamentos e auto-cruzamentos controlados entre quatro clones híbridos de Eucalyptus grandis Hill ex Maiden x Eucalyptus urophylla ST Blake,que contrastam para a resistência ao fungo. Os resultados indicam que a resistência pode ser explicada por um loco com efeito principal e pelo menos três alelos diferentes, com interações entre os alelos, resultando no fenótipo de resistência ou suscetibilidade. Entretanto, locos com menor efeito devem influenciar a resistência, uma vez que foram observadas variações nas classes de severidade da escala utilizada. Nenhuma diferença na segregação para a resistência foi observada entre cruzamentos recíprocos, sugerindo que não existe influência citoplasmática no controle deste caráter.Rust caused by the fungus Puccinia psidii is currently the most important disease of eucalyptus. It is widely disseminated in Brazil, and causes serious damage in nurseries and plantation areas. The identification of resistant germplasm along with knowledge of the genetic basis of resistance heredity are the first requirements for the success of breeding programs aiming to develop resistant varieties. Earlier studies carried out under controlled conditions suggested a monogenic control as well as the participation of at least two genes promoting resistance to rust. The goal of this study was to evaluate the resistance to P. psidii under field conditions in fourteen progenies from controlled crosses and self-crosses among four hybrid clones of Eucalyptus grandis Hill ex Maiden x Eucalyptus urophylla ST Blake that contrast for resistance to the fungus. Results indicated that resistance could be explained by one locus with main effects and at least three different alleles. However, loci with minor effects may influence the resistance, since variation on severity classes was observed. Differences in segregation of resistance between reciprocal crosses were not observed, indicating absence of cytoplasmic effects.Votorantim Celulose e PapelConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Detection and Confirmation of Ractopamine and Its Metabolites in Horse Urine after Paylean® Administration

We have investigated the detection, confirmation, and metabolism of the beta-adrenergic agonist ractopamine administered as Paylean to the horse. A Testing Components Corporation enzyme-linked imunosorbent assay (ELISA) kit for ractopamine displayed linear response between 1.0 and 100 ng/ml, with an 1-50 of 10 ng/ml, and an effective screening limit of detection of 50 ng/mL. The kit was readily able to detect ractopamine equivalents in unhydrolyzed urine up to 24 h following a 300-mg oral dose. Gas chromatography-mass spectrometry (GC-MS) confirmation comprised glucuronidase treatment, solid-phase extraction, and trimethylsilyl derivatization, with selected-ion monitoring of ractopamine-tris(trimethylsilane) (TMS) m/z 267, 250, 179, and 502 ions. Quantitation was elaborated in comparison to a 445 Mw isoxsuprine-bis(TMS) internal standard monitored simultaneously. The instrumental limit of detection, defined as that number of ng on column for which signal-to-noise ratios for one or more diagnostic ions fell below a value of three, was 0.1 ng, corresponding to roughly 5 ng/mL in matrix. Based on the quantitation ions for ractopamine standards extracted from urine, standard curves showed a linear response for ractopamine concentrations between 10 and 100 ng/mL with a correlation coefficient r \u3e 0.99, whereas standards in the concentration range of 10-1000 ng/mL were fit to a second-order regression curve with r \u3e 0.99. The lower limit of detection for ractopamine in urine, defined as the lowest concentration at which the identity of ractopamine could be confirmed by comparison of diagnostic MS ion ratios, ranged between 25 and 50 ng/mL. Urine concentration of parent ractopamine 24 h post-dose was measured at 360 ng/mL by GC-MS after oral administration of 300 mg. Urinary metabolites were identified by electrospray ionization (+) tandem quadrupole mass spectrometry and were shown to include glucuronide, methyl, and mixed methyl-glucuronide conjugates. We also considered the possibility that an unusual conjugate added 113 amu to give an observed m/z 415 [M+H] species or two times 113 amu to give an m/z 528 [M+H] species with a daughter ion mass spectrum related to the previous one. Sulfate and mixed methyl-sulfate conjugates were revealed following glucuronidase treatment, suggesting that sulfation occurs in combination with glucuronidation. We noted a paired chromatographic peak phenomenon of apparent ractopamine metabolites appearing as doublets of equivalent intensity with nearly identical mass spectra on GC-MS and concluded that this phenomenon is consistent with Paylean being a mixture of RR, RS, SR, and SS diastereomers of ractopamine. The results suggest that ELISA-based screening followed by glucuronide hydrolysis, parent drug recovery, and TMS derivatization provide an effective pathway for detection and GC-MS confirmation of ractopamine in equine urine

Development of a method for the detection and confirmation of the alpha-2 agonist amitraz and its major metabolite in horse urine

Amitraz (N′-(2,4-dimethylphenyl)-N-[[(2,4-dimethylphenyl)imino] methyl]-N-methyl-methanimidamide) is an alpha-2 adrenergic agonist used in veterinary medicine primarily as a scabicide- or acaricide-type insecticide. As an alpha-2 adrenergic agonist, it also has sedative/tranquilizing properties and is, therefore, listed as an Association of Racing Commissioners International Class 3 Foreign Substance, indicating its potential to influence the outcome of horse races. We identified the principal equine metabolite of amitraz as N-2,4-dimethylphenyl-N′-methylformamidine by electrospray ionization(+)-mass spectrometry and developed a gas chromatographic-mass spectrometric (GC-MS) method for its detection, quantitation, and confirmation in performance horse regulation. The GC-MS method involves derivatization with t-butyldimethylsilyl groups; selected ion monitoring (SIM) of m/z 205 (quantifier ion), 278, 261, and 219 (qualifier ions); and elaboration of a calibration curve based on ion area ratios involving simultaneous SIM acquisition of an internal standard m/z 208 quantifier ion based on an in-house synthesized d6 deuterated metabolite. The limit of detection of the method is approximately 5 ng/mL in urine and is sufficiently sensitive to detect the peak urinary metabolite at 1 h post dose, following administration of amitraz at a 75-mg/horse intraveneous dose

Activation of leukocyte rolling by the cysteine-rich domain and the hyper-variable region of HF3, a snake venom hemorrhagic metalloproteinase

AbstractThe functionality of the disintegrin-like/cysteine-rich domains of snake venom metalloproteinases (SVMPs) has been shown to reside in the cysteine-rich region, which can interact with VWA-containing proteins. Recently, the hyper-variable region (HVR) of the cysteine-rich domain was suggested to constitute a potential protein–protein adhesive interface. Here we show that recombinant proteins of HF3, a hemorrhagic P-III SVMP, containing the cysteine-rich domain (disintegrin-like/cysteine-rich and cysteine-rich proteins) but not the disintegrin-like protein were able to significantly increase leukocyte rolling in the microcirculation. Peptides from the HVR also promoted leukocyte rolling and this activity was inhibited by anti-alphaM/beta2 antibodies. These results show, for the first time, that the cysteine-rich domain and its HVR play a role in triggering pro-inflammatory effects mediated by integrins

Avaliação ambiental do rio mongaguá, sp, utilizando macroinvertebrados bentônicos

Estudar a qualidade ambiental de um corpo d’água leva ao conhecimento da qualidade ambiental do seu entorno. Uma das comunidades biológicas muito estudada, neste sentido, é o grupo dos macroinvertebrados bentônicos, seres com dimensões entre milímetros e centímetros que habitam o sedimento do fundo dos corpos d’água. Segundo a literatura, muitos invertebrados macroscópicos são usados para diagnosticar a saúde de rios e lagos. O presente trabalho buscou compreender a qualidade das águas do Rio Mongaguá, SP, através da análise de parâmetros físicos, químicos e biológicos, utilizando a contagem e identificação de macroinvertebrados bentônicos em dois pontos do Rio Mongaguá, e um terceiro ponto em um afluente localizado na divisa entre Praia Grande e Mongaguá, os pontos foram denominados 1, 2 e 3. Os resultados das análises químicas e físicas demonstraram o pH e turbidez dentro dos valores referências para águas doces de classe 2 da resolução CONAMA 357/05. No ponto 1 foram encontrados organismos Chironomidae, que possuem resistência para sobreviver em águas com baixos níveis de oxigênio. Este ponto apresentava grande quantidade de lixo como garrafas plásticas e restos de alimentos. Não foi possível determinar a qualidade ambiental do ponto 2, pois o único organismo encontrado não foi identificado. Os organismos encontrados no ponto 3, dos grupos Plecoptera, Trichoptera, Ephemeroptera e Lepdoptera, habitam águas limpas com alto índice de oxigênio, podendo-se inferir que, neste ponto, a qualidade da água era boa. &nbsp

Transcript levels of ten caste-related genes in adult diploid males of Melipona quadrifasciata (Hymenoptera, Apidae) - A comparison with haploid males, queens and workers

In Hymenoptera, homozygosity at the sex locus results in the production of diploid males. In social species, these pose a double burden by having low fitness and drawing resources normally spent for increasing the work force of a colony. Yet, diploid males are of academic interest as they can elucidate effects of ploidy (normal males are haploid, whereas the female castes, the queens and workers, are diploid) on morphology and life history. Herein we investigated expression levels of ten caste-related genes in the stingless bee Melipona quadrifasciata, comparing newly emerged and 5-day-old diploid males with haploid males, queens and workers. In diploid males, transcript levels for dunce and paramyosin were increased during the first five days of adult life, while those for diacylglycerol kinase and the transcriptional co-repressor groucho diminished. Two general trends were apparent, (i) gene expression patterns in diploid males were overall more similar to haploid ones and workers than to queens, and (ii) in queens and workers, more genes were up-regulated after emergence until day five, whereas in diploid and especially so in haploid males more genes were down-regulated. This difference between the sexes may be related to longevity, which is much longer in females than in males

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors