56 research outputs found

    Outbreak of Lauritrioza alacris (Flor, 1861) (Hemiptera, Triozidae) in a commercial plantation of bay laurel (Laurus nobilis L., Lauraceae) in Brazil.

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    An attack of Lauritrioza alacris (Flor, 1861) (Hemiptera: Triozidae) was recorded in a commercial plantation of bay laurel (Laurus nobilis L., Lauraceae) in the municipality of Dois Lajeados, Rio Grande do Sul state (RS), Brazil. The immature triozids induced galls on the attacked leaves consisting of the thickened margins that became folded downward, forming an elongated tube-shaped roll that sheltered the immatures. All developmental stages (egg, immatures, and adults) of the psyllid were found on young leaves of bay laurel. Lauritrioza alacris is an introduced pest in Brazil that was detected in Pelotas, RS in 1949 and Rio de Janeiro, Rio de Janeiro state in 1953. Therefore, we are reporting the third record of L. alacris; however, it is the first documented information of an infestation in a commercial bay laurel plantations by L. alacris in Brazil. Information on taxonomy, biological aspects, distribution, and damage caused by the laurel psyllid is also provided

    Sipha maydis (Hemiptera: Aphididae) in the humid subtropical region of Brazil: distribution, seasonality and biology.

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    Abstract: Sipha maydis (Passerini) (Hemiptera: Aphididae) is a pest of cultivated cereals and wild grasses introduced into America and first reported in South America at Argentina in 2002. In Brazil, this aphid was detected first in wheat in Oct 2006 at Rio Grande do Sul State. Between 2007 and 2013 the aphid was reported in several localities in the humid subtropical region of Brazil (southern states of Rio Grande do Sul, Santa Catarina, and Paraná) on different plant species including Triticum aestivum L., Avena strigosa Schreb., Lolium multiflorum Lam., Hordeum vulgare L., Zea mays L. (all Poaceae) and uncultivated grasses. Sipha maydis also has been captured in yellow tray traps. Peak flight activity for S. maydis occurred in the spring-summer transition and was apparently correlated with average air temperature. Sipha maydis was able to complete its life cycle on A. strigosa, L. multiflorum, H. vulgare, Z. mays, and T. aestivum. During the nymphal phase the best hosts were A. strigosa, L. multiflorum, H. vulgare, and T. aestivum. Hordeum vulgare and T. aestivum were the best for the reproductive period and longevity. The intrinsic rate of increase was greatest on A. strigosa, L. multiflorum, and T. aestivum. Generation time was longer on H. vulgare, Z. mays, and T. aestivum. Net rate reproduction was greater in H. vulgare and T. aestivum, and the finite rate of increase was greatest on A. strigosa, L. multiflorum, H. vulgare, and T. aestivum. Although the distribution of S. maydis is expanding and covering the main wheat-growing region of Brazil, and despite the wide range of hosts and the direct damage it causes to local foraging sites, aphid populations are low and their economic importance is limited. However, it reveals that S. maydis has the potential to colonize subtropical regions. Resumo: Sipha maydis (Passerini) é uma praga de cereais cultivados e gramíneas silvestres introduzida na América e relatada pela primeira vez na América do Sul na Argentina em 2002. No Brasil, o pulgão-preto-dos-cereais foi detectado pela primeira vez em Triticum aestivum L. em outubro de 2006 no Estado do Rio Grande do Sul. Entre 2007 e 2013, o pulgão foi relatado em várias localidades da região subtropical húmida do Brasil (Estados da Região Sul: Rio Grande do Sul, Santa Catarina e Paraná) em diferentes espécies de plantas como T. aestivum, Avena strigosa Schreb., Lolium multiflorum Lam., Hordeum vulgare L., Zea mays L. (todas Poaceae), e gramíneas não cultivadas. Sipha maydis também foi capturado em armadilhas do tipo bandeja amarela para pulgões alados. O pico de ocorrência das formas aladas na transição primavera-verão é aparentemente correlacionado com a temperatura média do ar. S. maydis foi capaz de completar o ciclo de vida em A. strigosa, L. multiflorum, H. vulgare, Z. mays, e T. aestivum. Durante a fase de ninfa, os melhores hospedeiros foram A. strigosa, L. multiflorum, H. vulgare, e T. aestivum. A H. vulgare e o T. aestivum foram os melhores para o período reprodutivo e longevidade. A taxa intrínseca de aumento foi grande em A. strigosa, L. multiflorum, e T. aestivum; o tempo de uma geração foi mais longo em H. vulgare, Z. mays, e T. aestivum; a taxa líquida de reprodução foi ótima em H. vulgare e em T. aestivum e a taxa de aumento finito foi grande em A. strigosa, L. multiflorum, H. vulgare, e T. aestivum. Embora a distribuição de S. maydis esteja se expandindo e cobrindo a principal região tritícola do Brasil, e a despeito da ampla gama de hospedeiros e dos danos diretos que causa aos sítios de alimentação, as populações de pulgões são baixas e sua importância econômica ainda é limitada. No entanto, revela que S. maydis tem potencial para colonizar regiões subtropicais

    Resveratrol and Endometrium: A Closer Look at an Active Ingredient of Red Wine Using In Vivo and In Vitro Models

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    Resveratrol is a natural phytoestrogen with antiproliferative properties present in red wine, grapes, and berries. Published reports on the effects of resveratrol in human endometrial function are limited. The objective of this study was to investigate the expression of estrogen receptor α (ESR1), Ki-67 (a proliferative marker), aryl hydrocarbon receptor (AhR), and members of the cytochrome P450 superfamily of enzymes (CYP1A1 and CYP1B1) in an in vitro and vivo assay. Alkaline phosphatase assay of estrogenicity was used to compare estrogen activity of different concentrations of resveratrol to estradiol (E2) and diethylstilbestrol (DES), using Ishikawa cell culture. Immunohistochemical expression of ESR1 and Ki67, and reverse transcriptase polymerase chain reaction of AhR, CYP1A1, and CYP1B1 were analyzed from xenograft implants of human endometrial tissue in ovariectomized immunodeficient RAG-2-γ(c) mice, after 30 days of treatment with subcutaneous pellets of E2, E2 plus progesterone (P4), or E2 plus resveratrol (6, 30, or 60 mg) for 30 days. Compared to E2, resveratrol acted as an agonist and antagonist of estrogen in low and high concentrations, respectively, when combined with E2. Xenografts of human endometrial tissues in RAG-2 mice exhibited reduced expression of ESR1 and proliferative activity (Ki67) with 60 mg of resveratrol. This study suggests that resveratrol, at high doses, has the potential benefit to reduce proliferation of human endometrium through ESR1

    Integrative approach reveals the identity of Brazilian specimens previously recognized as Anastrepha dissimilis Stone, 1942 (Diptera: Tephritidae).

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    Anastrepha dissimilis is currently considered to be widely distributed in Brazil, occurring in 20 of 27 states. However, morphological differences between the holotype (from Plaisance, Haiti) and a paratype (from Pernambuco, Brazil) suggest that the Brazilian specimens are not A. dissimilis, because their aculeus tip is similar to the paratype not to the holotype. Therefore, considering the importance of integrative taxonomy for species delimitation, we used geometric and linear morphometrics and cytochrome c oxidase subunit I sequences integrated with the morphology of the aculeus tip to clarify the identity of populations previously identified as A. dissimilis from multiple Brazilian localities. Morphological data show a uniform pattern among the Brazilian populations, with some variation among specimens from the south and northeast. In addition, the geometric and linear morphometrics suggest considerable geographic variation among these populations, suggesting the existence of at least two morphs. The molecular analysis revealed that specimens from Brazil previously identified as A. dissimilis belong to Anastrepha chiclayae Greene, with a genetic distance ranging from 0.00 to 0.015%. According to our integrative analyses, specimens from Brazil formerly identified as A. dissimilis actually are A. chiclayae. Therefore, this is the first record of A. chiclayae in Brazil, and we also report that A. dissimilis does not occur in Brazil

    DIMBOA levels in hexaploid Brazilian wheat are not associated with antibiosis against the cereal aphids Rhopalosiphum padi and Sitobion avenae.

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    The objective of this study was to evaluate the natural levels of the plant defence compound DIMBOA in young leaves of eight hexaploid Brazilian wheat genotypes and the impact of the genotypes upon development of cereal aphids, Rhopalosiphum padi and Sitobion avenae. HPLC Analysis revealed that the DIMBOA levels varied from 5.376 (in BRS Guabiju) to 30.651 mmol/kgFW (in BRS Timbaúva) with two genotypes outperforming Solstice, a UK variety used as reference. Bioassays were conducted to evaluate the development and fecundity of both aphids when grown on the wheat genotypes. Although BRS Guabiju and BRS Timbaúva were among the genotypes showing the highest and lowest susceptibility respectively, against both aphids, no correlation could be found between DIMBOA levels and antibiosis effects. The cultivar BRS 327 that was among the genotypes showing lower intrinsic rate of population increase for the two aphid species. Elucidating the role of secondary metabolites in plant resistance to aphids and the characterisation of the genotypes that allowed reduced aphid development are important steps to achieve a better natural resistance in hexaploid Brazilian wheat

    Molecular mechanisms in uterine epithelium during trophoblast binding: the role of small GTPase RhoA in human uterine Ishikawa cells

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    BACKGROUND: Embryo implantation requires that uterine epithelium develops competence to bind trophoblast to its apical (free) poles. This essential element of uterine receptivity seems to depend on a destabilisation of the apico-basal polarity of endometrial epithelium. Accordingly, a reorganisation of the actin cytoskeleton regulated by the small GTPase RhoA plays an important role in human uterine epithelial RL95-2 cells for binding of human trophoblastoid JAR cells. We now obtained new insight into trophoblast binding using human uterine epithelial Ishikawa cells. METHODS: Polarity of Ishikawa cells was investigated by electron microscopy, apical adhesiveness was tested by adhesion assay. Analyses of subcellular distribution of filamentous actin (F-actin) and RhoA in apical and basal cell poles were performed by confocal laser scanning microscopy (CLSM) with and without binding of JAR spheroids as well as with and without inhibition of small Rho GTPases by Clostridium difficile toxin A (toxin A). In the latter case, subcellular distribution of RhoA was additionally investigated by Western blotting. RESULTS: Ishikawa cells express apical adhesiveness for JAR spheroids and moderate apico-basal polarity. Without contact to JAR spheroids, significantly higher signalling intensities of F-actin and RhoA were found at the basal as compared to the apical poles in Ishikawa cells. RhoA was equally distributed between the membrane fraction and the cytosol fraction. Levels of F-actin and RhoA signals became equalised in the apical and basal regions upon contact to JAR spheroids. After inhibition of Rho GTPases, Ishikawa cells remained adhesive for JAR spheroids, the gradient of fluorescence signals of F-actin and RhoA was maintained while the amount of RhoA was reduced in the cytosolic fraction with a comparable increase in the membrane fraction. CONCLUSION: Ishikawa cells respond to JAR contact as well as to treatment with toxin A with rearrangement of F-actin and small GTPase RhoA but seem to be able to modify signalling pathways in a way not elucidated so far in endometrial cells. This ability may be linked to the degree of polar organisation observed in Ishikawa cells indicating an essential role of cell phenotype modification in apical adhesiveness of uterine epithelium for trophoblast in vivo
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