21 research outputs found

    The FunGenES Database: A Genomics Resource for Mouse Embryonic Stem Cell Differentiation

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    Embryonic stem (ES) cells have high self-renewal capacity and the potential to differentiate into a large variety of cell types. To investigate gene networks operating in pluripotent ES cells and their derivatives, the “Functional Genomics in Embryonic Stem Cells” consortium (FunGenES) has analyzed the transcriptome of mouse ES cells in eleven diverse settings representing sixty-seven experimental conditions. To better illustrate gene expression profiles in mouse ES cells, we have organized the results in an interactive database with a number of features and tools. Specifically, we have generated clusters of transcripts that behave the same way under the entire spectrum of the sixty-seven experimental conditions; we have assembled genes in groups according to their time of expression during successive days of ES cell differentiation; we have included expression profiles of specific gene classes such as transcription regulatory factors and Expressed Sequence Tags; transcripts have been arranged in “Expression Waves” and juxtaposed to genes with opposite or complementary expression patterns; we have designed search engines to display the expression profile of any transcript during ES cell differentiation; gene expression data have been organized in animated graphs of KEGG signaling and metabolic pathways; and finally, we have incorporated advanced functional annotations for individual genes or gene clusters of interest and links to microarray and genomic resources. The FunGenES database provides a comprehensive resource for studies into the biology of ES cells

    Combining Chimeric Mice with Humanized Liver, Mass Spectrometry, and Physiologically-Based Pharmacokinetic Modeling in Toxicology

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    Species differences exist in terms of drug oxidation activities, which are mediated mainly by cytochrome P450 (P450) enzymes. To overcome the problem of species extrapolation, transchromosomic mice containing a human P450 3A cluster or chimeric mice transplanted with human hepatocytes have been introduced into the human toxicology research area. In this review, drug metabolism and disposition mediated by humanized livers in chimeric mice are summarized in terms of biliary/urinary excretions of phthalate and bisphenol A and plasma clearances of the human cocktail probe drugs caffeine, warfarin, omeprazole, metoprolol, and midazolam. Simulation of human plasma concentrations of the teratogen thalidomide and its human metabolites is possible with a simplified physiologically based pharmacokinetic model based on data obtained in chimeric mice, in accordance with reported clinical thalidomide concentrations. In addition, <i>in vivo</i> nonspecific hepatic protein binding parameters of metabolically activated <sup>14</sup>C-drug candidate and hepatotoxic medicines in humanized liver mice can be analyzed by accelerator mass spectrometry and are useful for predictions in humans

    Pollination of soybean (Glycine max L. Merril) by honeybees (Apis mellifera L.)

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    This experiment was carried out to evaluate the effect of the honeybee pollination in the production and quality of soybean seeds (Glycine max L. Merril). Seed production was higher (P=0.0001) in covered areas with honeybee colonies (50.64%) and uncovered areas (57.73%) than in covered areas without honeybee colonies. It could be concluded that honeybees were responsible for 95.5% of the pollination accomplished by insects. The pod number in covered treatment with honeybees was 61.38% higher (P=0.0002) than in the covered treatment without honeybees. The average weight of 100 seeds was larger (P=0.0001) in the area covered without honeybees, and reached 17.8 g. The medium content of crude protein in grains was 36.7% and the average oil content was 20.2%. The germination test did not show differences (P>0.05) among the seeds in different treatments. It was concluded that the honeybee pollination in the soybean increased the seeds production

    Sugar content in nectar flowers of siratro (Macroptilium atropurpureum Urb.) - DOI: 10.4025/actascianimsci.v27i1.1248

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    Siratro (Macroptilium atropurpureum Urb.) é uma planta forrageira com alto valor nutricional e excelente palatabilidade, sua fenologia é pouco conhecida. Objetivando melhorar o conhecimento e compreensão dos polinizadores do siratro e sua biologia floral, o conteúdo de açúcares totais no néctar de suas flores e a identificação desses açúcares foram determinados por espectrofotometria e cromatografia, respectivamente. A concentração de açúcares totais variou de 1,36 a 3,23 mg/flor para o valor máximo e de 0,19 a 0,42 mg/flor para o valor mínimo. Os resultados mostraram que a concentração de açúcares totais é alta às 8h30min, quando as flores estão abertas e varia um pouco durante o tempo que as flores permanecem abertas. A variação pode estar relacionada ao número de insetos que visitam as flores, especialmente as abelhas que podem coletar pólen e néctar durante o período de antese (8h30min às 16h30min). Por meio de análise enzimática, foi verificado que o siratro possui somente a glicose na sua composiçãoSiratro (Macroptilium atropurpureum Urb.) is a forager with high nutritional values and excellent palatability, and its phenology is almost unknown. Aiming at improving the knowledge and understanding siratro pollinators and floral biology, the total sugar contents on its flowers nectar and the identification of these sugars were determined by, respectively, spectrophotometry and chromatography. The total sugar concentration varied from a maximum of 1.36 and 3.23 mg/flower and a minimum of 0.19 and 0.42 mg/flower. Results showed that the total sugar concentration is high at 8:30 a.m., when the flowers open, and varies slightly during the time the flowers keep open. The variations can be related to the number of insects that visit the flowers, especially bees that may collect pollen and nectar during the open period (8:30 a.m. to 4:30 p.m.). Through enzymatic analysis, data showed that siratro has only glucose in its compositio

    Biologia floral e polinização por abelhas em siratro (Macroptilium atropurpureum Urb.)

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    This research was carried out to evaluate the pollination in siratro studying the anthesis period, pollen grain viability and seed production. Two treatments were used, one covered and another uncovered. The anthesis period was 2.48 days and 3.56 days (p = 0.0001) and the production was 8.62 and 11.15 seeds (p = 0.0023), in covered and uncovered treatments, respectively. The stigma receptivity test showed that 91.95% of opened flowers were receptive. Pollen grains viability was 100%. In Brazil, there are six families of bees and we have found five of them in Maringá region visiting the flowers of this plant: Apidae (56%), Megachilidae (12%), Halictidae (16%), Andrenidae (12%) and Anthophoridae (4%). Results showed that the flowers of siratro are important as pollen and nectar source for bees which contribute to its pollination.O objetivo deste trabalho foi realizar estudos sobre polinização em siratro, avaliando o período de antese, abelhas visitantes, viabilidade dos grãos de pólen e produção de sementes, utilizando dois tratamentos, um de plantas cobertas e outro de descobertas. O período de antese foi 2,48 dias e 3,56 dias (P = 0,0023) e a produção foi de 8,62 e 11,15 sementes (P = 0,0001), para os tratamentos descoberto e coberto, respectivamente. O teste de receptividade do estigma indicou que 91,95% das flores abertas estavam receptivas. A viabilidade dos grãos de pólen foi 100%. Das seis famílias de abelhas que ocorrem no Brasil, foram encontradas cinco delas visitando as flores desta planta: Andrenidae (12%), Anthophoridae (4%), Apidae (56%), Halictidae (16%) e Megachilidae (12%). Pode-se concluir que as flores de siratro são importantes fontes de pólen e néctar para as abelhas que contribuem para a polinização desta planta
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