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991.
992.
G protein-coupled receptors in Anopheles gambiae 总被引:3,自引:0,他引:3
Hill CA Fox AN Pitts RJ Kent LB Tan PL Chrystal MA Cravchik A Collins FH Robertson HM Zwiebel LJ 《Science (New York, N.Y.)》2002,298(5591):176-178
We used bioinformatic approaches to identify a total of 276 G protein-coupled receptors (GPCRs) from the Anopheles gambiae genome. These include GPCRs that are likely to play roles in pathways affecting almost every aspect of the mosquito's life cycle. Seventy-nine candidate odorant receptors were characterized for tissue expression and, along with 76 putative gustatory receptors, for their molecular evolution relative to Drosophila melanogaster. Examples of lineage-specific gene expansions were observed as well as a single instance of unusually high sequence conservation. 相似文献
993.
Lyall J Irvine RM Sherman A McKinley TJ Núñez A Purdie A Outtrim L Brown IH Rolleston-Smith G Sang H Tiley L 《Science (New York, N.Y.)》2011,331(6014):223-226
Infection of chickens with avian influenza virus poses a global threat to both poultry production and human health that is not adequately controlled by vaccination or by biosecurity measures. A novel alternative strategy is to develop chickens that are genetically resistant to infection. We generated transgenic chickens expressing a short-hairpin RNA designed to function as a decoy that inhibits and blocks influenza virus polymerase and hence interferes with virus propagation. Susceptibility to primary challenge with highly pathogenic avian influenza virus and onward transmission dynamics were determined. Although the transgenic birds succumbed to the initial experimental challenge, onward transmission to both transgenic and nontransgenic birds was prevented. 相似文献
994.
Heisler LK Cowley MA Tecott LH Fan W Low MJ Smart JL Rubinstein M Tatro JB Marcus JN Holstege H Lee CE Cone RD Elmquist JK 《Science (New York, N.Y.)》2002,297(5581):609-611
D-fenfluramine (d-FEN) was once widely prescribed and was among the most effective weight loss drugs, but was withdrawn from clinical use because of reports of cardiac complications in a subset of patients. Discerning the neurobiology underlying the anorexic action of d-FEN may facilitate the development of new drugs to prevent and treat obesity. Through a combination of functional neuroanatomy, feeding, and electrophysiology studies in rodents, we show that d-FEN-induced anorexia requires activation of central nervous system melanocortin pathways. These results provide a mechanistic explanation of d-FEN's anorexic actions and indicate that drugs targeting these downstream melanocortin pathways may prove to be effective and more selective anti-obesity treatments. 相似文献
995.
In natural habitats, bacteria spend most of their time in some form of growth arrest. Little is known about deleterious mutations in such stages, and consequently there is limited understanding of what evolutionary events occur. In a deleterious mutation accumulation experiment in prolonged stationary phase of Escherichia coli, about 0.03 slightly deleterious mutations were observed per genome per day. This is over an order of magnitude higher than extrapolations from fast-growing cells, but in line with inferences from observations in adaptive stationary phase mutation experiments. These findings may affect understanding of bacterial evolution and the emergence of bacterial pathogenicity. 相似文献
996.
Marion Navarri Camille Jégou Laurence Meslet-Cladière Benjamin Brillet Georges Barbier Ga?tan Burgaud Yannick Fleury 《Marine drugs》2016,14(3)
The evolving global threat of antimicrobial resistance requires a deep renewal of the antibiotic arsenal including the isolation and characterization of new drugs. Underexplored marine ecosystems may represent an untapped reservoir of novel bioactive molecules. Deep-sea fungi isolated from a record-depth sediment core of almost 2000 m below the seafloor were investigated for antimicrobial activities. This antimicrobial screening, using 16 microbial targets, revealed 33% of filamentous fungi synthesizing bioactive compounds with activities against pathogenic bacteria and fungi. Interestingly, occurrence of antimicrobial producing isolates was well correlated with the complexity of the habitat (in term of microbial richness), as higher antimicrobial activities were obtained at specific layers of the sediment core. It clearly highlights complex deep-sea habitats as chemical battlefields where synthesis of numerous bioactive compounds appears critical for microbial competition. The six most promising deep subseafloor fungal isolates were selected for the production and extraction of bioactive compounds. Depending on the fungal isolates, antimicrobial compounds were only biosynthesized in semi-liquid or solid-state conditions as no antimicrobial activities were ever detected using liquid fermentation. An exception was made for one fungal isolate, and the extraction procedure designed to extract amphipathic compounds was successful and highlighted the amphiphilic profile of the bioactive metabolites. 相似文献
997.
Carvalho Ddo C Brigagão MR dos Santos MH de Paula FB Giusti-Paiva A Azevedo L 《Plant foods for human nutrition (Dordrecht, Netherlands)》2011,66(2):114-121
Differentiation between organic and conventional coffee has increased due to the growing demand and high consumption of healthy
foods that contain compounds with antioxidant potential, which have been associated with the reduction of chronic diseases.
We used organic and conventional coffee in powder 4% (w/w) and infusions 5%, 10% and 20% (w/v) incorporated in a commercial
diet to test in vivo. The levels of chlorogenic acid, caffeine and trigonelline were determined by high performance liquid chromatography. The
body weight, weight gain, food consumption, aberrant foci crypt, mucin depleted foci, stress biomarkers protein carbonyl and
malondialdehyde, biochemical parameters and behavior of the rats were compared between the experimental and control groups
within a framework of colon carcinogenesis. The organic coffee showed higher levels of chlorogenic acid, caffeine and trigonelline
than conventional, however, this difference did not significantly affect behavior. The infusions had an antioxidant effect,
reducing the levels of malondialdehyde; however, the biochemical parameters of the serum were not altered, and there was neither
induction nor prevention of preneoplasic lesions. 相似文献
998.
Arminda Moreira de Carvalho Luana Ramos Passos Ribeiro Robélio Leandro Marchão Alexsandra Duarte de Oliveira Karina Pulrolnik Cícero Célio de Figueiredo 《Soil Use and Management》2022,38(1):940-952
In no-tillage systems (NTS), cover crops are recommended to increase the productivity of agricultural systems. Furthermore, a greater diversity of cover crops in NTS favours an increase in soil carbon (C) stocks. However, there are scarce published data on the relationship between the chemical composition of cover crops and the accumulation of labile and stable fractions of SOM. We evaluated the relationship between the chemical composition of cover crops and SOM fractions, C stocks and maize yield. Hemicellulose, cellulose and lignin contents were determined for Urochloa ruziziensis, Canavalia brasiliensis, Cajanus cajan and Sorghum bicolor, cultivated in the off-season of maize. Canavalia brasiliensis had high N (20.96 g kg−1) and hemicellulose (185.67 g kg−1) contents, lower lignin content (39.50 g kg−1) and high dry matter yield (3,251 kg ha−1). All these characteristics resulted in a better SOM quality. Urochloa ruziziensis, with higher hemicellulose and lower lignin contents, and low lignin/N ratio, was associated with accumulation of TOC (19.95 and 18.33 g kg−1 in 0- to 10-cm and 10- to 20-cm layers, respectively) and mineral-associated organic C (on average, 16.68 g kg−1) in the soil. Cover plants with N:lignin ratio lower than 2.0 are fundamental for soil C sequestration. In conclusion, it is recommended the adoption of Urochloa ruziziensis and Canavalia brasiliensis as cover plants improve maize production, soil organic matter quality and C sequestration in the Cerrado region. 相似文献
999.
Lustosa-Silva Jéssica Daniele Ferreira-Gomes Regina Lucia Martínez-Castillo Jaime Carvalho Leonardo Castelo Branco de Oliveira Leonardo Furtado Ortiz-García Matilde Margarita Sánchez-Sosa Alba Gabriela da Silva Geice Ribeiro Costa Marcones Ferreira Silva Verônica Brito Lopes Ângela Celis de Almeida 《Genetic Resources and Crop Evolution》2022,69(8):2819-2832
Genetic Resources and Crop Evolution - Lima bean (Phaseolus lunatus L.) is a crop that stands out for its economic and social importance throughout the world, including in Northeast Brazil.... 相似文献
1000.
Samara N. C. Vicentini Priscila S. Casado Giselle de Carvalho Silvino I. Moreira Adriano F. Dorigan Tatiane C. Silva Abimael G. Silva Adriano A. P. Custódio Ana Carolina S. Gomes João L. Nunes Maciel Nichola Hawkins Bruce A. McDonald Bart A. Fraaije Paulo C. Ceresini 《Plant pathology》2022,71(2):304-321
Wheat blast is one of the most important and devastating fungal diseases of wheat in South America, South-east Asia, and now in southern Africa. The disease can reduce grain yield by up to 70% and is best controlled using integrated disease management strategies. The difficulty in disease management is compounded by the lack of durable host resistance and the ineffectiveness of fungicide sprays. New succinate dehydrogenase inhibitor (SDHI) fungicides were recently introduced for the management of wheat diseases. Brazilian field populations of the wheat blast pathogen Pyricularia oryzae Triticum lineage (PoTl) sampled from different geographical regions in 2012 and 2018 were shown to be resistant to both QoI (strobilurin) and DMI (azole) fungicides. The main objective of the current study was to determine the SDHI baseline sensitivity in these populations. Moderate levels of SDHI resistance were detected in five out of the six field populations sampled in 2012 and in most of the strains isolated in 2018. No association was found between target site mutations in the sdhB, sdhC, and sdhD genes and the levels of SDHI resistance, indicating that a pre-existing resistance mechanism not associated with target site mutations is probably present in Brazilian wheat blast populations. 相似文献