排序方式: 共有59条查询结果,搜索用时 15 毫秒
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Gout AM;ADPKD Gene Variant Consortium Ravine D Harris PC Rossetti S Peters D Breuning M Henske EP Koizumi A Inoue S Shimizu Y Thongnoppakhun W Yenchitsomanus PT Deltas C Sandford R Torra R Turco AE Jeffery S Fontes M Somlo S Furu LM Smulders YM Mercier B Ferec C Burtey S Pei Y Kalaydjieva L Bogdanova N McCluskey M Geon LJ Wouters CH Reiterova J Stekrová J San Millan JL Aguiari G Del Senno L 《Nature genetics》2007,39(4):427-428
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Gardner MJ Shallom SJ Carlton JM Salzberg SL Nene V Shoaibi A Ciecko A Lynn J Rizzo M Weaver B Jarrahi B Brenner M Parvizi B Tallon L Moazzez A Granger D Fujii C Hansen C Pederson J Feldblyum T Peterson J Suh B Angiuoli S Pertea M Allen J Selengut J White O Cummings LM Smith HO Adams MD Venter JC Carucci DJ Hoffman SL Fraser CM 《Nature》2002,419(6906):531-534
The mosquito-borne malaria parasite Plasmodium falciparum kills an estimated 0.7-2.7 million people every year, primarily children in sub-Saharan Africa. Without effective interventions, a variety of factors-including the spread of parasites resistant to antimalarial drugs and the increasing insecticide resistance of mosquitoes-may cause the number of malaria cases to double over the next two decades. To stimulate basic research and facilitate the development of new drugs and vaccines, the genome of Plasmodium falciparum clone 3D7 has been sequenced using a chromosome-by-chromosome shotgun strategy. We report here the nucleotide sequences of chromosomes 10, 11 and 14, and a re-analysis of the chromosome 2 sequence. These chromosomes represent about 35% of the 23-megabase P. falciparum genome. 相似文献
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The diatom flora of selected sites in the Animas River Watershed, San Juan County, Colorado, was studied. Eighty diatom taxa were identified from 10 sites: 8 sites on the Animas River and 1 site each on the Cement and Cascade tributaries. The sample diatom abundance was dominated by Achnanthidium minutissimum , Encyonema silesiacum , Aulacoseira distans , Hannaea arcus , and Diatoma mesodon . The presence of teratologic specimens of Fragilaria and Achnanthidium in the samples indicated the possibility of metals contamination. Diatom diversity was low and Lange-Bertalot pollution index scores indicated little organic pollution evidenced from diatom composition. There was evidence that diatom composition at the sites was differentially affected by pH and possibly by the concentrations of Zn alone or in combination with Cd, Cu, and Fe. 相似文献
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The influenza A viral heterotrimeric polymerase complex (PA, PB1, PB2) is known to be involved in many aspects of viral replication and to interact with host factors, thereby having a role in host specificity. The polymerase protein sequences from the 1918 human influenza virus differ from avian consensus sequences at only a small number of amino acids, consistent with the hypothesis that they were derived from an avian source shortly before the pandemic. However, when compared to avian sequences, the nucleotide sequences of the 1918 polymerase genes have more synonymous differences than expected, suggesting evolutionary distance from known avian strains. Here we present sequence and phylogenetic analyses of the complete genome of the 1918 influenza virus, and propose that the 1918 virus was not a reassortant virus (like those of the 1957 and 1968 pandemics), but more likely an entirely avian-like virus that adapted to humans. These data support prior phylogenetic studies suggesting that the 1918 virus was derived from an avian source. A total of ten amino acid changes in the polymerase proteins consistently differentiate the 1918 and subsequent human influenza virus sequences from avian virus sequences. Notably, a number of the same changes have been found in recently circulating, highly pathogenic H5N1 viruses that have caused illness and death in humans and are feared to be the precursors of a new influenza pandemic. The sequence changes identified here may be important in the adaptation of influenza viruses to humans. 相似文献
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Hao HX Xie Y Zhang Y Charlat O Oster E Avello M Lei H Mickanin C Liu D Ruffner H Mao X Ma Q Zamponi R Bouwmeester T Finan PM Kirschner MW Porter JA Serluca FC Cong F 《Nature》2012,485(7397):195-200
R-spondin proteins strongly potentiate Wnt signalling and function as stem-cell growth factors. Despite the biological and therapeutic significance, the molecular mechanism of R-spondin action remains unclear. Here we show that the cell-surface transmembrane E3 ubiquitin ligase zinc and ring finger 3 (ZNRF3) and its homologue ring finger 43 (RNF43) are negative feedback regulators of Wnt signalling. ZNRF3 is associated with the Wnt receptor complex, and inhibits Wnt signalling by promoting the turnover of frizzled and LRP6. Inhibition of ZNRF3 enhances Wnt/β-catenin signalling and disrupts Wnt/planar cell polarity signalling in vivo. Notably, R-spondin mimics ZNRF3 inhibition by increasing the membrane level of Wnt receptors. Mechanistically, R-spondin interacts with the extracellular domain of ZNRF3 and induces the association between ZNRF3 and LGR4, which results in membrane clearance of ZNRF3. These data suggest that R-spondin enhances Wnt signalling by inhibiting ZNRF3. Our study provides new mechanistic insights into the regulation of Wnt receptor turnover, and reveals ZNRF3 as a tractable target for therapeutic exploration. 相似文献
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Mutations in PTPN11, encoding the protein tyrosine phosphatase SHP-2, cause Noonan syndrome. 总被引:23,自引:0,他引:23
M Tartaglia E L Mehler R Goldberg G Zampino H G Brunner H Kremer I van der Burgt A H Crosby A Ion S Jeffery K Kalidas M A Patton R S Kucherlapati B D Gelb 《Nature genetics》2001,29(4):465-468
Noonan syndrome (MIM 163950) is an autosomal dominant disorder characterized by dysmorphic facial features, proportionate short stature and heart disease (most commonly pulmonic stenosis and hypertrophic cardiomyopathy). Webbed neck, chest deformity, cryptorchidism, mental retardation and bleeding diatheses also are frequently associated with this disease. This syndrome is relatively common, with an estimated incidence of 1 in 1,000-2,500 live births. It has been mapped to a 5-cM region (NS1) [corrected] on chromosome 12q24.1, and genetic heterogeneity has also been documented. Here we show that missense mutations in PTPN11 (MIM 176876)-a gene encoding the nonreceptor protein tyrosine phosphatase SHP-2, which contains two Src homology 2 (SH2) domains-cause Noonan syndrome and account for more than 50% of the cases that we examined. All PTPN11 missense mutations cluster in interacting portions of the amino N-SH2 domain and the phosphotyrosine phosphatase domains, which are involved in switching the protein between its inactive and active conformations. An energetics-based structural analysis of two N-SH2 mutants indicates that in these mutants there may be a significant shift of the equilibrium favoring the active conformation. This implies that they are gain-of-function changes and that the pathogenesis of Noonan syndrome arises from excessive SHP-2 activity. 相似文献
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Alterations in the composition and function of the gut microbiome have been implicated in a range of conditions and diseases. Culture-dependent and culture-independent studies both showed that older people harbour a gut microbiome that differs in composition from that of younger adults. Detailed analyses have identified discrete microbiota subtypes that characterize intermediates between a high diversity microbiota found in healthy community-dwelling subjects and a low diversity microbiota typical for elderly living in long-term residential care. There are also alterations in the microbiome composition associated with biological age, independent of health status. Even after adjusting for confounding factors such as age and medication, trends in microbiota composition correlate with gradients in clinical metadata particularly frailty and inflammatory status. There are few known mechanisms by which these associations might be causative rather than consequential, and this is a subject of intensive research. The strongest candidate effectors are microbial metabolites that could impact host energy balance, act as signalling molecules to modulate host metabolism or inflammation, and potentially also impact on the gut–brain axis. 相似文献
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New invasions, better field data, and novel spatial-modeling techniques often drive the need to revisit previous maps and models of invasive species. Such is the case with the at least 10 species of Tamarix, which are invading riparian systems in the western United States and expanding their range throughout North America. In 2006, we developed a National Tamarisk Map by using a compilation of presence and absence locations with remotely sensed data and statistical modeling techniques. Since the publication of that work, our database of Tamarix distributions has grown significantly. Using the updated database of species occurrence, new predictor variables, and the maximum entropy (Maxent) model, we have revised our potential Tamarix distribution map for the western United States. Distance-to-water was the strongest predictor in the model (58.1%), while mean temperature of the warmest quarter was the second best predictor (18.4%). Model validation, averaged from 25 model iterations, indicated that our analysis had strong predictive performance (AUC = 0.93) and that the extent of Tamarix distributions is much greater than previously thought. The southwestern United States had the greatest suitable habitat, and this result differed from the 2006 model. Our work highlights the utility of iterative modeling for invasive species habitat modeling as new information becomes available. A menudo las nuevas invasiones, mejores datos de campo y técnicas novedosas de modelado espacial impulsan la actualización de los mapas y de los modelos existentes de especies invasoras. Este es el caso de al menos 10 especies de Tamarix, las cuales están invadiendo los sistemas ribereños en el oeste de los EE.UU. y extendiendo su distribución por toda Norteamérica. En 2006, desarrollamos un mapa nacional del tamarisco (National Tamarisk Map) utilizando una compilación de sitios de presencia y ausencia con datos de sensores remotos y técnicas de modelación estadística. Desde la publicación de este trabajo, nuestra base de datos sobre la distribución de Tamarix ha crecido considerablemente. Utilizando la base de datos actualizada de presencia de especies, nuevas variables predictoras y el modelo de máxima entropía (Maxent), hemos modificado nuestro mapa de la distribución potencial de Tamarix para el oeste de los EE.UU. El predictor más fuerte en el modelo fue la distancia al agua (58.1%), y la temperatura promedio del trimestre más cálido fue el segundo (18.4%). La validación de modelo, calculada como el promedio de 25 iteraciones del modelo, indicó que nuestro análisis tuvo una alta capacidad predictiva (ABC = 0.93), y que la distribución de Tamarix es mucho más extensa de lo que se pensaba. El suroeste de los EE.UU. tuvo la mayor cantidad de hábitat adecuado para la especie, y este resultado difirió del modelo de 2006. Nuestro trabajo enfatiza la utilidad del modelado iterativo para modelar el hábitat de las especies invasoras a medida que se disponga de nueva información. 相似文献