排序方式: 共有31条查询结果,搜索用时 187 毫秒
11.
Fabian AC Johnstone RM Sanders JS Conselice CJ Crawford CS Gallagher JS Zweibel E 《Nature》2008,454(7207):968-970
The giant elliptical galaxy NGC 1275, at the centre of the Perseus cluster, is surrounded by a well-known giant nebulosity of emission-line filaments, which are plausibly in excess of 10(8) years old. The filaments are dragged out from the centre of the galaxy by radio-emitting 'bubbles' rising buoyantly in the hot intracluster gas, before later falling back. They act as markers of the feedback process by which energy is transferred from the central massive black hole to the surrounding gas. The mechanism by which the filaments are stabilized against tidal shear and dissipation into the surrounding extremely hot (4 x 10(7) K) gas has been unclear. Here we report observations that resolve thread-like structures in the filaments. Some threads extend over 6 kpc, yet are only 70 pc wide. We conclude that magnetic fields in the threads, in pressure balance with the surrounding gas, stabilize the filaments, so allowing a large mass of cold gas to accumulate and delay star formation. 相似文献
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Mechanism and site of vitamin B 12 absorption in suckling rats 总被引:1,自引:0,他引:1
N D Gallagher 《Nature》1969,222(5196):877-878
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Molecular basis of autosomal-dominant polycystic kidney disease 总被引:5,自引:0,他引:5
Gallagher AR Hidaka S Gretz N Witzgall R 《Cellular and molecular life sciences : CMLS》2002,59(4):682-693
Autosomal-dominant polycystic kidney disease (ADPKD) is one of the most common monogenetic diseases in humans. The discovery
that mutations in the PKD1 and PKD2 genes are responsible for ADPKD has sparked extensive research efforts into the physiological and pathogenetic role of polycystin-1
and polycystin-2, the proteins encoded by these two genes. While polycystin-1 may mediate the contact among cells or between
cells and the extracellular matrix, a lot of evidence suggests that polycystin-2 represents an endoplasmic reticulum-bound
cation channel. Cyst development has been compared to the growth of benign tumors and this view is highlighted by the model
that a somatic mutation in addition to the germline mutation is responsible for cystogenesis (two-hit model of cyst formation).
Since in vitro polycystin-1 and polycystin-2 interact through their COOH termini, the two proteins possibly act in a common
pathway, which controls the width of renal tubules. The loss of one protein may lead to a disruption of this pathway and to
the uncontrolled expansion of tubules. Our increasing knowledge of the molecular events in ADPKD has also started to be useful
in designing novel diagnostic and therapeutic strategies.
Received 12 September 2001; received after revision 7 November 2001; accepted 7 November 2001 相似文献
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Davis EE Zhang Q Liu Q Diplas BH Davey LM Hartley J Stoetzel C Szymanska K Ramaswami G Logan CV Muzny DM Young AC Wheeler DA Cruz P Morgan M Lewis LR Cherukuri P Maskeri B Hansen NF Mullikin JC Blakesley RW Bouffard GG;NISC Comparative Sequencing Program Gyapay G Rieger S Tönshoff B Kern I Soliman NA Neuhaus TJ Swoboda KJ Kayserili H Gallagher TE Lewis RA Bergmann C Otto EA Saunier S Scambler PJ Beales PL Gleeson JG Maher ER Attié-Bitach T Dollfus H Johnson CA Green ED Gibbs RA Hildebrandt F 《Nature genetics》2011,43(3):189-196
Ciliary dysfunction leads to a broad range of overlapping phenotypes, collectively termed ciliopathies. This grouping is underscored by genetic overlap, where causal genes can also contribute modifier alleles to clinically distinct disorders. Here we show that mutations in TTC21B, which encodes the retrograde intraflagellar transport protein IFT139, cause both isolated nephronophthisis and syndromic Jeune asphyxiating thoracic dystrophy. Moreover, although resequencing of TTC21B in a large, clinically diverse ciliopathy cohort and matched controls showed a similar frequency of rare changes, in vivo and in vitro evaluations showed a significant enrichment of pathogenic alleles in cases (P < 0.003), suggesting that TTC21B contributes pathogenic alleles to ~5% of ciliopathy cases. Our data illustrate how genetic lesions can be both causally associated with diverse ciliopathies and interact in trans with other disease-causing genes and highlight how saturated resequencing followed by functional analysis of all variants informs the genetic architecture of inherited disorders. 相似文献
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Lesné S Koh MT Kotilinek L Kayed R Glabe CG Yang A Gallagher M Ashe KH 《Nature》2006,440(7082):352-357
Memory function often declines with age, and is believed to deteriorate initially because of changes in synaptic function rather than loss of neurons. Some individuals then go on to develop Alzheimer's disease with neurodegeneration. Here we use Tg2576 mice, which express a human amyloid-beta precursor protein (APP) variant linked to Alzheimer's disease, to investigate the cause of memory decline in the absence of neurodegeneration or amyloid-beta protein amyloidosis. Young Tg2576 mice (< 6 months old) have normal memory and lack neuropathology, middle-aged mice (6-14 months old) develop memory deficits without neuronal loss, and old mice (> 14 months old) form abundant neuritic plaques containing amyloid-beta (refs 3-6). We found that memory deficits in middle-aged Tg2576 mice are caused by the extracellular accumulation of a 56-kDa soluble amyloid-beta assembly, which we term Abeta*56 (Abeta star 56). Abeta*56 purified from the brains of impaired Tg2576 mice disrupts memory when administered to young rats. We propose that Abeta*56 impairs memory independently of plaques or neuronal loss, and may contribute to cognitive deficits associated with Alzheimer's disease. 相似文献
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Dragon F Gallagher JE Compagnone-Post PA Mitchell BM Porwancher KA Wehner KA Wormsley S Settlage RE Shabanowitz J Osheim Y Beyer AL Hunt DF Baserga SJ 《Nature》2002,417(6892):967-970
Although the U3 small nucleolar RNA (snoRNA), a member of the box C/D class of snoRNAs, was identified with the spliceosomal small nuclear RNAs (snRNAs) over 30 years ago, its function and its associated protein components have remained more elusive. The U3 snoRNA is ubiquitous in eukaryotes and is required for nucleolar processing of pre-18S ribosomal RNA in all organisms where it has been tested. Biochemical and genetic analyses suggest that U3 pre-rRNA base-pairing interactions mediate endonucleolytic pre-rRNA cleavages. Here we have purified a large ribonucleoprotein (RNP) complex from Saccharomyces cerevisiae that contains the U3 snoRNA and 28 proteins. Seventeen new proteins (Utp1 17) and Rrp5 were present, as were ten known components. The Utp proteins are nucleolar and specifically associated with the U3 snoRNA. Depletion of the Utp proteins impedes production of the 18S rRNA, indicating that they are part of the active pre-rRNA processing complex. On the basis of its large size (80S; calculated relative molecular mass of at least 2,200,000) and function, this complex may correspond to the terminal knobs present at the 5' ends of nascent pre-rRNAs. We have termed this large RNP the small subunit (SSU) processome. 相似文献
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Summary Tremor dose-response curves were determined for mice dosed with the ryegrass neurotoxin lolitrem B, and the tremorgenic mycotoxin aflatrem. A family of characteristic curves was revealed for each tremorgen, with lolitrem B eliciting a sustained tremor response persisting for over 24 h. 相似文献
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