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排序方式: 共有518条查询结果,搜索用时 15 毫秒
111.
Gissen P Johnson CA Morgan NV Stapelbroek JM Forshew T Cooper WN McKiernan PJ Klomp LW Morris AA Wraith JE McClean P Lynch SA Thompson RJ Lo B Quarrell OW Di Rocco M Trembath RC Mandel H Wali S Karet FE Knisely AS Houwen RH Kelly DA Maher ER 《Nature genetics》2004,36(4):400-404
ARC syndrome (OMIM 208085) is an autosomal recessive multisystem disorder characterized by neurogenic arthrogryposis multiplex congenita, renal tubular dysfunction and neonatal cholestasis with bile duct hypoplasia and low gamma glutamyl transpeptidase (gGT) activity. Platelet dysfunction is common. Affected infants do not thrive and usually die in the first year of life. To elucidate the molecular basis of ARC, we mapped the disease to a 7-cM interval on 15q26.1 and then identified germline mutations in the gene VPS33B in 14 kindreds with ARC. VPS33B encodes a homolog of the class C yeast vacuolar protein sorting gene, Vps33, that contains a Sec1-like domain important in the regulation of vesicle-to-target SNARE complex formation and subsequent membrane fusion. 相似文献
112.
Boyd PW Law CS Wong CS Nojiri Y Tsuda A Levasseur M Takeda S Rivkin R Harrison PJ Strzepek R Gower J McKay M Abraham E Arychuk M Barwell-Clarke J Crawford W Crawford D Hale M Harada K Johnson K Kiyosawa H Kudo I Marchetti A Miller W Needoba J Nishioka J Ogawa H Page J Robert M Saito H Sastri A Sherry N Soutar T Sutherland N Taira Y Whitney F Wong SK Yoshimura T 《Nature》2004,428(6982):549-553
Iron supply has a key role in stimulating phytoplankton blooms in high-nitrate low-chlorophyll oceanic waters. However, the fate of the carbon fixed by these blooms, and how efficiently it is exported into the ocean's interior, remains largely unknown. Here we report on the decline and fate of an iron-stimulated diatom bloom in the Gulf of Alaska. The bloom terminated on day 18, following the depletion of iron and then silicic acid, after which mixed-layer particulate organic carbon (POC) concentrations declined over six days. Increased particulate silica export via sinking diatoms was recorded in sediment traps at depths between 50 and 125 m from day 21, yet increased POC export was not evident until day 24. Only a small proportion of the mixed-layer POC was intercepted by the traps, with more than half of the mixed-layer POC deficit attributable to bacterial remineralization and mesozooplankton grazing. The depletion of silicic acid and the inefficient transfer of iron-increased POC below the permanent thermocline have major implications both for the biogeochemical interpretation of times of greater iron supply in the geological past, and also for proposed geo-engineering schemes to increase oceanic carbon sequestration. 相似文献
113.
Dyall SD Yan W Delgadillo-Correa MG Lunceford A Loo JA Clarke CF Johnson PJ 《Nature》2004,431(7012):1103-1107
Trichomonas vaginalis is a unicellular microaerophilic eukaryote that lacks mitochondria yet contains an alternative organelle, the hydrogenosome, involved in pyruvate metabolism. Pathways between the two organelles differ substantially: in hydrogenosomes, pyruvate oxidation is catalysed by pyruvate:ferredoxin oxidoreductase (PFOR), with electrons donated to an [Fe]-hydrogenase which produces hydrogen. ATP is generated exclusively by substrate-level phosphorylation in hydrogenosomes, as opposed to oxidative phosphorylation in mitochondria. PFOR and hydrogenase are found in eubacteria and amitochondriate eukaryotes, but not in typical mitochondria. Analyses of mitochondrial genomes indicate that mitochondria have a single endosymbiotic origin from an alpha-proteobacterial-type progenitor. The absence of a genome in trichomonad hydrogenosomes precludes such comparisons, leaving the endosymbiotic history of this organelle unclear. Although phylogenetic reconstructions of a few proteins indicate that trichomonad hydrogenosomes share a common origin with mitochondria, others do not. Here we describe a novel NADH dehydrogenase module of respiratory complex I that is coupled to the central hydrogenosomal fermentative pathway to form a hydrogenosomal oxidoreductase complex that seems to function independently of quinones. Phylogenetic analyses of hydrogenosomal complex I-like proteins Ndh51 and Ndh24 reveal that neither has a common origin with mitochondrial homologues. These studies argue against a vertical origin of trichomonad hydrogenosomes from the proto-mitochondrial endosymbiont. 相似文献
114.
A basic doctrine of reproductive biology is that most mammalian females lose the capacity for germ-cell renewal during fetal life, such that a fixed reserve of germ cells (oocytes) enclosed within follicles is endowed at birth. Here we show that juvenile and adult mouse ovaries possess mitotically active germ cells that, based on rates of oocyte degeneration (atresia) and clearance, are needed to continuously replenish the follicle pool. Consistent with this, treatment of prepubertal female mice with the mitotic germ-cell toxicant busulphan eliminates the primordial follicle reserve by early adulthood without inducing atresia. Furthermore, we demonstrate cells expressing the meiotic entry marker synaptonemal complex protein 3 in juvenile and adult mouse ovaries. Wild-type ovaries grafted into transgenic female mice with ubiquitous expression of green fluorescent protein (GFP) become infiltrated with GFP-positive germ cells that form follicles. Collectively, these data establish the existence of proliferative germ cells that sustain oocyte and follicle production in the postnatal mammalian ovary. 相似文献
115.
116.
Association of cadherin 23 with polygenic inheritance and genetic modification of sensorineural hearing loss 总被引:20,自引:0,他引:20
Age-related hearing loss (AHL) in common inbred mouse strains is a genetically complex quantitative trait. We found a synonymous single-nucleotide polymorphism in exon 7 of Cdh23 that shows significant association with AHL and the deafness modifier mdfw (modifer of deafwaddler). The hypomorphic Cdh23(753A) allele causes in-frame skipping of exon 7. Altered adhesion or reduced stability of CDH23 may confer susceptibility to AHL. Homozygosity at Cdh23(753A) or in combination with heterogeneous secondary factors is a primary determinant of AHL in mice. 相似文献
117.
Aebischer NJ Baker SE Johnson PJ Macdonald DW Reynolds JC 《Nature》2003,423(6938):400; discussion 400
118.
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120.
Genetic determinants of ulcerative colitis include the ECM1 locus and five loci implicated in Crohn's disease 总被引:1,自引:0,他引:1
Fisher SA Tremelling M Anderson CA Gwilliam R Bumpstead S Prescott NJ Nimmo ER Massey D Berzuini C Johnson C Barrett JC Cummings FR Drummond H Lees CW Onnie CM Hanson CE Blaszczyk K Inouye M Ewels P Ravindrarajah R Keniry A Hunt S Carter M Watkins N Ouwehand W Lewis CM Cardon L;Wellcome Trust Case Control Consortium Lobo A Forbes A Sanderson J Jewell DP Mansfield JC Deloukas P Mathew CG Parkes M Satsangi J 《Nature genetics》2008,40(6):710-712
We report results of a nonsynonymous SNP scan for ulcerative colitis and identify a previously unknown susceptibility locus at ECM1. We also show that several risk loci are common to ulcerative colitis and Crohn's disease (IL23R, IL12B, HLA, NKX2-3 and MST1), whereas autophagy genes ATG16L1 and IRGM, along with NOD2 (also known as CARD15), are specific for Crohn's disease. These data provide the first detailed illustration of the genetic relationship between these common inflammatory bowel diseases. 相似文献