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81.
We describe mutations in the PML nuclear body protein Sp110 in the syndrome veno-occlusive disease with immunodeficiency, an autosomal recessive disorder of severe hypogammaglobulinemia, combined T and B cell immunodeficiency, absent lymph node germinal centers, absent tissue plasma cells and hepatic veno-occlusive disease. This is the first report of the involvement of a nuclear body protein in a human primary immunodeficiency and of high-penetrance genetic mutations in hepatic veno-occlusive disease.  相似文献   
82.
Cerebello-oculo-renal syndrome (CORS), also called Joubert syndrome type B, and Meckel (MKS) syndrome belong to the group of developmental autosomal recessive disorders that are associated with primary cilium dysfunction. Using SNP mapping, we identified missense and truncating mutations in RPGRIP1L (KIAA1005) in both CORS and MKS, and we show that inactivation of the mouse ortholog Rpgrip1l (Ftm) recapitulates the cerebral, renal and hepatic defects of CORS and MKS. In addition, we show that RPGRIP1L colocalizes at the basal body and centrosomes with the protein products of both NPHP6 and NPHP4, known genes associated with MKS, CORS and nephronophthisis (a related renal disorder and ciliopathy). In addition, the RPGRIP1L missense mutations found in CORS individuals diminishes the interaction between RPGRIP1L and nephrocystin-4. Our findings show that mutations in RPGRIP1L can cause the multiorgan phenotypic abnormalities found in CORS or MKS, which therefore represent a continuum of the same underlying disorder.  相似文献   
83.
Limb-girdle muscular dystrophy type 1D (LGMD1D) was linked to chromosome 7q36 over a decade ago, but its genetic cause has remained elusive. Here we studied nine LGMD-affected families from Finland, the United States and Italy and identified four dominant missense mutations leading to p.Phe93Leu or p.Phe89Ile changes in the ubiquitously expressed co-chaperone DNAJB6. Functional testing in vivo showed that the mutations have a dominant toxic effect mediated specifically by the cytoplasmic isoform of DNAJB6. In vitro studies demonstrated that the mutations increase the half-life of DNAJB6, extending this effect to the wild-type protein, and reduce its protective anti-aggregation effect. Further, we show that DNAJB6 interacts with members of the CASA complex, including the myofibrillar myopathy-causing protein BAG3. Our data identify the genetic cause of LGMD1D, suggest that its pathogenesis is mediated by defective chaperone function and highlight how mutations in a ubiquitously expressed gene can exert effects in a tissue-, isoform- and cellular compartment-specific manner.  相似文献   
84.
Although thoracic aortic aneurysms and dissections (TAAD) can be inherited as a single-gene disorder, the genetic predisposition in the majority of affected people is poorly understood. In a multistage genome-wide association study (GWAS), we compared 765 individuals who had sporadic TAAD (STAAD) with 874 controls and identified common SNPs at a 15q21.1 locus that were associated with STAAD, with odds ratios of 1.6-1.8 that achieved genome-wide significance. We followed up 107 SNPs associated with STAAD with P < 1 × 10(-5) in the region, in two separate STAAD cohorts. The associated SNPs fall into a large region of linkage disequilibrium encompassing FBN1, which encodes fibrillin-1. FBN1 mutations cause Marfan syndrome, whose major cardiovascular complication is TAAD. This study shows that common genetic variants at 15q21.1 that probably act via FBN1 are associated with STAAD, suggesting a common pathogenesis of aortic disease in Marfan syndrome and STAAD.  相似文献   
85.
Calcium is known to play an essential part in the regulation of insulin secretion in the pancreatic beta cell. Calcium influx/efflux studies indicate that glucose promotes an accumulation of calcium by the beta cell. However, interpretation of such data is particularly difficult due to the complex compartmentalization of calcium within the cell. Although indirect evidence using chlorotetracycline suggests that control of calcium homeostasis at the plasma membrane may be central to insulin secretion, the mechanism by which secretagogues influence the handling of calcium remains unknown. Despite its continuous diffusive entry, intracellular calcium is maintained in the submicromolar range by energy-dependent mechanisms. One such process which has been well characterized in erythrocytes is a plasma membrane calcium extrusion pump whose enzymatic basis is a high affinity (Ca+2 + Mg+2)ATPase. A similar mechanism regulated by insulin has recently been identified in adipocyte plasma membranes. We report here the presence of a high affinity (Ca+2 + Mg+2)ATPase and ATP-dependent calmodulin-stimulated calcium transport system in rat pancreatic islet cell plasma membranes.  相似文献   
86.
非线性控制系统半实物仿真技术研究   总被引:2,自引:1,他引:1  
设计一非线形控制半实物仿真系统对非线型控制算法进行验证,并给出控制推力所需总冲的数学模型,分析了此非线形控制半实物仿真系统的误差,文中还通过型号仿真试验所得到的试验结果对非线形控制系统的设计进行了正确性验证,而且在试验过程中完善了控制系统的设计,同时也验证了该类仿真系统的正确性及仿真系统误差分析的正确性,该半实物仿真系统的建立对同类非线形控制半实物仿真系统的建立具有一定一的借鉴作用。  相似文献   
87.
Arabidopsis thaliana has emerged as a model system for studies of plant genetics and development, and its genome has been targeted for sequencing by an international consortium (the Arabidopsis Genome Initiative; http://genome-www. stanford.edu/Arabidopsis/agi.html). To support the genome-sequencing effort, we fingerprinted more than 20,000 BACs (ref. 2) from two high-quality publicly available libraries, generating an estimated 17-fold redundant coverage of the genome, and used the fingerprints to nucleate assembly of the data by computer. Subsequent manual revision of the assemblies resulted in the incorporation of 19,661 fingerprinted BACs into 169 ordered sets of overlapping clones ('contigs'), each containing at least 3 clones. These contigs are ideal for parallel selection of BACs for large-scale sequencing and have supported the generation of more than 5.8 Mb of finished genome sequence submitted to GenBank; analysis of the sequence has confirmed the integrity of contigs constructed using this fingerprint data. Placement of contigs onto chromosomes can now be performed, and is being pursued by groups involved in both sequencing and positional cloning studies. To our knowledge, these data provide the first example of whole-genome random BAC fingerprint analysis of a eucaryote, and have provided a model essential to efforts aimed at generating similar databases of fingerprint contigs to support sequencing of other complex genomes, including that of human.  相似文献   
88.
TSK动态网络及其在非线性动态系统中的应用   总被引:1,自引:1,他引:1  
徐春梅  尔联洁 《系统仿真学报》2006,18(8):2358-2361,2365
针对非线性动态系统特点,提出了一种新型的基于TSK模糊模型的动态回归模糊神经网DRFNN(Dynamic recurrent fuzzy neural networks),并给出了网络参教的迭代算法和基于李亚普诺夫稳定理论的收敛性证明。该动态回归网络由静态网络和内反馈动态回归网络组成,在结构上更好的拟合了非线性动态系统特点,应用于非线性动态系统的辨识和控制的试验结果也说明该动态回归模糊神经网络对解决非线性动态系统辨识和控制问题的有效性。  相似文献   
89.
针对三维目标(3D object)检索问题,提出了一种基于混合描述符及多支持向量机融合相关反馈学习的3D目标检索方法。在分析现行3D模型检索方法的基础上,提出了混合描述符HD及相关反馈学习的总体思路。讨论了HD框架构建,即在光场图像阵列自适应聚类基础上,分别实现HD各个子描述符。讨论了基于多支持向量机的融合分类学习机制,并将其用于3D目标检索反馈学习环节,对HD检索性能及相关反馈学习分类进行了实验分析,结果表明所提出的方法是有效的。  相似文献   
90.
We have sequenced and annotated the genome of fission yeast (Schizosaccharomyces pombe), which contains the smallest number of protein-coding genes yet recorded for a eukaryote: 4,824. The centromeres are between 35 and 110 kilobases (kb) and contain related repeats including a highly conserved 1.8-kb element. Regions upstream of genes are longer than in budding yeast (Saccharomyces cerevisiae), possibly reflecting more-extended control regions. Some 43% of the genes contain introns, of which there are 4,730. Fifty genes have significant similarity with human disease genes; half of these are cancer related. We identify highly conserved genes important for eukaryotic cell organization including those required for the cytoskeleton, compartmentation, cell-cycle control, proteolysis, protein phosphorylation and RNA splicing. These genes may have originated with the appearance of eukaryotic life. Few similarly conserved genes that are important for multicellular organization were identified, suggesting that the transition from prokaryotes to eukaryotes required more new genes than did the transition from unicellular to multicellular organization.  相似文献   
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