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Kinga Michno David Knight Jorge M. Campussano Diana van de Hoef Gabrielle L. Boulianne 《PloS one》2009,4(9)
Much of our current understanding about neurodegenerative diseases can be attributed to the study of inherited forms of these disorders. For example, mutations in the presenilin 1 and 2 genes have been linked to early onset familial forms of Alzheimer''s disease (FAD). Using the Drosophila central nervous system as a model we have investigated the role of presenilin in one of the earliest cellular defects associated with Alzheimer''s disease, intracellular calcium deregulation. We show that expression of either wild type or FAD-mutant presenilin in Drosophila CNS neurons has no impact on resting calcium levels but does give rise to deficits in intracellular calcium stores. Furthermore, we show that a loss-of-function mutation in calmodulin, a key regulator of intracellular calcium, can suppress presenilin-induced deficits in calcium stores. Our data support a model whereby presenilin plays a role in regulating intracellular calcium stores and demonstrate that Drosophila can be used to study the link between presenilin and calcium deregulation. 相似文献
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A gene encoding the endogenous superantigen Mlsc, which deletes Tcrb-V3+ T cells in the NOD inbred mouse strain, was found to co-segregate with Mtv-3 on chromosome 11. This identifies a fourth gene encoding a deletion ligand for Tcrb-V3+ T cells and extends recently published observations in support of the hypothesis that a number of endogenous superantigens are the products of Mtv proviruses.
Address correspondence and offprint requests to : K. Tomonari. 相似文献
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We have identified and partially purified a growth inhibitor protein secreted by human diploid fibroblast cells. This protein is not secreted constitutively but only after induction with the double stranded hetero duplex polyriboinosinic:polyribocytidylic acid. The growth inhibitory activity has been purified 3,800-fold and has an estimated molecular mass of 12,000 daltons. The protein will inhibit the growth in culture of human diploid fibroblast cells, human cells derived from tumors, and mouse L cells. Although interferon-beta is secreted with the growth inhibitory protein, the partially purified growth inhibitory protein has no antiviral activity, and its activity is not neutralized by antibodies to interferon-alpha, interferon-beta, and interferon-gamma. We believe this growth inhibitory activity to reside in a newly defined protein and have named it fibroblast-derived growth inhibitor. 相似文献
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Carolyn M. Giles Beatrice Uring-Lambert Wolfgang Boksch Margot Braun Joelle Goetz Rainer Neumann Gottfried Mauff Georges Hauptmann 《Human genetics》1987,77(4):359-365
Summary The finding of two duplicated C4A haplotypes in a normal French family led to a detailed study of their C4 polymorphism. The father had an extremely rare A*6A*11, B* QO haplotype inherited by all of his children and the mother had the more common A*3A*2, B*QO haplotype. Two HLA identical daughters only have four C4A alleles. The father's A11 allotype expresses Ch: 1 (Chido) rather than Rg:1 (Rodgers) and represents a new Ch phenotype Ch: 1,-2,-3,-4,-5,-6. In order to clarify the genetic background in this unusual family, DNA studies of restriction fragment length polymorphisms (RFLPs) were undertake. The father's rare haplotype, which expresses two C4A allotypes, results from a long and a short C4 gene normally associated with the A*6, B*1 that also exhibits the BglII RFLP. As it travels in an extended MHC haplotype HLA A2, B57 (17), C2*C, BF*S, DR7 that is most frequently associated with A*6, B*1, we postulate that the short C4B has been converted in the chain region to a C4A gene which produces a C4A protein. This report of a short C4A gene is the first example in the complex polymorphism of C4. 相似文献
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Simple, rapid method for direct isolation of nucleic acids from aquatic environments 总被引:34,自引:0,他引:34
C C Somerville I T Knight W L Straube R R Colwell 《Applied and environmental microbiology》1989,55(3):548-554
Direct isolation of nucleic acids from the environment may be useful in several respects, including the estimation of total biomass, detection of specific organisms and genes, estimations of species diversity, and cloning applications. We have developed a method that facilitates the concentration of microorganisms from aquatic samples and the extraction of their nucleic acids. Natural water samples of 350 to greater than 1,000 ml are concentrated on a single cylindrical filter membrane (type SVGS01015; Millipore Corp., Bedford, Mass.), and cell lysis and proteolysis are carried out within the filter housing. Crude, high-molecular-weight nucleic acid solutions are then drawn off the filter. These solutions can be immediately analyzed, concentrated, or purified, depending on the intended application. The method is simple, rapid, and economical and provides high-molecular-weight chromosomal DNA, plasmid DNA, and speciated RNAs which comigrate with 5S, 16S, and 23S rRNAs. The methods presented here should prove useful in studying both the ecology and the phylogeny of microbes that resist classical culture methods. 相似文献