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991.
Background
The ability to predict antibody binding sites (aka antigenic determinants or B-cell epitopes) for a given protein is a precursor to new vaccine design and diagnostics. Among the various methods of B-cell epitope identification X-ray crystallography is one of the most reliable methods. Using these experimental data computational methods exist for B-cell epitope prediction. As the number of structures of antibody-protein complexes grows, further interest in prediction methods using 3D structure is anticipated. This work aims to establish a benchmark for 3D structure-based epitope prediction methods. 相似文献992.
A collection of fossils sampled during the 1898–1902 expedition of theFram to the Canadian Arctic Islands includes abundant bryozoans from the Lower Permian (Artinskian) Great Bear Cape Formation
of Ellesmere Island. From this material a new genus with one new species —Nansenopora peculiaris n. gen., n. sp. — as well as three new species —Streblotrypella arctica n. sp.,Phragmophera patricki n. sp. andKallodictyon spinatum n. sp. — are described. Furthermore, the speciesUlrichotrypa ramulosa
Bassler, 1929 is reported for the first time from the Lower Permian of the Arctic region. 相似文献
993.
Background
The trithorax group (trxG) genes absent, small or homeotic discs 1 (ash1) and 2 (ash2) were isolated in a screen for mutants with abnormal imaginal discs. Mutations in either gene cause homeotic transformations but Hox genes are not their only targets. Although analysis of double mutants revealed that ash2 and ash1 mutations enhance each other's phenotypes, suggesting they are functionally related, it was shown that these proteins are subunits of distinct complexes. 相似文献994.
995.
Gajanan T Behere Wee Tek Tay Derek A Russell David G Heckel Belinda R Appleton Keshav R Kranthi Philip Batterham 《BMC evolutionary biology》2007,7(1):117
Background
Helicoverpa armigera and H. zea are amongst the most significant polyphagous pest lepidopteran species in the Old and New Worlds respectively. Separation of H. armigera and H. zea is difficult and is usually only achieved through morphological differences in the genitalia. They are capable of interbreeding to produce fertile offspring. The single species status of H. armigera has been doubted, due to its wide distribution and plant host range across the Old World. This study explores the global genetic diversity of H. armigera and its evolutionary relationship to H zea. 相似文献996.
The small RNA repertoire of Dictyostelium discoideum and its regulation by components of the RNAi pathway 下载免费PDF全文
Hinas A Reimegård J Wagner EG Nellen W Ambros VR Söderbom F 《Nucleic acids research》2007,35(20):6714-6726
Small RNAs play crucial roles in regulation of gene expression in many eukaryotes. Here, we report the cloning and characterization of 18–26 nt RNAs in the social amoeba Dictyostelium discoideum. This survey uncovered developmentally regulated microRNA candidates whose biogenesis, at least in one case, is dependent on a Dicer homolog, DrnB. Furthermore, we identified a large number of 21 nt RNAs originating from the DIRS-1 retrotransposon, clusters of which have been suggested to constitute centromeres. Small RNAs from another retrotransposon, Skipper, were significantly up-regulated in strains depleted of the second Dicer-like protein, DrnA, and a putative RNA-dependent RNA polymerase, RrpC. In contrast, the expression of DIRS-1 small RNAs was not altered in any of the analyzed strains. This suggests the presence of multiple RNAi pathways in D. discoideum. In addition, we isolated several small RNAs with antisense complementarity to mRNAs. Three of these mRNAs are developmentally regulated. Interestingly, all three corresponding genes express longer antisense RNAs from which the small RNAs may originate. In at least one case, the longer antisense RNA is complementary to the spliced but not the unspliced pre-mRNA, indicating synthesis by an RNA-dependent RNA polymerase. 相似文献
997.
998.
The global role of ppGpp synthesis in morphological differentiation and antibiotic production in <Emphasis Type="Italic">Streptomyces coelicolor</Emphasis> A3(2) 下载免费PDF全文
Background
Regulation of production of the translational apparatus via the stringent factor ppGpp in response to amino acid starvation is conserved in many bacteria. However, in addition to this core function, it is clear that ppGpp also exhibits genus-specific regulatory effects. In this study we used Affymetrix GeneChips to more fully characterize the regulatory influence of ppGpp synthesis on the biology of Streptomyces coelicolor A3(2), with emphasis on the control of antibiotic biosynthesis and morphological differentiation. 相似文献999.
Bianca Altvater Silke Landmeier Sibylle Pscherer Jaane Temme Heribert Juergens Martin Pule Claudia Rossig 《Cancer immunology, immunotherapy : CII》2009,58(12):1991-2001
Regulatory NK cell receptors can contribute to antigen-specific adaptive immune responses by modulating T cell receptor (TCR)-induced
T cell activation. We investigated the potential of the NK cell receptor 2B4 (CD244) to enhance tumor antigen-induced activation
of human T cells. 2B4 is a member of the CD2 receptor subfamily with both activating and inhibitory functions in NK cells.
In T cells, its expression is positively associated with the acquisition of a cytolytic effector memory phenotype. Recombinant
chimeric receptors that link extracellular single-chain Fv fragments specific for the tumor-associated surface antigens CD19
and GD2 to the signaling domains of human 2B4 and/or TCRζ were expressed in non-specifically activated peripheral blood T cells by
retroviral gene transfer. While 2B4 signaling alone failed to induce T cell effector functions or proliferation, it significantly
augmented the antigen-specific activation responses induced by TCRζ. 2B4 costimulation did not affect the predominant effector
memory phenotype of expanding T cells, nor did it increase the proportion of T cells with regulatory phenotype (CD4+CD25hiFoxP3+). These data support a costimulatory role for 2B4 in human T cell subpopulations. As an amplifier of TCR-mediated signals,
2B4 may provide a powerful new tool for immunotherapy of cancer, promoting sustained activation and proliferation of gene-modified
antitumor T cells. 相似文献
1000.
Aaron G. Carfagnini F. Helen Rodd Kayin B. Jeffers Ashley E. E. Bruce 《Environmental Biology of Fishes》2009,86(3):403-409
Female zebrafish housed in aquaria with spatial complexity (plastic plants) over a 13–16-week period showed reduced levels
of aggressive behavior compared to females in bare tanks. In tanks with plants, there was no relationship between levels of
aggression and fecundity but, in bare tanks, females experiencing the highest levels of aggression showed reduced fecundity.
Our results suggest that it may be beneficial, when maintaining zebrafish at moderate to high densities or working with especially
aggressive strains, to house them in spatially complex conditions. 相似文献