Publications by authors named "Kai-xian Qian"

It has been reported that genes encoding antigens of bacterial and viral pathogens can be expressed in plants and are shown to induce protection antibodies. The structural protein E2 of classical swine fever virus (CSFV), which has been shown to carry critical epitopes, has been expressed in different systems. Here, we report the expression of CFSV E2 gene in tobacco chloroplasts.

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The expression vector, pBI121CTBVP1, containing the fusion of the foot and mouth disease virus (FMDV) VP1 gene and the cholera toxin B subunit (CTB) gene was constructed by fused PCR and transferred into potato (Solanum tuberosum L.) by Agrobacterium-mediated transformation. Transformed plants were obtained by selecting on kanamycin-resistant medium strictly and regenerated.

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The expression of classical swine fever virus (CSFV) structural protein E2 in different vectors, which has been shown to carry critical epitopes, has been established. Here, we reported a Chlamydomonas reinhardtii chloroplast expression vector, P64E2, containing classical swine fever virus structural protein E2 gene, which was constructed and transferred to C. reinhardtii by biolistic bombardment method.

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Streptomycetes are Gram-positive, soil-inhabiting bacteria of Actinomycetales. These organisms exhibit complex life cycle and secondary metabolic pathways, and produce many economically important secondary metabolites. This review presented recent progress in Streptomycetes chromosome structure,genomics and the research of secondary metabolic pathway in Streptomyces.

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Neuronal guidance cues attract or repel axons and/or neurons and play important roles in the pathfinding of neuronal networks and the functioning of nervous system. Prominent among them are the families of ephrins, semaphorins, Slits and netrins and their cognate cell-surface receptors. Due to their biological significance, extensive research has been carried out in the last ten years or so.

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Heterogeneous expression of multiple genes in the nucleus of transgenic plants requires the introduction of an individual gene and the subsequent backcross to reconstitute multi-subunit proteins or metabolic pathways. In order to accomplish the expression of multiple genes in a single transformation event, we inserted both large and small subunits of allophycocyanin gene (apcA and apcB) into Chlamydomonas reinhardtii chloroplast expression vector, resulting in papc-S. The constructed vector was then introduced into the chloroplast of C.

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UV irradiated spores of Streptomyces sp. AP 19-1 strain that can produce antibiotics were incubated at 27 degrees C, and 33 degrees C which is close to inhibiting growth temperature, respectively. The results showed that there were much more forward mutants, whose level of producing antibiotics is higher than that of original strain, among the offspring of UV irradiated spores grown at 33 degrees C, compared to that grown at 27 degrees C.

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Article Synopsis
  • Protein splicing is a process that involves intein, a polypeptide, catalyzing its own removal from a pre-protein while simultaneously joining the surrounding polypeptides (exteins) together.
  • This mechanism includes a series of reactions where intramolecular cleavage and ligation occur.
  • Protein splicing enhances our understanding of posttranslational processing and has promising applications in various biotechnological fields.
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Aim: To investigate the effect of schisandrin B (Sch B) on proliferation and apoptosis of human hepatoma SMMC-7721 cells in vitro and regulation of Hsp70 and Caspases-3, 7, 9 expression by Sch B.

Methods: Human hepatoma cell line SMMC-7721 was cultured and treated with Sch B at various concentrations. Growth suppression was detected with MTT colorimetric assay.

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Novel bacterial blight (BB) resistance gene(s) for rice was (were) introduced into a cultivated japonica rice variety Oryza sativa (cv. 8411), via somatic hybridization using the wild rice Oryza meyeriana as the donor of the resistance gene(s). Twenty-nine progenies of somatically hybridized plants were obtained.

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Slit is a secreted protein known to function through the Roundabout (Robo) receptor as a chemorepellent in axon guidance and neuronal migration, and as an inhibitor in leukocyte chemotaxis. Here we show Slit2 expression in a large number of solid tumors and Robo1 expression in vascular endothelial cells. Recombinant Slit2 protein attracted endothelial cells and promoted tube formation in a Robo1- and phosphatidylinositol kinase-dependent manner.

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In the process of nuclear transfer (NT), different cytoplasm from a donor cell and a recipient oocyte are mixed. However, it is unclear what effect the donor cytoplasm has upon the dedifferentiation of donor nuclei in enucleated ooplasm and upon subsequent production of live cloned offspring. Mitochondria are component parts of cytoplasm so the detection of mitochondrial DNA is helpful to reveal changes of donor cytoplasm in the NT reconstructed embryos.

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Transplastomic Plants Homoplasmic for Foreign Transgenes.

Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai)

January 2000

Scientists pay more and more attention to the research on plastid engineering for its following advantages foreign genes can be integrated site-specifically into the plastid genome (plastome) there are no position effects as experienced with random insertion of transgenes in nuclear transformation pollen-mediated dispersion of transgenes can be avoided because chloroplasts are maternally transmitted gene silencing does not occur in plastids and therefore transgene expression is stable in progeny of transplastomic plants and the high ploidy level of the plastome in leaf cells makes high levels of transgene expression feasible. At the same time, however, the highly polyploid plastome makes it difficult to get transplastomic plants homoplasmic for foreign transgenes. In this work, chloroplast transforming vector pTRCH205, which carries two psbA5'-nifH-psbA3'and Prrn-aadA-TpsbA cassettes flanked by plastid DNA sequence to target their insertion between psbA and trnK operons, was constructed.

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P-selectin (CD62P) is expressed on activated platelets and on stimulated endothelial cells. It interacts with P-selectin glycoprotein ligand-1 (PSGL-1; CD162) for adhesion of activated platelets on leukocytes and for rolling of leukocytes on stimulated endothelial cells. Recently, resting and activated platelets have been shown to roll on endothelial P-selectin, indicating that platelets express (a) ligand(s) for P-selectin.

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The erythrocyte membranes were prepared from fresh human blood and 1,6-dipheny1-1,3,5-hexatriene (DPH) was used as a probe to detect their change of fluidity. It was found that after brief irradiation, C(60) remarkably increased the degree of fluorescence polarization of the DPH-labeled erythrocyte membrane, suggesting that C(60) irradiation could greatly reduce the fluidity of erythrocyte membrane. It was also found that the reduction of membrane fluidity was mainly due to the oxidation of sulfhydry groups in the membrane protein and the peroxidation of membrane unsaturated fatty acids.

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