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101.
植酸对稻米品质影响的研究(Ⅰ) 总被引:2,自引:0,他引:2
本文报道在水稻生长的抽穗期、齐穗期、灌浆期和蜡熟期喷施不同浓度植酸改良稻米品质的研究。结果表明,在水稻生长的不同阶段,控制喷施植酸浓度可提高糙米率,降低稻米垩白。 相似文献
102.
记述采自江西的蚌螨属1新种,定名为丰城蚌螨Unionicola(Parasitatax)fengchengensis sp.nov.和1个中国新纪录种。 相似文献
103.
Abrogation of the Fc gamma receptor IIA-mediated phagocytic signal by stem-loop Syk antisense oligonucleotides. 总被引:4,自引:0,他引:4
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M Matsuda J G Park D C Wang S Hunter P Chien A D Schreiber 《Molecular biology of the cell》1996,7(7):1095-1106
The role of Syk kinase in Fc gamma receptor (Fc gamma R) IIA-mediated phagocytosis was examined with two forms of antisense oligodeoxynucleotides (ODNs) designed to hybridize to human Syk mRNA. Monocytes were incubated with linear and stem-loop antisense ODNs targeted to Syk mRNA. When complexed with cationic liposomes, stem-loop Syk antisense ODN with phosphorothioate modification exhibited stability in fetal bovine and human serum. The stem-loop Syk antisense ODN at a concentration of 0.2 microM inhibited Fc gamma RIIA-mediated phagocytosis by 90% and completely eliminated Syk mRNA and protein in monocytes, whereas scrambled-control ODNs had no effect. The Syk antisense ODNs did not change beta-actin mRNA levels and Fc gamma RII cell-surface expression. In addition, stem-loop Syk antisense ODN inhibited Fc gamma RI and Fc gamma RIIIA-mediated phagocytosis. These data indicate the efficacy of stem-loop Syk antisense ODN for targeting and degrading Syk mRNA and protein and the importance of Syk kinase in Fc gamma receptor-mediated phagocytosis. Immunoblotting assay demonstrated that Fc gamma RII tyrosine phosphorylation after Fc gamma RII cross-linking did not change in the absence of Syk protein. These results indicate that Syk kinase is required for Fc gamma RIIA-mediated phagocytic signaling and that Fc gamma RII cross-linking leads to tyrosine phosphorylation of Fc gamma RII independent of Syk kinase. 相似文献
104.
乳链菌肽的分离纯化和部分生物学性质 总被引:1,自引:0,他引:1
用乳酸链球菌SM526进行乳链菌肽的发酵生产,产量为40~50mg/l.经中空纤维超滤器超滤,非极性大孔吸附树脂XAD-2层析,CM-SephadexC-25层析和SephadexG-50层析纯化了该肽。SDS-PAGE表明达均一,RP-HPLC表明其纯度不低于95%。SDS-PAGE测其Mr约为3600,用IEF测其等电点为9.5.酸性条件下稳定且抗热;对胰蛋白酶、胃蛋白酶和木瓜蛋白酶不敏感,但对α-胰凝乳酶和蛋白酶K敏感。乳链菌肽对多种革兰氏阳性菌有强烈的抑制作用;以枯草杆菌和金黄色葡萄球菌为指示菌,其作用方式是杀菌。 相似文献
105.
Cysteine sulfinic acid decarboxylase (CSAD), the rate-limiting enzyme in taurine biosynthesis, appears to be present in the brain in multiple isoforms. Two distinct forms of CSAD, referred to as CSAD I and CSAD II, were obtained on Sephadex G-100 column. CSAD I and CSAD II differ in (1) the elution profile on Sephadex G-100 column; (2) the sensitivity towards Mn2+, methione, and other sulfur-containing amino acids and (3) their immunologic properties. CSAD II has been purified to about 2,500-fold by a combination of column chromatographies and polyacrylamide gel electrophoresis (PAGE). The purity of the enzyme preparation was established as judged from the following observations: (1) a single protein band was observed under various electrophoretic conditions, e.g., 5–20% nondenaturing PAGE, 7% nondenaturing PAGE and 10% SDS-PAGE and (2) in nondenaturing PAGE, the protein band comigrated with CSAD activity. CSAD II has a molecular weight of 90 kDa and is a homodimer consisting of two 43 ± 2 kDa subunits. CSAD appears to require Mn2+ for its maximum activity. Other divalent cations fail to replace Mn2+ in activation of CSAD activity. However, the precise role of Mn2+ in the action of CSAD remains to be determined. 相似文献
106.
Inheritance of gusA and neo genes in transgenic rice 总被引:21,自引:0,他引:21
Jianying Peng Fujiang Wen Richard L. Lister Thomas K. Hodges 《Plant molecular biology》1995,27(1):91-104
Inheritance of foreign genes neo and gusA in rice (Oryza sativa L. cv. IR54 and Radon) has been investigated in three different primary (T0) transformants and their progeny plants. T0 plants were obtained by co-transforming protoplasts from two different rice suspension cultures with the neomycin phosphotransferase II gene [neo or aph (3) II] and the -glucuronidase gene (uidA or gusA) residing on separate chimeric plasmid constructs. The suspension cultures were derived from callus of immature embryos of indica variety IR54 and japonica variety Radon. One transgenic line of Radon (AR2) contained neo driven by the CaMV 35S promoter and gusA driven by the rice actin promoter. A second Radon line (R3) contained neo driven by the CaMV 35S promoter and gusA driven by a promoter of the rice tungro bacilliform virus. The third transgenic line, IR54-1, contained neo driven by the CaMV 35S promoter and gusA driven by the CaMV 35S.Inheritance of the transgenes in progeny of the transgenic rice was investigated by Southern blot analysis and enzyme assays. Southern blot analysis of genomic DNA showed that, regardless of copy numbers of the transgenes in the plant genome and the fact that the two transgenes resided on two different plasmids before transformation, the introduced gusA and neo genes were stably transmitted from one generation to another and co-inherited together in transgenic rice progeny plants derived from self-pollination. Analysis of GUS and NPT II activities in T1 to T2 plants provided evidence that inheritance of the gusA and neo genes was in a Mendelian fashion in one plant line (AR2), and in an irregular fashion in the two other plant lines (R3 and IR54-1). Homozygous progeny plants expressing the gusA and neo genes were obtained in the T2 generation of AR2, but the homozygous state was not found in the other two lines of transgenic rice. 相似文献
107.
108.
云南普通马矮型马蛋白多态性及其品种分化关系 总被引:3,自引:1,他引:2
本文运用蛋白电泳技术对来自云南省文山州马关县和麻栗坡县的21匹普通马和14匹矮型马进行了分析。共分析遗传座位44个,其中有10个座位检测到多态性。根据分子钟假说和相应的公式,推算两者的分歧时间约为18.5万年。 相似文献
109.
110.
The amphotropic murine leukemia virus receptor gene encodes a 71-kilodalton protein that is induced by phosphate depletion. 总被引:2,自引:2,他引:0
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The amphotropic murine leukemia virus (MuLV) can infect cells from a number of mammals, including humans, via its specific receptor. Basic knowledge of amphotropic MuLV receptor expression is likely to be useful in the development and improvement of gene therapy protocols based on amphotropic-pseudotyped vectors. To investigate the expression of the human receptor for the amphotropic MuLV (GLVR-2, newly termed Pit2), we determined its mRNA levels in several cell lines and found them to vary significantly. Induction of increased levels of mRNA after removal of phosphate from the media was observed in two osteosarcoma cell lines. The increase in GLVR-2 mRNA resulted in a concomitant rise in the levels of a 71-kDa protein specifically recognized by affinity-purified antibodies against GLVR-2. Using these antibodies, we were able to confirm the intracellular topology of the large hydrophilic domain between the proposed sixth and seventh transmembrane domains of the GLVR-2 protein. This assignment is in agreement with the fourth extracellular loop being outside the cell, consistent with the proposal that the fourth extracellular loop of GLVR-2 contains the envelope binding site. 相似文献