喜马拉雅土拨鼠非冬眠期乳酸脱氢酶同工酶基因表达特征

用聚丙烯酰胺凝胶电泳和紫外光谱法分析非冬眠期喜马拉雅土拨鼠4种组织的乳酸脱氢酶(LDH)同工酶的酶谱及其活力,该鼠骨骼肌酶带的多态分布,可能是潜在的调节基因调控所致。另外,本文还对构象异构体产生的亚带进行了研讨。     

Construction of a recombinant human GM-CSF/MCAF fusion protein and study on its in vitro and in vivo antitumor effects

A novel cytokine fusion protein was constructed by fusing granulocyte macrophage colony stimulat-ing factor (GM-CSF) with monocyte chemotactic activating factor (MCAF), which acts as a factor directing effector cells (monocytes) to a target site. The recombinant human GM-CSF/MCAF fusion protein could sustain the growth of GM-CSF-dependent cell line TF1 and was chemotactic for monocytes. The in vitro antitumor effect showed that rhGM-CSF/MCAF could activate monocytes to inhibit the growth of several human tumor cell lines, including a promyelocyte leukemia cell line HL-60, a lung adenocarcinoma cell line A549, a hepatoma cell line SMMC-7721 and a melanoma cell line Bowes. Furthermore, the cytotoxicity of monocytes activated by rhGM-CSF/MCAF against HL-60 and A549 was greater than that activated by GM-CSF or MCAF alone, even greater than that activated by a combina-tion of GM-CSF and MCAF, suggesting that the fusion protein has synergistic or enhanced effects. The in vivo anti-tumor effect indicated that     

农业景观中非农景观要素结构特征对植物物种多样性的影响——以封丘县为例

农业景观中的非农生境对维持与提高农业景观的生物多样性具有非常关键的作用。为了探究非农生境的相关结构属性对农业景观中植物物种多样性的影响,选择黄河下游平原区的封丘县为研究区域,对研究区内42个样点的非农生境进行植物多样性调查,并对各个样点周围1 km范围内的非农景观要素进行了提取,分析不同非农生境中植物物种组成及其景观要素的构成、结构及空间配置对植物物种多样性的影响。研究结果表明:不同类型的非农生境中,物种组成共有种相对较多,特有种或指示种较少;林地与树篱具有相对较高的物种多样性,以沟渠为生境的植物物种组成与其它两种生境类型相比存在明显差异;林地与树篱/沟渠的组成比例相当时,植物物种丰富度最高;景观指数对不同非农生境中的植物物种具有明显影响,景观破碎化及人为干扰指数的影响较为显著。未来在对本区域内农业景观进行结构优化的过程中,应从非农景观要素的改造入手。通过调整和设置非农景观要素的不同类型及比例、合理改造其结构与空间配置,为最终实现农业景观的有效管理与可持续健康发展奠定重要的研究基础。     

重组人GM－CSF／MCAF融合蛋白抗血清的制备与鉴定

重组人粒细胞巨噬细胞集落刺激因子（ＧＭ－ＣＳＦ）和人单核细胞趋化激活因子（ＭＣＡＦ）融合蛋白经ＳｅｐｈａｄｅｘＧ－７５和ＣＭ－ＳｅｐｈａｒｏｓｅＦＦ两步柱层析,获得了电泳纯的ＧＭ－ＣＳＦ／ＭＣＡＦ融合蛋白。为进一步研究其结构与功能,我们以纯化的该融合蛋白为抗原免疫家兔制备抗血清。ＤｏｔＥＬＩＳＡ和Ｗｅｓｔｅｒｎｂｌｏｔ试验表明,该抗血清效价高、特异性好,可分别与ＧＭ－ＣＳＦ／ＭＣＡＦ、ＧＭ－ＣＳＦ和ＭＣＡＦ发生反应。     

Construction of a trivalent candidate Shigella vaccine strain with host-vector balanced-lethal system

A trivalent liveShigella vaccine candidate FSD01 against S.flexneri 2a, S.sonnei and S.dysenteriae I was constructed. This candidate strain was based on the S.flexneri 2a vaccine T32. By homologous recombination exchange, the chromosomalasd gene of T32 was site-specifically inactivated, resulting in the strain unable to grow normally in LB broth, while anotherasd gene of S.mutans was employed to construct an Asd⁺ complementary vector. This combination ofasd ^- host/Asd⁺ vector formed a balanced-lethal expression system in T32 strain. By use of this system, two important protective antigen genes coding for S.sonnei Form I antigen and Shiga toxin B subunit were cloned and expressed in T32, which led to the construction of trivalent candidate vaccine FSD01. Experimental results showed that this strain was genetically stable, but its recombinant plasmid was non-resistant. Moreover, it was able to effectively express trivalent antigens in one host and induce protective responses in mice against the challenges of the above threeShigella strains.     

不同干扰背景下景观指数与物种多样性的多尺度效应——以巩义市为例

以黄河中下游山地丘陵区的巩义市为研究区,采用典型样地法对灌草丛、人工林和农田边缘3种不同干扰背景下的自然、半自然生境内的植物进行调查。基于景观生态学原理,在地理信息系统技术支持下,借助于Fragstatta3.3软件,以调查样地为中心,计算了150、250、500、750、1000、1250、1500m不同半径缓冲区内表征景观形状(Edge and patch shape)、边缘对照(Edge contrast)、相似度和邻近度(Proximity and similarity)、景观多样性(Diversity)、基质(Texture)、斑块大小和密度(Patch size and patch density)共6类52个指数,运用冗余分析(RDA)筛选出不同尺度下对该区农业景观中植物多样性有显著影响的景观指数。结果表明:不同尺度,景观指数对物种多样性的影响变化显著。灌草丛生境,在500—750m范围内,SHAPE_AM指数和PARA_AM指数能够很好的解释物种多样性,解释量为33.6%;人工林生境,SHAPE_AM指数、AREA_CV指数、SIMI指数和PAFRAC指数在1000—1250m范围内对物种多样性的解释量达到48.1%;农田边缘生境,GYRATE_CV指数、ENN_CV指数、PARA_MN指数和FRAC_AM指数在750—1250m范围内对物种多样性影响显著,解释量为32%。其中,辛普森多样性指数(SIDI)与灌草丛物种多样性在750—1250m范围内作用显著,ENN_CV指数仅对农田边缘物种多样性影响较大。景观指数对物种多样性的影响具有尺度依赖性,未来应全面综合探讨这些指数的尺度效应及在景观生态学中的应用。     

Unusual lipids and acylglucosylsterols from the roots of Livistona chinensis

A 70% ethanol extract from the roots of Livistona chinensis has been investigated, led to the isolation of 18 compounds, including two new 6′-O-acyl-β-d-glucosyl-β-sitosterols, 6′-O-(2″-hydroxyheptadecanoyl)-β-d-glucosyl-β-sitosterol (1) and 6′-O-(icosa-9″Z,12″Z-dienoyl)-β-d-glucosyl-β-sitosterol (2), two new keto esters, ethyl 16-(dodeca-4″′Z,7″′Z-dienyl)-29-oxo-15-(tetradeca-5″Z,8″Z,11″Z-trienyl) triacontanoate (7), and 16-hydroxy-8-oxohexadecyl tetradecanoate (9), a new unsaturated fatty acid, tetracosa-(11Z,14Z,18Z)-trienoic acid (8), as well as a new fatty alcohol, 10-decylnonadecane-1,19-diol (10). The structures of new compounds were elucidated, based on spectroscopic and chemical methods. The antiproliferative activity against four human tumor cell lines (K562, HL-60, HepG2, and CNE-1) was evaluated. Four compounds (1–3, 5) showed potent antiproliferative effects with the IC₅₀ of 10–100 μM. To our knowledge, this is the first report of the occurrence of 6′-O-acyl-β-d-glucosyl-β-sitosterol and 3-O-acyl-β-sitosterol in the genus Livistona. Keto fatty acids and their esters are also rare in higher plant.     

OsGL1-3 is Involved in Cuticular Wax Biosynthesis and Tolerance to Water Deficit in Rice

Cuticular wax covers aerial organs of plants and functions as the outermost barrier against non-stomatal water loss. We reported here the functional characterization of the Glossy1(GL1)-homologous gene OsGL1-3 in rice using overexpression and RNAi transgenic rice plants. OsGL1-3 gene was ubiquitously expressed at different level in rice plants except root and its expression was up-regulated under ABA and PEG treatments. The transient expression of OsGL1-3–GFP fusion protein indicated that OsGL1-3 is mainly localized in the plasma membrane. Compared to the wild type, overexpression rice plants exhibited stunted growth, more wax crystallization on leaf surface, and significantly increased total cuticular wax load due to the prominent changes of C₃₀–C₃₂ aldehydes and C₃₀ primary alcohols. While the RNAi knockdown mutant of OsGL1-3 exhibited no significant difference in plant height, but less wax crystallization and decreased total cuticular wax accumulation on leaf surface. All these evidences, together with the effects of OsGL1-3 on the expression of some wax synthesis related genes, suggest that OsGL1-3 is involved in cuticular wax biosynthesis. Overexpression of OsGL1-3 decreased chlorophyll leaching and water loss rate whereas increased tolerance to water deficit at both seedling and late-tillering stages, suggesting an important role of OsGL1-3 in drought tolerance.