苹果绵蚜蚜小蜂发育历期、发育起点温度和有效积温的研究

本文以苹果绵蚜为繁殖寄主,研究了苹果绵蚜蚜小蜂在不同温度下的发育历期、发育起点温度和有效积温。结果显示:苹果绵蚜蚜小蜂的发育历期随温度的升高而缩短,最适发育温度为21℃-27℃。山东地区越冬代苹果绵蚜蚜小蜂打破滞育的发育起点温度为雌蜂8.58℃,雄蜂8.22℃;有效积温为雌蜂148.72日度,雄蜂154.68日度。非越冬代苹果绵蚜蚜小蜂在卵-羽化阶段发育起点温度为雌蜂5.62℃,雄蜂5.55℃;有效积温为雌蜂284.40日度,雄蜂为295.61日度。并推测了2008年济南地区苹果绵蚜蚜小蜂发生代数和越冬代羽化时间,与实测情况基本相符。     

菠萝叶片中依赖焦磷酸的磷酸果糖激酶的光/暗调节特性(英文)

植物中D:果糖6—磷酸1—磷酸转移酶(PPi—PFK,EG 2.7.1.90)活性的调节是非常重要的。这主要是因为它能可逆催化糖酵解和生糖两个方向的反应。光照处理菠萝叶片或离体的菠萝叶圆片使PPi—PFK的酶活性增高。与从暗处理的叶片中提取的酶的特性相比,光照处理的叶片中的酶对糖酵解方向催化活性相对增加。暗处理导致酶催化精酵解方向活性的下降。这种反映在酶活性和特性上的变化可为光照重新恢复。结果表明,菠萝叶片的PPi—PFK对体内糖酵解或生糖途径的贡献可能决定于光的状况。     

山茶花叶片DNA提取及RAPD反应体系的研究

山茶花（Camellia japonica L.）是我国特产的名贵花卉之一,由于其品种繁多,在系统分类和品种鉴定上存在一定的难度。本研究针对山茶花的DNA提取方法和RAPD扩增体系进行了摸索,旨在为山茶花在DNA水平的分类鉴定和分子生物学方面研究打下一定的基础。实验采用改进的CTAB法提取山茶花叶片DNA,得到的DNA纯度较高,OD₂₆₀/OD₂₃₀值为1.90～2.0,OD₂₆₀/OD₂₈₀值为1.80～1.83,得率也较高,一般在150～200 μg·g^-1左右,片段完整性较好,大于20 kb,符合分子遗传实验的要求;在山茶花RAPD扩增条件的研究中,发现20 μL反应体系中加入100 ng DNA、125 μmol·L^-1 dNTP(each)、1.2 μmol·L^-1 Mg²⁺、1×Buffer、0.5 μmol·L^-1引物、1 U Taq酶最为合适,退火温度一般设为37℃左右,扩增产物的电泳条带数多、清晰、明亮。     

Molecular analysis of thymopentin binding to HLA-DR molecules

Thymopentin (TP5) triggers an immune response by contacting with T cells; however the molecular basis of how TP5 achieves this process remains incompletely understood. According to the main idea of immunomodulation, we suppose that it would be necessary for TP5 to form complex with human class II major histocompatibility complex DR molecules (HLA-DR) before TP5 interacts with T cells. The uptake of TP5 by EBV-transformed B cells expressing HLA-DR molecules and the histogram of fluorescence intensities were observed by using fluorescent- labeled TP5, testifying the direct binding of TP5 to HLA-DR. The binding specificity was confirmed by the inhibition with unlabeled TP5, suggesting the recognition of TP5 by HLA-DR. To confirm the interaction between TP5 and HLA-DR, the complex formation was predicted by using various modeling strategies including six groups of trials with different parameters, alanine substitutions of TP5, and the mutants of HLA-DR. The results demonstrated that TP5 and its alanine substitutions assumed distinct conformations when they bound to HLA-DR. The observation further showed that there was flexibility in how the peptide bound within the binding cleft. Also, the molecular analysis supplemented a newly important discovery to the effect of Val anchor on TP5 binding HLA-DR, and revealed the important effects of Glu11 and Asn62 on the recognition of TP5. These results demonstrated the capability of TP5 to associate with HLA-DR in living antigen presenting cells (APC), thereby providing a new and promising strategy to understand the immunomodulation mechanism induced by TP5 and to design potential immunoregulatory polypeptides.     

MDCK cell-cultured influenza virus vaccine protects mice from lethal challenge with different influenza viruses

Influenza epidemics are major health concern worldwide. Vaccination is the major strategy to protect the general population from a pandemic. Currently, most influenza vaccines are manufactured using chicken embroynated eggs, but this manufacturing method has potential limitations, and cell-based vaccines offer a number of advantages over the traditional method. We reported here using the scalable bioreactor to produce pandemic influenza virus vaccine in a Madin-Darby canine kidney cell culture system. In the 7.5-L bioreactor, the cell concentration reached to 3.2 × 10(6) cells/mL and the highest virus titers of 256 HAU/50 μL and 1 × 10(7) TCID50/mL. The HA concentration was found to be 11.2 μg/mL. The vaccines produced by the cell-cultured system induced neutralization antibodies, cross-reactive T-cell responses, and were protective in a mouse model against different lethal influenza virus challenge. These data indicate that microcarrier-based cell-cultured influenza virus vaccine manufacture system in scalable bioreactor could be used to produce effective pandemic influenza virus vaccines.     

小分子RNA在植物叶发育中的调控作用

叶发育是叶原基细胞有序的分裂、生长和分化的过程,受到植物激素和多个转录因子的严格调控.近年的研究表明,在叶片发育的过程中,小分子RNA是基因调控网络的重要组分.小分子RNA通过对其中一些转录因子的抑制作用,影响其表达水平和空间分布,维持叶的正常发育.本综述介绍了小分子RNA及其靶基因调控模块在叶片发生、 叶片形状、叶子极性发育和叶子衰老等过程中的调控作用,并展望了未来研究中新方向.     

基因谱系示踪揭示小鼠Tbx18+肾脏间质祖细胞分化为输尿管平滑肌

本文旨在研究Tbx18+肾脏间质祖细胞分化为输尿管平滑肌细胞的命运及转录因子Tbx18在小鼠输尿管平滑肌发育形成中起到的作用．实验建立Tbx18:Cre/R26REYFP和Tbx18:Cre/R26RLacZ两种谱系示踪系统和Tbx18:Cre/Cre 敲除模型．该示踪模型通过cre重组酶的表达能有效地示踪Tbx18+肾脏间质祖细胞在泌尿系统的发育命运．通过免疫荧光染色和X-gal染色,同时发现Tbx18+肾脏间质祖细胞可分化为输尿管平滑肌细胞,但不分化为输尿管移行上皮细胞．在Tbx18:Cre/Cre基因突变模型中,泌尿系统出现明显的肾积水和输尿管积水,肾盏、肾盂扩张,输尿管明显缩短和扩张．实验结果揭示,Tbx18+ 肾脏间质祖细胞可以分化为输尿管平滑肌细胞,且转录因子Tbx18在哺乳动物输尿管平滑肌的发育中起到重要的作用．     

EGF-mediated migration signaling activated by N-acetylglucosaminyltransferase-V via receptor protein tyrosine phosphatase kappa

N-acetylglucosaminyltransferase-V (GnT-V) has been reported to be closely associated with tumor migration, but the mechanism has been not currently clear. In this study we found that GnT-V activated EGFR signaling and promoted cell migration through receptor protein tyrosine phosphatase kappa (RPTPκ). The overexpression of GnT-V gene in human hepatoma SMMC-7721 cell line not only induced the addition of β1,6 GlcNAc branch to N-glycan of RPTPκ but also decreased the protein level of RPTPκ, which both contributed to the decreased phosphatase activity of RPTPκ activating subsequently EGFR signaling. Moreover, we found that the knockdown of RPTPκ and its addition of β1,6 GlcNAc branch both promoted cell migration, which could be ascribed to the activation of EGFR signaling regulated by RPTPκ. Therefore, our findings could provide an insight into the molecular mechanism of how GnT-V promoted cell migration, suggesting that RPTPκ could be one of factors regulating the EGF-mediated migration signals.     

大豆皂甙抗癌活性研究进展

本文就大豆皂甙的抗癌活性研究进展进行概述,并对未来研究方向进行了展望.     

肿瘤对自然杀伤细胞的杀伤敏感性研究

自然杀伤细胞（NK细胞）是机体抗肿瘤的第一道防线,是机体天然免疫的主要承担者,也是获得性细胞免疫的核心调节细胞。NK细胞对肿瘤的杀伤活性与其细胞表面受体和肿瘤细胞表面的配体密切相关,由于肿瘤细胞表面配体表达不同致使对NK细胞杀伤的敏感性有很大差异,临床疗效不一。我们简要介绍了影响肿瘤细胞对NK细胞杀伤敏感性的机制,对目前提高肿瘤细胞敏感性的策略和方法进行了总结。