利用甲基化特异性引物高通量检测DNA甲基化

建立一种基于甲基化特异性引物和SAGE技术的高通量DNA甲基化定量检测新方法（MSP-SAGE）,首先利用亚硫酸氢钠对基因组DNA进行处理,使未甲基化的C转变为U,而甲基化的CpG不变.将处理和未处理的DNA双链变性后用随机引物PNNNNCG对存在含有CG的单链进行延伸,而无甲基化CG的单链处则不能延伸;将差异延伸的单链序列和频次信息经过系列分子操作后,引入PCR扩增模板;对中间带有未知序列的PCR扩增产物进行串连克隆测序.将来自于未处理组和处理组的某一CpG位点的序列出现的次数定义为［Tags］A和［Tags］B,将标准系列的实际甲基化水平和［Tags］B/［Tags］A之间建立线性回归方程.根据每一CpG位点的［Tags］B/［Tags］A比值可反推该位点的甲基化水平.MSP-SAGE具有良好的线性,基于标准系列的［Tags］B/［Tags］A与其实际甲基化水平的标准曲线方程为y＝1.455x（R²＝0.984,P<0.01）.MSP-SAGE的回收率在95%到110%之间,精确度位于4.2％和10.5%,检测限在3％左右,单次检测通量可达24个CpG位点.MSP-SAGE是一种很有应用前途的高通量DNA甲基化定量检测方法.     

灰飞虱室内大量繁殖及越冬饲养方法

灰飞虱Laodelphax striatellus(Falln)作为多种植物病毒病的传毒介体,近年来发生数量呈逐年增加趋势,给水稻生产造成严重损失。杀虫剂室内毒力测定和抗性选育工作的顺利进行,必须长期饲养大量的标准试虫。文章介绍采用稻苗饲养室内大量繁殖灰飞虱的方法,饲养盒的使用使该方法更加方便,而越冬用麦苗饲养更接近田间的实际情况。     

Design and synthesis of piperazine acetate podophyllotoxin ester derivatives targeting tubulin depolymerization as new anticancer agents

In this paper, a series of podophyllotoxin piperazine acetate ester derivatives were synthesized and investigated due to their antiproliferation activity on different human cancer cell lines. Among the congeners, C5 manifested prominent cytotoxicity towards the cancer cells, without causing damage on the non-cancer cells through inhibiting tubulin assembly and having high selectively causing damage on the human breast (MCF-7) cell line (IC₅₀ = 2.78 ± 0.15 μM). Treatments of MCF-7 cells with C5 resulted in cell cycle arrest in G2/M phase and microtubule network disruption. Moreover, regarding the expression of cell cycle relative proteins CDK1, a protein required for mitotic initiation was up-regulated. Besides, Cyclin A, Cyclin B1 and Cyclin D1 proteins were down-regulated. Meanwhile, it seems that the effect of C5 on MCF-7 cells apoptosis inducing was observed to be not obvious enough. In addition, docking analysis demonstrated that the congeners occupy the colchicine binding pocket of tubulin.     

中国特有濒危树种毛红椿核心和边缘居群的遗传多样性

选用8对多态的微卫星引物, 研究了毛红椿(Toona ciliata var. pubescens)核心居群和边缘居群的遗传多样性。研究结果显示, 边缘居群的观察等位基因数和有效等位基因数并不比核心居群低, 甚至更高。普通广布和稀有地方等位基因在所有居群中均有分布, 而普通地方和稀有广布等位基因分别仅在5个和3个居群中有分布。从4种类型等位基因总数上看, 边缘居群高于核心居群, 特别是边缘居群的稀有地方等位基因数量明显多于核心居群。边缘居群的平均期望杂合度和观察杂合度都高于核心居群。核心居群间的基因分化系数为0.1520, 边缘居群间为0.3045, 边缘居群与核心居群的遗传分化差异达到显著水平。核心居群间基因流大于1, 而边缘居群间基因流小于1, 说明核心居群间基因交流频繁, 边缘居群由于片段化和地形影响, 基因流较小。Mantel检验结果显示, 居群间遗传距离与地理距离的相关性不显著, 说明地理距离对毛红椿居群遗传分化的影响不显著。     

甜菜夜蛾对氯氟氰菊酯抗性的表皮穿透机理

用三种方法测定了采自南京江浦的甜菜夜蛾Spodoptera exigua对氯氟氰菊酯的抗性。结果表明,抗性水平的次序为3龄幼虫点滴法（5 499.5倍）和5龄幼虫点滴法（3 973.2倍）＞3龄幼虫浸叶法（1 041.6倍）＞5龄幼虫叶片夹毒法（24.7倍）,因此该品系触杀毒力的抗性水平至少为胃毒毒力LD50的160倍。用¹⁴C标记氯氟氰菊酯测定甜菜夜蛾抗性和敏感品系5龄幼虫表皮穿透率结果表明,处理后8h,抗性品系5龄幼虫的表皮穿透率仅为敏感品系幼虫表皮穿透率的55.5%。证实表皮穿透率的降低是产生抗性的一个重要机理。     

Structure of the Mitochondrial DNA Control Region of the Sinipercine Fishes and Their Phylogenetic Relationship

The mitochondrial DNA control region of Siniperca chuatsi, S. kneri, S. scherzeri, S. obscura, S. undulata, Coreosiniperca roulei and Coreoperca whiteheadi were amplified by PCR amplification and directly sequenced. The mtDNA control region of the sinipercine fishes could be separated into three domains, namely, the terminal associated sequence domain, the central conserved sequence domain and the conserved sequence block domain. The extended terminal associated sequence (ETAS), three conserved sequence blocks (CSB-F, CSB-E, CSB-D) in the central conserved sequence domain and three conserved sequence blocks (CSB1, CSB2, CSB3) in the conserved sequence block domain were also identified. The phylogenetic relationships among these sinipercine fishes were constructed through neighbor-joining and maximum parsimony methods using Percidae and Serranidae as outgroups. Results showed that sinipercine fishes were a monophyletic group, with Siniperca forming one group, and Coreoperca forming another group. Coreosiniperca roulei did not form an independent group but was merged into the genus Siniperca. Thus it should be renamed as Siniperca roulei.     

Methionine restriction enhances the chemotherapeutic sensitivity of colorectal cancer stem cells by miR-320d/c-Myc axis

Molecular and Cellular Biochemistry - Chemotherapy resistance of colorectal cancer stem cells (CRC-SCs) has become a major challenge in clinical treatment of cancer. Methionine restriction (MR)...