分子标记技术在蕨类植物遗传多样性研究中的应用

简要介绍了蕨类植物的生态类型和生殖方式;回顾了近年来分子标记技术在蕨类植物遗传多样性研究中的应用,主要包括种间亲缘关系和分类学的研究、遗传变异和遗传结构的研究,以及系统发育地理学方面的研究.最后,对蕨类植物遗传多样性研究中存在的一些问题进行了讨论和展望.     

心叶日中花的组织培养与快速繁殖

1植物名称心叶日中花（Mesembryanthemum cordifoliumL．F．）,实验用植株购自苏州市相城区花木城。     

KLF转录因子家族与脂肪细胞分化

Kruppel样转录因子（Kruppel-like factors, KLF）是一类具有锌指结构的转录因子,其典型结构特征是在其羧基端具有3个C2H2锌指结构. KLF广泛参与细胞增殖、凋亡、分化以及胚胎发育等多个生命活动的调控. 近年来脂肪细胞分化研究的结果显示,KLF家族的多个成员参与脂肪细胞分化过程的调控,既有促进脂肪细胞分化的,也有抑制脂肪细胞分化的. 其中KLF4通过与Krox20协同作用,激活C/EBPβ（CCAAT-enhancer-binding protein β）基因表达,促进脂肪细胞分化;KLF5和 KLF15都通过直接结合到氧化物酶增殖体激活受体γ（peroxisome proliferator-activated receptor γ, PPARγ）基因的启动子,激活PPARγ基因表达,促进脂肪细胞分化;而KLF6则通过抑制前脂肪细胞因子（pre-adipocyte factor 1, PREF1）基因表达,促进脂肪细胞分化. 抑制脂肪细胞分化的KLF2通过结合于PPARγ的启动子,抑制PPARγ基因表达,从而抑制脂肪细胞的分化;KLF3通过募集辅助抑制因子C-末端结合蛋白（c-terminal binding protein, CtBP）形成KLF3 CtBP抑制复合体,结合于C/EBPα（CCAAT-enhancer-binding protein α）基因的启动子,抑制C/EBPα表达,进而抑制脂肪细胞的分化;KLF7通过抑制葡萄糖转运蛋白2（glucose transporter2,GLUT2）基因的表达抑制脂肪细胞的成熟. 本文综述这些KLF转录因子在脂肪细胞分化过程的作用及其作用的机制.     

深色有隔内生真菌（DSE）研究进展

<正>深色有隔内生真菌(dark septate endophytes,DSE)不是一个科学的分类单元,而是泛指一群定殖于植物根内的小型土壤真菌,包括功能和分类关系都不确切的多种真菌。这类真菌的定殖模式在不同植物中是相似的,一般特征是菌丝颜色较深、具     

青稞花药的离体培养与植株再生

1植物名称青稞（Hordeum vulgare L.var nudumHook.f.）。2材料类别小孢子发育时期处于单核期的花药。     

生长相关蛋白GAP-43多肽抗体的制备

目的对生长相关蛋白-43（growth associated proteins-43,GAP-43）进行抗原表位分析并制备兔多克隆抗体。方法通过对GAP-43 cDNA序列及氨基酸序列的结构进行生物信息分析,依据蛋白质的二级结构、亲水性、疏水性、抗原性及理化特性,经过同源性检索后,综合考虑抗体设计的其他因素,选出具有免疫活性的抗原决定簇多肽片段,采用有机固相多肽合成法合成了GAP-43的多肽片段,并与载体蛋白血蓝蛋白（KLH）偶联制备成抗原,免疫新西兰家兔。结果 ELISA测定GAP-43抗体效价为1∶32 000;Western blot检测结果显示：在分子量25kDa出现单一条带;免疫组织化学法检测显示：GAP-43蛋白在小鼠海马神经元中有表达;免疫细胞化学法检测显示：GAP-43蛋白在人神经母细胞瘤株SH-SY5Y中存在表达。结论利用生物信息学软件比较准确地预测GAP-43的抗原决定簇,并成功制备了高效价、高特异性的多肽抗体。     

Insulin-like growth factor 1 protects human neuroblastoma cells SH-EP1 against MPP<Superscript>+</Superscript>-induced apoptosis by AKT/GSK-3β/JNK signaling

Parkinson’s disease (PD) is primarily caused by severe degeneration and loss of dopamine neurons in the substantia nigra pars compacta. Thus, preventing the death of dopaminergic neurons is thought to be a potential strategy to interfere with the development of PD. In the present work, we studied the effect of insulin-like growth factor-1 (IGF-1) on 1-methyl-4-phenylpyridinium (MPP⁺)-induced apoptosis in human neuroblastoma SH-EP1 cells. We found that the PI3K/AKT pathway plays a central role in IGF-mediated cell survival against MPP⁺ neurotoxicity. Furthermore, we demonstrated that the protective effect of AKT is largely dependent on the inactivation of GSK-3β, since inhibition of GSK-3β by its inhibitor, BIO, could mimic the protective effect of IGF-1 on MPP⁺-induced cell death in SH-EP1 cells. Interestingly, the IGF-1 potentiated PI3K/AKT activity is found to negatively regulate the JNK related apoptotic pathway and this negative regulation is further shown to be mediated by AKT-dependent GSK-3β inactivation. Thus, our results demonstrated that IGF-1 protects SH-EP1 cells from MPP⁺-induced apoptotic cell death via PI3K/AKT/GSK-3β pathway, which in turn inhibits MPP⁺-induced JNK activation.     

hTERT启动子调控rVBMDMP基因表达载体的构建与功能研究

为了探讨端粒酶催化亚单位(hTERT)启动子调控重组血管基膜衍生多功能肽(rVBMDMP)基因表达抑制肺癌细胞生长的作用机制,采用PCR方法,克隆hTERT启动子核心区片段,并检测其功能活性.然后,构建pLNSX/hTERT/rVBMDMP逆病毒载体,获取逆病毒,感染肺癌A549细胞,检测hTERT启动子调控rVBMDMP基因表达对细胞形态、细胞生长、细胞凋亡以及Caspase-3表达的影响.另外,观察hTERT启动子调控rVBMDMP基因表达对裸鼠成瘤的抑制作用、瘤组织细胞的凋亡及Caspase-3表达情况.结果发现:a.hTERT启动子核心区能调控rVBMDMP基因的表达(n=3,P<0.05);b.hTERT启动子调控rVBMDMP基因的表达具有抑制肺癌A549细胞的生长和裸鼠成瘤作用(n=6,P<0.05);c.rVBMDMP基因表达能促进肺癌A549细胞凋亡和Caspase-3蛋白表达.以上结果说明,hTERT启动子调控rVBMDMP基因表达后,通过提高Caspase-3的表达水平,促进细胞凋亡而抑制肺癌A549细胞的生长.     

Roles of cortactin, an actin polymerization mediator, in cell endocytosis

Cortactin, an actin-binding protein and a substrate of Src, is encoded by the EMS 1 oncogene. Cortactin is known to activate Arp2/3 complex-mediated actin polymerization and interact with dynamin, a large GTPase and proline rich domain-containing protein. Transferrin endocytosis was significantly reduced in cells by knock-down of cortactin expression as well as in vivo introduction of cortactin immunoreagents. Cortactin-dynamin interaction displayed morphologically dynamic co-distribution with a change in the endocytosis level in cells treated with an actin depolymerization reagent, cytochalasin D. In an in vitro beads assay, a branched actin network was recruited onto dynamin-coated beads in a cortactin Src homology domain 3 （SH3）-dependent manner. In addition, cortactin was found to function in the late stage of clathrin coated vesicle formation. Taken together, cortactin is required for optimal clathrin mediated endocytosis in a dynamin directed manner.     

Hierarchical modularity of nested bow-ties in metabolic networks

Background  

The exploration of the structural topology and the organizing principles of genome-based large-scale metabolic networks is essential for studying possible relations between structure and functionality of metabolic networks. Topological analysis of graph models has often been applied to study the structural characteristics of complex metabolic networks.