马铃薯杂种F1的SSR鉴定

为选育抗黑痣病、高产优质的马铃薯新品种,选用引进品种‘大西洋’分别与‘陇薯6号’、‘陇薯7号’杂交,获得了杂种F1代,利用SSR标记技术对‘大西洋’与‘陇薯6号’的42个杂种F1、‘大西洋’与‘陇薯7号’的9个杂种F1单株进行了鉴定。从59对SSR引物中筛选出2对在亲本间存在差异、扩增稳定、条带清晰的引物S184和STM1049,用于‘大西洋’ב陇薯6号’杂种F1、‘大西洋’ב陇薯7号’杂种F1及其亲本的基因组DNA扩增。SSR带型分析显示,杂种F1的SSR带型呈双亲互补型、缺失型、父本型和母本型4类,依据带型特征鉴定出供试的51个马铃薯杂种F1单株均为真杂种,表明SSR分子标记技术用于马铃薯杂种真实性鉴定是可行的。该研究可为进一步开展马铃薯杂交后代目标性状优异株系选育提供依据。     

CCI大鼠坐骨神经损伤区内中终球与重链神经微丝蛋白的检测

为探寻CCI大鼠坐骨神经损伤区内终球的存在,了解其与重链神经微丝蛋白(heavy neurofilaments,NF-H)分布、表达的联系.通过对雄性SD大鼠的坐骨神经慢性压迫损伤(chronic constriction injury,CCI)组与对照组(对侧正常坐骨神经)进行不同时间点电镜、免疫组化及Western-blotting等方法的观察与检测.研究发现,与对照组相比,CCI模型组大鼠术后4 d损伤坐骨神经中NF的分布较非手术侧有明显变化,术后7、14 d电镜观察到损伤区中枢侧终球样结构,术后4、7、14、28 d CCI模型组大鼠坐骨神经中NF-H表达水平有动态变化(P<0.01).结果表明CCI大鼠模型损伤坐骨神经中NF-H其分布有明显变化,且分布于终球样结构中,其表达随损伤时间有动态变化,这些变化可能参与终球的形成以及与病理性疼痛机制相关联.     

调控p53蛋白的转录因子

肿瘤抑制因子p53被称为"分子警察",它在维持细胞正常生长及抑制恶性增殖过程中起重要作用。p53的表达水平受多种因素影响,其中转录水平的调控是基因发挥功能的一个重要步骤。因此,针对调控p53蛋白的转录因子这一环节阐明p53发挥功能的分子机理,有望为肿瘤治疗、预防和新药研发提供新的靶标。本文着重对调控p53蛋白的转录因子进行综述。     

云南烟蚜抗药性机制研究

通过比较云南烟蚜敏感品系和抗性品系的解毒酶(α-乙酸萘酯羧酸酯酶、β-乙酸萘酯羧酸酯酶)和靶标酶(乙酰胆碱酯酶)的活力,研究了烟蚜对有机磷、拟除虫菊酯和氨基甲酸酯类杀虫剂抗性的生化机制,并通过酯酶基因扩增检测和钠离子通道突变检测,研究了其抗性的分子机制。结果表明:α-乙酸萘酯羧酸酯酶活力增强是烟蚜对有机磷类、氨基甲酸酯类杀虫剂及拟除虫菊酯类杀虫剂的抗性机制之一;乙酰胆碱酯酶在烟蚜对有机磷杀虫剂抗性中起重要作用;3个抗性品系烟蚜均没有发生酯酶基因扩增,抗拟除虫菊酯品系烟蚜发生了钠离子通道突变。     

Edaravone protects against MPP+ -induced cytotoxicity in rat primary cultured astrocytes via inhibition of mitochondrial apoptotic pathway

Edaravone (Eda) is a potent scavenger of hydroxyl radicals and has been demonstrated to be beneficial for patients with acute ischemic stroke. This study was set out to investigate whether Eda protect against MPP(+)-induced cytotoxicity in rat primary cultured astrocytes. The results showed that pre-treatment with Eda inhibited astrocytic apoptosis and lactate dehydrogenase release induced by MPP(+) (200 microM). Further study revealed that Eda prevented GSH depletion, down-regulated mRNA expressions of NADPH oxidase membrane subunit gp91 and membrane-translocated subunit p47, and prevented the decreases of state 3 respiration respiration and respiratory control ratio induced by MPP(+), and thereby inhibited reactive oxygen species production evoked by MPP(+). Moreover, Eda could ameliorate mitochondrial respiratory function, restrain, and prevent mitochondrial membrane potential loss induced by MPP(+). Consequently, Eda inhibited releases of cytochrome c and apoptosis-inducing factor induced by MPP(+). Taken together, these findings reveal for the first time that Eda protects against MPP(+)-induced astrocytic apoptosis via decreasing intracellular reactive oxygen species level and subsequently inhibiting mitochondrial apoptotic pathway. The antiapoptosis effects of Eda on astrocytes may provide a new perspective on neuroprotective therapy.     

Development and characterization of microsatellite loci for lotus (Nelumbo nucifera)

This paper reports the development of microsatellite primers for Nelumbo nucifera Gaerten. By screening genomic libraries enriched with 10 kinds of probes, Seventeen polymorphic loci were isolated and primers were designed. Polymorphism of these 17 loci was assessed in 24 individuals. All the 17 loci are polymorphic and the number of alleles ranged from two to seven. Observed heterozygosity and expected heterozygosity ranged from 0.0000 to 0.9176 and from 0.2837 to 0.7917 respectively. These microsatellite loci should be useful for studying the genetic diversity of N. nucifera.     

Identification of microRNA precursors with support vector machine and string kernel

MicroRNAs （miRNAs） are one family of short （21-23 nt） regulatory non-coding RNAs processed from long （70-110 nt） miRNA precursors （pre-miRNAs）. Identifying true and false precursors plays an important role in computational identification of miRNAs. Some numerical features have been extracted from precursor sequences and their secondary structures to suit some classification methods; however, they may lose some usefully discriminative information hidden in sequences and structures. In this study, pre-miRNA sequences and their secondary structures are directly used to construct an exponential kernel based on weighted Levenshtein distance between two sequences. This string kernel is then combined with support vector machine （SVM） for detecting true and false pre-miRNAs. Based on 331 training samples of true and false human pre-miRNAs, 2 key parameters in SVM are selected by 5-fold cross validation and grid search, and 5 realizations with different 5-fold partitions are executed. Among 16 independent test sets from 3 human, 8 animal, 2 plant, 1 virus, and 2 artificially false human pre-miRNAs, our method statistically outperforms the previous SVM-based technique on 11 sets, including 3 human, 7 animal, and 1 false human pre-miRNAs. In particular, premiRNAs with multiple loops that were usually excluded in the previous work are correctly identified in this study with an accuracy of 92.66%.     

虚拟筛选与新药发现

虚拟筛选是创新药物研究的新方法和新技术,近年来引起了研究机构和制药公司的高度重视,并且已经成为一种与高通量筛选互补的实用化工具,加入到了创新药物研究的工作流程(pipeline)中。本文介绍国际上虚拟筛选及其在创新药物发现中应用的研究进展,特别介绍了我国这方面研究的状况。     

Biotransformation of 14-deacetoxyl sinenxan A by Ginkgo cell suspension cultures and the cytotoxic activity evaluation

14-Deacetoxyl sinenxan A [2,5,10β-triacetoxy-4(20),11-taxadiene, 1] was converted to two new products, 10β-hydroxy-2,5-diacetoxy-4(20),11-taxadiene (2) and 10β-butyloxy-2,5-diacetoxy-4(20),11-taxadiene (3) both about in 20% yields by Ginkgo cell suspension cultures. Their structures were identified on the basis of their chemical and spectroscopic data. The three compounds (1–3) were preliminarily evaluated for their in vitro cytotoxic activities against two solid tumor cell lines and their drug-resistant counterparts (KB and KB/V, MCF-7 and MCF-7/ADR), and the decreased activities were observed in the case of the two products. The results suggested that biotransformation might be a valuable approach to diversifying natural products and provide some useful information on the study on the structure–activity relationships of the type of compounds.     

Ac/Ds(GUS)结构介导的水稻启动子捕获系统的建立

构建了基于Activator/Dissociation(β-glucuronidase)[简称Ac/Ds(GUS)]结构的捕获质粒p13B,用于分离水稻基因启动子.以此质粒用衣杆菌介导的方法转化粳稻品种中花11的胚性愈伤组织,对获得的18个独立转化株的T2代植株进行了抗除草剂筛选,从141个抗除草剂转基因植株中用PCR方法检测到其中37株是Ds因子发生了转座的植株,而且这种转座到新位置上的Ds因子是遗传的.初步观察到其中5株的GUS染色呈阳性.