The antibody preparation and expression of human Pescadillo

To explore the biological roles of human Pescadillo and investigate its potential effect on tumorigene sis, the eDNA of Pescadillo was fused with that of GST. After purification and elution, the purified GST-Pescadillo fusion protein was obtained, and the antibody against the fusion protein was generated.Endogenous Pescadillo protein was observed to be remarkably induced by estrogen. It was mainly distributed in the tissues such as breast, ovary and intestine, all of which contain proliferating cells,and was also detected in many cell lines of human cancer: renal carcinoma, hepatoma, ovarian cancer,colon carcinoma, and breast cancer. The expression level of Pescadillo was increased significantly in breast cancer tissues compared with their paired margin tissues. Taken together, these data suggest that Pescadillo may play important roles in the initiation and development of cancer and may be a potential target in cancer diagnosis and therapy.     

不同小麦品种茎秆特性及其与抗倒性的关系

以黄淮麦区优良品种矮抗58、周麦18、豫麦49、百农418为研究对象,采用田间试验与实验室分析相结合的方法,对不同小麦品种在不同生育时期的抗倒伏性状进行研究.结果表明: 茎秆机械强度在开花期至花后20 d处于较高水平,在花后30 d明显下降;倒伏指数在开花期最小,花后30 d最大,其余两个时期处于中间水平.相关分析表明,开花期机械强度与重心高度呈显著负相关,与纤维素、木质素含量呈显著正相关,倒伏指数与节长、株高、重心高度呈显著正相关,与纤维素、木质素含量呈显著负相关;花后10 d和花后20 d机械强度与节长、株高、重心高度呈显著负相关,与茎粗、纤维素、半纤维素、木质素含量呈显著正相关,倒伏指数这段时期正好与之相反;花后30 d机械强度与株高、重心高度呈显著负相关,倒伏指数与株高、重心高度呈显著正相关,与木质素含量呈显著负相关.因此,明确各个生育时期与抗倒性相关的茎秆特性,可为黄淮麦区高产抗倒性品种的选育提供依据.     

崇明东滩南部河口盐沼植物群落种间关系的数量分析

对崇明东滩南部盐沼植物群落样方进行调查,基于现有17种高等植物,特别是8种常见植物的2×2联列表和植被盖度值,利用方差比率法、χ²检验以及Spearman秩相关分析对物种关联性和相关性进行分析.结果表明: 方差比率(VR=0.61)的检验统计量W=48.61,落在 χ² 2个临界值区间之外,因此该区域盐沼植物群落内植物整体关联度表现为显著负相关;依据各优势植物对环境的适应方式和生境的主导因素,参考Spearman秩相关分析的结果,将它们划分为4个生态种组: 芦苇、糙叶苔草-藨草-水莎草、互花米草-海三棱藨草、白茅-稗草.崇明东滩南部盐沼植物群落种间关系复杂,群落表现极不稳定,植物对于环境影响较为敏感.在明确物种之间关系的基础上,针对海三棱藨草的分布现状提出了相应种群的保护措施和建议.     

谷氨酸棒杆菌/大肠杆菌穿梭型启动子探测载体构建

从质粒pXZ10145和pUC19出发,构建了一个谷氨酸棒杆菌/大肠杆菌穿梭载体pAK6。pAK6的大小为5684bp,带有卡那霉素和氨苄青霉素抗性选择标记,以及多克隆位点。在pAK6基础上,构建了以氯霉素乙酰转移酶为报告基因的启动子探测载体pAKC6,pAKC6的大小为6474bp。采用鸟枪法,将经Sau3AI消化的谷氨酸棒杆菌基因组片段连入pAKC6;根据谷氨酸棒杆菌对氯霉素的抗性,从中分离出两个具有启动子功能的插入片段。通过测定报告基因氯霉素乙酰转移酶的活性,对两个启动子片段在谷氨酸棒杆菌中的强度进行了初步的判断;测序后,用启动子预测软件对其结构进行了预测,证实了启动子序列的存在。     

不同视觉经验中zif268基因的表达模式

zif268基因编码一转录因子ZIF268. 在发育的视皮层中,zif268基因的表达模式受发育的调节. 在具有正常视觉经验的视皮层中,zif268基因有较高水平的表达. 视觉废置后,视皮层内该基因的表达水平显著降低. 通过视觉刺激可显著增强该基因的表达. 有关zif268基因表达模式的研究对于阐明该基因在哺乳动物视觉系统中的生理功能起到借鉴的作用.     

在肾癌细胞系GRC-1细胞周期不同阶段Wnt-5A基因的表达情况

Wnt基因所编码的蛋白质与许多生长因子一样具有分泌型生长因子的结构特点,其家族成员Wnt-5A是许多恶性肿瘤的自分泌生长因子,在肾细胞癌中表达显著升高.为研究在细胞周期的不同阶段生长因子Wnt-5A在转录水平的表达情况,我们采用胸腺嘧啶双阻断及高压笑气处理的方法,使肾细胞癌细胞系GRC-1细胞同步化.用半定量反转录多聚酶链反应对处于细胞周期不同阶段的细胞cDNA进行扩增,S期与G1,M期Wnt-5A mRNA表达存在差异显著(P＜0.05）.结果提示生长因子Wnt-5A在肾细胞癌的发生中具有潜在的作用,在S期作用可能尤为显著.     

Preparation and epitope characterization of monoclonal antibodies against firefly luciferase

The 6-His tagged firefly luciferase was highly expressed in E. coli and purified to homogeneity by affinity chromatography and gel filtration. After immunizing Balb/c mice with the antigen, 6 hybridomas clones were found to secrete monoelonal antibodies (mAbs) and the mAbs were also purified separately. The competitive binding experiments show that 2 mAbs can bind heat-denatured antigen or its proteolytic fragments but not the native lueiferase, suggesting that their epitopes might be accommodated in the internal segments of the protein. On the other hand, the other 4 mAbs are capable of binding both native and denatured antigens. It infers that their epitopes locate in the segments on the protein surface. The results also suggest that the six mAbs are all sequence-specific.     

Studies on solution NMR structure of brazzein——Secondary structure and molecular scaffold

Brazzein is a sweet-tasting protein isolated from the fruit of West African plantPentadiplandra brazzeana Baillon. It is the smallest and the most water-soluble sweet protein discovered so far and is highly thermostable. The proton NMR study of brazzein at 600 MHz (pH 3.5, 300 K) is presented. The complete sequence specific assignments of the individual backbone and sidechain proton resonances were achieved using through-bond and through-space connectivities obtained from standard two-dimensional NMR techniques. The secondary structure of brazzein contains one alpha-helix (residues 21-29), one short 3(10)-helix (residues 14-17), two strands of antiparallel beta-sheet (residues 34-39, 44-50) and probably a third strand (residues 5-7) near the N-terminus. A comparative analysis found that brazzein shares a so-called 'cysteine-stabilized alpha-beta' (CSalphabeta) motif with scorpion neurotoxins, insect defensins and plant gamma - thionins. The significance of this multi-function motif, the possible active sites and the structural basis of themostability were discussed.     

转基因在玉米中的遗传分离与整合特性的研究

用ＰＣＲ和ＤＮＡ分子杂交方法研究了转基因Ｂｔ在３种不同方法获得的８个转化体后代中的遗传分离、整合性质及其稳定性,结果表明：（１）转基因在大多数转化体后中呈简单的孟德尔遗传;在Ｒ１至Ｒ２代,部分家系中转化体比例偏低,有的发生转基因丢失,但到Ｒ３代以后均趋于正常的孟德尔遗传方式,在群体中固定下来;（２）转基因在不同转化体中的整合类型有一定差异,但整合的位点和拷贝数都较少,且多呈串联或紧密连锁的整合;（