Molecular cloning and structural analysis of a novel Rac gene osRACB in rice (Oryza sativa L.)

Rac is a subfamily of small GTP-binding protein family. Its molecular weight is between 20 and 30 kilodaltons. As a signal protein, Rac directly or indirectly participates in many physiological processes, such as the regulation of cytoskeleton and the transduction of stress-induced signal. So Rac is also named ?molecular switch? The switch is based on the cycle from a GTP-bound 憃n?to a GDP-bound 憃ff?state[1]. In the superfamily of GTP-binding protein, only heterotrimeric G protein, Ra…     

转高粱C4型NADP-ME基因水稻植株的光合生理特征

NADP-苹果酸酶(NADP-ME)是C4型植物C4光合途径的一个关键酶。利用RT-PCR结合筛选cDNA文库技术,分离得到了编码高粱(SorghumvulgareL.)C4型NADP-ME的全长cDNA。该cDNA全长为2139bp,其开放可读框为1911bp,共编码636个氨基酸和一个终止密码子(GenBank登陆号为AY274836)。利用农杆菌介导的转化系统将其转入水稻品种“农垦58”。经Southern杂交、Northern杂交和酶活性检测表明,高粱C4型NADP-ME可以在水稻中有效表达,酶活性可被提高1~7倍。对转基因水稻进行光合生理检测表明,转NADP-ME基因水稻CO2交换特征没有明显改变,但是在中午强光条件下光抑制加剧。     

草鱼和鲤鱼线粒体 DNA 的分离纯化及其 COI 基因的分子克隆

本文报道配合使用差速离心和DNaseI核酸酶处理等步骤,从草鱼和鲤鱼新鲜肝组织分离线粒体DNA(mtDNA)的实验方法。这种方法经济简便,纯化的mtDNA产率多,纯度高,经限制性内切酶消化后进行琼脂糖凝胶电泳分离,可以得到清晰的DNA片段谱带,并可直接用于构建酶切图谱和线粒体基因的分子克隆。用这样的mtDNA,我们已克隆了草鱼和鲤鱼的细胞色素氧化酶亚基I基因(COI基因)。     

在转基因植物中实现外源基因最佳表达的途径

引言大约最近十年左右的时间,许多重要植物品种的遗传转化相继获得了成功,并再生出可育的转基因植株。迄今为止,应用生物弹击法或农杆菌介导法,已经转化了５０种以上的不同植物。但是有一些重要的粮食作物诸如小麦和大豆等,其转化效率则有待于进一步的提高。在最近的５年中,已有许多种不同的基因被分别导入了以烟草为主的多种不同的植物。在这类工作中,大多数是使用组成型的启动子（ｃｏｎｓｔｉｔｕｔｉｖｅｐｒｏｍｏ...     

高梁叶绿体psaA基因的克隆和核苷酸序列分析

我们克隆了含高梁叶绿体psaA基因的6．7kb Ec0RI酶切片段,进行了限制酶图谱分析和核苷酸序列结构测定,所测核苷酸序列总长为3080bp,其中高梁叶绿体psaA基因序列为2253bp,编码一个含750个氨基酸残基的蛋白质,其分子量为83000Da。高梁psaA基因的核苷酸序列与玉米、水稻,菠菜的同源性分别为99．4％、96．3％和89．4％;推导出的氨基酸序列的同源性分别为99．3“、98．O％和95．7％。C₄植物与C₃植物比较,由于P 700脱辅基蛋白的第493位氮基酸性质的不同(Gly→Arg,ser),而导致了它们的乡肽在疏水性图谱上的差异。     

著名华裔科学家吴瑞教授的学术成就与贡献

吴瑞教授在ＤＮＡ生物化学和分子生物学的许多领域中做出了杰出的贡献。最重要的一项是他发展了测定ＤＮＡ核苷酸序列的第一个方法。为了使核酸序列分析成为可能,吴瑞教授在１９６８年独创性地设计了一种崭新的引物－延伸策略,并于１９７１年成功地测定了λ噬菌体两个粘...     

Isolation of development-related genes in somatic embryo radicle of carrot (Daucus carota L.) using modified cDNA RDA

Using modified cDNA RDA capitalizing on the high affinity of streptavidin for biotin and magnetic-absorption-based separation, we have obtained four bands of specifically expressed cDNA in the carrot somatic embryo deregulated for 12 h, which were designated as NR-1, NR-2, NR-3 and NR-4, respectively. As revealed by homology analysis of their DNA sequences after cloning them into pBS, remarkable homology was demonstrated in NR-2, NR-3 and NR-4 with the genes coding for LEA (late embryogenesis abundant protein), Dna J and xyloglucan endo-trans-glycosylase in plants. On the other hand, NR-1 showing no homology with any known sequence may have come from unknown genes. Using 32P-labeled NR-1 as probe, hybridization with cDNA fragment population has shown that we have actually cloned a new gene fragment related to radicle development. As shown by further Southern hybridization, these genes may be present in carrot genome in the form of single or low copies.     

深切怀念我的老师吴瑞教授

我敬爱的老师,美国康乃尔大学生化分子生物学系分子生物学及分子遗传学教授吴瑞博士,于2008年2月10日与世长辞.听到这个不幸消息的时候,我无论如何不肯相信这会是真的.然而事实是无情而残酷的.一个多月的时间已经过去,我的心情仍旧难以平静.