Genetic ecology: A new interdisciplinary science,fundamental for evolution,biodiversity and biosafety evaluations

Genetic ecology is the extension of our modern knowledge in molecular genetics to studies of viability, gene expression and gene movements in natural environments like soils, aquifers and digestive tracts. In such milieux, the horizontal transfer of plasmid-borne genes between phylogenetically distant species has already been found to be much more frequent than had been expected from laboratory experience. For the study of exchanges involving chromosomally-located genes, more has to be learned about the behaviour of transposons in such environments. The results expected from studies in genetic ecology are relevant for considerations of evolution, biodiversity and biosafety. The role of this new field of research in restoring popular confidence in science and in its biotechnological applications is stressed.     

邻羧基苯基重氮氨基偶氮苯与镉的显色反应及该类衍生物结构与吸光性能的关系

新试剂邻羧基苯基重氮氨基偶氮苯对镉有灵敏显色反应,摩尔吸光系数可达1.94×10~6升·摩尔~(-1)·厘米~(-1)。本文报导了它的合成及吸光性能。又通过十六种新合成的该类衍生物与镉的显色反应,发现了不同结构的各类取代基与吸光性能关系的规律性。     

广义双正则函数向量的带共轭值的非线性边值问题

利用积分方程的方法和Schauder不动点原理，讨论了实Clifford分析中广义双正则函数向量的带共轭值的非线性边值问题解的存在性及其积分表达式。     

位点特异性频率模型在昆虫分子系统发育分析中的应用

根据位点特异性频率模型(site-specific rate model),利用PAUP软件,对线粒体COI基因序列不同密码子位点的数据模块分别进行了豉甲科和水生肉食亚目在亚科或科水平上的系统发育学分析,结果表明第二密码子数据模块获得的系统分析结果与形态学分析结果一致。表明位点特异性频率模型在线粒体COI基因作为标记来进行昆虫分子系统发育分析上获得了更好的效果。     

Co-transformation to tobacco of Cre/lox site-specific recombination system and its precise recombination

For the temporally and spatially regulated expression of the barnase gene in plant, two kinds of plasmids with cre gene and its directly repeat recognition sitesiox from bacteriophage P1 were constructed and co-transformed into tobacco by agrobacterium mediated procedure. The transgenic plants were conformed by PCR analysis. The blocking fragment between the twolox directly repeat sites was excised by Cre protein in the transgenic plant genome. Cloning and sequencing the DNA fragment from the co-transformed plant DNA showed that the precise DNA excision occurred in transgenic tobacco genome directed by Cre/lox site-specific recombination.     

关于变参数广义系统拓扑熵的研究

给出了变参数广义系统的拓扑熵的开覆盖定义与Bowen定义,并讨论了它的性质与计算.证明了在紧致度量空间上2种定义下的拓扑熵是等价的,并且广义拓扑熵仍然是拓扑共轭不变量.     

染色体位置对酵母SUC2基因表达的影响

通过ＦＬＰ－ＦＲＴ位点特异性ＤＮＡ切离和ＤＮＡ定点整合技术,将酵母蔗糖酶基因整合到酿酒酵母染色体不同位置上,测定了ＳＵＣ２基因表达情况,从而对酵母染色体位置效应进行了初步研究。     

线面共轭法计算回转刀具廓形及其包络面

线面共轭法是一种简化的计算方法,用于计算加工一些特殊曲面如螺旋面、铲磨面的回转刀具廓形及其包络面.根据被加工曲面上的一条已识曲线和拟定的加工运动,文中提出了计算回转刀具廓形及其被加工曲面的数学模型.     

苏云金芽孢杆菌高效菌株cry基因分析及多价基因组合的研究

对本室筛选的高活性Ｂ．ｔ．野生株进行了ｃｒｙ 基因检测,Ｓｏｕｔｈｅｒｎ杂交证明ｃｒｙＩＡｃ和ｃｒｙ１Ｃ位于质粒上．利用接合转移和电穿孔转化等方法对这些菌株进行了遗传改良研究．结果表明：高效野生株７４０４、ＨＤ－１－Ｘ和９５１０ 不易获得并表达外源ｃｒｙ 基因,而高效野生株Ｂｔｉ． ｔ－１８９７ 的电转化频率较高,并获得以Ｂｔｉｔ－１８９７ 为受体,对甜菜夜蛾、棉铃虫、黏虫和淡色库蚊均有毒力,具有ｃｒｙＩＡｃ、ｃｒｙＩＣ、ｃｒｙＩＶ及ｃｙｔ多价基因的广谱工程菌株．