间隔臂和探针长度与寡核苷酸芯片重复性相关性研究

研究寡核苷酸芯片的重复性与间隔臂（spacer）和探针长度之间的相关性。设计12条不同长度的带有不同spacer的探针,与749bp荧光标记靶序列杂交。扫描分析三次杂交结果,用Quantrray定量分析软件进行分析,随探针长度的延长,杂交信号的变异系数逐步降低,15mer的探针杂交的信号较弱,杂交不够稳定,重复性也相对较差,20mer、25mer、30mer的探针的变异系数逐渐降低。spacer为15时变异系数最小。说明选择spacer为poly（dT）15的25mer和30mer的探针可以获得较好的重复性。     

Differentiation antigens of hemoblastoses and epithelial tumors: Relations to the mechanisms of transformation and progression

The role of mechanisms underlying differentiation is considered in malignant transformation of hemoblastoses and epithelial tumors. In hemoblastoses, differentiation is intimately related to malignant transformation and they are underlain by the same mechanisms. Immunophenotyping of hemoblastoses is fully based on successive stages of their differentiation with characteristic expression of differentiation antigens. Unlike hemoblastoses, epithelial tumors gradually, in the course of progression, lose their differentiation due to the degradation of the connections with the microenvironment, which controls the direction and level of epithelial differentiation. Therefore, carcinomas are characterized by varying degrees of “antigenic simplification”, including the epithelial-mesenchymal transition.     

Construction of Plant Expression Vector with Double Resistance to Virus and Insect and Identification of Transformation in Tomato

By in situ hybridization of bacterium clone and analysis of restriction enzyme digestion, both CMV-cp gene and Bt-toxin gene were inserted one by one into T-DNA of binary plant expression vector pea. The reconstructed plasmid was named pE14. Then, tomato was transformed with pE14 mediated by Agrobacterium tumefaciens GV311-SE, four regenerated tomato plants were obtained on the MS medium containing 100 μg/mL kanamycin. Assay of nopaline, dot blotting of tomato genomic DNA and PCR amplication of CMV-cp gene and Bt-toxin gene from genomic DNA showed that CMV-cp gene and Bt-toxin gene were transferred into the four regenerated tomato plants simultaneously with T-DNA, and no recombination of genes occurred. RNA dot blotting showed that two of them could express simultaneously the CMV-cp gene and Bt-toxin gene proteins. The resistances to virus and insect of the transgenic tomato plants will be tested in their F1 and F2 regenerations.     

广州市民对蝙蝠和鸟类的认识及食用状况分析

2005年4月,采取随机抽样方式对广州市民进行了蝙蝠和鸟类认识情况和食用状况的问卷调查。用SPSS11．0软件对收回的280份调查问卷的数据进行方差分析和等级变量相关分析,结果显示食用蝙蝠状况与地点、年龄、学历和分数（问卷成绩）的线性相关关系较弱;食用鸟类状况与年龄和学历存在较弱的正线性相关关系,与地点和分数存在较弱的负线性相关关系;而食用蝙蝠状况与食用鸟类状况存在正线性相关关系。本文还对教育在增强公民对野生动物的认识和保护意识中的作用、食用野生动物的危害和保护野生动物的措施等进行了讨论。     

Abscission and thinning of young fruit and thier regulation by plant hormones and bioregulators

Natural abscission of young fruit and its regulation by plant hormones isconsidered and compared to the generally accepted model of senescencetriggered abscission of, for example, leaves or mature fruit. It isconcluded that abscission of young fruit cannot be explained by this model.Alternatively, it is suggested that the senescence triggered initial step inthe classical abscission model should be replaced by a correlativelytriggered step. Polar basipetal IAA transport with its autostimulation andautoinhibition components is the main regulating signal in this correlativeacting system and replaces ethylene as the initial driving force from thesenescence triggered model.Results supporting this model are presented and tested against existingresults from the literature. Finally, this hypothesis is tested as a possibleexplanation of the mode of action of some thinning chemicals orbioregulators. It is speculated how a thinning chemical should be designedto function in a more reliable way, at least as far as its interference with the endogenous hormone system is concerned.     

The developmental profile of paramyosin and other myofibrillar proteins of larval and imaginal thoracic muscles of Lepidoptera

The synthesis of paramyosin and other myofibrillar proteins of the thoracic muscles of the tobacco hornworm Manduca sexta was studied by immunological and electrophoretical methods during the histolysis of the larval thoracic muscles and the differentiation of the indirect flight muscles. Antigens of the myofibrillar proteins in the thoracic muscles of the last-larval stage cross reacted with those in the flight muscles of the adults against polyspecific antibodies from actomyosin and monospecific antibodies from paramyosin. After the breakdown of the larval thoracic muscles (2 days from larval-pupal ecdysis) these antigens can no longer be detected in the thorax. The results indicate an almost complete removal of the larval thoracic muscles. Paramyosin could be identified again in a homogenate of the thoracic muscles of animals on the 13th day from larval-pupal ecdysis. Paramyosin is the first protein found during the differentiation of the flight muscles. The other myofibrillar proteins could be identified in thoracic homogenates of pharate adults of Manduca sexta on the 14th and 15th day from larval-pupal ecdysis. On the 14th day from larval-pupal ecdysis the dorso-longitudinal muscle and the tergosternal muscles show cross-striation, and the appearance of most of the electrophoretical results are in accordance with immunological and morphological findings. The myofibrillar proteins of the indirect flight muscles of Manduca sexta are synthesized de novo during metamorphosis.     

Large scale isolation of bovine and pig zonae pellucidae: Chemical,immunological, and receptor properties

A procedure is described for isolating milligram quantities of bovine and porcine zonae pellucidae, uncontaminated by follicle cells or their processes. On SDS-polyacrylamide gel electrophoresis the isolated bovine zona material formed one major glycoprotein band with an estimated molecular weight of approximately 100,000 daltons and two minor lower molecular weight components. The isolated pig zonae formed only one glycoprotein band with a molecular weight of approximately 62,000 daltons. Rabbit antisera raised against the isolated zonae were zona-specific and formed only a single precipitin line against the heat-solubilized zonae on immunoelectrophoresis. An adjuvant was not required for high-antibody titers. High titers were also obtained by injection of the dog and rhesus monkey. Anti-zona antibody was detected by immunofluorescence, zona-coating, double-immunodiffusion, and the inhibition of spermbinding to eggs, including those of human origin. Antigenic and sperm receptor properties were stable at 100°C for five minutes, but some activity was lost after longer exposure. The serum antibody produced by rabbits immunized with pig zonae was predominantly IgG and cross-reacted with the zonae of a variety of other species, including primates. Pregnancy was inhibited in female rabbits immunized with pig zona preparations.     

Biochemical and Stability Properties of Recombinant Human MnSOD

The light absorption spectral properties of recornbinant human MnSOD. which contains an N-terminal additional methionyl residue, were investigated as a function of pH in the range 4.5–10.5. Whereas the extinction coefficient, ?_M at the UV maximum (282 nm) was essentially independent of pH, the ?_M values of the visible spectrum maximum (482 nm) displayed a bell-shaped dependence with a plateau between pH 6.5 and B. Those spectral changes were reversible and the enzymatic activity was not affected by exposure to buffered solutions at 25°C in the pH range 5–10.5. The stability of MnSOD was determined between 25 and 60°C at two different pH: 6.5 and 8.2. The enzyme was found to be considerably more stable at pH 6.5 than at pH 8.2, both toward aggregation and degradation. The gel permeation properties of MnSOD were investigated: the enzyme is a tetramer, with a subunit of 22.2 kD; however. it elutes from a Superose 12 column (Pharmacia) with an apparent molecular weight of ～60kD. Under dissociative conditions (such as guanidine-HCI). molecular weights corresponding to the dimer and monomer could also be demonstrated. It thus appears that the tetramer adopts a non-globular shape. which causes the deviation from the Stokes radius corresponding to its molecular weight.     

Gelation of high methoxy pectin in the presence of pectin methylesterases and calcium

High methoxy pectin was submitted to various amounts of a fungal pectin methylesterase (PME) from Aspergillus aculeatus and of a plant PME from orange in the presence of calcium. The systems were characterized by rheological means during the gelation process. By the way of in situ demethoxylation with low amount of orange PME, it was possible to gel pectin from the beginning of the reaction although its high degree of methylation around 70. To understand this unusual properties, the behaviour of the two enzymes was investigated in pectic gels and in solution through the analysis of content and distribution of the remaining methyl esters. In the gel, the degree of methylation decreased slowly with orange PME and rapidly with Aspergillus PME. The degree of methylation and degree of blockiness after treatment with each PME in solution or in gels were slightly different. Possible explanations for this are evolving visco-elastic properties, including gel formation or influence of calcium on the enzyme–substrate complex.     

植物抗寒性与抗寒基因的表达和调控

综合概述了国内外有关植物抗寒机理的研究动态,主要讨论了抗寒基因的表达与调控在植物抗寒性中的反应。此外,亦提出了有关植物抗寒机制研究领域值得深入研讨的问题。