A Modified Cooling Method and its Application in Drosophila Experiments

Chilling is a cost-effective and safe method of immobilising flies in Drosophila experiments. However, should condensation form on the plate, it would be fatal to the flies. Here we describe a modified cooling method using reusable commercial ice pack(s) (ca. 400 ml, 2–3 cm tall) rather than crushed ice. The ice pack is covered with a piece of filter paper which absorbs the condensed water formed on the cold surface, and the moistened filter paper does not wet the wings of flies inverted onto it. An ice pack (ca. 400 ml) takes effect in at least 1 h, and its height is shorter than the maximum specimen height of a dissecting microscope, so that flies can be checked while they remain on the cold surface. This method overcomes the disadvantages of the indigenous cooling anaesthetising approach and makes it practically feasible. We also describe an easy-to-make fly-transferring toolkit which will greatly facilitate fly transferral when it is combined with our chilling method. In our design, the flies were directed out of a vial by a blue pipette tip, which is inserted in a foam stopper and channelled down into another vial by a glass funnel inserted in another foam stopper which is escape-proof.     

石油集输系统中微生物群落结构研究

采用16SrRNA基因克隆一变性梯度凝胶电泳分析方法研究了石油集输系统原油和油田产水中的微生物群落结构。变性梯度凝胶电泳图谱显示：油田产水中微生物群落远比原油中的菌群丰富。所有的油田水样和原油样本中都存在与Ochrobactrum sp．和Stenotrophomonas sp．相关的细菌;原油样本中检测出与Burkholderia sp．、Brevundimonas sp．和Propionibacterium sp．相关的细菌,而这些细菌在油田水样中未检出;在油田水样中检出与Hippea sp．、Acidovorax sp．、Arcobacter sp．、Pseudomonas sp．、Thiomicrospira sp．、Brevibacterium sp．、Tissierella sp．和Peptostreptococcus sp．相关的细菌,而这些细菌在原油样本中未检出。用古细菌特异性引物进行检测发现在油田水样中存在与Methanomicrobials和Methanosarcinales相关的产甲烷菌,而这些细菌在原油样本中未检出。在石油集输过程中,油田水样和原油中微生物群落的相似性分别为83．3％和88．2％,说明微生物群落结构较为稳定。     

去甲万古霉素生产菌株Amycolatopsis orientalis遗传操作体系的建立

为了对去甲万古霉素高产菌中的功能基因进行研究,以整合型p ZMW为载体,考察了去甲万古霉素生产菌东方拟无枝酸菌属间接合转移限制因素,优化3个关键限制因素:产孢培养基为YD,起始孢子量控制在1×10~8~4×10~8/反应,抗生素覆盖时间为16~17 h为宜。建立了东方拟无枝酸菌生产菌株NCPC 2-48的操作方法和培养条件,使体内分析该菌的生物合成及调控基因的功能成为可能,并为建立其他放线菌遗传操作体系提供了参考。     

A survey on cytosolic non-enzymic proteins involved in the metabolism of lipophilic compounds: from organic anion binders to new protein families

This review deals with recent advances in the research of cytosolic non-enzymic proteins involved in the metabolism of lipophilic compounds. Emphasis is given to the important contribution of structural data in the understanding of the functional properties of these proteins and in the emergence of new protein families. The possibility that many of the 'cytosolic' proteins might be structure-bound and structure-forming in the living cell is discussed, with references to so far available structural data and to recent investigations on the architecture and biochemical composition of the cytoplasm. The aim of this review is to present in a condensed form (227 references) the evolution in the study of cytosolic proteins binding and transferring lipophilic compounds and to enable interested investigators to become aware of current concepts and perspectives in this active and steadily growing area of research.     

生态补偿区域的空间选择研究——以青海省国家重点生态功能区转移支付为例

生态补偿区域的空间选择研究是生态补偿机制建立的基础,目前国内缺少这方面的研究。合理的生态补偿区域空间选择方法可以为生态补偿优先地区的选择提供较为可靠的定量化依据。综合考虑青海省各市县的生态系统服务价值和经济发展水平,在使用Arc GIS工具的基础上,运用"生态效益比瞄准"方法和"生态补偿优先级(Eco-compensation Priority Sequence,ECPS)"方法,分别对青海省各市县生态补偿优先等级进行了研究。研究结果表明:"生态效益比瞄准"方法适用于森林、草原等基于要素的生态补偿机制的空间选择,而"生态补偿优先级"方法更适合区域性的生态补偿的空间选择。根据"生态补偿优先级"方法可以得出青海省国家重点生态功能区转移支付优先补偿区主要集中在青海省南部,次级补偿区主要位于青海省中部,潜在补偿区主要在青海省东北部。与青海省重点生态功能区转移支付资金分配比较,海西州内的很多市县没有得到相应的补偿,原有的资金分配方式更多的考虑民生因素而忽略了环境因素。在生态补偿区域的空间选择中,要结合生态综合补偿,提出合理的生态补偿绩效考核体系,在保护环境的基础上改善民生。     

Low temperature solution behaviour of Methylophilus methylotrophus electron transferring flavoprotein: a study by analytical ultracentrifugation

The solution behaviour of electron transferring flavoprotein (ETF) from Methylophilus methylotrophus was investigated at low temperature (4 °C) by analytical ultracentrifugation. The concentration dependence of the apparent weight average molecular weight, M_w,app, established the existence of the protein in heterodimeric state (M = 63,700 Da), but also signified the possible dissociation of the heterodimer at lower concentrations into its constituent subunits (M = 28,900 Da and 33,700 Da, together with FAD and AMP cofactors of collective M = 1120 Da). This similarity in subunit size allows approximate quantification of the dissociation in terms of expressions for a monomer-dimer equilibrium. The dissociative behaviour was confirmed by determination of the point average molecular weight, M_w,app(r), as a function of the ETF concentration, c(r), throughout the sedimentation equilibrium distributions obtained with loading concentrations of 0.4 and 0.7 mg/ml. By means of the recently formulated ``psi' procedure for direct analysis of solute self-association a value of (1.5 ± 0.1) μM has been obtained for the dissociation constant K_d. Sedimentation velocity experiments yielded an estimate of the heterodimer sedimentation coefficient, s⁰ _20,w, of (4.5 ± 0.2) S which for M = 63,700 Da suggests a globular structure. Received: 29 November 1996 / Accepted: 2 December 1996     

光（温）敏核雄性不育水稻育性转换中幼穗和花药的某些生理指标变化

光（温）敏核雄性不育水稻（Ｐｈｏｔｏｐｅｒｉｏｄ／ｔｅｍｐｅｒａｔｕｒｅ－ｓｅｎｓｉｔｉｖｅｇｅｎｉｃｍａｌｅ－ｓｔｅｒｉｌｅｒｉｃｅ,简称Ｐ／ＴＧＭＲ）８９０２５和培矮６４ｓ在秋季从不育阶段经半不育阶段向可育阶段转变进程中,对其花粉母细胞形成期（Ⅴ）、花粉母细胞减数分裂期（Ⅵ）的幼穗和成熟花药（Ⅷ）中过氧化物酶（Ｐｅｒｏｘｉｄｓｅ,简称ＰＯＤ）、超氧物歧化酶（Ｓｕｐｅｒｏｘｉｄｅｄｉｓｍｕｔａｓｅ,简称ＳＯＤ）．和过氧化氢酶（Ｃａｔａｌａｓｅ,简称ＣＡＴ）活性测定表明,幼穗和花药相同发育时期的酶活性随正常花粉的比率升高而增加,但以成熟花药中增加最多．并伴有丙二醛（Ｍａｌｏｎａｌｄｅｈｙｄｅ,简称ＭＤＡ）含量减少．表明自由基代谢的变化可能与光（温）敏核雄性不育水稻花粉败育有关,且自由基代谢变化在幼穗发育中期即已开始．     

南水北调中线水源区浮游植物与水质评价

通过2003年3月至2005年8月对南水北调中线水源区水体浮游植物的调查,结果表明:该水域共有浮游植物8门63属96种及变种,其中以硅藻的种类最多,其次是绿藻和蓝藻。藻类的细胞密度表现出明显的季节变化,夏季最高冬季最低。从近3年的浮游生物检测结果可知,整个水源区年平均藻类细胞密度为109.33×10⁴ cells·L^-1,处于较低的水平,而且未检出水体重污染指示种,充分说明南水北调中线水源区富营养化程度较低。运用Margalef和Menkinick多样性指数对该水域的水质进行评价,数据显示2003~2005年该水源区的d值和α值,各采样点之间的差异并不显著,说明各采样点的水质营养状况虽有差异,但总体水平基本相当。水质评价结果:水体为寡污型,基本处于中营养状态。通过水生生物资源的调查,做好水源区的长期生态监测,可为建立中线水源区长期生态研究数据信息库及库区生态环境保护政策制定提供理论依据,对保证中线水质质量十分重要。