(1) Barnase、Barstar基因和TA29基因5'区调控顺序的PCR扩增、克隆和测序（2）水稻花粉核蛋白因子与TA29基因5'区调控顺序的相互作用

本文运用PCR技术，分别从烟草和B. amyloliquefaciens的基因组DNA中扩增出了TA29基因5'区调控顺序、Barnase和Barstar基因，克隆后进行序列分析，表明其核苷酸顺序与文献报道的一致，然后进行了初步的融合基因的构建。另外，凝胶滞后实验表明，水稻花粉（含绒毡层组织）细胞核中某种蛋白因子能够与TA29基因5'区调控顺序发生特异的结合。本文还对TA29基因5'区调控顺序及Barnase和Barstar基因的潜在应用价值和存在的问题进行了讨论。

Expression of syncytin in leukemia and lymphoma cells

Syncytin is a placenta-specific protein and generally believed to play a pivotal role in syncytiotrophoblast morphogenesis. In this study, transcripts of this gene were quantified by real-time RT-PCR and the translated products were measured by an indirect immunofluorescence assay. Results showed that syncytin was found to be expressed in all nine leukemia and lymphoma cell lines studied albeit at different levels and in 43 peripheral blood samples of 57 leukemia or lymphoma patients. Neither the transcripts nor the translated syncytin was detected in blood samples of normal individuals. In conclusion, peripheral blood syncytin may serve as a marker for leukemia and lymphoma. ©

A colorimetric assay for screening microcystin class compounds in aquatic systems

Secondary metabolites produced by water-blooming cyanobacteria in eutrophic waters include some potent hepatotoxins, These compounds also have tumour-promoting properties, attributable to their inhibition and activation of protein phosphatases and kinases respectively. The inhibitory effect of these toxins on protein phosphatases have been employed in a commonly used radiometric assay, involving the use of a P-32-labeled substrate, for the detection and quantitation of these compounds. This paper investigates and describes a colorimetric method in which the activity of protein phosphatase 2A is determined by measuring the rate of colour production from the release of yellow p-nitrophenol using p-nitrophenyl phosphate as the substrate. Results of this study suggest that the colorimetric protein phosphatase inhibition assay is a simple, inexpensive tool for screening substances that may have tumour-promoting characteristics in aquatic systems. The detection limit of the colorimetric method is comparable to the radiometric assay. (C) 1998 Elsevier Science Ltd. All rights reserved.

Frankia的REP-PCR、RAPD-PCR鉴定及遗传多样性研究

本文采用溶菌酶法、CTAB法、微波法及CTAB+微波法等4种方法进行Frankia菌Cp11基因组DNA的提取。结果表明四种方式均可行，但以CTAB法及微波法最为有效。提取方法与REP-PCR带型间关系的研究表明，方法上的差异不会影响到REP-PCR带型的变化。对14株Frankia菌株作REP-PCR分析，并对之进行比较分类，证明REP-PCR方法不但能实现菌株间的差异鉴别，还能有效地进行Frankia菌的分类。这一结果与DNA同源相关性所得的分类结果具有良好的相关性。选用20个随机引物，对分自2个分类接种群的8株Frankia纯培养的总DNA进行随机扩增。其中引物OPW15和OPW16能扩增得到较为稳定的RAPD图谱。扩增产物分子量大都分布在0.5-4Kb之间。从稳定的RAPD扩增图谱看，Frankia菌间存在有丰富的遗传多样性；在选定适当引物情况下，能依据共同带型将Frankia菌化归为同一分类接种群。

rep-PCR对赤杨根瘤内局Frankia菌基因多样性研究

本文应用重复基因外回纹序列rep-PCR方法直接扩增长日山三种不同赤杨和云南不同地区早冬瓜根瘤内的Frankia菌基因，所获得的REP指纹图谱揭示Frankia菌具有丰富的基因多样性。研究结果表明Frankia菌多样性随地域，海拔，坡问不同而变：多样性指数与自然选抒）玉力大小成正相关：自然选择压力是产生和保持Frankia菌基因多样性的重要因子。同时发现Frankia菌基因型与地域有紧密关系：所观察的云南各地区中，感染高黎贡山旱冬瓜的Frankia菌基因多样性最为丰富。推测与高黎贡山旱冬瓜共生的Frankia可能作为种储备库，为其它地区的寄主植物提供了祖先菌株。在对长白山三种赤杨（东北赤杨，西伯利亚赤杨和色赤杨）根瘤内几百游殆菌基因多样性考察过程中发现，Frankia菌基因类型与寄主赤杨种型关系密切。同时海拔对感染东北赤杨的Frankia菌基因多样性也有一定影响。感染西伯利亚赤杨和色赤杨的Frankia菌享有相同的基因型，可能有较近的亲缘关系。