Rice Triosephosphate Isomerase Gene 5[prime] Sequence Directs [beta]-Glucuronidase Activity in Transgenic Tobacco but Requires an Intron for Expression in Rice

In rice (Oryza sativa L.), cytosolic triosephosphate isomerase (TPI) is encoded by a single gene. TPI catalyzes a vital step in glycolysis, and RNA blots showed that the tpi gene is expressed in all vegetative tissues (root, culm, and leaves) and in rice suspension cells. No effect of light on expression was detected, but submergence of rice seedlings resulted in elevated levels of TPI mRNA in roots and culms. The 2767-bp 5[prime] upstream sequence of the tpi gene was fused translationally with the [beta]-glucuronidase (gusA) gene, and the resulting construct, TPI-GUS, was found to express constitutive, high levels of GUS activity in transgenic tobacco (Nicotiana tabacum) plants. However, the same construct yielded no GUS activity in stably transformed rice plants, and RNA blots showed that no GUS mRNA could be detected even though stable integration of functional copies of the construct was confirmed by Southern blot and genomic polymerase chain reaction analyses. Transient assays using particle bombardment yielded high levels of GUS expression from the TPI-GUS construct in tobacco leaves, but essentially no expression in rice, barley, or maize leaves. When the first intron of the tpi gene was included in the construct (TPI-int1-GUS), transient GUS activity was routinely obtained in rice leaves, revealing that the first intron of the rice tpi gene is crucial for its expression in rice. TPI-int1-GUS also directed transient GUS expression in maize and barley leaves, but little or no activity was obtained from this construct in tobacco, tomato, or soybean leaves. These results with the rice tpi promoter are in accordance with mounting evidence that differences in gene expression exist between monocots and dicots.     

Some observations on free ammonia inhibition to Nitrobacter in nitrifying biofilm reactor

Summary Free ammonia inhibition to Nitrobacter population in a nitrifying biofilm was investigated. It was found that when the tree ammonia concentration is greater than 0.1 mgN/l the oxidative activity of Nitrobacter was significantly inhibited, and resulting in a transient accumulation of nitrite ions. The results show that Nitrobacter population is capable of rapidly recovering its lost metabolic activity once the free ammonia concentration becomes less than 0.1 mgN/l, and a complete oxidation of nitrite to nitrate was achieved.     

Response pattern of nitrifying biofilm reactor to shock loading

The effects of shock loading on the performance of a nitrifying biofilm reactor were investigated over a wide range of conditions by varying the feed concentration of ammonium (S_O) and dilution rate (D) respectively. It was found that variation in the effluent ammonium concentration as S_O or D changes was subject to a semi-U shaped curve. The response patterns of the nitrifying biofilm reactor to one-step change in S_O at a constant dilution rate, and to one-step change in D with keeping constant S_O have no significant difference.     

Comparison of techniques for measuring plasmid stability in yeasts

Summary Three techniques for measuring plasmid stability in yeasts are described and evaluated. The yeast used was aKluyveromyces lactis strain which was transformed with a plasmid, pCR1, to enable production of heterologous α-amylase. The techniques were based on plate counts on a selective antibiotic-containing medium and a non-selective medium, and on clearing zones on starch-supplemented plates for α-amylase detection. The plate ratio and clearing zones methods gave comparable results while the transfer colony method estimated much lower plasmid stabilities.     

Modification of sialic acids by 9-O-acetylation is detected in human leucocytes using the lectin property of influenza C virus

Influenza C virus spike glycoprotein HEF specifically recognizesglycoconjugates containing 9-O-acetyl-N-acetylneuraminic acid.The same protein also contains an esterase activity. Takingadvantage of these two properties, influenza C virus was usedas a very sensitive probe for the detection of traces of 9-O-acetyl-N-acetylneuraminicacid in human leucocytes. The binding of influenza C virus toleucocyte glycoproteins and gangliosides separated by sodiumdodecyl sulphate–polyacrylamide gel electrophoresis andthin-layer chromatography, respectively, was assayed using achromogenic esterase substrate. In this way, glycoproteins ofB-lymphocytes and T-lymphocytes were found to contain 9-O-acetylatedsialic acids. Of the various 9-O-acetylated gangliosides detected,one had the characteristics of 9-O-acetylated G^D3. The identificationof 9-O-acetylated sialic acids on distinct glycoproteins andglycolipids should be helpful in assigning a physiological roleto this sugar. O-acetylation gangliosides influenza C virus lymphocytes sialic acids     

鱼类寄生毛细科线虫－新属新种的研究

作者在武陵山地区的鱼类寄生线虫调查工作中,发现一种毛细线虫,经研究,为一新种,定名为岁新毛细线虫,新种（Ｎｅｏｃａｐｉｌｌａｒｉａｐｈｏｘｉｎｉｓｐ．ｎｏｖ．）。根据其特征,为此建立一新属──新毛细线虫属。     

红旗泡水生植物群落结构与功能的研究

红旗泡是松嫩平原上的水草型湖泊,１９７２年由引嫩干渠补入嫩江水,使其成为大庆市主要水源地和渔业基地。该湖水生植被分布面积大,覆盖近１／２的水面。本文分析了芦苇,狭叶香蒲和稗等单优群落的结构与分布,并统计了混合群落的数量特征。随着油田开发,大庆地区的水体均受到不同程度的污染;因红旗泡水生植物资源丰富且其具清除油污、吸附重金属和沉降悬浮物等净化功能,故使其成为大庆地区水质最好和鱼产量最高的湖泊。     

武陵山地区鱼类寄生杆咽属线虫两新种

本文报道在武陵山地区的白甲鱼［（Ｖａｒｉｃｏｒｋｉｎｕｓ（Ｏｎｙｃｈｏｓｔｏｍａ）ｓｉｍｕｓ（ＳａｕｖａｇｅｅｔＤａｂｒｙ）］和沪溪直口峻（ＲｅｃｔｏｒｉｓｌｕｘｉｅｎｓｉｓＷｕｅｔＹａｏ）中发现的两种杆咽属（Ｒｈａｂｄｏｃｈｏｎａ）线虫新种,定名为白甲鱼杆咽线虫,新种（ＲｈａｂｄＯｃｈｏｎａｏｎｙｒｋｏｓｔｏｍｉｓｐ．ｎｏｖ．）和短咽杆咽线虫,新种（ＲｈａｂｄＯｃｈｏｎａｂｒｅｖｉｃｈｏｎａｓｐ．ｎｏｖ．）,并对两新种进行了测量和详细的描述。     

Oxidative mechanisms involved in kainate-induced cytotoxicity in cortical neurons

In our previous experiments, evidence of free radical formation has been demonstrated in gerbil brain after kainic acid (KA) administration. In the present study, the mechanisms involved in KA-induced free radical formation and subsequent cell degeneration were investigated using high density cortical neuron cultures. A free radical trapping agent,a-phenyl-N-tert-butyl-nitrone (PBN), as well as the combined action of superoxide dismutase and catalase attenuated KA neurotoxic effect. Calpain-induced xanthine oxidase (XO) activation may play an important role in KA excitotoxicity since calpain inhibitor I as well as allopurinol, a selective XO inhibitor, significantly protected the cortical neurons from KA-induced cell death. However, XO activation may not be the only source producing free radicals, other free radical generating systems such as nitric oxide synphase may also play a role in KA insult.     

高粱蚜灰色灾变长期预测模型

本文应用灰色系统灾变预测理论建立了吕梁地区高粱蚜发生量预测模型．