Effects of 2,5-Dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB) on Light Induced and Glycolytic Phosphate Uptake in Scenedesmus

The effects of DBMIB on photophosphorylation and glycolysis in Scenedesmus obtusiusculus Chod. were investigated by measuring the uptake of inorganic phosphate. To analyze the effects of DBMIB on the different energy coupling possibilities in open chain and cyclic photophosphorylation, DBMIB was given to the algae in narrow concentration intervals between 10^?6M to 10^?4M, either alone, or in combination with DCMU (3-(3,4-dichlorophenyl)-1,1-dimethylurea) or desaspidin. DBMIB inhibits non-cyclic as well as cyclic photophosphorylation in Scenedesmus. However, the DCMU resistant photophosphorylation reactions are less sensitive to DBMIB than the open chain photophosphorylating system in non-DCMU treated cells. Low concentrations of DBMIB even released a part of the DCMU inhibition. Experiments with combinations of DBMIB and desaspidin also indicated that cyclic photophosphorylation is less sensitive to DBMIB than non-cyclic. The inhibition of DCMU resistant cyclic phosphorylation by DBMIB, which is a competitive inhibitor of quinones, indicated a participation of plastoquinones in this type of energy coupling as well as in the non-cyclic and DCMU-sensitive processes. The cyclic and the non-cyclic photophosphorylation pathways probably use different parts of the plastoquinone pool. For the purpose of the experiments, it was necessary to produce data for the effect of DBMIB (10^?6–10^?4M) on glycolysis. The highest concentration gave 50% inhibition.     

Changes in Chloroplast Lipids during the Development of Photosynthetic Activity in Barley Etio-Chloroplasts

The content of monogalactosyl diglyceride, digalactosyl diglyceride, sulfoquinovosyl diglyceride and phosphatidyl glycerol of gel-filtrated etio-chloroplasts isolated from greening barley seedlings was determined. The development of photosynthetic electron transport, measured as anthraquinone autooxidation, was simultaneously determined with an oxygen electrode. During the first hour of irradiation of the etiolated seedlings the lipid content of the plastids decreased rapidly. The decrease is interpreted as a chlorophyll sensitized photooxidation of the fatty acids of the diglycerides. With artificial electron donors an oxygen uptake was detected after 10 min of greening. With no donors added, a DCMU sensitive oxygen uptake was detected after 2 h. The level of DCMU inhibition increased as the plastid developed and total inhibition was obtained after 5 h. Between 2 and 6 h of greening the lipid content of the plastids stayed constant. During this greening period there was a correlation between the appearance of a DCMU sensitive electron transport and the accumulation of the trans-3-hexadecenoic acid of phosphatidyl glycerol. The trans-3-hexadecenoic acid was present already in the dark-grown seedlings but an increase in content did not occur until after 3 h. The lipid content increased after 6 h of greening. This increase coincided well in time with the formation of grana. The fatty acid composition of the individual lipids, with the exception of phosphatidyl glycerol, and the monogalactosyl diglyceride to digalactosyl diglyceride ratios did not change fundamentally during the greening.     

利用RNAi技术分析VP16对HSV-1增殖过程的影响

目的:探讨在RNAi技术条件下,HSV-1感染Vero细胞过程中,病毒间层蛋白VP16的生物学功能。方法:用T7RNA聚合酶体外合成针对VP16 mRNA的3种T7siRNAs。用Lipofectamine 2000脂质体转染Vero细胞后接种HSV-1,感染后12、24、36、48、60和72h,分别收取实验组和对照组标本,Karber法计算病毒滴度值,绘制子代病毒一步生长曲线。结果:病毒子代一步生长曲线显示,转染siRNAs的实验组Vero细胞接种HSV-1后24h(24h pi),病毒滴度明显低于对照组;12h pi也观察到病毒滴度低于对照组的现象;siRNAs具有协同作用,三种siRNAs同时作用时干扰效果最为明显;实验组病毒滴度高峰出现时间后移12h左右。结论:HSV-1间层蛋白VP16对病毒复制、成熟起重要的生物学作用。     

Response of subterranean clover (Trifolium subterraneum) to ozone in relation to plant age and light conditions during exposure

Potted subterranean clover ( Trifolium subterraneum ) plants of different ages were exposed to 70 nl l⁻¹ ozone for 6 h, either during the light or during the dark period in a laboratory-based climate chamber. There was limited visible leaf injury on plants which were 14–20 and 28–34 d old and no significant decrease in biomass after daytime ozone exposure. The oldest leaves of 22–26 d old plants exhibited severe visible injury, which was associated with a significant reduction in biomass in 24–26 d old plants. Thus, ozone-induced visible injury of different magnitude developed in all plants, but was associated with biomass reduction only during a limited period of the plant's life-span. Apart from modifying ozone uptake by plants, climatic conditions are important as growth modifiers. It is suggested that subterranean clover plants of defined developmental stages should be used in bioindication of ozone. Night ozone exposure injured significantly fewer leaves than day exposure. However, some leaves developed visible injury even after night ozone exposure. Night uptake of ozone may be of more importance in northern than in central and southern Europe, because summer nights are short and, for a certain period, never completely dark.     

ADP, AMP and Pi interactions with a (Na++ K++ Mg2+)-dependent ATPase in sugar beet roots

Continuous measurements of CO₂-release from intact roots of Lolium multiflorum growing in nutrient solution were carried out during 3–7 weeks. Periods of days with high level of irradiance and periods with low level alternated. Root respiration rate was found to depend on photosynthesis. The change in root respiration, induced by change in photosynthesis, was delayed. The root respiration rate showed diurnal fluctuations with two characteristic peaks occurring 4–6 and 14–16 hours after onset of the photoperiod. The amplitudes increased with increasing photosynthesis. The frequencies were independent of the length of photoperiod, when this varied between 8 and 16 hours. The fluctuations are discussed in relation to diurnal fluctuations in protein synthesis.     

基于第二代测序技术兰州鲇线粒体基因组全序列测定与分析

研究采用高通量第二代测序技术,构建获得兰州鲇（Silurus lanzhouensis）线粒体基因组全序列,并对全序列特征和结构进行了分析。研究结果表明,兰州鲇线粒体基因组全序列长度为16523 bp,碱基组成具有高A+T低G+C含量的偏向性,具有脊椎动物典型的结构组成。13个PCG基因中存在2种启动子（ATG、GTG）、3种终止子（TAG、TAA和T或TA）。除tRNA-Ser（AGN）基因二级结构中DHU臂缺失,其余21个tRNA基因可折叠成典型三叶草结构。12S rRNA二级结构由45个茎环结构组成4个结构域,16S rRNA由54个茎环结构组成6个结构域。含有关键序列标签的控制区（CR）可分为3个不同的结构域:终止序列区（TAS1、TAS2）、中央保守区（CSB-F、CSB-E和CSB-D）和保守序列区（CSB1、CSB2和CSB3）。非编码区含有一段保守的控制轻链复制起始的序列区（O_L）。基于线粒体基因组全序列和通用标签COX1基因标记可区分兰州鲇同其他鲇形目鱼类种质进化关系。     

The Appearance and Development of Photosynthetic Activity in Etiolated Barley Leaves and Isolated Etio-chloroplasts

The appearance and development of the oxygen exchanging capacity of greening barley leaves were measured using a manometric technique and an oxygen race electrode. An oxygen evolution could first be detected after one hour of greening. During the first hour of greening a light-dependent oxygen uptake was observed. The oxygen evolving capacity, calculated on a chlorophyll weight basis, showed a fast rise in activity during the first hours of greening. A maximal activity was reached after 5 to 10 hours of greening; the oxygen evolution then declined. Using oxygen electrodes different aspects of the electron transport in etio-chloroplasts prepared from the greening barley leaves were also investigated. The activity in photosystem I and II, as well as the cooperation between the two photosystems, were studied by measuring the oxygen exchange from the etio-chloroplasts in the absence and presence of added oxidants and reductants. An activity in photosystem I could be detected already after 5 minutes of greening. The activity of photosystem I, when calculated on a chlorophyll basis, had the same appearance as the oxygen evolution from the intact plant material. An activity in photosystem II and a cooperation between the two photosystems were first detected after 3 hours of greening. After about 15 hours of greening a cooperation corresponding to that from chloroplasts prepared from normal green leaves was observed.     

免疫细胞在棕色脂肪产热及白色脂肪棕色化过程中的功能研究进展

肥胖已经成为威胁人类健康的全球性问题,棕色脂肪(Brown adipose tissue,BAT)及米色脂肪因其能够通过产热作用增加能量消耗这一特性,已成为一种备受关注的潜在肥胖治疗方法。近年来的研究发现M2型巨噬细胞(Alternatively activated macrophages,M2 type)能够促进BAT产热和白色脂肪(White adipose tissue,WAT)的棕色化(即米色脂肪的形成过程),但随后的一些研究却得到了相反的结论。到目前为止,M2型巨噬细胞是否参与促进WAT的棕色化过程仍是一个备受争议的话题。主要对M2型巨噬细胞、II型固有淋巴细胞(Type 2 Innate Lymphoid Cells,ILC2s)和嗜酸性粒细胞(Eosinophils)对BAT产热和WAT的棕色化的促进作用,以及M2型巨噬细胞不参与/抑制WAT棕色化这两个方面的研究状况做一综述。     

甘肃子午岭区野猪主要内脏器官的测量及消化机能

近年来,驯养野猪已成为湖南、湖北、河南等地发展特种经济动物的一大热点项目(王京仁和李淑红,2001).与此同时,虽然对野猪的研究内容涉及到其食性、遗传特性及其杂交利用效果等方面(兰宏等,1995;蒋思文等,2001; 刘娣等,2003;王文等,2005;鲁庆彬等, 2007),但对野猪内脏器官和消化能力的研究相对较少,仅见Conklin等(1994)、Uhr(1995)和宋青龙(2004)的报道,且研究结果不尽相同. Uhr(1995)对野猪消化道研究表明,野猪消化能力、消化道容积、长度均显著小于家猪,而宋青龙(2004)研究则表明,野猪小肠相对重、相对长度以及大肠的相对长度均显著高于家猪,这种差异可能是野猪亚种不同所致.本文以甘肃子午岭区的土种猪棗八眉猪为对照,对甘肃子午岭区野猪内脏器官结构及其消化机能进行研究,对进一步了解不同地区野猪生理特点,依据消化器官的差异制定甘肃子午岭区野猪饲养管理规程,合理配制日粮,科学饲喂,提高该地区野猪驯养成活率将具有实际意义.