新城疫病毒非编码序列的遗传演化趋势

【目的】探讨新城疫病毒全基因序列中非编码序列的分子演化规律。【方法】结合本研究室2012年自产蛋下降鸭群中分离测序的一株鸭源新城疫病毒全序列,从GenBank下载35株不同基因型新城疫病毒全长cDNA序列,获取非编码序列,分别绘制引导序列、尾随序列、F-HN及HN-L基因间隔序列(IGS)的遗传进化树,比较编码基因内5’及3’UTR序列核苷酸序列替代特点。【结果】非编码序列的长度及位置高度保守,而其核苷酸基因序列在不断发生变异,且变异趋势与编码基因序列相一致。【结论】新城疫病毒在整个基因组上编码和非编码序列同步发生变异。     

The relationship between human cytomegalovirus infection and atherosclerosis development

Transport characteristics of essential trace elements as zinc, copper, selenium and iron have been studied in maternal–fetal direction in normal pregnancies, using in vitro perfusion of human placental lobules. Solutions of trace elements corresponding to twice the physiological concentrations were injected (100 l bolus) into the maternal arterial perfusate. Serial perfusate samples were collected every 30 sec from venous outflows for a study period of 5 min. Concentrations of these trace elements and their transport kinetics were determined. Transport fractions (TF) of zinc, copper, selenium and iron averaged 0.21, 0.49, 0.55 and 0.10% of maternal load respectively. Other parameters such as area under the curve, clearance, elimination constant, absorption and elimination rates showed some significant differences between the various elements. Copper and selenium appear to be transported passively in maternal–fetal direction, while for iron and zinc, role of active transport for transfer across the human placental membrane cannot be discounted. We speculate that alterations in copper: zinc TR50 (transport rate for 50% efflux) and TF ratios could serve as useful indicators for assessing placental transport status of these essential elements in complicated pregnancy states.     

Manganese and Arsenic Oxidation Performance of Bacterium-Yunotaki 86 (BY86) from Hokkaido,Japan, and the Bacterium's Phylogeny

We examined the Mn(II) oxidation performance of a bacterium, BY86, collected at Yunotaki Falls Hokkaido, Japan. The bacterium showed rapid oxidation of Mn(II), and brown precipitates containing Mn formed within a few days of incubation. The presence of higher oxidation states of Mn than Mn(II) was ascertained by the UV-vis and XANES sutdy. This bacterium did not oxidize As(III) to As(V) in the absence of Mn. In the presence of Mn, however, As(III) was rapidly oxidized to As(V) on the cell surfaces. These findings indicate that BY86 does not have the ability to directly oxidize As(III) to As(V) within a short period of contact, but indirectly oxidizes it by the Mn oxides generated on the cell surfaces. A phylogenetical study disclosed that BY86 was most closely related to Bacillus cereus with an identity of 99.90%. It is expected that our findings in this study will contribute to the study of Mn(II)-oxidizing bacteria, which play an important role in the biogeochemical cycling of Mn as well as other trace elements including As.     

稻小秆蝇触角感受器的超微结构研究

采用扫描电子显微镜对稻小秆蝇触角感受器进行了观察和研究,结果表明,稻小秆蝇触角上共存在5种感受器,分别为毛形感受器、刚毛型感受器、柱形感受器、锥形感受器蒲姆氏鬃。对各种触角感受器的形态、分布特点进行了描述,并对其功能进行了一定的探讨。     

The iron-sulfur clusters in the two related forms of mitochondrial NADH: ubiquinone oxidoreductase made by Neurospora crassa.

Two related forms of the respiratory-chain complex, NADH: ubiquinone oxidoreductase (Complex I) are synthesized in the mitochondria of Neurospora crassa. Normally growing cells make a large, piericidin-A-sensitive form, which consists of some 23 different nuclear- and 6-7 mitochondrially encoded subunits. Cells grown in the presence of chloramphenicol make a small, piericidin-A-insensitive form which consists of only approximately 13 nuclear-encoded subunits. The subunits of the small form are either identical or similar to nuclear-encoded subunits of the large form. The iron-sulfur clusters in these two forms of Complex I are characterized by redox potentiometry and EPR spectroscopy. The large form of Complex I contains four EPR-detectable iron-sulfur clusters, N1, N2, N3 and N4, with the spin concentration of the individual clusters equivalent to the flavin concentration, similar to the mammalian counterparts. The small Complex I contains clusters N1, N3 and N4, but it is devoid of cluster N2. A model of the electron-transfer route through the large form of Complex I has been derived from these findings and an evolutionary pathway which leads to the emergence of large Complex I is discussed.     

Biodecolourization of azo and triphenylmethane dyes by <Emphasis Type="Italic">Dichomitus squalens</Emphasis> and <Emphasis Type="Italic">Phlebia</Emphasis> spp

Nine white-rot fungal strains were screened for biodecolourization of brilliant green, cresol red, crystal violet, congo red and orange II. Dichomitus squalens, Phlebia fascicularia and P. floridensis decolourized all of the dyes on solid agar medium and possessed better decolourization ability than Phanerochaete chrysosporium when tested in nitrogen-limited broth medium. Journal of Industrial Microbiology & Biotechnology (2002) 28, 201–203 DOI: 10.1038/sj/jim/7000222 Received 12 July 2001/ Accepted in revised form 22 October 2001     

水稻叶绿素合成缺陷突变体及其生物学研究进展

叶绿素是植物叶绿体内参与光合作用的重要色素,叶绿素合成缺陷突变是一类明显的性状突变,其在理论研究和实际应用方面均具有重要的意义。本文介绍了国内外在水稻叶绿素合成缺陷突变体的发掘、作用机理及其基因定位等方面的研究进展。     

Spatio-temporal tumour model for analysis and mechanism of action of intracellular drug accumulation

We have developed a one-dimensional tumour simulator to describe the biodistribution of chemotherapeutic drugs to a tumoral lesion and the tumour cell’s response to therapy. A three-compartment model is used for drug dynamics within the tumour. The first compartment represents the extracellular space in which cells move, the second corresponds to the intracellular fluid space (including cell membrane) which is in direct equilibrium with the extracellular space, and the third is a non-exchangeable compartment that represents sequestered drug which is trapped in the nucleus to damage the cellular DNA, directly triggering cell death. Analytical and numerical techniques (Finite Element Method) are used to describe the tumour’s response to therapy and the effect of parameter variation on the drug concentration profiles in the three compartments.