银鲫复合种外源遗传物质整入的RAPD分析

在优化RAPD检测条件的基础上，采用40对随机引物，比较分析了银鲫复合种、异育银鲫和兴国红鲤相互间扩增DNA片段的异同性。总的来说，银鲫复合种和异育银鲫具有基本一致的扩增产物，而与兴国红鲤的扩增产物多数不同。相似率分析表明，银鲫复合种与兴国红鲤之间的相似率为31.6％，异育银鲫与兴国红鲤之间的相似率为28．6％。在分析中，除发现银鲫复合种、异育银鲫与兴国红鲤间共有的扩增片段外，还发现了银鲫复合种与兴国红鲤间共有的扩增片段以及银鲫复合种所特有的DNA扩增带。本研究不但为银鲫复合种异源遗传成分的整人提供了新的

鲤科鱼类6个正反交人工异源三倍体胚胎的染色体变化及其发育命运

采用静水压休克保留第二极体的方法,在鲤(♀)×鲢(?)、鲫(♀)×鲢(?)、白鲫(♀)×鲢(?)和鲢(♀)×鲤(?)、鲢(♀)×鲫(?)、鲢(♀)×白鲫(?)6个正反交组合中都诱导出了异源三倍体,但只有正交鲤(♀)×鲢(?)、鲫(♀)×鲢(?)和白鲫(♀)×鲢(?)3个处理组中整倍性的异源三倍体胚胎才有可能正常发育,孵化出苗;而反交鲢(♀)×鲤(?)、鲢(♀)×鲫(?)和鲢(♀)×白鲫(?)3个处理组中的异源三倍体胚胎在发育过程中不断发生染色体排除和丢失,形成非整倍体而死亡,只有少数雌核发育二倍体鲢才能孵

果糖1,6-二磷酸酯酶的代谢调控

<正> 果糖1,6-二磷酸酯酶(FBPase 1)在生物体内糖异生代谢途径中起着重要的作用。当二价金属离子存在时,它催化果糖1,6-二磷酸(Fru-1,6-P_2)水解生成果糖6-磷酸(Fru-6-P)和无机磷。它是一个由4个相同亚单位构成的蛋白质,其亚单位分子量约为35 000～40 000。FBPase 1可被蛋白水解酶降解修饰,使其最适pH从7.5变为9.2。该酶受AMP及果糖2,6-二磷酸(Fru-2,6-P_2)

Waterborne exposure to fluorotelomer alcohol 6:2 FTOH alters plasma sex hormone and gene transcription in the hypothalamic-pituitary-gonadal (HPG) axis of zebrafish

Fluorotelomer alcohols (FTOHs) have shown estrogenic activity in vitro and in vivo, but the mechanism of this activity is not known. In this study, 18-week-old zebrafish (Danio rerio) were exposed to 0, 0.03, 0.3 and 3.0 mg/l 1H, 1H, 2H, 2H-perfluorooctan-1-ol (6:2 ETCH) for 7 days, and the effects on plasma sex hormone levels were measured followed by use of real-time PCR to examine selected gene expression in hypothalamic-pituitary-gonadal (HPG) axis and liver. Exposure to 6:2 FTOH significantly increased plasma estradiol (E2) and testosterone (T) levels in both males and females. Furthermore, the ratio of T/E2 was reduced in females while increased in males. In females, the increase of E2 was accompanied by up-regulated hepatic estrogenic receptor alpha (ER alpha) and vitellogenin (VTG1 and VTG3) expression. In males, the elevation of the T level is consistent with the up-regulation of cytochrome P450 c17 alpha-hydroxylase, 17, 20-lase (CYP17) and the down-regulation of cytochrome P450 aromatase A (CYP19A). The present study demonstrated that waterborne exposure to 6:2 FTOH alter plasma sex hormone levels and the ratio of T/E2, as well as the transcriptional profiles of some genes in the HPG axis and liver. The results suggested that FTOHs may disturb fish reproduction through endocrine disrupted activity. (C) 2009 Elsevier B.V. All rights reserved.

Design and performance analysis of a 6 MW medium-speed Brushless DFIG

The paper presents the design and performance analysis of a 6 MW medium-speed Brushless Doubly-Fed Induction Generation (Brushless DFIG) for a wind turbine drivetrain. Two machines with different frame sizes have been designed to show the flexibility of the design procedure. The mediumspeed Brushless DFIG in combination with a two stage gearbox offers a low-cost, low-maintenance and reliable drivetrain for wind turbine applications.

A trapped field of 17.6 T in melt-processed, bulk Gd-Ba-Cu-O reinforced with shrink-fit steel

The ability of large-grain (RE)Ba2Cu3O7-δ ((RE)BCO; RE = rare earth) bulk superconductors to trap magnetic fields is determined by their critical current. With high trapped fields, however, bulk samples are subject to a relatively large Lorentz force, and their performance is limited primarily by their tensile strength. Consequently, sample reinforcement is the key to performance improvement in these technologically important materials. In this work, we report a trapped field of 17.6 T, the largest reported to date, in a stack of two silver-doped GdBCO superconducting bulk samples, each 25 mm in diameter, fabricated by top-seeded melt growth and reinforced with shrink-fit stainless steel. This sample preparation technique has the advantage of being relatively straightforward and inexpensive to implement, and offers the prospect of easy access to portable, high magnetic fields without any requirement for a sustaining current source. © 2014 IOP Publishing Ltd.

PCR-RFLP analysis of mitochondrial DNA ND5/6 region among 3 subspecies of common carp (Cyprinus carpio L.) and its application to genetic discrimination of subspecies

Mitochondrial DNA ND5/6 region was studied by PCR-RFLP analysis among ten representative strains belonging to three subspecies (Cyprinus carpio carpio, Cyprinus carpio haematopterus and Cyprinus carpio rubrofuscus) of common carp (Cyprinus carpio L.). A total of 2.4 kb fragment was amplified and subjected to restriction endonuclease analysis with nine restriction endonucleases subsequently. The results indicated that each subspecies owned one hyplotype and four restriction enzymes (Dde I, HaeIII, Taq I and Mbo I) produced diagnostic restriction sites which could be used for discriminating the three subspecies and as molecular genetic markers for assistant selective breeding of common carp.

Isolation by phage display and characterization of a single-chain antibody specific for O-6-methyldeoxyguanosine

New approaches of making single chain Fv antibodies against O-6-methyl-2'-deoxyguanosine (O(6)MdG) have been demonstrated by using the phage antibody display system. Using O(6)MdG as an antigen, 21 positive clones were identified by ELISA from this library, one of which, designated H3, specifically binds to O(6)MdG with high affinity. The H3 scFv antibody has an affinity constant (K-aff) of 5.94 x 10(11)(mol/L)(-1). H3 scFv has been successfully used to detect O-6 MdG in DNA hydrolyses from yeast or E. coli cells treated with a DNA methylating agent. To our knowledge, this is the first report of the selection of a specific scFv against DNA adducts. The results demonstrate the potential applications of the phage display technology for the detection of DNA lesions caused by mutagens and carcinogens.

Fabrication of ultra-low density and long-wavelength emission InAs quantum dots

By optimizing the molecular beam epitaxy growth conditions of self-organized InAs/GaAs quantum dots (QDs), we obtained an ultra-low density system of InAs QDs (4 x 10(6)cm(-2)). Photoluminescence (PL) spectroscopy reveals the emission wavelength at room temperature to be longer than 1300 nm with a GaAs capping layer. (c) 2007 Elsevier B.V. All rights reserved.