4龄中华鲟垂体的EST分析(英文)

表达序列标签(Expressed sequencetag,EST)是鉴定基因表达规律和发现新基因的一种有效的分子生物学手段。为了能在中华鲟(Acipenser sinensis Gray)中发现与生长和生殖内分泌调控相关的基因,我们构建了中华鲟垂体的SMARTcDNA质粒文库。垂体是调节生长和生殖内分泌的重要器官。在本研究中,通过测序筛选得到了944个EST克隆,将所得EST与GenBank数据库中的序列进行比对,结果表明,802(84.96%)个克隆可以找到同源序列,共代表461个基因,其中含132个已

中国水华蓝藻的新记录属——拟浮丝藻属(Planktothricoides)

在近年来对水华蓝藻的调查中,确定了我国一水华蓝藻新记录属——拟浮丝藻属Planktothricoides(WoIoszyńska) Suda et Watanabe 2002。文中对该属及该属一个新记录种的主要形态学特征进行了描述,并对其相近属浮丝藻属Planktothrix进行了形态学比较研究。

斜带石斑鱼囊胚期胚胎和尾芽期胚胎差异表达基因的筛选及克隆

以斜带石斑鱼囊胚期胚胎和尾芽期胚胎分别作为检验组和驱动组,构建了石斑鱼囊胚期胚胎和尾芽期胚胎的抑制性差减杂交cDNA文库。以α-tubulin作为检测指标,显示差减效率分别高达28和27。分别取囊胚期胚胎和尾芽期胚胎各192和960个PCR阳性克隆进行斑点杂交,得到15个囊胚期和131个尾芽期的斑点杂交阳性克隆。测序和数据库比对分析表明,囊胚期15个阳性克隆中有11个已知基因的cDNA片段和没有同源性的4个cDNA片段;而在尾芽期的131个阳性克隆中,有123个已知基因的cDNA片段和8个没有同源性的cD

南方某地妇女儿童血液中多氯联苯蓄积水平调查

目的了解我国南方某多氯联苯(PCBs)高暴露地区的妇女、儿童体内PCBs的蓄积水平。方法采集当地某小学中符合条件的50对母子的血液,用GC-MS法进行PCBs含量的测定。结果儿童血液中所测的13种PCBs的浓度最大值为505 ng/g类脂,几何均数为192 ng/g类脂;母亲血液中所测的13种PCBs的总浓度的最大值为461 ng/g类脂,几何均数为176 ng/g类脂;儿童和母亲血液中PCBs含量的相关系数为0.74。结论该地区妇女和儿童血液中检测出较高水平的PCBs,儿童和母亲血液中PCBs含量呈现较

独立思考 敢于创新

刘建康院士是著名的鱼类学家、生态学家。他致力于淡水鱼的生态学研究,取得显著的社会效益和经济效益。他以极大的热情投身到湖北省梁子湖和长江干流的鱼类的生态调查研究,以及东湖渔业生产、生态学的研究,从理论和实践上为我国淡水渔业与淡水生态学的发展作出了贡献。他总结的“重视科学实验,着眼社会实践;不唯上,不唯书,不唯权威;独立思考,敢于创新”的治学格言,令人深受启发。现将他在《科学的道路》发表的“独立思考,敢于创新”一文; 经作者同意,转载于后。

武汉东湖浮游生物群落DNA多态性与富营养化

对武汉东湖不同程度富营养化湖区 ,即站 、站 与站 浮游生物进行了群落级 DNA多态性的 DNA指纹研究 ,并就其拓扑结构与富营养化特征参数之间关系进行了分析。实验结果如下 :(1)各站点总氮、总磷及叶绿素 a分别为 1.14 6～ 2 .2 35mg/ L、0 .0 13～ 0 .2 10 mg/ L 和 4 0 .2 5～ 10 9.2 2 μg/ L;(2 )所筛选的 5个随机引物共获得 2 9个扩增位点 ,其中多态位点占75 .9% ,各引物扩增谱带数在 2～ 6间。站 的扩增条带数最多、谱带多态

复合垂直流构建湿地中有机质积累与基质堵塞

利用灼烧失重研究了复合垂直流构建湿地小试及中试系统中有机质的积累规律及其与湿地基质堵塞的关系,通过示踪剂实验测定了堵塞前后系统水力停留时间的变化.结果表明,有机质主要积累在基质表层和上层0~50mm处且有机质积累主要发生在下行池.有机质含量与基质深度负相关,基质表层有机质含量明显高于其他各层.湿地系统中有机质含量与基质渗透系数呈明显的负相关性,有机质含量越高,基质渗透系数越小,说明有机质积累是导致构建湿地堵塞的一个重要原因.复合垂直流构建湿地堵塞后,其水力特征发生了改变,延长了该系统的实际水力停留时间.

草鱼、中华鳖T淋巴细胞表面抗原的研究

以草鱼脑组织、中华鳖脑组织和胸腺细胞为抗原制备兔抗草鱼脑血清 (RACBS)、兔抗中华鳖脑血清 (RATBS)和兔抗中华鳖胸腺细胞血清 (RATTS)。补体依赖性细胞毒试验和不同组织对RATBS、RATTS的吸收试验结果表明 :中华鳖胸腺细胞和脑组织均存在Thy1抗原(亦称脑组织抗原或胸腺 -脑组织T细胞抗原 ) ;草鱼脑组织缺乏Thy1抗原。应用间接酶标免疫组化染色技术显示 :Thy1抗原阳性反应物沉淀于中华鳖胸腺细胞和外周一部分淋巴细胞表面。进一步用抗人白细胞分化抗原CD4、CD8单克隆抗体进行免疫组

中华鲟(Acipenser sinensis)及相关种类的mtDNA控制区串联重复序列及其进化意义

采用 PCR技术和 DNA测序技术 ,发现了我国一级珍稀保护动物中华鲟 ( Acipensersinensis)线粒体 DNA( mt DNA)的控制区 ( D- loop)存在数目不等的串联重复序列 ,该重复序列造成了中华鲟广泛的异质性现象 .从分子水平进行了不同类型重复序列变化规律的研究 ,同时还初探了重复序列在我国其它几种鲟鱼类的存在情况 ,发现在白鲟 ( Psephurus gladius)、达氏鲟 ( A.dabryanus)和史氏鲟 ( A.schrenckii)均存在类似的重复序列结构 .序

几种农药对固氮蓝藻生长的影响

<正> 在我们进行固氮蓝藻对水稻肥效的田间试验时,就遇到这样的一个问题:施用农药来防治水稻的病虫害对固氮蓝藻的生长繁殖有没有影响?若果施用的农药对固氮蓝藻有毒害作用,那么,要在田间接种繁殖固氮蓝藻作为水稻的氮肥源,便会和防治病虫害发生矛盾,要推广使用固氮蓝藻就会有许多困难了。

Optimum temperature for the growth performance of juvenile orange-spotted grouper (Epinephelus coioides H.)

Effects of water temperature (17, 21, 25, 30 and 35 degrees C) and body size (14.75-281.41 g initial body weight) on food consumption, growth, feed conversion, and dry matter content in orange-spotted grouper fed to satiation were investigated. The combined effect of temperature (T, degrees C) and body weight (W, g) on maximum food consumption (C-max, g/day) was described as: InCmax= -7.411+0.828 lnW+0.317T-0.004 7T(2), and the optimum feeding temperature was 33.9 degrees C. The combined effect of temperature and body weight on growth (G) was described as: InG= -4.461-0.208lnW+0.394T-0.006 3T(2). The optimum growth temperature was 31.4 degrees C, whereas overall growth rates were high at 25, 30 and 35 degrees C. Feed conversion efficiencies (FCE, %), increasing first and then decreasing with increasing temperature, averaged from 1.8 to 2.1 in terms of dry weight of food fish. The optimum temperature for FCE tended to be lower than that for growth or feeding. Dry matter content increased with both increasing water temperature (17, 25, 30 and 35 degrees C) and body weight, and the combined effect of temperature and body weight on dry matter content (DM, %) was described as: lnDM =3.232+0.01 4 lnW-0.004 4T+0.001 2TlnW.

cDNA cloning and characterization of a novel SNX gene differentially expressed in previtellogenic oocytes of gibel carp

To understand the molecular events governing fish oogenesis, a multiple technique was used to identify the genes differentially expressed at different phases during fish oogenesis. This technique is a combination of suppression subtractive hybridization, SMART cDNA synthesis and RACE-PCR. Here we report the cDNA cloning and expression characterization of a novel SNX gene based on its differential transcription between previtellogenic and fully mature oocytes in naturally gynogenetic gibel carp. First, a cDNA fragment selectively expressed in previtellogenic oocytes was identified and used to screen a SMART cDNA library prepared from the same mRNA sample by RACE-PCR for cloning fully length cDNA. The full length cDNA was 1392-bp long and coded for a novel SNX protein with 225 amino acids. The 5' UTR had 72 bp and 3' UTR had 642 bp. Unlike most of maternal genes that are transcribed after vitellogenesis and stored in oocytes, this gene is expressed at a higher level in the previtellogenic oocytes and at a much lower level in fully matured oocytes. However, RT-PCR analysis of tissues showed it was ubiquitous transcription. The novel gene is named fish sorting nexin (fSNX), because it contains a conserved PX domain. The fact which major expression of the gene occurs in the previtellogenic oocytes suggests that it might have an important function in the oogenesis. (C) 2003 Elsevier Inc. All rights reserved.

An experimental study about the influence of well thickness on the electroluminescence of InGaN/GaN multiple quantum wells

The influence of well thickness on the electroluminescence (EL) of InGaN/GaN multiple quantum wells (MQWs) grown by metalorganic chemical vapor deposition is investigated. It is found that the peak wavelength of EL increases with the increase of well thickness when the latter is located in the range of 3.0-5.1 nm. The redshift is mainly attributed to the quantum confined Stark effect (QCSE). As a contrast, it is found that the EL intensity of InGaN/GaN MQWs increases with the increase of well thickness in spite of QCSE. The result of X-ray diffraction demonstrates that the interface become smoother with the increase of well thickness and suggests that the reduced interface roughness can be an important factor leading to the increase of EL intensity of InGaN/GaN MQWs. (C) 2009 Elsevier B.V. All rights reserved.

Mode Simulation for Midinfrared Microsquare Resonators With Sloped Sidewalls and Confined Metals

EQUILATERAL-TRIANGLE; MU-M; LASERS; MICROLASERS; MICRODISK Abstract: Mode characteristics for midinfrared microsquare resonators with sloped sidewalls and confined metal layers are investigated by finite-difference time-domain (FDTD) techniques. For a microsquare with a side length of 10 mu m, the mode quality (Q)-factors of 8329, 4772, and 2053 are obtained for TM5,7 mode at wavelength 7.1 mu m by three-dimensional FDTD simulations, as the tilting angles of the side walls are 90 degrees, 88 degrees, and 86 degrees, respectively. Furthermore, microsquare resonators laterally surrounded by SiO2 and metal layers are investigated by the two-dimensional FDTD technique for the metal layers of Au, Ti-Au, Ag-Au, and Ti-Ag-Au, respectively.