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1.
硬头鳟幼鱼部分形态性状和体重的关系   总被引:4,自引:0,他引:4       下载免费PDF全文
随机选取116尾硬头鳟(Oncorhynchus mykiss)幼鱼,测量其体长、体高、体厚、头长、眼径和眼间距、体重7个性状,计算各性状间的相关系数,采用通径分析方法计算以表型形态性状为自变量对体重作因变量的通径系数、决定系数及复相关指数,对各性状的影响大小进行剖析,明确影响硬头鳟幼鱼体重的主要外部形态性状,为硬头鳟选育提供理论依据和理想的测度指标。结果表明,所测各表型性状与体重之间的相关系数均达到极显著水平(P<0.01);体高对体重的直接影响(0.363)最大,其次分别为体长(0.291)、体厚(0.264)和眼径(0.111)。所选性状对体重的复相关指数R2=0.972,表明所选性状是影响体重的主要性状。利用逐步回归分析方法建立以体长、体高、体厚和眼径为自变量估计体重的多元回归方程为:y=-107.53+3.03 X1+20.01 X3+12.63 X2+45.56 X5。  相似文献
2.
温度和摄食对溪红点鲑幼鱼呼吸代谢的影响   总被引:3,自引:0,他引:3       下载免费PDF全文
在不同水温[(5.5±0.5) ℃、(8.5±0.5) ℃、(11.5±0.5) ℃、(14.5±0.5) ℃、(17.5±0.) ℃]条件下,分别测定了饱食和空腹状态下溪红点鲑幼鱼的耗氧率和排
氨率,分析了温度和摄食对溪红点鲑幼鱼呼吸代谢的影响.结果表明:饱食后,5个温度梯度组溪红点鲑幼鱼的耗氧率和排氨率均迅速上升,达最大值后缓慢下降,并逐渐恢复到初始水平;饱食状态下,溪红点鲑幼鱼耗氧率(OR)和排氨率(NR)与温度(t)的回归方程分别为OR=-0.0601t4+2.5542t3-39.256t2+276.26t-598.75(n=650,R2=1,4.5 ℃4+0.0826t3-1.2318t2+8.6186t-18.838(n=650,R2=1,4.5 ℃0.9738(n=650,R2=0.9974,4.5 ℃1.0896(
n=650,R2=0.9977,4.5 ℃相似文献
3.
五种鲟鱼线粒体控制区异质性和系统发育分析   总被引:3,自引:0,他引:3       下载免费PDF全文
利用保守引物得到五种鲟鱼的线粒体DNA(mtDNA)控制区(D-loop)全长,长度在795~813 bp。序列中包括了CBS(conserved sequence block)和TAS(termination-associated sequence)区域。利用最大似然法、最大简约法和贝叶斯法构建了系统发育树,发育树分成两枝,呈现明显的生物地理分布。分析表明,现有的鳇属鱼类不是单系群起源。五种鲟鱼D-loop序列都存在长度和数目不等串联重复序列,长度在78~82 bp之间,重复序列拷贝数在4~6次不等,因此造成了mtDNA广泛的异质性现象。不同种类的重复序列单元十分相似,达氏鳇和史氏鲟重复序列单元相似度为82.93%,西伯利亚鲟和俄罗斯鲟重复序列单元相似度为90.59%。在串联重复序列后是一段不完全重复序列。通过与已有同种的重复序列比对发现不同鲟鱼重复序列相同,不同地理区域相同物种的重复序列可能发生过分子内重组。这些表明重复序列在鲟鱼进化上具有相关意义,推测重复序列可能产生在种分化前,重组发生在种分化后。  相似文献
4.
硬头鳟为大麻哈鱼属,原产于美国阿拉斯加的Kuskokwin河和加拿大不列颠哥伦比亚省的和平河等水域,为洄游性、广盐性冷水鱼类,在淡水至盐度为10‰的水体中均可良好生存和生长,可生存在水温0—22℃的水域环境中,最适生长水温10—18℃,是欧美诸国游钓的主要对象之一。由于基因工程和驯化手段不断完善,硬头鳟可以在淡水中集约化养殖。其生长速度、肉味肉质、抗病力、适应力均超过野生和养殖的同科其他鱼类,15个月生长期,体重可达2 kg。近年来硬头鳟自然产量逐年降  相似文献
5.
一种基于温敏质粒的新型基因敲除方法   总被引:1,自引:0,他引:1       下载免费PDF全文
基于温敏型质粒而不用线性DNA的方法用于快速敲除沙门氏菌染色体上的目的基因。以伤寒沙门氏菌S.ty2基因组为模板扩增得到的ssaV基因的上下游同源臂,与两端带有FRT位点的卡那霉素抗性基因片段连接到温敏型质粒pHY304,共同构建同源重组载体;然后转化S.ty2,通过筛选得到带有抗性标记的重组菌。通过转入重组酶表达质粒pCP20,去除抗性标记,得到ssaV基因缺失的重组菌,并在 DNA 水平进行了鉴定。建立了一种改进的基于温敏质粒的沙门氏菌的基因敲除方法,此方法也值得在其他革兰氏阴性菌的基因敲除中尝试应用。  相似文献
6.
Microtubules, actin filaments, and Golgi apparatus are connected both directly and indirectly, but it is manifested differently depending on the cell organization and specialization, and these connections are considered in many original studies and reviews. In this review we would like to discuss what underlies differences in the structural organization of the Golgi apparatus in animal and plant cells: specific features of the microtubule cytoskeleton organization, the use of different cytoskeleton components for Golgi apparatus movement and maintenance of its integrity, or specific features of synthetic and secretory processes. We suppose that a dispersed state of the Golgi apparatus in higher plant cells cannot be explained only by specific features of the microtubule system organization and by the absence of centrosome as an active center of their organization because the Golgi apparatus is organized similarly in the cells of other organisms that possess the centrosome and centrosomal microtubules. One of the key factors determining the Golgi apparatus state in plant cells is the functional uniformity or functional specialization of stacks. The functional specialization does not suggest the joining of the stacks to form a ribbon; therefore, the disperse state of the Golgi apparatus needs to be supported, but it also can exist “by default”. We believe that the dispersed state of the Golgi apparatus in plants is supported, on one hand, by dynamic connections of the Golgi apparatus stacks with the actin filament system and, on the other hand, with the endoplasmic reticulum exit sites distributed throughout the endoplasmic reticulum.  相似文献
7.
Zhang F  Liao L  Ju Y  Song A  Liu Y 《Neurochemical research》2011,36(10):1903-1909
Nitric oxide (NO) participates in the neural pathways controlling the lower urinary tract (LUT). Expression of NO synthase (NOS) can be upregulated after spinal cord injury (SCI), and altered NOS activity may participate in resulting LUT dysfunction. To investigate distribution of NOS-immunoreactivity (NOS-IR) in neurons of rats following SCI and the possible effects of NOS inhibitors. Expression of neuronal and inducible NOS-IR in lumbosacral spinal cord was assessed in rats. Cystometry was performed to examine effects of intrathecal injection of NOS inhibitor. There was increased expression of neuronal NOS-IR after trauma. Maximum bladder capacity was increased by neuronal NOS (nNOS) inhibitors. Upregulation of nNOS may facilitate emergence of the spinal micturition reflex following SCI; nNOS inhibitor suppressed SCI-induced urinary incontinence by increasing bladder capacity. Our results indicate manipulation of NO production could help treat LUT dysfunction after SCI.  相似文献
8.
魏杰  赵文  李文通  张黎  殷旭旺 《生物学杂志》2012,29(2):18-21,46
研究了3种微生态制剂(复合微生态制剂Ⅰ、复合微生态制剂Ⅱ和芽孢杆菌)对大型溞的急、慢性毒性影响,分析比较了3种微生态制剂的安全使用剂量以及对大型溞生殖和种群增长的影响.试验结果表明,3种微生态制剂对大型溞死亡率影响均显著(P < 0.05),从安全浓度来看,对大型溞的毒性作用依次为:复合微生态制剂Ⅱ>复合微生态制剂Ⅰ>芽孢杆菌;在安全浓度范围内,3种微生态制剂对大型溞亲代(P)的生殖和种群增长均有明显的促进作用,表现在随微生态制剂浓度的升高,P代的净生殖率(R0)和内禀增长率(rm)均显著增加(P < 0.05),其中以复合微生态制剂Ⅰ的效果最好,R0最高值为对照组的7倍,rm最高值为对照组的1.7倍;3种微生态制剂对大型溞子一代(F1)和子二代(F2)的生殖和种群增长均没有促进作用.  相似文献
9.
Extracellular antigen 1 (EA1), a major component of the Bacillus anthracis surface layer (S-layer), was used as a fusion partner for the expression of heterologous antigen. A recombinant B. anthracis strain was constructed by integrating a translational fusion harboring the DNA fragments encoding the cell wall–targeting domain of the S-layer protein EA1 and the 20-kDa N-terminal fragment of anthrax protective antigen (PA20) into the chromosome. A thermosensitive plasmid expressing Cre recombinase was introduced at a permissive temperature to remove the antibiotic marker. Cre recombinase action at the loxP sites excised the spectinomycin resistance cassette. The final derivative strains were analyzed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis, Western blot analysis, and immunofluorescence analysis. PA20 was successfully expressed on the S-layer of the recombinant antibiotic marker-free strain. Guinea pigs were immunized with the attenuated recombinant B. anthracis strain, and the bacilli elicited a humoral response to PA20. This antibiotic marker-free strain and the correlative experiment method may have potential applications for the generation of a live attenuated anthrax vaccine.  相似文献
10.
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