药用植物草珊瑚RAPD扩增条件优化

采用CTAB-DNA提取方法,从草珊瑚植物的嫩叶中提取总DNA。以此DNA为模板,优化了草珊瑚RAPD-PCR的反应条件。结果表明,PCR扩增体系最适宜的条件为:反应体积25μL,内含2.5mmol/L Mg2+、1.0UDNA聚合酶、0.4μmol/L引物、60ng模板DNA和0.16mmol/L dNTP。扩增程序为:94℃预变性2min;94℃变性30s,37℃复性30s,72℃延伸80s,40个循环;72℃延伸10min;4℃保存10min。     

金弹总DNA提取及RAPD体系优化

以金弹叶片为材料, 研究其总DNA提取方法及RAPD-PCR条件.结果表明,用改良CTAB法Ⅱ提取的DNA适于RAPD分析;优化的金弹RAPD-PCR体系为:反应体积20 μl,Mg2+ 2.5 mmol/L、dNTP 0.25 mmol/L、引物0.20 μmol/L、模板DNA 1.0 ng/μl和1 U Taq DNA聚合酶.相应的扩增程序为:94 ℃预变性3 min;94 ℃变性45 s,37 ℃复性60 s,72 ℃延伸120 s,循环45次;72 ℃延伸10 min,4 ℃结束.     

栝楼ISSR-PCR体系的正交优化

目的：建立栝楼最佳ISSR-PCR正交优化体系,为开展栝楼ISSR分子标记奠定技术基础。方法：采用正交试验设计对影响栝楼ISSR-PCR扩增的重要参数（DNA模板、MgCl2、dNTPs、引物、TaqDNA聚合酶）进行优化试验,同时进行不同温度梯度试验和ISSR体系筛选。结果：最佳的栝楼ISSR-PCR的反应体系（20μl）为：30ng模板DNA,2.0mmol/L MgCl2,0.3mmol/L dNTPs,0.5μmol/L引物,0.5U Taq DNA聚合酶;退火温度为52℃-55℃;扩增反应程序为：94℃预变性5min;94℃变性30s,52℃退火1min,72℃延伸2min,35个循环;72℃延伸7min;4℃保存。结论：建立了栝楼的最佳ISSR反应体系,为栝楼种质鉴定提供了更客观可靠     

塔里木盆地荒漠区柽柳属植物总DNA提取及RAPD体系优化

本研究以干旱荒漠盐生植物柽柳的幼嫩叶片为实验材料,探究摸索其总DNA的提取方法与RAPD-PCR的反应体系及扩增条件。结果表明,改良CTAB-高盐沉淀法较好地提取出了柽柳植物的总DNA,其产量、质量均有明显提高,比较适合于多数柽柳属植物的DNA提取;同时,通过单因素试验比较优化筛选出了适合于柽柳植物RAPD分析的最佳的PCR反应体系与扩增条件,其25μL的反应体系中包含有Mg2+=2.5 mmol/L、d NTPs=0.25 mmol/L、引物=0.30μmol/L、Taq DNA聚合酶=1.5 U、模板DNA=200 ng;其最适扩增条件为95℃预变性4 min,94℃变性30 s、36℃退火40 s、72℃延伸1 min、40个循环;最终在72℃下延伸10 min,4℃下保存;另外,通过6条多态性引物的扩增效果证实该优化体系比较稳定,扩增条件比较合适,能够满足多数柽柳植物分子多态性的检测要求。     

冬瓜和节瓜DNA提取及RAPD反应体系优化

以8份冬瓜和节瓜为材料,采用改良CTAB法提取基因组DNA,采用正交试验设计,对冬瓜和节瓜RAPD条件进行了优化,建立了最佳反应体系:25μL反应体系中含1×buffer,模板DNA、Mg2+、dNTPs、引物和Taq酶的浓度分别为20 ng、2.0mmol/L、0.24 mmol/L、0.3μmol/L和1.0 U。PCR扩增程序为:94℃预变性5 min;94℃变性45 s,36.9℃退火45 s,72℃延伸1.5min,共40个循环;72℃延伸10 min,12℃保存。     

正交试验优化八角ISSR-PCR反应体系

利用正交试验设计研究Taq DNA聚合酶、DNA模板、引物(UBC 886)、dNTP、Mg2+浓度5个因素对云南八角ISSR-PCR反应的影响,建立其最佳反应体系。结果表明:25μL的反应体系中5个因子的最佳水平为:Mg2+3 mmol/L、Taq DNA聚合酶0.5 U、DNA模板0.016 ng、引物0.8μmol/L、dNTPs 0.2 mmol/L。PCR最佳反应程序为:94℃预变性5 min;94℃变性30 s,46℃退火45 s,72℃延伸1 min,40次循环;72℃最后延伸7 min,4℃保存。     

葡萄ISSR-PCR反应体系的建立与优化

采用正交设计L9(34)对影响葡萄ISSR-PCR反应体系的4个因素(dNTP、TaqDNA聚合酶、引物、模板DNA)在3个浓度水平上进行试验,并通过直观分析初步确定其反应体系;在此基础上,通过单因素试验探讨了dNTP、TaqDNA聚合酶、引物、模板DNA、退火温度及循环次数等因素或条件对葡萄ISSR-PCR扩增结果的影响,确定最佳反应水平。最终建立了葡萄ISSR-PCR扩增的最佳反应体系:在25μL的反应体系中,dNTP浓度0.2 mmol/L,TaqDNA聚合酶的用量0.5 U,引物浓度0.4mmol/L,DNA模板用量40 ng。反应程序:94℃预变性5 min;94℃变性1 min,52℃退火1 min,72℃延伸1 min 30 s,40次循环;最后72℃延伸10 min,10℃保存。     

云生毛茛ISSR-PCR体系优化与引物筛选

旨在建立稳定可靠的云生毛茛ISSR-PCR反应体系。采用正交试验设计方法,对影响云生毛茛ISSR-PCR扩增结果的Mg2+、d NTP、Taq DNA聚合酶、引物、模板DNA五个因素进行优化筛选,对反应程序进行优化,建立适用于云生毛茛的最佳反应体系和扩增程序,并对反应体系和扩增程序进行验证;在此基础上筛选多态性好的ISSR引物,采用梯度法筛选各个引物的最适退火温度。结果表明,云生毛茛20μL ISSR-PCR的最佳反应体系为:模板DNA 30 ng,Mg2+1.95 mmol/L,Taq DNA聚合酶0.04U/μL,d NTP 0.150 mmol/L,引物0.5μmol/L;最佳反应程序为:94℃预变性5 min;94℃变性20 s,49.6-60.6℃复性1 min,72℃延伸100 s,38个循环;72℃下延伸6 min。在优化的反应体系和反应程序条件下,从100条ISSR引物中筛选获得16条ISSR扩增引物,并确定了引物各自的最适退火温度。经过不同居群云生毛茛的验证,证明优化后体系扩增条带清晰且重复性好,可用于后续云生毛茛遗传多样性的研究。     

广东野百合DNA提取和RAPD条件的优化

以野百合(Lilium brownii)新鲜叶片、硅胶干燥叶片及鳞片为材料,研究了DNA的提取方法,并对影响随机扩增多态DNA(RAPD)反应的各因素进行了优化。建立了野百合RAPD的优化反应体系及程序,即在20μl反应体系中,含20 ng模板DNA,2.0 mmol/L Mg2 、0.2 mmol/L dNTPs、1.5 U Taq DNA聚合酶、0.3μmol/L随机引物S1519;扩增程序为:94℃预变性5 min,然后94℃30 s,38℃50 s,72℃1 min,35个循环,最后72℃延伸10 min,4℃保存。     

优化蕺菜属ITS-PCR扩增条件的研究

目的:建立蕺菜rDNA ITS扩增反应的优化体系.方法:以蕺菜DNA为模板,采用单因素试验设计,对影响蕺菜rDNAITS区扩增的重要参数进行了优化试验.结果:最优蕺菜ITS-PCR的反应体系为25μl反应体系中含Tao酶0.75U、Mg2+2.5mmol/L、dNTP 0.15mmol/L、引物对0.6μmol/L、模板DNA 10ng.扩增程序为在94℃下预变性4min,然后进行36个循环(94℃变性45s,60℃退火50s,72℃延伸90s),最后在72℃延伸8min.结论:这一体系的建立为利用蕺菜rDNA ITS区研究蕺菜种质资源的系统进化提供了标准化程序.     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Determination of stoichiometry of radioiodination of proteins

A sensitive method for the detection of small quantities of hydrophobic antioxidant free radical scavengers such as butylatedhydroxytoluene (BHT) and butylatedhydroxyanisole (BHA) in aqueous samples is described. The procedure involves extraction of the hydrophobic free radical scavenger into an organic solvent phase, followed by the subsequent reaction of an aliquot of this extract with the stable cation radical tris(p-bromophenyl)amminium hexachloroantimonate (TBACA). In experiments with BHT and BHA, the loss of TBACA absorbance at 730 nm was found to be linearly proportional to the amount of antioxidant added, with quantities of BHT as small as 200 pmol being easily detectable. In aqueous suspensions of dimyristoylphosphatidylcholine vesicles, assays of the aqueous BHT concentration showed that BHT partitioned strongly into the membrane phase, achieving very high BHT/phospholipid ratios. For a given concentration of BHT, partitioning into the membrane phase was greater in large, multilamellar liposomes than in either small, single-walled vesicles or in purified rat brain synaptic vesicle membranes. Direct assay of BHT and BHA in phospholipid membranes, however, was complicated by a nonspecific interaction between TBACA and the phospholipid.