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。     

杨梅RAPD-PCR体系的正交优化研究

以杨梅DNA为模板,对影响杨梅RAPD-PCR扩增的重要参数进行了优化试验,以期建立杨梅RAPD反应的最佳体系。通过采用正交试验设计的方法,对杨梅RAPD-PCR条件进行了优化,结果表明最佳的杨梅RAPD-PCR的反应体系(20μl)中含有1×buffer,1.0U TaqDNA聚合酶,3.0mmol/L MgCl2,0.30mmol/L dNTPs,1.5μmol/L引物和模板DNA 30-40ng。适宜的扩增条件为94℃预变性3min,再进入38个PCR循环(94℃变性30s,38℃退火30s,72℃延伸90s),72℃延伸7min,4℃保存。     

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。     

南药益智ITS-PCR体系的建立与优化

为了建立适合南药益智的ITS-PCR体系来研究不同地理居群益智遗传多样性,本研究利用植物基因组试剂盒法提取益智基因组DNA为模板,采用单因素和正交试验对ITS-PCR过程中的关键影响因素进行优化,并对ITS-PCR产物进行测序鉴定。实验结果表明最佳ITS-PCR反应体系(25μL)为:Taq酶1.0 U,d NTPs 4 mmol/L,Mg2+0.5 mmol/L,引物2.0μmol/L,模板20 ng,10×PCR Buffer(不含Mg2+)2.5μL;最佳扩增程序为:94℃预变性2 min;94℃变性30 s,55℃退火30 s,72℃延伸1 min,共32个循环;最后72℃延伸5 min。采用该最佳体系对益智基因组DNA进行PCR扩增,获得扩增产物经单向测序获得了益智ITS部分序列。建立了稳定的ITS-PCR体系,为研究益智遗传多样性分析奠定了基础。     

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     

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。     

黑籽南瓜ISSR-PCR反应体系的正交设计优化

以云南个旧黑籽南瓜叶片基因组DNA为模板,固定反应程序,采用L_(16)(4~5)正交试验设计的方法,对影响ISSR-PCR反应的五因素(dNTPs,Mg~(2+),引物,Taq DNA聚合酶,模板DNA)在四个水平上进行优化试验。研究建立起了适于云南黑籽南瓜ISSR-PCR的最佳反应体系:25μl反应体系中含10×buffer 2.5μl、0.15mmol/L dNTPs、2.5mmol/L Mg2+、0.40μmol/L引物、1.5U Taq DNA聚合酶、DNA模板15ng。扩增程序为:95℃预变性5min,94℃变性45s,52℃退火45s,72℃延伸90s,进行35个循环,最后72℃延伸7min。该优化体系的建立为今后用ISSR标记技术进行黑籽南瓜种质资源的分类鉴定和遗传多样性研究奠定了基础。     

正交设计优化玉米SSR-PCR反应体系的研究

为建立适宜玉米SSR-PCR的反应体系和扩增程序,利用正交设计L16(45)表,对反应体系的模板DNA、dNTPs、Primers、Taq DNA聚合酶的浓度进行4因素4水平优化筛选和扩增程序的优化,确立了最优反应体系和扩增程序.即在10 μL体系中,模板DNA 20 ng,1×PCR buffer,dNTPs 62.5 pmol/μL,Primers0.25 pmol/μL,Taq DNA polymerase 0.5 U.反应程序为:94℃预变性5 min:94℃变性45 s,60℃退火45 s,72℃延伸1 min,32个循环;72℃延伸5 min,4℃保存.使用300对SSR引物对重组近交系的两亲本扩增,筛选出条带清晰,有差异的引物94对,用于基因连锁图谱构建和QTL定位.     

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。     

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。     

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.