改良异硫氰酸胍法提取玛咖(Maca)叶片中总RNA研究

为了获得质量较高的玛咖总RNA,对其总RNA的提取进行了研究。以玛咖无菌苗叶片为材料,通过改良的异硫氰酸胍法提取其总RNA。结果:所提取的总RNA纯度高、完整性好,电泳条带清晰,OD260/OD280值达到1.90±0.03,总RNA的得率达到252.57±1.12μg/g。表明改良的异硫氰酸胍法适合于玛咖叶片中RNA的提取,所提取的总RNA纯度高、完整性好,为进一步的玛咖分子生物学研究打下良好基础。     

新生隐球菌总RNA抽提方法的实验研究

目的探讨快速获取高质量的新生隐球菌总RNA的实验方法。方法选取新生隐球菌的荚膜株、荚膜缺陷株,分别设计采用4种方法提取总RNA:酸洗玻璃珠法、液氮研磨法、异硫氰酸胍一步法、冷酸洗玻璃珠联合Yeast RNA kit法。用紫外线分光光度计测量其OD260、OD280的值,并且进行琼脂糖凝胶电泳,同时应用定量PCR法鉴定RNA质量。结果酸洗玻璃珠法、液氮研磨法、异硫氰酸胍一步法、冷酸洗玻璃珠联合Yeast RNA kit法的RNA产量分别为0.2μg/105细胞、0.4μg/105细胞、0.1μg/105细胞、0.6μg/105细胞。结论冷酸洗玻璃珠联合Yeast RNA kit法提取的RNA均一性和完整性最好,是简便、快捷地提取具有荚膜和细胞壁双重屏障的新生隐球菌RNA的理想方法。     

檀香心材总RNA提取方法的比较研究

为筛选檀香心材总RNA提取方法,对5种提取方法进行比较研究,包括Trizol法、改良CTAB法、SDS酸酚法、异硫氰酸胍-CTAB法、异硫氰酸胍-SDS法。结果表明,Trizol法和异硫氰酸胍-CTAB法不能提取出檀香心材总RNA,而SDS酸酚法、改良CTAB法和异硫氰酸胍-SDS法均能提取檀香心材总RNA。SDS酸酚法的A260 nm/A230 nm小于2.0,且RNA产率低,仅为(27.94±1.06)μg g–1,不能满足后续实验要求。而改良CTAB法和异硫氰酸胍-SDS法提取的总RNA带型清晰,完整性好,A260 nm/A280 nm为1.8~2.0,A260 nm/A230 nm大于2.0,RNA产率分别为(79.06±4.22)和(107.00±1.36)μg g–1。分别以改良CTAB法和异硫氰酸胍-SDS法提取的总RNA为模板,通过RT-PCR反应,扩增檀香Actin基因片段,结果二者扩增产物大小相同且条带单一,说明改良CTAB法与异硫氰酸胍-SDS法为檀香心材总RNA提取的较好方法。     

三七总RNA提取方法的对比研究

比较利用改进的异硫氰酸胍一步法、异硫氰酸胍高盐法、CTAB法和Thomas’RNA提取法等4种方法提取三七根茎2个部位总RNA的可行性。结果表明,改进的异硫氰酸胍一步法和异硫氰酸胍高盐法能有效地抑制酚类物质、多糖及皂苷等次级代谢产物对总RNA的影响,可从三七根茎中获得质量高、完整性好的总RNA。RT—PCR分析显示提取的总RNA具有反转录活性。这2种方法具有快速、简单、有效的特点。     

一种适用于RT-PCR的石榴籽粒总RNA提取方法

为从石榴籽粒中提取高质量的RNA,以便进行后续分子生物学研究,针对石榴籽粒富含次生代谢物的特点,采用CTAB法并进行了改良,利用氯仿/异戊醇替代其他方法中的"异硫氰酸胍"和"Trizol试剂"进行反复抽提去除蛋白,无水乙醇去除多糖,LiCl消化DNA。结果显示:改良CTAB法提取的石榴籽粒总RNA的28S rRNA、18SrRNA条带清晰,完整性较好;OD260 nm/OD280 nm比值为1.9960,纯度较高。在此基础上通过反转录、PCR扩增出符合预期大小的Actin基因片段,表明该方法提取的RNA可满足后续RT-PCR等分子生物学试验研究。     

野生稻颖果总RNA提取方法研究

目的:比较以确定适用于野生稻总 RNA 提取的方法.方法:用改良的异硫氰酸胍法、TRIZOL 法、SDS 法和 CrAB 法分别提取云南 3 种野生稻和栽培稻滇超 6 号在灌浆期颖果的总 RNA.结果:SDS法能够提取的普通野生稻和疣粒野生稻的总 RNA 的纯度高,其A260/A260 介于1.9938～1.9267;而 TRIZOL 法只适用于栽培稻滇超 6 号,CTAB 法对于疣粒野生稻和药用野生稻提取效果一般,电泳条带不很清晰,其A260/A280 介于1.8243～1.6928;而新建立的改良的异硫氰酸胍法都能提取完整性好、高得率(浓度介于0.9358～1.2008μg/μl)和高纯度的 RNA(A260/A280 大于1.8),电泳 28S rRNA 和 18S rRNA 条带清晰,且该方法操作简单、耗时少、效率高.结论:改良的异硫氰酸胍法适合于野生稻颖果总 RNA 的提取,提取的总 RNA 完整性好、得率高.     

山药组织总RNA提取方法的比较与分析

采用异硫氰酸胍-巯基乙醇联合变性法、Trizol法和CTAB-LiCl法等3种方法,分别对山药叶片和块茎进行总RNA提取效果进行了比较.结果表明,Trizoi法难以提取RNA,异硫氰酸胍-巯基乙醇联合变性法提取RNA效果不理想,存在DNA污染,这2种方法不适合于富含多糖类物质的山药组织总RNA的提取;CTAB-LiCl法提取叶片和块茎组织总RNA质量高、完整性好、成功率高,可作为山药类植物总RNA提取的首选方法.     

一种新型的油樟叶片总RNA提取方法

以油樟叶为试材,比较Trizol法、皂土法、CTAB法、Tris-SDS-异硫氰酸胍法等传统方案提取总RNA,发现效果都不理想.本文针对油樟叶片富含油脂、多酚、多糖的特点,开创性地使用了一种改良的总RNA提取流程:首次增加预处理液、乙酸乙酯抽提来减少油脂、多酚和多糖对裂解液粘稠度的影响,提取过程中使用二氯甲烷代替三氯甲烷增加对疏水性杂质的清除效果,使用混合型高盐溶液多次脱糖,结果表明使用改良的新型方法获得的油樟叶片总RNA条带清晰无明显降解,测得的A260/A280和OD260/OD230均在2.0左右,产物得率约580 μg/g,通过RT-PCR扩增出了油樟18S rRNA基因序长为113bp的特异条带,说明这种改良的新型方法获得的RNA完整性、纯度和产率都远高于常规RNA提取方法,研究探索出一种新型油樟叶片总RNA的提取方法.     

几种提取白木香茎干总RNA方法的比较

目的:通过比较多种RNA提取方法,确定白木香茎干RNA提取的有效手段,为白木香伤害形成沉香药材的分子研究奠定基础。方法:取2年生白木香茎,分别用CTAB法、TRIzol法、异硫氰酸胍-SDS法、Qiagen试剂盒和Nor gen试剂盒法提取总RNA,通过琼脂糖凝胶电泳和紫外分光光度法测定其产量与质量,并通过cDNA合成及小样本克隆测序检查RNA的可用性。结果:异硫氰酸胍-SDS法及Norgen试剂盒法提出的RNA条带清晰,完整性好;D260nm/D280nm值可达2.0左右,纯度较高,其产量足够应用于cDNA合成;其他方法不能提出RNA。结论:异硫氰酸胍-SDS法及Norgen试剂盒法可用于白木香茎干RNA提取。     

富含多糖和次生代谢产物的白桦成熟叶中总RNA的提取

分别采用CTAB法、SDS法、异硫氰酸胍法和缓冲液冰浴-CTAB法从转基因白桦成熟叶中提取总RNA,并对琼脂糖凝胶电泳和紫外光谱分析进行比较。结果表明,缓冲液冰浴-CTAB法提取的总RNA纯度高、完整性好且得率高.应用此法提取的总RNA能够满足RT-PCR和Northern杂交分析要求。     

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.     

Principles of organization and evolution of systems of regulation of functions

Evolution of living organisms is closely connected with evolution of structure of the system of regulations and its mechanisms. The functional ground of regulations is chemical signalization. As early as in unicellular organisms there is a set of signal mechanisms providing their life activity and orientation in space and time. Subsequent evolution of ways of chemical signalization followed the way of development of delivery pathways of chemical signal and development of mechanisms of its regulation. The mechanism of chemical regulation of the signal interaction is discussed by the example of the specialized system of transduction of signal from neuron to neuron, of effect of hormone on the epithelial cell and modulation of this effect. These mechanisms are considered as the most important ways of the fine and precise adaptation of chemical signalization underlying functioning of physiological systems and organs of the living organism