不同代龄南方鲶SME—1细胞ENA指纹图的分析

利用荧光素标记ＬＺＦ－ＩＤＮＡ探针对不同培养代龄南方鲶ＳＭＥ－１细胞简单重复ＤＮＡ进行了检测,获得了清晰的ＤＮＡ指纹图谱,发现：随着细胞代龄的增加,同一代龄细胞群体内和不同代龄细胞群体间共有谱带概率,相似系数,最大等位基因频率均明显下降,而突变率则随着代龄增加而增加,利用ＤＮＡ指纹图技术分析ＳＥＭ－１细胞遗传物质的变化是可行的,为ＳＭＥ－１细胞进一步的培养,并为ＳＭＥ－１细胞的研究利用提供了分子遣     

不同代龄及生长状态下2BS细胞的酸性磷酸酶活性及氯酯醒对此的影响

实验以人胚肺二倍体成纤维细胞(2BS)为材料,分别测定了处于不同代龄及不同生长时期的2BS细胞酸性磷酸酶(ACPase)活性。结果发现随着代龄增高,细胞ACPase活性上升。处于同一代龄的细胞,则接触抑制期细胞的ACPase活性显著高于生长期细胞。接触抑制引起的酶活性增高甚至超过代龄增加而引起的ACPase活性上升。30μg/ml的氯酯醒有抑制细胞ACPase活性的作用。     

不同代龄SME-1细胞和南方鲶上皮组织同工酶的初步分析

以不同代龄的ＳＭＥ－１细胞和南方鲶为材料,用聚丙烯酰胺圆盘电泳对ＬＤＨ、ＭＤＨ、α－ＥＳＴ、β－ＥＳＴ和ＳＯＤ同工酶进行了分析。２月龄和１２月龄个体上皮组织中仅α－ＥＳＴ和ＭＤＨ有明显差异,后者酶活力较高。个体和ＳＭＥ－１细胞仅少数谱带一致,多数酶谱明显不同,ＳＭＥ－１细胞中酶谱较少。不同代龄ＳＭＥ－１细胞酶谱有差异,酶活力随着细胞代龄的增加而升高。本文为ＳＭＥ－１细胞的研究及其在细胞生物学、生物工程等方面的应用提供了生化资料。     

人胚肺二倍体成纤维细胞端区长度的代龄变化

以体外培养的不同代龄的人胚肺二倍体成纤维细胞（2BS）为实验对象,HeLa细胞为对照,分别观察其端区长度随代龄的变化．结果显示年轻2BS细胞（24代）端区长度约9．13kb;衰老2BS细胞（64代）端区长度约7kb,丢失约2kb．2BS细胞端区长度随代龄的增长而缩短．密度扫描结果显示细胞每复制一代,端区平均丢失50bp,而HeLa细胞的端区长度未因代龄而变化．     

人胚肺二倍体成纤维细胞端区长度的代龄变化

以体外培养的不同代龄的人胚肺二倍体成纤维细胞为实验对象,ＨｅＬａ细胞为对照,分别观察其端区长度随代龄的变化。结果显示年轻２ＢＳ细胞端区长度约９．１３ｋｂ;衰老２ＢＳ细胞端区长度约７ｋｂ,丢失约２ｋｂ。２ＢＳ细胞端区长度随代的增长而缩短。     

DH10B菌株高效电转化条件探究

以pUC19、pECBAC1、pCLD04541DNA以及3个不同大小的BACDNA为材料,研究了E.coli DH10B菌株在5个不同脉冲电场下的转化效率。研究发现,随着DNA片段大小的增加,最高转化效率和最适场强迅速减小。利用DH10B细胞转化pUC19 DNA的最适场强是21kV/cm,而190kb BAC DNA仅为13kV/cm;在最适场强下,40kb BAC DNA的转化效率约是190kb BAC DNA的50倍。通过大量数据绘制了不同因素影响下转化效率的变化曲线,优化了E.coli DH10B菌株电转化条件,为质粒的重组转化以及大片段基因组文库的构建奠定了基础。     

不同LET的重离子辐射对DSB诱导的影响

利用γ射线和不同LET的碳离子辐照小鼠B16黑色素瘤细胞的脱蛋白DNA,采用脉冲场凝胶电泳结合荧光扫描技术研究了DNA双链断裂（DSB）与LET之间的关系。结果表明：不同LET重离子诱导的PR都随剂量的增加而增加,并在超过一定的剂量之后逐渐趋于一个准阈值;而不同LET的重离子诱导的L值都与剂量呈线性关系;对于诱导DSB的RBE值则随着LET的增加先呈上升趋势,在LET超过100ke/μm后下降。     

人衰老成纤维细胞经紫外线损伤后的DNA修复和细胞周期调控

 以体外培养的不同代龄的人胚肺二倍体成纤维细胞（２ Ｂ Ｓ）为对象,紫外线诱导 Ｄ Ｎ Ａ 损伤后,观察细胞形态、增殖特性、细胞周期、 Ｄ Ｎ Ａ 修复变化等细胞应答以及 ｇａｄｄ１５３、ｐ２１ Ｗ Ａ Ｆ１／ Ｃ Ｉ Ｐ１／ Ｓ Ｄ Ｉ１、ｐ５３ 等基因的转录水平的表达变化．结果显示：紫外线诱导 Ｄ Ｎ Ａ 损伤后,衰老（＞ ５５ 代）２ Ｂ Ｓ细胞形态及增殖能力的改变不如年轻细胞（＜ ３０ 代）显著;不同代龄的细胞损伤后均出现 Ｇ１ 期阻滞现象,年轻细胞 Ｇ１ 期阻滞率明显高于衰老细胞（ Ｐ＜ ００５）;衰老细胞总的修复能力较年轻细胞明显下降（ Ｐ＜ ００１）;同时,ｇａｄｄ１５３、ｐ２１、ｐ５３ 等的可诱导性均低于年轻 ２ Ｂ Ｓ细胞．由此,分别在细胞水平与基因水平反映了衰老细胞经紫外线照射损伤后的细胞应答变化与修复机能减退的关系．     

枸杞雌、雄配子DNA含量与细胞周期变化的初步研究

枸杞是二胞花粉植物。花粉在柱头上萌发后生殖细胞在花粉管中分裂形成精细胞。在花粉管中,精细胞开始合成DNA,随着花粉管生长,精细胞DNA含量持续增加。当花粉管在退化助细胞中破裂,释放出的2个精细胞DNA含量达到1．92倍（1．92C）。在开花当天,卵细胞已合成了约1／3DNA,并持续增加。开花后30h,卵细胞中的DNA含量达到1．63C。在受精前,卵细胞中的DNA含量达到1．83C。精、卵细胞融合后,合子DNA含量为3．53C。去雄排除花粉管影响后,己合成1／5DNA的过熟卵细胞停止合成,表明卵细胞持续合成DNA需要花粉管的刺激。枸杞雌、雄配子在融合前合成DNA,在细胞周期的G,期发生融合,属于G2类型。     

紫外辐射诱发NIH3T3细胞凋亡时DNA断裂的特性

用常规琼脂糖凝胶电泳UVB照射后培养不同时间的NIH3T3细胞DNA,两个样本均未出现凋亡梯形带,而用相同条件处理的昆明小鼠胸腺细胞DNA出现了典型的梯形带.再用反转电场琼脂糖凝胶电泳(FIGE)UVB照射后培养不同时间的NIH3T3细胞DNA,发现DNA先断裂成低于23 kb的大分子片段,然后进一步断裂成小分子片段,但始终未出现梯形带,说明DNA并不总是从核小体之间断裂的.     

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