【作者】 宋智青； 白爱枝；

【Author】 SONG Zhiqing;BAI Aizhi;Key Laboratory of Ion Beam Bioengineering of Inner Mongolia Autonomous Region,School of Physical Science and Technology, Inner Mongolia University;

【机构】 内蒙古大学物理科学与技术学院离子束生物工程自治区重点实验室；

【摘要】 研究几种不同高压电场诱变效应,探讨高压芒刺电场诱变效应的可能分子机制。将大肠杆菌K12 W3110野生型菌株干燥菌膜用极距为5cm,电极为平行铝板的高压直流、交流、半波整流电场,以及极距为6cm,电极为针板的高压交流电场(高压芒刺电场)处理10min,后分别涂布P-gal和LB平皿,考察不同电场的存活率以及诱变率,后筛选高压芒刺电场诱变的大肠杆菌突变株,提取总DNA,经PCR扩增突变的lac I基因,绘制突变谱,给出高压芒刺电场诱变的可能机制。高压直流、交流、半波整流平板电场处理大肠杆菌K12,3种电场在低剂量处理时(1.5k V/cm时)都表现为对大肠杆菌K12的刺激效应,随着电场剂量增大,3种电场对大肠杆菌K12逐步变为抑制效应。其中直流平板电场的效应最为明显。交流和半波整流平板电场对大肠杆菌K12诱变率变化不大,均未达到对照组的2倍。直流平板电场在4.5 k V/cm时,突变率达到极大值5.8×10-6,是对照组的2.32倍。用高压芒刺电场处理大肠杆菌,在场强为1k V/cm时,突变率为31.2×10-6,分别是自发突变(1.2×10-6)和对照(2.5×10-6)的26倍和12倍。从突变谱看,高压芒刺电场组还发现了自发突变组中没有发现的A:T→T:A的颠换和280bp的大片段缺失,同时还有G:C→A:T的增加。高压直流、交流、半波整流平板电场对大肠杆菌具有一定的诱变效应,但是其诱变效应不明显。高压芒刺电场是一种损伤低、突变率高,突变谱广的很好的诱变剂。高压芒刺静电场对大肠杆菌的诱变效应是可能是由于电场作用引起大肠杆菌SOS反应而导致的。更多还原

【Abstract】 Studies of mutatgenic effects of several electric fields, studies of possible mechanisms of high voltage prickle electric field(HVPEF).Escherichia coli K12 W3110 was treated 10 min by high voltage DC, AC, half-wave rectification electric fields, The distance between the electrodes is 5cm, and HVPEF, The distance between the electrodes is 6cm. The survival rates and mutation rates was studied. Then, mutant strains of HVPEF treated was selected, after PCR amplification of lac I, mutational spectrum was completed, and we proposed possible mechanisms of HVPEF. both the high voltage DC, AC, and half-wave rectification electric fields all induced stimulative effects at low dosage, and with the dosage increasing these three plate electric fields induced inhibitory effects. Among three electric fields, the most evident effects were induced by DC plate electric field. At the field intensity of 4.5 k V/cm, the mutation rate reaches maximum, 5.8×10-6,which is 2.32 times more than the controls. Escherichia coli K12 W3110 was treated by high voltage prickle electrostatic field, The mutant frequency reached 31.2×10-6 at field intensity of 1k V/cm, which was about 26-fold over the background(1.2×10-6) and 12-fold over the controls(2.5×10-6). The spectra of our HVPEF exposure group with increasing G:C to A:T transitions and A:T to T:A transversions and large deletion fragment of 280 bp.Although these three plate electric field have mutagenic effects on E.coli, but the mutagenic effects seem not obvious. HVPEF could act as an effective mutagen caused high mutation rate and wide mutational spectrum with low damage. The HVPEF exposure may induce SOS response.更多还原