Biological effect of extreamely low frequency magnetic fields on microorganisms

极低频磁场（ELF）的生物学效应尚不清楚。流行病学研究表明，接触极低频辐射与几种癌症发病率之间存在微弱相关性，但也有负面研究报告。最近的研究表明，ELF可诱导人类黑色素瘤细胞发生突变。本文研究了60 hz和500 mT的极低频对出芽酵母酵母（S.cerevisiae）和纤毛虫草履虫（Paramecium multimicronuncleatum）生长和突变频率的影响。检测了几种酿酒酵母（野生型和辐射敏感突变体rad）和多微核酿酒酵母的生长速率，但未观察到显著差异。我们也试图分离出酿酒酵母的ELF敏感突变体。在筛选了1万个突变酵母细胞后，获得了两个对elf敏感的候选细胞，现在我们正在对它们进行检查。此外，还研究了p.m ulonuncleatum在极低频和静态磁场下的行为。当极低频磁场作用于多微核体时，多微核体向上移动到试管中，并停留在那里，当停止作用时，细胞又开始随机游动。现在我们来分析一下具体的机理。

The biological effects of extremely low frequency magnetic fields (ELF) are not clear. Epidemiological studies have shown weak correlations between exposure to ELF and the incidence of several cancers, but negative studies have also reported. Recent study showed human melanoma cells were induced mutations by ELF.In this work, We studied the effect of ELF of 60-Hz and 500 mT on the growth and the mutation frequency of the budding yeast S.cerevisiae and the ciliate Paramecium multimicronuncleatum. The growth rate of several strains of S.cerevisiae (wild type and radiation sensitive mutants, rad) and P.multimicronucleatum were examined but no significant differnce on growth were observed. We have also tried to isolate the ELF sensitive mutants of S.cerevisiae. Two ELF-sensitive candidates were obtained after screening ten thousand mutated yeast cells and now we have been examining them.Moreover, the behavior of P.multimicronuncleatum under the ELF or static magnetic fields were examined.When P.multimicronucleatum was exposed with ELF magnetic field, P.multimicronucleatum went up to cuvette, and remained there, and when exposure was stopped the cells swam randamly again. Now we are going to analyze the detail mechanism.