Using Model Organism Saccharomyces Cerevisiae to Evaluate the Differential Effects of ELF-MF and RF-EMF exposure on Global Gene Expression

The potential health hazard of exposures to electromagnetic fields (EMF) continues to cause much public concern. However, the biological and health effects of exposures to EMF remain controversial and their biophysical mechanisms are unclear. In the present study, we used Saccharomyces cerevisiae to identify genes responding to extremely low frequency magnetic fields (ELF-MF) and to radiofrequency (RF) EMF exposures. The expression of genes was analyzed by microarray screening and confirmed by real-time reverse transcription -polymerase chain reaction. In confirmation experiments, we found that there was no statistically significant change in three of the ELF-MF responsive candidate genes (P>0.05). On the other hand, out of the forty genes that responded to RF-EMF, the confirmation experiments found that only five were affected: structural maintenance of chromosomes 3-gene (SMC3), aquaporin 2 –gene (AQY2), halotolerance protein 9 –gene (HAL9), yet another kinase 1 -gene (YAK1) and one of unknown function gene (open reading frame: YJL171C) (P<0.05). Overall, this study has demonstrated that the yeast cells did not respond to 50 Hz ELF-MF and that the response to RF-EMF is limited to only five genes. The biological consequences of the observed gene expression changes induced by RF-EMF await further investigation. The yeast cells were exposed to 0.4 mT 50 Hz ELF-MF or 1800 MHz RF-EMF at a specific absorption rate of 3.5 W/kg for 6 hours.

电磁场（electromagnetic fields, EMF）暴露所潜在的健康危害，始终引发公众的广泛关注。然而，电磁场暴露产生的生物学与健康效应仍存在争议，其生物物理机制尚未明确。本研究以酿酒酵母（Saccharomyces cerevisiae）为模型，筛选响应极低频磁场（extremely low frequency magnetic fields, ELF-MF）与射频电磁场（radiofrequency, RF EMF）暴露的基因。通过基因芯片（microarray）筛选分析基因表达水平，并以实时反转录聚合酶链反应（real-time reverse transcription-polymerase chain reaction）完成验证。验证实验结果显示，3个极低频磁场响应候选基因的表达量无统计学意义上的显著变化（P>0.05）。另一方面，在40个响应射频电磁场的候选基因中，验证实验仅发现5个基因的表达受到显著影响：染色体结构维持蛋白3基因（structural maintenance of chromosomes 3, SMC3）、水通道蛋白2基因（aquaporin 2, AQY2）、耐盐蛋白9基因（halotolerance protein 9, HAL9）、另一种激酶1基因（yet another kinase 1, YAK1）以及1个功能未知的开放阅读框基因（开放阅读框：YJL171C）（P<0.05）。综上，本研究证实酿酒酵母细胞对50Hz极低频磁场无响应，且其对射频电磁场的响应仅局限于上述5个基因。射频电磁场诱导的基因表达变化所带来的生物学效应，仍有待进一步研究阐明。实验中，酿酒酵母细胞分别接受两种暴露处理：0.4mT、50Hz的极低频磁场，或比吸收率（specific absorption rate, SAR）为3.5W/kg的1800MHz射频电磁场，暴露时长均为6小时。