Lee Yae-Lim, Lee Cheol-Koo
College of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea.
Mol Cells. 2008 Sep 30;26(3):299-307. Epub 2008 Aug 5.
To characterize gene expression that is dependent on the strength of calorie restriction (CR), we obtained transcriptome at different levels of glucose, which is a major energy and carbon source for budding yeast. To faithfully mimic mammalian CR in yeast culture, we reconstituted and grew seeding yeast cells in fresh 2% YPD media before inoculating into 2%, 1%, 0.5% and 0.25% YPD media to reflect different CR strengths. We collected and characterized 160 genes that responded to CR strength based on the rigorous statistical analyses of multiple test corrected ANOVA (adjusted p<value 0.1 or raw p value<0.0031) and Pearson correlation (|r|>0.7). Based on the individual gene studies and the GO Term Finder analysis of 160 genes, we found that CR dose-dependently and gradually increased mitochondrial function at the transcriptional level. Therefore, we suggest these 160 genes are markers that respond to CR strength and that might be useful in elucidating CR mechanisms, especially how stronger CR extends life span more.
为了表征依赖于卡路里限制（CR）强度的基因表达，我们获取了处于不同葡萄糖水平下的转录组，葡萄糖是芽殖酵母的主要能量和碳源。为了在酵母培养中忠实地模拟哺乳动物的CR，我们在接种到2%、1%、0.5%和0.25%的YPD培养基以反映不同的CR强度之前，在新鲜的2% YPD培养基中重悬并培养种子酵母细胞。基于多重检验校正方差分析（调整后的p值<0.1或原始p值<0.0031）和Pearson相关性（|r|>0.7）的严格统计分析，我们收集并鉴定了160个对CR强度有反应的基因。基于对单个基因的研究以及对这160个基因的GO术语查找分析，我们发现在转录水平上，CR呈剂量依赖性并逐渐增强线粒体功能。因此，我们认为这160个基因是对CR强度有反应的标记，可能有助于阐明CR机制，特别是更强的CR如何更有效地延长寿命。
