Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA.
Proc Natl Acad Sci U S A. 2010 Apr 13;107(15):6946-51. doi: 10.1073/pnas.1002422107. Epub 2010 Mar 24.
Oscillations in patterns of expression of a large fraction of yeast genes are associated with the "metabolic cycle," usually seen only in prestarved, continuous cultures of yeast. We used FISH of mRNA in individual cells to test the hypothesis that these oscillations happen in single cells drawn from unsynchronized cultures growing exponentially in chemostats. Gene-expression data from synchronized cultures were used to predict coincident appearance of mRNAs from pairs of genes in the unsynchronized cells. Quantitative analysis of the FISH results shows that individual unsynchronized cells growing slowly because of glucose limitation or phosphate limitation show the predicted oscillations. We conclude that the yeast metabolic cycle is an intrinsic property of yeast metabolism and does not depend on either synchronization or external limitation of growth by the carbon source.
酵母基因中很大一部分表达模式的波动与“代谢循环”有关，这种循环通常只出现在酵母的饥饿、连续培养中。我们使用单细胞 mRNA 的 FISH 来验证这样一个假设，即在恒化器中指数生长的非同步培养的单细胞中，这些波动确实存在。我们从同步培养的基因表达数据中预测，非同步细胞中来自一对基因的 mRNA 同时出现。对 FISH 结果的定量分析表明，由于葡萄糖限制或磷酸盐限制而生长缓慢的单个非同步细胞显示出了预测的波动。我们的结论是，酵母的代谢循环是酵母代谢的固有特性，它不依赖于同步或碳源对生长的外部限制。
