Characterization of differentiated quiescent and nonquiescent cells in yeast stationary-phase cultures
Characterization of differentiated quiescent and nonquiescent cells in yeast stationary-phase cultures
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DOI：
10.1091/mbc.e07-07-0666
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发表时间：
2008-03-01
影响因子：
3.3
通讯作者：
Werner-Washburne, Margaret
中科院分区：
文献类型：
--
作者：
Aragon, Anthony D.;Rodriguez, Angelina L.;Werner-Washburne, Margaret
葡萄糖限制的酿酒酵母培养物中的细胞在进入稳定期之前分化为静止 (Q) 和非静止 (NQ) 部分。为了了解这种分化，对来自 101 个缺失突变株的 Q 和 NQ 细胞进行了活力和繁殖能力测试。鉴定了影响 Q 或 NQ 部分中的一种或两种表型的 11 个突变体。 NQ 级分表现出高水平的小菌落，并鉴定出影响该表型的九个突变体。微阵列分析显示超过 1300 个 mRNA 可以区分 Q 和 NQ 组分。 Q 细胞特异性 mRNA 编码参与膜维护、氧化应激反应和信号转导的蛋白质。 NQ 细胞 mRNA 编码参与 Ty 元件转座和 DNA 重组的蛋白质，与这些细胞的凋亡一致。仅在 Q 细胞中鉴定出超过 2000 个蛋白酶释放的 mRNA，这与这些细胞在生理上准备对环境变化做出反应一致。我们的结果表明，Q 和 NQ 细胞显着分化，Q 细胞提供基因组稳定性，NQ 细胞为 Q 细胞提供营养，并通过突变和转座提供遗传多样性的常规来源。这些研究与时间老化、细胞周期和基因组进化相关，它们提供了对即使是简单生物体也会对饥饿做出的复杂反应的深入了解。
Cells in glucose-limited Saccharomyces cerevisiae cultures differentiate into quiescent ( Q) and nonquiescent ( NQ) fractions before entering stationary phase. To understand this differentiation, Q and NQ cells from 101 deletion-mutant strains were tested for viability and reproductive capacity. Eleven mutants that affected one or both phenotypes in Q or NQ fractions were identified. NQ fractions exhibit a high level of petite colonies, and nine mutants affecting this phenotype were identified. Microarray analysis revealed >1300 mRNAs distinguished Q from NQ fractions. Q cell-specific mRNAs encode proteins involved in membrane maintenance, oxidative stress response, and signal transduction. NQ-cell mRNAs, consistent with apoptosis in these cells, encode proteins involved in Ty-element transposition and DNA recombination. More than 2000 protease-released mRNAs were identified only in Q cells, consistent with these cells being physiologically poised to respond to environmental changes. Our results indicate that Q and NQ cells differentiate significantly, with Q cells providing genomic stability and NQ cells providing nutrients to Q cells and a regular source of genetic diversity through mutation and transposition. These studies are relevant to chronological aging, cell cycle, and genome evolution, and they provide insight into complex responses that even simple organisms have to starvation.