The Biogenesis and Survival of Vegetative, Quiescent Yeast Cells

静止是地球上一种鲜为人知但普遍存在的细胞状态。静止细胞，从无法培养的微生物到结核分枝杆菌和干细胞，在所有物种的生存中扮演着重要的角色。沃纳-沃什伯恩博士和他的同事最近发现，当酵母菌落耗尽葡萄糖时，培养物中的细胞会经历不对称的细胞分裂，从而产生静止的子细胞和非静止的母细胞。静止期细胞和非静止期细胞在生理和形态上的差异是显著的，这让人联想到其他静止期细胞的分化，如神经元和干细胞。这项研究项目将通过对mRNA转录丰度变化的时程分析和对这一过程所需基因的鉴定来检查葡萄糖耗竭后的细胞分裂。将使用基于寡核苷酸的微阵列来研究mRNA。形成和存活静止和非静止细胞所需的基因将使用由大约6000个酵母菌株组成的酵母缺失集进行鉴定，每个酵母菌株都带有一个特定基因的缺失。对mRNA水平和突变体的变化进行表征将有助于更好地理解营养、静止的酵母细胞的发育。这也将有助于更好地理解这种不对称细胞分裂的进化保守性，从而了解这种细胞分裂在所有生物体中产生静止细胞的作用。这项工作的更广泛影响来自沃纳-沃什伯恩实验室的跨学科互动，以及在计算机科学和数学方面的密切合作，以及对本科生、研究生和博士后水平上代表性不足群体的学生的培训。

Quiescence is a poorly understood but universal state of cells on earth. Quiescent cells, from unculturable microbes to M. tuberculosis and stem cells, play important roles in the survival of all species. Dr. Werner-Washburne and co-workers have recently discovered that when yeast colonies exhaust glucose, cells in the culture undergo an asymmetric cell division leading to the production of a quiescent daughter cell and non-quiescent mother cell. The physiological and morphological differences between the quiescent and non-quiescent cells are remarkable and are reminiscent of the differentiation seen in the production of other quiescent cells, such as neurons and stem cells. This research project will examine the cell division after glucose exhaustion through a time-course analysis of changes in mRNA transcript abundance and identification of genes required for this process. mRNA will be studied using oligonucleotide-based microarrays. Genes required for the formation and survival of quiescent and non-quiescent cells will be identified using a yeast deletion set composed of approximately 6000 yeast strains, each carrying a deletion in a specific gene. Characterization of the changes in mRNA levels and mutants will lead to a better understanding of the development of vegetative, quiescent yeast cells. It will also lead to a better understanding of the evolutionary conservation of this asymmetric cell division and, thus, the role of this cell division in the production of quiescent cells in all organisms. The broader impact of this work comes from the cross-disciplinary interactions in the Werner-Washburne laboratory, with close collaborations in computer sciences and math, and from training of students from under-represented groups at the undergraduate, graduate and post doctoral levels.