University College London, Research Department of Genetics, Evolution & Environment and Institute of Healthy Aging, Gower Street, Darwin Building, London WC1E 6BT, UK.
National Institute of Biological Sciences, Beijing 102206, China.
G3 (Bethesda). 2014 Dec 1;5(1):145-55. doi: 10.1534/g3.114.014415.
Genetic factors underlying aging are remarkably conserved from yeast to human. The fission yeast Schizosaccharomyces pombe is an emerging genetic model to analyze cellular aging. Chronological lifespan (CLS) has been studied in stationary-phase yeast cells depleted for glucose, which only survive for a few days. Here, we analyzed CLS in quiescent S. pombe cells deprived of nitrogen, which arrest in a differentiated, G0-like state and survive for more than 2 months. We applied parallel mutant phenotyping by barcode sequencing (Bar-seq) to assay pooled haploid deletion mutants as they aged together during long-term quiescence. As expected, mutants with defects in autophagy or quiescence were under-represented or not detected. Lifespan scores could be calculated for 1199 mutants. We focus the discussion on the 48 most long-lived mutants, including both known aging genes in other model systems and genes not previously implicated in aging. Genes encoding membrane proteins were particularly prominent as pro-aging factors. We independently verified the extended CLS in individual assays for 30 selected mutants, showing the efficacy of the screen. We also applied Bar-seq to profile all pooled deletion mutants for proliferation under a standard growth condition. Unlike for stationary-phase cells, no inverse correlation between growth and CLS of quiescent cells was evident. These screens provide a rich resource for further studies, and they suggest that the quiescence model can provide unique, complementary insights into cellular aging.
衰老相关的遗传因素在从酵母到人类的过程中惊人地保守。裂殖酵母 Schizosaccharomyces pombe 是一种新兴的遗传模型,可用于分析细胞衰老。已在耗尽葡萄糖的静止期酵母细胞中研究了时序寿命(CLS),这些细胞仅能存活几天。在这里,我们分析了在缺乏氮源的静止期 S. pombe 细胞中的 CLS,这些细胞会在分化的 G0 样状态下停止生长并存活超过 2 个月。我们应用条形码测序(Bar-seq)的平行突变表型分析,同时检测在长期静止期内一起衰老的pooled haploid deletion 突变体。正如预期的那样,自噬或静止缺陷的突变体代表性不足或未被检测到。可以为 1199 个突变体计算寿命分数。我们将重点讨论 48 个最长寿的突变体,其中包括其他模型系统中已知的衰老基因和以前未涉及衰老的基因。编码膜蛋白的基因特别突出,是促进衰老的因素。我们独立地在 30 个选定突变体的单个实验中验证了延长的 CLS,表明了该筛选的有效性。我们还应用 Bar-seq 对所有pooled deletion 突变体在标准生长条件下的增殖进行了分析。与静止期细胞不同,在静止期细胞中,生长与 CLS 之间没有明显的反比关系。这些筛选为进一步研究提供了丰富的资源,并且表明静止模型可以为细胞衰老提供独特的、互补的见解。