Long-Living Budding Yeast Cell Subpopulation Induced by Ethanol/Acetate and Respiration.

Budding yeast generate heterogeneous cells that can be separated into two distinctive cell types: short-living low-density and long-living high-density (HD) cells by density gradient centrifugation. We found that ethanol and acetate induce formation of HD cells, and mitochondrial respiration is required. From their transcriptomes and metabolomes, we found upregulated differentially expressed genes in HD cells involved in the RGT2/RGT1 glucose sensing pathway and its downstream genes encoding hexose transporters. For HD cells, we determined an abundance of various carbon sources including glucose, lactate, pyruvate, trehalose, mannitol, mannose, and galactose. Other upregulated differentially expressed genes in HD cells were involved in the TORC1-SCH9 signaling pathway and its downstream genes involved in cytoplasmic translation. We also measured an abundance of free amino acids in HD cells including valine, proline, isoleucine, and glutamine. These characteristics of the HD cell transcriptome and metabolome may be important conditions for maintaining a long-living phenotype.