Insights on the control of yeast single-cell growth variability by members of the Trehalose Phosphate Synthase (TPS) complex

Sevan Arabaciyan (1) , Michael Saint-Antoine (2) , Cathy Maugis-Rabusseau (3) , Jean Marie François (1) , Abhyudai Singh (4, 5) , Jean-Luc Parrou (1) , Jean-Pascal Capp (1)

1 TBI - Toulouse Biotechnology Institute
2 Department of Biomedical Engineering
3 IMT - Institut de Mathématiques de Toulouse UMR5219
4 Department of Biomedical Engineering
5 Department of Electrical and Computer Engineering

Single-cell variability of growth is a biological phenomenon that has attracted growing interest in recent years. Important progress has been made in the knowledge of the origin of cell-to-cell heterogeneity of growth, especially in microbial cells. To better understand the origins of such heterogeneity at the single-cell level, we developed a new methodological pipeline that coupled cytometry-based cell sorting with automatized microscopy and image analysis to score the growth rate of thousands of single cells. This allowed investigating the influence of the initial amount of proteins of interest on the subsequent growth of the microcolony. As a preliminary step to validate this experimental setup, we referred to previous findings in yeast where the expression level of Tsl1, a member of the Trehalose Phosphate Synthase (TPS) complex, negatively correlated with cell division rate. We unfortunately could not find any influence of the initial TSL1 expression level on the growth rate of the microcolonies.We also analyzed the effect of the natural variations of trehalose-6-phosphate synthase (TPS1) expression on cell-to-cell growth heterogeneity, but we did not find any correlation. However, due to the already known altered growth of the tps1 mutants, we tested this strain at the single-cell level on a permissive carbon source. This mutant showed an outstanding lack of reproducibility of growth rate distributions as compared to the wild-type strain, with variable proportions of non-growing cells between cultivations and more heterogeneous microcolonies in terms of individual growth rates. Interestingly, this variable behavior at the single-cell level was reminiscent to the high variability that is also stochastically suffered at the population level when cultivating this tps1 strain, even when using controlled bioreactors.

Mots clés: Saccharomyces cerevisiae; single-cell analysis; Stochastic gene expression; gene expression noise; phenotypic heterogeneity; TPS1; TSL1; stochastic gene expression

Domaines: Sciences du Vivant [q-bio]; Biotechnologies; Biologie moléculaire

Sevan Arabaciyan, Michael Saint-Antoine, Cathy Maugis-Rabusseau, Jean Marie François, Abhyudai Singh, et al.. Insights on the control of yeast single-cell growth variability by members of the Trehalose Phosphate Synthase (TPS) complex. Frontiers in Cell and Developmental Biology, 2021, Yeast Differentiation: From Cell-to-Cell Heterogeneity to Replicative Aging and Regulated Cell Death, 9, ⟨10.3389/fcell.2021.607628⟩. ⟨hal-03098577⟩