Heat shock drives genomic instability and phenotypic variations in yeast

Abstract

High temperature causes ubiquitous environmental stress to microorganisms, but studies have not fully explained whether and to what extent heat shock would affect genome stability. Hence, this study explored heat-shockinduced genomic alterations in the yeast Saccharomyces cerevisiae. Using genetic screening systems and customized single nucleotide polymorphism (SNP) microarrays, we found that heat shock (52 °C) for several minutes could heighten mitotic recombination by at least one order of magnitude. More than half of heat-shock-induced mitotic recombinations were likely to be initiated by DNA breaks in the S/G 2 phase of the cell cycle. Chromosomal aberration, mainly trisomy, was elevated hundreds of times in heat-shock-treated cells than in untreated cells. Distinct chromosomal instability patterns were also observed between heat-treated and carbendazim-treated yeast cells. Finally, we demonstrated that heat shock stimulates fast phenotypic evolutions (such as tolerance to ethanol, vanillin, fluconazole, and tunicamycin) in the yeast population. This study not only provided novel insights into the effect of temperature fluctuations on genomic integrity but also developed a simple protocol to generate an aneuploidy mutant of yeast.

The adaptive roles of aneuploidy and polyclonality in Leishmania in response to environmental stress

“…In conclusion, our data support the role of mosaic aneuploidy in generating multiple pre‐adapted karyotypes that can be further modulated de novo during drug exposure. This process might depend on the nature and strength of the drug‐associated stress and might be potentiated by a stress‐induced increase in chromosome instability as seen in other organisms (Chen et al , 2012 ; Tan et al , 2019 ; Shen et al , 2020 ). Further research with longitudinal SCGS combined with lineage tracing is needed in order to validate these hypotheses.…”

Heat Shock Factor 1 forms nuclear condensates and restructures the yeast genome before activating target genes

“…As mentioned above, the temporary effect on chromatin could suppress Pol II recruitment and subsequent elongation. Possible advantages of this chromatin compaction could be to downregulate global transcription, as well as to limit the chromatin damage by reactive oxygen species or other potentially damaging molecules present in the cell during stress conditions (Bradley et al, 2021; Costa et al, 1997; Davidson et al, 1996; Davidson & Schiestl, 2001; Shen et al, 2020; Voordeckers et al, 2020).…”

Engineering natural isolates of Saccharomyces cerevisiae for consolidated bioprocessing of cellulosic feedstocks

“…The extent of the metabolic burden in recombinant cellulase producing strains is dependent on various factors, such as gene copy number, source of the gene, expression strategy (i.e., secretion, cell-attachment, mini-cellulosomes, and/or combinations), oxygen availability, and the strain background. In addition, changes in the physical environment (temperature, pH, nutrients, solutes, and inhibitors) also contribute significantly to the viability of cells and the resulting heterologous protein production process (Brandt et al 2021 ; Shen et al 2020 ). We therefore investigated heterologous cellulase production in various strain backgrounds, previously shown to be robust to various CBP related stress factors, to determine how process relevant changes in the environment, which impact these strains differently, affected their ability to secrete recombinant enzymes and convert crystalline cellulose to ethanol.…”