Simulated heat waves affect cell fate and fitness in the social amoeba Dictyostelium discoideum

Rivero Crespo, Francisco; Wollenberg-Valero, Katharina; Banu, Sarena

Abstract

The effects of heatwaves at organism and population levels have been widely investigated; however, little is known about how they affect the development of cell populations and the fitness of the resulting organism. Disruptions caused by heatwaves are especially critical during early developmental stages in organisms lacking parental developmental protection or care. Here we use the social amoeba Dictyostelium discoideum, a soil microbe with a life cycle that transitions between single-cell and multicellular stages. D. discoideum thrives optimally at 22°C and elevated temperatures impair (27°C) or completely arrest (30°) growth, development and spore yield. We established a simulated heatwave model in which vegetative cells were exposed to 27°C for 3 days and studied the effects on the expression of early and cell type specific developmental genes using real time quantitative PCR. A single heatwave severely impaired the expression of cyclic AMP-dependent early developmental gene markers (carA, acaA, pkaR, gtaC, tgrC1 and csaA) as well as that of prespore markers (cotB and spiA), while the expression of the prestalk marker ecmA was less affected. When mixed with heat-stressed cells, reporter cells expressing β-galactosidase grown at 22°C preferentially occupy the spore mass of the fruiting body. Chimera assays of wild type and reporter cells grown at optimal temperature or subjected to a heatwave confirmed a decreased fitness (contribution to chimeric fruiting bodies). We conclude that exposure of unprotected organisms at the single cell stage to a single heatwave has the potential to negatively impact their ability to cope with environmental extremes.

Citation

Rivero Crespo, F., Wollenberg-Valero, K., & Banu, S. (2025). Simulated heat waves affect cell fate and fitness in the social amoeba Dictyostelium discoideum. Microbial Ecology, 88, Article 21. https://doi.org/10.1007/s00248-025-02519-y

• Journal Article Type: Article
• Acceptance Date: Mar 25, 2025
• Online Publication Date: Apr 1, 2025
• Publication Date: Apr 1, 2025
• Deposit Date: Mar 25, 2025
• Publicly Available Date: Apr 3, 2025
• Journal: Microbial Ecology
• Print ISSN: 0095-3628
• Electronic ISSN: 1432-184X
• Publisher: Springer
• Peer Reviewed: Peer Reviewed
• Volume: 88
• Article Number: 21
• DOI: https://doi.org/10.1007/s00248-025-02519-y
• Keywords: heatwave, heat stress, Dictyostelium, fitness, development, spore yield
• Public URL: https://hull-repository.worktribe.com/output/5088477