Abstract:
The study of ‘programmed’ forms cell death, was for a long time, confined to macroscopic organisms, predominantly plants and animals. Microbial cell death was usually attributed to aging and predation, so when analogous forms of PCD were identified in the microbial world in the late 1900s, it was viewed more as a curiosity than an evolved biological function. But in the last two to three decades the field of unicellular death has been transformed by the evidence that microbial cell death can offer evolutionary advantages and is a feature across the tree of life. In this seminar I will cover the key parts of this transformation and its relevance for extra-terrestrial habitability. Briefly, the history of cell death studies (PCD in particular) is discussed, followed by the challenges that the changing landscape of microbial death poses for the paradigm of PCD. The change in our understanding of microbial cell death is relevant for a wide range of fields, from mechanistic disciplines in biology, to more specialized areas relating to infectious diseases, cancer, microbial ecology, biotechnology, climate change, and astrobiology. I will cover some of the main topics in microbial PCD, for example, the mechanisms, their evolution, and the role of PCD in nature. I will dedicate almost a third of the seminar to microbial cell death in astrobiology focussing on (1) the origin of cell death in the Archaean era, (2) the importance of microbial cell death in current space travel programs and the aim of establishing a viable colony of extraterrestrial algal or yeast cells, and (3) what our current knowledge of microbial cell death tells us about the search for extraterrestrial life, and habitability on exoplanets.
References
1. Jodder, J. et al. The Archaean record of the Singhbhum Craton – a new window into early life on Earth. In: Homann, M., et al. (Eds). The Precambrian Earth: Tempos and Events. Elsevier. (Publication imminent, 2024).
2. Durand, PM. 2021. The evolutionary origins of life and death. University of Chicago Press: Chicago, USA.
3. Hardwick, J.M. and Durand, P.M (Eds). A New Era of Microbial Cell Death. Sringer Nature. Expected January 2025.