DIAZOM

The project focuses on ancient Chaetoceros diatom resting spores revived from Antarctic marine sediment cores up to 10,000 years old, with the potential to reach even further back in time. Our recent unprecedented success in reviving these spores opens a unique opportunity to study genomic and physiological adaptations across evolutionary timescales in a living system. We will use advanced methodologies, including whole genome sequencing, spike-in transcriptomics and paleo Hi-C to investigate how the genome of these spores survived prolonged periods of dormancy and remain poised to reactivate. Cells will be revived from differently aged spores and their adaptive capacities to environmental stressors such as light, temperature, salinity, and nutrients will be assessed to gain insights into past climate conditions, based on paleomarker analyses of the same cores. The project's novelty lies in generating high-resolution genotype-phenotype-environment data from living organisms for the first time over millennial timescales. By integrating this genomic, physiological, and ecological data, we aim to improve our understanding of how a keystone marine species has historically adapted to environmental changes, which will aid efforts to forecast their future resilience in a region that is changing rapidly as a consequence of global climate change. This interdisciplinary approach, combining molecular biology, paleoceanography, and phytoplankton eco-physiology, will generate unprecedented insights into the long-term survival mechanisms of marine diatoms, and more generally how a eukaryotic genome can remain in a viable state for millennia.