Polyploidy, i.e. the possession of multiple sets of chromosomes because of whole-genome duplication (WGD), has been known for a long time, especially in plants. For a long time, ancient polyploidy, dating back millions of years, was much less well documented and it was not until the advent of genomics and whole genome sequencing that it became clear that the significance of polyploidy extends across all eukaryotes, from ancient history to the recent past. Because of their often-enhanced phenotypic appearance, polyploidy has also been a key force in the origin and success of most crops. Artificial polyploidization of crops can increase yield and specific nutrients, thereby improving food security, a critical goal given the Earth’s expanding population and limited arable land. In addition to occurring in whole organisms, programmed or unprogrammed events can increase the ploidy of specific somatic cells and cell lineages. In humans, polyploid cells keep the human heart beating, and are essential for repair of the liver. Polyploid cells are important in the development of structures including trichomes, fruits, and root nodules. Acute, induced polyploidy in individual cells or tissues can also occur in response to tissue stress and in disease. Finally, unprogrammed ploidy increases are now known to be among the most common events in human tumor growth. In conclusion, polyploidy is a driving force in organismal and sub-organismal evolution and elucidating the consequences of WGD at multiple levels is key to understanding global patterns of biodiversity and ecology, as well as cellular fates, physiology, and metabolism. Although the implications of polyploidy range from cells to ecosystems and from agriculture to human health, polyploidy remains understudied in many contexts, and its roles and impact in biological processes and across phylogeny are unclear.
One recurring theme is the link between polyploidy and stress. It is known that stress can trigger polyploidy, but there are also strong indications that polyploidy confers a selective advantage under stressful conditions, such as during environmental turmoil. In this research project, we want to build on our current expertise in polyploidy and WGD by unraveling the mechanistic complexities underlying polyploidy under stressful conditions. To this end, we want to use a holistic interdisciplinary approach integrating genomics, experimental evolution, modeling, and Artificial Intelligence (AI).
