Decoding whole genome doubling: Insights from evolution, development and disease

Whole genome doubling (WGD) leading to physiological polyploidy, which is the presence of more than two copies of the whole chromosome set, is a common phenomenon observed in plants and animals. This natural occurrence serves various purposes in different organisms. For example, certain cells within specialized organs or tissues undergo genome doubling to enhance metabolic activity. In mammals, megakaryocytes exemplify this as they produce proteins and RNAs to form anucleated platelets. Polyploidization can also provide barrier functions, as seen in Drosophila sub-peripheral glia. Whole genome doubling is considered a major driving force in plant evolution, as polyploid plants often show a competitive advantage over diploid individuals.

However, unscheduled WGD can have detrimental consequences for the organisms, such as in the context of human cancers. The occurrence of WGDs is believed to contribute to the rapid evolution of the cancer genome by favoring chromosomal instability and thus enabling the selection of advantageous karyotypes. Recent progress in the field underscores the transformative nature of WGD and opens new avenues to gain understanding of the mechanistic basis of the processes triggered by WGD in cancer and evolution.

Although the study of WGD and polyploidy in vivo encompasses a range of model systems, from yeast to multicellular organisms like plants, Drosophila, Xenopus, and mice, the field remains relatively small and lacks a shared platform for scientific exchange and collaboration. Existing meetings focus primarily on physiological polyploidy in specific model organisms, resulting in a fundamental divide between researchers working on WGD in plants and those studying other organisms. This meeting aims to bridge this gap by bringing together experts from diverse fields, encompassing the physiological and non-physiological aspects of polyploidy, from yeast through plants to humans. By contrasting and overlapping findings, we will enhance our understanding of polyploidy as both a developmental choice and a contributor to genetic instability and cancer.