PIF2024 - The origin of animals: a cell biological approach (PID2023-153273NB-I00)

The origin of multicellular animals from their unicellular ancestor represent one of the most important evolutionary transitions in the history of life. However, and despite its importance, the mechanisms underlying this transition remain largely elusive. Our laboratory is at the forefront of addressing this fundamental question. Over the past 15 years, we have advanced considerably on our quest to unravel how animals originated. We have unravelled who are the closest unicellular relatives of animals, got their genomes to infer the genetic composition of the unicellular ancestor of animals, and we even have established four species as emerging model systems to experimentally address questions about the origin of animals. Our research has shown that the unicellular ancestor of animals was much more complex than previously thought. That ancestor already had the genetic raw material to evolve into a multicellular organism. Our hypothesis is the unicellular ancestor had a highly phenotypic plasticity and the capacity to differentiate into many different cell stages. In this proposal, we aim to get additional data crucial to unravel the origin of animal cell types, and understanding the role of the phenotypic plasticity in transition towards a multicellular entity. We also aim to strengthen our experimental model systems so that we can create the best possible functional platform to analyze the origin of animals.