Abstract

The self-organisation of cells during the development and maintenance of tissues is one of the most intriguing non-equilibrium processes in nature. How do stem and progenitor cells coordinate their behaviour in order to build a complex structure like a living organism? In recent years lineage tracing experiments have become increasingly successful in unveiling stem cell behaviour in adult tissues. However, in development and tumour growth its application remains a major problem. Due to cell dispersal or mechanical deformations labelled clones often fragment or merge, making the retrospective analysis of lineages highly ambiguous. What can we learn from lineage tracing experiments in developing tissues?

Using the example of mammalian heart development we explore whether and how information on cell fate behaviour can be recovered from the analysis of lineage tracing assays in developing tissues. By formally mapping the clonal dynamics to the theory of aerosols and employing renormalisation group methods we show that fragmentation and merging lead to universal scaling distributions, compromising and even erasing information on cell fate behaviour. As well as providing a framework for distilling cell fate-specific information from universal dependences at long times, this study serves as a paradigm for how the cellular dynamics of living tissues provides a laboratory for statistical physics.