ESPCI web site
Pr Sander Tans, AMOLF (Delf University)
Organoids have emerged as an important tool to study tissue renewal. However, as methods to visualize the underlying cellular differentiation dynamics are lacking, key organizational principles remain unresolved. Here, we combine AI-enabled cell tracking with multiplexed endpoint antibody staining to show when and where cells differentiate in intestinal organoids, as well as correlations with their movement and genealogy. Notably, cells that ultimately differentiate and migrate to the villus region committed to their new type already deep inside the crypt – when still surrounded by their relatives that remain stem cells at the crypt bottom. Unexpected consequences of this early commitment are : 1) Secretory cells commit even before terminal division, causing secretory fates to emerge symmetrically in sister cells. 2) The relative abundances of secretory and absorptive cells is controlled mainly by proliferation after commitment. 3) Spatial patterning is achieved after commitment by type-dependent cell movement and rearrangements. This ‘commit-then-sort’ model contrasts with the idea that cells only commit after moving away from the crypt and into the transit amplifying region, and raises new questions about underlying commitment and sorting mechanisms. It may also be generally relevant, as the tissue architecture and molecular pathways are conserved in diverse stem cell systems. Our approach can be used widely for diverse organoid systems and combined with live-cell imaging.