Mechanical coupling of compartments drives polarity and patterning of mouse auditory epithelium

The information that drives morphogenesis depends not only on genetically encoded cellular properties, but also emerges from the interaction between these cell behaviours. This information is spatio-temporally implemented to make tissue shape and order robust and reproducible during development. What are the principles for organising this information? The mouse auditory epithelium, the organ of Corti (OC) is an excellent system to investigate this. A central domain senses sound information through mechanosensory hair cells (HC), part of a mosaic with supporting cells (SC). This is flanked by non-sensory domains. These domains undergo cellular rearrangements as they become ordered and elongate. How cellular properties are coordinated across domains and how these contribute to tissue shape is unknown. Here, we find adhesion codes, established through morphogen patterning, define OC domains as compartments. Cells in each compartment exhibit distinct patterns of ordering. By perturbing cellular rearrangements in individual compartments, we find that compartment-specific ordering can contribute to overall tissue architecture. Perturbation of cell order within a compartment also affects the organisation in another. Using vinculin mutants, we show that inter-compartment coupling is, in part, mechanical. Our work suggests that compartments and their coupling can organise morphogenetic information in space and time during organogenesis.