Distribution of neurosensory progenitor pools during inner ear morphogenesis unveiled by cell lineage reconstruction

Reconstructing the lineage of cells is central to understanding how the wide diversity of cell types develops. Here, we provide the neurosensory lineage reconstruction of a complex sensory organ, the inner ear, by imaging zebrafish embryos in vivo over an extended timespan, combining cell tracing and cell fate marker expression over time. We deliver the first dynamic map of early neuronal and sensory progenitor pools in the whole otic vesicle. It highlights the remodeling of the neuronal progenitor domain upon neuroblast delamination, and reveals that the order and place of neuroblasts' delamination from the otic epithelium prefigure their position within the SAG. Sensory and non-sensory domains harbor different proliferative activity contributing distinctly to the overall growth of the structure. Therefore, the otic vesicle case exemplifies a generic morphogenetic process where spatial and temporal cues regulate cell fate and functional organization of the rudiment of the definitive organ.This work was supported from Spanish Ministry of Economy and Competitiveness (MINECO) by Grant BFU2012-31994 to CP, Unidad de Excelencia María de Maetzu 2015–19 MDM-2014–0370 to DCEXS-UPF, Centro de Excelencia Severo Ochoa 2013–17, SEV-2012–0208 and Swiss National Science Foundation (SINERGIA CRSII3 141918) to CRG. BioEmergences services were funded by ANR-10-INBS-04 and ANR-11-EQPX-0029. SD and AZ were recipients of predoctoral FI-fellowships from AGAUR (Generalitat de Catalunya). CP is recipient of an ICREA Academia award (Generalitat de Catalunya