Abstract

In developing pseudostratified epithelia, nuclei move repeatedly between the apical and basal surfaces of cells. This process is termed interkinetic nuclear migration (IKNM) and has been studied extensively in the brain, retina and spinal cord of multiple organisms. But despite these efforts many questions about the precise mechanism of IKNM remain. Based on in vivo light sheet microscopy we develop a quantitative model for the phenomenological properties of IKNM in the retinal system. Both the data and our model support the hypothesis of IKNM being a stochastic process during the majority of the cell cycle. Furthermore, our model reveals the remarkable and previously overlooked importance of simple physical constraints imposed by the overall tissue architecture. Because IKNM has been suggested to fulfil a regulatory role for retinal cell differentiation, our results have important implications for understanding proper eye development. Moreover, our findings will inform future work on IKNM in other organs and on the developmental regulation in these systems.