Interkinetic nuclear movements promote apical expansion in pseudostratified epithelia at the expense of apicobasal elongation
Fig 5
Increase in cell number drives pseudostratification and apical contractility feeds back into basal rearrangements.
Simulations with passive or contractile apical springs, normal INM and various rates of exclusion of daughter cells (see S3 Movie). A, apicobasal length of the PSE (AB) and mean nuclear position along the AB axis (N) over time expressed in micrometers. B, Number of pseudolayers of nuclei along the AB axis. C, straightness of apical domain (net distance between the first and last apical point divided by the actual distance between these two points). D-F, net width of apical (magenta), nuclear (black) and basal (cyan) domains of the PSE with passive apical-apical springs over time with 50 (D), 40 (E) and 30% (F) of daughter cells being excluded from the 2D plane. G-I, net width of apical (magenta), nuclear (black) and basal (cyan) domains of the PSE with contractile apical-apical springs over time with 50 (G), 40 (H) and 30% (I) of daughter cells being excluded from the 2D plane. For each domain, the distance between the first and last point along the lateral axis is computed and its evolution plotted over time. Note that apical contractility leads to basal rearrangements (compare cyan curves in H-I grow faster than in E-F). Each simulation was performed over 480 iterations (48h of biological time) for 10 repetitions. Each curve represents the mean value of each dataset for the parameter plotted.