Interkinetic nuclear movements promote apical expansion in pseudostratified epithelia at the expense of apicobasal elongation
Fig 3
INM opposes apicobasal elongation, generates apical nuclear crowding and enlarges the apical domain.
Simulations with passive apical-apical springs with INM (black and brown curves) or without INM (red curves) with constant cell number (see S2 Movie). A, Apicobasal length of the PSE (AB) and mean nuclear position along the AB axis, expressed in micrometers. Note that INM reduce apicobasal length (black curve with open circles (INM) is below the red curve (no INM)) and generate apical nuclear crowding (black curve with closed circles (INM) is above the red curve (no INM)). B, Number of layers 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, Position of mitoses along AB axis, 1 being apical. E-F, net width of apical (magenta), nuclear (black) and basal (cyan) domains of the PSE over time. For each domain, the distance the between the first and last point along the lateral axis is computed and its evolution plotted over time. Note that INM promote enlargement of the apical domain (panel 3G, arrow). 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. Box and whiskers plot: the box extends from the 25th to the 75th percentile; the whiskers show the extent of the whole dataset. The median is plotted as a line inside the box.