Interkinetic nuclear movements promote apical expansion in pseudostratified epithelia at the expense of apicobasal elongation

Overview & Synopsis

17 Pseudostratified epithelia (PSE) are a common type of columnar epithelia found in a wealth of 18 embryonic and adult tissues such as ectodermal placodes, the trachea, the ureter, the gut and 19 the neuroepithelium. PSE are characterized by the choreographed displacement of cells' 20 nuclei along the apicobasal axis according to phases of their cell cycle. Such movements, 21 called interkinetic movements (INM) have been proposed to influence tissue expansion and 22 shape and suggested as culprit in several congenital diseases such as CAKUT and esophageal 23 atresia. INM rely on cytoskeleton dynamics just as adhesion, contractility and mitosis do. 24 Therefore, longer term impairment of INM without affecting proliferation and adhesion is 25 currently technically unachievable. Here we bypassed this hurdle by generating a 2D agent-26 based model of a proliferating PSE and compared its output to the growth of the chick 27 neuroepithelium to assess the interplay between INM and these other important cell 28 processes during growth of a PSE. We found that INM directly generates apical expansion and