RT Journal Article
SR Electronic
T1 Actomyosin pulsing rescues embryonic tissue folding from disruption by myosin fluctuations
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2023.03.16.533016
DO 10.1101/2023.03.16.533016
A1 Hongkang Zhu
A1 Ben O’Shaughnessy
YR 2023
UL http://biorxiv.org/content/early/2023/03/18/2023.03.16.533016.abstract
AB During early development, myosin II mechanically reshapes and folds embryo tissue. A much-studied example is ventral furrow formation in Drosophila, marking the onset of gastrulation. Furrowing is driven by contraction of actomyosin networks on apical cell surfaces, but how the myosin patterning encodes tissue shape is unclear, and elastic models failed to reproduce essential features of experimental cell contraction profiles. The myosin patterning exhibits substantial cell-to-cell fluctuations with pulsatile time-dependence, a striking but unexplained feature of morphogenesis in many organisms. Here, using biophysical modeling we find viscous forces offer the principle resistance to actomyosin-driven apical constriction. In consequence, tissue shape is encoded in the direction-dependent curvature of the myosin patterning which orients an anterior-posterior furrow. Tissue contraction is highly sensitive to cell-to-cell myosin fluctuations, explaining furrowing failure in genetically perturbed embryos whose fluctuations are temporally persistent. In wild-type embryos, this catastrophic outcome is averted by pulsatile myosin time-dependence, a time-averaging effect that rescues furrowing. This low pass filter mechanism may underlie the usage of actomyosin pulsing in diverse morphogenetic processes across many organisms.Competing Interest StatementThe authors have declared no competing interest.