Oscillatory cortical forces promote three dimensional cell intercalations that shape the mandibular arch

Abstract

Multiple vertebrate embryonic structures such as organ primordia are composed of a volume of confluent cells. Although mechanisms that shape tissue sheets are increasingly understood, those which shape a volume of cells remain obscure. Here we show 3D mesenchymal cell intercalations, rather than cell divisions and biophysical tissue properties, are essential to shape the mandibular arch of the mouse embryo.Using a genetically encoded vinculin tension sensor, we show that cortical force oscillations promote these intercalations. Genetic loss and gain of function approaches show that Wnt5a functions as a spatial cue to coordinate cell polarity with cytoskeletal oscillation. YAP/TAZ and PIEZO1 serve as downstream effectors of Wnt5a-mediated actomyosin bias and cytosolic calcium transients, respectively, to ensure appropriate tissue form during growth. Our data support oriented 3D cell neighbour exchange as a conserved mechanism driving volumetric morphogenesis.

Nanoscale Ligand Density Modulates Gap Junction Intercellular Communication of Cell Condensates During Chondrogenesis

“…Inhibition of myosin-2 activity can cause a decrease in cortical tension of up to 80% [47]. Treatment of 6day condensates with the myosin-2 inhibitor blebbistatin decreased the percentage of area immunostained for Cx43 of S 90 condensates (Fig.…”

“…Cortical actin assembly can be observed in early mesenchymal condensates [30]. Cortical tension gradients are responsible for mesenchymal cell rearrangement during tissue formation and are essential in driving tissue morphogenesis [46,47]. The cell cortex is formed by an actomyosin network, which is located below the cell membrane.…”