Figure 4.

The interaction between apoptosis and mechanical force. (A) Apoptosis-induced morphogenetic changes in Drosophila leg joint formation. Apoptotic cells pull their neighbors toward the basal side during delamination at the presumptive joint area. In their neighboring cells, the actomyosin cable accumulates in the apical cortical area. The apical surface of surrounding cells undergoes apical constriction; (B) Model for mechanical tension-induced cell competition. In cultured mammalian epithelial cells, compaction by overcrowding induces apoptosis in polarity-deficient cells, which is mediated by the upregulation of p53. The yellow hexagons represent normal cells.