Mechanical Forces and Evolutionary Strategies in Tissue Development
The study reveals that the cephalic furrow (CF) in fly gastrulation is an evolutionary innovation in Cyclorrhapha that functions as a mechanical sink to prevent tissue collision and buckling during head and trunk expansion. In non-cyclorrhaphan flies, alternative strategies like out-of-plane cell division mitigate mechanical stress, highlighting divergent evolutionary adaptations to ensure robust morphogenesis. Loss of CF leads to tissue buckling and developmental defects, emphasizing its mechanical and developmental importance.