Collective mechanics of embryogenesis: Formation of ventral furrow in   Drosophila
  We propose a 2D mechanical model of the ventral furrow formation in Drosophila that is based on undifferentiated epithelial cells of identical properties whose energy resides in their membrane. Depending on the relative tensions of the apical, basal, and lateral sides, the minimal-energy states of the embryo cross-section includes circular, elliptical, biconcave, and buckled furrow shapes. We discuss the possible shape transformation consistent with reported experimental observations, arguing that generic collective mechanics may play an important role in the embryonic development in Drosophila. 
A. Hocevar and P. Ziherl
q-bio.CB cond-mat.soft physics.bio-ph