Redundancy in a supracellular actomyosin networks yields robust tissue folding

Correct tissue shape is essential proper tissue function. In many developing systems myosin-driven contractions are harnessed to fold cell monolayers and sculpt shape. For example folding forms both the vertebrate eye and the neural tube. In Drosophila, a cell monolayer on the ventral side of the embryo undergoes myosin-dependent constriction to fold the tissue internalizing presumptive mesoderm cells. The ventral furrow establishes a supracellular network of contractile actin-myosin fibers just prior to folding. While the cytoskeletal organization and mechanism of contraction in a single cell is understood, less is known about how the cytoskeleton is patterned across the tissue to achieve robust folding. We have integrated concepts from topological feature analysis to map the connectivity of the previously unquantified network spanning hundreds of cells. Our framework allows us to explore stereotypic properties of the supracellular network and investigate the need for reproducibility its of mechanical connections. We apply both mechanical and genetic perturbations to degrade the network and have identified that there exists multiple network architectures that induce folding. Additionally, we demonstrate the importance of redundant connections in ensuring the folding robustness.