Actomyosin-based force generation sculpts tissues into a remarkable array of shapes during
development. Successful tissue sculpting requires that actomyosin is precisely regulated and that the
resulting force patterns are transmitted across the tissue. Force transmission itself affects contractile
signaling, resulting in emergent behaviors that result in tissue shape change.
We have demonstrated the role of dynamic RhoA-GTPase cycling in generating actomyosin
pulses and waves in Drosophila gastrulation and oogenesis, respectively. In each of these cases, we
identified a Rho GTPase activating protein (RhoGAP) that is required for cycling behavior and
demonstrates the functional importance for the cycling in morphogenesis. Our work has demonstrated
the requirement of RhoGTPase cycling in tissue invagination and the completion of cytoplasmic
transport from germline support cells to the oocyte. The mechanisms that initiate these dynamic
behaviors and how they are influenced by force transmission in a tissue are still unknown.
Patterns of force transmission in a tissue are complex and extremely dynamic. We have
identified the importance of supracellular actomyosin meshworks in transmitting forces between
hundreds of cells in a tissue, which forms chains of mechanically interconnected cells. Supracellular
actomyosin meshworks within epithelia can exhibit biased connections, which influence tissue
mechanics. But, how a cell determines which neighbors to link to is unknown and critical to understand
tissue shape. Furthermore, the cell biological mechanisms that dissipate forces in response to
morphogenetic movements and how they are coordinated with movement are poorly understood.
We will undertake a multidisciplinary and multiscale approach to understand tissue shape
emergence. Combining our ability to visualize and perturb dynamic signaling pathways we will
investigate the interconnection between forces `felt' by cells and resulting single cell signaling patterns
with the goal of bridging molecular and tissue scales. Members of my lab include biologists, physicists,
and engineers. In addition, we have excellent collaborators in Mathematics to supplement our research
capabilities. We are poised to make additional important contributions to our understanding of how
collective cell behaviors contribute to morphogenesis.