Robustness Of Body Axis Symmetry through Tissue Mechanics in Amniote Embryos

How embryos keep their fast-growing body axis straight to avert developmental defects such as scoliosis remains unclear. This question exemplifies the delicate balance between the stability of shape and the flexibility of deformation, that developing tissues must achieve through mechanical regulation. Using novel precision tools in avian embryos, my lab recently discovered a resisting and restoring force to body axis bending originated from the paraxial tissues. We also identified an anterior-to-posterior mechanical property gradient underpinned by the extracellular matrix that favours symmetric elongation. Consolidating these advances with a closely-knit collaborative network, we will decipher the regulatory mechanisms of body axis symmetry through 3 Aims: 1) Understand the tissue stresses and mechanical patterns that enforce symmetric elongation of the avian body axis using Tissue Force Microscopy and nanorobotics, 2) Elucidate the roles and regulation of extracellular matrix and cell organization in driving tissue mechanics, and 3) Uncover principles of body symmetry through computational modelling and comparative analyses of stem-cell-derived human posterior organoids. Our work will provide cross-scale mechanistic understanding of amniote posterior body development, shedding light on fundamental principles of inter-tissue mechanics in morphogenesis. Our new quantitative technical platforms will be broadly applicable for in vivo tissue mechanics in other systems.