Preventing deformed limbs: researchers discover link to physical forces

University of Toronto engineers and a U of'T pediatric surgeon have discovered how physical forces such as pressure and tension affect the development of limbs in embryos - research that could someday be used to help prevent birth defects. The team, including U of'T bioengineer Rodrigo Fernandez-Gonzalez from the Institute of Biomaterials & Biomedical Engineering, U of'T mechanical engineer Yu Sun and the Faculty of Medicine's Dr. Sevan Hopyan used live imaging and computer models to study the links between mechanical forces, changes in cell shape and cell movement in embryos. Their study - published this week - used cutting-edge techniques to gain valuable insight into the fundamental processes of arm and leg development. Mapping-out the growth of 'proto-limbs' An embryo starts out shaped like a ball, then grows to create complex shapes like limbs. In early embryonic development, cells divide into three layers: the ectoderm, which forms the nervous system, skin and sensory organs; the mesoderm, which produces the skeleton, muscles and most of the major organs; and the endoderm, which turns into the body's respiratory tract and elimination systems. In the study, the team looked at cell behaviours in the ectoderm that promote limb development. They used unique tools, including micro-chiseling ablating lasers, atomic force microscopes and layer-by-layer computer models, to explore the early stages of limbs in unprecedented detail.