How do fingers grow and can they regenerate

Digits- fingers and toes, are segmental structures made up along their length by a series of small bones called phalanges, separated by synovial joints. While the number of digits which form during embryonic development is both highly conserved and a classical model to understand the general mechanisms of embryonic development, how fingers and toes actually grow out and segment is fundamentally unknown. Altered digit development is, however, the most common form of congenital hand or foot differences with important implications for welfare of people and animals. Brachydactyly, for example, in which phalanges are small or malformed is estimated to occur in up to 2% of human live births. Our digits also play an important role in accessing and manipulating our environment, but as most people know, this frequently leads to damage or even loss! A loss of a finger or toe, has profound functional consequences, especially as humans, like many vertebrates, have a very limited ability to regenerate their digits. This project aims, for the first time, to visualise digit outgrowth using ex-ovo imaging of chicken embryos expressing cartilage reporters, combined with computer visions analysis, to answer the question 'How does a finger grow?'.