A combination of embryology and gene identification has led us to the current view of vertebrate limb development, in which a series of three interlocking patterning systems operate sequentially over time. This review describes current understanding of these regulatory mechanisms and how they form a framework for future analysis of limb patterning.
Tickle, C. A. (2003, April 1). Patterning systems - From one end of the limb to the other. Developmental Cell. https://doi.org/10.1016/S1534-5807(03)00095-9