The zone of polarizing activity (ZPA) is an area of mesenchyme that contains signals which instruct the developing limb bud to form along the anterior/posterior axis. Limb bud is …

A-P patterning is established by the Zone of Polarizing Activity (ZPA) on the posterior side of the limb (i.e. the little finger side). Shh signaling from the ZPA specifically signals the formation of …

Two key signalling centres drive vertebrate limb development: the apical ectodermal ridge (AER) and the zone of polarising activity (ZPA). Embryological manipulations of the chick limb bud …

Among John Saunders’ many seminal contributions to developmental biology, his discovery of the limb ‘zone of polarizing activity’ (ZPA) is arguably one of the most memorable and ground …

The second signaling center is the zone of polarizing activity (ZPA), which is a group of limb mesenchymal cells formed at the posterior margin of the limb bud. The polarizing activities of …

The zone of polarizing activity (ZPA) corresponds to a group of cells located in the posterior mesenchyme of the limb bud that act as an organizer of the AP polarity of the limb (Figure 10 …

In 1993, Riddle and colleagues showed by in situ hybridization that sonic hedgehog (shh), a vertebrate homologue of the Drosophila hedgehog gene, was expressed specifically in that …

1993年12月31日 · The zone of polarizing activity (ZPA) is a region at the posterior margin of the limb bud that induces mirror-image duplications when grafted to the anterior of a second limb. …

John W. Saunders, Jr. made seminal discoveries unveiling how chick embryos develop their limbs. He discovered the apical ectodermal ridge (AER), the zone of polarizing activity (ZPA), …

2017年9月15日 · John W. Saunders' pioneering work established the limb as a key model for developmental patterning. Saunders' discovery of the Zone of Polarizing Activity (ZPA) …