The gene encoding the secreted protein Sonic hedgehog (Shh) is expressed in the
polarizing region (or zone of polarizing activity), a small group of mesenchyme cells at the …

The potential role of Hox genes during vertebrate limb development was brought into focus
by gene expression analyses in mice (P Dolle, JC Izpisua-Belmonte, H Falkenstein, A …

Abstract Vertebrate HoxA and HoxD cluster genes are required for proper limb
development,,. However, early lethality, compensation and redundancy have made a full …

Anterior-to-posterior patterning, the process whereby our digits are differently shaped, is a
key aspect of limb development. It depends on the localized expression in posterior limb bud …

The vertebrate limb is an excellent model for studying fundamental aspects of embryonic
development. Cell proliferation, death and movement, and the assignment and interpretation …

In the classical model of chick wing digit-patterning, the polarizing region—a group of cells
at the posterior margin of the early bud—produces a morphogen gradient, now known to be …

The vertebrate limb continues to serve as an influential model of growth, morphogenesis
and pattern formation. With this Review, we aim to give an up-to-date picture of how a …

The developing limb has been a very influential system for studying pattern formation in
vertebrates. In the past, classical embryological models have explained how patterned …

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 …

The zone of polarizing activity is the primary signaling center controlling anterior–posterior
patterning of the amniote limb bud. The autopodial interdigits (IDs) are secondary signaling …