The limb bud is of paradigmatic value to understanding vertebrate organogenesis. Recent
genetic analysis in mice has revealed the existence of a largely self-regulatory limb bud …

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 early window of human embryogenesis is largely a black box for developmental
biologists. Here we probed the cellular diversity of 4–6 week human embryos when …

Morphogenesis depends on the precise control of basic cellular processes such as cell
proliferation and differentiation. Wnt5a may regulate these processes since it is expressed in …

The zone of polarizing activity (ZPA) in the posterior limb bud produces Sonic Hedgehog
(Shh) protein, which plays a critical role in establishing distinct fates along the anterior …

To determine the role of fibroblast growth factor (FGF) signalling from the apical ectodermal
ridge (AER), we inactivated Fgf4 and Fgf8 in AER cells or their precursors at different stages …

The exquisitely beautiful form of a developing embryo is the result of a coordination between
the driving forces of morphogenesis and the processes of cell growth, proliferation …

''Fibroblast growth factor''(FGF) was first identified 25 years ago as a mitogenic activity in
pituitary extracts (Armelin 1973; Gospodarowicz 1974). This modest observation …

Limb development has long served as a model system for coordinated spatial patterning of
progenitor cells. Here, we identify a population of naive limb progenitors and show that they …

Exogenous retinoic acid (RA) induces marked effects on limb patterning, but the precise role
of endogenous RA in this process has remained unknown. We have studied the role of RA …