title: Mechanistic insight into how Shh patterns the vertebrate limb.
abstract: The hands and feet of a newborn baby are a beautiful reminder of the complexity of embryonic patterning. Classical studies on how these structures form have led to a theoretical framework for understanding, in general, how discrete groups of cells can instruct differential fates across a wider field through the action of long-range signals. The discovery just more than a decade ago that localized expression of Sonic hedgehog (Shh) differentially patterns structures across the limb field, resulting in digits with unique characteristics, provided a starting point for readdressing these models at a molecular level. Current research has revealed unexpected complexity in how a gradient of Shh activity is both established and received, prompting re-evaluation of the nature of patterning mechanisms within the limb.
authors.affiliation: Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA.
authors.forename: Edwina
authors.initials: E
authors.lastname: McGlinn
authors.forename: Clifford J
authors.initials: CJ
authors.lastname: Tabin
mesh_terms: D000818:Animals; D019521:Body Patterning; D002465:Cell Movement; D049109:Cell Proliferation; D005121:Extremities / Q000196:embryology*; D053823:Hedgehog Proteins; D006801:Humans; D018878:Limb Buds / Q000166:cytology / Q000196:embryology; D015398:Signal Transduction; D015534:Trans-Activators / Q000502:physiology*; D014714:Vertebrates / Q000196:embryology*
chemical_list: D053823:Hedgehog Proteins; C509239:SHH protein, human; D015534:Trans-Activators