First published online August 24, 2007
Development 134, 1801e (2007)
© The Company of Biologists Limited
Why mice have muzzles and birds have beaks
Although the faces of vertebrate embryos look remarkably similar at early
stages of development, they rapidly adopt species-specific characteristics.
But how is regional specification of the face achieved? The answer, suggest
Brugmann and colleagues on p.
3283, is Wnt signalling. Using transgenic Wnt reporter embryos, the
researchers show that domains of Wnt-responsive cells in the developing mouse
face correspond to the facial prominences (for example, the characteristic
muzzle) that develop later. These domains of Wnt responsiveness, the
researchers note, generally coincide with areas where there is marked cell
proliferation. Furthermore, they report, genetic or biochemical disruption of
Wnt signalling in mouse embryos produces animals with unusually wide-set eyes
and flattened midfaces. Similar investigations in chick embryos reveal that
Wnt signalling is an evolutionarily conserved mechanism that determines facial
features by regulating differential craniofacial growth. In other words, the
radically different facial features of vertebrates might all be explained by
species-specific, regional variations in Wnt signalling during craniofacial
development.
Related articles in Development:
- Wnt signaling mediates regional specification in the vertebrate face
- Samantha A. Brugmann, L. Henry Goodnough, Alex Gregorieff, Philipp Leucht, Derk ten Berge, Christophe Fuerer, Hans Clevers, Roel Nusse, and Jill A. Helms
Development 2007 134: 3283-3295.
[Abstract]
[Full Text]
