First published online July 19, 2004
Development 131, 1501e (2004)
© The Company of Biologists Limited
Smad4: not always essential for Tgfß signalling
Signalling through transforming growth factor ß (Tgfß)
superfamily members is important throughout vertebrate development, and Smad4
is generally regarded as a key intracellular effector of all Tgfß-related
signals. Surprisingly, Chu and colleagues now report that Smad4 is required
for only a subset of Tgfß-related signals during early mouse development
(see p. 3501). By
using a Smad4 conditional allele to inactive the Smad4 gene
in the early epiblast, they show that the primary anteroposterior axis is
established and gastrulation initiated in the absence of Smad4. Similarly,
many bone morphogenetic protein (Bmp) and Tgfß-regulated processes
involved in mesoderm formation and patterning are relatively unaffected.
However, anterior primitive streak derivatives fail to form. The researchers
conclude that Smad4 is essential for the Nodal signalling pathway that
specifies the anterior primitive streak, but is dispensable for the
transduction of some Bmp signals during early development.
Related articles in Development:
- Differential requirements for Smad4 in TGFß-dependent patterning of the early mouse embryo
- Gerald C. Chu, N. Ray Dunn, Dorian C. Anderson, Leif Oxburgh, and Elizabeth J. Robertson
Development 2004 131: 3501-3512.
[Abstract]
[Full Text]
