First published online March 30, 2004
Development 131, 801e (2004)
© The Company of Biologists Limited
An embryological double act
Members of the transforming growth factor ß (TGFß) family of
secreted growth factors regulate many embryonic processes. Now, Dunn et al.
report (p. 1717) that
Smad2 and Smad3, two closely related intracellular effectors of the
TGFß/activin/Nodal receptors, signal cooperatively in a dose-dependent
manner to regulate mesoderm formation and patterning in the early mouse
embryo. Although Smad2 and Smad3 are often functionally interchangeable, the
development of mice lacking Smad2 is severely disrupted, whereas
Smad3-deficient mice have only subtle abnormalities. When the
researchers genetically manipulated the expression ratio of Smad2 and Smad3,
embryos with only one copy of each gene developed normally but loss of
Smad3 in the context of one wild-type copy of Smad2 resulted
in impaired production of anterior mesendoderm. Smad2;Smad3 double
homozygous mutants entirely lacked mesoderm and failed to gastrulate. This
provides the first evidence that Smad3 is essential during early
post-implantation mouse development.
Related articles in Development:
- Combinatorial activities of Smad2 and Smad3 regulate mesoderm formation and patterning in the mouse embryo
- N. Ray Dunn, Stéphane D. Vincent, Leif Oxburgh, Elizabeth J. Robertson, and Elizabeth K. Bikoff
Development 2004 131: 1717-1728.
[Abstract]
[Full Text]
