First published online September 9, 2005
Development 132, 1901e (2005)
© The Company of Biologists Limited
Zoning in on the stem zone
The spinal cord in vertebrates is generated from the stem zone, a poorly
characterized population of epiblast cells at the caudal end of the developing
neural plate. On p.
4273, Delfino-Machín et al. describe this important cell
population and the signalling pathways that specify it. They report that many
cells in the chick stem zone express both early neural and mesodermal genes,
but that this ambivalent cell fate is not a prerequisite for stem
zone-specific gene expression. They show that FGF signalling is required but
not sufficient for stem zone specification - signals from the paraxial
mesoderm are also required. FGF signalling is also necessary for the onset of
caudal Hox gene expression, but neither process requires retinoid signalling.
Thus, spinal cord generation in chick seems to involve two stages:
FGF-dependent establishment of the stem zone, followed by retinoid-dependent
assignment of spinal cord
identity.
Related articles in Development:
- Specification and maintenance of the spinal cord stem zone
- Mariana Delfino-Machín, J. Simon Lunn, Dorette N. Breitkreuz, Jun Akai, and Kate G. Storey
Development 2005 132: 4273-4283.
[Abstract]
[Full Text]