First published online October 12, 2007
Development 134, 2105e (2007)
© The Company of Biologists Limited
Nodal signals take an internal route
The left-right asymmetry of internal organs is established during mammalian
development by a leftward fluid flow in the embryonic node cavity, expression
of the secreted protein Nodal at the node, and subsequent asymmetric Nodal
expression in the left lateral plate mesoderm (LPM). But, how is the Nodal
signal transferred to the LPM? On
p. 3893, Oki and
co-workers controversially propose that Nodal travels directly to the LPM from
the node by interacting with sulfated glycosaminoglycans (GAGs) in the
intervening basement membrane-like structure. The researchers show that
externally supplied Nodal does not signal to the LPM in cultured mouse
embryos, which suggests that an internal route exists for Nodal signal
transfer to the LPM. They discount that Nodal signals might be indirectly
relayed by showing that the Nodal co-receptor Cryptic is not needed in the
node for asymmetric Nodal expression in the LPM. Finally, they show that Nodal
interacts with sulfated GAGs and that inhibition of their biosynthesis
prevents Nodal expression in the LPM.
Related articles in Development:
- Sulfated glycosaminoglycans are necessary for Nodal signal transmission from the node to the left lateral plate in the mouse embryo
- Shinya Oki, Ryuju Hashimoto, Yuko Okui, Michael M. Shen, Eisuke Mekada, Hiroki Otani, Yukio Saijoh, and Hiroshi Hamada
Development 2007 134: 3893-3904.
[Abstract]
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