Distinct requirements for extra-embryonic and embryonic bone morphogenetic protein 4 in the formation of the node and primitive streak and coordination of left-right asymmetry in the mouse.
Journal Article (Journal Article)
In the mouse and chick embryo, the node plays a central role in generating left-right (LR) positional information. Using several different strategies, we provide evidence in the mouse that bone morphogenetic protein 4 (Bmp4) is required independently in two different sites for node morphogenesis and for LR patterning. Bmp4 expression in the trophoblast-derived extra-embryonic ectoderm is essential for the normal formation of the node and primitive streak. However, tetraploid chimera analysis demonstrates that Bmp4 made in epiblast-derived tissues is required for robust LR patterning, even when normal node morphology is restored. In the absence of embryonic Bmp4, the expression of left-side determinants such as Nodal and Lefty2 is absent in the left lateral plate mesoderm (LPM). Noggin-mediated inhibition of Bmp activity in cultured wild-type embryos results in suppression of Nodal expression in the LPM. Thus, unlike previous models proposed in the chick embryo in which Bmp4 suppresses left-sided gene expression, our results suggest that Bmp acts as a positive facilitator of the left-sided molecular cascade and is required for Nodal induction and maintenance in the left LPM.
Full Text
Duke Authors
Cited Authors
- Fujiwara, T; Dehart, DB; Sulik, KK; Hogan, BLM
Published Date
- October 2002
Published In
Volume / Issue
- 129 / 20
Start / End Page
- 4685 - 4696
PubMed ID
- 12361961
International Standard Serial Number (ISSN)
- 0950-1991
Digital Object Identifier (DOI)
- 10.1242/dev.129.20.4685
Language
- eng
Conference Location
- England