First published online May 1, 2006
Development 133, 1005e (2006)
© The Company of Biologists Limited
Endoderm gets networked
The key factors involved in vertebrate embryonic endoderm formation include
the Nodal ligands, Mix-like paired homeodomain transcription factors, Gata
transcription factors and Sox17 proteins. Although the relationships between
these proteins are commonly described using a linear model - in which Nodal
proteins regulate Mixer and Gata, which then regulate Sox17 to turn on
endoderm target genes - Zorn and colleagues (p.
1955) have now used
microarrays and loss-of-function experiments in Xenopus to show that
the story is more complicated. They identified 300 transcripts enriched in the
gastrula endoderm, which included most of the known endoderm regulators and
several hundred uncharacterised sequences. Surprisingly, the linear model of
endoderm formation only predicted 10% of the endoderm transcriptome. The
authors also identified several novel epistatic relationships, including
autoregulatory loops between Sox, Gata, Bix and Xnr4. They also found that,
contrary to common understanding, much of Mixer activity is independent of
Sox17. This first global analysis of vertebrate endoderm formation will be a
vital reference point for future experiments into this complex molecular
network.
Related articles in Development:
- Global analysis of the transcriptional network controlling Xenopus endoderm formation
- Débora Sinner, Pavel Kirilenko, Scott Rankin, Eric Wei, Laura Howard, Matthew Kofron, Janet Heasman, Hugh R. Woodland, and Aaron M. Zorn
Development 2006 133: 1955-1966.
[Abstract]
[Full Text]
