|Application:||Gene expression microarray analysis|
|Number of samples:||44|
|Release date:||Sep 1 2006|
|Last update date:||Feb 18 2018|
|Dataset link||Hex acts with β-catenin to regulate anterior-posterior|
Identification of Hex target genes In Xenopus, the establishment of the anterior-posterior axis involves two key signalling pathways, the canonical Wnt and the Nodal-related TGF-β and a number of transcription factors that feedback upon these pathways. The homeodomain protein Hex, an early marker of anterior positional information, is a transcriptional repressor that suppresses the induction and propagation of the Spemman organiser while specifying anterior identity. Using microarray expression profiling we identified mouse Tle-4 as a Hex target in Embryonic Stem (ES) cells and showed that Tle-4 expression is directly regulated by Hex in Xenopus embryos. We also identified Nodal as a Hex target in ES cells. Taken together these results support a model in which Hex acts early in development to reinforce a Wnt-mediated, Nieuwkoop-like signal to induce anterior endoderm and later in this tissue to block further propagation of Nodal-related signals. The ability of Hex to regulate the same targets in both frog and mouse suggests that this model is conserved.
Joshua M. Brickman