Open AccessHoxa2 downregulates Six2 in the neural crest-derived mesenchyme
Author(s) -
Eva Kutějová,
Bettina Engist,
Bernard Malissen,
Benoı̂t Kanzler,
Nicoletta Bobola
Publication year - 2005
Publication title -
development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.754
H-Index - 325
eISSN - 1477-9129
pISSN - 0950-1991
DOI - 10.1242/dev.01536
Subject(s) - biology , transcription factor , hox gene , phenotype , mutant , microbiology and biotechnology , mesenchyme , neural crest , transgene , signal transducing adaptor protein , genetics , gene , embryo , signal transduction
The Hoxa2 transcription factor acts during development of the second branchial arch. As for most of the developmental processes controlled by Hox proteins, the mechanism by which Hoxa2 regulates the morphology of second branchial arch derivatives is unclear. We show that Six2, another transcription factor, is genetically downstream of Hoxa2. High levels of Six2 are observed in the Hoxa2 loss-of-function mutant. By using a transgenic approach to overexpress Six2 in the embryonic area controlled by Hoxa2, we observed a phenotype that is reminiscent of the Hoxa2 mutant phenotype. Furthermore, we demonstrate that Hoxa2 regulation of Six2 is confined to a 0.9 kb fragment of the Six2 promoter and that Hoxa2 binds to this promoter region. These results strongly suggest that Six2 is a direct target of Hoxa2.