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Strongylocentrotus purpuratus transcription factor GATA-E binds to and represses transcription at an Otx-Goosecoid cis-regulatory element within the aboral ectoderm-specific spec2a enhancer
During Strongylocentrotus purpuratus embryogenesis, aboral ectoderm-specific expression of spec2a relies on an upstream enhancer that confers its spatial specificity largely through repression. The purpose of this study was to determine how spec2a expression is repressed in endoderm and oral ectoder...
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Published in: | Developmental biology 2005-04, Vol.280 (2), p.436-447 |
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Main Authors: | , , , , , , |
Format: | Article |
Language: | English |
Subjects: | |
Citations: | Items that this one cites Items that cite this one |
Online Access: | Get full text |
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Summary: | During
Strongylocentrotus purpuratus embryogenesis, aboral ectoderm-specific expression of
spec2a relies on an upstream enhancer that confers its spatial specificity largely through repression. The purpose of this study was to determine how
spec2a expression is repressed in endoderm and oral ectoderm territories. A 78-base pair DNA sequence within the enhancer contains five tightly spaced
cis-regulatory elements including proximal (TAATCT) and distal (TAATCC) elements that bind to both SpOtx, a broadly distributed transcriptional activator, and SpGoosecoid (SpGsc), an oral ectoderm-restricted transcriptional repressor. We show here that these two seemingly redundant Otx/Gsc elements have distinct functions. The proximal element bound to SpGATA-E, an endomesoderm-specific transcription factor. Treatment with SpGATA-E and SpGsc morpholino antisense oligonucleotides (MASOs) resulted in enhanced transcriptional activity from the proximal element, suggesting that both factors functioned as repressors at this site. SpGATA-E MASO-treated embryos failed to express ectoderm markers, indicating a role for SpGATA-E in ectoderm differentiation. The
spec2a proximal element was distinct from the corresponding element in the related
spec1 enhancer, and swaps between
spec1 and
spec2a cis-regulatory elements indicated, that for optimal repression, the proximal element had to interact with a nearby CCAAT-binding factor element. Our results show that the recently evolved proximal element contributes to the repression of
spec2a in endomesoderm and oral ectoderm territories. |
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ISSN: | 0012-1606 1095-564X |
DOI: | 10.1016/j.ydbio.2005.01.021 |