Embryonic enhancers in the dpp disk region regulate a second round of Dpp signaling from the dorsal ectoderm to the mesoderm that represses Zfh-1 expression in a subset of pericardial cells
During germ band elongation, widespread decapentaplegic (dpp) expression in the dorsal ectoderm patterns the underlying mesoderm. These Dpp signals specify cardial and pericardial cell fates in the developing heart. At maximum germ band extension, dpp dorsal ectoderm expression becomes restricted to...
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Published in | Developmental biology Vol. 262; no. 1; pp. 137 - 151 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
United States
Elsevier Inc
01.10.2003
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Subjects | |
Online Access | Get full text |
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Summary: | During germ band elongation, widespread
decapentaplegic (dpp) expression in the dorsal ectoderm patterns the underlying mesoderm. These Dpp signals specify cardial and pericardial cell fates in the developing heart. At maximum germ band extension,
dpp dorsal ectoderm expression becomes restricted to the dorsal-most or leading edge cells (LE). A second round of Dpp signaling then specifies cell shape changes in ectodermal cells leading to dorsal closure. Here we show that a third round of
dpp dorsal ectoderm expression initiates during germ band retraction. This round of
dpp expression is also restricted to LE cells but Dpp signaling specifies the repression of the transcription factor Zfh-1 in a subset of pericardial cells in the underlying mesoderm. Surprisingly, we found that
cis-regulatory sequences that activate the third round of
dpp dorsal ectoderm expression are found in the
dpp disk region. We also show that the activation of this round of
dpp expression is dependent upon prior Dpp signals, the signal transducer
Medea, and possibly release from dTCF-mediated repression. Our results demonstrate that a second round of Dpp signaling from the dorsal ectoderm to the mesoderm is required to pattern the developing heart and that this round of
dpp expression may be activated by combinatorial interactions between Dpp and Wingless. |
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Bibliography: | ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 ObjectType-Article-1 ObjectType-Feature-2 |
ISSN: | 0012-1606 1095-564X |
DOI: | 10.1016/S0012-1606(03)00350-6 |