|
|
|
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Development, Vol 127, Issue 14 3173-3183, Copyright © 2000 by Company of Biologists
JOURNAL ARTICLES |
K Certel, A Hudson, SB Carroll and WA Johnson
University of Iowa, Genetics Program, College of Medicine, Department of Physiology and Biophysics, Iowa City, Iowa 52242, USA.
The Drosophila Vestigial protein has been shown to play an essential role in the regulation of cell proliferation and differentiation within the developing wing imaginal disc. Cell-specific expression of vg is controlled by two separate transcriptional enhancers. The boundary enhancer controls expression in cells near the dorsoventral (DV) boundary and is regulated by the Notch signal transduction pathway, while the quadrant enhancer responds to the Decapentaplegic and Wingless morphogen gradients emanating from cells near the anteroposterior (AP) and DV boundaries, respectively. MAD-dependent activation of the vestigial quadrant enhancer results in broad expression throughout the wing pouch but is excluded from cells near the DV boundary. This has previously been thought to be due to direct repression by a signal from the DV boundary; however, we show that this exclusion of quadrant enhancer-dependent expression from the DV boundary is due to the absence of an additional essential activator in those cells. The Drosophila POU domain transcriptional regulator, Drifter, is expressed in all cells within the wing pouch expressing a vgQ-lacZ transgene and is also excluded from the DV boundary. Viable drifter hypomorphic mutations cause defects in cell proliferation and wing vein patterning correlated with decreased quadrant enhancer-dependent expression. Drifter misexpression at the DV boundary using the GAL4/UAS system causes ectopic outgrowths at the distal wing tip due to induction of aberrant Vestigial expression, while a dominant-negative Drifter isoform represses expression of vgQ-lacZ and causes severe notching of the adult wing. In addition, we have identified an essential evolutionarily conserved sequence element bound by the Drifter protein with high affinity and located adjacent to the MAD binding site within the quadrant enhancer. Our results demonstrate that Drifter functions along with MAD as a direct activator of Vestigial expression in the wing pouch.
This article has been cited by other articles:
|
|
 |
|
  T. Oren, I. Torregroza, and T. Evans An Oct-1 binding site mediates activation of the gata2 promoter by BMP signaling Nucleic Acids Res., August 1, 2005; 33(13): 4357 - 4367. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Hori, M. Fostier, M. Ito, T. J. Fuwa, M. J. Go, H. Okano, M. Baron, and K. Matsuno Drosophila Deltex mediates Suppressor of Hairless-independent and late-endosomal activation of Notch signaling Development, November 15, 2004; 131(22): 5527 - 5537. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. J. Certel and S. Thor Specification of Drosophila motoneuron identity by the combinatorial action of POU and LIM-HD factors Development, November 1, 2004; 131(21): 5429 - 5439. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Martin-Castellanos and B. A. Edgar A characterization of the effects of Dpp signaling on cell growth and proliferation in the Drosophila wing Development, March 4, 2003; 129(4): 1003 - 1013. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Barolo and J. W. Posakony Three habits of highly effective signaling pathways: principles of transcriptional control by developmental cell signaling Genes & Dev., May 15, 2002; 16(10): 1167 - 1181. [Full Text] [PDF]
|
|
|
|
|
|
T. Marty, M. A. Vigano, C. Ribeiro, U. Nussbaumer, N. C. Grieder, and M. Affolter A HOX complex, a repressor element and a 50 bp sequence confer regional specificity to a DPP-responsive enhancer Development, July 15, 2001; 128(14): 2833 - 2845. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. A. Guss, C. E. Nelson, A. Hudson, M. E. Kraus, and S. B. Carroll Control of a Genetic Regulatory Network by a Selector Gene Science, May 11, 2001; 292(5519): 1164 - 1167. [Abstract] [Full Text]
|
|
|
|
 |
|
 H. Kirkpatrick, K. Johnson, and A. Laughon Repression of Dpp Targets by Binding of Brinker to Mad Sites J. Biol. Chem., May 18, 2001; 276(21): 18216 - 18222. [Abstract] [Full Text] [PDF]
|
|
