Dynamic model for the coordination of two enhancers of broad by EGFR signaling. Author Lily Cheung, David Simakov, Alisa Fuchs, George Pyrowolakis, Stanislav Shvartsman Publication Year 2013 Type Journal Article Abstract Although it is widely appreciated that a typical developmental control gene is regulated by multiple enhancers, coordination of enhancer activities remains poorly understood. We propose a mechanism for such coordination in Drosophila oogenesis, when the expression of the transcription factor Broad (BR) evolves from a uniform to a two-domain pattern that prefigures the formation of two respiratory eggshell appendages. This change reflects sequential activities of two enhancers of the br gene, early and late, both of which are controlled by the epidermal growth factor receptor (EGFR) pathway. The late enhancer controls br in the appendage-producing cells, but the function of the early enhancer remained unclear. We found that the early enhancer is essential for the activity of the late enhancer and induction of eggshell appendages. This requirement can be explained by a mechanism whereby the BR protein produced by the early enhancer protects the late enhancer from EGFR-dependent repression. We illustrate this complex mechanism using a computational model that correctly predicts the wild-type dynamics of BR expression and its response to genetic perturbations. Keywords Animals, Drosophila, Drosophila Proteins, Signal Transduction, Models, Biological, Enhancer Elements, Genetic, Oogenesis, Transcription Factors, Computational Biology, Receptor, Epidermal Growth Factor, Feedback, Physiological Journal Proc Natl Acad Sci U S A Volume 110 Issue 44 Pages 17939-44 Date Published 10/2013 Alternate Journal Proc. Natl. Acad. Sci. U.S.A. Google ScholarBibTeXEndNote X3 XML