Title | Concentration dependent chromatin states induced by the bicoid morphogen gradient. |
Publication Type | Journal Article |
Year of Publication | 2017 |
Authors | Hannon, CE, Blythe, SA, Wieschaus, EF |
Journal | Elife |
Volume | 6 |
Date Published | 2017 Sep 11 |
ISSN | 2050-084X |
Keywords | Animals, Chromatin, Chromatin Immunoprecipitation, Drosophila, Drosophila Proteins, Gene Expression Regulation, Developmental, Homeodomain Proteins, Protein Binding, Sequence Analysis, DNA, Trans-Activators |
Abstract | <p>In , graded expression of the maternal transcription factor Bicoid (Bcd) provides positional information to activate target genes at different positions along the anterior-posterior axis. We have measured the genome-wide binding profile of Bcd using ChIP-seq in embryos expressing single, uniform levels of Bcd protein, and grouped Bcd-bound targets into four classes based on occupancy at different concentrations. By measuring the biochemical affinity of target enhancers in these classes in vitro and genome-wide chromatin accessibility by ATAC-seq, we found that the occupancy of target sequences by Bcd is not primarily determined by Bcd binding sites, but by chromatin context. Bcd drives an open chromatin state at a subset of its targets. Our data support a model where Bcd influences chromatin structure to gain access to concentration-sensitive targets at high concentrations, while concentration-insensitive targets are found in more accessible chromatin and are bound at low concentrations. This may be a common property of developmental transcription factors that must gain early access to their target enhancers while the chromatin state of the genome is being remodeled during large-scale transitions in the gene regulatory landscape.</p> |
DOI | 10.7554/eLife.28275 |
Alternate Journal | Elife |
PubMed ID | 28891464 |
PubMed Central ID | PMC5624782 |
Grant List | F31 HD082940 / HD / NICHD NIH HHS / United States F32 HD072653 / HD / NICHD NIH HHS / United States T32 GM007388 / GM / NIGMS NIH HHS / United States / HHMI / Howard Hughes Medical Institute / United States |