A high-resolution map of enhancer three-dimensional contacts during Drosophila embryogenesis shows that although local regulatory interactions are frequent, long-range interactions are also very common; unexpectedly, most interactions appear unchanged between tissues and across development and are formed prior to gene expression, indicating that transcription initiates from preformed enhancer–promoter loops, which are associated with paused polymerase.
- Yad Ghavi-Helm
- Felix A. Klein
- Eileen E. M. Furlong