The initiation of transcription at appropriate sites in the genome is critical for development and yet few rules governing selection are known and no core promoter element has so far been assigned a specific role in development. We used cap analysis of gene expression (CAGE) to map transcription start sites (TSSs) at single-bp resolution genome-wide at six key stages of development in O. dioica and uncovered a suite of promoter codes governing transcription initiation at key developmental transitions. We found promoter features that are conserved with vertebrates as well as features that are remarkably divergent, particularly the modes of transcription initiation used at maternal and spermatogenic promoters.
*+G.B. Danks, *P. Navratilova, B. Lenhard, and +E.M. Thompson. Distinct core promoter codes drive transcription initiation at developmental transitions. Submitted.