Elements in peaked promoters are associated with embryonic utilization. (a) Maternal and zygotic activity of peaked promoters corresponds to differences in element occurrences. The presence of eight sequence elements was evaluated in peaked core promoters of TSSs using PATSER. Core promoters were segregated into three groups based on their pattern of utilization (maternal, zygotic, both). Those showing no expression during the time course were excluded from this analysis. The normalized means of motif matches in three random intergenic sets are shown. (b) Regulatory modules also segregate by condition for peaked promoters. The numbers of occurrences of motif modules were evaluated in each of the three groups of peaked core promoters (maternal, zygotic, both) by counting the numbers of pairs of matches positioned in the designated order, with respect to the orientation of transcription.