Expression profiles of antisense RNAs within secondary metabolite clusters. (A) Expression profile of the asRNA expressed opposite hopC in S. coelicolor (left) and S. avermitilis (right). (B) Expression of the two asRNAs expressed opposite cpkE and cpkH within the coelimycin P1 biosynthetic cluster of S. coelicolor. The relative position of these two genes within the cluster is shown above the coverage graphs. (C) Expression levels for scbA and scbR within the coelimycin P1 biosynthetic cluster in S. coelicolor. Antisense RNAs resulted from the divergent transcription of these two genes  and an independent antisense RNA was expressed within the coding region of scbA. (D) Expression profile of the asRNA expressed opposite redG within the prodiginine biosynthetic cluster of S. coelicolor. For each of (A-D), relative sequence reads at each nucleotide position were shown in red (positive strand on the top), and blue (negative strand on the bottom). The y-axis of each gene set was scaled independently, as expression levels of different gene clusters varied.