Fig. 4

A systems view on morphological development of the wild type S. rimosus ATCC 10970 (R7), its mutagenized oxytetracycline-producing derivative HP126 (HP), and the chassis strain HP126 Δv3 (DV3), created by deletion of the oxytetracycline cluster. The data show differences in the expression of genes associated with morphology, sporulation, and cell wall biosynthesis (A) (n=3). The differences in gene expression are represented as M-values between strain HP versus R7 (y-axis) and strain DV3 versus wild-type (x-axis) so that correlations between all strains can be inferred from the plot. The data represent the major phase of oxytetracycline production after 24 h. The functional annotation of genes, designated by SRIMR7 numbers on basis of the sequenced genomes, is provided in Additional file 2. In addition, the data show changes in the cellular morphology, visualized by light microscopy at different time points of cultivation (8h, 24 h, 48 h, 72h), for the wildtype (B) and the hyper-producer HP126 (C)