Hybridization of polyketide synthase genes from heterologous Streptomyces sp. led to the identification of four unlinked regions of DNA from Streptomyces peucetius that contain genes that encode the production of the same or closely related metabolites, some of which are intermediates of the daunorubicin pathway. DNA fragments from each region that hybridized with the heterologous polyketide synthase genes were hybridized with each other, but very little sequence similarity was observed even though at least two of the regions have similar (if not identical) functions in metabolite production. Some regions, however, do have sequence similarity with other anthracycline-producing Streptomyces sp.