Expression of doxorubicin-daunorubicin resistance genes in different anthracycline-producing mutants of Streptomyces peucetius

The expression of doxorubicin gene (ric1) and daunorubicin (ric2) in the different mutant strains of Streptomyces peucetius was investigated using Northern blot analysis of RNA transcripts from these genes. Results reveal that the concentration of RNA transcript is higher in strain 7600 than in strain 7900. Two other mutants, strain 8600 and strain 9700 did not express the transcript although both strains were derived from strain 7900. ric1 and ric2 exhibit different restriction patterns and are not homologous, however, both genes confer resistance to the strains producing them.