Summary: Using crossing and analysis procedures similar to those applied to Streptomyces coelicolor a3(2), several auxotrophic and streptomycin-resistant markers were located on a circular linkage map of the melanin-producing Streptomyces glaucescens, strain eth22794. The linkage map of S. glaucescens is similar to that of S. coelicolor ≪g≫a≪/g≫3(2), in the sequence of markers and in the presence of two long silent regions.