title: Protoplast fusion permits high-frequency transfer of a Streptomyces determinant which mediates actinomycin synthesis.
abstract: Prototrophic recombinants and heterocaryotic colonies developed at high frequency when protoplasts of nutritionally complementary actinomycin-producing and nonproducing strains of Streptomyces antibioticus were fused in the presence of polyethylene glycol and plated on minimal regeneration medium. Of the spores obtained from aerial hyphae of a single heterocaryotic colony, 99% carried the act+ character regardless of whether the nutritional markers of the spore were derived from the act+ or the act parent. Similarly, a high-frequency transfer (68% in S. antibioticus, 48% in Streptomyces parvulus) of act+ determinant(s) to act was achieved by protoplast fusion. Protoplasts of a doubly auxotrophic act strain of S. parvulus were efficiently transformed in the presence of polyethylene glycol with respect to the auxotrophic markers by DNA of an act+ auxotrophic strain with complementary nutritional requirements. The transformation frequency of the nutritional (chromosomal) markers was 17%. In contrast, the transformation frequency for actinomycin synthesis was less than 1%.
mesh_terms: D002876:Chromosomes, Bacterial; D003609:Dactinomycin / Q000096:biosynthesis*; D005798:Genes, Bacterial; D010957:Plasmids; D011092:Polyethylene Glycols; D011523:Protoplasts / Q000502:physiology; D011995:Recombination, Genetic; D013302:Streptomyces / Q000235:genetics* / Q000378:metabolism; D013303:Streptomyces antibioticus / Q000235:genetics*; D014169:Transformation, Bacterial
chemical_list: D003609:Dactinomycin; D011092:Polyethylene Glycols