Genetic Evidence for a Plasmid Controlling Fertility in an Industrial Strain of Streptomyces rimosus

Abstract

A plasmid (SRP1) determines most of the genetic recombination which occurs between marked derivatives of strain of S. rimosus. SRP1- strains occur with a frequency of about 0.3% among spores of SRP1+ strains. In SRPI+ .times. SRP1- crosses are about 100 times more fertile than SRP1+ .times. SRP1+ crosses (10-3 to 10-4 compared with 10-5 to 10-7. A very low frequency (about 10-8) of true recombinants occurs in the absence of SRP1.