Cloning of whiG, a gene critical for sporulation of Streptomyces coelicolor A3(2)

In whiG mutants of Streptomyces coelicolor A3(2), aerial hyphae do not show any sign of sporulation. A library of S. coelicolor DNA was prepared in a phi C31 temperate phage vector (KC516), and one recombinant phage (KC750) that could restore the wild-type phenotype to a collection of whiG mutants when integrated into their genomes was found. Subcloning experiments with low- and high-copy-number Streptomyces plasmid vectors allowed partial localization of whiG in the cloned DNA and revealed that hypersporulation was associated with the presence of extra copies of whiG.