The Phenoloxidases * of the Ascomycete Podospora

N communication I11 (ESSEH 1966) of this series of papers, eleven loci belongI ing to six different linkage groups are described. These loci not only influence morphological characteristics, but also the formation of melanin pigments in Podospora. A preliminary biochemical analysis of these mutants has shown that at least two of these loci, the unlinked genes zonata and flexuosa, control the synthesis of the phenoloxidases which are responsible for the pigment formation. Mutations in these genes result in a different spectrum of the laccases. Both mutants form only small amounts of high molecular weight laccases, which account for most of the phenoloxidases in the wild strain (ESSER, DICK and GIELEN 1964). In addition the mutants produce laccases hitherto undemonstrable in the wildtype strain (ESSER 1966). On the basis of these first results it was not possible to explain the defects in these strains. The prerequisites for such a model, purification and characterization of the laccases of both mutants, are reported in the present paper. The data presented support the hypothesis that both loci control the aggregation of enzyme monomers to the high molecular weight laccase.