REVERSION OF A LONG-LIVING, UNDIFFERENTIATED MUTANT OF PODOSPORA-ANSERINA BY COPPER

The Podospora anserina nuclear mutant grisea displays an undifferentia ted growth phenotype (diminished production of aerial hyphae), is fema le sterile (lack of perithecia), has a prolonged life-span compared to the wild-type strain, and lacks detectable phenoloxidase (laccase and tyrosinase) activity. Reversion of all of these characteristics to th ose of the wild-type phenotype was accomplished by supplementing the g rowth medium with extra amounts of copper salts. These results indicat e that the primary defect of the grisea strain is in its copper uptake and/or distribution in the cells.