Trisporic acid synthesis in Blakeslea trispora

Cultures of the (-) strain of Blakeslea trispora synthesize trisporic acid C, a sex hormone, from precursors made by cultures of the (+) strain. The precursors are nonacidic compounds isolated from the culture medium of the (+) strain by chloroform extraction. Actidione does not inhibit trisporic acid synthesis from isolated precursors, suggesting that the enzymes involved in the synthesis in cultures of the (-) strain are constitutive.