Growth of the wild-type and das1Δ strains on various carbon and nitrogen sources. MA, methylamine. Symbols: •, wild-type strain; ○, das1Δ strain; □, aod1Δ · das1Δ strain; ▵, das1Δ strain expressing DAS1 under control of the AOD1 promoter. O.D. 610, optical density at 610 nm.