Physical maps of thiolase isozyme genes and disruption cassettes, and disruption strategies. Horizontal arrows indicate the orientation of transcription. Vertical arrows indicate the popping out of the lacZ-URA3-lacZ cassette. A boxed region of each thiolase gene shows the open reading frame. Restriction sites: Ba, BamHI; Bg, BglII; EI, EcoRI; EV, EcoRV; H, HindIII; K, KpnI; S, SalI.