CaLC4330: To generate a SWI6 homozygous deletion mutant, the NAT flipper cassette (pLC49)60 was PCR amplified using primers oLC3641 in combination with oLC3642 and transformed into CaLC239 (SN95). NAT-resistant transformants were PCR tested with oLC275 in combination with oLC3645 and oLC274 in combination with oLC3654. The SAP2 promoter was induced to drive expression of FLP recombinase to excise the NAT flipper cassette. Once again, the NAT flipper cassette (pLC49)60 was PCR amplified using primers oLC3641 in combination with oLC3642 and transformed into SWI6/swi6::FRT. NAT-resistant transformants were PCR tested as described above. The absence of a wild-type allele and the presence of the deleted allele was verified with oLC3645 in combination with oLC3431. The SAP2 promoter was induced to drive expression of FLP recombinase to excise the NAT flipper cassette.