Southern blot of genomic DNA confirms spontaneous LOH and CRE-mediated loss of LHTL cassette at the PYR6-5 locus. C and CTr denote cells transfected with pLEW100Cre stably or transiently, respectively. In the PYR6-5 locus, clones are wild type (+/+), heterozygous (+/H) or homozygous (H/H) for LHTL, prior to CRE induction. In lanes 6–9, cells were induced with doxycycline and selected in GCV. Blot was probed for HYG, which detects LHTL and a smaller band from a fragment of HYG, which is present in all SM-derived cells. The blot was reprobed for PYR6.