Analysis of an inactivated Lg-FLO1 gene present in bottom-fermenting yeast

During the course of investigating a flocculation-related gene of a bottom-fermenting yeast, we identified a new Lg-FL01 homologue which contains the N-terminal domain of the Lg-FL01 gene. The results of the partial DNA sequence analysis of the amplified product obtained by inverse-PCR suggested that the homologue contains a sequence present in the YIL169c (chr. IX of Saccharomyces cerevisiae). Southern blot analyses using the VTH1, HXT12, SDL1 and UBP7 genes as probes for chr. IX strongly indicated that an approximately 20-kb region from the YIL169c ORF to the left telomere in chr. IX translocated to the Lg-FL01 ORF region in chr. VIII of bottom-fermenting yeast. This translocation might convert a flocculent cell to a non-flocculent one.