Karyotype studies on different strains of Candida molischiana by pulsed-field gel electrophoresis

We used pulsed-field gel electrophoresis to compare the electrophoretic karyotype of a Candida molischiana mutant, de-repressed for beta-glucosidase production, with a wild-type strain and a reference strain. The chromosomal organization in this mutant yeast was found to be quite different. Hybridization patterns and the relative fluorescence of all bands indicated eight chromosomes in the mutant strain and seven in the other two. All three strains seemed to be haploid, with an estimated genome size of 12 Mb; the beta-glucosidase gene was on the same chromosome in all of them and the SfiI restriction patterns of this chromosome indicated that it is not affected by the mutation.