Genomic comparisons among parental and fusant strains of Candida shehatae and Pichia stipitis.

DNA-DNA binding experiments on selected fusants of Candida shehatae and Pichia stipitis showed that the nucleus of these strains was composed predominantly of Pichia DNA. Electrophoretic karyotyping revealed that the fusants contained four chromosomes, similar to those found in the Pichia parental strain. In addition, the fusants showed only marginal increases in cell DNA content when compared with the parents. Karyogamy was confirmed, however, by the isolation of recombinant phenotypic segregants, induced by meiotic and mitotic segregation. The results suggest that the fusion led to integration of Candida genes, rather than whole chromosomes, with the entire genome of P. stipitis.