GENOMIC COMPARISONS AMONG PARENTAL AND FUSANT STRAINS OF CANDIDA-SHEHATAE AND PICHIA-STIPITIS

DNA-DNA binding experiments on selected fusants of Candida shehatae an d Pichia stipitis showed that the nucleus of these strains was compose d predominantly of Pichia DNA. Electrophoretic karyotyping revealed th at the fusants contained four chromosomes, similar to those found in t he Pichia parental strain. In addition, the fusants showed only margin al increases in cell DNA content when compared with the parents. Karyo gamy was confirmed, however, by the isolation of recombinant phenotypi c segregants, induced by meiotic and mitotic segregation. The results suggest that the fusion led to integration of Candida genes, rather th an whole chromosomes, with the entire genome of P. stipitis.