CHROMOSOMAL-POLYMORPHISM OF THE YEAST YARROWIA-LIPOLYTICA AND RELATEDSPECIES - ELECTROPHORETIC KARYOTYPING AND HYBRIDIZATION WITH CLONED GENES

Significant differences in electrophoretic karyotyping patterns were f ound among 27 strains of Y. lipolytica. Twenty-one of these strains we re classified into four groups of similar karyotypes while six strains showed unique karyotypes. Chromosomal DNAs of different strains were hybridized with cloned genes of Y lipolytica (URA3, LEU2, ARS18 and AR S68), which revealed four different bands in most strains. We conclude that the haploid chromosome number of Y lipolytica is at least four, and possibly five or six. Electrophoretic karyotyping and hybridizatio n with cloned genes of Y lipolytica provided evidence of a large diver gence between Y lipolytica and related species of Saccharomycopsis, En domycopsella and Endomyces.