Molecular genetic properties of the yeast Torulaspora pretoriensis: characterization of chromosomal DNA and genetic transformation by Saccharomyces cerevisiae-based plasmids.

Chromosomal DNA banding patterns were obtained for three strains of Torulaspora pretoriensis by contour-clamped homogeneous-electric-field gel electrophoresis. Chromosomes were resolved into six or seven bands in the range of 800 to 2000 kb, and a polymorphism of these lengths was observed. By Southern-blot analysis, the three strains were shown to lack the DNA sequences homologous to the URA3, LEU2, TRP1, and HO genes of Saccharomyces cerevisiae. A uracil auxotrophic mutant derived from T. pretoriensis was transformed with three plasmids (YEp24, YRpHI, and YCp50) carrying the URA3 gene of S. cerevisiae by the lithium acetate method.