HIGH-FREQUENCY TRANSFORMATION OF THE FISSION YEAST SCHIZOSACCHAROMYCES-POMBE

The fission yeast, S. pombe, has been used extensively for genetic studies but until now has not been utilized as a host organism for DNA cloning. A method is described for high-frequency transformation of a leu 1- strain of this yeast with hybrid plasmids containing the Saccharomyces cerevisiae LEU 2+ gene, a bacterial plasmid and either the S. cerevisiae 2 .mu.m plasmid or autonomously replicating sequences (ars)1 derived from Schizosaccharomyces pombe DNA. Some of the plasmids contain unique restriction sites which make them suitable for the isolation of S. pombe genes; they can also be used for the exchange of DNA between S. pombe and Saccharomyces cerevisiae.