Abstract
The prokaryote Escherichia coli successfully conjugated with the eukaryote Saccharomyces kluyveri, which is relatively distant from the species S. cerevisiae. To achieve this transkingdom conjugation, we constructed three types of conjugative plasmids, namely integrative, replicative, and centromere vectors, for S. cerevisiae. By transfer of any of the three plasmids from E. coli, an S. kluyveri Ura- mutant was converted to the Ura+ phenotype. This phenotype was easily lost under nonselective conditions. Southern analysis of the transconjugants clearly indicated the presence of the plasmids in many different structures and sizes.