DNA replication in vivo of linear DNA killer plasmids pGKL1 and pGKL2 inSaccharomyces cerevisiae

Electron microscopic observation demonstrated that linear DNA plasmids, pGKL1 and pGKL2, were replicated by a strand displacement mechanism similar to adenovirus and Bacillus subtilis ∅ 29 phage. Moreover, their DNA replication was prevented by α-factor, a mating hormone which prevents the replication of chromosomal DNA and 2 µm plasmid in Saccharomyces cerevisiae mating type a cells. This result suggests that the replication of pGKL plasmids is controlled by the same genes that control the initiation or maintenance of chromosomal DNA and 2 µm plasmid replications.