Role ofdnaB43 in F′-plasmid incompatibility

Abstract

In order to perform complementation tests with mutations of DNA replication of F′-plasmids incompatibility must be overcome. We report our inability to duplicate the results presented by Palchoudhury and Iyer (1971) and Bezanson and Iyer (1975) who have claimed to demonstrate the autonomous replication of two incompatible F′-plasmids in a strain carrying the temperature sensitivednaB43 allele. In addition, we describe experiments designed to measure complementation using transient heterozygote and compatible plasmids. Assessment of our data and those of others in the light of a recent report by Uhlin and Nordström (1975) suggests that new approaches will have to be developed for the successful employment of complementation analysis in F-plasmid genetics.