This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Lloveres, C. P. Articles by Cerdá-Olmedo, E. Search for Related Content PubMed PubMed Citation Articles by Lloveres, C. P. Articles by Cerdá-Olmedo, E.

Nitrosoguanidine Assay of Episomal Integration in Escherichia coli

Departamento de Genética, Facultad de Ciencias, Universidad de Sevilla, Spain

ABSTRACT

Mutations affecting utilization of lactose and resistance to the male-specific phages f1, f2, and Qß tend to occur simultaneously more often than expected by chance in Hfr strains whose origin of transfer is close to the genes for lactose utilization, but not in F⁺ strains. Strains derived from the Hfr, but exhibiting poor ability to transfer early chromosomal genes, may or may not show this comutation phenomenon. These results support the concept that the F factor is integrated into the Hfr chromosome during vegetative growth, but is autonomous in the F⁺ strains and could serve as an assay for episomal localization.