title: Plasmid copy number and stability determination in Clostridium perfringens transformants.
abstract: The copy number of the streptococcal plasmid pAM beta 1 (26.5 kb), and its deletion derivatives, pVA1 (11 kb) and pVA677 (7.6 kb) contained in Clostridium perfringens 3624A transformants was determined by incorporation of [methyl-3H]thymidine (4 muCi/ml) into chromosomal and plasmid DNA and sizing of the C. perfringens genome using transverse alternating field electrophoresis. Plasmids pAM beta 1, pVA1, and pVA677 were found to be present at 1.0, 97, and 216 copies/cell, respectively. 10.2, 54, and 96% of the initial pAM beta 1-, pVA1- and pVA677-containing transformants, respectively, remained resistant to erythromycin over 220 generations of growth. The results indicate a size-dependent relationship between plasmid stability and plasmid copy number in C. perfringens.
authors.affiliation: Department of Food Science, University of Illinois, Urbana 61801.
authors.forename: S P
authors.initials: SP
authors.lastname: Allen
authors.forename: H P
authors.initials: HP
authors.lastname: Blaschek
mesh_terms: D003016:Clostridium perfringens / Q000187:drug effects / Q000235:genetics*; D004269:DNA, Bacterial / Q000096:biosynthesis*; D004351:Drug Resistance; D004917:Erythromycin / Q000494:pharmacology; D005784:Gene Amplification; D010957:Plasmids; D014169:Transformation, Bacterial
chemical_list: D004269:DNA, Bacterial; D004917:Erythromycin