GENE TRANSFER BY F′ STRAINS OF ESCHERICHIA COLI K-12 II

Gene Transfer by F' Strains of Escherichia Coli K-12. I. Delay in Initiation of Chromosome Transfer.

Pittard, James (Yale University, New Haven, Conn.), John S. Loutit, and Edward A. Adelberg. Gene transfer by F' strains of Escherichia coli K-12. I. Delay in initiation of chromosome transfer. J. Bacteriol. 85:1394-1401. 1963.-Two different F' strains were found to transfer both F-merogenote and chromosomal markers to recipient strains. When zygotes having received different chromosomal markers...

Hfr Strains of Escherichia coli K-12

Since the first reports by Cavalli-Sforza (9) and Hayes (24) of strains of Escherichia coli K-12 which are conjugational donors of chromosomal markers at high frequency (Hfr strains), many other Hfr strains have been isolated and our understanding of the mechanisms involved in Hfr formation has increased considerably. All Hfr strains arise from the integration of a conjugative plasmid into the ...

Chromosome transfer from F-lac+ strains of Escherichia coli K-12 mutant at recA, recB, or recC.

The frequency of chromosome transfer from various recombination-deficient F-lac(+) donor strains was estimated by standardizing the yield of conjugants receiving a male chromosomal marker against the level of episome transfer in the mating mixture. The efficiency of chromosome transfer from newly formed F-lac(+) cells carrying recB21 or recC22 was more than 50% of the wild-type value, although ...

F+ strains of Escherichia coli K-12 defective in Hfr formation.

Nonrandom F-plasmid replication in Escherichia coli K-12.

Both the autonomous and chromosomally integrated F plasmids were found to replicate in a nonrandom fashion after a density transfer from heavy medium ([13C]glucose, 15NH4) to light medium ([12C]glucose, 14NH4). The data are consistent with the hypothesis that both the chromosome and the F plasmid are replicated in a cell cycle-specific manner. Thus, these data support the proposal (J. D. Keasli...