F' strains of E. coli have been isolated which are merodiploid for various chromosomal segments between 66 and 78 minutes. Strains diploid for the chromosomal DNA between the genes bgl and mtl grow slowly, have a reduced DNA/mass and an increased cell size. These properties could result if the chrom
The frequency of P1 transduction of the genes of Escherichia coli as a function of chromosomal position: Preferential transduction of the origin of replication
β Scribed by Masters, Millicent
- Publisher
- Springer
- Year
- 1977
- Tongue
- English
- Weight
- 565 KB
- Volume
- 155
- Category
- Article
- ISSN
- 0026-8925
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β¦ Synopsis
The frequencies with which the generalized transducing phage P1 transduced 26 selected markers on the E. coli. chromosome were measured. The frequencies were found to vary relative to argH+ = 1 from a maximum of 6.8 near the origin of replication to a minimum of 0.23 for a marker not far from the terminus. The low frequencies obtained for some markers were shown not to result from poor expression under the selective conditions employed. When plotted as a function of marker position on the chromosome the frequencies were found to exhibit a series of peaks and troughs which correspond to those in gene density noted by Bachmann et al. (1976). The possible relationship of these results to the structure of the E. coli chromosome and to the mechanism of generalized transduction are discussed.
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