The Genetic Control Colicinogenic Factors E2 I and V

Publisher Website
Google Scholar
Abstract
The state of colicinogenic factors, E2,1 and V (col E2, col I and col V) in Escherichia coli K 12 was studied. The analysis of the results of conjugation experiments involving different Hfr or F+ and F- strains shows that: (1) The frequency of transfer of these colicinogenic factors differs markedly: col V is transferred with maximum efficiency, col E2 and col 1, on the contrary, only at low frequency. (2) Each colicinogenic factor is transferred from different types of Hfr or F+ strains with similar frequencies. (3) They are not linked with chromosomal markers. (4) The non-colicinogenic character of the donor parent is never transmitted to recombinants. (5) Zygotes that have received col V, transmit it to all daughter cells. All these results lead to the conclusion that colicinogenic factors E2, 1 and V are in an extrachro-mosomal state in F+ and Hfr bacteria. The same conclusion would apply to their state in F- bacteria, since the results with colicinogenic factor V seem to indicate that this factor replicates in this type of bacteria autonomously and at a faster rate than the chromosome.

This publication has 0 references indexed in Scilit: