Effect of entry exclusion on mating aggregates and transconjugants.
J Bacteriol
; 129(1): 131-7, 1977 Jan.
Article
en En
| MEDLINE
| ID: mdl-318636
Mating aggregates during conjugation directed by an F-like R factor in Escherichia coli were measured as the number of Lac+-Lac- sectored colonies present in a mating mixture. There is a high degree of correlation between the concentration of transconjugants produced in a mating mixture and the concentration of mating aggregates observed at several different concentrations of donor and recipient cells. The mating aggregates are sex pilus specific as demonstrated by the ability of donor-specific ribonucleic acid phage MS-2 to decrease both mating aggregates and transconjugants in a mating mixture. During entry exclusion by either a derepressed or a repressed F-like R factor, isogenic to the superinfecting R factor except for a resistance determinant, the number of transconjugants was markedly reduced, but the number of mating aggregates was not decreased. Entry exclusion by F-Gal toward the donor HfrH resembled that of the F-like R factor in that there was a reduction in the number of recombinants but no significant decrease in mating aggregates. These results suggest that entry exclusion inhibits conjugation at a stage after the formation of mating aggregates.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Conjugación Genética
/
Escherichia coli
Idioma:
En
Revista:
J Bacteriol
Año:
1977
Tipo del documento:
Article
Pais de publicación:
Estados Unidos