Differential stability of filamentous phage genomes in Xanthomonas campestris pv citri
Dai, H.; Liao, H.J.; Chiang, K.S.
Microbios 56: 228-229
1988
ISSN/ISBN: 0026-2633 PMID: 3241573 Document Number: 312059
Stability of the phage genome in carrier cells (filamentous phage-infected X. campestris pv. citri) varied considerably even for closely related phage types. The spontaneous curing frequency for cells infected by Cf16-12, Cf16, Cf-v1 and Cf was 1, 5, 96 and 100%, respectively. The size of the phage replicative-form (RF) pool which built up rapidly at the onset of Cf16 infection was critical to the maintenance of the carrier state and the eventual integration of the prophage. A correlation in stability between phage carrier state in infected cells and lysogeny was found for these phages. The past history of a phage infection altered the response of the cured host to reinfection. In those cured cells which remained susceptible, the stability of the reinfecting phage genome was not altered appreciably, while a distinctive new plaque morphology appeared in >50% of these cells. These alterations were not dependent on the prophage integration prior to curing, and no phage DNA was detected in cured cells by blot hybridization. Notwithstanding these changes, the sites of phage integration in cured cells remained the same as the original infection on both the phage RF and the host chromosome.