title: Interactions between Paramecium bursaria (Protozoa, Ciliophora, Hymenostomatida) and their nuclear symbionts: I. Phenomenon of symbiogenic lysis of the bacterium Holospora acuminata.
abstract: In experimental infections the phenomenon of the lysis of symbiotic bacteria (SB) in the host-cell nucleus was discovered for the first time. Light optical investigations were made of 308 possible combinations of experimental infections of 44 clones of originally symbiont-free Paramecium bursaria by 7 strains of SB Holospora acuminata of different origin. In 5% of the cases studied the early stages of infection appeared to be the same as in susceptible strains, but all the SB were lysed during 1-2 days after their penetration of the nucleus. The dynamics and ultrastructural peculiarities of bacterial lysis were thoroughly studied. Possible microevolutionary consequences of direct contacts of heterologous genetic materials in the symbiotic system are discussed.
authors.affiliation: Biological Research Institute of St.-Petersburg State University, Russia.
authors.forename: D V
authors.initials: DV
authors.lastname: Ossipov
authors.forename: I I
authors.initials: II
authors.lastname: Skoblo
authors.forename: O N
authors.initials: ON
authors.lastname: Borchsenius
authors.forename: N A
authors.initials: NA
authors.lastname: Lebedeva