Observations on the Adsorption of Caulobacter Bacteriophages containing Ribonucleic Acid

Schmidt, Jean M.

doi:10.1099/00221287-45-2-347

Cited by 74 publications

(46 citation statements)

References 8 publications

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“…This interpretation is supported by a previous observation that the stalk formation is a slow process and requires several bacterial generations to attain its maximal length [4,11]. The unique features of Caulobacter morphogenesis are an obligatory transition of the swarmer cell to the stalked cell before cell division and the expression of the polar structures (a stalk, a single flagellum and pili) at the specific time of the cell cycle [5,6,8,12]. For the study of this cell differentiation, several techniques have been employed to obtain synchronous Caulobacter culture.…”

Section: Methodssupporting

confidence: 64%

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Synchronous Cell Differentiation in Caulobacter crescentus

Iba

Fukuda

Okada

1975

Japanese Journal of Microbiology

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The growth of a stalked bacterium, Caulobacter crescentus, has been synchronized easily and reproducibly by a new method. When this bacterium is grown to a late log phase in nutrient broth at 30 C with aeration, swarmer cells are accumulated in the culture to 80% of the whole cell population. When this culture is inoculated into fresh pre-warmed broth at twentyfold dilution, it immediately initiates synchronous cell growth. Simultaneously, synchronous cell differentiation is monitored by the susceptibility of the cells to RNA phage infection. The swarmer cells accumulated in the late log phase of growth possess nearly the same susceptibility to RNA phage infection as those in the early log phase of growth while RNA phage-adsorbing capacity is lower in such swarmer cells. It is suggested that the swarmer cells accumulated in the late log phase of growth have lost some pili.

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Section: Methodssupporting

confidence: 64%

“…The stalked cell possesses a polar stalk. The motile swarmer cell possesses a single flagellum and pili that are localized at proximal polar sites [6], and undergoes obligatory transition to the stalked cell before cell division.…”

mentioning

confidence: 99%

Synchronous Cell Differentiation in Caulobacter crescentus

Iba

Fukuda

Okada

1975

Japanese Journal of Microbiology

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“…Most resistant strains no longer bind the bacteriophage and also lose the other polar organelles, except for the stalk. Such r strains were then examined for motility and sensitivity to a pilus-specific bacteriophage (r (21). The mutants were also examined by negative-stain electron microscopy for the presence of pili and flagella.…”

Section: Bacterial Strains and Growth Conditionsmentioning

confidence: 99%

Localizing the subunit pool for the temporally regulated polar pili of Caulobacter crescentus.

Smit

1987

The Journal of Cell Biology

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A b s t r a c t .The pili of the stalked bacterium Caulobacter crescentus are assembled at a specific time in the life cycle at one pole of the cell and are composed of the monomer protein, pilin. A previous study demonstrated that the onset of pilin synthesis occurs well before pili appear on the surface, suggesting that pilin accumulates within the cell. In the present study, an electron microscope immunocytochemistry assay was used to determine the subcellular location of this unassembled pilin and its fate during pilus assembly and cell division. Populations of synchronously growing cells were embedded in epoxy resin at selected times during the cell cycle. Ultrathin sections were treated with pilin-specific antibody, followed by protein A coupled to colloidal gold. It was determined that the cellular location for unassembled pilin was the cell cytoplasm. All cell membranes and regions of nuclear material were poorly labeled. Quantitation demonstrated that label density increased during the period of pilin synthesis and declined during the period of pilus assembly and maintenance. The pilin pool was not unequally segregated at division; e.g., to the daughter cell that is elaborating pili. Mutants which have simultaneously lost the ability to produce flagella, pili, and other polar organdies, possibly due to alterations in the specialized region of polar organelle assembly, were also examined by the immunocytochemistry technique. There was no significant difference in the pilin pool size relative to the wild type, indicating that pilin synthesis continues in the absence of a functioning assembly site. This pattern of synthesis and assembly for the pilus is significantly different from that of the polar flagellum which is produced at the same time and location on the cell surface. These findings are discussed in relation to the hypothesized organization center at the cell pole which may have a major role in directing the assembly of all the polar structures.URING its life cycle, the bacterium Caulobacter crescentus produces several surface structures at a specific location on the cell surface (18, 23). Among the structures produced are a single flagellum, several pili, an adhesive substance (termed a holdfast), and a stalk, fashioned from the membranes that constitute the cell wall of this gram-negative bacterium. In addition, these structures are expressed at a specific time during the life cycle; the flagellum, pili, and holdfast appear simultaneously at the cell pole while the stalk is elaborated at the same position later in the cell cycle. Thus this bacterium provides a distinctive opportunity to study molecular details of gene regulation, morphogenesis, and the mechanisms of directing the assembly of structures to specific sites in a cell.The differentially expressed structures are quite different from one another. The pilus filament is a relatively simple structure, composed of a single protein, pilin (29). Whether there is a basal structure containing additional components is unknown. The flagellum is ...

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“…The genetic determinants responsible for the receptor pili ofPseudomonas aeruginosa (Bradley, 1966) and Caulobacter sp. (Schmidt, 1966) are unknown, but all the RNA phages of Escherichia coli adsorb to F-like pih. In nature, F-pili are produced either constitutively as with F or col V factors, or by cells carrying plasmids whose piln-producing genes have escaped repression by some physiological peculiarity, e.g.…”

Section: Efficiency Ofplatingmentioning

confidence: 99%