Regulation of Bacterial Sporogenesis

Szulmajster, Jekisiel

doi:10.1007/978-3-642-68833-1_12

Cited by 4 publications

(3 citation statements)

References 39 publications

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“…Possibly these initiations are scheduled by a clocklike process that is a normal feature of vegetative growth and which is in some way related to cell age. This could be the source of the distribution of times at which spore septum formation (stage II) is reached (34). It seems plausible that when initiations occur after the onset of starvation, the chromosomes are "modified" by a special mechanism so that they participate in sporogenesis.…”

Section: Discussionmentioning

confidence: 99%

Chromosome Replication in Sporulating Cells of Bacillus subtilis

Sargent

1980

J Bacteriol

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A method of specifically labeling the chromosomal terminus of Bacillus subtilis is described. When sporulating cultures were pulse-labeled with [ 3 H]thymidine and then treated with 6-( p -hydroxyphenylazo)uracil, a drug which inhibits deoxyribonucleic acid (DNA) synthesis rapidly and completely, the only labeled spores formed were those that had completed replication during the pulse period. DNA-mediated transformation was used to show that the DNA of spores formed in the presence of 6-( p -hydroxyphenylazo)uracil had the same ratio of origin to terminus markers as DNA from untreated spores. Furthermore, spores formed in the presence of 6-( p -hydroxyphenylazo)uracil had the same DNA content as untreated spores. These two observations indicated that spores formed in the presence of 6-(hydroxyphenylazo)uracil contained completed chromosomes. The rate of termination of chromosomes destined to be packaged into spores was determined by this method, using the Sterlini-Mandelstam replacement system and a single medium exhaustion system for inducing sporulation. With both systems the rate of termination reached a broad peak 2 h after the start of sporogenesis. This was measured from the time of resuspension by using the replacement system and from the point where exponential growth ceased in the exhaustion system. The amount of spore DNA synthesized in the Sterlini-Mandelstam sporulation-inducing medium was very close to one-half the amount of the DNA present in mature spores. This suggests that chromosomes destined to be packaged into spores were replicated from close to the origin and possibly initiated in the sporulation-inducing medium. A method was devised for estimating the time taken to complete replication of the chromosomes destined to be packaged into spores. This was probably no more than 50 min. Whereas starvation must have occurred almost simultaneously in most cells in the population, the chromosome replication that was essential for sporogenesis was distributed over a wide time span. Thus, in some cells, replication started within 10 min of the nutritional step-down, but the peak rate was not reached for 1 h; thereafter replication continued at a substantial rate.

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Section: Discussionmentioning

confidence: 99%

Chromosome Replication in Sporulating Cells of Bacillus subtilis

Sargent

1980

J Bacteriol

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“…Thus, at stage IV the spores have formed cortex and become phase bright, but if the medium is enriched, germination and outgrowth occur while the spores are still in the mother cells. This has been demonstrated in B. cereus (6) and B. subtilis (5,22). Dion et al (5) described the germination and outgrowth of stage IV prespores as slow and very asynchronous.…”

mentioning

confidence: 87%

“…(i) At stage II, if a culture of Bacillus cereus or Bacillus subtilis is enriched with fresh medium, the spore septum turns into an ordinary division septum. The result is two contiguous cells, both of which begin to grow (8,22). The picture is somewhat confused because some authors (9, 10) believe that the prespore at stage II does not possess the capacity for outgrowth.…”

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confidence: 99%

Germination properties as marker events characterizing later stages of Bacillus subtilis spore formation

Dion¹,

Mandelstam²

1980

J Bacteriol

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At various stages during spore fonnation sporangia were shocked by cold treatment or with toluene, and the germination requirements of the prespores were examined. Up to 5 h after induction of sporulation (t5) germination was spontaneous; i.e., it occurred without any added germinants. After t5, during stages V and VI, the capacity for spontaneous germination diminished progressively, and the spores acquired a need for externally added germinants. At tc this need was satisfied by either L-alanine or a mixture of KC1, glucose, and fructose. By t8, the latter response had disappeared. The spores germinated only with Lalanine, and the response was much slower. Experiments with chloramphenicol showed that the germination properties of the spores appearing between t6 and te were the expression of events in protein synthesis that had occurred before t5. Although the germination requirements developed at about the same time as heat resistance, they could be dissociated from heat resistance in wild-type and mutant cells.The germination properties of the developing spores are additional marker events characterizing the later stages of sporulation, as follows: (i) spontaneous germination (up to the end of stage IV); (ii) germination requirements that are satisfied by KCl-glucose-fructose or L-alamnie (stage V); and (iii) slow germination response with L-alamine only (stage VI).

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Differenzierung und Musterbildung bei einfachen Organismen

Jaenicke

1990

Differenzierung Und Musterbildung Bei Einfachen Organismen. Kurzlebige Isotope in Der Pflanzenphysiologie Am Beispiel Des 11c-R

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Regulation of Bacterial Sporogenesis

Cited by 4 publications

References 39 publications

Chromosome Replication in Sporulating Cells of Bacillus subtilis

Chromosome Replication in Sporulating Cells of Bacillus subtilis

Germination properties as marker events characterizing later stages of Bacillus subtilis spore formation

Differenzierung und Musterbildung bei einfachen Organismen

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