Abstract
With the techniques used in this study, the nucleoid of Streptococcus faecalis could not be seen in freeze-etch preparations unless glutaraldehyde had been added to cultures of cells before they were frozen. With time, the nucleoid became visible as a network of fibers, apparently as a result of the aggregation of individual chromosomal elements in the presence of glutaraldehyde. When glutaraldehyde was added to undisturbed cultures, the fibers that became visible were observed in small patches that were seemingly scattered throughout the cytoplasm. However, if cells were chilled or placed on filters before glutaraldehyde was added, the fibers which then developed were seen in large central areas. The appearance of centralized nucleoids in freeze fractures of cells that had been chilled or filtered could be correlated with a decrease in the central density of the cytoplasm, as seen by light microscopy, in cells embedded in gelatin or bovine serum albumin. These observations are discussed in relation to a model for the normal structure of the nucleoid which suggests that the treatments routinely used to study the morphology-physiology of cells (chilling, filtration, and fixation) result in a reorganization of the cytoplasm, leading to an increase in the centralization of nuclear material.
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- Cronan J. E., Jr Molecular biology of bacterial membrane lipids. Annu Rev Biochem. 1978;47:163–189. doi: 10.1146/annurev.bi.47.070178.001115. [DOI] [PubMed] [Google Scholar]
- Daneo-Moore L., Dicker D., Higgins M. L. Structure of the nucleoid in cells of Streptococcus faecalis. J Bacteriol. 1980 Feb;141(2):928–937. doi: 10.1128/jb.141.2.928-937.1980. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Daneo-Moore L., Higgins M. L. Morphokinetic reaction of Streptococcus faecalis (ATCC 9790) cells to the specific inhibition of macromolecular synthesis: nucleoid condensation on the inhibition of protein synthesis. J Bacteriol. 1972 Mar;109(3):1210–1220. doi: 10.1128/jb.109.3.1210-1220.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Higgins M. L., Shockman G. D. Procaryotic cell division with respect to wall and membranes. CRC Crit Rev Microbiol. 1971 May;1(1):29–72. doi: 10.3109/10408417109104477. [DOI] [PubMed] [Google Scholar]
- Higgins M. L., Tsien H. C., Daneo-Moore L. Organization of mesosomes in fixed and unfixed cells. J Bacteriol. 1976 Sep;127(3):1519–1523. doi: 10.1128/jb.127.3.1519-1523.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kubitschek H. E., Freedman M. L. Chromosome replication and the division cycle of Escherichia coli B-r. J Bacteriol. 1971 Jul;107(1):95–99. doi: 10.1128/jb.107.1.95-99.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Marquis R. E. Immersion refractometry of isolated bacterial cell walls. J Bacteriol. 1973 Dec;116(3):1273–1279. doi: 10.1128/jb.116.3.1273-1279.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Minkoff L., Damadian R. Actin-like properties from Escherichia coli: concept of cytotonus as the missing link between cell metabolism and the biological ion-exchange resin. J Bacteriol. 1976 Jan;125(1):353–365. doi: 10.1128/jb.125.1.353-365.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nanninga N. Structural features of mesosomes (chondrioids) of Bacillu subtilis after freeze-etching. J Cell Biol. 1968 Nov;39(2):251–263. doi: 10.1083/jcb.39.2.251. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tsien H. C., Shockman G. D., Higgins M. L. Structural arrangement of polymers within the wall of Streptococcus faecalis. J Bacteriol. 1978 Jan;133(1):372–386. doi: 10.1128/jb.133.1.372-386.1978. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Woldringh C. L., Nanninga N. Organization of the nucleoplasm in Escherichia coli visualized by phase-contrast light microscopy, freeze fracturing, and thin sectioning. J Bacteriol. 1976 Sep;127(3):1455–1464. doi: 10.1128/jb.127.3.1455-1464.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]