Abstract
The present study on the ultrastructure of Bacillus subtilis was undertaken in order to examine by means of the freeze-etching technique possible structural changes occurring during the chemical fixation procedure (Ryter-Kellenberger (R-K) fixation). Three stages were followed by freeze-etching, viz.: (a) fixation in osmium tetroxide, (b) fixation in osmium tetroxide and posttreatment with uranyl acetate, and (c) fixation in osmium tetroxide, posttreatment in uranyl acetate, and dehydration in a graded series of acetone. Preparations were made after each stage in the presence of 20% glycerol. Good preservation of ultrastructure was observed, after any of the three treatments, of the outer surface of the plasma membrane, and the inner surface of the plasma membrane. No alteration in fracturing properties could be observed. However, if we are to judge by the results of freeze-etching, any of the successive steps of the chemical fixation procedure achieve strong contrast between the nucleoplasmic region and the cytoplasm. Dependent on the quality of fixation, very delicately preserved DNA fibrils or strongly aggregated ones were seen. It appears that R-K fixation is capable of producing more or less distinctly visible changes in the native state of the nucleoplasm in young cells of B. subtilis.
Full Text
The Full Text of this article is available as a PDF (1.3 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Branton D., Southworth D. Fracture faces of frozen Chlorella and Saccharomyces cells. Exp Cell Res. 1967 Sep;47(3):648–653. doi: 10.1016/0014-4827(67)90028-6. [DOI] [PubMed] [Google Scholar]
- Giesbrecht P. Ueber die Tertiärstruktur der DNS in den Chromosomen lebender Zellen. Z Naturforsch B. 1965 Sep;20(9):927–928. [PubMed] [Google Scholar]
- Giesbrecht P. Zur Darstellung der DNS von Bakterien und plastischer biologischer Strukturen mit Hilfe der Gefrierätzung. Zentralbl Bakteriol Orig. 1968;207(2):198–221. [PubMed] [Google Scholar]
- HANNAY C. L. Crystalline inclusions in aerobic spore-forming bacteria. Nature. 1953 Nov 28;172(4387):1004–1004. doi: 10.1038/1721004a0. [DOI] [PubMed] [Google Scholar]
- Lickfeld K. G. Der frostgeätzte Bakterienkern. Ein Beitrag zur Klärung seiner Tertiärstruktur. Z Zellforsch Mikrosk Anat. 1968;88(4):560–564. [PubMed] [Google Scholar]
- Nanninga N. Fine structure observed in 50S ribosomal subunits of Bacillus subtilis. J Cell Biol. 1967 May;33(2):C1–C6. doi: 10.1083/jcb.33.2.c1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nanninga N. The conformation of the 50S ribosomal subunit of Bacillus subtilis. Proc Natl Acad Sci U S A. 1968 Oct;61(2):614–620. doi: 10.1073/pnas.61.2.614. [DOI] [PMC free article] [PubMed] [Google Scholar]
- ROBINOW C. F. The chromatin bodies of bacteria. Bacteriol Rev. 1956 Dec;20(4):207–242. doi: 10.1128/br.20.4.207-242.1956. [DOI] [PMC free article] [PubMed] [Google Scholar]
- RYTER A., KELLENBERGER E., BIRCHANDERSEN A., MAALOE O. Etude au microscope électronique de plasmas contenant de l'acide désoxyribonucliéique. I. Les nucléoides des bactéries en croissance active. Z Naturforsch B. 1958 Sep;13B(9):597–605. [PubMed] [Google Scholar]
- Remsen C. C. Fine structure of the mesosome and nucleoid in frozen-etched Bacillus subtilis. Arch Mikrobiol. 1968;61(1):40–47. doi: 10.1007/BF00704290. [DOI] [PubMed] [Google Scholar]
- Remsen C. C. The fine structure of frozen-etched Bacillus cereus spores. Arch Mikrobiol. 1966 Sep 8;54(3):266–275. doi: 10.1007/BF00408999. [DOI] [PubMed] [Google Scholar]
- STEERE R. L. Electron microscopy of structural detail in frozen biological specimens. J Biophys Biochem Cytol. 1957 Jan 25;3(1):45–60. doi: 10.1083/jcb.3.1.45. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Staehelin L. A. The interpretation of freeze-etched artificial and bilogical membranes. J Ultrastruct Res. 1968 Feb;22(3):326–347. doi: 10.1016/s0022-5320(68)90025-7. [DOI] [PubMed] [Google Scholar]
- VAN ITERSON W., ROBINOW C. F. Observations with the electron microscope on the fine structure of the nuclei of two spherical bacteria. J Biophys Biochem Cytol. 1961 Jan;9:171–181. doi: 10.1083/jcb.9.1.171. [DOI] [PMC free article] [PubMed] [Google Scholar]
- van Iterson W. Symposium on the fine structure and replication of bacteria and their parts. II. Bacterial cytoplasm. Bacteriol Rev. 1965 Sep;29(3):299–325. doi: 10.1128/br.29.3.299-325.1965. [DOI] [PMC free article] [PubMed] [Google Scholar]
- van Iterson W. The fine structure of the ribonucleoprotein in bacterial cytoplasm. J Cell Biol. 1966 Mar;28(3):563–570. doi: 10.1083/jcb.28.3.563. [DOI] [PMC free article] [PubMed] [Google Scholar]