Abstract
The number of pore complexes per nucleus was determined for a wide variety of cultured cells selected for their variable DNA content over a range of 1-5,6000. The pore number was compared to DNA content, nuclear surface area, and nuclear volume. Values for pore frequency (pores/square micrometer) were relatively constant in the species studied. When the pore to DNA ratio was plotted against the DNA content, there was a remarkable correlation which decreased exponentially for the cells of vertebrae origin. Exceptions were the heteroploid mammalian cells which had the same ratio as the diploid mammalian cells despite higher DNA content. The results are interpreted to mean that neither the nuclear surface, the nuclear volume, nor the DNA content alone determines the pore number of the nucleus, but rather an as yet undetermined combination of different factors. The surface and volume of vertebrate nuclei do not decrease with decreasing DNA content below a given value. The following speculation is suggested to account for the anomalous size changes of the nucleus relative to DNA content in vertebrates. Species with small DNA complements have a relatively large proportion of active chromatin which determines the limits of the physical parameters of the nucleus. The amount of active chromatin maybe the same for at least the vertebrates with low DNA content, At high DNA content, the nuclear parameters may be determined by the relatively high proportion of inactive condensed chromatin which increases the nuclear surface and volume.
Full Text
The Full Text of this article is available as a PDF (1.9 MB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bicknell J. N., Douglas H. C. Nucleic acid homologies among species of Saccharomyces. J Bacteriol. 1970 Feb;101(2):505–512. doi: 10.1128/jb.101.2.505-512.1970. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bonner J., Wu J. R. A proposal for the structure of the Drosophila genome. Proc Natl Acad Sci U S A. 1973 Feb;70(2):535–537. doi: 10.1073/pnas.70.2.535. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Deaven L. L., Petersen D. F. Measurements of mammalian cellular DNA and its localization in chromosomes. Methods Cell Biol. 1974;8(0):179–204. [PubMed] [Google Scholar]
- Franke W. W. Nuclear envelopes. Structure and biochemistry of the nuclear envelope. Philos Trans R Soc Lond B Biol Sci. 1974 Jul 25;268(891):67–93. doi: 10.1098/rstb.1974.0016. [DOI] [PubMed] [Google Scholar]
- Franke W. W. On the universality of nuclear pore complex structure. Z Zellforsch Mikrosk Anat. 1970;105(3):405–429. doi: 10.1007/BF00335464. [DOI] [PubMed] [Google Scholar]
- Hartwell L. H. Periodic density fluctuation during the yeast cell cycle and the selection of synchronous cultures. J Bacteriol. 1970 Dec;104(3):1280–1285. doi: 10.1128/jb.104.3.1280-1285.1970. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Holm D. M., Cram L. S. An improved flow microfluorometer for rapid measurement of cell fluorescence. Exp Cell Res. 1973 Jul;80(1):105–110. doi: 10.1016/0014-4827(73)90280-2. [DOI] [PubMed] [Google Scholar]
- Kay R. R., Johnston I. R. The nuclear envelope: current problems of structure and of function. Subcell Biochem. 1973;2(2):127–167. [PubMed] [Google Scholar]
- Kraemer P. M., Petersen D. F., Van Dilla M. A. DNA constancy in heteroploidy and the stem line theory of tumors. Science. 1971 Nov 12;174(4010):714–717. doi: 10.1126/science.174.4010.714. [DOI] [PubMed] [Google Scholar]
- Locke M., Krishnan N., McMahon J. T. A routine method for obtaining high contrast without staining sections. J Cell Biol. 1971 Aug;50(2):540–544. doi: 10.1083/jcb.50.2.540. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Maul G. G., Maul H. M., Scogna J. E., Lieberman M. W., Stein G. S., Hsu B. Y., Borun T. W. Time sequence of nuclear pore formation in phytohemagglutinin-stimulated lymphocytes and in HeLa cells during the cell cycle. J Cell Biol. 1972 Nov;55(2):433–447. doi: 10.1083/jcb.55.2.433. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Maul G. G., Price J. W., Lieberman M. W. Formation and distribution of nuclear pore complexes in interphase. J Cell Biol. 1971 Nov;51(21):405–418. doi: 10.1083/jcb.51.2.405. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SCHERBAUM O. H., LOUDERBACK A. L., JAHN T. L. DNA synthesis, phosphate content and growth in mass and volume in synchronously dividing cells. Exp Cell Res. 1959 Aug;18:150–166. doi: 10.1016/0014-4827(59)90298-8. [DOI] [PubMed] [Google Scholar]
- Teigler D. J., Baerwald R. J. A freeze-etch study of clustered nuclear pores. Tissue Cell. 1972;4(3):447–456. doi: 10.1016/s0040-8166(72)80021-1. [DOI] [PubMed] [Google Scholar]
- Wunderlich F., Wallach D. F., Speth V., Fischer H. Differential effects of temperature on the nuclear and plasma membranes of lymphoid cells. A study by freeze-etch electron microscopy. Biochim Biophys Acta. 1974 Nov 27;373(1):34–43. doi: 10.1016/0005-2736(74)90102-3. [DOI] [PubMed] [Google Scholar]
- Zerban H., Werz G. Changes in frequency and total number of nuclear pores in the life cycle of Acetabularia. Exp Cell Res. 1975 Jul;93(2):472–477. doi: 10.1016/0014-4827(75)90474-7. [DOI] [PubMed] [Google Scholar]