Abstract
An electron microscope study of thin sections of interphase cells has revealed the following:— Circular pores are formed in the double nuclear envelope by continuities between the inner and outer membranes which permit contact between the nucleoplasm and the cytoplasm unmediated by a well defined membrane. The pores, seen in sections normal to the nuclear envelope, are profiles of the ring-shaped structures described by others and seen in tangential section. The inner and outer nuclear membranes are continuous with one another and enclose the perinuclear space. The pores contain a diffuse, faintly particulate material. A survey of cells of the rat derived from the embryonic ectoderm, mesoderm, and endoderm, and of a protozoan and an alga has revealed pores in all tissues examined, without exception. It is concluded that pores in the nuclear envelope are a fundamental feature of all resting cells. In certain cells, the outer nuclear membrane is continuous with membranes of the endoplasmic reticulum, hence the perinuclear space is continuous with cavities enclosed by those membranes. There are indications that this is true for all resting cells, at least in a transitory way. On the basis of these observations, the hypothesis is made that two pathways of exchange exist between the nucleus and the cytoplasm; by way of the perinuclear space and cavities of the endoplasmic reticulum and by way of the pores in the nuclear envelope.
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Selected References
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- BAHR G. F., BEERMANN W. The fine structure of the nuclear membrane in the larval salivary gland and midgut of Chironomus. Exp Cell Res. 1954 May;6(2):519–522. doi: 10.1016/0014-4827(54)90200-1. [DOI] [PubMed] [Google Scholar]
- BAIRATI A., LEHMANN F. E. Uber die subroikroskopische Struktur der Kernmembran bei Amoeba proteus. Experientia. 1952 Feb 15;8(2):60–62. doi: 10.1007/BF02139020. [DOI] [PubMed] [Google Scholar]
- CALLAN H. G., TOMLIN S. G. Experimental studies on amphibian oocyte nuclei. I. Investigation of the structure of the nuclear membrane by means of the electron microscope. Proc R Soc Lond B Biol Sci. 1950 Oct 13;137(888):367–378. doi: 10.1098/rspb.1950.0047. [DOI] [PubMed] [Google Scholar]
- DALTON A. J., FELIX M. D. Cytologic and cytochemical characteristics of the Golgi substance of epithelial cells of the epididymis in situ, in homogenates and after isolation. Am J Anat. 1954 Mar;94(2):171–207. doi: 10.1002/aja.1000940202. [DOI] [PubMed] [Google Scholar]
- GALL J. G. Observations on the nuclear membrane with the electron microscope. Exp Cell Res. 1954 Aug;7(1):197–200. doi: 10.1016/0014-4827(54)90054-3. [DOI] [PubMed] [Google Scholar]
- HARRIS P., JAMES T. W. Electron microscope study of the nuclear membrane of Amoeba proteus in thin section. Experientia. 1952 Oct 15;8(10):384–385. doi: 10.1007/BF02176196. [DOI] [PubMed] [Google Scholar]
- HARTMANN J. F. An electron optical study of sections of central nervous system. J Comp Neurol. 1953 Aug;99(1):201–249. doi: 10.1002/cne.900990111. [DOI] [PubMed] [Google Scholar]
- HOGEBOOM G. H., SCHNEIDER W. C. Cytochemical studies. VI. The synthesis of diphosphopyridine nucleotide by liver cell nuclei. J Biol Chem. 1952 May;197(2):611–620. [PubMed] [Google Scholar]
- Hogeboom G. H., Schneider W. C. On the Nuclear Envelope. Science. 1953 Oct 9;118(3067):419–419. doi: 10.1126/science.118.3067.419. [DOI] [PubMed] [Google Scholar]
- PALADE G. E. A small particulate component of the cytoplasm. J Biophys Biochem Cytol. 1955 Jan;1(1):59–68. doi: 10.1083/jcb.1.1.59. [DOI] [PMC free article] [PubMed] [Google Scholar]
- PALADE G. E., PORTER K. R. Studies on the endoplasmic reticulum. I. Its identification in cells in situ. J Exp Med. 1954 Dec 1;100(6):641–656. doi: 10.1084/jem.100.6.641. [DOI] [PMC free article] [PubMed] [Google Scholar]
- PALAY S. L., PALADE G. E. The fine structure of neurons. J Biophys Biochem Cytol. 1955 Jan;1(1):69–88. doi: 10.1083/jcb.1.1.69. [DOI] [PMC free article] [PubMed] [Google Scholar]
- PORTER K. R. Electron microscopy of basophilic components of cytoplasm. J Histochem Cytochem. 1954 Sep;2(5):346–375. doi: 10.1177/2.5.346. [DOI] [PubMed] [Google Scholar]
- PORTER K. R. Observations on a submicroscopic basophilic component of cytoplasm. J Exp Med. 1953 May;97(5):727–750. doi: 10.1084/jem.97.5.727. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SJOSTRAND F. S., HANZON V. Membrane structures of cytoplasm and mitochondria in exocrine cells of mouse pancreas as revealed by high resolution electron microscopy. Exp Cell Res. 1954 Nov;7(2):393–414. doi: 10.1016/s0014-4827(54)80086-3. [DOI] [PubMed] [Google Scholar]
- WATSON M. L. The use of carbon films to support tissue sections for electron microscopy. J Biophys Biochem Cytol. 1955 Mar;1(2):183–184. doi: 10.1083/jcb.1.2.183. [DOI] [PMC free article] [PubMed] [Google Scholar]