Abstract
The junctional complex in the gill epithelium of the freshwater mussel (Elliptio complanatus) consists of an intermediary junction followed by a 2–3 µ long septate junction. Homologous and heterologous cell pairs are connected by this junction. After fixation with 1% OsO4 containing 1% potassium pyroantimonate, electron microscopy of the gill reveals deposits of electron-opaque precipitate, specifically and consistently localized along cellular membranes. In both junctional and nonjunctional membrane regions, the precipitate usefully outlines the convolutions without obliterating the 150 A intercellular space, which suggests the rarity or absence of either vertebrate-type gap or tight junctions along the entire cell border. The precipitate appears on the cytoplasmic side of the limiting unit membranes of frontal (F), laterofrontal (LF), intermediate (I), lateral (L), and postlateral (PL) cells. The membrane surfaces of certain vesicles of the smooth endoplasmic reticulum, of multivesicular bodies, and of mitochondrial cristae contain precipitate, as does the nucleolus. In other portions of the cell, precipitate is largely absent. The amount of over-all deposition is variable and depends on the treatment of the tissue prior to fixation. Deposition is usually enhanced by pretreatment with 40 mM NaCl as opposed to 40 mM KCl, which suggests that the precipitate is in part sodium pyroantimonate. Treatment with 0.2 mM ouabain does not enhance deposition. Regional differentiation of cell membranes with respect to their ability to precipitate pyroantimonate is found in at least three instances: (a) between the ciliary membranes and other portions of the cell membrane: the precipitate terminates abruptly at the ciliary base, (b) between the LF and I cell borders: the precipitate is asymmetric, favoring the LF side of the junction, and (c) between the septate junctional membrane and adjacent membrane: the precipitate occurs periodically throughout the septate junction region with the periodicity corresponding to the spacing of the septa. This suggests that different regions of the cell membrane may have differing ion permeability properties and, in particular, that the septa may be the regions of high ion permeability in the septate junction.
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- BALINSKY B. I. An electro microscopic investigation of the mechanisms of adhesion of the cells in a sea urchin blastula and gastrula. Exp Cell Res. 1959 Feb;16(2):429–433. doi: 10.1016/0014-4827(59)90275-7. [DOI] [PubMed] [Google Scholar]
- BARGMANN W., von HARNACK, JACOB K. [On the fine structure of the nervous system of the starfish (Asterias rubens L.). I. A contribution to the comparative morphology of the glia]. Z Zellforsch Mikrosk Anat. 1962;56:573–594. [PubMed] [Google Scholar]
- Barros C., Franklin L. E. Behavior of the gamete membranes during sperm entry into the mammalian egg. J Cell Biol. 1968 Jun;37(3):C13–C18. doi: 10.1083/jcb.37.3.c13. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Brightman M. W., Reese T. S. Junctions between intimately apposed cell membranes in the vertebrate brain. J Cell Biol. 1969 Mar;40(3):648–677. doi: 10.1083/jcb.40.3.648. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bulger R. E. Use of potassium pyroantimonate in the localization of sodium ions in rat kidney tissue. J Cell Biol. 1969 Jan;40(1):79–94. doi: 10.1083/jcb.40.1.79. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bullivant S., Loewenstein W. R. Structure of coupled and uncoupled cell junctions. J Cell Biol. 1968 Jun;37(3):621–632. doi: 10.1083/jcb.37.3.621. [DOI] [PMC free article] [PubMed] [Google Scholar]
- CARVALHO A. P., SANUI H., PACE N. CALCIUM AND MAGNESIUM BINDING PROPERTIES OF CELL MEMBRANE MATERIALS. J Cell Physiol. 1963 Dec;62:311–317. doi: 10.1002/jcp.1030620311. [DOI] [PubMed] [Google Scholar]
- Coggeshall R. E. A fine structural analysis of the epidermis of the earthworm, Lumbricus terrestris L. J Cell Biol. 1966 Jan;28(1):95–108. doi: 10.1083/jcb.28.1.95. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Danilova L. V., Rokhlenko K. D., Bodryagina A. V. Electron microscopic study on the structure of septate and comb desmosomes. Z Zellforsch Mikrosk Anat. 1969;100(1):101–117. doi: 10.1007/BF00343824. [DOI] [PubMed] [Google Scholar]
- FARQUHAR M. G., PALADE G. E. Junctional complexes in various epithelia. J Cell Biol. 1963 May;17:375–412. doi: 10.1083/jcb.17.2.375. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Farquhar M. G., Palade G. E. Cell junctions in amphibian skin. J Cell Biol. 1965 Jul;26(1):263–291. doi: 10.1083/jcb.26.1.263. [DOI] [PMC free article] [PubMed] [Google Scholar]
- GIBBONS I. R. The relationship between the fine structure and direction of beat in gill cilia of a lamellibranch mollusc. J Biophys Biochem Cytol. 1961 Oct;11:179–205. doi: 10.1083/jcb.11.1.179. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Goodenough D. A., Revel J. P. A fine structural analysis of intercellular junctions in the mouse liver. J Cell Biol. 1970 May;45(2):272–290. doi: 10.1083/jcb.45.2.272. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KOEHLER J. K. A FINE-STRUCTURE STUDY OF THE ROTIFER INTEGUMENT. J Ultrastruct Res. 1965 Feb;12:113–134. doi: 10.1016/s0022-5320(65)80011-9. [DOI] [PubMed] [Google Scholar]
- Kaye G. I., Cole J. D., Donn A. Electron microscopy: sodium localization in normal and ouabain-treated transporting cells. Science. 1965 Nov 26;150(3700):1167–1168. doi: 10.1126/science.150.3700.1167. [DOI] [PubMed] [Google Scholar]
- Kaye G. I., Wheeler H. O., Whitlock R. T., Lane N. Fluid transport in the rabbit gallbladder. A combined physiological and electron microscopic study. J Cell Biol. 1966 Aug;30(2):237–268. doi: 10.1083/jcb.30.2.237. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Komuro T., Yamamoto T. Fine structure of the epithelium of the gut in the crayfish (Procambarus clarkii) with special reference to the cytoplasmic microtubules. Arch Histol Jpn. 1968 Dec;30(1):17–32. doi: 10.1679/aohc1950.30.17. [DOI] [PubMed] [Google Scholar]
- LOCKE M. THE STRUCTURE OF SEPTATE DESMOSOMES. J Cell Biol. 1965 Apr;25:166–169. doi: 10.1083/jcb.25.1.166. [DOI] [PMC free article] [PubMed] [Google Scholar]
- LOEWENSTEIN W. R., KANNO Y. STUDIES ON AN EPITHELIAL (GLAND) CELL JUNCTION. I. MODIFICATIONS OF SURFACE MEMBRANE PERMEABILITY. J Cell Biol. 1964 Sep;22:565–586. doi: 10.1083/jcb.22.3.565. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lane B. P., Martin E. Electron probe analysis of cationic species in pyroantimonate precipitates in epon-embedded tissue. J Histochem Cytochem. 1969 Feb;17(2):102–106. doi: 10.1177/17.2.102. [DOI] [PubMed] [Google Scholar]
- Lasansky A., Fuortes M. G. The site of origin of electrical responses in visual cells of the leech, Hirudo medicinalis. J Cell Biol. 1969 Jul;42(1):241–252. doi: 10.1083/jcb.42.1.241. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MacRae E. K. The fine structure of sensory receptor processes in the auricular epithelium of the planarian, Dugesia tigrina. Z Zellforsch Mikrosk Anat. 1967;82(4):479–494. doi: 10.1007/BF00337119. [DOI] [PubMed] [Google Scholar]
- SATIR P. STUDIES ON CILIA. THE FIXATION OF THE METACHRONAL WAVE. J Cell Biol. 1963 Aug;18:345–365. doi: 10.1083/jcb.18.2.345. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stuart A. M., Satir P. Morphological and functional aspects of an insect epidermal gland. J Cell Biol. 1968 Mar;36(3):527–549. doi: 10.1083/jcb.36.3.527. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tandler C. J., Libanati C. M., Sanchis C. A. The intracellular localization of inorganic cations with potassium pyroantimonate. Electron microscope and microprobe analysis. J Cell Biol. 1970 May;45(2):355–366. doi: 10.1083/jcb.45.2.355. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tyson G. E. The fine structure of the maxillary gland of the brine shrimp. Artemia salina: the efferent duct. Z Zellforsch Mikrosk Anat. 1969;93(2):151–163. doi: 10.1007/BF00336687. [DOI] [PubMed] [Google Scholar]
- Vinnikov Y. A., Koichev K. Sodium localization in the spiral organ during relative quiet and after exposure to sound. Nature. 1969 Aug 9;223(5206):641–642. doi: 10.1038/223641a0. [DOI] [PubMed] [Google Scholar]
- WIENER J., SPIRO D., LOEWENSTEIN W. R. STUDIES ON AN EPITHELIAL (GLAND) CELL JUNCTION. II. SURFACE STRUCTURE. J Cell Biol. 1964 Sep;22:587–598. doi: 10.1083/jcb.22.3.587. [DOI] [PMC free article] [PubMed] [Google Scholar]
- WOOD R. L. Intercellular attachment in the epithelium of Hydra as revealed by electron microscopy. J Biophys Biochem Cytol. 1959 Dec;6:343–352. doi: 10.1083/jcb.6.3.343. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Welsch U., Storch V. Uber das Osphradium der prosobranchen Schnecken Buccinum undatum L. und Neptunea antiqua (L.) Z Zellforsch Mikrosk Anat. 1969;95(2):317–330. [PubMed] [Google Scholar]