Summary
What appear to be two types of unicellular glands are found in the integument of the leech, Helobdella stagnalis. Type I cells are characterized by a peripheral, subplasmalemmal sack of rough endoplasmic reticulum and accumulations of secretory product in the form of small membrane bound droplets. Type II cells are characterized by large numbers of closely opposed sacks of rough endoplasmic reticulum and secretory product in the form of large, evidently amorphous accumulations of secretory product.
Both cell types attenuate into long, slender processes through which the secretory product passes to the surface of the leech. Each process is characterized by a subplasmalemmal sack of ER which runs the entire length of the process and is continuous, at the proximal end of the process, with sacks of rough ER. Associated with the inner member of the ER membrane pair are microtubules with a diameter of approximately 240 Å.
A similar arrangement of a subplasmalemmal ER sack associated with microtubules also is found in secretory processes of the leech, Macrobdella decora.
The possible source and functions of these microtubules are discussed.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bawa, S. R.: Electron microscope study of spermiogenesis in a fire-brat insect, Thermobia domestica (Pack). J. Cell Biol. 23, 431–446 (1964).
Bayer, E.: Hypodermis und neue Hautsinnesorgane der Rhynchobdelliden. Z. wiss. Zool. 64, 648–696 (1898).
Behnke, O.: A preliminary report on “microtubules” in undifferentiated and differentiated vertebrate cells. J. Ultrastruct. Res. 11, 139–146 (1964).
Bradke, D. L.: Membranous modifications for intracellular transport of secretory product. Abstracts of the 2nd Annual Meeting of the A.S.C.B. 22, 1962.
—: A unique invertebrate photoreceptor. In: Electron microscopy. Proceedings of the 5th Internat. Congr. for Electron Microscopy, vol. II: R-5. New York, Academic 1963.
—: Special features of spermatogenesis in Lumbricus terrestris. Anat. Rec. 145, 360 (1963).
-In press (1965).
de-Thé, G.: Cytoplasmic microtubules in different animal cells. J. Cell Biol. 23, 265–275 (1964).
Fawcett, D. W., and P. Witebsky: Observations on the ultrastructure of nucleated erythrocytes and thrombocytes, with particular reference to the structural basis of their discoidal shape. Z. Zellforsch. 62, 785–806 (1964).
Grimstone, A. V., and L. R. Cleveland: The fine structure and function of the contractile axostyles of certain flagellates. J. Cell Biol. 24, 387–400 (1965).
Harris, P., and D. Mazia: The finer structure of the mitotic apparatus. In: The interpretation of ultrastructure (ed. by) R. J. C. Harris, p. 279–306. New York: Academic Press, Inc. 1962.
Leuckart, R.: Die menschlichen Parasiten und die von ihnen herrührenden Krankheiten. Leipzig u. Heidelberg: C. F. Winter 1893.
—: Die Parasiten des Menschen und die von ihnen herrührenden Krankheiten. Leipzig: C. F. Winter 1886–1901.
Luft, J. H.: Improvements in epoxy resin embedding methods. J. biophys. biochem. Cytol. 9, 409–414 (1961).
Mann, K. T.: Leeches (Hirudinea). New York: Pergamon Press 1962.
Maser, M. D., and C. W. Philpott: Marginal bands in nucleated erythrocytes. Anat. Rec. 150, 365–382 (1964).
Overton, J.: Intercellular connections in the outgrowing stolon of Cordylophora. J. Cell Biol. 17, 661–671 (1963).
Palade, G. E.: A study of fixation for electron microscopy. J. exp. Med. 95, 285 (1952).
Palay, S. L.: Synapses in the central nervous system. J. biophys. biochem. Cytol. 2, Suppl. 193–208 (1956).
Reynolds, E. S.: The use of lead citrate at high p H as an electron-opaque stain in electron microscopy. J. Cell Biol. 17, 208–212 (1963).
Robbins, E., and N. K. Gonatas: The ultrastructure of a mammalian cell during the mitotic cycle. J. Cell Biol. 21, 429–263 (1964).
Roth, L. E., and E. W. Daniels: Electron microscopic studies of mitosis in amebae. J. Cell Biol. 12, 57–78 (1962).
Sandborn, E., P. F. Koen, J. D. McNabb, and G. Moore: Cytoplasmic microtubules in mammalian cells. J. Ultrastruct. Res. 11, 123–138 (1964).
Scriban, I. A., u. H. Autrum: Hirudinea. In: Handbuch der Zoologie, Bd. 2/II, S. 119–352. Berlin u. Leipzig: W. d. Gruyter & Co. 1934.
Silvera, M., and K. R. Porter: The spermatozoids of flatworms and their microtubular systems. Protoplasma (Wien) 59, 240–265 (1964).
Slautterback, D. B.: Cytoplasmic microtubules. I. Hydra. J. Cell Biol. 18, 367–388 (1963).
Wiener, J., D. Spiro, and W. R. Loewenstein: Studies on an epithelial (gland) cell junction. II. Surface structure J. Cell Biol. 22, 587–598 (1964).
Wood, R. L.: Intercellular attachments in the epithelium of Hydra as revealed by electron microscopy. J. biophysic. biochem. Cytol. 6, 343–352 (1959).
Author information
Authors and Affiliations
Additional information
This investigation was supported by Public Health Service grant number GM 723-04 of the National Institutes of Health.
The author is greatly indebted to Dr. David B. Slautterback for his advice and encouragement during the course of this investigation.
Rights and permissions
About this article
Cite this article
Clark, A.W. Microtubules in some unicellular glands of two leeches. Zeitschrift für Zellforschung 68, 568–588 (1965). https://doi.org/10.1007/BF00347717
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00347717