Summary
The pattern of morphogenesis of the chitinous compound (jointed) setae of the larvae of polychaete Nereis vexillosa Grube was deduced from electron-microscopic analyses of many stages of secretion. Each seta is secreted over a period of three days within an epidermal follicle consisting of several lateral cells and a basal cell (chaetoblast). The configuration of the apical surface of the chaetoblast changes continuously during secretion. Secreted setal material is polymerized into longitudinally oriented setal filaments, probably by enzymes located on the surfaces of microvilli of the chaetoblast. As a result of this process the setae lengthen by basal appositional growth. We infer that the precise size and shape of each complex seta (a characteristic of the species and the age of the worm) is controlled by sequential modulations of the number, size, shape, arrangement and orientation of the microvilli of the chaetoblast. Each seta embodies a cryptic record of the activities of the chaetoblast on which it formed. The genetic and epigenetic mechanisms involved in chaetogenesis are problematic.
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References
Bobin, G.: Etude de soies simples et de leurs bulbes sétigères chez deux Sabelliens. Trav. Stat. Biol. Roscoff 13, 155–175 (1935)
Bobin, G.: Morphologie exacte des soies chez quelques Annélides Polychètes. Bull. Soc. Zool. France 67, 61–65 (1942)
Bobin, G.: Morphogénèse des soies chez Annélides Polychètes. Ann. Inst. Ocean., Monaco 22, 1–106 (1944)
Bobin, G.: Histologie et cytologie des bulbes setigérès d'Euphrosyne foliosa Audouin et M. Edwards (Annélide Polychète). Arch. Zool. Exp. Gén., Notes det Revue, 85, 138–150 (1948)
Bobin, G., Mazoué. H.: Topographie, histologie, caractères physiques et chimiques d'Aphrodite aculeata L. (Annélide Polychète). Bull. Soc. Zool. France 69, 125–134 (1944)
Bouligand, Y.: Etude ultrastructurale des soies et des cellules associées chez une annélide polychète Haplosyllis depressa. C. R. Acad, Sci. (Paris) 263D, 378–381 (1966)
Bouligand, Y.: Les soies et les cellules associées chez deux annélides polychètes. Etude en mioroscopie photonique à contraste de phase et en microscopie électronique. Z. Zellforsch. 79, 332–363 (1967)
Dennell, R.: Earthworm chaetae. Nature (Lond.) 164, 370 (1949)
Ebling, F. J.: Formation and nature of the operculate chaetae of Sahellaria alveolata. Quart. J. micr. Sci. 85, 153–176 (1945)
Fedotov, D. M.: Die Anatomie von Protomyzostomum polynephris Fedotov. Z. wiss. Zool. 109, 631–696 (1914)
George, J. D., Southward, E. C.: A comparative study of the setae of pogonophora and polychaetous annelida. J. Mar. Biol. Ass. U. K. 53, 403–422 (1973)
Gustus, R. M.: Patterns of morphogenesis mediated by dynamic microvilli: A study of chaetogenesis in invertebrates. Ph. D. Thesis, University of Washington (1973)
Gustus, R. M., Cloney, R. A.: Ultrastructure of the larval compound setae of the polychaete Nereis vexillosa Grube. J. Morph. 140, 355–366 (1973)
Gustus, R. M., Cloney, R. A.: The role of microvilli in determining the specific shape of polychaete setae. Proc. Amer. Soc. Cell Biol., 11th Ann. Mtg., p. 113 (1971)
Jagersten, G.: Zur Kenntnis der Parapodialborsten bei Myzostomum. Zool. Bidr. Uppsala 16, 283–299 (1937)
Lippert, W., Gentil, K.: Über den Feinbau der Schillerhaare des Polychaeten Aphrodite aculeata L. Z. Morphol. Ökol. Tiere 53, 22–28 (1963)
Lubischew, A.: Structure and development of bristles of polychaeta. Bull. Inst. Recherch. Biol. Univ. Perm. 2, 306–314 (1924)
Luft, J. H.: Improvements in epoxy resin embedding methods. J. biophys. biochem. Cytol. 9, 409–414 (1961)
Neville, A. C.: Chitin orientation in cuticle and its control. In: Advances in insect physiology, J.W.L. Beament, J. E. Treherne and V. B. Wigglesworth, eds., vol. 4, p. 213–286. New York: Academic Press 1967
Orrhage, L.: Light and electron microscope studies of some annelid setae. Acta zool. Stockh. 52, 157–169 (1971)
Picken, L.E.R., Lotmar, W.: Oriented protein in chitinous structures. Nature (Lond.) 165, 599–600 (1950)
Potswald, H. E.: A fine structural analysis of the epidermis and cuticle of the oligochaete Aeolosoma bengalense Stephenson. J. Morph. 135, 185–212 (1971)
Pruvot, G.: Sur la structure et la formation des soies de Nereis. 9ième Contrès Intern. Zool. Monaco, 348–355 (1913)
Reynolds, E. S.: The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J. Cell Biol. 23, 111A (1963)
Richardon, K. C., Jarrett, L., Pinke, E. H.: Embedding in epoxy-resins for ultrathin sectioning in electron microscopy. Stain Technol. 35, 313–323 (1960)
Rudall, K. M.: The chitin/protein complexes of insect cuticles. In: J.W.L. Beament, J. E. Treherne and V. B. Wigglesworth (eds.), Advances in insect physiology, vol. 1, p. 257–313. New York: Academic Press 1963
Schepotieff, A.: Untersuchungen über die Borstentaschen einiger Polychäten. Z. wiss. Zool. 77, 586–605 (1904)
Schroeder, P. C.: Morphogenesis of epitokous setae during normal and induced metamorphosis in the polychaete annelid Nereis grubei (Kinberg). Biol. Bull. 132, 426–437 (1967)
Thuneberg, L., Rostgaard, J.: Motility of microvilli, a film demonstration. J. Ultrastruct. Res. 29, 578 (1969)
Tilney, L. G., Cardell, R. R.: Factors controlling the reassembly of the microvillous border of the small intestine of the salamander. J. Cell Biol. 47, 408–422 (1970)
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Formerly Rita M. Gustus.
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O'Clair, R.M., Cloney, R.A. Patterns of morphogenesis mediated by dynamic microvilli: Chaetogenesis in Nereis vexillosa . Cell Tissue Res. 151, 141–157 (1974). https://doi.org/10.1007/BF00222219
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DOI: https://doi.org/10.1007/BF00222219