Summary
Previous X-ray diffraction studies have established the crystallographic identity of tunicin with cellulose from plant cell walls. Enzymatic degradation of the tunicin results in the isolation of microfibrils 120–130 Å in width (which appear to consist of two sub-units). Using staining and freeze-etching techniques it has been demonstrated that the microfibrils occur in the test as aggregates measuring 2000–4000 Å in diameter. In this respect the physical texture of the cellulose ofPyura resembles that of collagen in animal connective tissue and does not resemble the texture of cellulose in either the primary or secondary cell walls of plants.
Examination of fixed and frozen etched specimens showed that ferrocytes of the test and vesicles derived from them are closely associated with the cellulose microfibril bundles. However, at the optical level, autoradiographs of animals treated with C14 glucose showed greatest radioactivity to be in the epidermal cells of the mantle and of the blood vessels, but not in the ferrocytes. These cells also showed a considerable development of rough ER and of Golgi bodies. On the evidence obtained it is considered that the sites of cellulose synthesis are the epidermal cells of the mantle and of the blood vessels. The function of the test cells is unknown. The migration of ferrocytes to areas of wounding in the test suggests that they may have some lytic function associated with wound repair.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Anderson, T. F., 1951: Trans. N.Y. Acad. Sci.13, 130–134.
Berrill, N. J., 1950: TheTunicata Ray Society, London.
Brien, P., 1930: Ann. Soc. Roy. Zool. Belg. LXI61, 19–112.
Deck, David J., Elizabeth D. Hay, andJean-Paul Revel, 1966: J. Morphology120 (3), 267–280.
Endean, R., 1955 a: Aust. J. Marine and Freshwater Res.6, 35–59.
—, 1955 b: Aust. J. Marine and Freshwater Res.6, 139–156.
—, 1955 c: Aust. J. Marine and Freshwater Res.6, 157–164.
—, 1961: Quart. J. Microscopical Sci.102, 107–117.
Frey-Wyssling, A., andR. Frey, 1950: Protoplasma39, 656–660.
—, andK. Mühlethaler, 1963: Makromol. Chem.62, 25.
Glauert, A. M., andR. H. Glauert, 1958: J. biophys. biochem. Cytol.4, 191.
Hall, D. A., andH. Saxl, 1961: Proc. Roy. Soc. (Lond.)B 155, 202–217.
Hecht, S., 1918: J. Exp. Zool.25, 229–260.
Herzog, R., andH. W. Gonell, 1924: Z. physiol. Chem.141, 63–67.
Kelsey, K. E., 1963: The structure and properties of tunicin with special reference to drying and shrinkage, Internal Report, C.S.I.R.O. Division of Forest Products, Melbourne, Australia.
Mark, H., andG. v. Susich, 1929: Z. physik. Chem.4, 431.
Maser, M. D., T. P. O'Brien, andMcCully, 1967: J. de Microscopie6, 305–312.
Mishra, A. K., and J. R.Colvin, 1969: Canad. J. Zoology (in press) (Private communication).
Moor, H., 1964: Z. Zeilforsch.62, 546–580.
Porter, K. R., 1959: J. biophys. biochem. Cytol.5, 153–166.
Ränby, B. G., 1952: Arkiv. for Kemi4 (13), 241–248.
Ross, R., 1968: Biol. Rev.43 (1), 51–96.
Sutra, R., 1932: Compt. rend.195, 181.
Wardrop, A. B., andS. M. Jutte, 1968: Wood Sci. and Technol.2, 105–114.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wardrop, A.B. The structure and formation of the test ofPyura stolonifera (Tunicata) . Protoplasma 70, 73–86 (1970). https://doi.org/10.1007/BF01276843
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF01276843