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Cone photoreceptors lacking oil droplets in the retina of the echinda, Tachyglossus aculeatus (Monotremata)

Published online by Cambridge University Press:  02 June 2009

Heather M. Young
Affiliation:
Vision Touch and Hearing Research Centre, Department of Physiology and Pharmacology, University of Queensland, 4072, Queensland, Australia
John D. Pettigrew
Affiliation:
Vision Touch and Hearing Research Centre, Department of Physiology and Pharmacology, University of Queensland, 4072, Queensland, Australia

Abstract

The echidna, Tachyglossus aculeatus, a monotreme mammal, is thought to possess an all-rod retina (O' Day, 1952). This study provides anatomical evidence for the presence of cone-like photoreceptors in the retina of the echidna. The cones, which constitute 10–15% of the photoreceptors, have all of the ultrastructural characteristics previously shown in the cones of placental mammals, and, like the cones of other animals (Blanks & Johnson, 1984), they bind peanut agglutinin. Unlike the cones of another monotreme, the platypus, the cones of the echidna retina do not possess oil droplets. Twin cones, pairs of cones in which there is no obvious difference in the size, shape, or ultrastructural features of the members of a pair, are common. The density of cones varies from 9000 cells/mm2 in the superior periphery to 22,000 cells/mm2 in the central retina. Nearest-neighbor analysis suggests that the cone mosaic in the echidna retina results from the presence of single and twin cones in a relatively regular array.

Type
Research Articles
Copyright
Copyright © Cambridge University Press 1991

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References

Archer, M., Flannery, T.F., Ritchie, A. & Molnar, R.E. (1985). First Mesozoic mammal from Australia – an early Cretaceous monotreme. Nature 318, 363366.Google Scholar
Augee, M.L. (1983). Short-beaked echidna. In Australian Museum Complete Book of Australian Mammals, ed. Strahan, R. pp. 89. London: Angus & Robertson.Google Scholar
Blanks, J.C. & Johnson, L.V. (1984). Specific binding of peanut lectin to a class of retinal photoreceptor cells. A species comparison. Investigative Ophthalmology and Visual Science 25, 546557.Google Scholar
Braekevelt, C.R. (1973). Fine structure of the retinal pigment epithelium and photoreceptor cells of an Australian marsupial (Setonix brachyurus). Canadian Journal of Zoology 51, 10931100.Google Scholar
Cohen, A.I. (1972). Rods and cones. In Handbook of Sensory Physiology, VII/2: Physiology of Photoreceptor Organs, ed. Fuortes, M.G.F., pp. 63110. Berlin: Springer-Verlag.CrossRefGoogle Scholar
Crescitelli, F. (1972). The visual cells and visual pigments of the vertebrate eye. In Handbook of Sensory Physiology, VII/I: Photochemistry of Vision, ed. Dartnall, H.J.A., pp. 245363. Berlin: Springer-Verlag.Google Scholar
Gates, R.G. (1979). Vision in the monotreme echidna (Tachyglossus aculeatus). Australian Zoology 20, 147170.Google Scholar
Griffiths, M. (1978). The Biology of the Monotremes. New York: Academic Press.Google Scholar
Gunn, M. (1884). On the eye of Ornithorhynchus paradoxus. Journal of Anatomy and Physiology 17, 400405.Google Scholar
Haberman, S.J. (1973). The analysis of residuals in cross-classified tables. Biometrics 29, 205220.Google Scholar
Hailman, J.P. (1976). Oil droplets in the eyes of adult anuran amphibians: a comparative study. Journal of Morphology 148, 453468.CrossRefGoogle Scholar
Hughes, A. (1971). Topographic relationships between the anatomy and physiology of the rabbit visual system. Documenta Ophthalmologica 30, 33159.Google Scholar
Hughes, A. (1977). The topography of vision in mammals of contrasting lifestyle: comparative optics and retinal organization. In Handbook of Sensory Physiology, VII/5: The Visual System of Vertebrates, ed. Crescitelli, F. pp. 697756. Berlin: Springer- Verlag.Google Scholar
Jacobs, G.H., Tootell, R.B.H., Fisher, S.K. & Anderson, D.H. (1980). Rod photoreceptors and scotopic vision in ground squirrels. Journal of Comparative Neurology 189, 113125.Google Scholar
Jerison, H.J. (1974). Evolution of Brain and Intelligence. London: Academic Press.Google Scholar
Johnson, J.I., Switzer, R.C. & Kirsch, J.A.W. (1982). Phylogeny through brain traits: the distribution of categorizing characters in contemporary mammals. Brain Behavior and Evolution 20 97117.Google Scholar
Kolb, H. & Wang, H.H. (1985). The distribution of photoreceptors, dopaminergic amacrine cells, and ganglion cells in the retina of the North American opossum (Didelphis virginiana). Vision Research 25, 12071221.Google Scholar
Long, K.O. & Fisher, S.K. (1983). The distributions of photoreceptors and ganglion cells in the California ground squirrel, Spermophilus beecheyi. Journal of Comparative Neurology 221, 329340.Google Scholar
McLean, I.W. & Nakane, P.K. (1974). Periodate-lysine-paraformal dehyde fixative. A new fixative for immunoelectron microscopy. Journal of Histochemistry and Cytochemistry 22, 10771083.Google Scholar
Murray, R.G., Jones, A.E. & Murray, A. (1973). Fine structure of photoreceptors in the owl monkey. Anatomical Record 175, 673696.Google Scholar
O'day, K. (1935). A preliminary note on the presence of double cones and oil droplets in the retina of marsupials. Journal of Anatomy 70, 465467.Google Scholar
O'day, K. (1938a). The retinal of the Australian marsupial. Medical Journal of Australia 1, 326328.Google Scholar
O'day, K. (1938b). The visual cells of the platypus (Ornithorhyncus). British Journal of Ophthalmology 22, 321328.Google Scholar
O'day, K.J. (1952). Observations on the eye of the monotreme. Transactions of the Ophthalmological Society of Australia 12, 95104.Google Scholar
Odgen, T.E. (1975). The receptor mosaic of Aotes trivirgalus: distribution of rods and cones. Journal of Comparative Neurology 163, 193202.Google Scholar
Pettigrew, J.D., Jamieson, B.G.M., Robson, S.K., Hall, L.S., Mcanally, K.I. & Cooper, H.M. (1989). Phylogenetic relationships between microbats, megabats, and primates (Mammalia: Chiroptera and Primates). Philosophical Transactions of the Royal Society (London) 325, 489559.Google Scholar
Röhlich, P., Szé, A., Johnson, L.V. & Hageman, G.S. (1989). Carbohydrate components recognized by the cone-specific monoclonal antibody CSA-1 and by peanut agglutinin are associated with red- and green-sensitive cone photoreceptors. Journal of Comparative Neurology 289, 395400.Google Scholar
Stone, J. (1983). Topographic organization of the retina in a monotreme: Australian spiny anteater Tachyglossus aculeatus. Brain Behavior and Evolution 22, 175184.Google Scholar
Walls, G.L. (1942). The Vertebrate Eye and its Adaptive Radiation. New York: Hafner Publishing Company.Google Scholar
Wässle, H. & Riemann, H.J. (1978). The mosaic of nerve cells in the mammalian retina. Proceedings of the Royal Society B (London) 200, 441461.Google Scholar
West, R.W. & Dowling, J.E. (1975). Anatomical evidence for cone- and rod-like receptors in the gray squirrel, ground squirrel, and prairie dog retinas. Journal of Comparative Neurology 159, 439460.Google Scholar
Wong, R.O.L. (1989). Morphology and distribution of neurons in the retina of the American garter snake (Thamnophis sirtalis). Journal of Comparative Neurology 283, 587601.Google Scholar
Young, H.M. & Vaney, D.I. (1990). The retinae of prototherian mammals possess neuronal types that are characteristic of nonmammalian retinae. Visual Neuroscience 5, 6166.Google Scholar