Abstract
The ultrastructure and chemical composition of reflective organelles in the anterior pigment epithelium of the iris of the European starling Sturnus vulgaris were examined. The reflective organelles produced a diffuse white reflectance at the iris mid-section which was visible only when the stroma was removed. The pigment granules were clear, angular, and birefringent under the light microscope. In electron micrographs the granules were irregular in shape and density, sometimes crystalline in appearance, but more often they were lost during sectioning or staining. Guanine was abundant in the modified pigment epithelium of the starling, but not in the pigment epithelia of other birds that lacked birefringent granules. Pteridines, such as xanthopterin and leucopterin, were present in small amounts. Pteridines were also present in the iris stroma which had no reflective organelles. The reflective organelles in the starling pigment epithelium resemble both the reflecting platelets of lower vertebrate chromatophores and the reflective granules in the tapeta of various vertebrates. Possible derivation of the organelles from these sources is discussed.
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References
Arnott HJ, Nicol JAC, Querfeld CW (1972) Tapela lucida in the eyes of the seatrout (Sciaenidae). Proc R Soc Lond [Biol] 180:247–271
Bagnara JT, Hadley ME (1973) Chromatophores and color change. Prentice-Hall, Englewood Cliffs
Bagnara JT, Matsumoto J, Ferris W, Frost SK, Turner WA, Tchen TT, Taylor JD (1979) The common origin of pigment cells. Science 203:410–415
Barden RB (1942) The origin and development of the chromatophores of the amphibian eye. J Exp Zool 90:479–519
Best ACG, Nicol JAC (1967) Reflecting cells of the elasmobranch tapetum lucidum. Contrib Mar Sci Univ Tex 12:172–201
Best ACG, Nicol JAC (1979) On the eye of the goldeye Hiodon alosoides (Teleostei: Hiodontidae). J Zool (Lond) 188:309–332
Duke-Elder S (1963) System of ophthalmology: normal and abnormal development, vol 3. Klimpton, London
Ferris W, Bagnara JT (1972) Reflecting pigment cells in the dove iris. In: Riley V (ed) Pigmentation: its genesis and biologic control. Appleton-Century-Crofts, New York, pp 181–192
Fukushima T, Nixon JC (1980) Chromatographic analysis of pteridines. Methods Enzymol 66:429–436
Henze M, Rempeters G, Anders F (1977) Pteridines in the skin of xiphophorine fish (Poeciliidae). Comp Biochem Physiol [B] 56:35–46
Ide H (1978) Transformation of amphibian xanthophores into melanophores in clonal cultures. J Exp Zool 203:287–294
Ide H, Hama T (1976) Transformation of amphibian iridophores into melanophores in clonal culture. Develop Biol 53:297–302
Lesiuk TP, Braekevelt CR (1983) Fine structure of the canine tapetum lucidum. J Anat 136:157–164
Lopashov GV, Stroeva OG (1964) Development of the eye. Experimental studies (translated by B. Meytar). S. Monson, Jerusalem
Mann I (1964) The development of the human eye. Grune and Stratton, New York
Matsumoto J (1965) Role of pteridines in the pigmentation of chromatophores in cyprinid fish. Jpn J Zool 14:45–95
Matsumoto J, Wada K, Akiyama T (1989) Neural crest cell differentiation and carcinogenesis: capability of goldfish erythrophoma cells for multiple differentiation and clonal polymorphism in their melanogenic variants. J Invest Dermatol [Suppl] 92:255–260
Nicol JAC (1989) The eyes of fishes Clarendon Press, Oxford
Nicol JAC, Arnott HJ (1974) Tapeta lucida in the eyes of goatsuckers (Caprimulgidae). Proc R Soc Lond [Biol] 187:349–352
Nicol JAC, Arnott HJ, Best ACG (1973) Tapeta lucida in bony fishes (Actinopterygii): a survey. Can J Zool 51:69–81
Oehme H (1969) Vergleichende Untersuchungen über die Färbung der Vogeliris. Biol Zentralbl 88:3–35
Oliphant LW (1987) Observations on the pigmentation of the pigeon iris. Pigment Cell Res 1:202–208
Oliphant LW (1988) Cytology and pigments of non-melanophore chromatophores in the avian iris. In: Bagnara JT (ed) Advances in pigment cell research. Liss, New York, pp 65–82
Oliphant LW, Hudon J (1993) Pteridines as reflecting pigments and components of reflecting organelles in vertebrates. Pigment Cell Res 6:205–208
Oliphant LW, Hudon J, Bagnara JT (1992) Pigment cell refugia in homeotherms — the unique evolutionary position of the iris. Pigment Cell Res 5:367–371
Pirie A (1961) Cholesterol in the tapetum lucidum of the eyes of the opossum, Didelphis virginiana. Nature 191:708–709
Ris H (1941) An experimental study of the origin of melanophores in birds. Physiol Zool 14:48–69
Sweijd N, Craig AJFK (1991) Histological basis of age-related changes in iris color in the African pied starling (Spreo bicolor). The Auk 108:53–59
Walls G (1942) The vertebrate eye and its adaptive radiation. Cranbrook Institute of Science, Bloomfield Hills
Zyznar ES, Ali MA (1975) An interpretative study of the organization of the visual cells and tapetum lucidum of Stizostedion. Can J Zool 53:180–196
Zyznar ES, Nicol JA (1973) Reflecting materials in the eyes of three teleosts, Orthopristes chrysopterus, Dorosoma cepedianum and Anchoa mitchilli. Proc R Soc Lond [Biol] 184:15–27
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Hudon, J., Oliphant, L.W. Reflective organelles in the anterior pigment epithelium of the iris of the European starling Sturnus vulgaris . Cell Tissue Res 280, 383–389 (1995). https://doi.org/10.1007/BF00307811
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DOI: https://doi.org/10.1007/BF00307811