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  • 1
    Electronic Resource
    Electronic Resource
    Cytoskeletal Architecture of Dermal Chromatophores of the Freshwater Teleost Oryzias latipes (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Periodontology 2000 6 (1993), S. 0 
    Details
    ISSN: 1600-0757
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Cytoskeletal construction of dermal chromatophores of Orgzias latipes was studied by immunofluorescence microscopy. A microtubule system was most prominent in melanophores where a large number of microtubules emanated from the center of the cell. Xanthophores had an arrangement basically similar to that of melanophores, though the radial pattern became more irregular in the peripheral region where intersecting wavy microtubules were quite frequent. Oval-shaped leucophores exhibited the least-developed microtubule system, where the limited number of microtubules formed a loose basket-like architecture. Intermediate filaments were ubiquitously present in all types of chromatophores and were found to be vimentin-immunoreactive. Examination of doubly-labeled cells indicated that vimentin filaments had similar distribution patterns with microtubules. Orderly arranged bundles of actin filaments were found only in xanthophores, while in melanophores and xanthophores, actin expression was diffuse without displaying a conspicuous filamentous organization. Colchicine treatment induced depolymerization of microtubules and retraction of dendrites in varying degrees in cells in culture and in situ. Melanophores in culture are very sensitive to the treatment while xanthophores appeared to be more resistant in respect to the maintenance of cell morphology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-0749.1993.tb00624.x
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  • 2
    Electronic Resource
    Electronic Resource
    Melanosome Formation in Cultured Amelanotic Melanophores of Rana brevipoda by a Frog Tyrosinase cDNA Transfection (1995)
    Oxford, UK : Blackwell Publishing Ltd
    Periodontology 2000 8 (1995), S. 0 
    Details
    ISSN: 1600-0757
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: A cDNA encoding tyrosinase of Rana nigromaculata was introduced into cultured, tyrosinase-negative amelanotic melanophores of R. brevipoda by a calcium phosphate precipitation method. Within a few days following transfection, dark pigmentation became visible in a small number of cells. Light microscopic observation revealed that the morphology of these transformed cells was comparable to that of normal melanophores in culture, and their proliferative activity was lower than that of amelanotic cells. Ultrastructural examination verified that amelanotic melanophores possessed a relatively small number of premelanosomes while the transformants contained numerous melanosomes at various stages of pigment deposition. The result indicated that tyrosinase cDNA of R. nigromaculata was expressed in amelanotic melanophores of R. brevipoda inducing the maturation of premelanosomes. It was also suggested that the expression of transfected tyrosinase cDNA had promoted differentiation of the amelanotic cells into fully developed melanophores.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-0749.1995.tb00662.x
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  • 3
    Electronic Resource
    Electronic Resource
    N-CAM and N-Cadherin Are Specifically Expressed in Xanthophores, but not in the Other Types of Pigment Cells, Melanophores, and Iridiphores (1995)
    Oxford, UK : Blackwell Publishing Ltd
    Periodontology 2000 8 (1995), S. 0 
    Details
    ISSN: 1600-0757
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Little is known about cell-cell communication in pigment cells, whereas a number of signalling molecules have been implicated to control their migration, differentiation, and proliferation. We set out to investigate the expression of cell adhesion molecules (CAMs) in the three different types of pigment cells in poikilotherms, Oryzias latipes and Xenopus laevis. In the present experiments, the expression of N-CAM and N-cadherin in the pigment cells in vitro was examined by immunocytochemistry. Melanophores and xanthophores were isolated and cultured from scales or skins, while iridophores were harvested from skins or peritoneum. The results showed that N-CAM and N-cadherin were specifically expressed in xanthophores, but not in melanophores or iridophores in both O.latipes and X.laevis. N-CAM and N-cadherin basically colocalized in the restricted regions of xanthophores, although the N-cadherin-expressed region was broader than the N-CAM-expressed region in the same cell. The incidence of N-cadherin expression was higher than that of N-CAM expression. N-CAM and N-cadherin were expressed at the tip or the base of dendrites, or at the edge between dendrites in dendritic xanthophores. N-CAM and N-cadherin usually localized in small and narrow regions of xanthophores. This distribution pattern was essentially similar in xanthophores with round morphology, which exhibited spot, band, or semicircular immunoreactive regions on the peripheral edge of the cells. The difference in the distribution of pigment granules within the cells, culture period, fixatives, or immunofluorescent markers used in the experiments did not alter the immunostaining pattern.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-0749.1995.tb00768.x
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  • 4
    Electronic Resource
    Electronic Resource
    Dermal and Epidermal Chromatophores of the Antarctic Teleost Trematomus bernacchii (1990)
    Oxford, UK : Blackwell Publishing Ltd
    Periodontology 2000 3 (1990), S. 0 
    Details
    ISSN: 1600-0757
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The physiological response and ultrastructure of the pigment cells of Trematomus bernacchii, an Antarctic teleost that lives under the sea ice north of the Ross Ice Shelf, were studied. In the integument, two types of epidermal chromatophores, melanophores and xanthophores, were found; in the dermis, typically three types of chromatophores—melanophores, xanthophores, and iridophores—were observed. The occurrence of epidermal xanthophore is reported for the first time in fish. Dermal melanophores and xanthophores have well-developed arrays of cytoplasmic microtubules. They responded rapidly to epinephrine and teleost melanin-concentrating hormone (MCH) with pigment aggregation and to theophylline with pigment dispersion. Total darkness elicited pigment aggregation in the majority of dermal xanthophores of isolated scales, whereas melanophores remained dispersed under both light and dark conditions. Pigment organelles of epidermal and dermal xanthophores that translocate during the pigmentary responses are carotenoid droplets of relatively large size. Dermal iridophores containing large reflecting platelets appeared to be immobile.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1600-0749.1990.tb00259.x
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  • 5
    Electronic Resource
    Electronic Resource
    Pterin Synthesis in the Amphibian Neural Crest Cell (1960)
    [s.l.] : Nature Publishing Group
    Nature 187 (1960), S. 326-327 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Pterin Fractions in the Middle Neurula and Larva. As a preliminary experiment, qualitative determinations were made of pterins in the neurula, where pigment cells had not yet differentiated, and in the larva, having well-developed melanophores and xanthophores in the trunk area. 30 intact middle ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/187326a0
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  • 6
    Electronic Resource
    Electronic Resource
    Actin microfilaments in melanophores of Fundulus heteroclitus (1978)
    Springer
    Cell & tissue research 193 (1978), S. 387-397 
    Details
    ISSN: 1432-0878
    Keywords: Microfilaments ; Actin ; Melanophores ; Melanosome translocation ; Fundulus heteroclitus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary In melanophores of Fundulus heteroclitus, hormone-stimulated melanosome aggregation is accompanied by cytoplasmic flow from the cellular processes to the perikaryon, and reversal of these events takes place upon hormone-induced melanosome dispersion. These cells contain parallel arrays of microtubules, the majority of which are located in the perikaryon and in cortical regions of the processes. Studies with heavy meromyosin binding demonstrated two types of actin filaments: 1) a decorated meshwork of filaments similar to those usually found in close association with plasma membranes, and 2) filaments decorated in a manner similar to that of stress fibers. There is an apparent increase in the amount of filaments during melanosome aggregation. These results are discussed in relation to intracellular movement.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00225337
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  • 7
    Electronic Resource
    Electronic Resource
    Formation of pterinosomes and carotenoid granules in xanthophores of the teleost Oryzias latipes as revealed by the rapid-freezing and freeze-substitution method (1993)
    Springer
    Cell & tissue research 271 (1993), S. 81-86 
    Details
    ISSN: 1432-0878
    Keywords: Xanthophores ; Pterinosomes ; Carotenoid vesicles ; Rapid-freezing ; Freeze-substitution ; Oryzias latipes (Teleostei)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The rapid-freezing and freeze-substitution method was applied for the ultrastructural study of the dermal chromatophores of a teleost, Oryzias latipes. The method was found to be suitable for preserving fragile membranous structures within melanophores and xanthophores. In addition, relatively high electron density in overall profile indicates that the procedure is effective in reducing the extraction of cytoplasmic ground substances that inevitably occurs during the process of conventional chemical fixation and the following dehydration. The improved ultrastructural images clearly show that the pterinosomes, the characteristic pigmentary organelles of xanthophores, are formed through several distinct developmental stages starting from the loose congregations of vesicles derived from the Golgi complex. The earlier stages of development are similar to those found in melanosome formation. Whereas carotenoid pigments in xanthophores in conventional aldehyde-osmium-fixed materials are found to be electrondense membrane-free particles, they are identified as membrane-bounded organelles in the present study. The envelope of these carotenoid vesicles does not exhibit a typical trilaminar structure but appears to be an extremely thin membrane. Carotenoid vesicles are, in most cases, in direct contact with the outer surface of tubular endoplasmic reticulum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00297544
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  • 8
    Electronic Resource
    Electronic Resource
    Ultrastructure of microtubules in dermal melanophores and spinal nerve of the Antarctic teleost Pagothenia borchgrevinki (1986)
    Springer
    Cell & tissue research 244 (1986), S. 339-343 
    Details
    ISSN: 1432-0878
    Keywords: Dermal melanophores ; Antarctic teleost ; Pagothenia borchgrevinki ; Melanosome migration ; Cold-resistant microtubules ; Spinal nerves
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The antarctic teleost, Pagothenia borchgrevinki inhabits the Antarctic Ocean where the water temperature remains around -1.9° C throughout the year. Dermal melanophores of this fish respond within minutes to epinephrine and theophylline with melanosome aggregation and dispersion, respectively. Numerous cytoplasmic microtubules are present in these cells despite the low environmental temperature. In longitudinal profiles, many microtubules are twisted, beaded and sometimes even branched. In cross sections, C-, U-, S-, 6- and other irregularly shaped tubules are observed. Nocodazole partially disrupts microtubules and inhibits epinephrine-induced pigment aggregation. Pigment movements are also prevented by erythro-9-[3-(2-hydroxynonyl)] adenine. Although the participation of these incomplete microtubules in cell motility remains uncertain, the results indicate that this fish has a cold-resistant microtubule system on which melanosome movements depend. Unlike those in melanophores, microtubules in the axons of spinal nerves are of uniform thickness and often contain an electron-dense core in the center.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219209
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  • 9
    Electronic Resource
    Electronic Resource
    Ultrastructural demonstration of hormone-induced movement of carotenoid droplets and endoplasmic reticulum in xanthophores of the goldfish, Carassius auratus L. (1978)
    Springer
    Cell & tissue research 190 (1978), S. 409-416 
    Details
    ISSN: 1432-0878
    Keywords: Endoplasmic reticulum ; Actin filaments ; Xanthophores ; Pigment cells
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The hormone-induced pigment dispersion in primary cultures of xanthophores of goldfish (Carassius auratus L.) has been shown to involve the dispersion of not only carotenoid droplets but also of smooth endoplasmic reticulum. The dispersion of these organelles is inhibited by cytochalasin B and is accompanied by thinning of the cell body, thickening of the processes, and also overall changes in cellular morphology (process extension) under certain conditions. Electron microscopic examination of heavy meromyosin treated glycerinated xanthophores in scales revealed the presence of actin filaments in these cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00219555
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  • 10
    Electronic Resource
    Electronic Resource
    Histological distribution of pterins in the skin of bull-frogSupported by the Scientific Research Fund of the Ministry of Education and a grant from Keio-Gijuku University. (1959)
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 134 (1959), S. 25-36 
    Details
    ISSN: 0003-276X
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/ar.1091340104
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