Formation of α- and β-type keratin in lizard epidermis during the molting cycle

  • Nancy J. Alexander
  • Paul F. Parakkal
Article

Summary

The epidermis of Anolis carolinensis is renewed periodically by molting. Prior to the molt the distinct layers of the epidermis, namely, the Oberhäutchen, β, mesos, and α layers, are formed in sequence from a morphologically homogenous population of basal cells. The Oberhäutchen, the first cell layer to form, has spinules on the surface which interdigitate with the overlying cells of the clear layer. The cells of the Oberhäutchen develop 80 Å filaments similar to those in the cells of the α layer. Beneath the Oberhäutchen is the β layer, the cells of which develop membrane-bounded packets containing a homogenous material during the early stages of differentiation. Later 100–500 Å thick fibrils are formed in the membranebounded packets. The fully keratinized cells, however, are packed with filaments 30 Å in diameter separated by an electron dense amorphous matrix, very similar to β-type keratin found in the feather rachis. The cells of the α layer, which is immediately below the β layer, contain 80 Å filaments very similar to the α-type keratin found in hair cortex and keratinizing stratified epithelia of mammals. Large quantities of glycogen are found in the cells of each layer during their genesis. Even though a stratum granulosum is not found underneath the α layer, the cells of the clear layer develop bodies which have histochemical and ultrastructural characteristics of keratohyalin granules. The old epidermis is then shed in toto at the junction of the clear layer (above) and the Oberhäutchen (below).

Key-Words

Cell differentiation Keratin Electron microscopy Reptiles Skin 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Alexander, N. J., and W. H. Fahrenbach: The dermal chromatophores of Anolis carolinensis (Reptilia, Iguanidae). Amer. J. Anat. 126, 41–56 (1969).Google Scholar
  2. Baden, H. P., S. I. Roth, and L. C. Bonar: Fibrous proteins of snake scale. Nature (Lond.) 212, 498–499 (1966).Google Scholar
  3. Bell, E., and Y. T. Thathachari: Development of feather keratin during embryogenesis of the chick. J. Cell Biol. 16, 215–223 (1963).Google Scholar
  4. Birbeck, M. S. C., and E. H. Mercer: The electron microscopy of human hair follicle. Part I. Introduction and hair cortex. J. biophys. biochem. Cytol. 3, 203–214 (1957).Google Scholar
  5. Bonneville, M. A.: Observations on epidermal differentiation in the fetal rat. Amer. J. Anat. 123, 147–164 (1968).Google Scholar
  6. Brody, I.: An ultrastructural study on the role of the keratohyalin granules in the keratinization process. J. Ultrastruct. Res. 2, 84–104 (1959a).Google Scholar
  7. —: The keratinization of epidermal cells of normal guinea pig skin as revealed by electron microscopy. J. Ultrastruct Res. 2, 482–511 (1959b).Google Scholar
  8. —: The ultrastructure of the tonofibrils in the keratinizing process of normal human epidermis. J. Ultrastruct. Res. 4, 264–297 (1960).Google Scholar
  9. Bryant, S. V., A. S. Breathnach, and D. A. Bellairs: Ultrastructure of the epidermis of the lizard (Lacerta vivipara) at the resting stage of the sloughing cycle. J. Zool. 152, 209–219 (1967).Google Scholar
  10. Daniels, P., Jr., D. Brophy, and W. C. Lobitz Jr.: Histochemical response of human skin following ultraviolet irradiation. J. invest. Derm. 37, 351–357 (1961).Google Scholar
  11. Ernst, V., and R. Ruibal: The structure and development of the digital lamellae of lizards. J. Morph. 120, 233–266 (1966).Google Scholar
  12. Farbman, A. I.: Morphological variability of keratohyalin. Anat. Rec. 154, 275–286 (1966).Google Scholar
  13. Filshie, B. K., and G. E. Rogers: The fine structure of α-keratin. J. molec. Biol. 3, 784–786 (1961).Google Scholar
  14. —: An electron microscope study of the fine structure of feather keratin. J. biophys. biochem. Cytol. 13, 1–12 (1962).Google Scholar
  15. Flaxman, B. A., P. F. A. Maderson, G. Szabó, and S. I. Roth: Control of cell differentiation in lizard epidermis in vitro. Develop. Biol. 18, 354–374 (1968).Google Scholar
  16. Fukuyama, K., and W. Epstein: Ultrastructural autoradiographic studies of keratohyalin granule formation. J. invest. Derm. 49, 595–604 (1967).Google Scholar
  17. Giacometti, L.: The healing of skin wounds in primates. I. The kinetics of cell proliferation. J. invest. Derm. 48, 133–137 (1967).Google Scholar
  18. Henrikson, R. C., and A. G. Matoltsy: The fine structure of teleost epidermis. I. Introduction and filament containing cells. J. Ultrastruct. Res. 21, 194–212 (1968).Google Scholar
  19. Hiller, U.: Untersuchungen zum Feinbau und zur Funktion der Haltborsten von Reptilien. Z. Morph. Tiere 62, 307–362 (1967).Google Scholar
  20. Horstmann, E.: Elektronenmikroskopische Untersuchungen an der Epidermis von Reptilien. Anat. Anz. 113, 87–93 (1964).Google Scholar
  21. Lillywhite, H. B., and P. F. A. Maderson: Histological changes in the epidermis of the subdigital lamellae of Anolis carolinensis during the shedding cycle. J. Morph. 125, 379–402 (1968).Google Scholar
  22. Lobitz, W. C. Jr., and J. B. Holyoke: The histochemical response of the human epidermis to controlled injury: Glycogen. J. invest. Derm. 22, 189–198 (1954).Google Scholar
  23. Lundgren, H. P., and W. H. Ward: The keratins. In: Ultrastructure of protein fibers (R. R. Borasky, ed.), p. 39–122. New York: Academic Press, Inc. 1963.Google Scholar
  24. Maderson, P. F. A.: The skin of lizards and snakes. Brit. J. Herp. 3, 151–154 (1964).Google Scholar
  25. —: Histological changes in the epidermis of snakes during the sloughing cycle. J. Zool. 146, 98–113 (1965a).Google Scholar
  26. —: The structure and development of the squamate epidermis. In: Biology of the Skin and Hair Growth (A. G. Lyne and B. F. Short, ed.), p. 129–152. Sidney: Angus and Robertson 1965b.Google Scholar
  27. —: Histological changes in the epidermis of the tokay (Gekko gecko) during the sloughing cycle. J. Morph. 119, 39–50 (1966).Google Scholar
  28. —, and P. Licht: Epidermal morphology and sloughing frequency in normal and prolactin treated Anolis carolinensis. J. Morph. 123, 157–172 (1967).Google Scholar
  29. Matoltsy, A. G., and P. F. Parakkal: Keratinization. In: Ultrastructure of Normal and Abnormal Skin (A. Zelickson, ed.), p. 76–104. Philadelphia: Lea and Febiger 1968.Google Scholar
  30. Mercer, E. H.: Keratin and Keratinization. 316 pp. New York: Pergamon Press, Inc. 1961.Google Scholar
  31. Montagna, W.: The Structure and Function of Skin. 454 pp. New York: Academic Press, Inc. 1962.Google Scholar
  32. Mottet, N. K., and H. M. Jensen: The differentiation of chick embryonic skin. Exp. Cell Res. 52, 261–283 (1968).Google Scholar
  33. Odland, G. F.: Tonofilaments and keratohyalin. In: The Epidermis. (W. Montagna and W. C. Lobitz, ed.), p. 237–249. New York: Academic Press, Inc. 1964.Google Scholar
  34. Parakkal, P. F.: The fine structure of anagen hair follicle of the mouse. In: Advances in Biology of Skin. IX. Hair Growth (W. Montagna, ed.), p. 441–469. Oxford: Pergamon Press 1969.Google Scholar
  35. —, and A. G. Matoltsy: A study of the fine structure of the epidermis of Rana pipiens. J. Cell Biol. 20, 85–94 (1964).Google Scholar
  36. —: An electron microscopic study of developing chick skin. J. Ultrastruct. Res. 23, 403–416 (1968).Google Scholar
  37. Rogers, G. E.: Structural and biochemical features of the hair follicle. In: The Epidermis (W. Montagna and W. C. Lobitz, ed.), p. 179–232. New York: Academic Press, Inc. 1964.Google Scholar
  38. Roth, S. I., and W. A. Jones: The ultrastructure and enzymatic activity of the boa constrictor (Constrictor constrictor) skin during the resting phase. J. Ultrastruct. Res. 18, 304–323 (1967).Google Scholar
  39. Rudall, K. M.: X-ray studies of the distribution of protein chain types in the vertebrate epidermis. Biochem. biophys. Acta (Amst.) 1, 549–562 (1947).Google Scholar
  40. Ruibal, R., and V. Ernst: The structure of digital setae of lizards. J. Morph. 117, 271–294 (1965).Google Scholar
  41. Spearman, R. I. C.: The keratinization of epidermal scales, feathers and hairs. Biol. Rev. 41, 59–96 (1966).Google Scholar
  42. Voute, C. L.: An electron microscopic study of the skin of the frog (Rana pipiens). J. Ultrastruct. Res. 9, 497–510 (1963).Google Scholar
  43. Wellings, S. R., R. G. Chuinard, and R. A. Cooper: Ultrastructural studies of normal skin and epidermal papillomas of the flat-head sole (Hippoglossoides elassodon). Z. Zellforsch. 78, 370–387 (1967).Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 1969

Authors and Affiliations

  • Nancy J. Alexander
    • 1
  • Paul F. Parakkal
    • 1
  1. 1.Oregon Regional Primate Research CenterBeavertonUSA

Personalised recommendations