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. 1998 Feb;192(Pt 2):173–186. doi: 10.1046/j.1469-7580.1998.19220173.x

Differentiation of the epidermis during scale formation in embryos of lizard

LORENZO ALIBARDI 1,✉
PMCID: PMC1467751  PMID: 9643418

Abstract

The formation of the first epidermal generations and in particular of the shedding complex in the developing scales of the lizards Anolis lineatopus and Podarcis muralis was studied by electron microscopy. The initially linear and bilayered epidermis turned into symmetric papillae, which became asymmetric scales. The outer periderm was more electrondense than the following layer, provisionally named ‘inner periderm’ but probably derived from the basal layer. Coarse thick filaments progressively filled the cytoplasm of the inner periderm or formed reticulate bodies resembling avian peridermal granules. Peridermal cells cornified slightly and could be shed in ovo. From the basal layer various suprabasal epithelial layers were produced. The first layer contained keratohyalin-like granules and was identified as a clear layer. Beneath it a spinulated (Anolis) or serrated (Podarcis) oberhäutchen differentiated. The clear and ‘oberhäutchen’ layers constitute the first shedding complex. The first epidermal layers that were shed consisted of flaking periderm or periderm together with the clear layer. The differentiation of a mesos layer was under way before hatching, when the epidermal morphology resembled a stage 4–5 of the adult shedding cycle. Fibroblasts under the inner side of the scale made few contacts with the basement membrane and their cytoplasmic elongations were mostly oriented parallel to the dense lamina. Instead, fibroblasts under the basal layer of the outer scale surface (BLOS) made numerous contacts with the basement membrane, suggesting that more dermal–epidermal interactions take place on this side of the scale.

Keywords: Anolis lineatopus , Podarcis muralis , scale morphogenesis, keratinisation, scale shedding

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Selected References

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  1. Alexander N. J. Comparison of alpha and beta keratin in reptiles. Z Zellforsch Mikrosk Anat. 1970;110(2):153–165. doi: 10.1007/BF00335521. [DOI] [PubMed] [Google Scholar]
  2. Alexander N. J., Parakkal P. F. Formation of alpha- and beta-type keratin in lizard epidermis during the molting cycle. Z Zellforsch Mikrosk Anat. 1969 Oct 1;101(1):72–87. doi: 10.1007/BF00335586. [DOI] [PubMed] [Google Scholar]
  3. Alibardi L. Modifications of the dermis during scale regeneration in the lizard tail. Histol Histopathol. 1994 Oct;9(4):733–745. [PubMed] [Google Scholar]
  4. Alibardi L. Scale morphogenesis during embryonic development in the lizard Anolis lineatopus. J Anat. 1996 Jun;188(Pt 3):713–725. [PMC free article] [PubMed] [Google Scholar]
  5. Downing S. W., Roth S. I. The derivation of the cells of the epidermal strata of the boa constrictor (Constrictor constrictor). J Invest Dermatol. 1974 Apr;62(4):450–457. doi: 10.1111/1523-1747.ep12701696. [DOI] [PubMed] [Google Scholar]
  6. Ernst V., Ruibal R. The structure and development of the digital lamellae of lizards. J Morphol. 1966 Nov;120(3):233–265. doi: 10.1002/jmor.1051200303. [DOI] [PubMed] [Google Scholar]
  7. Flaxman B. A., Maderson P. F. Relationship between pattern of cell migration from the germinal layer and changing patterns of differentiation in the lizard epidermis. J Exp Zool. 1973 Feb;183(2):209–216. doi: 10.1002/jez.1401830209. [DOI] [PubMed] [Google Scholar]
  8. Fuchs E. Epidermal differentiation: the bare essentials. J Cell Biol. 1990 Dec;111(6 Pt 2):2807–2814. doi: 10.1083/jcb.111.6.2807. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. GOSLAR H. G. BEITRAEGE ZUM HAEUTUNGSVORGANG DER SCHLANGEN. 2. STUDIEN ZUR FERMENTTOPOCHEMIE DER KERATOGENESE UND KERATOLYSE AM MODELL DER REPTILIENHAUT. Acta Histochem. 1964 Jan 31;17:1–60. [PubMed] [Google Scholar]
  10. Kallman F., Evans J., Wessells N. K. Anchor filament bundles in embryonic feather germs and skin. J Cell Biol. 1967 Jan;32(1):236–240. doi: 10.1083/jcb.32.1.236. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Liu H. C., Maneely R. B. Observations on the development and regeneration of tail epidermis in Hemidactylus bowringi (Gray). Acta Anat (Basel) 1969;72(4):549–583. doi: 10.1159/000143269. [DOI] [PubMed] [Google Scholar]
  12. Maderson P. F., Flaxman B. A., Roth S. I., Szabo G. Ultrastructural contributions to the identification of cell types in the lizard epidermal generation. J Morphol. 1972 Feb;136(2):191–209. doi: 10.1002/jmor.1051360205. [DOI] [PubMed] [Google Scholar]
  13. Matoltsy A. G. The molecular and developmental biology of keratins. Concluding remarks and future directions. Curr Top Dev Biol. 1987;22:255–264. [PubMed] [Google Scholar]
  14. Matulionis D. H. Morphology of the developing down feathers of chick embryos. A descriptive study at the ultrastructural level of differentiation and keratinization. Z Anat Entwicklungsgesch. 1970;132(2):107–157. doi: 10.1007/BF00523275. [DOI] [PubMed] [Google Scholar]
  15. Miscalencu D. Ulastructural modifications in the keratinization process of the intermediate-layer cells in the epidermis of Natrix natrix (L.). Acta Anat (Basel) 1974;87(3):375–384. [PubMed] [Google Scholar]
  16. Mottet N. K., Jensen H. M. The differentiation of chick embryonic skin. An electron microscopic study with a description of a peculiar epidermal cytoplasmic ultrastructure. Exp Cell Res. 1968 Sep;52(1):261–283. doi: 10.1016/0014-4827(68)90564-8. [DOI] [PubMed] [Google Scholar]
  17. Parakkal P. F., Matoltsy A. G. An electron microscopic study of developing chick skin. J Ultrastruct Res. 1968 Jun;23(5):403–416. doi: 10.1016/s0022-5320(68)80106-6. [DOI] [PubMed] [Google Scholar]
  18. Roth S. I., Jones W. A. The ultrastructure of epidermal maturation in the skin of the boa constrictor (Constrictor constrictor). J Ultrastruct Res. 1970 Jul;32(1):69–93. doi: 10.1016/s0022-5320(70)80038-7. [DOI] [PubMed] [Google Scholar]
  19. Ruibal R., Ernst V. The structure of the digital setae of lizards. J Morphol. 1965 Nov;117(3):271–293. doi: 10.1002/jmor.1051170302. [DOI] [PubMed] [Google Scholar]
  20. Sawyer R. H., Abbott U. K., Fry G. N. Avian scale development. III. Ultrastructure of the keratinizing cells of the outer and inner epidermal surfaces of the scale ridge. J Exp Zool. 1974 Oct;190(1):57–70. doi: 10.1002/jez.1401900105. [DOI] [PubMed] [Google Scholar]

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