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Avian scale development. VI. Ultrastructure of the keratinizing cells of reticulate scales

✍ Scribed by Roger H. Sawyer; Thomas K. Borg

Publisher
John Wiley and Sons
Year
1979
Tongue
English
Weight
920 KB
Volume
161
Category
Article
ISSN
0362-2525

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✦ Synopsis

Abstract

Reticulate scales develop as radial symmetrical anlagen, in contrast to scuttate scales which appear initially as “epidermal placodes.” Unlike scuttate scales whose outer and inner epidermal surfaces elaborate β‐and α‐type keratins, respectively, reticulate scales elaborate only one type of epidermal surface which has been reported to give an α‐type, X‐ray diffraction pattern. We find that, histologically and ultrastructurally, this surface differs from either epidermal surface of scuttate scales. The keratinizing cells become filled with long interweaving bundles of α‐filaments which aggregate into rather homogeneous α‐fibrils. Keratohyalin granules, which have been shown to be associated with other keratinizing regions in the bird, do not form during the keratinization of reticulate scale epidermis.

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