This investigation was supported by research grant GB-11569 from the National Science Foundation awarded to Dr. Yoshihiro Kato, and in part by a USPHS predoctoral fellowship (1-F01-GM 42799-01). This study constituted a portion of a dissertation presented as partial fulfillment of the requirements for the degree of Doctor of Philosophy.
Avian scale development. I. Histogenesis and morphogenesis of the epidermis and dermis during formation of the scale ridge†
Article first published online: 3 MAY 2005
Copyright © 1972 Wiley-Liss, Inc., A Wiley Company
Journal of Experimental Zoology
Volume 181, Issue 3, pages 365–383, September 1972
How to Cite
Sawyer, R. H. (1972), Avian scale development. I. Histogenesis and morphogenesis of the epidermis and dermis during formation of the scale ridge. J. Exp. Zool., 181: 365–383. doi: 10.1002/jez.1401810307
- Issue published online: 3 MAY 2005
- Article first published online: 3 MAY 2005
Scale development in the chick embryo can be considered as consisting of two major phases. First, a definitive scale ridge is formed from a simple two-layered epidermis. This phase consists of five stages: preplacode, placode, asymmetrical placode, hump stage, and definitive scale ridge. The second phase involves the elongation of the definitive scale ridge to give rise to the overlapping scales of the adult bird. During elongation a new (inner) epidermal surface is formed, which is histologically less differentiated than the outer epidermal surface. A timed-sequence study has shown that the placode gives rise mainly to the outer epidermal surface of the definitive scale ridge, while the inter-placode region becomes the thinner epidermis at the scale apex.