title: Dorsal dermis of the scaleless (sc/sc) embryo directs normal feather pattern formation until day 8 of development.
abstract: We have examined the ability of the scaleless (sc/sc) backskin dermis (6 to 16 days of incubation) to regulate pattern formation using the presumptive scutate scale epidermis from 11-day normal embryos as the responding tissue. Prior to 8 days of incubation the sc/sc backskin dermis is able to induce hexagonally patterned and uniformly oriented feather germs in normal epidermis. This ability is lost during day 8 and follows a central to lateral gradient. Such gradients are characteristic of normal feather development in the spinal tract. We discuss the change in the inductive ability of the sc/sc dermis in relation to the stabilization of the feather pattern, which occurs all at once throughout the dorsal dermis at 7.5-8 days of development. After day 8 until day 10, the sc/sc backskin dermis only supports the formation of sporadic, unpatterned feather germs; thereafter it will not support feather formation.
authors.affiliation: Cutaneous Biology Research Center, Massachusetts General Hospital, Charlestown 02129, USA.
authors.forename: H K
authors.initials: HK
authors.lastname: Song
authors.forename: R H
authors.initials: RH
authors.lastname: Sawyer
mesh_terms: D000818:Animals; D002642:Chick Embryo; D046508:Culture Techniques; D005241:Feathers / Q000196:embryology*; D018507:Gene Expression Regulation, Developmental; D009154:Mutation; D011995:Recombination, Genetic; D012867:Skin / Q000196:embryology*; D013997:Time Factors