title: Regulation of chick early B-cell factor-1 gene expression in feather development.
abstract: The chick Ebf1 (early B-cell factor-1) gene is a member of a novel family of helix loop helix transcription factors. The expression profile, regulation and significance of this gene have been extensively studied in lymphatic, nervous, adipose and muscular tissues. However, cEbf1 expression, regulation and function in the feather of chick embryo have not yet been investigated. cEbf1 expression was first detected throughout the mesenchymal core of some few feather placodes (D7-D7.5). After feathers became mature and grew distally (D9 and D10), the mesenchymal expression of cEbf1 became confined to the caudal margin of the proximal half of all formed feather buds. Because this dynamic pattern of expression resembles that of Sonic Hedgehog (Shh) protein and bone morphogenetic protein (Bmp4) plus the crucial role of these two major signals in feather development, we hypothesized that cEbf1 expression in the feather may be regulated by Shh and Bmp4. In a feather explant culture system, Shh signals are necessary to initiate and maintain cEbf1 expression in the posterior half of the feather bud, while Bmp4 is crucial for the initial cEbf1 expression in the anterior half of the feather bud. Inhibition of Shh, not only down-regulates cEbf1, but also changes the morphology of feather buds, which become irregular and fused. This is the first study to demonstrate that cEbf1 expression in the feather bud is under the control of Shh and Bmp4 signals and that expression may play a role in the normal development of feathers.
authors.affiliation: Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Kafrelsheikh University, Egypt.
authors.forename: Mohammed Abu
authors.initials: MA
authors.lastname: El-Magd
authors.affiliation: Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Damanhour University, Egypt. Electronic address: afiomy@yahoo.com.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Sayed-Ahmed
authors.affiliation: Department of Animal Wealth Development, Faculty of Veterinary Medicine, Zagazig University, Egypt.
authors.forename: Ashraf
authors.initials: A
authors.lastname: Awad
authors.affiliation: Department of Physiology, Faculty Veterinary Medicine, Kafrelsheikh University, Egypt.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Shukry
mesh_terms: D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000378:metabolism; D002642:Chick Embryo; D005241:Feathers / Q000196:embryology / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D053823:Hedgehog Proteins / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*
chemical_list: D019485:Bone Morphogenetic Proteins; D053823:Hedgehog Proteins; D015534:Trans-Activators
keywords: Bone morphogenetic protein 4; Chick embryo; Early B-cell factor 1; Feathers; Sonic Hedgehog