title: Dlx genes integrate positive and negative signals during feather bud development.
abstract: In the embryonic chicken skin, feather buds and the intervening interbud tissue form in a reiterated and sequential pattern that is dependent on interactions between the epidermis and dermis. Feather promoting and inhibiting signals such as fibroblast growth factors (FGF) and bone morphogenetic proteins (BMP), respectively, direct the formation of this periodic pattern. However, the transcription factors that mediate the response to these signals and transmit this information to downstream effector genes are largely unknown. Here we have explored the DLX transcription factors as candidate transcriptional mediators downstream of the described feather patterning signals. We show that several Dlx members are expressed in the dermis and epidermis of the developing feather buds and their expression is induced in embryonic chick skin by the ectopic activation of BMP and FGF signaling. Misexpression of Dlx in the chick skin leads to both feather loss and feather bud fusions, suggesting that DLX proteins play a negative as well as a positive role in feather development. Moreover, DLX regulates the expression of NCAM and tenascin, molecules that are important for feather bud initiation as well as bud outgrowth and morphogenesis. Our results suggest that DLX transcription factors serve to integrate and transduce feather patterning signals to downstream effector molecules.
authors.affiliation: Howard Hughes Medical Institute and Developmental Biology Program, Sloan-Kettering Institute and Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA.
authors.forename: Iaroslava
authors.initials: I
authors.lastname: Rouzankina
authors.forename: Cory
authors.initials: C
authors.lastname: Abate-Shen
authors.forename: Lee
authors.initials: L
authors.lastname: Niswander
mesh_terms: D000818:Animals; D002642:Chick Embryo; D004627:Embryonic Induction; D005241:Feathers / Q000196:embryology*; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics* / Q000502:physiology; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008954:Models, Biological; D019006:Neural Cell Adhesion Molecules / Q000502:physiology; D015398:Signal Transduction; D012867:Skin / Q000196:embryology; D019063:Tenascin / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics* / Q000502:physiology
chemical_list: C088334:Distal-less homeobox proteins; D018398:Homeodomain Proteins; D019006:Neural Cell Adhesion Molecules; D019063:Tenascin; D014157:Transcription Factors