title: psoriasis regulates epidermal development in zebrafish.
abstract: The zebrafish epidermis completely envelopes the embryo by 14 hours postfertilization, providing an essential barrier between the internal organs and the environment. As the embryo increases in size, keratinocytes in the epidermis must proliferate and differentiate to form the three epidermal layers present in the adult. The mechanisms controlling growth, differentiation, and maintenance of the fish epidermis are mostly unknown. Here, we describe psoriasis, an epidermal mutant that exhibits widespread overproliferation of the epidermis at 3 days postfertilization and a defect in keratinocyte differentiation. Based on mosaic analysis, we show that psoriasis acts non-cell-autonomously, suggesting that psoriasis encodes a secreted factor. Our analysis of the psoriasis mutant indicates that keratinocyte differentiation and proliferation are tightly regulated to maintain a cohesive epidermal sheet around the embryo and that disruptions in these processes result in the formation of epidermal aggregates.
authors: University of Washington, Department of Biochemistry, Seattle, Washington 98195-7350, USA.
authors: Ashley E
authors: AE
authors: Webb
authors: Wolfgang
authors: W
authors: Driever
authors: David
authors: D
authors: Kimelman
mesh_terms: D000818:Animals; D016923:Cell Death / Q000502:physiology; D002454:Cell Differentiation; D016764:Cell Polarity; D049109:Cell Proliferation; D004817:Epidermis / Q000196:embryology* / Q000254:growth & development / Q000378:metabolism*; D005796:Genes; D015603:Keratinocytes / Q000166:cytology / Q000502:physiology; D007633:Keratins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D015027:Zebrafish / Q000033:anatomy & histology / Q000196:embryology* / Q000235:genetics; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D029961:Zebrafish Proteins; D007633:Keratins