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Epidermal transient down‐regulation of retinol ‐ binding protein 4 and mirror expression of apolipoprotein Eb and estrogen receptor 2a during zebrafish fin and scale development
Author(s) -
TingaudSequeira Angèle,
Forgue Jean,
André Michèle,
Babin Patrick J.
Publication year - 2006
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.20921
Subject(s) - biology , epidermis (zoology) , morphogenesis , zebrafish , microbiology and biotechnology , danio , anatomy , genetics , gene
Very little is known about the molecular control of skin patterning and scale morphogenesis in teleost fish. We have found radially symmetrical epidermal placodes with down‐regulation of retinol ‐ binding protein 4 ( rbp4 ) expression during the initial paired fin and scale morphogenesis in zebrafish ( Danio rerio ). This finding may be related to changes in keratinocyte cytodifferentiation and/or the integument retinoid metabolism. rbp4 transcripts are expressed afterward in the central epidermis of the scale papilla and gradually extend to the epidermis, covering the growing scale, whereas no transcripts were detected in posterior margin epidermis. In contrast, induction of apolipoprotein Eb ( apoeb ) and up‐regulation of estrogen receptor 2a ( esr2a ) transcripts were observed in the epidermis at initiator sites of zebrafish ectodermal/dermal appendage morphogenesis. This expression was maintained in the posterior margin epidermis of the formed scales. esr2a was also strongly expressed in neuromasts, whereas no rbp4 and apoeb transcripts were detected in these mechanosensory structures. The observed epidermal molecular events suggest that epidermis patterning is due to an activator–inhibitor mechanism operational at epidermal–dermal interaction sites. rbp4 transcript expression was also strongly down‐regulated by 1‐phenyl‐2‐thio‐urea (PTU). As this inhibitor is commonly used to block obscuring pigmentation during in situ hybridization studies, this finding suggests that PTU should be used with caution, particularly in studying skin development. Developmental Dynamics 235:3071–3079, 2006. © 2006 Wiley‐Liss, Inc.