The aim of this study was to show the existence of epidermal-dermal interac
tions during dermal scales regeneration to analyse their functions at the m
orphological and cytological level and to study their molecular control. Th
e chosen model is the teleost elasmoid scale of the cichlid fish Hemichromi
s bimaculatus and of the zebrafish Danio rerio. The scales show several exp
erimental advantages and particularly the faculty of regeneration.
We have undertaken an histological study which suggests interactions betwee
n the healing epidermis and the subepidermal mesenchyme during all steps of
the regeneration process and an inductive role of the epidermis during ini
tiation of this phenomenon. The spatio-temporal expression of die genes msx
B, msxC, msxD, Bmp4, shh and ptcl suggest that they could have a role in th
e epidermal and mesenchymal cells profileration and differentiation and in
the formation of scale pattern.