The Immunohistochemical Patterns of Calcification-related Molecules in the Epidermis and Dermis of the Zebrafish (Danio rerio)

BACKGROUND The scales of bony fish represent a significant reservoir of calcium and calcification of the elasmoid scale is known to be associated with deposition of mineral crystals from the epidermis to dermis. However, little is known about the exact mechanisms of calcium deposition, mobilization and regeneration occurring in the zebrafish skin. OBJECTIVE The purpose of this study was to investigate the expression of calcification-related molecular mediators in both the epidermis and dermis of the zebrafish (Danio rerio), using immunohistochemical study. METHODS We examined the skin of zebrafish in four populations of different ages (i.e. 20 days post-fertilization (dpf), 35 dpf, 50 dpf, and the adult zebrafish), using several immunohistochemical markers, including bone morphogenetic protein 4 (BMP-4), β-catenin, osteocalcin, osteopontin and osteonectin. RESULTS BMP-4, osteopontin and osteonectin were moderately expressed in the epidermis of zebrafish after 35 dpf. Also, some of the cells in the upper dermis showed strong positivity for BMP-4, osteocalcin, osteopontin and osteonetin. CONCLUSION Our results suggest that BMP-4, osteocalcin, osteopontin and osteonectin may play a role in the process of calcification of the elasmoid scale.