Localization of fibronectin and beta1 integrin in cultured skin fragments of larvae of salamandra salamandra salamandra.

As part of a study on the pigmentary system of Salamandra salamandra salamandra we cultured skin fragments from 7-10 day old larvae in order to examine the expression of molecules implicated in both cellular adhesion and migration and in regulating the relationships among cells. Skin fragments were cultured for 10-15 days on glass coverslips in Petri dishes. Fragments attached to the coverslips within 24h and fibroblastic and epithelial cells gradually migrated from the fragments. Keratinocytes formed a monolayer above the fibrobasts. Whitin 36-48 h Leydig cells, melanophores and xantophores were observed beneath the keratinocytes. In vitro melanophores and xantophores have two shapes: dendritic when mobile and round when stationary. Immunofluorescence method was applied to the cultures to localize fibronectin and beta1 integrin. Many keratinocytes and fibroblasts showed variably strong immunofluorescence against anti-fibronectin or anti-beta1 integrin. The staining reaction for beta1 integrin was diffuse on the surface of the round melanophores, whereas it did not seem to be expressed on the dendritic chromatophores.