[Man-nude mouse tissue chimera: characterization of cell population by in situ hybridization].

In situ hybridization with biotinated probes to total genomic DNAs as well as to the sequences ALu was performed on 13 cutaneous and 19 tumoral human grafts into nude mice. The dermis of cutaneous grafts is progressively overgrown by murine fibroblasts. Primary revascularization took place by development of anastomoses between the human and murine capillary beds. Well-differentiated human neurilemnal sheaths persisted in the grafts until the 6th month. Murine mononuclear cells, resembling Langerhans cells, penetrated the human epidermis. The cells of the fibrous capsules that enclosed the tumors were of mouse origin. Finally, transplantation of human tumors to mice resulted in the replacement of the endothelial and fibroblastic stromal human components by their murine counterparts.