Figure 3

Co-localisation of Y FISH and cytokeratin immunosignal in single cells. Female animals engrafted with male bone marrow were sacrificed after three months and cells dissociated from the tracheas were cytospun onto slides and subjected to Y FISH (red) and cytokeratin immunocytochemistry (green). Y positive (donor derived) cells are arrowed and both Y chromosome positive and cytokeratin negative (panels A,G and I) and Y positive, cytokeratin positive cells (panel B,C and E) were observed. Non-arrowed cells in panels A and B are cytokeratin positive but not Y FISH positive and presumably host female derived. Panels C and G show donor cells (arrow) stained for presence of Y chromosome and then the slides were counterstained with H and E (panel D and H respectively). Panels E and I show the donor Y FISH positive cells (arrowed) with panels F and J showing the same cells stained with H and E. The donor cell (arrowed) in panels I and J is cytokeratin negative and has macrophage morphology.