FIGURE 3. Purkinje cells fuse with BMDCs after bone marrow transplantation.

a, A -gal⁺ Purkinje neuron in the cerebellum of a R26R mouse transplanted with Cre⁺ bone marrow cells. b, A 1.5-m-thick section of the -gal⁺ Purkinje cell soma (blue–green in colour) counter-stained with toluidine blue. This cell displays two nuclei (arrow and arrowhead) with very different morphological characteristics. c, Electron microscopy of the bi-nucleated fused Purkinje cell. Dark concretions in the reticulum and around the nuclear membrane correspond to the X-gal precipitate. One nucleus is wrinkled and invaginated (star), typical of Purkinje cells, whereas the second nucleus (asterisk) has a homogeneous spherical shape, suggesting that the nuclei have different origins. d, Electron microscopy photomicrograph of synaptic contacts (arrowheads) in a -gal⁺ Purkinje cell. Scale bars: a, 40 m; b, 10 m; c, 5 m; d, 1 m.