Fig. 5

Immunohistological and cell count results of WT and Pou4f3DTR/+ mice at day 26-28 after cell transplantation. A Schematic of the protocol of cell transplantation. B Immunohistochemistry results at days 26–28 after cell transplantation. Green indicates Cell-EGFP, white indicates Myo7a or Sox2, red indicates Phalloidin or Myo7a, yellow indicates neurofilament-200 kDa, and blue indicates DAPI staining. The organ of Corti of WT mouse is intact but no GFP-positive cells were found. There is neither hair cell nor transplanted human cell in the organ of Corti of non-transplanted side of Pou4f3DTR/+ mouse. There are some GFP+ cells in the transplanted side of Pou4f3DTR/+ mouse, and some of them are positive for Sox2, Myo7a, and NF. White arrow (h) shows the neurofilament (NF) toward the engrafted cells. Scale bars represent 50 μm for c, h, and i, 10 μm for u. C The graph shows numbers of engrafted cells in the organ of Corti of the WT and Pou4f3DTR/+ mouse cochleae at day 28 after transplantation. n = 3. D Schematic of the differentiation of the transplanted human cells in vivo. OHCs, outer hair cells; IHCs, inner hair cells; OC, organ of Corti; WT, wild type; DTR, diphtheria toxin receptor