Fig. 1

Identification of the CL-MSCs in the mouse incisor tooth. a Whole view of one P7 mouse lower incisor. Black arrowheads show approx. boundaries of indicated epithelial cells zones: ESCs epithelial stem cells, ETACs epithelial transit amplifying cells, MTACs, mesenchymal transit amplifying cells, and dentin layer. Light blue dotted line indicates epithelial–mesenchymal junction. b Stereo front view of a P7 incisor CL epithelium (left) and arbitrarily colored indexes for the ESCs (purple) and ETACs (green) regions (right). c Immunofluorescence analysis of indicated antigenic markers in P7 incisors. Nuclei were counterstained with DAPI. Light blue dotted line shows epithelial–mesenchymal junction while yellow arrowheads indicate the mesenchymal cells named CL-MSCs. NVB neurovascular bundle region. d, e Gene expression profiling using real time RT-PCR analysis on laser captured MTACs, CL-MSCs, and NVB-MSCs from n = 5 biologically independent animals, using two panels of general MSCs (d) and MTACs (e) markers. Triplicated samples were used for each gene. Error bars represent standard deviation. Statistical analysis was performed with two-way ANOVA followed by Bonferoni correction. No asterisk: p > 0.05; one asterisk: p < 0.05; two asterisks: p < 0.01. f, g Immunofluorescence analysis using indicated markers. In g, squared region in the right panel is enlarged in the left one. Note the overlapped expression of SmarcA2 and Ki67 at the junction of CL-MSCs and MTACs. Light blue dotted line shows epithelial–mesenchymal junction while yellow arrowheads indicate the mesenchymal cells named CL-MSCs. Bars: a: 100 μm; b, c, f, g (left panel): 40 μm; g (right panel): 10 μm