Figure 2
The putative stem cells were located in the external basal cell layer. (A) Tamoxifen-labeled Rosa26CreERT2/rbw mice were administered BrdU and EdU 4 d and 4 h, respectively, before euthanasia. The mice were euthanized 168 d after tamoxifen labeling. (B) Fluorescent image of the transverse sections of the JE in Rosa26CreERT2/rbw mice 168 d after tamoxifen labeling before BrdU/EdU immunostaining (upper row). Immunofluorescence of BrdU and EdU in the same transverse section (lower left). Merged image of lineage tracing and BrdU/EdU-double staining of the same section (lower right). The enlarged image is presented in the right panel (lower right end). Arrowheads indicate the BrdU label-retaining cells observed on the coronal side. The arrow indicates the BrdU/EdU-double labeled cells in the JE. (C) Quantification for the percentage of BrdU, EdU, BrdU/EdU-labeled cells among 1000 cells in JE regions (n = 12 mice, 6 males and 6 females). (D, E) Immunofluorescence of Pan-CK and ki67. The upper first molars of the WT mice were analyzed horizontally. (D) Histological images of the transverse sections. The upper white line sliced the coronal side horizontally, and the lower white line sliced the basal layer horizontally. (E) Hematoxylin and eosin (H&E) stained and Pan-CK + ki67 immunofluorescence images of the horizontal sections of the WT mice. The left panel is the coronal side, and the right panel is the basal layer. The dotted lines indicate the region of the JE (n = 3, 2 males and 1 females). The scale bars represent 20 μm. (F) Fluorescence image of the transverse sections of the JE in Rosa26CreERT2/rbw mice 168 d after labeling with tamoxifen. (G) Immunofluorescence of beta-catenin in the same transverse section as (F). The enlarged image is in the right panel. The arrow indicates the nuclear colocalization of beta-catenin in the JE (n = 3, 2 males and 1 females). The white dotted lines indicate the region of the JE occupied by single-color clones.
