Figure 1. Expression of FGFRs (FGFR1, FGFR2, FGFR3, and FGFR4) and αKlotho in normal and genetically engineered parathyroid glands.

A specific gene or genes were conditionally manipulated in the parathyroid glands by mating Fgfr1–3^flox/flox, αKlotho^flox/flox, or Fgfr1–4^flox/flox mice with PTH-Cre mice (cKO) or without mating (non-cKO). The mice were treated with heminephrectomy plus a high-phosphate diet (CKD) or not treated (non-CKD) using the protocol described in the Methods section. Paraffin-embedded thyro-parathyroid glands were sectioned and immunostained (red) using an indirect immunofluorescence technique as described in the Methods section. Nuclei were stained with DAPI (blue). Scale bars: 10 μm.