Altered Differentiation of HCs to “PreHC-Like” Cells

<div><p>Analyses of the proximal tibial growth plate of 10-day-old mice.</p> <p>(A–D and F) In situ hybridization using specific markers for resting, proliferating chondrocytes, and preHCs <i>(Col2a1)</i> (A), preHCs <i>(Ppr)</i> (B), preHCs and HCs <i>(Ihh)</i> (C), proliferating chondrocytes <i>(Ptc)</i> (D), and terminal HCs <i>(Opn)</i> (F). The chondro-osseous junction is depicted by a yellow line).</p> <p>(E) To show that altered differentiation took place after the initiation of hypertrophy, X-gal staining was performed on 10-d-old <i>Col10a1-Cre</i>/ROSA26 Cre reporter (R26R) mice with or without the <i>13del</i> transgene. Positive staining appears as pink under dark field. The inset in the 13del panel shows co-localized X-gal staining (pink) and <i>Ppr</i> in situ hybridization signal (white dots) in mid-lower HZ of the triple mutant.</p> <p>(G) In situ hybridization for <i>Opn</i> and <i>Ppr</i> in consecutive sections. In some HCs of 13del mice, <i>Opn</i> and <i>Ppr</i> are co-expressed (yellow-circled cells). In wt mice, the expression profiles of <i>Opn</i> and <i>Ppr</i> are mutually exclusive (see red- and green-circled cells). Bar indicates 100 μm.</p>