Skip to main content
. 2015 Dec;94(12):1668–1675. doi: 10.1177/0022034515598135

Figure 1.

Figure 1.

There are few TUNEL (apoptotic)–positive hypertrophic chondrocytes (HCs) but abundant Bcl-2 (B-cell lymphoma 2, a critical antiapoptotic factor)–positive HCs, which maintain a high activity of alkaline phosphatase (ALP; an early osteoblast marker) with some cell division. Anti-BrdU immunostaining images display a higher number of proliferating cells at postnatal day 1 (P01, blue arrows) (a) than those at P10 (b; blue arrows), including some BrdU-positive dividing cells in HC zone. (c) TUNEL immunostaining assay showed more positively stained HCs and bone cells (red arrowheads) at postnatal day 1 (P01; upper panel) than at P10 (lower panel). (d) Anti-Bcl-2 immunostained images showed that the Bcl-2-positive mature chondrocytes (brown, red arrows) were found in the entire HC zone at both P01 (left panel) and P10 (right panel). (e) ALP activity was detected in most chondrocytes at P01 (left panel, red arrows) and remained active mainly in mature chondrocytes at P10 (right panel). In addition, ALP was detected in all progenitor cells in perichondrium and periosteum at both developmental stages.