Figure 3

Histological examination of osteogenic cell lineages in sFRP4 ^LacZ/LacZ mice.

Femurs from sFRP4 ^LacZ/+ and sFRP4 ^LacZ/LacZ mice at 5 weeks of age were processed for histological analyses. (a–e) Representative images of femur stained with hematoxylin and eosin. Cuboidal cells in the trabecular bone surface are more numerous in sFRP4 ^LacZ/LacZ mice compared with those in sFRP4 ^LacZ/+ mice (a,b; red arrows). Distinct flattened cells in the periosteum (e; red arrows) are absent in sFRP4 ^LacZ/LacZ mice (f). (g–j) Axin2 protein expression at the trabecula and the periosteum. (i,j) Axin2 protein expression is strikingly decreased in the sFRP4 ^LacZ/LacZ periosteum compared with that in sFRP4 ^LacZ/+ mice (red arrows, signal positive cells ratio; control 12% and KO 32%). (g,h) In contrast, Axin2 protein expression in the sFRP4 ^LacZ/LacZ trabecular region is higher than that in sFRP4 ^LacZ/+ (positive stained cells ratio; control 24% and KO 48%). Bidirectional arrows denote periosteal width (c,d,i,j). Magnifications of the red boxed regions (c,d) are shown in (e,f). Bars 50 μm (a–d), 25 μm (e,f), 100 μm (g–j).