Table 2.

Femoral microarchitecture assessed by μCT of 1, 3 and 6 month old male and female Grem1 null mice and wild type littermate controls.

Males	1 Month		3 Month		6 Month
	Wild Type	Grem1 null	Wild Type	Grem1 null	Wild Type	Grem1 null
Bone Volume/Tissue Volume (%)	6.1 ± 0.4	2.9 ± 0.4*	8.4 ± 1.4	8.5 ± 1.6	4.7 ± 0.9	2.7 ± 0.3*
Trabecular Separation (μm)	224 ± 11	343 ± 22*	228 ± 20	221 ± 11	277 ± 12	423 ± 57*
Trabecular Number (1/mm)	4.6 ± 0.2	3.0 ± 0.2*	4.6 ± 0.2	4.5 ± 0.2	3.6 ± 0.1	2.6 ± 0.3*
Trabecular Thickness (μm)	26.9 ± 0.7	25.6 ± 0.5	34.2 ± 1.4	38.8 ± 2.5	35.8 ± 1.4	45.4 ± 3.4*
Connectivity Density (1/mm3)	211 ± 21	44 ± 11*	226 ± 51	144 ± 37	67 ± 16	2.6 ± 7*
Structure Model Index	2.7 ± 0.05	2.9 ± 0.05*	2.9 ± 0.2	2.5 ± 0.2	2.8 ± 0.2	2.9 ± 0.3
Cortical Thickness (μm)	112 ± 1	97 ± 5*	179 ± 7	186 ± 7	171 ± 4	185 ± 5
Females	1 Month		3 Month		6 Month
	Wild Type	Grem1 null	Wild Type	Grem1 null	Wild Type	Grem1 null
Bone Volume/Tissue Volume (%)	5.8 ± 0.7	3.6 ± 0.7+	5.0 ± 0.8	5.5 ± 0.9	3.8 ± 0.6	3.5 ± 0.8
Trabecular Separation (μm)	224 ± 16	305 ± 33+	260 ± 12	292 ± 26	351 ± 19	394 ± 15
Trabecular Number (1/mm)	4.6 ± 0.3	3.5 ± 0.4*	3.9 ± 0.2	3.5 ± 0.3	2.9 ± 0.1	2.6 ± 0.1
Trabecular Thickness (μm)	26.3 ± 0.7	26.5 ± 0.9	33.1 ± 1.7	42.2 ± 1.8	39.1 ± 3.5	50.0 ± 5.3
Connectivity Density (1/mm3)	222 ± 40	78 ± 26*	109 ± 29	66 ± 19	51 ± 8	37 ± 11
Structure Model Index	2.7 ± 0.1	2.9 ± 0.1	2.5 ± 0.2	2.7 ± 0.2	2.9 ± 0.1	3.2 ± 0.3
Cortical Thickness (μm)	119 ± 6	94 ± 6*	177 ± 4	184 ± 9	196 ±3	191 ± 5

Bone μCT was performed on femurs from 1, 3 and 6 month old male and female Grem1 null and wild type littermate controls. Voxel size used for analysis was 6 μm³. Values are means ± SEM; n = 5 to 6.

^*Significantly different from controls, p < 0.05 by unpaired t test.

⁺p <0.057