Table 1. Biomechanical and DXA data from tibia of female and male F2 progeny generated from GK and F344 in two reciprocal crosses.
| Sex Effects | Reciprocal Cross Effects | ||||||||
| Irrespective of cross | Females | Males | |||||||
| Females (n = 98) | Males (n = 108) | % Difference (p) | Cross 1 (n = 48) | Cross 2 (n = 50) | % Difference (p) | Cross 1 (n = 66) | Cross 2 (n = 42) | % Difference (p) | |
| General Characteristics | |||||||||
| Body weight (g) | 248±27 | 426±44 | −42 (<10−4) | 247±25 | 248±28 | −0.4 (NS) | 423±44 | 423±45 | −0.05 (NS) |
| Body length (cm) | 21.3±0.7 | 24.9±0.8 | −14 (NS) | 21.3±0.7 | 21.2±0.8 | 0.5 (NS) | 24.9±0.8 | 24.9±0.7 | ∼0 (NS) |
| Tibia length (mm) | 38.9±1.3 | 43.8±1.3 | −11 (<10−4) | 39.1±1.2 | 38.7±1.3 | 1.0 (NS) | 43.9±1.3 | 43.6±1.2 | 0.7 (NS) |
| 3- Point Bending Test | |||||||||
| Ultimate force (N) | 73.4±10.0 | 118±15.3 | −38(<10−4) | 73.4±9.4 | 73.3±10.6 | 0.1 (NS) | 118±15.3 | 118±15.5 | ∼0 (NS) |
| Work to failure (mJ) | 42.8±12.0 | 73.6±27.3 | −42(<10−4) | 44.3±13.6 | 41.4±10.3 | 7.0 (NS) | 72.6±26.7 | 75.1±28.4 | −3.3 (NS) |
| Stiffness (N/mm) | 205±35.6 | 340±65.8 | −40(<10−4) | 207±35.4 | 204±36.0 | 1.5 (NS) | 334±56.6 | 348±78.3 | −4.0 (NS) |
| DXA | |||||||||
| aBMD (g/cm2) | 0.16±0.01 | 0.18±0.01 | −11 (<10−4) | 0.16±0.01 | 0.16±0.01 | ∼0 (NS) | 0.18±0.008 | 0.18±0.009 | ∼0 (NS) |
| BMC (g) | 0.31±0.04 | 0.44±0.05 | −30(<10−4) | 0.31±0.03 | 0.30±0.04 | 3.3 (NS) | 0.44±0.05 | 0.44±0.05 | ∼0 (NS) |
| Projected area (cm2) | 1.92±0.14 | 2.46±0.17 | −22(<10−4) | 1.94±0.13 | 1.90±0.15 | 2.1 (NS) | 2.46±0.18 | 2.47±0.16 | −0.4 (NS) |
Phenotypes are uncorrected and presented as mean ± sd. Cross 1 originate from grand-maternal GK- and cross 2 from grand-maternal F344 rats.
Percentage difference (female compared to male or cross 1 compared to cross 2) is indicated, and nominal p-values determined by ANOVA are given when p<0.05.