Samples from the same age-matched cohorts were used for imaging, biomechanical and histological tests. Mice were culled by cervical dislocation and stored frozen at − 20 °C for biomechanical studies. For histological studies, mice were deeply anaesthetized with pentobarbitone (50 mg/kg, intraperitoneally) IWR1 and transcardially perfused with 4% paraformaldehyde (in 0.1 M phosphate buffer, pH 7.4). To establish MeCP2 expression in bone tissues, we used a MeCP2-GFP

reporter line as described previously [31] and with sections imaged by laser scanning confocal microscopy (Bio-Rad Radiance 2100, UK). Both right and left femurs and tibias along with the 5th lumbar vertebrae from each mouse were carefully dissected out. Femur and tibia whole bone wet weight measurements were taken using an analytical balance (APX60, Denver Instruments, UK). The femur and tibia were imaged using a WolfVision Visualizer VZ9.4F (WolfVision Ltd., Maidenhead, UK) and gross

lengths were measured using Axiovision 4.8 Software (Carl Zeiss Ltd., Cambridge, UK). Femoral length measurements Palbociclib molecular weight were taken from the proximal aspect of the greater trochanter to the distal end of bones, along the line of the shaft. Tibial length measurement was taken from the proximal aspect of the head of the tibia to the distal most aspect of the medial malleolus. Samples were then stored at − 20 °C in 0.1 M phosphate buffer prior to further testing. Right femurs were used for mechanical testing (the proximal part for the femoral neck test, the midshaft for microindentation) and left femurs were used for the bone histology (the proximal femur for sirius red and TRAP staining, the distal femur for scanning electron microscopy). Right tibias were used for μCT and three-point bending tests. The 5th lumbar vertebrae were used for bone mineral density and trabecular bone structure measures. The right humeri were used for analysis of the bone mineral structure using Small Angle X-ray Scattering (SAXS). Tibias and lumbar 5 vertebras were

scanned with a SKYSCAN® 1172/A μCT Scanner (Bruker, Belgium). Images were reconstructed and analysed using the NRecon 1.6.6.0 and CT-Analyser 1.8.1.3 software (Bruker, Belgium). For the tibia, 34 μm resolution was used and the X-ray tube was operated at 54 kV and 185 μA. Etomidate Bone samples were scanned in physiological 0.9% NaCl solution. For cortical bone parameter analyses, tibial 2 mm midshaft regions of interest (ROI) were selected, starting from the anatomical point of the tibiofibular junction in each specimen. A lower grey threshold value of 113 and upper grey threshold value of 255 was used as thresholding values in each cortical bone sample. Individual two dimensional object analyses were performed on six sections per specimen within each comparison genotype group to calculate the inner and outer perimeters of bone.