The q-range measured was 0.01–0.30 Å− 1. Measurements were conducted with the samples mounted on an x–y motorised stage and a step size of 100 μm with an exposure time of 5 s at each point was used to scan the cross-section of the bone [35]. The detector used was a PILATUS 1 M (Dectris Ltd.). The mineral plate thickness, predominant orientation and degree of orientation of the mineral crystals were calculated for each scattering image as described earlier [35], [36] and [37]. Only scattering images where the signal level indicated the presence of cortical bone were analysed. Unless states otherwise, all data is given as mean ± standard deviation (S.D.). For statistical
analysis of imaging, biomechanical and histological data, one way ANOVA with Tukey’s post hoc test were conducted using Prism 5.0 (Graphpad, USA) with alpha being 0.05. MeCP2 protein is Akt molecular weight particularly abundant in post-mitotic cells of the brain, but is also widely expressed throughout the body [7], [9] and [38]. In order to confirm
that bone cells express MeCP2 IWR-1 cell line we used a reporter mouse line in which MeCP2 expresses a C-terminal GFP tag [31]. We observed that all bone cells express nuclear GFP fluorescence in both wild type male (Fig. 2A) and female mice (data not shown). In contrast, GFP fluorescence is absent in hemizygous Mecp2stop/y mice ( Fig. 2B), in which Mecp2 is silenced by a stop cassette, and is observed in ~ 50% of nuclei in heterozygous Mecp2+/stop mice in which one Mecp2 allele is silenced to mimic the mosaic expression pattern seen in human female Rett syndrome [26] and [30]
( Fig. 2C). In order to determine any gross skeletal abnormalities caused find more by MeCP2 deficiency, the tibia and femur of male Mecp2stop/y mice together with wild-type littermates were examined for gross morphometric and weight measures ( Table 1). No difference in whole body weights was observed between genotypes in male mice (Wt = 31.88 ± 3.85 g; Mecp2stop/y = 28.14 ± 4.07 g; Mecp2stop/y, CreER = 27.74 ± 2.68 g; n = 5 per genotype; p < 0.05, ANOVA with Tukey's post hoc test) or in the female comparison genotypes (Wt = 32.72 ± 5.59 g; Mecp2+/stop = 41.70 ± 7.15 g; Mecp2+/stop, CreER = 39.47 ± 9.77 g; n = 5 per genotype; p < 0.05, ANOVA with Tukey's post hoc test). Mecp2stop/y mouse femurs showed a significantly reduced weight in comparison with wild-type (Wt) littermate controls and Mecp2stop/y, CreER (Wt = 51.90 ± 3.77 mg; Mecp2stop/y = 44.80 ± 3.41 mg; Mecp2stop/y, CreER = 51.80 ± 5.87 mg; n = 5 per genotype; p < 0.05, ANOVA with Tukey's post hoc test). A similar trend was observed in Mecp2stop/y mouse tibias, weight measures (Wt = 55.50 ± 2.11 mg; Mecp2stop/y = 49.20 ± 1.21 mg; Mecp2stop/y, CreER = 52.12 ± 2.96 mg; n = 5 per genotype; p < 0.05, ANOVA with Tukey's post hoc test). There was an accompanying reduction in tibial length (p < 0.01), but no significant difference in femoral length between groups (p > 0.05) ( Table 1).