Fibromatous skin masses in <i>Sml</i> and <i>Oed</i> mice.

<p>(A) An ulcerated pedunculated hairless mass on the front paw (arrow) of 7-month-old <i>Oed</i> male mouse. (B) X-ray of this lesion shows radio-opacities (arrow). (C) A hairless nodule on the tail (arrow) of a 12-month-old <i>Oed</i> male mouse. (D, E and F) A pedunculated mass in a 8-month-old <i>Oed</i> male mouse. (D) This mass has a narrow pedicel (arrow p) and is focally ulcerated (arrow u). (E) Intact hyperkeratotic epithelium (arrow e) bordering a mass of fibromatous connective tissue (arrow f) with an entrapped follicle (arrow ef) and associated sebaceous gland. (F) Focal areas of osseous heteroplasia (arrow o) within the fibromatous mass (arrow f). Scale bars: A,B,C = 0.5 mm; D = 1 mm; E = 100 µm; F = 50 µm.</p

Skin radio-opacities increase with age in <i>Sml</i> and <i>Oed</i> mice and correspond to foci of osseous heteroplasia.

<p>(A) X-ray image of radio-opacities in the skin of a 12-month-old <i>Sml</i> male imaged on a 1×1 cm grid. (B) The number and (C) cumulative area of skin radio-opacities in <i>Sml</i> and <i>Oed</i> male mice at 6 & 9 months of age are not significantly different from +/+ controls, however they are significantly increased in the 12 & 15-month-old cohorts compared to +/+ mice. (D) The number and (E) cumulative area of skin radio-opacities in <i>Sml</i> and <i>Oed</i> females at 6 & 9 months of age are not significantly different from +/+ controls, however they are significantly increased in the 12 & 15-month-old <i>Sml</i> compared to +/+ controls. In the box and whisker plots each box represents the median with 25 and 75% inter-quartile ranges, with whiskers representing the data range (minimum and maximum). The group size <i>n</i> is indicated alongside each histogram bar, whereas the circled numbers are the off-scale maximum values. ns = not significant <i>P</i>>0.05, * <i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001. Kruskall Wallis non-parametric one-way ANOVA tests were performed with Dunn's multiple comparison tests for post hoc testing. † A single male +/+ control with high levels of radio-opacities was an outlier that had a wounded skin. (F). Radio-opacities correspond to foci of osseous heteroplasia (arrow o) with osteoclasts (arrow oc) beneath intact skin. (G) Focus of hematopoietic tissue (arrow h) within an area of osseous heteroplasia, inset is enlarged view (arrow h), the bone surface has an osteoblast layer (arrow ob). Scale bars: F = 100 µm; G = 200 µm.</p

Histological analysis of skin x-ray radio-opacities in <i>Oed</i> and <i>Sml</i> mice.

<p>2×2 Fisher Exact tests were used to compare proportions of <i>Sml</i> or <i>Oed</i> with +/+ control mice bearing each lesion. ns = not significant <i>P</i>>0.05,</p>*<p><i>P</i><0.05,</p>***<p><i>P</i><0.001.</p

Plasma biochemistry phenotypes of male <i>Sml</i> and <i>Oed</i> mice.

<p>(A) Plasma PTH was significantly elevated in <i>Oed</i> mice at 6 & 9 and 12 & 15 months of age compared to +/+ controls. The modest elevation in <i>Sml</i> PTH levels at 6 & 9 months failed to reach significance (<i>P</i> = 0.053) but PTH was significantly elevated at 12 & 15 months compared with respective +/+ controls. Plasma calcium corrected for albumin levels (B) in <i>Oed</i> mice was lower than their respective +/+ controls at 6 & 9 months but not at 12 & 15 months. Calcium in <i>Sml</i> males was not lower than in their respective +/+ controls at 6 & 9 months but was lower than controls at 12 & 15 months. Plasma phosphate levels (C) in <i>Oed</i> mice were higher compared with their respective +/+ controls at 6 & 9 months but not at 12 & 15 months. Plasma phosphate in <i>Sml</i> males was not significantly different from +/+ controls at 6 & 9 months and at 12 & 15 months was lower than +/+ controls. The group size <i>n</i> is indicated alongside each histogram bar, the error bar is ± s.e.m; ns = not significant <i>P</i>>0.05, *<i>P</i><0.05, **<i>P</i><0.01, ***<i>P</i><0.001. 2-tailed t-tests with unequal group variance were performed on the PTH data.</p

Protein coding transcript map of the mouse <i>Gnas</i> cluster (modified from ref [<b>66</b>]).

<p>Features of the maternal and paternal alleles are shown above and below the line. Arrows show direction of transcription. Transcripts arising from the first exons of protein coding transcripts, <i>Nesp</i>, <i>Gnasxl</i>, and <i>Gnas</i> splice onto exon 2 of <i>Gnas</i>. For <i>Gnas</i> the unbroken arrow shows predominant maternal expression and the dotted line indicates limited paternal expression. The asterisk indicates the <i>Oed-Sml</i> mutation in exon 6.</p