Disrupted development of the sternum in <i>Spag17</i>^<i>-/-</i> mice.

<p>(A) Schematic representation of normal sternal bones (M, manubrium; S1 to S4, sternebrae 1 to 4; X, xiphoid). (B,C and D) Analysis of the sternum by micro-CT scanning shows fused sternebrae in the mutant mice. Pictures are representative images from respective supporting videos. (Fig 3B is representative of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0125936#pone.0125936.s005" target="_blank">S1 Video</a>; Fig 3C is representative of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0125936#pone.0125936.s006" target="_blank">S2 Video</a>; and Fig 3D is representative of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0125936#pone.0125936.s007" target="_blank">S3 Video</a>.) (E and G) Alcian blue/ Alizarin red staining. Failure of ribs 4, 5 and 6 to complete their attachment to the sternum and promote sternebrae separation is apparent in the stained preparations in the <i>Spag17</i>^{<b><i>-/-</i></b>} mice (arrows). (F and H) Representative H&E staining shows the presence of normal cartilage development that prevents fusion of the vertebrae in wild type animals. (+/+), wild-type; (-/-), <i>Spag17</i>-mutant mice. * Fused sternebrae.