Genetic and morphometric characterization of <i>C/X</i> mice.

<p><i>(A)</i> RT-PCR on cDNA derived from femoral epiphyseal cartilage from wildtype (<i>Wt</i>) and <i>C/X</i> to detect the full-length form of <i>Xbp1</i> (<i>Xbp1</i>_<i>FL</i>) or the inactive form of <i>Xbp1</i>, lacking exon 2 (<i>Xbp1</i>_<i>ΔEx2</i>), and sequencing of cDNA from <i>C/X</i> femoral head cartilage to assay for the deletion of <i>Xbp1</i> exon 2. <i>(B)</i> PCR for residual <i>loxP</i> site downstream of the p.Asn617Lys <i>Col10a1</i> coding sequence using genomic DNA derived from <i>Wt</i> and <i>C/X</i>. <i>(C)</i> Alizarin red S/Alcian blue staining of skeletal preparations from newborn, 1 week, and 2 week wildtype (<i>Wt</i>), <i>Xbp1</i>^{<i>CartΔEx2</i>}, <i>ColX</i>^<i>N617K</i> and <i>C/X</i> mice. <i>(D-F)</i> Quantification of <i>(D)</i> femoral and <i>(E)</i> tibial length, and <i>(F)</i> intercanthal distance (ICD) from legs from 2 week <i>Wt</i> and mutant mice–<i>Wt</i>, N = 8; <i>Xbp1</i>^{<i>CartΔEx2</i>}, N = 8, <i>ColX</i>^<i>N617K</i>, N = 6; <i>C/X</i>, N = 8; statistical analysis performed using Student’s <i>t</i> test.</p>