Generation and analyses of <i>Stac3</i> mutant mice.

<p><b>A</b>, Schematic representation of the targeted <i>Stac3</i> allele. The wild-type (WT) <i>Stac3</i> allele has 12 exons, with exon 3 containing the translation start codon. The targeted allele is inserted with a trapping cassette between exons 1 and 2, and this insertion is expected to disrupt the generation of normal <i>Stac3</i> mRNA. Arrows indicate locations of PCR primers for genotyping. <b>B</b>, Genotypes and life of newborn offspring from intercrossing mice heterozygous for the targeted <i>Stac3</i> allele. “+/+”, “+/−”, and “−/−” indicate wild-type mice, and mice heterozygous and homozygous for the targeted <i>Stac3</i> allele, respectively. A total of 10 litters were included in this analysis. C, Images of a <i>Stac3</i> homozygous mutant mouse and a wild-type littermate. Note the curved body shape and dropping forelimbs in the mutant. <b>D,</b> Genotyping by PCR. See panel A for the locations of two pairs of primers. <b>E</b>, Validation of diminished expression of <i>Stac3</i> mRNA in <i>Stac3</i>^−/− mice by standard RT-PCR. Shown is a representative image. <b>F</b>, Real-time RT-PCR validation of diminished expression of <i>Stac3</i> mRNA in <i>Stac3</i>^−/− mice. Data are expressed as mean ± SEM (n = 4). ** <i>P</i><0.01 <i>vs.</i> “+/+”. <b>G</b>, LacZ staining of E13 wild-type and <i>Stac3</i>^+/− embryos. Shown are representative images. The image on the right highlights the stained somites in an E13 <i>Stac3</i>^+/− embryo.