Homozygotes are viable and fertile. No protein product from the targeted gene is detected in skeletal muscle, cardiac muscle, or intestinal smooth muscle. Other components of the dystrophin-glycoprotein complex (DGC) are maintained in the sarcolemma in the absence of this gene product. The muscle appears to be normal by histological analysis, and sarcolemma integrity is maintained as determined by serum creatine kinase measurements and the absence of Evans blue dye uptake. The muscle also maintains normal force and power generation capacity. These mice do not show any hallmarks of a muscular dystrophy phenotype. This mutant mouse strain represents a model that may be useful in studies of muscle function.
A targeting vector containing a floxed neomycin resistance gene was use to replace exon 2 and the coding sequence of exon 3 which encode three of the four transmembrane domains, the extracellular loop, and the C-terminal intracellular domain. The construct was electroporated into (129X1/SvJ x 129S1/Sv)F1-Kitl+-derived R1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts. The strain has been backcrossed five times to C57BL/6 by the donating laboratory.
|Allele Name||targeted mutation 1, Kevin P Campbell|
|Allele Type||Targeted (Null/Knockout)|
|Gene Symbol and Name||Sspn, sarcospan|
|Strain of Origin||(129X1/SvJ x 129S1/Sv)F1-Kitl+|
|Molecular Note||The gene was disrupted by replacement of exons 2 and 3 with a PGK-neo cassette resulting in deletion of sequences encoding 3 of 4 transmembrane domains, the extracellular loop, and the C-terminal intracellular domain. Absence of gene expression in homozygous animals was demonstrated by Northern blot analysis of skeletal muscle RNA. Western blot analysis of skeletal muscle microsomes, and immunofluorescence analysis of smooth muscle cells from the small intestines further confirmed the absence of encoded protein in homozygous animals.|
|Mutations Made By|| |
Kevin Campbell, University of Iowa
When maintaining a live colony, homozygotes are intercrossed.
When using the Sspn KO mouse strain in a publication, please cite the originating article(s) and include JAX stock #006837 in your Materials and Methods section.