This Lamc2jeb mutant mouse strain may be useful in studies of epidermolysis bullosa and is a model for Non-Herlitz Type Junctional Epidermolysis Bullosa.
Derry Roopenian, The Jackson Laboratory
Mice that are heterozygous for this mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. Northern blot analysis of skin from homozygotes detects the wildtype and a dominant larger sized mutant gene product (mRNA). Homozygotes express a reduced level of gene product (protein), as detected by Western blot analysis of keratinocytes. Mean onset of progressive skin blistering disease in homozygotes on the 129X1 background is age 154 days. Homozygotes exhibit ulcerated lesions and tissue granulation in ear skin, which develops into deformed pinna; ulcerated lesions in the footpads and tail. Thickened epidermis (hyperplasia) and subepidermal separation, with little to no inflammation, occurs in the skin of the footpads and tail. Ultrastructural analysis of skin with electron microscopy reveals that the dermal-epidermal separation occurs at the lamina lucida.
The Lamc2jeb spontaneous mutation arose in the 129X1-Fcgrttm1Dcr/Dcr colony of Dr. Derry Roopenian. The mutation was revealed to be a single retroviral insertion (murine leukemia virus long terminal repeat) in intron 18 of the Lamc2 gene. Heterozygotes were intercrossed to generate homozygotes.
|Allele Name||junctional epidermolysis bullosa|
|Allele Type||Spontaneous (Hypomorph)|
|Gene Symbol and Name||Lamc2, laminin, gamma 2|
|Strain of Origin||129X1/SvJ|
|Molecular Note||Sequencing of mutant genomic DNA revealed the presence of a single murine leukemia virus long terminal repeat (MLV LTR) insertion of 560 bp within the eighteenth intron. Northern blot and RT-PCR analysis detected an aberrant transcript that retains intron 18 and the LTR, and introduces a TAG translational stop codon in intron 18. However, a correctly spliced WT transcript is also produced at low abundance suggesting that this allele acts as a hypomorph. A noncomplementation test with a null allele of this gene further confirmed that the insertion is the cause of the mutant phenotype.|
When maintaining a live colony, these mice can be bred as homozygotes. Mean onset of phenotypic traits in mice homozygous for the mutation on the 129X1 background is age 154 days.
When using the 129X1/SvJ-Lamc2jeb/DcrJ mouse strain in a publication, please cite the originating article(s) and include JAX stock #006859 in your Materials and Methods section.