B6;129P2-Lum^tm1Wwk/J

Stock number: 014558
Research areas: Cell Biology Research, Dermatology Research, Immunology, Inflammation and Autoimmunity Research, Internal/Organ Research, Research Tools, Sensorineural Research

Description

This mutant mouse strain carrying a targeted mutation of Lum, lumican, exhibits delayed wound healing and fragile skin. These mutant mice may be useful in studies of collagen fibrillogenesis and matrix organization, extracellular matrix, corneal inflammatory response, and epithelial wound healing, including neutrophil recruitment and invasion.

Detailed description

Mice that are homozygous for the targeted mutation are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities. Male mice homozygous for this targeted mutation on the C57BL/6 background produce fewer pups than homozygous females when mated to wildtype mice. No gene product (mRNA or protein) is detected by Northern blot, in situ hybridization, and immunohistochemical analysis of eye tissue from homozygotes. Homozygotes exhibit fragile skin, disarranged back skin hair, age related progressive corneal opacity and delayed corneal epithelial wound healing. Although the neutrophil infiltration response to lipopolysaccharide (LPS)-induced corneal keratitis in homozygous mutant mice is diminished when compared to wildtype controls, corneal haze is more pronounced. Keratocan levels in corneas from homozygotes is reduced compared to wildtype controls. Ultrastructural examination of the sclera from homozygotes reveals abnormal scleral morphology with less organized lamellae, collagen fibrils of larger diameter, and disorganized interfibrillar spacing. Sclera from heterozygotes exhibit an intermediate structural phenotype.

Development

A targeting vector containing a PGK-Hprt selection cassette was used to disrupt exon 2. The construct was electroporated into 129P2/OlaHsd derived E14TG2a embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6J blastocysts. The resulting chimeric animals were crossed to C57BL/6J mice. Then donating investigator reports that these mice were backcrossed to C57BL/6 for 10 generations (see SNP note below). Upon arrival at The Jackson Laboratory, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to establish the colony.

A 32 SNP (single nucleotide polymorphism) panel analysis, with 27 markers covering all 19 chromosomes and the X chromosome, as well as 5 markers that distinguish between the C57BL/6J and C57BL/6N substrains, was performed on the rederived living colony at The Jackson Laboratory Repository. Eleven of the 27 markers throughout the genome were found to be segregating. All 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed genetic background.

Allele

Symbol: Lum^tm1Wwk
Name: targeted mutation 1, Winston W Y Kao
MGI accession ID: MGI:2181377
Generation method: Targeted
Attributes: Null/Knockout
Marker symbol: Lum
Marker name: lumican
Chromosome: 10
Strain of origin: 129P2/OlaHsd
Molecular note: The gene was disrupted by replacement of 481 bp of exon 2 with a PGK-hprt cassette (in the opposite orientation) via homologous recombination. Northern blot, in situ hybridization, and immunohistochemistry confirmed the absence of mRNA and protein expression in eyes of homozygous mutant animals.