STOCK Lmnb1^tm1.1Sgy/J

Stock number: 032558
Product name: Lmnb1fl, Lmnb1 flox
Research areas: Cell Biology Research, Research Tools

Description

These floxed mutant mice possess loxP sites flanking exon 2 of the Lmnb1 gene. This strain may be useful for generating conditional mutations in applications related to cellular proliferation and differentiation.

Detailed description

The targeted Lmnb1 gene encodes a B-type lamin protein that comprises part of the nuclear lamina. Mutations in this gene have been associated with adult-onset, autosomal dominant leukodystrophy. A paralog of this gene is Lmnb2.

These mice possess loxP sites on either side of exon 2 of the targeted gene. Mice that are homozygous for this allele are viable and fertile. When these mutant mice are bred to mice that express Cre recombinase, resulting offspring will have exon 2 deleted in the cre-expressing tissues. Removal of the floxed sequence creates a null allele.

When bred to a strain with Cre recombinase expression in skin keratinocytes (cre under the control of the human keratin 14 gene promoter) and a floxed Lmnb2 strain (Stock No. 032559), this mutant mouse strain may be useful in studies of skin epidermis and hair development.

Of note, a floxed Lmnb2 strain is also available (Stock No. 032559).

Development

A targeting vector containing an FRT site flanked βgeo cassette with an upstream loxP site was utilized in the construction of this mutant. This selection cassette was inserted into intron 1 of the targeted Lmnb1 gene, and a second loxP site was inserted downstream of exon 2 (in intron 2). This construct was electroporated into unspecified 129P2/OlaHsd derived embryonic stem (ES) cells which were transiently transfected with a Flp recombinase plasmid to remove the selection cassette. ES cells that had successfully undergone Flp recombination and no longer retained the cassette but did retain the loxP-flanked exon 2 were injected in blastocysts. The resulting chimeric animals were crossed to C57BL/6 mice. Heterozygotes were intercrossed to generate homozygotes. The donating investigator reports that although these mice harbor no additional mutant loci, they may contain incidental genetic background contributions as a result of past matings with other mutant mouse strains. The mice were backcrossed to C57BL/6J for 2 or 3 generations.

During backcrossing, the Y chromosome may not have been fixed to the C57BL/6J genetic background. Upon arrival, sperm was cryopreserved. To establish our live colony, an aliquot of frozen sperm was used to fertilize C57BL/6J oocytes (Stock No. 000664).

Allele

Symbol: Lmnb1^tm1.1Sgy
Name: targeted mutation 1.1, Stephen G Young
MGI accession ID: MGI:5285669
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Synonyms: Lmnb1^fl
Marker symbol: Lmnb1
Marker name: lamin B1
Marker synonyms: ADLD; LMN; LMN2; LMNB; MCPH26
Chromosome: 18
Strain of origin: 129P2/OlaHsd
Molecular note: An FRT-flanked beta-geo cassette with a 5' loxP site was inserted upstream of exon 2. An additional loxP site was inserted downstream of exon 2.