These mice possess loxP sites on either side of exon 7 of the targeted gene. Mice that are homozygous for this allele are viable, fertile, normal in size and do not display any gross physical or behavioral abnormalities.
When these "floxed" mice are bred to mice that express Cre recombinase, resulting offspring can have one of three resulting genotypes (only exon 7 deleted, only the neo selection cassette deleted, or both exon 7 and the neo selection cassette deleted) in the cre-expressing tissue(s). These PS1-floxed mice may be useful in generating conditional knockouts of Presenilin 1 for studying Alzheimer's Disease.
For example, when crossed to a strain expressing Cre recombinase in postnatal neurons (see Stock No. 006143), this mutant mouse strain may be useful in studies of amyloid plaque formation.
In an attempt to offer alleles on well-characterized or multiple genetic backgrounds, alleles are frequently moved to a genetic background different from that on which an allele was first characterized. It should be noted that the phenotype could vary from that originally described. We will modify the strain description if necessary as published results become available.
A loxP site flanked targeting vector containing a neomycin resistance gene was utilized in the construction of this mutant. This selection cassette was inserted downstream of exon 7 of the targeted gene, and another loxP site was inserted upstream of exon 7. This construct was electroporated into 129P2/OlaHsd derived E14 embryonic stem (ES). Homozygotes on a mixed B6;129P2 genetic background were sent to The Jackson Laboratory (as Stock No. 007605). Upon arrival, some mice were backcrossed to C57BL/6J inbred mice (Stock No. 000664) for at least 5 generations to generate this congenic strain (Stock No. 007685) (see note below).
NOTE: For the parental strain (Stock No. 007605), a 27 SNP (single nucleotide polymorphism) panel analysis performed by The Jackson Laboratory revealed a single loci that typed as homozygous for 129/P strain type (Chromosome 12 approximately 9.8 cM) and three additional loci that were segregating for either C57BL/6J or 129/P strain type (Chromosome 1 approximately 52.0 cM, Chromosome 4 approximately 10.9 cM, and Chromosome 8 approximately 4.4 cM). These loci are to be monitored and attempted to be changed to C57BL/6J-like during the backcrossing protocol to generate the congenic strain (Stock No. 007685). Because the targeted mutation also resides on chromosome 12, that loci may remain as 129/P strain type even after backcrossing (August 2008).
|Allele Name||targeted mutation 1, Fred Van Leuven|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Psen1, presenilin 1|
|Strain of Origin||129P2/OlaHsd|
|Molecular Note||Exon 7 was flanked by a single loxP site in intron 6 and floxed neo cassette in intron 7.|
|Mutations Made By|| |
Fred Van Leuven, Experimental Genetics Group - KULeuven
Mutant mice were bred to C57BL/6J inbred mice (Stock No. 000664) for many generations to establish this congenic strain. When maintaining the live congenic colony, heterozygous or homozygous mice may be bred together.
When using the B6.129P2-Psen1tm1Vln/J mouse strain in a publication, please cite the originating article(s) and include JAX stock #007685 in your Materials and Methods section.