These floxed mutant mice possess loxP sites flanking exon 1 of the Brsk2 gene. This strain may be useful for generating conditional mutations in applications related to the study of axon differentiation.
Joshua R Sanes, Harvard University
The protein encoded by Brsk2 is a serine/threonine-protein kinase that is involved in neuronal polarization, axon specification, axon branching, and presynaptic differentiation in diverse neuronal populations. These mice possess loxP sites on either side of exon 1 of the targeted gene. Mice that are homozygous for the targeted mutation are viable and fertile, with no overt phenotype. When these mutant mice are bred to mice that express Cre recombinase, resulting offspring will have exon 1 deleted in the cre-expressing tissues.
When crossed to Brsk1 knock out mice (Stock No. 023198), and mice expressing Cre recombinase in neurons, the resulting double null homozygotes die shortly after birth due to respiratory failure.
A targeting vector containing a FRT site flanked PGK-Neo selection cassette with a downstream loxP site was utilized in the construction of this mutant. This selection cassette was inserted downstream of exon 1 of the targeted gene, and another loxP site was inserted upstream of exon 1. This construct was electroporated into 129 derived R1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. The resulting chimeric animals were crossed to mice (on an unspecified genetic background) expressing Flpe recombinase under the control of the actin beta promoter to remove the selection cassette. Mice that retained the loxP site flanked exon 1 were then bred to C57BL/6 and CD-1 mice to remove the Flpe recombinase allele.
Upon arrival at The Jackson Laboratory, the mice were crossed to C57BL/6J (Stock No. 000664) at least once to establish the colony.
|Allele Name||targeted mutation 2.1, Joshua R Sanes|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Brsk2, BR serine/threonine kinase 2|
|Strain of Origin||(129X1/SvJ x 129S1/Sv)F1-Kitl+|
|Molecular Note||A loxP site was inserted upstream of exon 1. An FRT-flanked neomycin resistance cassette with a 5' loxP site. Flp-mediated recombination removed the neomycin resistance cassette and left exon 1 floxed.|
When maintaining a live colony, these mice can be bred as homozygotes.
When using the STOCK Brsk2tm2.1Jrs/J mouse strain in a publication, please cite the originating article(s) and include JAX stock #023199 in your Materials and Methods section.