These Dbx1flox mutant mice possess loxP sites flanking exons 2 through 4 of the Dbx1 gene. This strain may be useful for generating conditional mutations in applications related to CNS neuronal progenitor subpopulation fate mapping.
Joshua Corbin, Children's National Medical Center
The developing brain homeobox 1 transcription factor, encoded by the Dbx1 gene, plays a role in the developing central nervous system and is important for specification of neuronal subgroups.
These mice possess loxP sites flanking exons 2, 3, and 4 of the targeted gene. The DNA-binding homeodomain is encoded by exons 3 and 4. 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 exons 2, 3, and 4 deleted in the cre-expressing tissues. The allele carried by these mice contains NEO.
When bred to a strain with Cre recombinase expression in brain progenitor cells (see Stock No. 008661 for example), this mutant mouse strain may be useful in studies of interneuronal patterning development in the hypothalamus.
A targeting vector containing a FRT site flanked NEO cassette was utilized in the construction of this mutant. A loxP site and this selection cassette was inserted downstream of exon 4 of the targeted gene, and another loxP site was inserted upstream of exon 2. This construct was electroporated into (129X1/SvJ x 129S1/Sv)F1-Kitl+ derived R1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts. The allele carried by these mice contains a NEO cassette.
The mice were bred to another mutant strain on a congenic C57BL/6 background and then backcrossed to C57BL/6 for approximately 20 generations by the donating lab (see SNP note below).
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).
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. Sixteen of the 27 markers throughout the genome were segregating, suggesting an incomplete backcross. Three markers were segregating from an unknown source. Also 1 of 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 C57BL/6J ; C57BL/6N genetic background.
|Allele Name||targeted mutation 2, Joshua Corbin|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Dbx1, developing brain homeobox 1|
|Strain of Origin||(129X1/SvJ x 129S1/Sv)F1-Kitl+|
|Molecular Note||The targeting vector contains a loxP site upstream of exon 2 and a loxP site downstream of exon 4 followed by an FRT-flanked neomycin cassette.|
When maintaining a live colony, these mice can be bred as homozygotes.
When using the Dbx1 flox mouse strain in a publication, please cite the originating article(s) and include JAX stock #028223 in your Materials and Methods section.