These Nkx6.1flox mutant mice possess loxP sites flanking exon 2 of the NK6 homeobox 1 (Nkx6-1) gene. NKX6.1 is a transcription factor required for the development and maintenance of pancreatic beta cells. Homozygotes are viable and fertile. When bred to mice that express a tissue-specific Cre recombinase, resulting offspring will have exon 2 deleted in cre-expressing tissues of the offspring.
A targeting vector was designed to insert a loxP site upstream of exon 2, and a frt-flanked neomycin resistance (neo) cassette followed by a second loxP site downstream of exon 2 of the NK6 homeobox 1 (Nkx6-1) gene. The construct was electroporated into 129S6/SvEvTac embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts and resulting chimeric males were bred with C57BL/6NCrl females. Offspring were bred with B6.Cg-Tg(ACTFLPe)9205Dym/J
(Stock No. 005703) transgenic mice to delete the neo cassette, and progeny were crossed to remove the Flp-expressing transgene. The donating investigator reported that these mice were bred to C57BL/6NCrl mice for at least 6 generations (see SNP note below). Upon arrival, mice were bred to C57BL/6NJ inbred mice (Stock No. 005304) for at least one generation 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. Seven of the 27 markers throughout the genome were segregating with 129 suggesting an incomplete backcross.
|Allele Name||targeted mutation 1.1, Maike Sander|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Nkx6-1, NK6 homeobox 1|
|Strain of Origin||129S6/SvEvTac|
|Molecular Note||A loxP site was inserted upstream of exon 2. An FRT-flanked neomycin resistance (neo) cassette with a 3' loxP site was inserted downstream of exon 2. Flp-mediated recombination removed the neo cassette and left exon 2 floxed.|
When maintaining a live colony, homozygous mice may be bred together.
When using the Nkx6.1