Fgf21loxP mutant mice possess loxP sites flanking exons 1-3 of the fibroblast growth factor 21 (Fgf21) gene. These mice may be useful for studying the role of FGF21 in coordinating metabolic responses to fasting.
David Mangelsdorf, UT Southwestern Medical Center
These Fgf21loxP mice possess loxP sites flanking exons 1-3 of the fibroblast growth factor 21 (Fgf21) gene. FGF21 is an endocrine hormone, expressed in liver and pancreas, which stimulates glucose uptake in adipocytes. FGF21 induction in liver by peroxisome proliferator-activated receptor a (PPARa) during fasting induces fatty acid oxidation ketogenesis in liver. Homozygotes are viable and fertile. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have exons 1-3 deleted in the cre-expressing tissues.
For example, when bred to B6.129S4-Meox2tm1(cre)Sor/J mice (Stock No. 003755) expressing germ line Cre-recombinase, livers from resulting offspring have decreased beta-oxidation, ketogenesis, and gluconeogenesis under fasted conditions.
Of note, the knock-out version of this allele is available as Stock No. 033846.
A targeting vector was designed to insert a loxP site upstream of exon 1, followed by a second loxP site and a frt-flanked neomycin resistance (neo) cassette downstream of exon 3 of the fibroblast growth factor 21 (Fgf21) gene. The construct was electroporated into 129S6/SvEvTac embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6J blastocysts and resulting chimeric males were bred to C57BL/6J females. Offspring were bred with B6;SJL-Tg(ACTFLPe)9205Dym/J transgenic mice (Stock No. 003800) to delete the neo cassette, and progeny were crossed to remove the Flp-expressing transgene. These Fgf21loxP mice were bred to C57BL/6 mice for at least 10 generations. Upon arrival, mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.
|Allele Name||targeted mutation 1.2, David J Mangelsdorf|
|Allele Type||Targeted (Conditional ready (e.g. floxed), No functional change)|
|Gene Symbol and Name||Fgf21, fibroblast growth factor 21|
|Strain of Origin||129S6/SvEvTac|
|Molecular Note||A targeting vector was designed to insert a loxP site upstream of exon 1, followed by a second loxP site and a frt-flanked neomycin resistance (neo) cassette downstream of exon 3. Flp-mediated recombination removed the neo cassette.|
When maintaining a live colony, homozygous mice may be bred together.
When using the Fgf21loxP mouse strain in a publication, please cite the originating article(s) and include JAX stock #022361 in your Materials and Methods section.