FIT2L/L floxed mice possess loxP sites flanking exon 1 of the Fitm2 gene making this strain useful for studying the regulation of adipocyte lipid storage.
David L. Silver, Duke-NUS Graduate Medical School
FIT2L/L floxed mice possess loxP sites flanking exon 1 of the fat storage-inducing transmembrane protein 2 (Fitm2) gene. FIT2 is highly expressed in white and brown adipose tissue and plays a role in the formation and regulation of lipid droplets. Mice that are homozygous for this allele are viable and fertile. When bred to mice that express tissue-specific Cre recombinase, resulting offspring will have exon 1 deleted in the cre-expressing tissues.
When bred to aP2-Cre mice (Stock No. 005069), expressing Cre recombinase in differentiated adipose tissue, resulting AF2KO offspring exhibit progressive lipodystrophy of white adipose tissue, inflammation, insulin resistance, and metabolic dysfunction. This phenotype is accelerated on a high fat diet and on the genetically obese ob/ob background.
A targeting vector was designed by Dr. David L. Silver (Duke-NUS Medical School, Singapore) to insert a loxP site upstream of exon 1, and a frt-flanked neomycin cassette, followed by a second loxP site, downstream of exon 1 of the fat storage-inducing transmembrane protein 2 (Fitm2) gene. The construct was electroporated into (129S6/SvEvTac x C57BL/6J)F1-derived PTL1 embryonic stem (ES) cells. Correctly targeted ES cells were injected into C57BL/6 blastocysts and resulting chimeric mice were bred with B6;SJL-Tg(ACTFLPe)9205Dym/J mice (Stock No. 003800) to delete the neo cassette. Progeny were crossed to remove the Flp-expressing transgene, and resulting FIT2L/L mice were bred to C57BL/6NTac mice for 2 generations. 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).
|Allele Name||targeted mutation 1.1, David L Silver|
|Allele Type||Targeted (Conditional ready (e.g. floxed))|
|Gene Symbol and Name||Fitm2, fat storage-inducing transmembrane protein 2|
|Strain of Origin||(129S6/SvEvTac x C57BL/6J)F1|
|Molecular Note||A loxP site was inserted upstream of exon 1. An FRT-flanked neomycin resistance cassette with a 3' loxP site was inserted downstream of exon 1. Flp-mediated recombination removed the selection cassette and left exon 1 floxed.|
When maintaining a live colony, homozygous mice may be bred together.
When using the FIT2L mouse strain in a publication, please cite the originating article(s) and include JAX stock #028832 in your Materials and Methods section.