B6.Cg-Fgf15^{tm1.1(cre)Thor}/J

Stock number: 036431
Product name: Fgf15^CretdT , Fgf15-T2A-cre-T2A-tdTomato
Research areas: Neurobiology Research, Research Tools

Description

Fgf15^CretdT reporter mice express cre recombinase and tdTomato from the mouse Fgf15 (fibroblast growth factor 15) locus. Fluorescence detection reveals that tdTomato is expressed in all enterocytes lining the ileum villi, the main site of Fgf15 expression. In brain, no fluorescent signal is detected, suggesting that the level of tdTomato expression directed by the brain Fgf15 promoter is too low. Stereotactic injection of cre-dependent adeno associated viruses indicate that cre is expressed in the dorsomedial hypothalamus, perifornical area and medial habenula.

Detailed description

Activation of neurons expressing Fgf15 (fibroblast growth factor 15) leads to increased hepatic neoglucogenesis and decreased glucagon secretion.

Fgf15^CretdT reporter mice express cre recombinase and tdTomato from the mouse Fgf15 locus. As the knock-in is located downstream of the Fgf15 coding sequence, no effect on protein expression is anticipated. Fluorescence detection reveals that tdTomato is expressed in all enterocytes lining the ileum villi, the main site of Fgf15 expression. In brain, no fluorescent signal is detected, suggesting that the level of tdTomato expression directed by the brain Fgf15 promoter is too low. Stereotactic injection of a cre-activated adeno associated virus in the dorsomedial hypothalamus, perifornical area, and medial habenula (rAAV2-Ef1a-DIO-eYFP) leads to expression of eYFP in Fgf15 neurons.

Development

A T2A-cre-T2A-tdTomato cassette was introduced downstream of the Fgf15 coding sequence via homologous recombination in B6.Cg-Thy1^a-derived Bruce 4 embryonic stem (ES) cells. An FRT-flanked PGK-neomycin cassette located 3' of the stop codon was excised through crosses with Flp recombinase-expressing mice. Male chimeric mice were crossed with C57BL/6J females. This strain was maintained on a C57BL/6 background by the donating laboratory.

In 2022, a 48 SNP (single nucleotide polymorphism) panel analysis, with 43 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 males sent to The Jackson Laboratory Repository. One of the 5 markers that determine C57BL/6J from C57BL/6N was found to be segregating on Chromosome 8. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed C57BL/6N;C57BL/6J genetic background.

Allele

Symbol: Fgf15^{tm1.1(cre)Thor}
Name: targeted mutation 1.1, Bernard Thorens
MGI accession ID: MGI:6711269
Generation method: Targeted
Attributes: Recombinase-expressing; Reporter
Synonyms: Fgf15^CretdT
Marker symbol: Fgf15
Marker name: fibroblast growth factor 15
Marker synonyms: FGF19; Fgf8a
Chromosome: 7
Strain of origin: B6.Cg-Thy1^a
Molecular note: A T2A-cre-T2A-tdTomato cassette was introduced just before the stop codon in exon 3 of the mouse Fgf15 gene via homologous recombination in embryonic stem (ES) cells. An FRT-flanked PGK-neomycin cassette located 3' of the stop codon was excised through crosses with Flp recombinase-expressing mice.