STOCK Arf1^{tm1c(EUCOMM)Wtsi}/HousJ

Stock number: 037055
Product name: Arf1^fl
Research areas: Neurobiology Research, Research Tools

Description

Exons 2-5 of the mouse Arf1 gene are flanked by loxP sites in these Arf1^fl mice. Cre recombinase-mediated excision of the floxed region results in a knock-out allele useful in studies of lipid metabolism, cancer, and neurodegeneration.

Detailed description

Arf1 (ADP-ribosylation factor 1) encodes a key protein that controls lipid metabolism. Ablation of the gene can kill cancer stem cells. Knock-out of the gene in neurons will cause peroxidated lipid accumulation in neurons, and induce NLRP3 inflammasomes in microglia; the activated microglia will kill neurons, causing neurodegeneration.

Exons 2-5 of the mouse Arf1 gene are flanked by loxP sites in these Arf1^fl mice. Cre recombinase-mediated excision of the floxed region results in a knock-out allele.

When crossed with mice expressing UBC-CreER (Stock No. 007001) to knock out expression of Arf1, progeny injected with tamoxifen become paralyzed after 20 days (Wang, 2021).

A mouse model combining this Arf1^fl allele, Lgr5-CreERT2 (Stock No. 008875), and Apc^f/f (Stock No. 009045) has demonstrated that knockdown of ARF1 dramatically reduces stem cell tumor numbers, and significantly extends the lifespan of the compound mutant mice (Wang, 2020).

Development

Arf1 embryonic stem cells carrying the Arf1^{tm1a(EUCOMM)Wtsi} mutation were purchased from the International Mouse Phenotyping Consortium (IMPC). This mutation was created by inserting the L1L2_Bact_P cassette at position 59214009 of mouse Chromosome 11. This vector introduced an FRT-lacZ-loxP-neo-FRT-loxP cassette to intron 1 of the mouse Arf1 gene and a loxP site to intron 5. The mutation was created in C57BL/6N-A^tm1Brd-derived JM8A3.N1 embryonic stem (ES) cells. Mice were crossed with animals expressing Flp recombinase to excise the lacZ and neomycin components at NCI-Frederick, NIH. The resultant Arf1^f allele carries exons 2-5 flanked by loxP sites. This line was backcrossed to C57BL/6J (Stock No. 000664) for more than 10 generations by the donating laboratory (see SNP note below). Upon arrival at The Jackson Laboratory, it was bred at least one additional generation to C57BL/6J.

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. Two of the 43 markers throughout the genome were segregating with and unknown source. Also, 4 of the 5 markers that determine C57BL/6J from C57BL/6N were found to be segregating, including the rd8 recessive mutation associated with retinal degeneration on Chromosome 1 within the Crb1 locus. These data suggest the mice sent to The Jackson Laboratory Repository were on a mixed genetic background.

Allele

Symbol: Arf1^{tm1c(EUCOMM)Wtsi}
Name: targeted mutation 1c, Wellcome Trust Sanger Institute
MGI accession ID: MGI:6196209
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed)
Synonyms: Arf1^fl
Marker symbol: Arf1
Marker name: ADP-ribosylation factor 1
Marker synonyms: PVNH8
Chromosome: 11
Strain of origin: C57BL/6N-A^tm1Brd
Molecular note: The L1L2_Bact_P cassette was inserted at position 59102857 of Chromosome 11 upstream of the critical exon(s) (Build GRCm39). The cassette is composed of an FRT site followed by lacZ sequence and a loxP site. This first loxP site is followed by a neomycin resistance gene under the control of the human beta-actin promoter, SV40 polyA, a second FRT site and a second loxP site. A third loxP site is inserted downstream of the targeted exon(s) at position 59104835. The critical exon(s) is/are thus flanked by loxP sites. A "conditional ready" (floxed) allele was created by flp recombinase expression in mice carrying this allele to remove the lacZ sequence and neo selection cassette, leaving loxP sites flanking the critical exon(s). Further information on targeting strategies used for this and other IKMC alleles can be found at http://www.informatics.jax.org/mgihome/nomen/IKMC_schematics.shtml