C.129S4(B6)-Arg1^tm1.1Lky/J

Stock number: 015858
Research areas: Cell Biology Research, Metabolism Research, Research Tools

Description

A targeting vector was designed to insert an internal ribosome entry site (IRES)-enhanced yellow fluorescent protein (eYFP) fusion protein, downstream of the endogenous stop codon of the arginase (Arg1) gene. These mice may be useful for visualization of arginase-containing cells and their response to infection.

Detailed description

A targeting vector was designed to insert an internal ribosome entry site (IRES)-enhanced yellow fluorescent protein (eYFP) fusion protein, downstream of the endogenous stop codon of the arginase (Arg1) gene. These homozygous YARG mice are viable, fertile, and normal in size. Located in the cytoplasm of the liver and specifically in macrophages, arginase I converts L-arginine into L-ornithine and urea as the final step in the urea cycle. L-arginine can also be catabolized into Nitric oxide (NO), a secreted free radical which causes tissues damage and is also toxic to bacteria. Arginase I suppresses NO production by decreasing the amount of L-arginine available to the nitric oxide synthase (NOS) enzyme for conversion into NO and other reactive oxygen species (ROS). Nine days after infection with the helminth, Nippostrongylus brasiliensis, YARG mice exhibit accumulation of arginase I-expressing macrophages. As soon as two days after inoculation with chitin, a polysaccharide found in the exoskeleton of some invertebrates, these macrophages were present in the lung and peritoneum. These mice may be useful for visualization of arginase-containing cells and their response to infection.

Development

A targeting vector was designed to insert a floxed neomycin (neo) resistance cassette, followed by an internal ribosome entry site (IRES)-enhanced yellow fluorescent protein (eYFP) fusion protein, downstream of the endogenous stop codon of the arginase (Arg) gene. The construct was electroporated into 129S4/SvJae-derived PC3 embryonic stem (ES) cells. These PC3 cells contain a transgene expressing Cre recombinase under control of the protamine promoter (Tg(Prm-cre)700g), to delete the neo cassette in the male germline. Correctly targeted ES cells were injected into C57BL/6 blastocysts and the resulting chimeric males were bred to C57BL/6 females. The male offspring from this initial breeding lack the floxed neo cassette and were bred to female C57BL/6 mice to establish a colony of YARG mice. These mutant mice were backcrossed to BALB/cJ mice for at least 10 generations. Upon arrival at The Jackson Laboratory, mice were bred to BALB/cJ (Stock No. 000651) for at least one generation.

Allele

Symbol: Arg1^tm1.1Lky
Name: targeted mutation 1.1, Richard M Locksley
MGI accession ID: MGI:4453214
Generation method: Targeted
Attributes: Reporter
Marker symbol: Arg1
Marker name: arginase, liver
Chromosome: 10
Strain of origin: 129S4/SvJae-Tg(Prm-cre)70Og
Expressed genes: YFP,Yellow Fluorescent Protein,jellyfish
Site of expression: YARG mice exhibit accumulation of arginase I-expressing macrophages in the lung and peritoneum after helminth infection.
Molecular note: An IRES element linked to an enhanced YFP construct was inserted in exon 8 downstream of the endogenous stop codon and a floxed neomycin cassette. The neomycin selection cassette was excised in male mice by cre expressed from the Prm1 promoter.