B6.129P2-Slc7a5^tm1.1Daca/J

Stock number: 027252
Product name: Slc7a5^fl
Research areas: Cell Biology Research, Metabolism Research, Research Tools

Description

Slc7a5^fl/fl floxed mice may be useful for studying the regulation of large neutral amino acids during protein synthesis.

Detailed description

Slc7a5^fl/fl floxed mice possess loxP sites flanking exon 1, including the initiation codon, of the Slc7a5 (solute carrier family 7 (cationic amino acid transporter, y+ system), member 5) gene. Slc7a5 encodes the catalytic subunit of the System L1-type (LAT1) amino acid transporter which mediates Na⁺-independent transport of large neutral amino acids (LNAA). LNAA such as leucine are required for full activation of the mTORC1 signaling pathway promoting protein synthesis and cell growth. 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 crossed to strains with germline cre expression, homozygous KO mice are embryonic lethal while heterozygous Slc7a5^+/- mice show no overt phenotype. When crossed to mice expressing cre in skeletal muscle, homozygous KO mice are viable and fertile. They exhibit decreased leucine and isoleucine concentrations and impaired mTORC1 signalling in gastrocnemius muscle, alongside reduced glucose tolerance, when fed a low (10%) protein diet.

When bred to mice expressing Cre-recombinase in double positive T cells, Slc7a5-null T cells lack mTORC1 activity and were unable to metabolically reprogram in response to antigen. They did not undergo clonal expansion or effector differentiation.

Development

A targeting vector was designed to insert a loxP sites flanking exon 1, including the initiation codon, of the Slc7a5 (solute carrier family 7 (cationic amino acid transporter, y+ system), member 5) gene. A frt-flanked neomycin resistance (neo) cassette fused to an internal ribosomal entry site (IRES) and a splice donor (SD) sequence, including a third loxP site, were placed downstream of exon 1. The construct was electroporated into (129X1/SvJ x 129S1/Sv)F1-Kitl⁺-derived E14 ES embryonic stem (ES) cells. Correctly targeted ES cells were injected into blastocysts and resulting chimeric males were bred with C57BL/6J females. Offspring, were bred with C57BL/6-Tg(CAG-Flpe)2Arte transgenic mice to delete the neo-IRES-SD cassette, and progeny were crossed to C57BL/6 mice to remove the Flp-expressing transgene. Resulting Slc7a5^fl/fl mice were bred to C57BL/6J mice for at least 7 generations. Upon arrival, mice were bred to C57BL/6J inbred mice (Stock No. 000664) for at least one generation to establish the colony.

Allele

Symbol: Slc7a5^tm1.1Daca
Name: targeted mutation 1.1, Doreen A Cantrell
MGI accession ID: MGI:5618433
Generation method: Targeted
Attributes: Conditional ready (e.g. floxed); No functional change
Marker symbol: Slc7a5
Marker name: solute carrier family 7 (cationic amino acid transporter, y+ system), member 5
Chromosome: 8
Strain of origin: 129P2/OlaHsd
Molecular note: The targeting vector contains loxP sites flanking exon 1, including the initiation codon. An FRT-flanked neomycin resistance (neo) cassette fused to an internal ribosomal entry site (IRES) and a splice donor (SD) sequence, followed by a third loxP site, are placed downstream of exon 1. Flp-mediated recombination removed the FRT-flanked neo-IRES-SD cassette.